260 PALAEONTOLOGY OF CALIFORNIA. 



lip broadly inerusted above, thickened in front of, and below the 

 umbilicus. Umbilicus subperforate, a thin striate incrustation 

 running up into it, and extending below, parallel with the anterior 

 portion of the labium. Surface marked by faint lines of growth. 



This is by far the largest Naticoid in the American Cretaceous, and, apart from 

 its size, can be distinguished from all the other species by its elongate form and the 

 striate umbilicus. 



EUSPIRA, Agas. 



E. TABULATA, n. S. 

 PL 35, Fig. 4. 



Shell thick, robust, pyriform; spire elevated turrited; whorls 

 five; upper surface directly or obliquely truncated ; suture faint. 

 Body whorl flat above, concave immediately below the angle, and 

 broadly expanded towards the base. Surface plain. Aperture 

 biangular behind, rapidly widening, and round in front; outer 

 lip simple, but rather thick; inner lip inerusted narrowly above, 

 thickened over, and in front of the umbilicus. Umbilicus imper- 

 forate, a small angular ridge revolving from the umbilicus, nearly 

 parallel with the margin of the inner lip. 



Figure, natural size. 



A rare shell, and entirely unlike any other in the formation. It seems to be 

 most closely allied to the Oolitic genus Euspira, and altogether looks much more 

 like a Jurassic than like a Cretaceous species. 



CHEMNITZIA, d'Orb. 



C. ZEBRA, 11. S. 

 PI. 35, Fig. 5. 



Shell elongate, slender-conical ; spire high, whorls numerous, 

 flattened, or very slightly convex on the sides ; suture linear, im- 

 pressed; body whorl flattened above, rounded below. Surface 



