128 PALEONTOLOGY OF CALIFORNIA. 



Ranch, Butte County; and Texas Flat, Placer County. One of the most abun- 

 dant fossils in the State, and very characteristic of the lower group of Cretaceous 

 strata. 



A. ANGULATA, 11. 8. 

 PI. 20, Fig. 84. 



Shell elongated; spire high; whorls numerous, number un- 

 known; upper whorls convex, widest a little below the middle; 

 last whorl sharply and acutely angulated, sloping and gently 

 concave above and below the angle ; suture impressed. Surface 

 ornamented by fine, thread-like, revolving lines, and by sinuous 

 lines of growth. Canal long, narrow, straight. Outer lip curved, 

 unicarinate, exact form unknown. 



Figure, natural size. 



Locality: In a single stratum of greenish-gray limestone, at Bull's Head Point, 

 near Martinez. Very rare. (Div. B.) 



I am indebted to Mr. Mathewson for the chance of describing this species. The 

 specimen figured is the only one I have seen showing the body whorl, and in this 

 case entirely denuded of its shell. Another specimen, consisting of three whorls 

 of the spire, is in the collection of the Survey. Mr. Brewer collected three spe- 

 cimens at Huling Creek, near the Cottonwood Creek locality, resembling this 

 species in surface ornamentation and in the shape of the upper whorls, but in 

 which the last whorl was distinctly bicarinate. None of the specimens show 

 either lip or canal, and the lower carina is less prominent and less acute than the 

 upper. They are probably a variety of the present species. 



A. Californica, n. s. 



PL 29, Fig. 230 a, b. 



Shell small; spire high; whorls eight, convex ; suture deep. 

 Mouth long, prolonged below into a moderate, straight canal; 

 outer lip prominent, somewhat variable in shape, usually regu- 

 larly concave above, rounded on the external margin and angular 

 below, prolonged above, on its outer edge, into a long falciform 

 process, which extends almost as high as the spire; inner lip but 

 slightly incrusted. Body whorl nearly plain, with an angle 

 above bearing a few tubercles; this angle is prolonged on the 



