PHYSID.E. 127 



258. Planorbis (Segmentina) calathus (Benson). 



Planorbis (Segmentina) calathus (Benson), A. M. N. II. ser. 2, v, 

 1850, p. 348; II. & T., C. I. pi. 34, figs. 1-3; Sowerby, in 

 Reeve, Conch. Icon, xx, pi. 4, fig. 30; Clessin in Conch.-Cab. 

 1884, p. 136, pi. 15, fi-. 13. 



Original description: Testa nitidiuscula, albido-cornea, vel 

 lutescente cornea, subdiaphana, exiliter radiato-striata, supra con- 

 vexa, versus apicem plunulata, apice concavo, sutura impressa ; 

 anfr. 4, ultimo extus depresso, inferne angulato, intus laminis 

 denticulisque radiatis frequentioribus munito, subtus subplanato, 

 versus umbilicum angustum, profunduin excavate ; apertura 

 obliqna, cordato sagittata intus remote labiata, margins superior! 

 arcuato, prominente, inferior! subrecto, recedente. 



Alt. 2, diara. maj. 4-66, diam. min. 4 mm. 



Hab. Bhimtal and Neini Tal, in tbe Kemaon Eegion of the 

 Himalayas; Moradabad ; Kattiawar ; Ceylon; Kashmir, etc. 



Apparently very local, but abundant where fouud. 



259. Planorbis (Segmentina) caenosus (Benson). 



Planorbis (Segmentina) ceenosus (Benson), A. M. N. H. ser. 2, v, 

 1850, p. 349; H. & T., C. 1. pi. 39, figs. 7, 8; Sowerby, in 

 Reeve, Conch. Icon, xx, pi. 10, fig. 78; Clessin, in Conch.-Cab. 

 1884, p. 165, pi. 24, fig. 4. 



Original description : Testa nitida, luteo-cornea vel olivaceo- 

 t:oriiea, oblique et rude (praecipue subtus) radiato-striata, sub- 

 diaphana, supra depresso-convexa ; spira parvula, apice excavato ; 

 sutura impressa; anfr. 3J, ultimo majori, extus depressiusculo, 

 inferne carinato, subtus planato, versus umbilicum majorem 

 leviter excavato ; apertura obliqua, sagittiformi, margine superior! 

 arcuato, prominente inferior! recedente, recto. 



Alt. 1'5, diam. maj. 6, diam. min. 5 mm. 



Hab. Moradabad ; Ceylon. 



Differing from P. (S.) calathus in having no internal laminas and 

 in being more depressed and more angular at the keel ; moreover 

 tbe relative dimensions are not the same. 



Family PHYSID^. 



Subfamily PHYSIN^. 



Shell fusiform or ovately fusiform, sinistral, horny. 

 Distribution. World- wide. 



Genus PHYSA. 



Physa, Draparnaud, Tabl. Moll. France, 1801, p. 52, & Hist. Nat. 

 Moll. Terr. Fluv. France, p. 54. 



