INDIAN REGION. 393 



approximate more to the large aud vividly coloured species of the Asiatic 

 Islands. In the Himalaya land shells are numerous, and ascend as high as 

 the region of Junipers and Rhododendron?, 4,000 — 10^000 feet above the sea. 



Helix 37 Pupa 7 Cyclophorus 2(5 



Naniua 46 Claiisilia 7 Leptopoma 1 



Ariophanta 8 Vitrina 9 Pterocyclua 10 



Streptaxis.. 3 Succiuea 7 Cyclotus 3 



Bulimus 40 Parmacella 2 Megalomastoma 4 



Achatina 13 Cycloatoma 3 Diplommatina 3 



Parmacella and Vaginulus are found in India, and the typical fresh-water 

 species of Oncidium. Ordinary forms of Limncea and Flanorb'is are abun- 

 dant, and there is one s])ecies of Ancylus. Physa occurs only in a fossil state 

 or is represented by the singular Camftoceras of Benson. Hypostoma Boysii^ 

 Auricula Judce and Poli/donta scarabcsus are also Indian forms. 



The gill-breathing fresh-water shells of India are very numerous, especially 

 the Melauias and Melanatrias, and species of Pirena, Paludomus, Hemimi- 

 tra (retusa), Ampullaria^ Paludina, Bitht/nia, Nematura (deltee), Assiminea 

 (fasciata), Neritina (particularly crepidularia and Smithii) and Navicella 

 (tessellata). 



The brackish- water species of Cerithidium, Terebralia^ and Pyrazus are 

 mostly common to India and North Australia. 



The fresh-water bivalves are a few ordinary forms of JJnio, 3 species of 

 Ci/rena,?L Corbicula {of -which 6 species have been made), Cyclas Indica, 

 Area scaphula, Glaucoviya cerea and Kocaculina gangetica<. 



Ceylon. — The laud-shells of Ceylon have been investigated by Mr. Benson 

 who has favoured us with a list of 112 species ; 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. Eelix 

 Waltoni and Skinneri, are examples of the most characteristic form of Helices, 

 the Vitrini-form type {Nanina) is also common. H. hamastoma, one of the 

 most conspicuous species, found on trees at P. Galle, is common to the Nico- 

 bar Islands. The x\.chatiua3 belong to a distinct section {Leptiuaria, Beck) 

 also represented on the Continent. Some of the BuUmi approach the Philip- 

 pine forms. 



Helix 36 Succinea 1 Pterocyclus 5 



Nanina^ 'J Pupa 3 Aulopoma 4 



Vitrina . i 3 Achatina 7 Leptopoma 7 



Streptaxis 2 Cyclopliorus 12 Cataulus 10 



Bulimus 11 



The fresh-water shells belong to the genera Limnsea, Physa, 2 species, 

 (not found on the Continent) ; Planorbis, Melauia, Tanalia 10 (peculiar), 

 Paludomus, Bithynia, Ampullaria, Neritina, Navicella, Unio, and Cyrena. 



At the Nicobar Islands are found — Cataulus tortuosus, Helicina Nicoba- 

 rica and Pupina Nifiobarica. Helix castanea is from Sumatra. {Beck), 



