Genus-level revision of the Alycaeidae (Gastropoda, Cyclophoroidea), with an annotated species catalogue Author Pall-Gergely, Barna Plant Protection Institute, Centre for Agricultural Research, Herman Otto ut 15, Budapest, H- 1022, Hungary https://orcid.org/0000-0002-6167-7221 pallgergely2@gmail.com Author Sajan, Sheikh Zoological Survey of India, Prani Vigyan Bhawan, M Block, New Alipore, Kolkata 700053, West Bengal, India & Wildlife Institute of India, Chandrabani, Dehradun 248 002, Uttarakhand, India https://orcid.org/0000-0002-2785-6824 Author Tripathy, Basudev Zoological Survey of India, Prani Vigyan Bhawan, M Block, New Alipore, Kolkata 700053, West Bengal, India Author Meng, Kaibaryer National Zoological Museum of China, Institute of Zoology, Chinese Academy of Sciences, Beijing, China Author Asami, Takahiro Department of Biology, Shinshu University, Matsumoto 390 - 8621, Japan https://orcid.org/0000-0001-5706-0272 Author Ablett, Jonathan D. Mollusca Section, Invertebrates Division, Department of Life Sciences, The Natural History Museums, London SW 7 5 BD, United Kingdom text ZooKeys 2020 981 1 220 http://dx.doi.org/10.3897/zookeys.981.53583 journal article http://dx.doi.org/10.3897/zookeys.981.53583 1313-2970-981-1 5194AAC86B8A473F8A41470A60182A0B 7C44C797C4125A71BAE032A55E6FA5DC Metalycaeus nipponensis (Reinhardt, 1877) Fig. 31A Alycaeus Nipponensis Reinhardt, 1877: 68. Alycaeus nipponensis - Pilsbry 1900 : 381. Alycaeus melanopoma Pilsbry, 1900: 382. Alycaeus (Chamalycaeus) nipponensis - Kobelt 1902 : 360. Alycaeus (Metalycaeus) melanopoma - Kobelt 1902 : 378. Chamalycaeus (Chamalycaeus) nipponensis - Zilch 1957 : 144, pl. 5, fig. 16. Chamalycaeus nipponensis - Azuma 1982 : 11, pl. 4, fig. 35; Minato 1988 : 13. Chamalycaeus (Metalycaeus) nipponensis - Egorov 2013 : 37, figs 67a, b. Metalycaeus nipponensis - Pall-Gergely et al. 2017 : 73, figs 46A-C; Pall-Gergely and Asami 2017 : 4. Type locality. "Kioto" . Material examined. Hakone Mts, Japan, leg. Schmacker, ANSP 78815 (lectotype of A. melanopoma , designated by Baker 1964 , photographs examined); Japan, Yedo, Doenitz l., coll. Reinhardt, SMF 185407 (labelled as 'typus' ); 東京都 (Tōkyō-to), 多摩市 (Tama-shi), 蓮光寺聖跡記念館 境内 (Renkō-ji Seiseki Kinenkan keidai) [Tama City, Tokyo Metropolitan Prefecture], NSMT-Mo 79102 (91 shells). Remarks. Protoconch elevated, its last 0.5 whorl with spiral lines; ribbing on R2 is quite variable; there are 14-22, usually elevated and distinct ribs. In some specimens the ribs are relatively irregular, and they seemingly join to each other near the tube. This is, however, rather due to the fact that the shells are weathered (despite the fact that they were collected alive), because the elevated ribs are destroyed and appear lower. R1 with clearly visible, fine spiral striation. In the examined sample, 91 specimens had an operculum, and of those 53 of them had the outer black circle present. In case of 27 specimens the outer circle was entirely missing, and in 11 cases only small fragments of the rings remained.