242 



Found ill the Stictopora and Demissa bed.s. at Section ."> 

 (rare) ; in the shale nine to seventeen feet below the Encrinal 

 limestone, at Section 7 (rare): and at "Hamburg. Erie 

 County, N.Y." (Hall.) 



AvicuLOPECTEN iNsiGNis. Hall. ( Fig. 1.54. ) (Pal. X. Y., 

 Vol. v., Pt. I., p. 34, Pis. I.. HI.. LXXXI. ) 



Distinguishing Clmracters. — Smnll size: moderate ol)- 



V 





Fig. 154. Avicuhjiirrtrn ntsigiiis. A left valve: iuterinr : a ;.„:jt valve, from Ham- 

 burg-, Erie Co., X. Y., the specimen being embedded in shale shuws the ornamentation 

 on the interior (from Hall). 



liquitv; hinge nearly efpial to the length of the shell: nearly 

 central beak ; strong radiating costa?. 



Found at '' Hamburo-. Erie Countv. X. Y." ( Hall. ) 



Genus LYRIOPECTEX. H.vll. 



[Ety. : Lyrion. Ijre — Pecteu.] 

 (1884: Pal. N. Y., Vol. V., Pt. I., p. xii.) 



Shell like Aviculoi)ecten, but differing from that genus in 

 its short hinge line and very small anterior ear. 



Lyriopecten o r b I c r i. a t u s. 

 ---^^1|^~ '•"' Hall. (Fig. 155.) (Pal. X.Y., 



'\\ Vol. v.. Pt. I., p. 42. Pis. IV., 



'^^ LXXXH.) 



Distinguishing Characters. — 

 Large size: orbicular outline; 

 convex left valve: concave, flat, 

 or slightly convex right valve: 

 numerous strong, rounded radii 

 crossed by concentric sharp lines, 



Fig. 155. Lyriopecten orbicidatus. -, j_ i i i t 



The tjTJe specimen from the Encrinal aUU Separated DV Oroadcr COll- 

 limestone. on the shore of Lake Erie, 



N. Y. (from Hall). CaVC SpaCeS. 



