276 Systematic Palkoxtology — Middle Devonian 



Genus CYPRICARDINIA Hall 

 Cypricardinia indknta (Conrad) 



Plate XXXIV, Figs, (i-10 



Cypricardites indenta Courad, 1842, Jour. Acad. Nat. Sci., Phlla., vol. viii, p. 



244, pi. xii, fig. 12. 

 Cypricardinia indenta Hall, 1870, Prelim. Notice Lamellibranchiata 2, p. 83. 



(In part.) 

 Cypricardinia indenta Hall, 1885. Pal. N. Y., vol. v, pt. i, Lamellibranchiata 



ii, p. 485, pi. Ixxix, figs. 6-16, 23; pi. xcvi, fig. 2. 

 Cypricardinia. indenta Keyes, 1891, Johns Hopkins Univ. Circ, vol. xi, p. 29. 

 Cypricardinia indenta Clarke. 1903, N. Y. State Mus., Bull. 65, p. 378. 

 Cypricardinia indenta Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, 



p. 536, fig. 729c. 



Description. — " Shell of lucdinm size, siiltrhoniboid-ovate shape; length 

 more than one-third greater than the height; basal margin nearly straight, 

 slightly sinuate anterior to the middle; posterior extremity abruptly 

 rounded below and obliquely truncate above; anterior end very short, 

 rounded below; cardinal line straight, oblique. Eight valve very convex, 

 often extremely gibbous; left valve usually depressed convex below and 

 posteriorly, becoming moderately gibbous in the umbonal region; beaks 

 nearly anterior, small and appressed, rising but little above the hinge- 

 lino; cincture distinct on the right valve, less marked upon the left one; 

 uiubonal slope rounded and pi-oniinent on the right valve, suliaugular on 

 the left one. Surface marked by extremely tine concentric striae and by 

 unequally distant but somewhat regailar lamellose, imbricating, concentric- 

 undulations; and in well preserved specimens the entire surface is marked 

 by fine striae, which radiate from the apex of the shell." Hall, IScSo. 



Several specimens of this species were collected ; most of which were 

 obtained from the shales on Evitts Creek below Wolfe Mill. They are 

 typical and do not differ in any noticeable respect from those figured from 

 the JIauiilton of Xew York. Hall reported the species from Hardy 

 County, [W.] Virginia (Pal. X. Y., vol. v, pt. 1, Lamellibranchiata ii, j). 

 486). Like a number of the other Pelecypoda found in the ]\Iaryland 

 Hamilton it is a sharply defined species so that there is no uncertainty 

 regarding its identification. Its most striking characters are the shape; 

 the strong, unequally distant, laiucllose concentric undulations; fine 



