488 Mr. G. J. Arrow on 



exception of two clearly defined yellow patches on the 

 elytra, and the males nearly smooth and of a more or less 

 light mahogany colour into which the pale markings 

 partly melt. Of several apparently allied species the males 

 only have been described. 



Another insect in which the sexes exliibit similar differ- 

 ences is P. discolor, Westw., an insect described from the 

 Philippine Is. of which the type is a male. A series 

 of specimens of the same sex in M. Oberthtir's collection 

 exhibit all gradations from this form, in which, of the 

 upper surface, only the head, scutcllum and a very narrow 

 line bordering the elytra are black, to one in which only 

 the thorax remains red. From the light forms of this I 

 cannot distinguish F. scutcllaris, Erichs., described from 

 Sumatra, A specimen in the British Museum is from 

 Penang and brought with this insect is a female which I 

 believe to be the same. A similar one was taken with 

 M. Oberthtir's Philippine specimens. This female form is 

 strikingly different in appeai^ance, being entirely black, 

 rather larger and more parallel-sided than the male and 

 coarsely striately punctured. The claws differ in the two 

 sexes as described above. This appears to be a somewhat 

 common type of female in the genus, those of several 

 species being extremely similar. 



Of the two following new species related to F. discolor, 

 F. unicolor exhibits a similar sexual disjiarity in color- 

 ation, and the sexes of F. altemata, a very conspicuously 

 coloured insect, differ only in claw-structure. 



Farastasia unicolor, sp. n. (Plate XVII, figs. 11 and 12.) 



Convexa, nitida, capite prothoraceque grosse, lioc postice rarius, 

 pimctatis ; scutello vix punctato ; elytris lineato-punctatis ; 

 (^ fulvo-bnumea, capite, pedibus, corpore siibtus niargiuibusque 

 oiuTiibus prothoracis, sciitelli et elytri)rum tenuissime fuscis, undique 

 subtiliter punctata, pygidii medio la3vi ; tarsoriim mediorum et 

 posticorum unguibus divisis. Long. 16 ni.ni. 



5 tota nigra, plus elongata, fortius punctata, pygidio subtiliter 

 striolato ; unguibus omnibus simjjlicibus. Long. 18 m.m. 



Hab. N. Borneo : Sandakan ; Elopura. 



This insect is exceedingly closely allied to F. discolor, 

 Westw., and indeed the black females are hardly distin- 

 guishable, but the males are at once separable by their 



