306 PALAEONTOLOGY OF NEW-YORK. 



Position and locality. This species occurs in the Utica slate in the Mohawk valley, and 

 in the lower shales of the Hudson-river group at Turin and Pulaski. (State Collection.) 



366. 2. METOPTOMA? RUGOSA (n. i^).). 



Pl. LXXXIII. Figs. 6 a, b, c. 



Elliptical, with the sides straight ; apex elevated, and slightly bent forwards ; posterior 

 extremity broader than the anterior; surface marked by strong concentric undulations, 

 which increase in number on the posterior side. 



Fig. 6 a. View of the upper surface of the shell. 6 b. Lateral view of the same. 

 Fig. 6 c. An enlarged portion of the surface. 



Position and locality. In the subcrystalline calcareous beds, associated with the Hudson- 

 river shales, near Troy. 



239. 2. CARINAROPSIS PATELLIFORMIS. 



Pi.. LXXXIII. Fig3. 7 a, b. 

 Reference Carinaropsii patelHformis, pag. 183, pl. 40, figs. 2 a, b, of this volume. 



This species is perhaps more abundant in the Hudson-river group than in the Trenton 

 limestone, and sometimes attains to a greater size. The smaller specimens appear like an 

 Orbicula ; but the shell is of a different texture, and the constant absence of a second, 

 flatter valve, both here and in the Trenton limestone, confirms me in the opinion already 

 given. 



Fig. 7 a. A large individual of this species. 



Fig. 7 b. Profile view of the same. The elevation of the shell is less than usual, from compression. 



Position and locality. This species occurs in the argillaceous and calcareous parts of the 

 group at Turin and Pulaski, and in the semi-altered shales near Waterford. 



{State Collection.) 



367. 3. CARINAROPSIS ORBICULATUS («.s/).). 



Pl. LXXXIII. Figs. S a, b, c. 



Suborbicular ; apex subcentral, small, slightly inclined ; surface finely striated. 



This species lias the form of Orbicula, but the apex is remarkably elevated, and no flat 

 valve has been observed. It is also different in texture from the known species of Orbicula 

 in the same rock. 



Fig. 8 a. View of a specimen, looking upon the apex. 

 Fig. 8 b. Lateral view of specimen partially distorted. 

 Fig. 8 c. A portion of the surface enlarged. 



Position and locality. In the slates of the Hudson-river group, near Waterford. 



(State Collection.) 



