VITRINA. 155 



margined ; whorls 3^, rapidly enlarging, the last more convex 

 below ; aperture with subparallel margins, the columellar margin 



membraneous. Diam. 17, alt. 8 mill. 



Abyssinia. 



This is V. Martensi, Jickeli, and F. Isseli, var., of the same 

 author, not Morelet. Jickeli also considers his F. planulata a 

 synonym (figs. 62-64) and his F. devexa (figs. 65-67) a variety. 



Y. MAMILLATA, Martens. PI. 34, figs. 68-70. 



Depressed, thin, unequally arcuately striate, shining, yellowish 

 green, suture brown-margined; whorls 3^, rapidly increasing; 

 aperture lunatel}' ovate, the outer margin slightly sinuous above, 

 the columellar margin membraneous. Diam. 16, alt. 8 mill. 



Abyssinia. 



Yery close to F. Isseli, Morelet. 



Y. HELICOIDEA, Jickeli. PI. 34, figs. 71-73. 



Subglobose, thin, slightly striate, pellucid, yellowish, a little 

 shining; suture impressed, thread-margined ; whorls 3-J, convex, 

 rapidly increasing, the last descending, subplanulate above, more 

 convex below ; lip thin, margined within, slightl}' membraneous. 



Diam. 9*75, alt. 6*75 mill. Abyssinia. 



Y. MILNE-EDWARDSIANA, Bourg. PL 34, figs. 74-76. 



Oblong semiglobose, thin, shining, diaphanous, imperforate, 

 striated, striae subpliciform on the last whorl, with slightly per- 

 ceptible dents in spiral series ; yellowish ; whorls 3, with submar- 

 gined suture, the last large, obliquely flattened, more convex 

 below ; lip very fragile, reflected at the columellar insertion. 



Diam. 15, alt. 12 mill. 



Mts. of Abyssinia. 

 Y. RAFFRAYI, Bourg. PI. 34, figs. 77-79. 



Depressed globose, imperforate, very thin, diaphanous, very 

 shining, smoky fawn-color, smooth, subplicate at the suture of 

 the last whorl ; whorls 3^, the suture becoming submargined in 

 the last, which is a little obliquely flattened above and more 

 convex below; lip thin, slightly reflected at the columellar 

 insertion. Diam. 9, alt. 6 mill. 



Mts. of Abyssinia. 



The shell is entirely membraneous, and so elastic that it may 

 be pressed together by the fingers and flattened, resuming the 

 normal form when the pressure is removed. 



