Maryland Geological Survey 463 



Order TELODESMACEA 



Superfamily CYPRICARDIACEA 

 Family PLEUROPHORIDAE 



Genus CYPRICARDINIA Hall 



Cypricardinia cf. lamellosa Hall 

 Plate LXXVIII, Figs. 6, 7 



Cypricardinia lamellosa Hall, 1859, Nat. Hist. N. Y., Pal., vol. iii, p. 266, pi. 

 xlixa, figs, la, b, c, 1861. 



Description. — " Shell subovoid, gibbous ; umbones slightly elevated ; 

 anterior extremity abruptly rounded and extending little beyond the beak, 

 somewhat contracted on the base anterior to the middle, with an unde- 

 fined depression extending thence nearly to the umbones; posterior slope 

 prominent, with a scarcely defined ridge; cardinal margin compressed, 

 obliquely subtruncated above and rounded towards the base. Surface 

 marked by strong elevated distant lamellae; the surface of each one show- 

 ing under a magnifier, distinct radiating strife, and sometimes another 

 set of striae cancellating the first." Hall, 1859. 



Occurrence. — Helderberg Formation, Keyser Member. Keyser, 

 West Virginia. 



Collection. — U. S. Xational Museum. 



[Maynard.] 



Cypricardinia sublamellosa Hall 



Plate LXXVIII, Fig. 8 



Cypricardinia sublamellosa Hall, 1859, Nat. Hist. N. Y., Pal., vol. iii, p. 267, 

 pi. i, fig. 1, 1861. 



Description. — " Shell transversely elongated ; anterior extremity con- 

 tracted ; umbones very depressed ; posterior slope convex, without a de- 

 fined ridge; extremity somewhat acutely rounded. Surface marked by 

 rounded concentric strife or ridges, which are more prominent on the 

 posterior half of the shell." PTall, 1859. 



