269 



y^^ 



Fig. 191. Cypricardinia indenta. Left and right valves, enlarged to three diameters. 



distinct on left valve; rounded umbonal slope of right valve, 

 and sub-angular umbonal slope of left valve; strong, une- 

 qually distant concentric undulations and liner stride; 

 radiating striiP, and a second set of stri<p vertical to the 

 concentric lamelhp. 



Found in the lower two feet of the Moscow shale, at Sec- 

 tions 4 and 5 (one speciiuen) ; in the Deniissa bed, at Section 

 5 (abundant) ; also in the shale and limestone beds between 

 the Trilobite and Strophalosia beds (fairly common). 



Genus ELYMELLA. Hall. 



[Ety. : Ely 11108, a case.] 

 (1885 : Pal. N. Y., Vol. V., Pt. I., p. 1.) 



Shells with equal inequilateral valves, ovate-elliptical in 

 outline. The anterior end is short and rounded, the poste- 

 rior end narrower and rounded at the extremity. Closely 

 incurved beaks; prominent umbones; a short cardinal line ; 

 and concentric lines of growth, which are sometimes lamel- 

 lose, — mark this genus. 



Elymella nuculoides. Hall. 

 (Fig. 192.) (Pal. N. Y., Vol. Y., 

 Pt. I., p. 503, PL XL.) 



Distinguishing Character s . — 

 Small size; obliquely ovate outline; 

 regularly curving margins; hinge 

 line straight, a little less than half 



, , , !• j_i 1 11 /-• ^'**- ^^~- Eli/niella nuculoides. 



the length OI the shell ; hue COnCen- specimen, retaining both valves in 



. . conjunction, from Hamilton group 



trie strite, fasciculate on the surface (from Haii). 

 of the shell, giving rise to strong undulations. 



