314 



THE PHILIPPINES 



Fig. 212.— Helix (Obbina) rota Brod., 

 Pliilipjiines. 



Other forms peculiar to the Philippines are Diaplwra, a 



section of Ennea with a curi- 

 ously produced mouth, and 

 several sub-genera of the 

 ^ Naninidae(F*^?'imco7iws, Vit- 

 rinoidea, Hemitrichia). The 

 great Mhysota here find their 

 metropolis. Another very 

 marked group of Helix is 

 Ohhina, 19 of the 25 known 

 species being peculiar. 

 The Helicidae proper of the Philippines are still held in 

 check, as in the greater part of the Indian region, by the 

 Naninidae. The single I'rachia and Plectotropis, and the 2 

 species each of Plectopylis and Satsuma, indicate aftinities with 

 Indo-China. Further important Indian relationships are seen 

 in the great Nanina and Cyelo-pliorus, which here attain almost 

 Indian dimensions; in Kaliella (8 sp.), Sitala (2), Clausilia 

 (1). Among the operculates we still have 1 Alycaeus and 1 

 Coptochilus. Singularly enough, several Indian genera which 

 occur here are not found in the intervening islands of Borneo, 

 Sumatra, or Java, e.g. Streptaxis, Hypselo stoma, Ditropis, Acmella, 

 and Gyatliopoma. The curiously tubed Malay operculates, 

 Opistlwporus , etc., fail to reach the Philippines proper, although 

 occurring in Borneo and N. Celebes ; one of them reaches Palawan. 

 The strikingly Malay genus Amphidromus reaches Palawan, but 

 no farther (1 sp.), while 2 species reach Mindanao, and one of 

 these penetrates as far as Bohol and S. Leyte. Amongst the 

 slugs, Mariaella occurs again only in the Seychelles, and Tennentia 

 only in Ceylon. 



Land and Fresh-ioater Mollusca of the Philippines 



