32 Dr. Cantor on the Flora and Fauna of Chusan. 



valde prominente, semicirculari, inferiori recedente, recto. Diam. 0*4 

 poU. 



Habitat. Canals, ponds, attached to Chara. 



*Planorbis hemisphosrula. Testa nitida, olivaceo-coruea, supra 

 convexa, apice planulata, infra excavata, umbilico coarctato, peri- 

 pheria obtusa, nullo modo carinata. Diam. 0*25 poll. 



Habitat. Same localities as P. papyraceus on Chara and Lemna. 



Planorbis compressus, Hutton. 



Habitat. Same localities as the preceding. Inhabits also Bengal. 



*Lr/mncea plicatula. Testa elongato-ovata, cornea, scabriuscula ; 

 anfractu ultimo transverse plicatula, suturis impressis ; spira medio- 

 cri, apice acuto plerumque ferrugineo ; apertura infra patulante, basi 

 evasa. 



Habitat. Ponds. 



*Lymn(ea minor. Testa ovato-acuta, cornea, polita ; spira vix di- 

 midium testae efFormante, apice obtusiusculo ; anfractibusquatuor, su- 

 turis leviter impressis ; apertura ovata, plica columellse obsoleta. 



Habitat. Same locality as the latter. 



Tectibranchiata. 



*Bull(ea caurina. Testa ovato-oblonga, alba, tenuissima, papyracea, 

 transverse eleganter minutissimeque striatula ; apertura auriformi 

 supra angustata, infra patulante ; labro apicem superante ; spira 

 nulla. 



Habitat. Said to inhabit canals. 



Pectinibranchiata . 



*Paludina quadrata. Testa elongato-conoidea, crassa, epidermide 

 viridi-olivacea, anfractibus sex planulatis, leviter transverse plicatis, 

 longitudinaliter liratis ; liris subquinis ; apertura mediocri, intils al- 

 bida violacea ; umbilico arcto, peritremate nigrescente. 



Habitat. Canals and ponds. 



*Paludina lecythoides. Testa ovato-acuta, olivacea, anfractibus 

 sex aut septem rotundatis, transverse subplicatis ; suturis excavatis ; 

 apertura oblonga, peritremate subreflexo, nigro; apice acuto; umbi- 

 lico setate evanescente. 



Habitat. Ditches and ponds. 



*Paludina (Bithynia, Gray) longicornis . Testa ovato-conoidea, 

 cornea, polita, spira aperturam longitudine vix superante ; anfrac- 

 tibus quatuor, ultimo convexo, suturis minime depressis ; apertura 

 subrotunda, supra angulata ; peristomate subreflexo, nigrescente ; 

 labio crassissimo ; operculo testaceo, umbilico evanido ; apice ob- 

 tuso. 



Habitat. In canals, attached to aquatic plants, stones, piles. 



*Paludina (Bithynia) striatula. Testa ovato-acuta, cornea, polita ; 

 spira elongata ; anfractibus quinque convexiusculis, liris pluribus, in- 

 terdum inconspicuis, circumdatis ; suturis depressiusculis ; apice ob- 

 tusato ; peristomate reflexo nigrescenti, undato ; umbilico evanido ; 

 operculo calcareo. 



Habitat. Same localities as the latter. 



