The freshwater snails (Gastropoda) of Iran, with descriptions of two new genera and eight new species Author Gloeer, Peter Biodiversity Research Laboratory, Schulstrasse 3, D- 25491 Hetlingen, Germany Author Pesic, Vladimir Department of Biology, Faculty of Sciences, University of Montenegro, Cetinjski put b. b., 81000 Podgorica, Montenegro text ZooKeys 2012 2012-09-04 219 11 61 http://dx.doi.org/10.3897/zookeys.219.3406 journal article http://dx.doi.org/10.3897/zookeys.219.3406 1313-2970-219-11 35A0EBEF815740B5BE499DBD7B273918 FFE7FFDBAA3AFF8BF81AFFD7FFCDFF87 577535 Bithynia (Bithynia) mazandaranensis sp. n. Figs 7a-d Type locality. Mazandaran Province, Nowshahr city, pond near Caspian Sea, 51°31'E , 36°38'N , 18 June 2005. Holotype (ZMH 79369):Shell height 8.0 mm, width 5.0 mm. Etymology. Named after the region where the species was collected. Description. The horn-coloured shell is conical with 5.5 whorls, which are slightly convex with a clear suture and an acute apex. The umbilicus is closed. The aperture is ovate, angled at the top. The margin of the aperture is, from lateral view, sinuated. The surface bears a lattice structure. Shell height 8.0 mm, width 5.0 mm, aperture height 3.6 mm. Differentiating features. The new species resembles Bithynia tentaculata but differs from it by the following features: (i) the operculum is more angled ( Fig. 7c ), (ii) the whorls are more convex ( Fig. 7a-b ), and (iii) the surface has longitudinal and transverse striae ( Fig. 7d ). Associated species. Planorbis carinatus , Anisus sp., Valvata cristata , Valvata nowshahrensis sp. n., Hippeutis complanatus . Remarks. Probably this species formerly (e.g., Mansoorian 2000 ) was confused with Bithynia tentaculata . Because we had only an empty shell of this species, we do not know if it belongs to the genus Bithynia or Pseudobithynia , so our generic assignment is tentative. To address this question, anatomical studies of more specimens are necessary.