Damarchus bifidus Gravely, 1935

Kunsete, Chawakorn, Sivayyapram, Varat, Traiyasut, Prapun, Thanoosing, Chawatat, Khamwan, Kitiwat & Warrit, Natapot, 2020, Records and redescription of a mygalomorph spider genus ignored for over 100 years with a new species: the genus Atmetochilus Simon, 1887 (Araneae Nemesiidae) in Thailand, Zootaxa 4819 (3), pp. 521-543 : 523

Damarchus bifidus Gravely, 1935 , comb. nov

Damarchus bifidus Gravely, 1935: 70 , fig. 1a.

Atmetochilus bifidus: Zonstein & Marusik, 2014: 278 , fig. 25.

Diagnosis: Males are similar to those of D. assamensis and D. excavatus in size and male genitalic structure, but differ in the shape of the base of metatarsus I, which is lightly excavate with an extensive area of fine spiniform denticles. The tibial apophysis of D. bifidus differs from those of other species in consisting of three distinct parts, including a basal part which arises minutely from the margin of tibia I, and two distal parts (see Gravely 1935: 70, fig. 1a). The female is similar to those of D. assamensis and D. excavatus in overall size and shape.

Comments. This species was originally placed in Damarchus but it was transferred to Atmetochilus by Zonstein and Marusik (2014) by using male tibial spur character. However, we received a photo of A. bifidus sternum from Mrs Shelley Acharya, the curator at ZSI. We observed that the species has no confluent sternal sigilla ( Fig. 1F ). A discussion with Dr Robert Raven (pers. comm.) resulted in a decision to transfer “ A. bifidus ” back to Damarchus .

Figures

FIGURE 1A–F. Atmetochilus and Damarchus bifidus. Sternum.A. Atmetochilus songsangchotei sp. nov. male holotype (ARA- 2017-116); B. A. songsangchotei sp. nov. female paratype (ARA-2017-117); C. A. fossor female neotype (ARA-2018-132); D. A. atriceps female (ARA-2018-173); E. A. atriceps female lectotype; F. Damarchus bifidus type specimen.