450 JOURNAL, BOMBAY NATURAL HISTORY SOCIETY, Vol. IX. 



The species of the genus Rhax do not appear to differ greatly from 

 each other in any characters except colour, and possibly size and length 

 of limbs, so that the description given above of the dentition of the 

 jaws, spine-armature of the legs, &c, may be taken as applying 

 tolerably accurately to all the species enumerated in this paper. 

 (6) Rhax brevipes (Gervais), (PI. A, Fig. 4, & PI. B, Fig. 3). 



Solpuga brevipes, Gervais, Insectes Apteres, 3, p. 87 (1844). 



The type of this species, bearing the ticket Nepal, Hardwicke- 

 Bequest, and labelled by Gervais, is in the British Museum of Natural 

 History. The head plate is deep black with a yellowish-green patch at 

 its antero-lateral angles ; the abdomen is quite black ; the free thoracic 

 segments lying behind the head are paler but lightly infuscate ; the 

 mandibles are deep reddish-brown, the legs and palpi yellow ; on the 

 palp, however, the tarsus and protarsus, except just its proximal end, are 

 deep brown, and on the legs of the first pair the tarsus and distal end 

 of the protarsus are also deep brown. 



This species is very nearly related to the Algerian species Rhax 

 ochropus of L. Dufour. But, according to Simon, the latter has no 

 small tooth in front of the great fang on the movable digit of the 

 mandible, while in R. brevipes this tooth is very noticeable. Moreover, 

 the published figures of R. ochropus show that the entire protarsus 

 and tarsus of the legs of the first pair are reddish-brown. R. ochropus 

 ia, however, unfortunately unknown to me, so that I am unable fur- 

 ther to compare the two species. 



R. brevipes also seems to be very nearly allied to, if it be not identical 

 with, the Persian species R. phalangium^ Oliv. The latter, however, 

 has been too briefly characterised to be identifiable. 



In addition to the example mentioned above as ticketed Nepal, the 

 British Museum has a second example of apparently the same species 

 from Maballah, and a third which is vaguely ticketed East Indies, 

 (7) Rhax semi/lava, Pocock (PI. B, Fig. 2). 



Ann. Mag. Nat. Hist. (6), iv, p. 473 (1889). 



The single known example of this species is, like the type of 

 R. brevipes, a female with the abdomen not distended. 



The two specie3 are very nearly related, but R. semijiava may be 

 distinguished at a glance by the difference in the colouring of its 

 abdomen. This part of the body instead of being black as in 

 R. brevipes, is yellowish below and at the sides, but on the dorsal surface 

 the anterior 5 tergal plates are blackish, the 5th, however, being yellow 



