1879. Arcopagella? macrodonta Meek. U. S. Geol. Surv. Territories, vol. IX, pp. 202, 203, pl. 1, fig. 2.
1893. Arcopagella? macrodonta Boyle. Bull. 102, U. S. Geol. Surv., p. 60 (not described).
Meek's description. Shell trigonal, compressed, with height equaling about three-fourths the length; dorsal margin sloping rather abruptly, tod nearly equal from the beaks in front and posteriorly, the anterior margin being straight and the posterior a little convex in outline; basal margin forming a regular semielliptic curve; extremities subangular; surface unknown; lateral teeth of hinge long, linear and compressed. Length, 0.93 in.; height, 0.70 in.
The specimen on which Meek founded his description consisted of an imperfect mold of the interior of a right valve. The pallial line was not preserved, and if cardinal teeth were present they had not been preserved. Impressions which be considered indicative of the lateral teeth were present both in front and posterior to the beak, and as these were similar to what they are in the genus Arcopagella, he referred the shell to that genus.
Horizon and locality. Meek's specimen was derived from a horizon in the "Dakota" sandstone three miles above the mouth of Big Sioux river in South Dakota. Logan identified the species from thin sandstone layers in the Saliferous shales of the Upper "Dakota" of Kansas.
1871. Arcopagella mactroides Meek. Hayden's Second Ann. Rept. U. S. Geol. Surv. Territories, p. 309, wood cuts A and B.
1878. Arcopagella mactroides Meek. U. S. Geol. Surv. Territories, vol. IX, p. 202, pl. 2. figs. 4a-d.
1893. Arcopagella mactroides Boyle. Bull. 102, U. S. Geol. Surv., p. 60 (not described).
Meek's description. Shell longitudinally ovate; width and height about two-thirds the length, rather compressed and moderately convex; pallial margin forming a regular semielliptic curve from end to end; anterior margin narrowly rounded with the more prominent part near the middle; posterior border more narrowly rounded than the anterior, particularly below, where there seems to be the faintest possible tendency to form a flexure or fold; beaks moderately prominent, located very nearly centrally; dorsal outline sloping almost equally before and behind the beaks, but with the anterior slope slightly concave in outline above, and the posterior, a little convex; muscular impressions faintly marked and rather narrow-subovate; pallial line with its rather shallow, broadly rounded sinus directed very obliquely forward and upward. Surface apparently with only fine lines of growth. Length of one of the larger specimens, 0.78 in.; height, 0.53 in.; convexity, about 0.26 in.
Meek states that this shell is proportionately smaller and of a different general outline from A? macrodonta.
Horizon and locality. Mentor beds. Meek's locality is stated to have been twelve miles southwest of Salina, Kan. The shell, is common in the Mentor beds five miles west of Smolan, in Saline County.
1872. Arca? parallela Meek. Hayden's Second Ann. Rept. U. S. Geol. Surv. Territories, p. 3.
1876. Barbatia (Polvema?) parallela Meek. U. S. Geol. Surv. Territories, vol. IX, pp. 80, 81, pl. 2, fig. 10. 1893. Barbatia (Polvema?) parallela Boyle. Bull. 102, U. S. Geol. Surv., p. 69 (not described).
Meek's description. Shell small, longitudinally oblong, being about twice and a half as long as high, moderately convex, cardinal and pallial margins straight and nearly parallel; anterior side short, rounding up regularly from below, and intersecting the cardinal margin at an obtuse angle above; posterior side long, a little wider than the other, with its margin compressed and obliquely truncated above, but rounded below; beaks depressed, somewhat flattened, incurved, not very remote, and placed about one-fifth the length of the valves from the anterior margin; cardinal area very narrow, and apparently smooth, only marked with one or two longitudinal cartilage furrows; muscular and pallial impressions very obscure, hinge with denticles longest posteriorly, where they are directed upward and backward at an angle of about 45 degrees to the cardinal margin; from the posterior side they diminish rather rapidly in size and length forward, so as to become very minute and crowded between the beaks, which is as far forward as they have been traced in the specimens examined. Surface showing very fine, crowded, radiating strise, with strong marks of growth. Denticles were also believed by Meek to be present in front of the beak. Length, 0.95 in.; height, 0.37 in.; convexity, 0.27 in.
Horizon and locality. Meek's specimens came from 12 miles to the southwest of Salina and were collected from a red sandstone, which is probably the Mentor bed. No specimens of this species have been found in the collections of the writer.
1894. Cardita belviderensis Cragin. Am. Geol,, vol. IV, p. 5, pl. 1, figs. 9-11.
1895. C. belviderensis Hill. Am. Jour. Sci., vol. L, p. 214 et al, (not described).
1900. C. belviderensis Stanton. In Gould, Am. Geol., vol. XXV, p. 37 (not described).
Cragin's description (in part). Shell of small to medium size, triangular or cordiform, moderately to rather strongly ventricose; beaks placed near the anterior side and directed strongly forward; exterior of either valve ornamented with about 26 ribs, of which 19 or 20 are narrow, prominent, spiniferous, and separated by valleys about twice as wide as themselves, the other 6 or thereabout being low, plainer, and crowded; spines of the larger ribs much more closely set than the ribs themselves, short, erect, subtruncated (commonly appearing as little more than coarse granules owing to the weathering of the shell); margin of valves deeply notched.
A large specimen is about 28 mm. high, 27 mm. wide, and about 8 mm. deep for one valve. Most specimens are from one-half to two-thirds these dimensions.
Horizon and locality. This shell is quite abundant in the Champion shell bed. It is rarely present in zones 8 to 12 of the Champion Draw sections. It has also been collected in the basal zones of the Bluff Creek section.
1894. Cardium (Nemocardium) bisolaris Cragin. Am. Geol., vol. XIV, pp. 6, 7, pl. I, fig. 16.
Cragin's description. Shell small, quadrilaterally or subtriangularly rotund, of moderate convexity; beaks subcentral, slightly in advance of the middle; posterior fourth (or less than fourth) part of outer surface ornamented with thirty or more slender, radial costellae, the anterior three-fourths being devoid of concentric costellae and marked with extremely delicate and crowded radial striae; inner part of free margin delicately notched or crenulated. The costellae of the posterior part are not visibly echinate in the types. Measurements: Height, 23 mm.; length, 21 mm.; breadth, 15 mm.
The writer has not found any specimens which correspond with this description so far as the differentiation of the radiate striae are concerned. It is possible that Cragin had variants of Cardium kansasense.
Horizon and locality. Cragin states that the shell is moderately common in his zone 6, which corresponds with the Champion shell bed. The writer has not seen the shell if it be distinct from C. kansasense.
1871. Cardium kansasense Meek. Hayden's Second Ann. Rept. U. S. Geol. Surv. Territoriet, pp. 307, 308.
1876. Cardium? kansasense Meek. Rept. U. S. Geol. Surv. Territories, vol. IX, pp. 170, 171, pl. 2, figs. 14a-d.
1889. Cardium kansasense Cragin. Bull. Wash. Coll. Lab. Nat. Hist., vol. II, No. 10, p. 67 (not described).
1890. Cardium kansasense and C. belviderei Cragin. Ibid., No. 11, pp. 75, 76, 77 (not described).
1891. Cardium kansasense and C. belviderei Cragin. Am. Geol., vol. VII, pp. 26, 27 (not described). 1893. Cardium kansasense Boyle. Bull. 102, U. S. Geol. Surv., p. 78 (not described).
1895. Cardium kansasense Cragin. Am. Geol., vol. XVI, p. 165 (not described).
1900. Cardium kansasense Gould. Am. Geol., vol. XXV, p. 87 (not described).
Meek's description. Shell rather small, oval-suborbicular, being generally slightly higher than the anteroposterior diameter, and rather gibbous, with the greatest convexity usually above the middle; pallial margin rounded, or subsemicircular in outline, being in most cases most prominent behind the middle; anterior margin more or less regularly rounded; posterior outline rounded, or very faintly subtruncated; dorsal outline sloping abruptly from the beaks before and behind; beaks elevated, gibbous, incurved and subcentral, or a little in advance of the middle, and but slightly oblique; posterior dorsal slopes somewhat flattened; surface marked by numerous regular, simple, radiating striae, or small costae, that are sometimes interrupted by marks of growth. Hinge strong, with cardinal and anterior lateral teeth stout; posterior lateral remote and less prominent. Anterior muscular scar rather deep; posterior shallow. Scar of pedal muscle (?) small, very deep, and situated on the inner anterior side, and near the points of the beaks, almost opposite the cardinal teeth, as shown (p of fig. 14d).[Note: This reference is to Meek's plate.] Length, 0.94 in.; height, 1 in.; convexity, about 0.63 in.
Meek further states that no "traces of nodes or projecting points of any kind exist on the costae of this species." In this statement he was in error, as such are shown in well-preserved molds of the exterior.
Horizon and locality. This is one of the most common shells of the Mentor beds and it has been seen at every occurrence. It is also present in abundance in the Windom member. In the Kiowa shales it is extremely abundant in zones 8, 10 and 12, but is present from the Champion shell bed to the top. The forms in the Champion shell bed are small. It has about the same distribution in other exposures.
(?Cardium) mudgei Cragin
1895. (?Cardium) mudgei Cragin. Am. Geol., vol. XIV, p. 6.
Cragin's description. Size apparently about that of Cardita belviderensis shell ornamented with heavy, narrowly interspaced, round-topped, radial ribs, and with numerous freely projecting, concentric, lamellar borders, which are relatively more prominent in crossing the ribs than elsewhere, forming thereupon strong hood-like imbrications. Within a space of 9 millimeters on the ventral margin of the type specimen there are 5 ribs, and on the largest one of the ribs there are, on the distal 7 millimeters of its length, 9 of the hood-like imbrications.
Cragin states that only a single valve of this shell was found by him. From this he could not definitely determine the generic place of the shell. He compares the ornamentation to that of Axinaea subimbricata Meek and Hayden. As this ornamentation is quite different from that of Cardium kansasense, it precludes the possibility that he had a valve of the latter. No shell of this species has been seen by the writer.
Horizon and locality. Cragin collected his shells from his zone 3 of the Belvidere section, which includes the limestone zones of the writer's section numbered 8 to 12 or 14. The shell was not seen elsewhere.
1872. Corbicula? subtrigonalis Meek. Hayden's Second Ann. Rept. U. S. Geol. Surv. Territories, p. 305.
1876. Corbicula? subtrigonalis Meek. U. S. Geol. Surv. Territories, vol. IX, pp. 164, 165, pl. 2, fig. 6.
1893. Corbicula? subtrigonalis Boyle. Bull. 102, U. S. Geol. Surv., pp. 93 (not described).
Meek's description. Shell oval-subtrigonal, about one-fourth longer than wide, rather gibbous, the greatest convexity being above the middle; basal outline forming a semielliptic curve; extremities rather narrowly and very nearly equally rounded; beaks somewhat depressed and very nearly central; dorsal outline sloping before and behind the beaks, the latter slope being convex and the former nearly straight. Surface only showing fine lines of growth. Pallial line with a small, obtusely subangular sinus. Length, 1.16 in.; height, 0.90 in.; convexity, about 0.66 in.
Meek saw but one mold of the hinge of this species, and this showed lateral teeth similar to C? nucalis, The other teeth were so poorly preserved as to be rather indeterminate. The form is said to differ from C? nucalis in having a more depressed and transverse outline, its lateral extremities more nearly equal and more narrowly rounded and the posterior margin not truncated.
Horizon and locality. Mentor beds. Meek's specimens came from 12 miles to the southwest of Salina, which is somewhere in the vicinity of Smolan. The species has not been seen in the writer's collection.
Shell small, elongate-oval, posterior extremity narrowed, beak in front of the middle; maximum length, 9 to 10 mm.; height about 6 mm.; thickness for both valves, 4 mm. Hinge structures not well preserved, but appear to be corbiculoid. Surface concentrically striated by fine lines. Both anterior and posterior muscle scars well developed, elevated above surface with the anterior edge of the anterior scar projecting. Pallial sinus small, merely a circular indentation.
Horizon and locality. Mentor beds, 5 miles west of Smolan, and at Mentor.
1872. Corbicula? nucalis Meek. Hayden's Second Ann. Rept. U. S. Geol. Surv. Territories, p. 394.
1876. Corbicula? nucalis Meek. U. S. Geol. Surv. Territories, vol. IX, p. 163-164, pl. 2, figs. 5a-c.
1893. Corbicula? nucalis Boyle, Bull. 102, U. S. Geol. Surv., p. 92 (not described).
Meek's description. Shell small, trigonoid-suborbicular, gibbous, the greatest convexity being a little above the middle; basal margin forming nearly a semielliptic curve; posterior subtruncated or rounded; anterior margin rather narrowly rounded, its most prominent part being below the middle; dorsal outline sloping rather abruptly, and nearly equally in both directions, with slight convexity of outline near the beaks behind, and about the same concavity in front; beaks nearly or quite central, incurved, with slight forward , obliquity; posterior dorsal surface sometimes very slightly furrowed immediately behind the umbonal slope in internal casts; muscular impressions shallow, comparatively rather large, and arcuate-subovate in form; pallial line with a shallow, obtuse sinus. External surface unknown; that of cast smooth. Length, 0.47 in.; height, 0.42 in.; convexity, 0.26 in.
Meek observed the presence in the mold of the right valve of "long transversally striated double lateral teeth." He thought that he observed the presence of the cardinal teeth, the anterior cardinal tooth of the left valve being directed almost horizontally forward, much compressed from above and below, very prominent, and curved upward. "The corresponding tooth of the other valve is much smaller and overlaps that of the right valve. I think I have seen two other diverging and emarginate cardinal teeth, with pits for two corresponding diverging teeth in the right valve."
Horizon and locality. Mentor bed; 12 miles southwest of Salina, probably the locality to the west of Smolan. The writer has not seen the species in any of his collections.
1894. Corbula crassicostata Cragin. Colorado Coll. Studies, 5th Ann. Publication, p. 61.
Cragin's description. Shell triangular-ovate, gibbous, nearly as broad as high, short; gaping posteriorly by a short, conically inflated, gently truncated rostrum, which is placed above the base of the shell; umbones placed in advance of the middle, that of the right valve only moderately high arched, its summit obtuse; surface ornamented with very coarse, flattish-topped, concentric ribs, separated by abrupt, deep, narrow intervals. There are seven or eight of the ribs on the basal half of a right valve the same number of millimeters high. Measurements: Height, 7.5 mm.; length, breadth, about 7 mm.
There is about one of the concentric ridges to a millimeter. The separating depressions are round-bottomed. The tops of the ridges appear to be slightly depressed along their middle. This, however, is not positive. There are also indications that both ridges and the separating depressions are ornamented by concentric striae. The hinge structure is not known.
Horizon and locality. Cragin obtained his specimens in the limestone bands of the Kiowa shales. He also identified the species in the Denison beds at Denison, Tex. It appears to be rather common in the Champion shell bed and less commonly in higher strata of the Kiowa shales.
1871. Crassatellina oblonga Meek. Hayden's Second Ann. Rept. U. S. Geol. Surv. Territories, p. 201, wood cuts A and B.
1876. Crassatellina oblonga Meek. U. S. Geol. Surv. Territories, pp. 120, 121, pl. 2, figs. 3a-e.
1893. Crassatellina oblonga Boyle. U. S. Geol. Surv., Bull. 102, p. 103 (not described.)
Meek's description. Shell small, short oblong-subtrapezoidal in outline, less than twice as long as high; valves rather distinctly convex, with flattened sides; anterior margin rounded; pallia! margin nearly straight, or sometimes slightly sinuous along the middle; posterior obliquely truncated above and narrowly rounded below; dorsal outline sloping rather abruptly in front of the beaks, and less indistinctly so behind; beaks moderately prominent, and placed a little in advance of the middle; posterior umbonal slopes prominently rounded from the beaks to posterior basal extremity; posterior dorsal region above the umbonal prominences flattened; flanks sometimes a little concave toward the pallial margin. Surface with rather distinct lines of growth. Length, 0.73 in.; height, 0.32 in.; convexity, 0.30 in.
Horizon and locality. The specimens studied by Meek came from the Mentor beds and were collected from exposures twelve miles southwest of Salina. The writer's specimens came from 5 miles west of Smolan and the Natural Corral.
This species is represented by several molds of interiors, but the specimens are so large in comparison with C. recedens that they have been considered to merit differentiation as new forms. The largest of the specimens is 80 mm. long, 70 mm. high and 60 mm. thick. With the shell present the dimensions must have been considerably greater. The shape appears to be essentially that of C. recedens, except that the beak is relatively farther back from the anterior end of the shell.
It is possible that these specimens ought not be referred to the genus Cucullaea, as no portion of the hinge area is shown, but the shape is so like that of C. recedens that it is confidently referred to the same genus.
Horizon and locality. The specimens were collected in the Mentor beds at the Natural Corral, McPherson County.
1890. Idonearca vulgaris Conrad, Cragin. Bull. Washburn Coll. Lab. Nat. Hist., vol. I, No. 11, pp. 76-79 (not described).
1891. Idonearca vulgaris Cragin. Am. Geol., vol. VII, p. 26 (not described). Also identified as Idonearca tippiana.
1891. Idonearca tippiana Conrad Cragin. Ibid., p. 76 (not described).
1893. Cucullaa terminalis (partim) Cragin. Fourth Ann. Rept.. Geol. Surv. Tex., p. 174.
1894. Cucullaa terminalis recedens Cragin. Am. Geol;, vol. XIV, pp. 8, 4, pl. I, fig. 19.
The shape is triangular, ovate, beak and umbo prominent, the former slightly projecting over the hinge area and situated from one-fourth to one-fifth the length of the shell from the anterior margin and nearly in the middle of the hinge line. Ventral margin quite uniformly curved, joining with the anterior end of the hinge line at about a right angle. Trending backward from the beak is a strong rounded ridge where the main portion of the surface meets that posterior to the ridge at an angle of 110 to 120 degrees. This posterior portion is gently concave to the margin. The hinge line in an average example is 30 to 35 mm. long. The area is marked by ridges radiating from the beak. The dentition is taxodont, the ridges and grooves chevron-shaped--except middle portion, where straight--with the angle directed toward the axis of the shell. An average example is about 7 mm. long, 45 to 50 mm. high and 40 mm. thick for both valves. The surface ornamentation consists of strong concentric growth lines.
The shell differs from C. terminalis, with which it has been identified, in having the beaks not nearly so terminal.
Horizon and locality. Extremely abundant and large in the Champion shell bed at Champion Draw. Occurs rarely in higher strata and is somewhat smaller in the limy beds of zones 8 to 14. One specimen with radiating lines on one portion of the mold of the interior was collected in the Mentor beds at the locality 5 miles west of Smolan, and smaller specimens with the lines less marked have been collected at the Natural Corral.
1890. Cyprimeria crassa Cragin. Bull. Washburn Coll. Lab. Nat. Hist., vol. 2, No. 9, p. 35 (not described).
1890. C. gradata Cretin. Ibid., p. 36 (not described).
1890. C. crassa Cragin. Ibid., No. II, p. 75 (not described).
1890. C. gradata Cragin. Ibid., p. 75 (not described).
1892. C. crassa Cragin (in part). Fourth Ann. Rept. Tex. Geol. Surv., p. 176.
1894. C. texana Cragin. Colorado Coll. Studies, No. 6, p. 67 (not described).
1895. C. texana var. kiowana Cragin. Am. Geol., vol. XVI, pp. 369, 372 (not described).
1895. C. sp. Stanton. In Hill, Am. Jour. Sci., vol. 50, p. 217.
1900. C. texana var. kiowana Stanton. In Gould, Am. Geol., vol. XXV, p. 37 (not described).
The shell is nearly uniformly convex, and the outline, except for a small portion in the umbonal region, is almost a circle. In front of the beak the surface is slightly depressed over a small area. Surface ornamented by concentric growth lines which on the umbonal portions are very faint and inconspicuous; but are well developed about the margins, some being so prominent as to give a terraced appearance to those portions of the shell. Escutcheon and lunule poorly developed.
Anterior muscle scar narrowly elliptical, acute above, slightly elevated above the interior surface. Posterior scar not well defined. Pallial sinus very faintly marked. Three cardinal teeth in left valve, two in right; posterior cardinal of each valve bifid.
C. kiowana differs from C. texana in being thicker and about one and a half times as large. From C. crassa as described by Meek it differs in having a more convex surface and being of greater length and height.
For comparison the dimensions of the three species are given:
|C. texana1||C. crassa2||C. kiowana|
|Height||53 mm||1.93 in.||77 mm|
|Length||55 mm||2.00 in||79 mm|
|Thickness||14 mm||1.00 in.3||30 mm|
|1. Cragin, Fourth Ann. Rept. Texas Geol. Surv., 1892, p. 176.
2. Meek, Exploring Expedition from Santa Fe to the Junction of Grand and Green Rivers, 1869, p. 128.
3. Meek does not give the thickness; it was derived by measuring his figure.
Human and locality. C. kiowana occurs in great abundance in zones 8, 10 and 12 of the Champion Draw section. It is also present in the Champion shell bed and zone 18. It is equally as abundant in the equivalent zones to the west of Sun City and the Bluff Creek sections. It also has been found in the Mentor beds at the Natural Corral and the Windom member at that locality and near Windom.
1857. Cyprina arenaria Meek and Hayden. Proc. Philadelphia Acad. Nat. Sci., p. US.
1864. Cyrena arenaria Meek. Smithsonian Check-list Cret. Mollusks, p. 13.
1885. Cyrena dakotensis Meek and Hayden. MS., Prime, Monogr. Am. Corbiculidae, p. 31.
1876. Cyrena dakotensis Meek. U. S. Geol. Surv. Territories, vol. IX, pp. 169, 180, pl. 1, figs. 1a-f.
1893. Cyrena dakotensis Boyle. U. S. Geol. Surv. Bull. 102, p. 111 (not described).
Meek's description (1876). Shell subcircular, or very broad-subovate, moderately convex; anterior and posterior margins rather abruptly rounded; base forming a semioval curve; dorsal outline sloping from the beaks, the anterior slope being abrupt, little concave, and the posterior convex. Beaks rather elevated and subcentral; anterior muscular impression narrow-ovate, well defined; posterior broader and more shallow. Pallial line distant, nearly simple, or very faintly sinuous just beneath the posterior muscular scar. Surface marked by more or less distinct concentric strife. Length, 1.20 in.; height, 1 in.; convexity, about 058 in.
Horizon and locality. Meek obtained the specimens figured by him from the "Dakota" sandstones near the mouth of the Big Sioux river in southeastern South Dakota. The species has been identified by Logan from the upper "Dakota" of Kansas.
1849. Exogyra texana Roemer. Texas, Bonn, pp. 369, 897.
1852. Exogyra texana Roemer. Kreidebildung von Texas, Bonn., pp. 69, 70, taf. 10, figs. 1a-c.
1889. Exogyra texana Cragin. Bull. Washburn Coll. Lab. Nat. Hist., vol. 2, No. 9, p. 36 (not described).
1889. Exogyra flabellata Cragin. Ibid., No. 11 (not described).
1891. Exogyra flabellata Cragin. Am. Geol., vol. VII, p. 26 (not described).
1893. Exogyra texana Boyle. U. S. Geol. Surv., Bull. 102, p. 125 (not described).
1895. Exogyra texana Stanton. In Hill, Am. Jour. Sci., vol. L, p. 216 (not described).
The valves of this shell are quite thick and subequal. The outline is elongate and elliptical, the largest individual being 75 mm. long and about 55 mm. wide. The margin is indented near the beak. Beak much twisted, making almost a complete circle. A ridge extends spirally backwards from the posterior margin on the beak, making nearly a complete revolution. Near the beak its apex is abrupt and the surface of the shell is deflected nearly at right angles. Backward from the beak this ridge becomes lower and less acute and ultimately it merges into the surface.
The surface is ornamented with coarse branching ribs of irregular length. Most of these begin anterior to the ridge described above. Some branches cross the ridge and reach the posterior margin at an angle of about 60 degrees. Other branches trend ventralward and reach the anterior margin.
Compared with specimens from Texas, those from Kansas are somewhat more elongated. In other respects they appear to be the same.
Horizon and locality. Eleven valves have been collected. Six of these came from the Champion shell bed, four from Champion Draw, and two from west of Sun City. One specimen was collected in zone 8 of the Champion Draw section and four from the lower Gryphaea zone of Bluff creek. The shell occurs more or less abundantly throughout the Fredericksburg of the Texas and Mexican regions, and it is also present in the Washita formation. Stanton has identified it from the Washita of Tucumcari, N. Mex., and localities in Oklahoma.
1880. Gervillia mudgeana White. Proc. U. S. Nat. Mus., Smithson Misc. Coll., vol. 19, pp. 296, 298, pl. V, figs. 3, 4.
1883. Gervillia mudgeana White. Twelfth Ann. Rept. U. S. Geol. and Geol. Surv. Territories, pt. I, pp. 16, 17, pl. 14, figs. 3a-b.
1893. Gervillia mudgeana Boyle. U. S. Geol. Surv., Bull. 102, p. 136 (not described).
White's description. (Additional characters are given in italics.) This shell is known only by natural casts in brown hematite (limonite) of the interior and molds of the exterior. It is moderately large, laterally distorted; hinge line comparatively long, very oblique, with the axis of the shell producing a somewhat posterior alation, which is distinctly defined from the body of the shell; cartilage pits, at least seven in a full-grown individual; 5 mm. from center to center and 3 mm. wide and long; beaks placed very close to the anterior end, beyond which there appears to have been no very distinct anterior ear; beak of the right valve in mold more pronounced than that of the other, extending 8 mm. above the beak of the left valve. Right valve not so convex across the axis as the left; right valve having a somewhat regular and strong longitudinal convexity, but its transverse convexity is very little in the anterior half, while the posterior half is slightly concave. Left valve along the axis. nearly straight from beak to margin, very convex across the axis, particularly on opposite sides of the axis, the summit being quite gently rounded. Posterior to the axial portion of the shell the surface is flat or slightly concave to the hinge line, the boundary between this nearly flat portion and the steep portion marginal to the axis being quite sharp.
Except for the small but well-defined growth lines, the surface is ornamented by fine radial, lines from 1/2 to 1 mm. apart. The best mold of the exterior (left valve) has a length at the hinge line of 55 mm. and 75 mm. along the axis. The axial portion of the mold is 25 mm. wide at the margin; the flat posterior portion is 13 mm. at the margin. A nearly perfect mold of the interior has an axial length of 70 mm. Shell probably thin. The adductor scars are faintly shown in all the specimens collected by the writer. White's figure shows a large impression of elliptical outline situated just below the posterior portion of the hinge line.
The shell does not closely resemble any species known to the writer. In being tortuous it bears some resemblance to G. subtortuosa Meek and Hayden from the upper Cretaceous, but the resemblance goes no further.
Horizon and locality. Mentor beds, 5 miles west of Smolan; common. A single young specimen in both interior and exterior mold, from Natural Corral. A single specimen was also collected in the zone 10 of the Belvidere section.
1823. Gryphaea corrugata Say. Acct. of Exped. Pittsburg to Rocky Mountains, vol. II, Philadelphia, pp. 410, 411.
1889. Gryphaea pitcheri Cragin (in part). Bull. Washburn Coll. Lab. Nat. Hist., vol. 2, No. 9, p. 35 (not described).
1880. Gryphaea pitcheri Cragin. Ibid., No. 11, pp. 76, 76, 77 (not described).
1891. Gryphaea pitcheri Cragin. Am. Geol., vol. VII, pp. 25, 26, 27 (not described).
1895. Gryphaea forniculata Stanton and Hill. Am. Jour. Sci., 3d ser., vol. L., p. 216 (not described).
1895. Gryphaea pitcheri var. tucumcarii Cragin. Am. Geol., vol. XVI, pp. 371, 373. 1897. Gryphaea forniculata Vaughan. Am. Jour. Sci., 4th ser., vol. IV, p. 46 (not described).
1898. Gryphaea corrugata Hill and Vaughan. U. S. Geol. Surv. Bull. 161, pp. 63-67, pl. V, fig. 8; pl. VI; pl. VII; figs. 1-10, 16-17; pl. XI; pl. XII; pl. XV; pl. XVI; pl. XVIII, figs. 1-3; pl. XIX, figs. 1, 2.
This species resembles G. navia, but lacks the keel and the posterior prolongations of the valves which are present in that species. The surface also lacks the escarpments arising from the growth lines. The shells are more oval and less deep than are those of G. navia. An average example from the Champion shell bed is about 35 mm. wide, 55 to 60 mm. long and 20 to 25 mm. thick. The resilifer is cone-shaped, axis of the cone curved to become concave anteriorly and upward, 18 mm. long, 6 mm. wide, ridged by small elevations which are parallel to the hinge line. In higher horizons the shells are a little larger, but it is not certain that these are not young forms of the variety G. corrugata belviderensis.
Horizon and locality. Occurs in each of the Champion Draw Gryphaea beds, being common in the Champion shell bed and in the highest calcareous bed, but abundant in the middle horizons, where, as stated, it may be the young forms of G. corrugata belviderensis. It has a similar abundance in other sections of the southern part of the state. It has not been seen in the central part of Kansas.
In Texas, Hill and Vaughan state that it ranges from the upper portion of the Kiamitia shales into the Duck Creek beds. It is generally present in exposures of the Washita between Kansas and Texas.
1893. Gryphaea corrugata var. belviderensis Hill and Vaughan. U. S. Geol. Surv. Bull. 151, p. 56, pl. IX, figs. 1-3; pl. X, figs. 1, 2.
This shell is like the typical G. corrugata, except that it is very large and of somewhat more triangular shape. An average example is from 60 to 70 mm. wide, 75 to 85 mm. long, and 30 to 35 mm. deep. There is no keel which makes possible an easy separation from the large forms of G. navia with which it is associated.
Horizon and locality. This shell is found in all the limestone layers of the Kiowa shales except the Champion shell bed. It is particularly abundant in zones 14 and 16 of the Champion Draw section.
1891. Gryphaea pitcheri, var hilli Cragin. Am. Geol., vol. VII, p. 181 (not described).
1894. Gryphaea pitcheri var. "hilli phase" Cragin. Am. Geol., vol. XIV, p. 6 (not described).
1894. Gryphaea pitcheri var. hilli Cragin. Idem:, p. 10 (not described).
1885. Gryphaea hilli Cragin. Am. Geol., vol. XVI, pp. 368, 369, 371 (not described).
1898. Gryphaea corrugata var. hilli Hill and Vaughan. U. S. Geol. Surv. Bull. 151, pp. 20, 56.
This is a small variety of the C. corrugata type. The lower valve is boat-shaped and widens from the beak. In most specimens the beak is truncated by the flat surface of attachment and is generally slightly twisted. The shell is thick, surface in many specimens marked by low, rounded, radial ridges. A shallow radial furrow posterior to the axis of the shell. The convexity of the shell decreases toward the ventral margin. Length along the axial portion of the shell from the beak to the anterior margin--the chord of the arc--30 mm.; width across the axis (greatest) 20 to 30 mm.; depth averages 15 mm. The margins in many individuals wavy and crenulated; resilifer triangular cone-shaped with the axis of the cone curved, 3 to 3 1/2 mm. wide, 4 to 4 1/2 mm. long.
The upper valve is of irregular oval outline, narrowest at the hinge line. An average shell is 20 to 25 mm. long, 18 to 20 mm. wide, not over 2 to 3 mm. thick. Quite commonly a little concave outward over the ventral half. Lines of growth coarse. Muscular markings well defined in each valve.
Hill and Vaughan (Idem., p. 76) consider that this is an ancestral form of G. corrugata and state that it "shows comprehensive characters of the three forms of G. Marcoui, G. corrugata, and G. navia." Without dissenting from this view as to the possibility that it is an ancestral form, the writer wishes to suggest that it is a dwarfed form of G. corrugata developed by adverse conditions of environment, under which conditions there arose a reversion to ancestral characters.
Horizon and locality. Occurs in immense numbers in the Champion shell bed at Champion Draw and all other localities where that horizon is developed. Not in higher beds. Cragin states (1895, p. 370) that it is abundant in the Comanche Peak limestone and Walnut beds of Tarrant, Peak and Williamson counties, Texas. This statement is possibly based on mistaken identifications.
1856. Gryphaea pitcheri var. navia Hall. Rept. Expl. and Surv. R. R. from Miss. River to Pacific, vol. III, pt. IV, p. 100, pl. I, figs. 7-10.
1889. Gryphaea pitcheri Cragin (in part). Bull. Washburn Coll. Lab. Nat. Hist., vol. 2, No. 9, p. 35 (not described).
1890. Gryphaea pitcheri Cragin (in part). Bull. Washburn Coll. Lab. Nat. Hist. vol. 2, No. 11, pp. 75, 76, and 77 (not described).
1891. Gryphaea pitcheri Cragin (in part). Am. Geol., vol. VII, pp. 25, 26, 27 (not described).
1896. Gryphaea pitcheri var. roemeri (in part) Cragin. Am. Geol., vol. XVI, pp. 372, 374 (not described).
1898. Gryphaea navia Hill and Vaughan. U. S. Geol. Surv. Bull. 161, pp. 57-59, pla. XVII and XVIII, figs. 4-12.
The lower valve of this species is lopsided, boat-shaped, widens from the strongly incurved twisted beak, greatest width distally from the beak, ventral margin prolonged posteriorly 55 to 60 mm.; length 75 to 80 mm.; thickness, about 30 mm.; depth of cavity, 15 to 18 mm. Muscular scar sharply defined, slightly depressed. Lines of growth rough and sharply defined. A strong, well-marked keel is present, across which the lines of growth have sharp, steep, knoblike escarpments. Anterior to the keel is a radial furrow, in front of which in some specimens there is a second less distinct keel. Resilifer narrowly cone-shaped with axis bent to become concave anteriorly and ventrally, crossed by small ridges parallel to the hinge line, 12 to 15 mm. long, 7 to 8 mm. wide. Cardinal or hinge area ridged. Margins of valve distinctly crenulated.
The upper valve is irregularly oval and a ventral posterior prolongation widens from the beak; greatest width, 60 to 65 mm.; length, about 60 mm.; thickness, 3 to 4 mm. Lines of growth give surface a rough appearance. Surface slightly concave outward; margins distinctly crenulated; hinge area ridged.
Horizon and locality. Very abundant in zone 14 of the Champion Draw section of which zone it is characteristic, occurring in the ratio of about 2 to 1 of G. corrugata (keels here not knobby). It is also present in lower beds, but G. corrugata dominates. It has not been seen in the Champion shell bed. Forms with knobby keels are in the limestone zones above zone 14. It has not been observed in the highest Gryphaea beds of the Belvidere region nor was it observed in the equivalent beds of the Bluff Creek region although it occurs in the Lower Gryphaea beds of that locality.
In Texas this species is stated by Hill and Vaughan to be present in the Kiamitia clays (p. 95) and it has also been noted in exposures between Texas and Kansas.
Shell small, 10 to 12 mm. long, about half so high, about 4 mm. thick for both valves. Surface ornamented with fine concentric lines. Beak in front of mid-length, point turned posteriorly. Shell straight from beak to anterior margin, sharply and uniformly rounded to ventral margin; thence slightly convex to posterior margin, where so sharply rounded that the posterior end is acuminate, thence concave to beak. Structure of hinge and pallial markings not preserved. The shape of the shell is so essentially Leda-form that it is felt that no mistake is made in referring it to that genus. Preserved only as molds of the exterior and interior.
Horizon and locality. Mentor beds, 5 miles west of Smolan, and also at Mentor and Natural Corral. Common.
1872. Leptosolen conradi Meek. Hayden's Second Preliminary Rept. U. S. Geol. Surv. Territories, p. 311.
1878. Leptosolen conradi Meek. U. S. Geol. Surv. Territories, Hayden, vol. IX, pp. 253, 254, pl. II, figs. 12a-b.
1898. Leptosolen conradi Boyle., Bull. 102, U. S. Geol. Surv., p. 166 (not described).
1896. Leptosolen conradi Cragin. Am. Geol., vol. XVI, p. 164 (not described).
Meek's description. Shell enlongate-oblong, nearly three times as long as high, moderately convex; dorsal margin straight, pallial margin more or less nearly straight, and parallel to the dorsal, being a little convex in outline in front of the middle; thence ascending obliquely forward to the narrowly rounded anterior end; posterior margin subtruncated vertically, but rounding abruptly into the dorsal and ventral borders above and below; beaks not raised above the dorsal margin, and very inconspicuous, their position being indicated only externally by the curves of the marks of growth, located about one-third of the length of the valves from the anterior end; surface only showing fine lines of growth. Length, 1.04 in.; height, 0.36 in.; convexity, 0.28 in. Internal casts of this species show the impression of the strong internal ridge, extending directly downwards from the beaks, and gradually dying out below the middle of the valves. These casts also show the impression of a single small tooth in the right valve, just in front of the upper termination of the deep furrow left by the strong internal ridge.
The largest shell collected by the writer slightly exceeds 45 mm. in length.
Horizon awl locality. Mentor beds, Natural Corral, McPherson County, and 5 miles west of Smolan in Saline County.
1894. Leptosolen otterensis Cragin. Am. Geol., vol. XIV, pp. 8, 9, pl. I, fig. 2.
Cragin's description. Shell compressed, elongated, subrectangular, the height contained nearly two and a half times in the length; dorsal and ventral margins nearly parallel back of the beaks, and somewhat convergent anteriorly from them; anterior margin rounded, posterior truncate; beaks at about the anterior third of the length; valves thin, each presenting a broad, low and gently elevated, distally widening fold, which extends from the beak obliquely downward and forward to the anteroventral margin; cast marked with a strong, distally narrowing and shallowing sulcus which radiates from the beak downward and slightly forward, becoming obsolete before it reaches the ventral margin, and indicating a corresponding rib on the inner face of the valve; surface of cast marked with crowded, fine, concentric, and coarser, rather remote and evenly distributed growth lines. Height, 13 mm.; length, 32 mm.
This is probably the shell which Cragin first designated as Leptosolen belviderei (Bull. Washburn Coll. Lab. Nat. Hist., vol. 2, No. 11, p. 76, 1892). Judging from the figure given by Cragin, it bears a very close resemblance to Leptosolen conradi, and may be that species. As, however, the writer has not been able to see the original specimen and has found none in his own collections, it is deemed best to consider the shells as two distinct species.
Horizion and locality. Cragin's specimen was collected from his zone No. 5 of the Blue Cut section, a horizon corresponding to one of the limestone zones, 12, 14, 16, of the Champion Drew section. It does not appear to have been seen elsewhere.
1894. Limopsis subimbricatus Cragin. Ann. Geol., vol. XIV, p. 4, pl. I, figs. 6-8.)
Cragin's description. Shell small, obliquely subrotund, or obliquely rotund quadrilateral, of moderate convexity; beaks placed a little in advance of the middle, small but distinct, giving the dorsal outline of the shell an apiculate aspect; hinge plate ample, but gradually narrowed to strait in the mid-part, where its lower border is gently subangulated at a point a little back of that immediately below the beaks; denticles about twenty-three in number, arranged in divaricate series, median and terminal denticles short and minute, the intermediate larger and elongate denticles for the most part curved or angulated; outer surface of shell smooth, except for a few remote, unevenly distributed, coarse, concentric growth lines, or incipient imbrications; margin entire. Measurements: Height, 19 mm.; length, 19 mm.; breadth, 10 mm.
Horizon and locality. Cragin obtained his specimens from the Champion shell bed of the Champion Draw section.
1895. Linearia, n. sp., Stanton. In Hill, Am. Jour. Sci., vol. L, pp. 214, 216 (not described).
The shell attains a length of at least 30 mm. and a height of about 18 mm. Beak small, a little anterior to the middle; in a shell 27 mm. long it is 15 mm. from the farthest extension of the anterior margin. This shell is 9 mm. thick.
Both anterior and posterior portions of the shell are radially striate, in the former for about one-fifth the area of the shell and for the latter about one-tenth. The striae are stronger near the margin than on the central portion of the shell. In addition, the surface is concentrically striated by fine ridges and depressions. There are about ten concentric striae to a millimeter and not over five radial striae in the same distance.
Horizon and locality. Mentor beds, 5 miles west of Smolan, Kan. Very abundant.
1896. Lithophagus, sp. nov., Stanton. In Hill, Am. Jour. Sci., vol. L, p. 216 (not described).
Only the tubes of this organism have been seen. These are abundant in shells of Gryphaea corrugata, some shells being simply riddled. The tubes are rarely cylindrical. Neither are they commonly straight or perpendicular to the surface. The basal extremities are abruptly rounded and in some cases a little ridge lies across the base. Diameters vary from 1 to 5 mm.
The shells, judging from the size of the tubes, appear to have grown to a larger size than L. oviformis Gabb from the Cretaceous of California, but are not so large as L. ripleyanus Gabb and L. affinis Gabb, both from the Cretaceous of New Jersey.
Horizon and locality. Occurs at all localities where the Gryphaea horizons of the Kiowa shales have been seen.
Mactra antiqua Cragin
1894. Mactra antiqua Cragin. Am. Geol., vol. XIV., p. 9.
Cragin's description. Shell small, triangular, longer than high, of very moderate convexity; upper anterior margin of either valve, in advance of the feebly excavated-beak front, forming nearly a straight line a little shorter than the feebly convex line described by the superoposterior margin; anteumbonal and postumbonal slopes depressed so as to form a broad and shallow radial sulcus, the anterior sulcus separated from the discal surface by a slight angulation; beaks slightly in advance of the middle; their apices turned inward and but little forward; hinge narrow; the anterior V-ehaped cardinal tooth of the left valve short and stout, its sinus shallow; posterior cardinal narrowed above, broad below, the broad lower extremity bearing on its anterior side a short denticle which imperfectly subdivides the cartilage pit. Measurements: Height, 23.5 mm.; length, 27 mm.; breadth, 16 mm.
Horizon and locality. Cragin's specimens came from the basal portion of his zone 3 of the Champion Draw section, corresponding to zones 8 to 10 or 12 of the writer's section. The shell has not been found in the collections of the writer.
I860. Mactra siouxensis Meek and Hayden. Proc. Acad. Nat. Sci. Philadelphia, vol. VIII, p. 179.
1878. Mactra (Cymbophora?) siouxensis Meek. U. S. Geol. Surv. Territories, vol. IX, p. 206, pl. i, figs. 7a, b and c.
1893. Mactra (Cymbophora?) siouxensis Meek. U. S. Geol. Surv. Bull. 102, p. 177 (not described).
Meek's description. Internal cast oval-trigonal, moderately gibbous; anterior border narrowly rounded, posterior subangular at the extremity; base forming a nearly semiovate curve, the most convex part being toward the front; dorsum declining with a slightly convex outline behind the beaks, and distinctly concave just in front of them; beaks prominent, rather gibbous, verynearly central; pallial impression provided with an oval sinus, which appears to be a little narower behind than in the middle, rounded at the anterior extremity, and extending nearly in a horizontal direction forward, about onefourth of the length of the valves. Length, 1.55 in.; height, 1.22 in.; convexity, 0.76 in. The only specimens of this species that I have seen are internal casts and molds of the exterior, the shell itself being dissolved out. Some of these molds show that the surface was marked by moderately distinct lines of growth, and that the escutcheon was lanceolate in form, and bounded on each side by a very obscure ridge, which extended from the back part of the beaks to near the posterior basal extremity.
Horizon and locality. In the "Dakota" sandstone two miles above the mouth of the Big Sioux river. The writer has not seen the shell.
1893. Mactra siouxensis Cragin. Am. Geol., vol. XVI, p. 164 (not described).
The specimens collected consist of molds, both of exterior and interior; no portion of the shell has been seen. There is abundant material for most of the details. The shell appears to have had a triangular ovate shape, uniformly and gently rounded from the hinge line to the rounded angular posterior extremity, and thence gently convex to the anterior portion of the hinge line. Anterior to the beaks the margin of the interior mold is slightly concave. The beaks and umbones appear to have been quite prominent. Except for concentric growth lines, the surface is unomamented. The growth lines are closely placed and inconspicuous except for an occasional prominent one. All are low and parallel to the border of the shell and are sharper and more conspicuous immediately anterior and posterior to the umbones. Escutcheon narrow and bordered on each side by a rounded angular ridge. Lunule scarcely perceptible. The shell was probably thin.
The anterior muscular scar is small, depressed a little, deeper on the inner side, elongated oval vertically. Posterior scar circular, about level with the surface. The pallial sinus deep, tapering finger-shaped; 12 mm. deep on the anterior side in a specimen of which the interior mold is 40 mm. long, 32 mm. high and 14 mm. thick, 8 mm. wide at the beginning, about 5 mm. at the top. An average-sized specimen has the dimensions given; a few specimens are about one-eighth larger. Dentition teleodont and well developed.
This shell appears to be very close to M. siouxensis Meek and Hayden. It is about the same size and shape, the muscle scars are similar, but the shape of the pallial sinus appears to be a little different, being less elongate oval. The anterior portion of M. siouxensis appears to be somewhat more prominent than in this form. The differences do not appear to be more than varietal and may be consequential to ecologic conditions.
Horizon and locality. Occurs in great abundance in the Mentor sandstone about 5 miles west of Smolan, McPherson County, Kansas. Has not been found in the calcareous strata.
1871. Unio (Baphia?) nebraskensis Meek. Hayden's Second Ann. Rept. U. S. Geol. Surv. Territories, p. 303.
1876. Margaritina nebraskensis Meek. U. S. Geol. Surv. Territories, vol. IX, pp. 114, 115, pl. 1, figs. 5a-c.
1893. Margaritina nebraskensis Boyle. U. S. Geol. Surv. Bull. 102, p. 178 (not described).
Meek's description. Shell attaining a medium or larger size, thin, cuneate-subovate; being in the adult very gibbous anteriorly and cuneate behind; anterior side very short and rounded; posterior sloping above obliquely from the end of the hinge to the posterior basal extremity, which is narrowly rounded; basal border sinuous behind the middle, and convex in front of it; cardinal margin rather short and nearly straight, or slightly arched; umbones very gibbous, but depressed, oblique, incurved, and placed near the anterior extremity; posterior umbonal slopes subangular from the beaks obliquely backward and downward to near the middle, beyond which they are continued as broadly round ridges to the posterior basal extremity; below and parallel to these ridges there are also, on the flanks, one or two large, oblique, irregular, rounded plications or undulations that continue on to the sinuous posterior basal margin, to which they sometimes impart a distorted or waved appearance. Surface otherwise smooth, excepting moderately distinct lines of growth, which are strongly undulating in places as they cross the-oblique ridges or plications of the flanks. Length, 4.10 in.; height, 2.36 in.; convexity, 2.07 in,
Meek states that an external ligament is certainly present and he was not able to observe any posterior teeth. One cast showed the impression of a single compressed anterior tooth with orientation parallel to the anterior slope. The anterior muscular scars are deep, but there are no traces of pedal scars above the anterior adductors. There are no traces of the posterior adductors and the pallial line has not been observed. The writer has not seen the species in any of his collections.
Horizon and locality. "Dakota" sandstone, opposite Sioux City on the Missouri river in Nebraska. Associated with Cyrena dakotensis.
Nucula catharina Cragin
1894. Nucula catharina Cragin. Am. Geol., vol. XIV, p. 4.
Cragin's description. Shell small, compressed, triangular, or cuneate-ovate; the entire exterior ornamented with numerous concentric rows of small, closely set, hyphen-like tubercles, with one or two distal, broad, deeply impressed, concentric growth lines, and with delicate radial striae; each tubercle set so that its trend agrees with the direction of the subjacent concentric growth line, and all the tubercles being arranged not only in concentric series, but at the same time in quincunx order, so as to form two set of intersecting, oblique and gently curving rows. Measurements: Height, 10.5 mm.; length, 15 mm.; breadth, 5 mm., in a small specimen. An imperfect larger specimen indicates dimensions at least one and a half times greater.
In none of the specimens was Cragin able to determine the nature of the hinge structure, so that the reference to the genus Nucula must be considered provisional.
Horizon and locality. Cragin obtained his specimens in what are probably zones 8 to 12 of the writer's section.
1876. Ostrea (sp. undt.) Meek. U. S. Geol. Surv. Territories, pp. 12-16, pl. 2, figs. 8a-b.
1890. Ostrea franklini Cragin. Bull. Washburn Coll. Lab. Nat. Hist., vol. II, No. 11, pp. 75, etc. (not described).
1891. Ostrea franklini Cragin. Am. Geol., vol. VII, pp. 26, etc. (not described).
Shell narrowly oblong to oval, upper valve flat or nearly so, and apparently a little more narrow than the lower one. Lower valve shallow, umbo truncated by mark of attachment. In young forms the entire valve is frequently attached, and these young forms are commonly attached to older individuals, so that a group has, the same general appearance as a group of Ostrea congesta from the Niobrara formation.
Shell thin and fragile, surface modified by undulatory growth lines, which are not prominent. The shell is known to have attained a maximum length of 5 cm. and width of 2 3/4 cm.
The shell described by Meek from the Mentor bed is figured by him as small, of rhombic-subovate outline, having a moderately convex lower valve and a flat upper one. The surface of the latter is stated to have small imbricating lines of growth, while internal casts of the latter show obscure concentric undulations crossed by a few oblique, faintly marked radiating ridges. The specimens from the Mentor bed studied by the writer, which are not certainly known to be the same species as the forms studied by Meek, have the upper valve nearly flat and the surface unmodified except by faintly marked growth lines. The lower valve is very shallow and essentially smooth. The shell is thin. The maximum length observed is about 3 1/2 cm. and maximum width 3 cm.
Horizon and locality. The shell is common in the Kiowa shale at the Blue Cut on the Santa Fe railroad, in the Champion Draw section and other sections to the south toward Sun City and in the Bluff Creek Canyon section. It is quite common in the Windom member in McPherson County. The quartzitic Windom on the southwest corner of sec. 16, T. 20 S., R. 6 W., contains many specimens. Specimens which are believed to belong to this species are common in the Mentor bed near Smolan.
1860. Ostrea quadriplicata Shumard. Trans. Acad. Sci., St. Louis, p. 608.
1879. Ostrea quadriplicata White. Eleventh Ann. Rept., U. S. Geol. and Geog. Surv. Terr., pp. 275, 276, pl. 6, fig. 6a; pl. 8, figs. 3a-b.
1900. Ostrea quadriplicata Gould. Am. Geol., vol. XXV, pp. 34, 38 (not described).
The shells are not large and are of somewhat triangular outline.. The largest are about 30 to 35 mm. long and 20 to 25 mm. high. The main body of the left valve is ornamented by many small plications which are crossed by lamellar growth lines. Near the margin of each valve there are four large radiating plications which are produced beyond the edge of the valve. On the right valve the small plications are wanting. The specimens occur only as molds of the interior and exterior.
Horizon and locality. Specimens of molds of this shell are extremely common in the Mentor bed to the west of Smolan, in Saline County, and at the Natural Corral in McPherson County. Elsewhere it is rare. It has not been seen in the Kiowa shales or associated strata. It occurs commonly in the Washita formation of Texas, Oklahoma and New Mexico.
1804. Vola fredericksburgensis Cragin. Colorado Coll. Studies, Fifth Ann. Publication, p. 52.
This species resembles P. texanus in general appearance and apparently is frequently mistaken for that species. It differs in having a more triangular form, and in its ornamentation. The ribs are narrower and more angular on their summits. The ribs are of three kinds--a large set which are separated from each other by either two or three smaller ones; if three, one of the three is very small and is situated near the side of a rib of the largest kind. Other ornamentation consists of small concentric stria. Beak strongly incurved over the hinge area. No part of the flat valve has been seen. The best-preserved specimen is 25 mm. long, 23 mm. wide.
Horizon and locality. Champion shell bed, Champion Draw, BeIvidere, Kan.
Pecten texanus Roemer
1849. Pecten aequicostatus Lamarck. Texas, F. Roemer, Bonn, pp. 398, 399.
1862. P. texanus F. Roemer. Kreidebildung von Texas, Bonn, p. 65, pl. VIII, figs. 3a-b.
The material referred to this species consists of fragments which hae the ornamentation characteristic of P. texanus, the ribs being flat or gently rounded on top, the summits wide and every third rib being somewhat higher than the two intermediate.
Horizon and locality. Fragments occur rarely in the Champion shell bed at the Champion Draw locality, Belvidere, Kan.
1857. Solen? dakotensis Meek and Hayden. Proceedings Philadelphia Acad. Nat. Sci., vol. IX, p. 242.
1860. Pharella? dakotensis Meek and Hayden. Proceedings Philadelphia Acad. Nat. Sci., vol. XII, p. 425.
1861. Pharella? dakotensis Gabb. Synopsis Mollusks Cretaceous, p. 164.
1864. Pharella? dakotensis Meek. Smithsonian Check-list Cretaceous Fossils, p. 15.
1876. Pharella? dakotensis Meek. U. S. Geol. Surv. Territories, vol. IX, pp. 251, 252, pl. I, fig. 3.
1893. Pharella? dakotensis Boyle. U. S. Geol. Surv. Bull, 102, p. 229 (not described).
Meek's description. Shell elongated and narrow, rather compressed; dorsal and ventral margins nearly straight and parallel; posterior extremity very narrowly rounded, and apparently only moderately gaping; beaks scarcely distinct from the dorsal margin, and located nearly or quite centrally. Surface of cast retaining faint traces of concentric marks of growth; cardinal margin of cast showing a very obscure sulcus along its entire length, both before and behind the beaks. Length, about 1.55 in.; height, 0.35 in.; convexity, 030 in.
Meek's only specimen was a mold of the interior or exterior; he was not positive which. The specimen consisted of two valves partly open. No markings of muscular or pallial impressions were shown, nor was anything preserved to show the character of the hinge area.
Horizon and locality. "Dakota," sandstones at the mouth of the Vermilion river, Nebraska.
1890. Pholadomya sancta-sabae Cragin. Bull. Washburn Coll. Lab. Nat. Hist., vol. II, No. 11, p. 76.
Shell thin, anterior portion about one-third as long as posterior, surface ornamented by radial striae and concentric line,s, the former becoming obsolete on the posterior portion of the shell and stopping abruptly about 10 mm. from the anterior margin. The posterior margin is nearly smooth; the anterior has a wrinkled surface. The middle, portion of the shell is nodular, due to the crossing of, the two sets of ornamentation; the ribs or the stria have sharp or abruptly rounded summits, while the separating depressions are quite uniformly concave from the apex of one rib to that adjacent. Beak closely incurved and turned forward'. A small lunule and escutcheon appear to be present. Dentition not determined. Dimensions of the largest specimen: Length, 37 mm.; height, 30 mm.; thickness of the right valve, 15 mm.; left valve not seen.
This shell is doubtfully referred to the genus Pholadomya, as the dentition has not been seen. It appears to differ from other described species in the absence of radial striae over the anterior portion of the shell. It resembles P. sancta-sabae, but differs in the smoothness of the anterior slopes.
Horizon and locality. Champion shell bed, Champion Draw. Extremely abundant in the Mentor beds at the Natural Corral and 5 miles west of Smolan. Also occurs in zone 17 at Champion Draw.
Pinna comancheana Cragin
1894. Pinna comancheana Cragin. Am. Geol., vol. XIV, p. 3.
Cragin's description. Shell large, thin; anteriorly inflated and subcircular in cross section, becoming more compressed and with exteriorly concave upper slopes posteriorly; not, or only very obtusely, angulated along the median line; increase in height with distance from beak more rapid than in P. lakesi White; decussately ornamented with rather remote radial costellae, and somewhat less conspicuously raised remote concentric lines, there being about nine of the radial costellae on the concave slope. The shell attains a length of at least eight or nine inches.
The writer has seen no specimen of this species and so knows no more of its characters than are given in the description of Cragin.
Horizon and locality. According to Cragin, this shell is common in the Fredericksburg of Kansas, Texas and New Mexico. Cragin's Kansas specimens were derived from the Champion shell bed at Belvidere. Whether the Kansas forms are the same as those from Texas has not been confirmed.
1894. Plicatula senescens Cragin. Am. Geol., vol. XIV, p. 2, pl. I, figs. 17, 18.
Cragin's description. Shell quite small, compressed, inequivalved, obliquely subpyriform or inequilaterally rounded-triangular beaks depressed and indistinct, that of the right valve subtruncate by the scar of adnation; valves ornamented with numerous punctations and short, radially disposed, punctiform wrinkles, so arranged that the intervening elevations do not constitute distinct, continuous, radial, riblike plicules such as are seen in most species of this genus, but rather faintly suggest them; margins of valve thickened, that of the left valve forming a broad, distinctly elevated, concentrically laminated border in marked contrast with the discal structure; right valve moderately convex, and left flattish or slightly concave. Measurements: Height, 11 mm.; length, 19 mm.; breadth, 4.5 mm.
The writer has not seen this shell.
Horizon and locality. Cragin's three specimens were collected from his zone 3, which corresponds to zone 12 to 14 of the writer's Champion Draw section.
1852. Cardium hillanum Roemer (Sowerby). Kreidebildung von Texas, Bonn, p. 49, taf. VI, fig. 12.
1857. Cardium (Protocardia) texanum Conrad. Rept. U. S. and Mexican Boundary Survey, p. 160, pl. VI, figs. 6a-c.
1871. Cardium (Protocardia) salinaenses Meek. Hayden's Second Rept. Geol. Surv. Territories, p. 174, pl. II, figs. 13a-c.
1890. Cardium hillanum? Cragin. Bull. Washburn Coll. Lab. Nat. Hist., vol. 2, No. 11, p. 81 (not described).
1896. Protocardia texana Cragin. Am. Geol., vol. XVI, p. 164 (not described).
1896. Cardium (Protocardia) texanum Stanton. In Hill; Am. Jour. Sci, vol. L, p. 218 (not described).
1900. Protocardia texana Stanton. In Gould, Am. Geol., vol. XXV, p. 36 (not described).
Large shells of this species are quite common in the Mentor beds at nearly all localities where they contain fossils. The shells from the Kiowa shale are smaller and not so common. It is quite probable that the forms described by Meek as Cardium salinaensis were young shells.
Conrad's description. Cordate, subquadrate, obliquely truncated posteriorly, umbo slightly oblique, submedial; disk concentrically ribbed; ribs large and prominent, rounded, laterally abrupt, fine and close on the umbo; postumbonal area with about 17 tuberculated radiating lines.
For completeness, Meek's description of Cardium salinaensis is also given:
"Shell small, nearly orbicular, very slightly longer than high, rather gibbous; pallial margin forming a semicircular curve; anterior margin rounded, the most prominent part being at or a little above the middle, while below this it usually rounds off somewhat obliquely into the base; posterior margin broader, and sometimes slightly subtruncated, or merely broadly rounded; beaks rather depressed, convex, incurved, slightly in advance of the middle; dorsal outline sloping more abruptly in front than behind; posterior umbonal slopes not prominent. Surface ornamented on the sides and front by comparatively rather large, rounded, very regular concentric costae, separated by smaller, furrows; while sixteen to twenty smaller radiating costae, roughened by very little vaulted prominences, formed by the marks of growth, occupy the posterior region of each valve. Height, 0.66 in.; length, 0.68 in.; convexity. about 0.49 in."
The young shells are elliptical in cross section. With age they tend to become more globose. There are about seventeen of the radial ribs, but there is a variation of two to three on each side of this average. The ribs are rounded; the separating depressions are V-shaped. Laminated lines of growth cross the ribs, giving the nodular appearance described by Conrad. The concentric ribs increase in number and strength with age. Their summits are gently rounded, but the sides are nearly vertical, so that the separating depressions are narrowly V-shaped with the upper portions of the V nearly parallel. The specimens from the Mentor sandstone reach dimensions as follows: Length, 47 mm.; height, 50 mm.; thickness, 35 mm. The specimens from the Belvidere formation are about half as large.
Horizon and locality. Extremely abundant and large in the Mentor sandstone at the Natural Corral; less so at the other localities. Occasional small specimens--considered young shells--occur in the limestone zones of the Kiowa shales in nearly every exposure. Gould obtained the species in the Spring Creek shales.
1894. Avicula belviderensis Cragin. Am. Geol., vol. XIV, p. 2.
Cragin's description. Shell strongly ineqivalve, smooth, obliquely purse-shaped, larger than that of A. subgibbosa M. & H., as figured in Meek's "Cretaceous Invertebrate" (Plate 28, fig. 12), to which it bears considerable general resemblance, differing from it apparently in having a longer hinge line, a relatively larger and more prominent anterior and larger posterior ear; anterior ear abruptly compressed, marked off by a distinct but shallow sulcus, and marked with one or two inferomarginal folds; posterior ear continuous with the gently concave posterior slope of the shell; left valve strongly and rather narrowly arched from front to rear, much more convex than the right, its beak also more elevated above the hinge line than that of the latter; (?) hinge line as long as or longer than the shell.
A very good specimen collected by the writer shows that the hinge line is the greatest width of the shell, and in this specimen this dimension is 37 mm. Length along the axis from the beak to margin, 42 mm., depth of right valve, 6 mm. On the right valve, the only one the, writer has seen, the axial portion of the shell is quite convex, and the surface with slightly decreased convexity continues to the margin of the anterior ear. The convexity, abruptly ends posterior to the axis, giving place to a nearly flat or even slightly concave surface over the large posterior ear. The shell resembles P. salinaensis, but appears to have a narrower axial portion, is not so deep, and the anterior ear appears to be better developed.
Horizon and locality. Champion shell beds, Champion Draw. Cragin obtained it from the Cyprimeria kiowana horizons.
1879. Pteria (Oxytoma) salinaensis White. Proc. U. S. Nat. Mus., vol. 2, pt. 2, pp. 296, 297, pl. 5, figs. 1, 2; Smithson. Misc. Coll., vol. 19.
1883. Pteria (Oxytoma) salinaensis White. Twelfth Ann. Rept. U. S. Geol. Surv., pt. 1, pp. 15, 16, pl. 16, figs. 2a-b.
1893. Pteria (Oxytoma) salinaensis Boyle. U. S. Geol. Burvey, Bull. 102, p. 243 (not described).
White's description. Shell rather large for a Cretaceous Pteria; the body, exclusive of the wings, obliquely subovate, broad at the base, moderately gibbous, distinctly but not very greatly inequivalve; the left valve, as usual, more convex than the right and its beak more prominent; the convexity of the valves somewhat uniform, but increasing toward the umbonal region in each, where it is greatest; anterior wing moderately large, defined from the body of the shell by being laterally compressed, but not by any distinct auricular furrow; the byssal sinus under the anterior wing of the right valve having the usual size and shape common to Oxytoma; posterior wing not proportionately large, and not distinctly defined from the body of the shell except by a somewhat gradual lateral compression; its posterior angle not greatly produced; hinge line less than the axial length of the shell; posterior scars not distinct; anterior adductor scars distinct and deep for a shell of this genus, placed immediately in front of the beaks, that of the left valve being, more distinct than the other. The shell is know [sic.?] to have reached an axial length or more than 60 millimeters, a transverse width near its base of at least 50 millimeters, and a thickness of about 25 millimeters when both valves were in natural position.
The surface of this shell, except for growth lines, is smooth. The growth lines are quite marked about the margin of the shell, the larger ones being separated by others of somewhat smaller size.
The shell resembles Pteria belviderensis, and the two forms may be identical. It appears to differ from that shell in the characters given in the description of the latter.
Horizon and locality. White's specimens were collected in Saline County; those of the writer came from the Mentor bed 5 miles west of Smolan, in that county, and the Natural Corral in McPherson County. Not common.
1889. Remondia ferresii Cragin. Bull. Washburn Coll. Lab. Nat. Hist., vol. 2, No. 19.
1894. Remondia ferrisi Cragin. Am. Geol., vol. XIV, p. 6, pl. I, fig. 1.
Cragin's description with corrections of 1894. Shell compressed, subquadrate or subquinquelateral, closed at the extremities; beaks antero-central, the length, of the shell being related to the distance between the anterior extremity and a point opposite the beaks in the ration of 7:3; dorsal margin slightly concave, both anterior and posterior to the beaks; anterior margin rounded, posterodorsal and posteroventral angles produced--the former reaching furtherest posteriorly--and rounded; to the latter extends a rather low but well-marked umbonal ridge; a slight concavity in the surface above the umbonal ridge produces a rather marked concavity of the posterior margin of the shell; ventral margin nearly straight (slightly concave) anterior to the posteroventral angle. Surface irregularly marked by lines of growth, of which two, in the type specimen, are much more pronounced than the others. Interior unknown. Length, 1.02 in.; breadth (approximately), 022 in.; height, 0.65 in.
Horizon and locality. The type and only known specimen of this shell, a right valve, was collected from zone 3 of Cragin's Champion Draw section, corresponding to zones 8 to 12 or 14 of the writer's section.
1894. Roudaria quadrans Cragin. Am. Geol., vol. XIV, p. 7, pl. I, figs. 14, 15.
Cragin's description. Shell small, short, strongly elevated, triangular, the discs of moderate convexity; beaks situated considerably in advance of the middle, elevated, somewhat compressed on the anterior part and strongly so on the posterior, curved inward and downward and directed somewhat forward; no distinctly limited lunule; anterior and discal slopes flattish-convex, separated from each other by a broadly rounded, scarcely appreciable angulation, their outer surface marked only by ordinary, unequal, concentric growth lines; posterior slope (about one-fourth of the valve) strongly flattened, separated from the discal slope by an abruptly rounded angulation, and ornamented by numerous linear radial costellae separated by grooves of about their own width; Measurements: Height, 50 mm.; breadth, 36 mm.; in the largest specimen. Most of the other specimens before me are relatively shorter, and some of them much so.
Horizon and locality. Cragin collected his specimens at Champion Draw from his zone 3, chiefly near its basal portion. This corresponds to about zone 8 of the writer's section. The writer did not find any specimens of this form.
Shell thin, largest specimen 62 mm. long, 22 mm. high. Shape very elongate-elliptical, slightly broader posteriorly. Beak small, not prominent, 22 mm. from the anterior end of the shell, whose dimensions are given. The internal rib about 2 mm. wide at the upper end, narrowing a little below; at least 12 mm. long, directed transversely in upper half, becoming parallel to the length of the shell in the lower portion. Pallial line parallel to the ventral margin and about one-fourth to one-fifth the width of the shell distant therefrom through the anterior two-thirds of the shell. On the posterior portion of the shell the pallial sinus divides the mantle scar into two acute salients. The surface is ornamented with fine lines of growth.
Horizon and locality. Quite common as fragments in the Mentor beds about 5 miles west of Smolan, Saline County, but not seen elsewhere.
1894. Tapes belviderensis Cragin. Am. Geol., vol. XIV, p. 7, 8, pl. I, figs. 12, 13.
Cragin's description. Shell of medium size, ovate, or in elevated specimens triangular-ovate, the superior outline excavated in advance of the beaks; valves of moderate convexity, rather thin, beaks placed at less than one-third of the length from the anterior extremity, only moderately prominent (their summits rising, in adult specimens, about two millimeters above the cardinal teeth); hinge of moderate size; the three divergent cardinal teeth separated by clefts of subequal amplitude, but very deep and abruptly excavated in the case of the anterior cleft, and less so in the posterior; anterior cardinal tooth small; second tooth larger and compressed, but not sharply so; third large, broad, flattish-topped and feebly channeled or bifid; posterior lateral tooth rather large and long; surface marked with ordinary concentric growth lines, of which a few, not regularly spaced, are usually much stronger than the rest.
Cragin gives the dimensions of 45 mm. for the height, 49 mm. for the length, and a thickness of 22 mm. for an elevated example.
The shells exhibit considerable variation in shape, one from the higher beds of the Champion Draw section being more elongate than those below.
Horizon and locality. Cragin obtained his specimens from zones 3 and 4 of his Champion Draw section. The writer's collections were obtained from the Champion shell bed and from zones 8 to 14 of the Champion Draw section and equivalent horizons to the west of Sun City. Poorly preserved specimens referred to this species were collected in zone 2 to the Champion Draw section.
1871. Tellina subscitula Meek. Hayden's Second Ann. Rept, U. S. Geol. Surv., Territories, p. 310.
1876. Tellina (Ene?) subscitula Meek. U. S. Geol. Surv., Territories, pp. 195, 196.
1893. Tellina (Ene?) subscitula Boyle. U. S. Geol. Surv. Bull. 102, p. 176 (not described).
Meek's description. Shell small, elliptic-subovate, much compressed; pallial margin forming a regular semielliptic curve; extremities narrowly rounded, the posterior being a little shorter and faintly subtruncated, with a very obscure flexure, and most narrowly rounded below; dorsal outline sloping gently in both directions from the beaks, the posterior slope being a little convex in outline, and the anterior nearly straight above; beak depressed, compressed, and placed a little behind the middle; muscular impressions moderately distinct, the posterior one being broader than the other; pallial sinus very deep, or extending slightly beyond the middle, nearly horizontal, and rather broadly rounded. Surface with only fine lines of growth. Length, 0.84 in.; height, 0.47 in.; convexity, about 0.15 in.
Meek states that this shell is very like T. scitula from the Upper Cretaceous, but is proportionately more depressed, has a different pallial sinus, and appears to have less strongly defined lines of growth.
Horizon and locality. Meek's specimens came from Mentor beds, 12 miles southwest of Salina.
1867. Trigonia emoryi Conrad. Rept. U. S. and Mex. Bound. Surv., vol. I, pt. 2, p. 148, pl. 8, figs. 2a-c.
1889. Trigonia emoryi Cragin. Bull. Washburn Coll. Lab. Nat. Hist., vol. 2, No. 6, p. 75 (not described).
1895. Trigonia emoryi Cragin. Am. Geol., vol. XVI, p. 164 (not described).
1895. Trigonia emoryi Stonton. In Hill, Am. Jour. Sci., vol. L, pp. 214, 216 (not described).
1897. Trigonia emoryi Vaughan. Am. Jour. Sci., vol. IV, p. 48 (not described).
1900. Trigonia emoryi Gould. Am. Geol., vol. XXV, p. 37 (not described).
The shells are triangular-avate in outline, with the posterior extremity narrowly rounded and somewhat compressed. The ribs which ornament the surface meet the anterior margin nearly at right angles and are there widest, highest and farthest apart. The largest ribs are about 2 mm. wide at the base and about 1 1/2 mm. high. The separating spaces are gently concave and from 1/2 to 1 mm. wider than the ribs. The summits of the ribs are ornamented by elliptical nodules, which are slightly compressed transversely to the ribs. On any limited portion of the shell the nodules are of approximately equal development. The ribs converge posteriorly and become lower and smaller as they approach the margin of the escutcheon, where they are reduced almost to striae. The escutcheon is bounded by a sulcus, of which the transverse profile is triangular with the bounding sides, convex inward. The sulcus is margined on each side by a low rounded ridge. After crossing the sulcus the ribs change direction, trending from the beaks, thence curving upward almost to the beaks. They also increase in size and reach the posterior (in this case upper) margin at angles which are acute downward.
The beaks appear to be directed posteriorly, but the extreme tips apparently have anterior direction. The muscle scar (posterior) is very prominent, nearly circular in outline, placed in a shallow depression and margined upward by a convex, quarter-moon-shaped ridge. Hinge line sharply striated with about ten teeth.
The largest shells are about 45 mm. high, 50 mm. long, and at least 25 mm. thick.
Horizon and locality. Extremely abundant in the red sandstones of the Mentor beds, particularly about 5 miles west of Smolan, Saline County. Not uncommon in the Mentor beds at the Natural Corral, but has been seen in nearly every place where the Mentor strata show float or exposures. Not uncommon in every limestone bed of the Kiowa shales. To the south it occurs in the Washita formation of New Mexico, Oklahoma and Texas.
1876. Trigonarca (Brevicara?) salinaensis Meek. U. S. Geol. Surv, Territories, vol. IX, pp. 92, 93, pl. 2, figs. 1a-c.
1893, Trigonarca (Brevicara?) salinaensis Boyle. U. S. Geol. Surv. Bull. 102, p. 289 (not described).
Meek's description. Shell small, suborbicular, gibbous;, rounded-sub-truncate anteriorly, semiovate below, and apparently slightly truncated behind; hinge line declining rather distinctly from the beaks; hinge denticles comparatively rather strong, about eight of them being seen on what appears to be the anterior side of the beaks of one valve; muscular impressions very faintly marked; beaks prominent, central, very gibbous, and incurved without visible obliquity. Hinge area and surface markings unknown. Length, about 026 in.; height, 0.23 in.; convexity, 0.23 in.
The denticulate area on the posterior side of the hinge area is about 5 mm. long and contains about five denticles to two millimeters. On the posterior end of the hinge line the denticulated area is not more than half so long. The shell is much smaller than T. siouxensis, and it is quite improbable that it is the young of that species. The specimens are wholly in the form of internal molds.
Horizon and locality. Mentor beds, rather rare. The writer's specimens came from 5 miles west of Smolan, Saline County, and Meek's specimens from twelve miles southwest of Salina.
1854. Pectunculus siouxensis Hall and Meek. Members Am. Acad. Arts and Sci., vol. V, p. 384.
1861. Pectunculus siouxensis Gabb. Synopsis Mollusks Cretaceous Formation, p. 103.
1884. Axinara siouxensis Meek. Smithsonian Check-list Cretaceous Invertebrate Fossils, North America, p. 8.
1876. Trigonarca (Brevicara?) siouxensis Meek. U. S. Geol..Surv., Territories, vol. IX, p. 92, pl. 1, fig. 6.
1883. Trigonarca (Brevicara?) siouxensis Boyle. U. S. Geol. 8urv. Bull. 102, p. 289 (not described).
Meek's description. Shell (as inferred from internal casts) subquadrangular, gibbous, a little longer than high; basal margin rather straight; anterior outline vertically subtruncated, but convex along the middle, and rounding rather abruptly into the base, as well as to the hinge above; posterior side obliquely truncated above and narrowly rounded below; hinge margin a little straightened along the middle, but curving downward at each end; hinge denticles small and rather crowded; beaks nearly central, and slightly or not at all oblique. Cardinal area and surface markings unknown. Length, about 0.93 in.; height, 0.84 in. '
The writer has not seen this species.
Horizon and locality. Meek's specimens came from the Dakota sandstone from exposures at the mouth of the Big Sioux river in South Dakota.
1872. Yoldia microdonta Meek. Hayden's Sixth Ann. Rept. U. S. Geol. Surv., Territories, p. 304.
1876. Yoldia microdonta Meek. U. S. Geol. Surv., Territories, vol. IX, p. 109, pl. 2, fig. 2.
189S. Yoldia microdonta Boyle. U. S. Geol. Surv. Bull. 102, p. 315 (not described).
Meek's description. Shell small, longitudinally subovate; anterior margin more or less narrowly rounded, being generally more prominent above the middle; pallial margin forming a semiovate curve, being more prominent before than behind the middle, and curving up gradually and obliquely at both ends; posterior side compressed, and with its margin narrowly rounded, or almost subangular at its connection with the hinge above; cardinal margin sloping gradually from the beaks, the posterior slope being very slightly concave in outline, and the anterior nearly straight; beaks rather depressed and placed a little in advance of the middle; hinge line equaling about three-fourths the entire length,, and provided with very fine, regular, pointed denticles, of which 26 may be counted behind, and 20 before the beaks, in each valve. Muscular and pallial impressions very obscure, and not visible on internal casts. Surface not well known. Length, 0.50 in.; height, 028 in.; convexity, 0.14 in.
Horizon and locality. This shell is extremely rare. Of the writer's specimens one came from the Mentor beds at the locality 5 miles west of Smolan, Saline County, and the other from the Natural Corral, McPherson County. Meek's specimen came from the same strata at a locality 12 miles southwest of Salina.
1890. Ammonites pedernalis Cragin. Bull. Washburn Coll. Lab. Nat. Hist., vol. 2, No. 11, p. 75 (not described).
1890. Ammonites belviderei Cragin. Idem., p. 76 (not described).
1891. Ammonites belviderei Cragin. Idem., p. 27 (not described).
1891. Ammonites belviderei Cragin. Idem., p. 27 (not described).
1894. Ammonites belviderei Cragin. Am. Geol., vol. XIV, pl. I, figs. 3-5 (no description).
1895. Sphenodiscus sp. Stanton. In Hill, Am. Jour. Sci., vol. L, p. 217 (not described).
1899. Buchiceras (Sphenodiscus) belviderensis Cragin. Colorado Coll. Studies, vol. VII, pp. 27-29.
1899. Buchiceras (Sphenodiscus) belviderensis var. uddeni. Idem., p. 30, pl. I, figs. 3, 4.
1899. Buchiceras (Sphenodiscus) belviderensis var. mentorensis. Idem., p. 31, pl. I, figs. 6, 7.
1899. Buchiceras (Sphenodiscus) belviderensis var. mons-comancheanus. Idem., p. 29, pl. I, fig. 5.
Cragin's description. "Shell of medium size, flattish-lenticular, the venter (periphery) truncate, narrowly so on the younger whorls, broadly and less sharply and less evenly so on the oldest one, particularly on the body chamber; body chamber, occupying three-eighths to one-half of a volution; umbilicus narrow, the greater part of the height of the second whorl being embraced within one-third to one-half of that of the body chamber; suture "ceratitic," much like that of Sphenodiscus pedernalis von Buch, the part corresponding to the outer saddle of (strictly so-called) Buchiceras being divided into five saddles by means of four leaves, of which the very unequal outer two are much smaller than the subequal inner two; all of the saddles of the suture rounded to flattish, or, in case of some of the inner ones, emarginate at fundus, some symmetrically, some obliquely so, and all much broader than the leaves, excepting the next to the outermost of those formed by the lobing of the outer buchiceran saddle; the leaves little cleft at the summit; ornamentation of the shell consisting usually of at least two revolving series of low tubercles on either side; one consisting of few tubercles, one or two of the newer of which sometimes become more prominent than any other tubercles on the shell; the other, presented ventrally on the ventrolateral margin, and consisting of numerous tubercles so compressed as to trend with that margin, and so arranged that those of the right alternate with those of the left margin, half (consisting of every other one) of these tubercles constituting the termini of broadly and feeble accentuated lateral ribs, which are confined to the outer part of the flank, and at whose inner ends (one at the end of each) the very low and diffuse tubercles of a third revolving series may be developed."
Cragin states that this is the commonest member of its genus in the Comanche Peak limestone of Texas, while it is the only representative of the genus in the strata of the Kansas Comanchean. He distinguishes five varieties; that from the Champion shell bed he calls mons-comancheanus. This form is said to have its--
"Suture relatively complex for this species having even the smaller leaves more or less cut at the summit, usually with two or three simple, obtuse lobules, and the larger leaves cleft into a larger number (4-6) of processes, which are either simple and short (toothlike) to somewhat larger (subdigitiform), or show a tendency to secondary toothing, or two of the processes being expanded at the extremity and abruptly truncated or notched. Of the saddles centripetally succeeding the five secondary saddles, the first three are simple and subrotund (the first one a little compressed), with simple to truncate extremity, the next two (respectively, just outside of and opposite the circumumbilical tubercles) are broader than deep and strongly emarginate or bilobate, being parted into two lobes by a small and short clavate leaflet."
The variety uddeni is stated to have the--
"Suture relatively complex, the primary lateral and the larger secondary lateral and auxiliary leaves little different from those of var. mons-comancheanus, the leaves and saddles interior to the secondary ones being as follows: First and second lateral leaves irregularly and obtusely dentate, inclosing a large, simple, subrotund saddle--these followed in succession by a deeply emarginate saddle; an intermediate-sized, asymmetrical, feebly denticulate leaf; three simple, subrotund, subequal saddles, parted by two small, simple, clavate leaves; a small emarginate leaf; a smail deeply emarginate saddle; a narrow emarginate leaf; a broad emarginate saddle (this is the line of the series of circum-umbilical tubercles); and finally, a small leaf and saddle,, both emarginate."
The variety mentorensis is said to be "distinguished by having the two simple truncate saddles second and third exterior to that which is the course of the circum-umbilical tubercles, remarkable broad and shallow."
It is questionable what emphasis should be placed, on the differences pointed out by Cragin and to what extent they really exist as persistent characteristics. Considering the fragmentary and scanty material which has been collected from the Kansas Comanchean of this shell, it follows that there is considerable basis for error.
Horizon and locality. The writer collected no specimens of this species in the Belvidere region. It is said to be present in the Champion shell bed and higher strata. The variety differentiated as uddeni was found in the Windom member near Lindsborg, Kan. The specimens collected by the writer were obtained from the Mentor beds at the locality five miles west of Smolan, Kan.
1858. Ammonites belknapi Marcou. Geol. North America, p. 34, pl. 2, figs. 1a, 1b.
Marcou's description. Shell oval compressed, subdiscoidal, sharp and strongly carinated. The sides are ornamented with large, rounded ribs, widening toward the back, slightly flexuous; they usually occupy the entire breadth of the sides, but some irregularly distributed stop at two-thirds the distance, beginning at the back. Although this specimen has lost its central portion, it is easy to see that the spire increases very rapidly and that the whorls are compressed and two-thirds concealed by each other. The last whorl is almost as large as half the diameter of the entire shell. In regard to the keel, the ribs do not correspond, but alternate. . . . Septa with four trifid lateral lobes widely separate and very distinct upon this specimen.
Fragments of one side of a large cephalopod with large coarse ribs like those of S. belknapi are not uncommon in the Kiowa of the Champion Draw section. A fragment of a whorl is 12 cm. wide and there are fragments indicating a larger size. No septal markings are preserved.
Horizon, and locality. Five fragments of specimens have been collected in zones 8, 12 and 14 of the Champion Draw section. One specimen was collected at the Blue Cut section on the Santa Fe railroad. The species is quite common in the Washita formation of Texas (Duck Creek beds).
Only fragments of this shell are known. It attains a large size, as an impression of a whorl at least 9 cm. across is known. Shell with a large keel, which is gullied at its margin with the main body of the shell. This keel is 13 mm. wide in a shell where the whorl with the keel is 6 cm. wide. Ribs poorly S-shaped, without nodes of any kind, of imbricated aspect, swollen at the outer ends, abrupt toward the aperture and gently sloping in the opposite direction. On the inner side of a whorl they bend sharply forward for about one-fifth their length, thence bend backward so as to cross the axis of the whorl at about right angles and bend forward toward the aperture a little at the outer ends. The tops of the ribs are gently rounded.
This shell may be the one identified by Cragin under the name of Ammonites belviderei (Washburn Coll. Lab. Nat. Hist., vol. 2, No. 1, 1890, p. 76). It resembles S. trinitensis Gabb from the Fredericksburg of Texas, but differs in the summits of the ribs, being less sharp and less symmetrical. The keel in that species is also not known to be developed to the extent that it is in this specimen.
Horizon and locality. Champion shell bed, Champion Draw, near Belvidere, Kan., and in the higher Kiowa at Blue Cut mound on the Santa Fe railroad to the west of Belvidere.
1853. Ammonites acuto-carthatus Shumard. Exploration Red River, La., Paleontology, p. 197, pl. 1, fig. 8.
1858. Ammonites peruvianus Marcou. Geol. North America, 34, 35, pl. 5, figs. 1, 1a, 1b.
1890. Ammonites acutocarinatus Cragin. Bull. Washburn Coll. Lab. Nat. Hist., vol. II, No. 11, pp. 75, 76 (not described).
1891. Ammonites acutocarinatus Cragin. Am. Geol., vol. VII, pp. 26, 27 (not described).
1892. Schloenbachia peruvianus Cragin. Fourth Ann. Rept., Texas Geol. Surv., pp. 242, 243.
1895. Schloenbachia peruvianus Stanton. In Hill, Am. Jour. Sci., vol. L, p. 217 (not described).
Ammonites peruvianus was described by Leopold von Buch from fragments collected by Alexander von Humboldt on the Rio Maranon, one of the tributaries of the upper Amazon. The writer has not seen either the descriptions or illustrations of von Buch's specimen and so cannot affirm that the shell of the southwestern part of the United States identified as Ammonites peruvianus is the species of von Buch. In stating this identity the writer follows Cragin, Marcou and Stanton. Shumard (Marcy's Exploration, of the Red River) described the shell as Ammonites acuto-carthatus. His description fits fairly well, but his illustration resembles a brachiopod quite as much as it does a cephalopod. The description is as follows, the italicized words being the present writer's:
"Shell much compressed, sharply carinated, ornamented with from 30 to 34 transverse ribs; ribs simple, distinctly elevated, flexuous, commencing narrow at the umbilicus and widening to within a short distance of the dorsal (ventral) border, where they are again somewhat contracted; dorsal (ventral) carina prominent, sharp, smooth, marked on each side by a shallow depression; aperture elongate-cordate, lateral septa trilobate."
In young to half-grown shells the ribs have flat or gently rounded summits and are considerably wider than the separating depressions. In mature to old shells the last half or two-thirds of the outer whorl has the ribs considerably higher and more abruptly rounded, while the separating depressions are about as wide as the ribs. Most of the ribs begin at the umbilicus, but every third to fifth rib arises from one-half to three-fourths inch from the umbilicus through bifurcation of a rib which begins at the umbilicus. A full-grown specimen may have as many as 90 ribs.
Horizon and locality. Only fragments have been collected by the writer from Kansas horizons. These came from the Kiowa shales of the southwest, where it is not uncommon in the Champion shell bed and in zones 8, 10, 12 and 14. It has not been found in the Mentor beds. The shell is common, and in some localities abundant, in the Washita formation of Texas (Kiamitia and Duck Creek beds) and Oklahoma, and it is also quite common in the Fredericksburg formation.
Kansas Geological Survey, Geology
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