170 EUROPEAN SPECIES OP VERTIGO. 



48. VERTIGO LATASTEANA Let. et Bgt. 



Shell very minute, slightly rimate, swollen ventricose, sub- 

 ovate-spherical, fragile, diaphanous, corneous, smooth; spire 

 short, very obtuse; whorls 5, convex (the embryonic small, 

 median relatively ample and turgid, the last smallest, dimin- 

 ishing and tapering) , rapidly increasing, separated by a rather 

 deep suture; last whorl small, less wide than the penult, ex- 

 ternally compressed, scrobiculate, elegantly marked with a 

 lip [crest] behind the peristome, compressed at base and angu- 

 lar around the umbilical crevice; above ascending to the in- 

 sertion of the lip. Aperture suboblique, very small, con- 

 tracted, subtriangular and 5-toothed as follows: 2 long and 

 rather strong parietal teeth; 1 robust columellar; 2 lamelli- 

 form palatals, reaching the outer margin, the upper one 

 stronger and forming a deep external pit. Peristome paler, 

 rather thick, spreading throughout; columella very short; 

 outer margin sinuated in the position of the external pit, 

 and produced forward in a sort of little beak; columellar 

 margin dilated; the margins remote. Length 2, diam. 1 mm. 

 (L.&B.}. 



Tunis : debris of the Oued Sidi-Aich. 



V. [ertigo] latasteana LETOURNEUX et BOURGUIGNAT, Prodr. 

 Malac. Tunisie, 1887, pp. 109, 166. 



This very small species, remarkable for the contraction of 

 its aperture and the spherical shape, cannot be assimilated 

 with any of the living Vertigos. We see only V. milne- 

 edwardsi of the hill of Sansan which resembles it not only 

 in respect to the denticulation but in shape and contours 

 (L.&B.). 



49. VERTIGO DISCHEILIA Bourguignat. PL 16, figs. 8, 9. 

 Shell very minute, rimate, globose-oblong, glossy, subpel- 



lucid, corneous, obliquely substriatulate under the lens. Spire 

 tapering, obtuse, the apex smooth, paler, obtuse. Whorls 5, 

 convex, rather rapidly increasing, separated by an impressed 

 suture; the last small, tapering, a little compressed basally, 

 straightened in front. Aperture a little oblique, lunate, half- 

 round, ringent, with many folds : 2 parietals, the lower deeper 



