PLA^OKBIS. 123 



Alt. 1, diam. maj. 2-66, diam. min. 2 (about) mm. 



Nab. Moradabad. 



The figures and description given by Soxverby in Reeve's 

 ' Conch ologia Iconica,' vol. 20, and copied by Clessin in the 

 ' Conchylien-Cabinet,' 1885, obviously can have nothing to do 

 with Benson's species. 



247. Planorbis (Gyraulus) stelzneri (Dolirri). 



Planorbis (Guraulus} stelzneri (Dohrn), P. Z. S. 1858, p. 134; 

 H. &T., C. J. pi. 91, figs. 4, 7; Clessin, in Conch.-Cab. 1884, 

 p. 117, pi. 11, tig. 11. 



Original description: Testa discoidea, albido-cornea, tenuiter 

 longitudinaliter striata, nitida, pellucida, supra plana, subtus paullo 

 convexior, utrinque foveolata ; anfr. 3-4 vix convexi, ultimus 

 acute carinatus ; apertura perobliqua, sublunaris ; peristomium 

 rectum, intus albolabiatum. 



Diam. maj. 7, diam. min. 5-5 mm. 



Aperture : alt. 1 ram. 



Hob. Ceylon. 



248. Planorbis (? Gyraulus) hyptiocyclos (Benson}. 



Planorbis (? Gyraulus) hi/ptiocyclos (Benson), A. M. N. H. ser. 3, 

 xi, 1863, p. 89, & Pfeiffer, Mou. Helic. v, p. 117 (as Helix) ; 

 H. & T., C. I. pi. 99; Sowerby in Reeve, Conch. Icon, xx, 

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



Original description: Testa latissime umbilicata, orbiculato- 

 planata, planorbit'ormi, depressa, fragili, oblique striatula, trans - 

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

 lato, suturis profundis ; anfr. 4|, gradatim increscentibus, 

 utrinque convexis, ultimo convexiusculo, peripheria subcarinata ; 

 apertura valde obliqua, elliptico-lunata; peristomate tenui, acuto, 

 marginibus conniventibus, callo tenui junctis. 



Alt. 1:5, diam. maj. 6, diaoi. min. 5 mm. 



Hab. Fort MacDonald, Ceylon (Province of Uva) (F. Layard). 



Clessin (Xachr. Bl. Malak. Ges. xxxix, 1907, p. 7) reports 

 PI. (Tropidiscus) marginatus, Drap. var. submaryinatus, Jan, and 

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

 following txvo species described by him at the same time, 

 without figures. 



249. Planorbis (Gyraulus) acutus, Clessin. 



Planorbis (Gyraulus) acutus, Clessin, Nachr. Bl. Malak. Ges. 

 xxxix, 1907, p. 7. 



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

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

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

 above the keel than below; suture slightly impressed; finely 

 sculptured ; umbilicus wide ; aperture very oblique, compressedly 

 ovate. 



Alt. 1-5, diam. 7 mm. 



Hab. Pamirs, numerous but very local. 



