TERTIARY FOSSILS. 11 



giuate above the umbilical region, and nea: the lower edge is 

 marked by an oblique groove. 



Figures, 17 and 17 a, natural size ; 17 b, magnified view from above. 



Locality: Walnut Creek, from the Miocene. A form somewhat resembling this 

 has been found by Dr. Cooper at San Pedro ; but it differs in the spire being more- 

 developed, and in the body whorl being less oblique and more expanded laterally. 



CANCELLAKIA, Lam. 

 S. Gen. Euclia, H. and A. Ad. 



C. (E.) TRITONIDEA, U. S. 

 PI. 2, Fig. 18. 



Shell large, robust; spire elevated, nearly as long as the 

 mouth; whorls five, the first two and a half round and smooth, 

 others bluntly angulated and descending straight, or with a 

 slightly convex slope above ; suture irregular, nearly obliterated 

 by small lamellae passing up from the succeeding whorls, in 

 continuation of the lines of growth. Surface marked by a series 

 of blunt nodes on the angles of the whorls, from which ribs or 

 ridges, very irregularly dispersed, run to the suture above and 

 downwards almost to the base of the shell; these are crossed by 

 a large number of irregular revolving ribs of small size. Aper- 

 ture suboval, broadest towards the base; inner lip heavily 

 incrusted, bearing two large and one or two smaller folds. 

 Umbilicus covered. Canal almost obsolete, slightly bent back- 

 wards. 



Figure, natural size. 



Locality : Picked up on the beach near San Pedro, by Dr. Cooper, and supposed 

 to have washed out of the Post-Pliocene beds of that locality. This opinion is 

 strengthened by the appearance of the specimen, it resembling in every respect a 

 fossil, rather than a mere beach specimen of a living shell ; and, in addition to 

 that, no such shell, or even a fragment, has ever been found to indicate that the 

 species may still be living. 



