Vanderpool's species because of prior use of 

 bispinosa for another species of Cypridea. In ad- 

 dition, as pointed out by Howe and Laurenich 

 (1958, p. 141), C. ventrosa Jones has right valve 

 overlap and the present species can not be a va- 

 riety of it. Several closely related species, charac- 

 terized by pitted and pustulose surface and by a 

 median to postero-median spine have been de- 

 scribed from Asia i.e., C. occollata Lubimova, C. 

 polita Galeeva, C. salva Lubimova, C. solida Ga- 

 leeva, C. stellata Galeeva and C. valida Galeeva 

 all from the Lower Cretaceous of Mongolia (Lu- 

 bimova, 1956, p. 20, 33, 43, 44, 57, 72). All of 

 these differ from the present species in details of 

 shape and ornamentation, but serve as an indica- 

 tion of the general age relations of this kind of 

 Cypridea. 



Occurrence. — DeQueen Limestone, Gypsum 

 Bluff near Murpheesboro, Pike County, Arkansas, 

 and rarely in Glen Rose Formation eight miles 

 south of Weatherford, Texas. 



Cypridea wyomingensis Jones 



Plate 4, Figure 10; Plate 5, Figures la-c 

 Text Figure 4b 



Cypridea tuberculata var. wyomingensis Jones, 



1893, Geol. Mag., Dec. 3, v. 10, p. 386, pi. 15, 



figs. 5a, b; 6a, b. 



White, 1895, U. S. Geol. Survey Bull. 128, p. 62, 

 pi. 11, figs. 5a, b; 6a, b. 

 Cypridea tuberculata var. gypsumensis Vander- 



pool, 1928, Jour. Paleont. v. 2, p. 103, pi. 13, 



figs. 9-12. 

 Cypridea wyomingensis Jones. Peck, 1941, Jour. 



Paleont, v. 15, p. 297, pi. 43, figs. 10-17; 1951, 



Jour. Paleont, v. 25, p. 312, pi. 45, figs. 4-7. 



Loranger, 1951, Bull. Am. Assoc. Petroleum 

 Geologist, v. 35, p. 2363, pi. 2, fig. 22. 



Clark, 1954, West. Canada Sed. Basin, Tulsa, p. 

 293, pi. 2, fig. 22. 



Howe and Laurencich, 1958, Introd. Study Cre- 

 taceous Ostracoda, p. 142, text fig. 

 Cypridea cf. C. wyomingensis Jones. Swartz and 



Swain, 1946, Jour. Paleont v. 20, p. 372, pi. 52, 



figs. 19-22. 



The shell of this species has been thoroughly 

 described in several of the publications cited. It 

 is relatively elongate, subquadrate, with well de- 

 veloped anteroventral hood, beak, furrow and 

 notch; surface is coarsely tuberculate or spinose 

 and coarsely and densely pitted; there is a shal- 

 low, oblique anterodorsal sulcus. 



Remarks. — The authors concur with Howe and 

 Laurencich (1958, p. 142) in referring Vander- 

 pool's specimens to wyomingensis. 



Occurrence. — The species has been found in the 

 Lower Cretaceous Bear River Formation of Wyo- 

 ming, questionably from the Upper Jurassic 

 Schuler Formation of southern Arkansas, and 

 Vanderpool's specimens are from the DeQueen 

 Limestone at Gypsum Bluff, near Murpheesboro, 

 Pike County, Arkansas. 



Cypridea diminuta Vanderpool 



Plate 4, Figure 9; Plate 5, Figures 2a-d 



Text Figure 3b 



CypHdea diminutus Vanderpool, 1928, Jour. Pa- 

 leont, v. 2, p. 103, pi. 13, figs. 7, 8. 



Cypridea diminuta Vanderpool. Peck, 1941, Jour. 

 Paleont, v. 15, p. 298, pi. 44, figs. 29-32; 1951, 

 Jour. Paleont, v. 25, p. 312, pi. 49, fig. 6. 

 Howe and Laurencich, 1958, Introd. Study Cre- 

 taceous Ostracoda, p. 121, text fig. 



Shell small, subquadrate, highest about one- 

 fourth from anterior end; dorsal margin nearly 

 straight, projecting slightly at anterior cardinal 

 angle; cardinal angles obtuse, the anterior larger 

 than the posterior ; ventral margin nearly straight 

 to slightly convex, with small anteroventral notch, 

 converging posteriorly with dorsum; anterior 

 margin broadly rounded, truncate above ; posterior 

 margin with same curvature, but much narrower. 

 Left valve larger than right, overlapping and 

 overreaching along free margins. Valves com- 

 pressed, most convex medially to posteromedially. 



Anteroventral portion of right valve with small 

 narrow submarginal hood, beak, furrow and 

 notch ; corresponding area on left valve consists 

 of a small pit in place of furrow and with hood, 

 beak, and notch reduced or absent. General sur- 

 face very densely pitted in a sievelike pattern, the 

 interspaces only about one-half width of pits; a 

 few small scattered pustules occur on surface. 

 Outer margin of right valve, along venter, bears 

 a row of submarginal, closely spaced, short 

 grooves. 



Hinge of left valve consists of a long faintly 

 crenulate groove at either end of which is a small 

 socketlike depression. Inner lamellae narrow, but 

 details of this and other internal structures ob- 

 scured by recrystallization of shell. 



Length of holotype shell selected here (PI. 4, 



16 



