X THE PONTIC PROVINCE 295 



regions of the north, are much more varied and numerous than 

 those of Egypt. Clausilia is again fairly plentiful, and the 

 Helicidae are represented by some striking 

 forms of the sections Levantina, Pomatia^ 

 and Nummulina. Leucochroa has several 

 curious types with a constricted aperture, 

 and the Agnatha are represented by Lihania^ 

 a peculiar form of Daudehardia. A promi- 

 nent feature is the occurrence of a number 

 of large white Buliminus of the Petraeus 

 section (Fig. 200). Land operculates appear 

 to be absent, but Melanopsis and Neritina ^^^-^^^o.- A Buliminus 



' -L {Petraeus) labrosus 



are abundant. The Dead Sea contains no oiiv., Beyrout ; b, 

 Mollusca, but Lake Tiberias has a rich fauna, ^^^f'^^^^^ (Ghond- 



' ' rula) septemdentatus 



including the above-mentioned genera, with Roth., Palestine. 

 a Corhieula and several Unio. 



Upper Mesopotamia appears to possess a mixture of Syrian 

 and Caucasian forms, including a Parmacella. Lower Mesopo- 

 tamia has an exceedingly poor land fauna, but is comparatively 

 rich in fresh- water species, the growing eastern character of 

 which is shown by the occurrence of several Corhieula and 

 Pseudodon, and of a Neritina of a distinctly Indian type. 



(5) The Pontic province extends from Western Austria to 

 the Sea of Azof, and includes Austria, Hungar}^ Roumania, the 

 Balkan peninsula (so far as it does not form part of the Mediter- 

 ranean sub-region), the islands of the Greek Archipelago, south- 

 ern Russia and the Crimea, and Asia Minor. It thus practically 

 corresponds to the whole Danube basin, together with the lands 

 bordering on the Black Sea, except at the extreme east, which 

 belongs to the Caucasian sub-region. Fischer separates off 

 Greece, Asia Minor (except the northern coast-line), and the 

 intervening islands, with Crete and Cyprus, as constituting a 

 portion (Hellado-Anatolic) of the Mediterranean sub-region 

 proper. These districts, however, appear to possess scarcely 

 sufficient individuality to warrant their separate consideration. 



A prominent characteristic of the Pontic Mollusca is the 

 great abundance of Clausilia and Buliminus. In the islands 

 east and west of Greece Clausilia forms a large proportion of the 

 fauna, each island, however small, possessing its own peculiar 

 forms. The Helices belong principally to the groups Campylaea 



