100 MANUAL OF THE MOLLUSCA. 



few of tlie Indian species are common to China and the Asiatic 

 Islands, or even to Ceylon. The shells of northern India 

 resemble those of the Lusitanian region ; in the south they 

 approximate more to the large and vividly coloured species of 

 the Asiatic Islands. In the Himalaya land shells are numerous, 

 and ascend as high as the region of Junipers and Ehododen- 

 drons, 4,000—10,000 feet above the sea. 



Helix 83 Pupa 7 Cyclophorua 26 



Nanina 46 Clausilia 7 Leptopoma 1 



Ariophanta 8 Vitrina 9 Pterocyclus 10 



Streptaxis 3 Succinea 7 Cyclotus 3 



Bulimus ...45 Parmaoella 2 Megalomastoma 4 



Achatina 16 Cyclostoma 3 Diplommatina 3 



Parmacella and Vaginulus are found in India, and the typical 

 fresh-water species of Oncidium. Ordinary forms of Limncea 

 and Flanorhis are abundant, and there is one species of AncyJus. 

 Physa occurs only in a fossil state, or is represented by the 

 singular Camptoceras of Benson. Hypostoma Boysii, Auricula 

 Judce, and Polydonta scarahceus are also Indian forms. 



The gill-breathing fresh-water shells of India are very 

 numerous, especially the Melanias and Melanatrias, and species 

 oiPirena, Paludomus, Hemimitra (retusa), Ampullaria, Paludina, 

 Pithy nia, Nematura (deltse), Assiminea (fasciata), Neritina (par- 

 ticularly crepidularia and Smithii) and Navicella (tessellata). 



The brackish-water species of Cerithidium, Terehralia, and 

 Pyrazus are mostly common to India and North Australia. 



The fresh-water bivalves are a few ordinary forms of Unio, 

 3 species of Cyrena, a Corhicula (of which 6 species have been 

 made), Cydas Indica, Area scaphula, Olaucomya cerea, and Nova- 

 culina gangetica, 



Ceylon. The land-shells of Ceylon have been investigated by 

 Mr. Benson ; they most resemble those of the Neilgherry hills, 

 but are nearly all specifically distinct, and even some of the 

 genera are peculiar. It seems entitled to rank as a province. 

 Helix Waltoni and Skinneri, are examples of the most charac- 

 teristic form of Helices ; the Vitrini-form type {Nanina) is also 

 common. H. hcemastoma, one of the most conspicuous species, 

 found on trees at P. Galle, is common to the Nicobar Islands. 

 The Achatinas belong to a distinct section [Leptinaria, Beck), 

 also represented on the Continent. Some of the Bulimi approach 

 the Philippine forms. 



Helix 46 Succinea I Pterocyclus 5 



Nanina 9 Pupa „. 3 Aulopoma 4 



Vitrina 3 Achatina 8 Leptopoma 6 



Streptaxis 2 Cyclophorus 12 Cataulus 10 



Bulinaus 13 



