On the taxonomic status and biogeography of the Isolapotamidae Bott, 1970 (Decapoda, Brachyura) Author Brandis, Dirk text Journal of Natural History 2002 2002-07-31 36 11 1291 1339 http://www.tandfonline.com/doi/abs/10.1080/00222930110051743 journal article 10.1080/00222930110051743 1464-5262 5298522 Dromotelphus a chaseni (Roux, 1934) (gure 19a–c) Potamon (Potamiscus) chaseni Roux, 1934 : gure 1, pl. 4, gures 1, 2; Roux, 1936: 37, gures 7, 8. Isolapotamon chaseni : Bott, 1970b: 190 , pl. 41, gure 76, pl. 55, gure 77. Stoliczia chaseni : Ng, 1988a: 64 , pl. 2A, gure 28. LECTOTYPE . 1 ( NMB 882 a) Cameron Highlands , Malay peninsular, don. Mus. Singapore 1934. Material . Malaysia : 2, 1: SMF 2836, Malayan peninsular, Cameron Highlands : 4ss29¾ 00 ² N 101ss23¾ 00 ² E . Diagnosis. Carapace smooth, deeply grooved, lateral regions granulated, anterolateral margin well developed, serrated with equal teeth, postorbital margin and postorbital lobe fused to sharp margin, which leads nearly to the lateral edge; chelipeds unequal, both slightly gaping, palms rugose, pleon stoutly triangular. Terminal joint of rst gonopod long, slender cylindrical, slightly curved outwards, overlapping zone reaching only ventral part, in middle with small mesial bulging at the overlapping margin. Type locality . Malayan peninsula, Cameron Highlands. Distribution. Malayan peninsula, Cameron Highlands. Measurements. 24.8: 32: 13.8: 9.7 ( holotype NMB 882a). Remarks. D. chaseni from the Cameron highlands of Malaysia was originally assigned by Roux (1934) to Potamon ( Potamiscus ) Alcock, 1909 . Bott (1970b) Taxonomy and biogeography of the family Isolapotamidae 1327 transferred it to Isolapotamon but the reason for this remains unclear. Bott (1968) established Isolapotamon for a group of species, with a rst gonopod with a terminal joint longer, or as long as the subterminal joint. Dromotelphusa chaseni distinctly has a rst gonopod with the terminal joint much shorter than the subterminal joint, and Ng (1988a) transferred it to Stoliczia , Bott, 1966 , based on carapace characters, and its highland type locality. Re-examination of the holotype of D. chaseni clearly showed that the second gonopod has the characteristic features of Isolapotamidae and that the rst gonopod agreed with that of D. longipes . On the other hand, the type species of Stoliczka stoliczkana shows the typical potamid-like second gonopod with a large tube lumen and two attached and incurved lateral margins as shown in gure 2a.