Annotated checklist of the land snail fauna from southern Cambodia (Mollusca, Gastropoda) Author Sutcharit, Chirasak Animal Systematics Research Unit, Department of Biology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand Author Thach, Phanara Inland Fisheries Research and Development Institute (IFReDI), Fisheries Administration, No. 86, Norodom Blvd., PO Box 582, Phnom Penh, Cambodia https://orcid.org/0000-0002-3659-6577 Author Chhuoy, Samol Inland Fisheries Research and Development Institute (IFReDI), Fisheries Administration, No. 86, Norodom Blvd., PO Box 582, Phnom Penh, Cambodia Author Ngor, Peng Bun Inland Fisheries Research and Development Institute (IFReDI), Fisheries Administration, No. 86, Norodom Blvd., PO Box 582, Phnom Penh, Cambodia & Wonders of the Mekong Project, c / o IFReDI, No. 86, Norodom Blvd., PO Box 582, Phnom Penh, Cambodia Author Jeratthitikul, Ekgachai Animal Systematics and Molecular Ecology Laboratory, Department of Biology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand https://orcid.org/0000-0002-3477-9548 Author Siriwut, Warut Animal Systematics and Molecular Ecology Laboratory, Department of Biology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand Author Srisonchai, Ruttapon Department of Biology, Faculty of Science, Khon Kaen University, Khon Kaen 40002, Thailand Author Ng, Ting Hui Lee Kong Chian Natural History Museum, Faculty of Science, National University of Singapore, 2 Conservatory Drive, Singapore 117377, Republic of Singapore https://orcid.org/0000-0002-5123-0039 Author Pholyotha, Arthit Animal Systematics Research Unit, Department of Biology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand Author Jirapatrasilp, Parin Animal Systematics Research Unit, Department of Biology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand https://orcid.org/0000-0002-5591-6724 Author Panha, Somsak Animal Systematics Research Unit, Department of Biology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand somsak.pan@chula.ac.th text ZooKeys 2020 948 1 46 http://dx.doi.org/10.3897/zookeys.948.51671 journal article http://dx.doi.org/10.3897/zookeys.948.51671 1313-2970-948-1 20E7C61357714F328F6C44A7E84AFA68 52F291E3803D593EBF5741BFB13193FA Ganesella perakensis (Crosse, 1879) Figs 5C , 12A Helix (Geotrochus) perakensis Crosse, 1879: 199, 200, pl. 8, fig. 4. Type locality: Perak [Perak State, Malaysia]. Ganesella perakensis : Richardson 1985 : 130. Sutcharit et al. 2019a : fig. 4d. Material examined. Locality no. 15: CUMZ-CM159 (3 shells; Fig. 12A ), CUMZ-CM160 (2 shells), CUMZ-CM161 (3 specimens in ethanol; Fig. 5C ). The snails were found to live on tree trunks and leaves. Distribution. Peninsula Malaysia ( Sutcharit et al. 2019a ). Remarks. This species was originally described from Perak, Peninsula Malaysia, and a syntype was recently figured in Sutcharit et al. (2019a : fig. 4d). Characteristics of this species are its small shell size and trochoid shape. The whorls are slightly convex, with wide and shallow suture. The shell surface exhibits thin growth lines and thin corneous periostracum. The last whorl is with well-developed peripheral keel and blunt at lower periphery. The shell colour is pale yellow to brownish, with dark brown spiral bands on peripheral keel. The apertural lip is expanded, whitish, and angled. Ganesella perakensis belongs to the G. acris (Benson, 1859) species complex which is composed of 11 nominal species and widely distributed from Western Ghats of India to Indochina and the Greater Sunda Islands (see Richardson 1985 : 129, 130). However, G. perakensis differs from all species known in Indochina. It differs from G. subperakensis (Pilsbry, 1891) from "Tonquin" and G. vatheleti (Bavay & Dautzenberg, 1899) from "Van Bu, Tonkin" by having a strong peripheral keel. For comparison, G. subperakensis is convex below periphery, with less strong peripheral keel and without brownish spiral band ( Pilsbry 1891 ), while G. vatheleti exhibits a round last whorl and is more convex at base ( Bavay and Dautzenberg 1899 ). This species is very similar to G. lantenoisi (Dautzenberg & Fischer, 1906), which was described from Ha-Giang (Northern Vietnam) and Siam [Thailand]. The description itself was based mainly on the Ha-Giang specimen ( Dautzenberg and Fischer 1906 : pl. 9, fig. 10) while the Siamese specimen ( Dautzenberg and Fischer 1906 : pl. 9, fig. 11) is more similar to G. perakensis . Thus, the type series of this species seems to comprise of two separate species, one from northern Vietnam and one from Thailand. Ganesella perakensis differs from G. lantenoisi (specimen from Ha-Giang) in having a smaller shell (shell height up to 13 mm), shallow suture with 6 to 7 convex whorls, while G. lantenoisi performs an elongate trochoid, larger shell (shell height up to 18 mm), suture flattened and smooth 9 to 10 whorls. However, further investigations with both genitalia and DNA analysis will be necessary to elucidate the exact relationship between them.