68 A MANUAL OF ATiIEEICA?-; LAND SHELLS. 



Slave Lake to Texas and Florida. lu tbe Pacific Province it Las been 

 found in Sitka, and at Lake Tahoe and San Gorgonio Pas8 in Cali- 

 fornia. In the Central Province in Colorado and Nevada. It may 

 eventually be found to inhabit the whole North American continent. 



Animal bluish black upon the head, neck, and eye-peduncles, lighter 

 on the sides and base ; foot very narrow, thread-like, with a caudal 

 mucus pore. 



The American form here under consideration was described by Mr. 

 Say under the name Helix chersina. Judging from its shell alone, it 

 seems identical with the European Z.fulvus. It has thus been consid- 

 ered one of the circumpolar species common to the three continents, 

 and is so treated above. My confidence of this identity, however, is 

 shaken by a study of the description and figure by Lehniann (Leben- 

 den Schnecken, &c., p. 79, Plate X, Fig. 24), of the dentition of the 

 European Z. fulvus. He gives 86-100 rows of 25-1-25 teeth ; the 

 first two laterals he makes tricuspid, while they are only bicuspid in 

 our form. The marginals appear to be bifid. The question of identity 

 must therefore, I fear, be considered as still open. 



It is found under, and in the interstices of, wet, decaying wood, un- 

 der layers of damp leaves in forests, and under fragments of wood on 

 the borders of ponds. 



The above-named localities prove this to be a widely spread species. 

 Its diminutive size has probably prevented its being observed in other 

 places. It offers but few varieties, and is easily distinguished by its 

 conical form and thin, amber-colored, transjiarent shell. It is a very 

 beautiful and delicate little species. The spire is elevated, turretcd, 

 attaining even seven full volutions, with an obtuse apex; at other 

 times it is much lower, with a somewhat pointed apex, and not exceed- 

 ing five volutions. In the latter case, the base is of course much 

 broader in jiroportion to the height, and the outer whorl is obtusely 

 carinated. This carinated form is H. egena of Say, of which Dr. Binney 

 writes — 



" I have recently examined the original specimen of the shell de- 

 scribed by Mr. Say as HcUx egcna, and by him deposited in the collec- 

 tion of the Academy of Natural Sciences, in Philadelphia. I could not, 

 on careful comparison, detect any difference between it and the de- 

 pressed variety of H. chersina. Mr. J. S. Phillips, the obliging curator 

 of the department of Conchology in that institution, joinjed me in the 

 opinion that the two are clearly identical." 



