Myrmarachne hashimotoi Yamasaki & Hashimoto & Endo & Hyodo & Itioka & Meleng 2018, sp. nov.

Myrmarachne hashimotoi Yamasaki sp. nov.

(Figs 16–22)

Type material. Holotype: male (FRCS; LMy 20121209 _Kata4), Lambir Hills National Park, Sarawak, Borneo, 9.XII.2012, M. Katayama leg.

Etymology. The specific name is given in honor of Dr. Yoshiaki Hashimoto (Museum of Nature and Human Activities, Hyogo /University of Hyogo).

Diagnosis. Body small to medium, approximately 3.0 mm in length; thoracic part swollen dorsally and laterally. Male distinguishable from other species by dentition of cheliceral teeth and irregularly sinuous fang. Myrmarachne hashimotoi sp. nov. is similar to M. nitidissima (Thorell, 1877), but distinguishable by constricted abdomen and short palpal tibia.

Description. Male (Figs 16–19). Lateral surface of carapace strongly incised by groove behind PLE; thoracic part swollen dorsally and laterally. Chelicera with eight prolateral and three retrolateral teeth on fang furrow. Fang weakly curved, without tooth-like apophysis. Pedicel relatively long but shorter than ALE–PLE. Abdomen pearshaped, strongly constricted at anterior 1/3; with a scutum covering most of dorsum of abdomen.

Male palp (Figs 20–22). Cymbium oval, without distinct apical macrosetae. Embolus coils slightly wider than venter of cymbium. Tegulum oval; spermophore strongly curved at anterior part of tegulum. RTA strongly curved, apically hooked; flange of RTA developed.

Leg macrosetae. Femur I md 1, pd 1; tibia I pv 3, rv 3; metatarsus I pv 2, rv 2; femur IV (right) pd 1. Legs other than left leg I and right leg IV lost.

Coloration and setation (Figs 16–18). Carapace brown, sparsely covered with setae; cephalic dorsum dark brown to black; lateral surface bearing patch of white setae above coxa III. Chelicera light brown. Fang brown. Endite brown. Labium brownish yellow. Sternum brown, slightly tinged with black. Abdomen sparsely covered with long setae; anterior part brownish yellow, tinged with gray, posterior dorsum dark brown; venter gray.

Measurements (1 male). Total length 3.0. Carapace length 1.37, width 0.81. Length of cheliceral paturon of male 1.08. Width of eye row I 0.71; II 0.69; III 0.79. ALE–PLE 0.52; ALE–PME 0.25. Eye size: AME 0.24; ALE 0.11; PME 0.04; PLE 0.13. Pedicel length 0.36. Abdomen length 1.48.

Female. Unknown.

Distribution. Known only from Borneo.

Remarks. Myrmarachne hashimotoi sp. nov. occurs sympatrically with M. endoi Yamasaki & Ahmad, 2013.