VITRINA. 139 



Section AFRICARION, Godwin- A listen, 1884. Shell like Heli- 

 carion. Animal with truncate tail and pore. The right shell- 

 lobe is broad, extending towards the shell ; it narrows posteriorly, 

 and is continuous round to the left shell-lobe. The right dorsal 

 lobe is small, but the left- very ample and continuous. The 

 ridge of the foot behind, just beneath the posterior margin of 

 the shell, forks into two ridges, and this portion of the shell rests 

 in the long triangular depression between them. Jaw with cen- 

 tral inferior projection. East Africa.. 



Genus VITRINA, Drap., 1801. 



I. Typical Species; mostly of northern regions. 



These are all small, fragile, inhabiting northern and temperate 

 regions, where Helicarion does not occur. The larger frequently 

 more solid species, which are inhabitants of warm countries and 

 of the eastern hemisphere only, are in many cases riot distin- 

 guishable by the shell alone from Helicarion, and as the animals 

 of but few of the species have been examined, very little can be 

 done towards a natural arrangement of the species. Doubtless 

 species are admitted into either group which really belong to 

 the other ; and in order not to run the risk of making still more 

 confusion, I am compelled to retain in Yitrina nearly all the 

 species described under that name, unless removed to Helicarion 

 by subsequent investigators. 



Section SEMILIMAX, Stabile, 1859. 



Y. DIAPHANA, Drap. PL 30, figs. 77-86. 



Shell thin, smooth, shining, diaphanous; greenish hyaline; 

 whorls 2J, rapidly increasing, the last dilated ; aperture almost 

 horizontal, very large, the outer margin submembranaceous, the 

 colurnellar margin somewhat curved. Diam. G'5, alt. 3 mill. 



Germany, Switzerland, France, Sweden, England. 



The synonyms are numerous : V. pellucida, Yoith ; Hyalina 

 vitrea, Studer ; Helix limacina, Alten ; H. virescens, Studer ; H. 

 palliata, Hartm. ; V. albina, Ziegler. To these I add V. Pego- 



