184 LAND REGIONS. 



genus Carinifex), Valvata, Ancylus, etc. Kamtschatka has six 

 terrestrial and seven fliiviatile species, three of the former, so 

 far, peculiar. 



The Amour territory, the North of China, Thibet and Turkestan, 

 although excluded from this region, contain a large percentage 

 of European forms. 



2. Mediterranean Region. 



All the countries bordering on the Mediterranean, the Black 

 and the Caspian Seas form a vast terrestrial region inhabited by 

 a very varied fauna. This region is limited by the African 

 desert, the Atlantic, the Alps, and to the east, by the Central 

 Asiatic region — with the species of which it intermingles in such 

 manner that certain authors consider the latter as a mere sub- 

 division. The immense development of the genus Clausilia is 

 characteristic of this region ; and in a less marked degree, the 

 number of species of Buliminus, Testacella, Daudebardia, Cal- 

 carina, Poriaatias. Certain sections of the Helices also are 

 hereunto restricted. Among the species distributed throughout 

 the entire province may be cited Bui. (Eumina) decoUata, Helix 

 ( Calcarina) candidissima,aperta,vermiculata, Pisana, variabilis^ 

 pyramidata^ acuta ^ Bidiviinus piqoa, Feruasacia folliculus, Physo, 

 {laidora) contorta, llelanopsis p7'aerosa, Unio littoi^alis, etc. 



Fischer thus sul)divides the region : 



a. Occidental or Atlantic Subregion. 



f Hispano-Barbaric Fauna. 



h. Meridional or Mediterranean J Egypto-S^^rian Fauna. 

 Subregion : including the 1 Hellado-Anatolic Fauna. 



[ Italo-Dalmatian Fauna. 



c. Central or Pontic Subregion. 



d. Oriental or Caspian Subregion. 



The first of these includes Portugal, North Spain and the 

 West of France ; it contains a number of characteristic forms, a 

 few of which extend bej-ond its boundaries. Some of these 

 species, however, are scarcelj^ entitled to be considered more 

 than varieties of mollusks having a more general distribution. 



In the Mediterranean subregion there are, as Fischer has 

 pointed out, several faunal provinces distinguished by character- 

 istic groups of related forms, evidently derived from a common 

 ancestry : such are the species of Helix belonging to the sections 

 Macularia and Calcarina, those of Melanopsis, etc. The genus 

 Clausilia is verj'' rare in Spain, and wanting in its southern portion. 

 In the Balearic Islands three-fourths of the species are Spanish, 

 the rest mostly peculiar — including several Helices of the section 

 Jacosta, only found there. 



The shells of Northern Africa are more closely related to 

 those of Spain than to those of Sicily, yet the ancient connection 



