128 TERRESTRIAL AIR-BREATHING MOLLUSKS. 



marginals from 2 adjoining transverse rows), 23 — 1 — 23 teeth, with 4 per- 

 fect laterals. This lingual is peculiar in having its marginals bluntly bifid, as 

 in Nanina and Vitnna. Some of the marginals are even trifid. In this re- 

 spect it agrees with the dentition of VUrinoconus, as does also Z. fulvus, but 

 from that genus it differs in having its lateral teeth tricuspid like the centrals. 

 Its dentition is altogether peculiar. 

 Genitalia not observed. 



Zonites Stearnsi, Bland. 



With land shells from the west coast, kindly sent to me for examination by 

 my friend Mr. Stearns, I lately noticed a single specimen of a form from 

 Astoria, Oregon, allied to Microphysa Lansingi. It is larger, more elevated, 

 and more distinctly striated than that species, has 7 whorls, with rather wider 

 and more rounded aperture, but without the lamella within the outer margin 

 of the peristome. The measurements are, greater diameter 4, lesser 3h mill. ; 

 height 2^ mill. 



Having before me a single specimen, I am unwilling formally to describe the 

 species, which for the present I designate as Zonites Stearnsi (Bland). 



Fig. 46. 



Zonites Stearnsi. 



This is all the information I can give on this species. It is copied from Bland, 

 Ann. of Lye. of Nat. Hist, of N. Y., XL 76, Fig. 3 (1875). 



Subgenus GASTRODONTA, Albers. 

 Animal (of Z. suppressus) bluish-black, darker on the head, eye-peduncles, 

 and neck ; eye-peduncles long and filiform, tentacles short. Length twice the 

 Fig. 47. diameter of the shell. On the upper surface of the extremity of 

 the foot is the mucus pore, a longitudinal fissure or furrow from 

 which mucus exudes in great quantities, and which the animal 

 shuts and closes at will. A distinct locomotive disk and longi- 

 suppressus, tudiual furroAvs above the margin of the foot, 

 enlarged.' gj^^^ subperforate or umbilicated, orbicularly depressed, light 



horn-color, sometimes glassy, with more or less numerous wrinkle-like striae ; 

 whorls 5 - 7 ; aperture lunate, its base generally furnished with fold-like den- 

 ticles not reaching its margin ; peristome simple, acute. 



