16 THE SPECIES OF 



crescentes, ultlmus utrinque convexior, antice turgidulus, vix descendens, 

 supra medium fascia castanea, utrinque albido-marginata cinctus, basi 

 convexus ; umbilicus mediocris, conicus ; apertura perobliqua, auriformi, 

 lunaris; perist. albo-labiatum, marginibus convergentibus, dextro perar- 

 cuato, expanse, columellari arcuato-declivi, reflexo, superne dilatato. 

 [Pf.j 



SYNONYMS AND REFERENCES. 



Helix Mormonum PFEIFFER, Proc. Zool. Soc. London, May, 1857, p. 109. 



Diam. maj. 29, min. 24, alt. 12 mill. Hob. Mormon Island, Cali- 

 fornia. 



The above is Pfeiffer's description. I have not seen 

 the shell, but through the kindness of Mr. Cuming I have 

 been able to give a figure of it. 



HELIX COLUMBIAN A LEA ......... vol. ii. p. 169, pi. v. pi. xiii. a. fig. 1. 



Helix Columbiana TROSCHEL, Arch, flir Nat. 1839, ii. 221. 



CHEMNITZ, ed. 2, i. 332, pi. Iviii. fig. 10-12 (1846). 



KEEVE, Con. Icon. No. 692 (1852). 



PFEIFFER, 1. c. iii. 262. 



Helix labiosa GOULD, vol. ii. p. 170; U. S. Ex. Ex. Moll. p. 67, fig. 35. 

 PFEIFFER, 1. c. p. 262. 



I think there can be no doubt of the identity of these 

 two species. Lea's description was drawn from a worn 

 specimen, denuded of its hairs. It will be remarked that 

 Reeve and Pfeiffer describe it as being covered " pilis 

 brevibus." The latter author gives Gould's description of 

 labiosci) not having seen the shell, but records his belief 

 in the indentity of the two. 



Mr. Thomson gives me the following note on the ani- 

 mal of this species. It seems more than probable that he 

 has confounded it with some other shell, as his observa- 

 tions do not agree with those given on p. 171 (vid. Notes, 

 p. 8). 



" Animal twice as long as the breadth of the shell, dark 

 slate color, almost black on the head and tentacles ; a 

 black line running along each side of the back from the 

 base of the longer tentacles ; body covered with com- 



