CRETACEOUS FOSSILS. 159 



F. Cooperii, Gabb. 



(F. (H.) Cooperii, Gabb; Pal. Cal., Vol. 1, p. 86, pi. 28, fig. 207.) 



UROSYCA, N. Gen. 



Shell thin, pyriform, spire very slightly elevated, body whorl 

 long. Surface transversely striate or cancellate. Aperture broad 

 above, narrow and produced below; outer lip simple, inner lip 

 very slightly incrusted; canal long, slender, and slightly twisted. 



This genus seems to be closely allied to Ficopsis, but differs from it in its more 

 pyriform shape, and in the canal being more slender, proportionally longer, and 

 contorted instead of being perfectly straight. Mr. Conrad has placed Ficopsis as 

 the next genus to Ficus, and I think correctly. We have thus, at least three 

 genera of this group, characterized by their general ficoid shape, thin shells, low 

 spires, and more or less delicate sculpture. In the absence of the animals, it is 

 difficult to ascertain the family relations of shells so closely allied in form as these 

 are to some of the Fusince, and it is not improbable that there are many fossil 

 shells called by the promiscuous appellations of Fusus and Pyrula, which really 

 belong to this family. 



U. CAUDATA, U. 8. 

 PI. 27, Fig. 38. 



Shell moderately large, pyriform, spire low, whorls five, the 

 upper rounded, the body whorl subangulated by three nearly 

 equidistant, nodose, revolving carina?; top of whorl slightly 

 sloping, interspaces between the ribs slightly concave, anterior 

 portion deeply excayated. Surface crossed by numerous small 

 revolving striae. Aperture broad, outer lip simple, inner lip 

 slightly incrusted, canal long, slender, slightly twisted. 



Length, 2.35 inch; length of aperture, 2.15 inch; width of body whorl, 1.3 

 inch. 



Rare in the Martinez Group, Martinez. Mr. Mathewson. 



Resembles somewhat Ficopsis Cooperii in style of ornament, but can be dis- 

 tinguished by its greater size, lower spire, broader body whorl, the presence of 

 three instead of two carinas, and by the curved canal. 



