Beetles of the family Uutelid^. ^61 



The closely related insect described by Bates under the 

 name of A. nutans must be regarded as a partially dimor- 

 phic species, the entirely black variety consisting of both 

 sexes apparently in about equal numbers, while the speci- 

 mens with red elytra are females and those in which they 

 are more or less bordered with black are males. This 

 species is very much more variable than the preceding 

 one, the varieties being much less constant, and as it is 

 in other respects less specialised than A. vidua it may 

 possibly be regarded as representing the ancestral form 

 of the latter in which the separation of the sexes has not 

 been entirely completed. 



Another example is A. oblivia, Horn, a North American 

 species, which, as is shown by his description of the claws. 

 Dr. Horn has described from the male sex only. Speci- 

 mens of the female in the British Museum are entirely 

 testaceous in colour, the metallic lustre only being rather 

 more apparent on the thorax, which is also - somewhat 

 more elongate. The outer anterior claw, as is usual in 

 this sex, is approximately equally cleft, and the lower 

 tibial tooth long and curved. 



The fourth New World example is the common North 

 American A. lucicola, Fabr., in which the female is either 

 wholly testaceous, or testaceous with a very narrow black 

 external margin to the elytra, and the male either entirely 

 black or testaceous with the thorax wholly or partially 

 black and a black suture and margin to the elytra. 



Of the next species the two forms have been described 

 by M. Fairmaire under the names of Pojnllia cxarata and 

 cinnabarina, and although I have only been able to ex- 

 amine three specimens, the characters mentioned by the 

 author leave little doubt that the forms are sexual and not 

 merely varieties. M. Fairmaire's P. cxarata is an insect 

 of a deep bluish or greenish black colour of which I have 

 seen two individuals, both of them males ; and the de- 

 scription given of the front tarsus of which the "fourth" joint 

 (obviously intended for the fifth) is inflated, and the en- 

 larged outer claw, clearly shows that M. Fairmaire's speci- 

 mens are also of that sex. Subsequently an insect similarly 

 coloured but with its elytra of a bright brick-red was 

 described from the same locality (Yunnan, in S.W. China), 

 and this from a specimen before me proves to be the 

 female of exarata. The slightly larger size and relatively 

 shorter elytra (due to a lateral expansion peculiar to the 



