Plistobunus rapax Pocock, 1903

Lian, Wei-Guang, Zhang, Chao & Zhang, Feng, 2011, Review of the genus Plistobunus Pocock, 1903, with description of a new species from Hainan Island, China (Opiliones, Laniatores, Epedanidae), ZooKeys 112, pp. 39-52 : 41-43

Plistobunus rapax Pocock, 1903 Figs 1-6

Plistobunus rapax Pocock 1903: 447, fig. 2; Roewer 1912: 232; 1923: 207, fig. 236; 1938: 124, fig. 43.

Type material examined.

Holotype ♂, in 75% Industrial Methylated Spirit (IMS), labelled as follows: "56. 113, Plistobunus rapax Pocock, Hong Kong" (BMNH 56. 113).

Redescription.

Male holotype (habitus see Fig. 1): Coloration. Body yellowish brown and appendages yellow. Lateral margins and free tergites banded with dark brown. Chelicerae dorsally reticulated with dark brown.

Dorsum.

Dorsal scutum nearly trapezoid in shape; widest portion at fourth scutal area; anterior margin of carapace armed with a transverse row of four to five setiferous tubercles. Ocularium long oval, armed with a short median spine. Opisthosomal region of scutum with four areas, first area completely smooth, without a median furrow or line; second area has four hair-tipped tubercles, of which two median ones are longer than others; third area covered with two relatively tubercles; fourth area with a transverse row of seven tubercles, of which the median one is longest. Free tergites with hair-tipped granules arraged in a transverse; each lateral margin of the scutum with a longitudinal row of granules.

Venter.

Coxae I–III armed with a row of hair-tipped tubercles, additionally coxa I covered with a row of relatively small hair-tipped tubercles. Coxa III with a row of low humps along front and hind margins. Coxa IV with a row of small hair-tipped granules. Some small hair-tipped granules scttered over surfaces of coxae I–IV. Tracheal stigma clearly visible.

Chelicera (Figs 2-4).

Proximal segment fairly strong, distinctly armed with two prominent spines dorsally, numerous hair-tipped tubercles scattered over ventral and lateral surface. Second segment distinctly expanded, armed with a row of four strong hair-tipped bifid tubercles on the prodorsal surface. A few hair-tipped granules scattered over the prodorsal surface. Fingers relatively strong, cutting edges dentate (Fig. 4).

Pedipalpus (Figs 5-6).

Relatively long and slender. Trochanter with a single setiferous tubercle dorsally, three ventrally. Femur dorsally with a longitudinal row of seven setiferous tubercles; ventrally with a longitudinal row of nine setiferous tubercles; distally with two setiferous tubercles medially. Patella ectally with three setiferous tubercles, disto-medially with two ones. Tibia with three medial and five ectal setiferous tubercles. Tarsus with four setiferous tubercles on both sides of ventral surface. Tibia with a longitudinal row of three granules ventrally. Tarsal claw long, strongly curved.

Legs.

All of legs were destroyed and missing but their trochanters ventrally with two hair-tipped tubercles, their femora armed with a row of setiferous tubercles.

Penis.

Lost.

Measurements.

Body 3.03 long, scutum 2.64 long, 2.25 with at the widest portion; ocularium 0.65 long, 0.35 wide.

Distribution.

China: Hong Kong.

Remarks.

Plistobunus rapax is only known from the type specimen. To make matters worse, the type specimen is in an incomplete state. All legs were missing and the penis is lost. Roewer at first ( 1912, 1923) did not examine the holotype by himself, and learned from Hirst that all the tarsi of legs in type specimen were missing. According to the description of Pocock, he assumed that the species should be placed in the subfamily Epedaninae , family Phalangodidae . Later Roewer (1937) examined the type specimen, he found that all legs were lost, then he ( 1938) listed it also in the family Epedanidae , merely based on the original description and Hirst’s information. We can not confirm when the penis was lost, as Roewer did not usually describe and illustrate the structure of penis, because he was unaware of the importance of genital diagnostic characters.