Sexual Dimorphism in the Rutelid genus Parasiasia. 495 



P. 5w?*??im^m, Ohaus, is a species of this group differing 

 sexually in a very remarkable way. The male of this has 

 been described under the name oiP.Nonfriedi by Dr.Ohaus 

 who informs me that he possesses four specimens of the first 

 form and five of the second, of which the former are all 

 females and the latter all males, and he has himself 

 suggested in correspondence Avith me that they may 

 belong to a single species. Confirmatory evidence is 

 supplied by others which I have examined, and which are 

 of the same sexes respectively, with the exception of a 

 single male in M. Oberthlir's collection which has the 

 female coloration. Another male in the same collection 

 shows an approximation to that form. As the two forms 

 have been collected together in the same place there can 

 be no doubt as to their being normally sexual. Both 

 exhibit the same velvety surface upon the elytra shown 

 by the whole surface of P. Westwoodi, but whereas in the 

 male the ground-colour of the elytra is a reddish-chocolate 

 marked only with two small black spots near the suture, 

 in the female the black has spread over the whole surface 

 leaving only two transverse crescent-shaped marks of the 

 lighter shade. In the male the thorax and scutellum 

 are testaceous and the head only black, and in the female 

 all are black except the thorax at the sides. 



The British Museum contains male and female speci- 

 mens of another new species isolated as regards its claw 

 structure, and apparently representing an intermediate 

 stage in the process by which the peculiar condition 

 characterising the male in the last group has been arrived 

 at. The two sexes are alike except in this respect. The 

 claws of the second and third pairs of legs are divided in 

 both sexes but in the male one claw on each tarsus is 

 thickened, the ungual lobe of the middle feet showing an 

 approximation to its form in the Westwoodi group, while 

 the expanded inner anterior claw is like that so common 

 in the males of the Anomalinx, to which the present 

 genus shows otherwise few structural resemblances. 

 There is a second male of this species in M. Oberthlir's 

 collection. 



Parastasia anomala, sp. n. 



Elongata, paulo depressa, rufa, capite, scutello, tarsisque (corpore 

 subtus, femoribus tibiisque plus minusve) nigris ; capite grosse, 

 prothorace crebre, pvmctatis, hoc parum convexo antice valde 



