108 PALAEONTOLOGY OF CALIFORNIA. 



I have hesitated about placing this shell positively in either of the above genera; 

 since, except for the patulous umbilicus, it would be undoubtedly a Lunatia; while 

 this character is hardly conclusive, without the confirmatory one of the flattened 

 or canaliculate upper portion of the whorl. 



Named in honor of my friend, Mr. T. A. Conrad, one of the pioneers of Ame- 

 rican Cretaceous Palaeontology. 



GYRODES, Con. 



G. expansa, n. s. 



PI. 19, Fig. 62, a, b, c. 



Shell flattened; spire low; whorls four; apical channel slightly 

 concave, or, more usually, flat, angulated, or rounded on the 

 margin, but never carinate; whorls marked by a faint depression 

 below the angle, most marked in old specimens. Mouth oblique, 

 expanded laterally ; lips simple. Umbilicus patulous, margin 

 rounded, both on the shell and cast. 



Figures, natural size. Figures a and b illustrate the adult form, showing the 

 remarkable expansion of the body whorl. Fig. e is from a younger specimen. 



This species is probably most nearly allied to G. alveata, Con. ; but the whorls 

 are less numerous, and the shell is more expanded. This character will also dis- 

 tinguish it from G. abyssinis, Naticaid., Morton. 



Localities: Hills southwest of Martinez; Pence's Eanch, above Oroville, Butte 

 County ; north fork of Cottonwood Creek ; Tuscan Springs ; and Texas Flat, Placer 

 County (Division A.). Also in the Siskiyou Mountains, Siskiyou County ; and 

 at Jacksonville, Oregon, where I found a few distorted casts only. 



NEVERITA, Risso. 



N". secta, n. s. 



PI. 29, Fig. 220, and 220 a. 



Shell obliquely subglobose ; spire moderately elevated; whorls 

 five, almost entirely enveloped; apex acute; suture linear. Mouth 

 acute behind, broadly rounded in advance ; outer lip broadly 

 rounded, acute; inner lip nearly straight, with a moderately 



