92 MANTJAI, OF THE MOLLUSCA. 



SjTia, having become extinct in the intervening countries. Two 

 species of LithogJi/pJms inhabit the Danube; Cyrena {Corhicula) 

 Panormitana is found in Sicily, two others in the Euphrates, 

 and C. consohrina in the Alexandrian Canal, 



The Lusitanian province includes numerous minor regions, 

 the islands and mountain tracts especially being centres or foci 

 where a number of peculiar species are associated with thoso 

 living around. Thus, of species not as yet recorded from other 

 localities, Switzerland has 28, the Austrian Alps 46, Carpa- 

 thians 28, North Italy and Dalnlatia 100, Eoumelia 20, Greece 

 and its Archipelago 90, Anatolia 50, Caucasia 20, Syria 30, 

 Lower Egj'pt and Algeria 60, Spain 26, and Portugal 15 

 Ilehcidce and 9 Limacidce. 



Mediterranean Islands. 



Corfu, Cyprus, Ehodes, Syra, Candia, and Crete, have each a 

 few peculiar land-snails, amounting to 40 species altogether. 



Bcdearic Isles. — Helix Graellsiana, hispanica (var. balerica), 

 nyellii, minoricensis ; and Cyclostoma ferrugineum, common to 

 Spain and Algeria. 



Corsica. — Helix Easpaili, tristis, Clausilia 4 sp. 



Sardinia. — Helix Sardiensis, meda, tenui-costata, Pupa 2, 

 Clausilia 1. 



Malta has 2 peculiar species of Helix, and a Clausilia (scalaris). 



Sicily has 40 peculiar species of Helices and 3 Limaces. This 

 island is connected with North Africa by a winding shoal with 

 deep water on each side. 



Madeira Group. 



These ancient volcanic islands, 660 miles south-west of Por- 

 tugal, consist of Madeira, with Fora and three other islets called 

 Bezertas, and Porto Santo, 26 miles to the north-east, with the 

 rocky islets Ferro, Baxo, and Cima.* The land-snails have 

 been described by the Eev. E. T. Lowe,t and form the sub- 

 ject of a monograph by Dr. Albers.| The investigations of 

 Mr. Yemen Wollaston have nearly doubled the number of 

 known species, which now amount to 134. The Vitrince belong 



* These islands, and also tlis Canaries and Azores, contain marine fonnations 

 (volcanic grits and tufas) -vritJi Miocene Tertiary shells. The islet of Baxo is quarried 

 for lime. 



t Piimitiee et novitise Faunae et Flora Mnderse et Portus Sancti. 12mo. Lond., 1851' 

 Descriptive list of all the species, by same author, Zool. Proc. for 1854, p. 161. The 

 statements and numbers given above are taken from this last monograph, coiTected bv 

 Mr, Wollaston. 



t Malacographia Maderensis, 4to. Berlin, 1854, with fl<?ure» of »1I the species. 



