Delimitation of the spider genus Sesieutes Simon, 1897, with descriptions of five new species from South East Asia (Araneae: Corinnidae) Author Dankittipakul Author Deeleman-Reinhold text Journal of Natural History 2013 47 3 167 195 http://www.tandfonline.com/doi/abs/10.1080/00222933.2012.742165 journal article 10.1080/00222933.2012.742165 01962892-5ab4-4828-a43c-838f01b109b6 583948 97EFA23C-7537-4156-8EF0-2D38CF889F5B Sesieutes bifidus sp. nov. ( Figures 1 G,H, 7 A–E, 10 G) Type material Holotype . ♂ , Malaysia , Pahang State , Cameron Highland , Tanah Rata , Mt Jasar , 1700 m , sifting leaf litter, 18 April to 11 May 2009 , leg. P. Banar ( MHNG , WM–1 ) . Paratypes . One ♀ , Cameron Highland , Tanah Rata , 470–1550 m , sifting leaf litter and rotten wood, 25 April to 15 May 2009 , leg. P. Banar ( MHNG , 2 ) . Diagnosis Male of S. bifidus sp. nov. can be easily recognized by the bifid distal RTA of the male palp ( Figure 7C ). Females closely resemble those of S. abruptus sp. nov. , but can be distinguished by the more elongated insemination ducts provided with one additional coil (compare Figures 7 E and 6 E). Figure 7. Sesieutes bifidus sp. nov. Holotype, male palp (A–C), ventral view (A), prolateral view (B), retrolateral view (C). Paratype, female (D, E), epigyne, ventral view (D); internal genitalia, dorsal view (E). Scale bars 0.1 mm (A–C); 0.2 5 mm (D, E). Etymology The specific epithet is a Latinized adjective referring to a bifid distal RTA of the male palp. Description Male ( holotype ). Total length 6.40; prosoma 3.20 long, 2.26 wide; opisthosoma 3.60 long, 2.20 wide. Leg measurements: leg I 8.80 (2.40, 3.20, 1.84, 1.36); II 7.52 (2.00, 2.72, 1.60, 1.20); III 6.36 (1.84, 1.80, 1.60, 1.12); IV 9.76 (2.56, 3.04, 2.72, 1.44). Leg spination. Leg I: Fe p–1, Ti v–2–2 –2–2–2–2, Mt v–2–2 –2; leg II: Ti v–2–2 –2–2–2, Mt v–2–2 –2; leg III: Ti p–1 v–2–2 –1 r–1, Mt p–1 v–2–2 –1 r–1; leg IV: Fe d–0–1, Ti v–2–2 –2 r–1, Mt p–1, v–1–1 –1–1, r–1. Pattern and coloration ( Figure 1G ). Carapace reddish brown, with dark marking forming striae; integument smooth; fovea indistinct, replaced by shallow, longitudinal depression; chelicerae, labium and gnathocoxae yellowish brown; sternum brown, margin and extensions dark brown; legs orange, anterior femora and tibiae slightly darker than other segments. Opisthosoma ovoid; dorsum grey; venter pale; dorsal scutum ovoid, heavily sclerotized, occupying three-quarters of length of opisthosoma. Palp ( Figure 7A–C ). Palpal tibia with digitiform prolateral excrescence; proximal RTA truncated, with membranous anterior surface, triangular with subspherical base in prolateral view, rectangular in retrolateral view; distal RTA heavily sclerotized, cylindrical, apex bifid, with sharply pointed basal tooth and blunt apical tooth; tegulum more or less spherical in ventral view, deeply excavated apico-prolaterally; conductor lanceolated, gradually tapering anteriorly, originating on anterior portion of tegulum; tegular apophysis spiniform, hyaline, originating near base of conductor; embolic base originating on apical portion of tegulum. Female ( paratype , MHNG ). Total length 6.30; prosoma 3.00 long, 2.10 wide; opisthosoma 3.30 long, 1.68 wide. Leg measurements: leg I 8.25 (2.25, 3.00, 1.72, 1.26); II 7.04 (1.86, 2.54, 1.50, 1.12); III 5.98 (1.72, 1.68, 1.50, 1.06); IV 9.14 (2.40, 2.84, 2.54, 1.36). Leg spination. Leg I: Fe d–1 p–1, Ti v–2–2 –2–2 + pv–1, Mt v–2–2 –2; leg II: Ti v–2–2 –2–2, Mt v–2–2 –2; leg III: Ti p–1 v–2–2 –1 r–1, Mt p–1– 1 v –1 r–1; leg IV: Ti d–1 p–1 v–2–2 r–1–1, Mt p–1 v–1–2 r–1. Pattern and coloration ( Figure 1H ). Carapace yellowish brown, with dark striae; integument smooth; fovea indistinct, represented by shallow depression; chelicerae, labium and gnathocoxae brown; sternum yellow, with dark brown margin; legs yellow, except anterior femora slightly darker than other leg segments. Opisthosoma elongateovoid; dorsum pale grey; venter pale; dorsal scutum orange-brown, semi-circular, occupying one-fifth length of opisthosoma; spinnerets white. Genitalia ( Figures 7 D,E, 10 G). Epigastric scutum weakly sclerotized, with narrowed, spatulate-shaped copulatory orifices situated anteriorly; proximal ducts funnelshaped, very broad, lateral margin straight; insemination ducts short, forming one or two coils; spermathecae reniform, gland pores situated more or less posteriorly. Natural history Sesieutes bifidus sp. nov. inhabits a remnant patch of evergreen hill forests on Cameron Highland mountainous resort where most of the area is cultivated land. Distribution Known only from the type locality in Malaysia.