GRANOPUPA. 333 



the more advanced forms of the two areas, though the homol- 

 ogy of the principal teeth is obvious. 



Distribution of Granopupa. 



In its mode of life, which is essentially that of Pupilla and 

 many Vertigos, Granopupa granum has invaded a new station 

 (or perhaps more properly, it has remained in the primitive 

 station of its ancestors) ; this allowed it to spread more widely 

 than the allied genus Abida, which is confined for the most part 

 to rocky or mountainous and usually limestone districts, where 

 they live on cliffs and rocks, like Clausilia. No fossil forms 

 of Granopupa are known, but its presence from the Canaries 

 to Persia indicates considerable antiquity. 



The subgeims Rupestrella is less widely spread, though 

 some species such as rhodia and especially phiUppii have wide 

 ranges. The species inhabit the borders of the Mediterranean, 

 Adriatic, Aegean and Black seas from. Bougie in Algeria to 

 Armenia. The Algerian group was evidently derived from 

 that of Italy and Sicily by way of a former land bridge sep- 

 arating the eastern and western basins of the Mediterranean. 

 In Europe, none are found west of Italy; France and Spain 

 being without species of Rupestrella. Ct. Caziot considers it 

 a group of the southern Alpic center, but beyond limiting its 

 northward spread locally, it may be doubted whether the Alps 

 had anything to do with the evolution of the group. They are 

 not mountain snails. 



Key to Species of Granopupa. 



a 1 . Four palatal folds, in all 7 or 8 teeth. granum, no. 1. 



a 2 . Two palatal folds. 



b 1 . Distinctly conic, diarn. fully half the alt,; 6-8 teeth, 

 61/2-7 whorls. Dalrnatia. 



Chondrina spclta, Vol. XXV. 



&-. Oblong-conic or fusiform, more slender; 46 teeth. 

 c 1 . European species, Italy to Greece, Crimea, 

 and Asia Minor. 



d 1 . A parietal and usually an angular lam., 

 1 or 2 columellars, 2 palatal folds. 



nitida, no. 3; philippii, no. 2. 



