1'LA>()1{1?1S, 123 



Alt. 1, diarn. maj. 2-GG, diaiii. niin. 2 (about) nun. 



]/((h. ^loradabad. 



Tlie figures and description given by .Sowerby iu Kecve's 

 ' Concliologia Iconiea,' vol. 20, and copied by Clessin in tlie 

 'Couchylien-Cabinet,' 18S5, obviously can liavc nothing to do 

 with Benson's species. 



247. Planorbis (Gyraulus) stelzneri (Dohrn). 



rianor/ns (Gi/ratdus) stehneri (Uohm). P. Z. S. 1858, p. 134; 



11. & T., C. I. pi. 91, tios. 4, 7 ; Clessin, in Conch.-Cab. 1884, 



p. 117, pi. II, tig-. 11. 



Orvjimd description: — Testa discoidea, albido-cornea, teiuiiter 



longitudiualiter striata, nitida, pellucida, supra plana, subrus i)aullo 



convexior, utriuque I'oveolata ; anfr. 3-4 vix couvexi, ultiuius 



acute carinatus ; apertura perobliqua, sublunaris ; ])eristoinium 



rectum, intus albolabiatum. 



Diain. maj. 7, diam. niin. "j-o nini. 

 Aperture : alt. I nun. 

 Hah. Ceylon, 



24S. Planorbis (? Gyraulus) hyptiocyclos {Benson). 



Planorbis (? Gyraulus) hi/ptioo/clos (Iknson), A. M. N. H. ser. 3, 

 xi, 1863, p. '89, & rfeilVer, Mou. lielic. v, p. 117 {as Heli.r) ; 

 11. & T,, C. I. pi. 99; Sowerbv in Reeve, Conch. Icon, xx, 

 pi. 14, fig. 120; Clessin, in Conch.-Cab. 1885, p. 228. 

 Orifjlnal description: — Testa latissinie umbilicata, orbiculato- 

 plauata, planorbiformi, depressa, fragili, oblique striatula, trans- 

 luceute, polita, olivaceo-cornea ; spira concaviuscula, apice foveo- 

 lato, suturis profundis ; anfr. 4|, gradatira incresceiitibus, 

 utrinque convexis, ultimo convexiusculo, peripberia subcarinata ; 

 apertura valde obliqua, elliptieo-hinata ; peristomate tenui, aruto, 

 margiiiibus couniventibus, callo tenui junctis. 

 Alt. 1-5, diam. maj. 0, diam. min, 5 mm. 

 Hah. Fort MacDoiiald, Ceylon (Province of Uva) {F. Liujard). 



Clessin (jS'achr. Bl, Malak. Ges. sxxix, 1907, p. 7) reports 

 PI. (Tropidiscus) marrjinatus, Drap. xav. sidmiarginatus, Jan, and 

 PI. (T.) carinatus, Miill. from the Pamirs, together with the 

 following two species described by him at the same time, 

 without figures. 



24!). Planorbis (Gyraulus) acutus, Clessin. 



Planarhis {Gijraulm) acutus, Clessin. Xachv. Bl. ^Malak. Ges, 

 xxxix, 1007, p. 7. 



Shell flattened, whorls 4, very rapidly increasing, the lasl one- 

 third of the total diameter of the shell, whorls very compressed, 

 in section almost lancet-shaped ; sharply keeled, more convex 

 above the keel than below; suture slightly impressed; finely 

 sculptUi-ed ; umbilicus wide ; aperture very oblique, compressedly 

 ovate. 



Alt. 1-5, diam. 7 mm. 



Hah. Pamirs, numerous but very local. 



