74 PULMON'ATA, 



Nanina (retrorsa) has very many teeth in a slightly doubly 

 curved hne ; the central tooth is simple ; the central lateral teeth 

 have a broad double base ; the more external ones (the change is 

 gradual) have a nan'ow double base, each of the lobes being 

 bifid :— see Troschel, Wiegm. Arch. xv. (1849) 236. t. 4. f. 6. 

 The upper jaw is simple, arched, entire. 



Dr. Albers divides this genus into four, with the following 

 characters : — 



1. Xesta. Shell smooth, polished — N. citrina. 



2. Microcystis. Shell smallish, ver}' smooth ; mouth broad, 

 subvertical — N. orbis. 



3. Hemiplecta. Shell above granular or decussate striated, 

 beneath polished, last whorl more or less keeled — -A^ bulla. 



4. Ryssota. Shell above rugose-striate, beneath polished, last 

 whorl depressed, dilated in front — JV. Sowerbyana. 



a. Continental India. 



1. Nanina nana. 



Shell rather small, convex-conoidal, pale brownish ; whorls 

 six to seven, closely convoluted, the last rounded ; apertiu-e ra- 

 ther wide ; lip simple ; umbihcus evanescent ; apex ver}" obtuse. 

 Lat. 01 poll. 



Helix nana, Hutton, Journ. As. Soc. vii. 218. pt. 1. 

 Pfr. Mon. Helic. i. 31. 



Hab. Simla, Himalaya. 



2. Nanina cacuminifera. 



Shell with a covered umbihcus, conic, trochiform, hom-co- 

 loured ; spire attenuated towards the blunt, nipple-shaped apex ; 

 whorls eight, slowly increasing, flattened above and marked 

 with seven spiral, minutely granulate lines, with more minute 

 similar intermediate ones ; last whorl acutely compressed and 

 keeled, convex, polished and with radiating striae beneath ; aper- 

 ture securiform ; peristome sharp, with the lip scarcely dilated 

 and reflected above. Height 10, greatest breadth 19, least 

 breadth 16 mill. 



Helix cacuminifera, Benson, in Ann. and Mag. Nat. Hist. 1850, 

 arch, 214. 



Reeve, n. 744. t. 124. 

 Pfr. Mon. Suppl. 36. 



Hab. Neilgherries {Jerdon). 



