TERTIARY FOSSILS. 17 



Figure, slightly magnified. 



Locality: From the Post- Pliocene of San Pedro and Santa Barbara. Also found 

 living at Monterey. The epidermis in the living specimen is of a rich eoffec- 

 brown. The living specimen, from which the original description was written, 

 was immature, having a full whorl less than the mature fossils now under con- 

 sideration ; the shell was also much thinner. 



CALLIOSTOMA, Swains. 

 Zizyphinus, Gray. 



C. TRICOLOR. 



PI. 3, Fig. 28. 

 (C. tricolor, Gabb ; Proc. Cal. Acad. Nat. Sci., Jan. 1865, p. 186.) 



Shell small, conical; spire elevated, whorls seven; first whorl 

 smooth, others concavely to convexly sloping above, more or less 

 distinctly biangular on the margin; suture small, impressed. 

 Surface closely and minutely marked with fine revolving granu- 

 lar ribs. Aperture subquadrate, internally nacreous; inner lip 

 thick; outer lip and base acute. 



Figure, a magnified view of a fresh specimen. Length about .5 inch. 



Locality: Post-Pliocene, San Pedro. 



Dr. Cooper has collected this shell, living, along the coast from San Diego to 

 Half Moon Bay. Its peculiar colors suggested the specific name. It is a light- 

 brown, banded by spiral lines of purple interrupted by white spots. 



Figures 29 and 30 represent two of the many forms which have been discovered 

 in the California Miocene, of which sufficient material has not yet been accumu- 

 lated for satisfactory determination. Both of these specimens were found in the 

 San Emidio Canon, twenty miles west of Fort T6jon, Los Angelos County, in a 

 hard Miocene sandstone. 



PAL. VOL. II. 



