t^^l

PLAXORBIS. 123
Alt. 1, diaiu. maj. 2-66, diam. iniii. 2 (about) mm.
JIah. Moradabad.
The figures and description given by Sowerby in Eecve's
' Conchologia Iconica,' vol. 20, and copied b}' Clessin in the
' Concbylien-Cabinet,' 1885, obviously can have nothing to do
with Benson's species.
247. Planorbis (Gyraulus) stelzneri (DoJmi).
Planorbis {Oyrmdus) stelzneri (TJolu-n), P. Z. S. 1858, p. 134;
H. & T., C. I. pi. 91, figs. 4, 7; Clessin, in Concb.-Cab. 1884,
p. 117, pi. 11, fig. 11.
Original description:—Testa discoidea, albido-cornea, tenuiter
longitudinaliter striata, nitida, pellucida, supra plana, subtus pauUo
convexior, utrinque foveolata; anfr. 3-4 vix con\ex\, nltiinus
acute carinatus ; apertura perobliqua, sublunaris; peiistomiuni
rectum, intus albolabiatum.
Diam. maj. 7, diam. min. 5-5 mm.
Aperture : alt. 1 mm.
Hah. Ceylon.
248. Planorbis (? Gyraulus) hyptiocyclos {Benson).
Planorbis (? Gyraulus) lit/ptiocyclos (Benson), A. M. N, H. ser. .3,
xi, 1863, p.'89, &rfeiflei-, Mou. Holic. v, p. 117 {as Heli.v) ;
H. & T., C. I. pi. 99; Sowerbv in Reeve, Conch. Icon, xx,
pi. 14, fig. 120; Clessin, in Conoii.-Cab. 1885, p. 228.
Original description:—Testa latissirae umbilicata, orbiculatoplauata,
plaiiorbit'orini, depressa, fragili, oblique striatula, transluceute,
polita, olivaceo-cornea ; spira concaviuscula, apice foveolato,
euturis profundis; anfr. 4|, gradatim inerescentibus,
utrinque convexis, ultimo convexiusculo, peripberia subearinata;
apertura valde obliqua, elliptieo-lunata ; peristomate tenui, acuto,
marginibus conniventibus, callo tenui junctis.
Alt. 15, diam. maj. 6, diam. min. 5 ram.
Hah. Port MacDonald, Ceylon (Province of Uva) {F. Layard).
Clessin (K"achr. Bl. Malak. Ges. xxxix, 1907, p. 7) reports
PI. (Tropidiscus) marginatiis, Drap. var. suhmarginatus, Jan, and
PI. {T.) carinatus, Miill. from the Pamirs, together with the
following two species described by him at the same time,
without figures.
249. Planorbis (Gyraulus) acutus, Clessin.
Planorbis {Gyraulus) acutus, Clessin, Nachr. BL Malalr. Ges.
xxxix, 1907, p. 7.
Shell flattened, whorls 4, very rapidly increasing, the last onethird
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
sculptured ; umbilicus wide; aperture very oblique, compressedly
ovate.
Ait. 1"5, diam. 7 mm.
Hah. Pamirs, numerous but very local.