Cymatopus malayensis Parent, 1935 Figs. 1, 2 Parent, 1935a: 208 (figs 26–31). Material examined. THAILAND: Gulf of Thailand (South China Sea): 16 males, 16 females, Laem Kho Kwang, Chumphon Province, 17 February 2015, sweep netting, 10°30′48.7″N, 99°15′52.0″E; 13 males, 13 females, Ban Thong Tom Yai, Sawee, Chumphon Province, 19 February 2015, sweep netting, 10°12′39.2″N, 99°12′21.4″E. (PSUNHM). Andaman Sea (Indian Ocean): 8 males, 4 males, Tarutao Island, Langu, Satun Province, 9 January 2015, sweep netting, 6°44′19.2″N 99°38′45.4″E, coll. Abdulloh Samoh; 1 male; 4 females, Nang thong beach, 8°38′40.46′N, 98°14′47.71″E, Phang-Nga Province, 4 November 2017, hand collecting on concrete wall on the beach, leg. P. Grootaert & I. Van de Velde. (RBINS). NGS barcodes see annex 1. Diagnosis. A large species with modified fore leg. Fore tibia anteriorly with a black foliaceous bristle and metatarsus (tarsomere 1) elongated with a distorted tip bearing strong twisted bristles. Fore tarsomeres 4 and 5 flattened and brown. Wing with hind margin deeply indented (Fig. 1) and fields of enlarged microtrichia on wing membrane. Bionomics. The adult flies are found in the splash zone of rocky shores. Distribution. Shores of the Andaman Sea and the Gulf of Thailand (Grootaert & Meuffels, 2001). Thailand, Malaysia, Singapore and Borneo.

Published as part of Samoh, Abdulloh, Satasook, Chutamas & Grootaert, Patrick, 2018, New data on the marine genera Cymatopus Kertèsz and Thambemyia Oldroyd (Insecta, Diptera, Dolichopodidae) from rocky shores in southern Thailand with the description of a new species, pp. 258-267 in Raffles Bulletin of Zoology 66 on page 259, DOI: 10.5281/zenodo.4503124