296 THE CAUCASUS AND THE CASPIAN SEA chap. 



(which is very abundant in Austro-Hnngary), Pomatia (Greece 

 and Asia Minor), and Anchistoma. Macularia is comparatively 

 scarce, but is represented in Greece by one very large form 

 {Codringtonii Gray). Zonites proper has its metropolis in this 

 sub-region, and the Danube basin contains one or two species of 

 Melania and Lithoglyphus. Buliminiis is abundant throughout 

 the sub-region, in the sub-genera Zebrina, Naipaeus, Mastus, and 

 Chondrula. Several striking forms of Zebrina {Ena) are peculiar 

 to the Crimea. 



(c) The Caucasian Province. — The limits of this province 

 can hardly be exactly defined at present. It appears, however, 

 to include the whole line of the Caucasus range, Armenia, and 

 North Persia. 



The land MoUusca are abundant and interesting. Among 

 the carnivorous genera are four species of Daudehardia, a Glandina, 

 and three peculiar forms of naked slug, Pseudomilax, Trigono- 

 chlamys, and Selcnochlamys. There is a single Parmacella, the 

 same species as the Mesopotamian, and a good many forms of 

 Limax. Vitrina and Hyalinia are well represented, and the pre- 

 dominant groups of Helix are Eulota, Cartusiana, Xerophila, and 

 Fruticocampylaea, the last being peculiar. Clausilia and Pupa 

 are rich in species, together with Bidiminus of the Chondrula 

 tjrpe. One Clausilia of the Phaedusa section, together with a 

 Macrochlamys (Transcaspian only), a Corbicula, and a Cyclohis, 

 show marked traces of Asiatic affinity. There is one species each 

 of Acicula and Gyclostoma, and one of Pomatias. 



The Caspian Sea, like Lakes Baikal and Tanganyika, is dis- 

 tinguished by the possession of several remarkable and peculiar 

 genera. The sea itself, the waters of which are brackish, is 80 

 feet below the level of the Black Sea, and is no doubt a relict of 

 what formed, in earlier times, a very much larger expanse of 

 water. Marine deposits containing fauna now characteristic of 

 the Caspian, have been found as far north as the Samara bend of 

 the Volga. It is probable, therefore, that in Post-pliocene times 

 an arm of the Aralo-Caspian Sea penetrated northward up the 

 present basin of the Volga to at least 54° N. The Kazan 

 depression of the Volga (55° N.) also contains characteristic 

 Caspian fossils.^ According to Brusina," the Caspian fauna, 



^ Netchayeft', Kazan Soc. Nat. xvii. fasc. 5. 

 ' Fauna der Conge7-ie7i-Schichtcn, p. 142. 



