Twenty-eight new species of the spider genus Merizocera Fage, 1912 (Araneae, Psilodercidae) from South and Southeast Asia Author Chang, Wan-Jin Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China & Southeast Asia Biological Diversity Research Institute, Chinese Academy of Sciences, Yezin, Nay Pyi Taw 05282, Myanmar & University of Chinese Academy of Sciences, Beijing 100049, China Author Yao, Zhiyuan Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China https://orcid.org/0000-0002-1631-0949 Author Li, Shuqiang Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China & University of Chinese Academy of Sciences, Beijing 100049, China https://orcid.org/0000-0002-3290-5416 lisq@ioz.ac.cn text ZooKeys 2020 961 41 118 http://dx.doi.org/10.3897/zookeys.961.53058 journal article http://dx.doi.org/10.3897/zookeys.961.53058 1313-2970-961-41 B5627BFE56A242B3B3A596BAE07724F4 C1D92F70C65F53668E36B8CF62DB4D8A Merizocera ranong Li sp. nov. Figures 31 , 32 , 54 Type material. Holotype : male (IZCAS), forest of Suk Sum Ran Village ( 9°28.80'N , 98°30.56'E , elevation 46 m), Kapoe District, Ranong , Thailand , 28 October 2014, P. Wongprom leg. Paratype : 1 female (IZCAS), same data as holotype. Etymology. The specific name refers to the type locality; noun in apposition. Diagnosis. Diagnosis features of males and females are discussed in M. betong sp. nov. Males with a crinkly embolus, lamina-like embolus tip, and swollen pyriform bulb (Fig. 31B ). Females with a pair of posteriorly directed tubular spermathecae (Fig. 32A ). Figure 31. Merizocera ranong sp. nov., holotype male. A Bulb, dorsal view B bulb, dorsal view C palp, prolateral view D palp, retrolateral view. Abbreviations: CP = cymbial protrusion, EM = embolus. Description. Male (holotype). Total length 1.28; carapace 0.59 long, 0.52 wide; abdomen 0.64 long, 0.49 wide. Carapace circular, brownish, with dark brown marks laterally and dark brown median stripe on anterior half (Fig. 32C ). Fovea shallow. Thoracic region distinctly elevated medially. Clypeus brownish, with dark brown marks medially. Labium dark brown. Sternum dark brown but lighter medially. Abdomen ovoid, brownish, with darker brown marks dorsally and ventrally. Legs light brown; measurements: I 6.19 (1.70, 0.21, 1.90, 1.62, 0.76), II 4.46 (1.20, 0.20, 1.33, 1.13, 0.61), III 3.40 (0.92, 0.19, 1.00, 0.84, 0.45), IV 5.05 (1.34, 0.20, 1.55, 1.27, 0.69). Palp (Fig. 31A-D ): femur slender, thrice longer than patella; patella not swollen; tibia not swollen; cymbium with distal protrusion, length ratio of dorsal elongation and cymbium 0.90; bulb pale yellow, swollen pyriform with embolus arising distally; embolus with crinkly stalk and lamina-like at the tip, stalk 1/3 length of bulb; conductor absent. Female (paratype). Similar to male in colouration and general features but slightly larger (Fig. 32D, E ). Measurements: total length 1.28; carapace 0.62 long, 0.54 wide; abdomen 0.66 long, 0.51 wide. Leg measurements: I 5.19 (1.36, 0.21, 1.56, 1.33, 0.73), II 4.02 (1.06, 0.20, 1.15, 1.01, 0.60), III 3.25 (0.85, 0.19, 0.89, 0.83, 0.49), IV 4.75 (1.19, 0.20, 1.45, 1.20, 0.71). Epigastric area (Fig. 32B ): dark brown elliptical patch, medially with horizontal pale brown slit. Endogyne (Fig. 32A ) with a pair of posteriorly directed tubular spermathecae, gradually enlarged posteriorly. Figure 32. Merizocera ranong sp. nov., holotype male and paratype female. A Endogyne, dorsal view B female epigastric area, ventral view C male habitus, dorsal view D female habitus, dorsal view E female habitus, ventral view. Abbreviation: SP = spermatheca. Distribution. Known only from the type locality (Thailand; Fig. 54 ).