Integrative taxonomy of the genus Onchidium Buchannan, 1800 (Mollusca, Gastropoda, Pulmonata, Onchidiidae) Author Dayrat, Benoit Author Goulding, Tricia C. Author Apte, Deepak Author Bhave, Vishal Author Joseph Comendador, Author Qua, ng, Ngo Xuan Author Tan, Siong Kiat Author Tan, Shau Hwai text ZooKeys 2016 636 1 40 http://dx.doi.org/10.3897/zookeys.636.8879 journal article http://dx.doi.org/10.3897/zookeys.636.8879 1313-2970-636-1 55CD34169B9040DDA34A2026640E1E83 Genus Onchidium Buchannan, 1800 Type species. Onchidium typhae Buchannan, 1800, by monotypy. Labella Starobogatov, 1976: 211. New synonym. Type species, by monotypy, Labella ajuthiae ( Labbe , 1935); replacement name of Elophilus Labbe , 1935, preoccupied by Elophilus Meigen, 1803 [ Diptera ]. Remarks. The synonymy of Labella ajuthiae ( Labbe , 1935) with Onchidium stuxbergi (Westerlund, 1883) is discussed in the remarks on Onchidium stuxbergi . Labella is a junior synonym of Onchidium because the two generic names Labella and Onchidium apply to the same clade. Baker (1938) provided a list of misspellings and unjustified emendations of Onchidium : Onchidion , Onchydium , Orchidium , and Oncidium . Diagnosis. Body not flattened. No marginal glands in the notum. No dorsal gills. Dorsal eyes present on notum. Fully retractable, central papilla (with three dorsal eyes) present. Long eye tentacles. Male opening inferior to the right ocular tentacle, slightly to its left. Pneumostome medial. Intestine of types II and III. Rectal gland present. Accessory penial gland and hollow spine present. Penis with hooks. Distinctive diagnostic features. Onchidium differs from all other onchidiids by the presence of unmistakably, large, conical, pointed papillae on the dorsum of live animals. Disturbed live animals and preserved animals are retracted and their dorsal papillae are significantly smaller. The identification to the genus level can then be more challenging. Distribution. From north-eastern India (West Bengal) to the Philippines, including the Strait of Malacca, Singapore, Thailand, Vietnam, eastern Borneo, and China (Fig. 2). Figure 2. Geographic distribution of the genus Onchidium and its three valid species. The colored dots correspond to the known records for each species. Colored areas correspond to hypothetical ranges proposed based on those known records. Naturally, details about the distribution of each species remain uncertain. For instance, Onchidium typhae may or may not be found on the western coasts of Thailand by the Andaman Sea.