TERTIARY FOSSILS. 27 



CARDIUM, L. 



C. Meekianum, n. s. 



PI. 7, Fig. 46. 



Shell resembling C. corbis ( Calif 'ornianum and Nuttallii), but 

 oblique; beaks large, strongly incurved and pointed forwards; 

 anterior end prominent and broadly rounded; posterior end 

 abruptly truncated and very oblique. Surface marked by 

 twenty-two large radiating ribs; tbese ribs, in the young shell, 

 are acute, becoming rounded as it increases in size, and ulti- 

 mately becoming distinctly flattened on top; they are crossed by 

 irregular, curved, subsquamose plates, which towards the beaks 

 lose their lamellar character, and are represented by little tuber- 

 cles; the posterior face of the shell is not costate, or the ribs are 

 represented by only a few indistinct radiating lines; the inter- 

 spaces between the ribs are narrow and flat, or concave. 



Figure, natural size. 



Locality: Humboldt County, associated with Callista Voyi, &c. ; collected by 

 Mr. Voy. 



From C. corbis, Mart, (which, according to Carpenter, is the same as Californi- 

 anum and Nuttallii of Conrad), this shell can be distinguished by its form, which 

 is more oblique than the most inequilateral varieties of that species. The ribs are 

 proportionately larger and less numerous, being only about two-thirds as many. 

 The abrupt posterior truncation, and the absence of ribs on that part, are also 

 well-marked characters. 



I take pleasure in dedicating this fine species to my friend, Mr. F. B. Meek, 

 of Washington, D. C. 



CONCHOCELE. K Gen. 



Shell irregularly quadrate, very inequilateral; a sharp angular 

 ridge passes from the beaks to the posterior end, between which 

 ridge and the cardinal margin the surface is suddenly sunken, 

 presenting the appearance of an offset, the truncation being at 

 nearly a right angle, beyond which the surface retains the same 



