CRETACEOUS FOSSILS. 175 



suture linear, impressed. Surface marked by a few, distant, im 

 pressed, revolving lines, variable in number. Aperture long, 

 rounded in advance, inner lip bearing one large and one smaller 

 and less prominent fold in advance. 



Length, .4 inch ; width of body whorl, .24 inch ; length of aperture, .27 inch. 



Not rare, with the preceding species. 



This shell can be distinguished from all previously described members of the 

 family in California, by the simple style of its sculpture, consisting of simple im 

 pressed lines; R. (Cinulia) pinguis having elevated ribs, Ringicula varia having 

 grooves crossed by minute elevated lines, and the others being too different in 

 shape to permit of a confusion. 



R. PINGUIS, Gabb. 



(Cinulia pinguis, Gabb ; Pal. Cal., Vol. 1, p. 112, pi. 29, fig. 221.) 



ACEPHALA. 



MARTESIA, Leach. 



M. CLAUSA, Gabb. 



(M. clausa, Gabb; Pal. Cal., Vol. 1, p. 145, pi. 22, fig. 115.) 



This species was described from the Chico Group. During the last two or three 

 years several specimens have been obtained from the Martinez Group, at Martinez, 

 and from the Tejon Group at Martinez, ten miles west of Griswold's and Tejon. 

 In these more recent forms I can find no characters different from the original 

 type ; and Mr. Tryon, whose great experience in this family renders his opinion 

 of especial weight, agrees with me in believing them all to belong to the same 

 species. 



SOLEN, Linn. 



S. Gen. Hypogella, Gray. 



S. (H.) CUNEATUS, n. s. 



PI. 29, Pig. 61. 



SHELL small, narrowed anteriorly, wider behind ; hinge margin 

 straight; beaks anterior, subterminal; margin slightly excavated 



