PAEASITIC ON ANTS. 431 



as in the typical Uropodas. The genital opening of 

 the male is rather large, round, and placed centrally 

 between the coxee of the second pair of legs. The 

 female appears only to be distinguished from the male 

 by being more strongly chitinised, and by the con- 

 spicuous valval plate which occupies the whole space 

 between the coxse of the second and third pairs of legs 

 and extends beyond both. 



The nymph is less square in the abdomen than the 

 adult, and the border of hairs is absent ; the margin is 

 somewhat undulated, the concave undulations being so 

 placed as to give free action to the legs when raised ; 

 the central depression of the abdomen is far less 

 marked than in the adult; a slight ridge runs all 

 round the dorsal surface a little within the margin ; 

 four ridges, two anterior and two posterior, run from 

 the circumscribing ridge to a raised ellipse in the centre ; 

 there are not any plates for the protection of the legs, 

 and the coxae of the first pair are not flattened as in the 

 adult. 



This mite lives in the nests of Formica fiava. 



Description of a New Genus and Species of Phoriaoe 

 parasitic on Ants. By G. H.VERRALL,Esq., Memb. 

 En torn. Soc. 



Sir John Lubbock has kindly forwarded for my exa- 

 mination and determination certain specimens of dip- 

 terous insects said to have been found parasitic on species 

 of ants, which latter he has been studying with care as 

 to their habits. Having given considerable attention to 

 the family Phoridse, I was agreeably surprised to find 

 the parasitic specimens to be forms new to science. 

 One of these is a new species of the genus Phora ; the 

 other I regard as possessing characters sui generis, and 

 hence define it imder the generic title Platyphora, at 



