474 



LAMELLIBRANCHIA TA. 



[CYC.- 



eon ; pallial line simple. Type C. 

 miamiensis. 



coriformis, n. sp. Shell large, having 

 a length in some specimens of three 

 inches, and a height of two inches; 

 larger at the anterior end, and cunei- 

 formly tapering to the posterior point; 

 beaks large, high, pointed and inrolled 

 above the cardinal line ; cardinal line 

 straight from the top of the lunule 

 three-fourths of the length of the shell, 

 the posterior part forming a wing-like 

 appendage of the shell ; escutcheon dis- 



FIG. 805. Gun earn ya coriformis. Right valve, 

 below medium size. 



tinct and well marked; lunule heart- 

 shaped, very large, wide and deep, 

 margins angular; the anterior end of 

 the shell rapidly slopes backward from 

 the lower extremity of the lunule to the 

 basal line ; an obtuse angle is formed 

 at the base of the lunule ((his is better 

 shown in the illustrations by the figure 

 of the right valve than by the anterior 

 view) ; a cincture or furrow, arising at 

 the point of the beaks, and very gradu- 

 ally widening, reaches the basal line 

 anterior to the middle of the shell ; 

 anterior uinbonal ridge very promi- 

 nent ; posterior umbonal slope promi- 

 nent, flattened on the 

 outer face so as to form 

 an obtuse angle toward 

 posterior cardinal wing; 

 basal lin e slightly curved, 

 with a sinus at the cinc- 

 ture surface ; concentric- 

 ally lined. Distin- 

 guished from C. miami- 

 ensis by the remarkably 

 large lunule, better de"- 

 fined cincture, and pos- 

 terior cardinal wing. 

 Found in the Hudson River Group 

 at Cincinnati, Ohio. The specific name 

 is from the heart-shaped lunule. The 

 specimen illustrated is from the col- 

 lection of Charles Faber. 



FIG. 806. Cune- 

 amya corifor- 

 mis. Anterior 

 view, showing 

 lunule. 



FIG. 807. Cuneamya miamiensis. Right valve. 



curta, Whitfield, 1878, Jour. Gin. Soc- 

 Nat, Hist, vol. 1, p. 138, Hud. Riv. Gr. 



elliptica, S. A. Miller, 1881, Jour. Gin. 



Soc. Nat. Hist., vol. 4, p. 317, Hud. 



Riv. Gr. 

 miamiensis, Hall & Whitfield, 1875, Ohio 



Pal., vol. 2, p. 91, Hud. Riv. Gr. 



Fro. 808 Cuneamya miaruiensis. Dorsal view 



neglecta, Meek, 1871, (Sedgwickia neg- 

 lecta,) Proc. Acad. Nat. Sci. Phil., p. 

 325, and Ohio PaX, vol. 1, p. 142, Hud. 

 Riv. Gr. 



parva, S. A. Miller, 1880, Jonr. Cin. Soc. 

 Nat. Hist., vol. 3, p. 316, Hud. Riv. Gr. 



scapha, Hall & Whitfield, 1875, Ohio Pal 



vol. 2, p. 92, Hud. Riv. Gr. 

 CYCLOCONCHA, S. A. Miller, 1874, Cin. Quar. 

 Jour. Sci., vol. 1, p. 231. [Ely. in al- 

 lusion to the nearly circular form of the 

 shell.] Equivalve,"subequilateral, sub- 

 circular, concentrically lined; cardinal 

 teeth near the middle, with a long 

 lateral tooth on each side. Type C. 

 mediocardinalis. 



FIG. 810. Cypricardella 

 bellistriata. 



mediocardinalis, S. A. Miller, 1874, Gin. 

 Quar. Jour. Sci., vol. 1, p. 231, Hud. 

 Riv. Gr. 



CYPRICARDELLA, Hall, 1858, Trans. Alb. 

 Inst., vol. 4, 

 p. 17. [Ety. 

 diminutive of 

 Cypricardia . ] 

 Shell ovate, 

 subelliptica 

 or subquad- 

 rate, closed ; 

 surface con- 

 centrically 

 striated; two 

 cardinal teeth in right valve, one be- 

 neath the beak, triangular, the posterior 

 one more slender, and turned obliquely 

 backward, leaving a triangular pit for 

 the tooth from the other valve ; long, 

 narrow groove in the anterior cardinal 

 margin apparently for a projection 

 from the left valve ; posterior side bev- 

 eled from above, edge thin, ligament 

 external, occupying a deep cavity ; 

 muscular impressions distinct, shal- 

 low; pallial impression simple. Type 

 C. subelliptica. 



bellistriata, Conrad, 1842, (Microdon bel- 

 listriatus,) Jour. Acad. Nat. Sci., vol.8, 

 p. 247, Ham. Gr. 



