EUROPEAN SPECIES OF VERTIGO. 171 



within, lamelliform ; 2 columellar, or often 3, the upper one 

 stronger; 2 lamelliform palatals, forming external furrows; 

 finally, in adult shells, very often a dentiform fold at the 

 insertion of the outer lip. Peristome a little expanded, acute, 

 with a whitish thickening deep within, and encircled ex- 

 ternally at the periphery with a thick and strong whitish lip 

 [crest] . Outer margin sinuous above, arcuate anteriorly, the 

 margins joined by a rather strong callus. Length 2y 2 , diam. 

 li/ 4 mm. (Bgt.). 



Algeria: debris of the Harrach at Algiers, of the Oued 

 Tademit near Oran, and the Safsaf near Philippeville ; type 

 loc., fossil in Pleistocene deposits of the Oued Tademit, 15 

 leagues S.-W. of Djelfa. Tunis: debris of the Oued Sidi- 

 Aich (Bgt.). 



Vertigo discheiHa- BOURGUIGNAT, Paleont. Algerie, 1862, p. 

 78, pi. 4, f. 3, 4; Malac. Alger. ii, 1864, p. 105, 313, pi. 6, 

 f. 45-47. LETOURNEUX et BOURGUIGNAT, Prodr. Malac. 

 Tunisie, 1887, p. 109. 



Var. unilabiata Bourguignat. Like the type but without 

 external peristomial callus. Drift of the Harrach. 



50. VERTIGO MARESI Bourguignat. PI. 16, figs. 10, 11. 



Shell pygmy, rimate, globuloid, glossy, pellucid, fulvous, 

 smooth. Spire very obtuse, the apex very obtuse, paler. 

 Whorls 5, convex, rapidly increasing, separated by a deep 

 suture, the penult largest, inflated-globuloid ; the last small, 

 contracted, tapering, a little compressed basally, straightened 

 in front, often in some specimens a little swollen and angu- 

 late-flattened at the suture. Aperture lunate, somewhat half- 

 rotund, ringent, many-folded: 2 lamelliform parietal folds, 

 the inferior deeper and stronger ; 2 or often 3 columellars, the 

 upper one stronger and the lower remote and very minute; 

 2 palatals, lamelliform, forming furrows externally. Peris- 

 tome simple, acute, slightly expanded, slightly thickened 

 within, and externally encircled by a more or less strong, 

 vinaceous-fulvous, very rarely paler lip [crest] ; outer margin 

 sinuous above, slightly arching forward, the margins joined 

 by a thin callus. Length 2, diam. 114 mm. (Bgt.). 



