264 



of the shell visible only in the most perfectly preserved 

 specimens. 



Found in the black Naples (Gardeaii) shales of the Lake 

 Shore; in the gray Naples (Cashaqua) shales, at Section 1; 

 in the Genesee shales (especially abundant in the lower l)lack 

 bands of Section 1, etc.); and on the Lake Shoi-e; in the 

 Styliolina layer (rare); in the lower Hamilton shales, be- 

 tween nine and twelve feet below the Enerinal limestone, at 

 Section 7 (one specimen); also in the Transition shales, on 



the Lake Shore; and in the Mar- 

 cellus shales, on the Lake Shore 

 (where the species is common). 



LUNULICAIJDIUM OKXATUM. Hall. 



(Fig. 184.) (Pal. N.Y.,Yol. v., Pt. 

 L, p. 437, PL LXXL) 



D is t in g u is h in o- Cliararters. — 

 Large size; broadly obovate out- 

 line; forty-five to sixty regular 

 flattened radiating ])lications, with 

 narrow interspaces, and crossed 

 b}^ closely-arranged, undulating, 

 lamellose. concentric stri;v. 



Found (?| in the lower Genesee shale, at Section 1 (very 

 rare). 



LuNXLirAunirM cukttm. Hall. (Fig. 185.) (Pal. N. Y., 

 Vol. Y.. Pt. L, p. 437, PI. LXXL) 



Distinguisliing Cliaracters. — Sub-trigonal outline; long 

 truncated end. with a thickening 

 along the margin ; twenty-five to 

 thirty narrow rounded, or sub-angu- 

 lar plications, with wider interspaces, 

 crossed by fine lamellose concentric 

 striae. 



Found "in the Marcellus shale, at 

 Alden, Erie County, N. Y., and in the 

 Hamilton shales ^* * * at * * * 

 (Hall.) 



Fig. 184. Lunulicardium ornu- 

 tum. A right valve, from the 

 Chemung group (from Hall). 



Fig. 185. Lunulicardium 

 curium. Right valve, from 

 the Marcellus shale of Alden, 

 Erie Co., N. Y. (from Hall). 



Hamburg, N. Y." 



