754 



NORTH AMERICAN INDEX FOSSILS. 



500. A. (Lispodesthes) nuptialis White. (Fig. 1096, b, c.) Cretacic. 

 Body whorl with angulation that extends into the spinose pos- 

 terior prolongation of the lip; anterior canal straight and rapidly 



Fig. 1096. a, Aporrhais (Perissoplera) prolabiata ; b, c, A. [Lispodesthes) nupti- 

 alis. (After Stanton.) 



tapering; surface of whorls generally completely enveloped in 

 callous deposits. 



Colorado formation of New Mexico, Arizona, etc. 

 501. A. (Tessarolax) distorta Gabb. (Fig. 1097.) Cretacic. 



Spire concealed by smooth surface deposits; body whorl with 

 two carinations, each of which bears an irregular blunt node, the 

 lower one formed after the upper one, and each extending into 



Fig. 1097. Aporrhais [Tessarolax) distorta, slightly reduced. (After Gabb.) 



a canaliculate spine; anterior and posterior ends of aperture 

 drawn out into similar curved canaliculate spines. 



Nanaimo of Vancouver, B. C, and Chico of California. 



