204 



of the shell, visible only in the most perfectly preserved 

 specimens. 



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

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

 in the Genesee shales (especially abundant in the lower black 

 bands of Section 1, etc.); and on the Lake Shore; in the 

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

 tween nine and twelve feet below the Encrinal 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). 



LUNULICAEDIUM ORXATUM. Hall. 



(Fig. 184.) (Pal. N. Y., Vol. Y., Ft, 

 I., p. 437, PI. LXXI.) 



Bis t in g u is h in g Characters. — 

 Large size; broadly obovate out- 

 line: forty-five to sixty regular 

 flattened radiating plications, with 



Fio. 184. Lunulicardium orna- . -, _ n 



turn, a right vahe, from the narrow interspaces, and crossed 



Chemung group (from Hall). . -. ■, . 



by closely-arranged, undulating, 

 lamellose, concentric striae. 



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

 rare). 



Lunulicardium curtum. Hall. (Fig. 185.) (Pal. N. Y., 

 Vol. V.. Pt. 1., p. 437, PI. LXXI.) 



Distinguishing Characters.— 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 bv fine lamellose concentric 



v 



striae. 



Found "in the Marcellus shale, at 

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

 Hamilton shales * * * at * * * 

 Hamburg, N. Y." (Hall.) 



Fio. 185. I/unulicardium 



curt inn. Right valve, from 

 tin- Marcellus shale of Alden, 

 Erie Co., N. V. I from Hall). 



