lO(-) [May, 1S97. 



readily in most pai-ts to blackish-grey when shifted about. The legs are of the same 

 light or dark colour throughout, the hue depending upon the age of the specimen ; 

 the gloss on the tarsus at the best is dull. 



Beneatli, at the base of the wing in both sexes, scales are limited in their dis- 

 tribution almost absolutely to parts interior to the fold of deflection, the exceptions 

 being a few very narrow linear scales at the very commencement of the posterior 

 margin, and some on the nerve-roots bordering the anterior basal cell. Season, 

 September ; an earlier brood has not yet been observed. 



This species, as stated previously, might easily be mistaken for a 

 small form of P. soleata (21) ; but the difference in the texture of 

 the pair of dark spots— smooth-haired in No. 30, ruffled-up in No. 21 

 — facilitates their distinction. 



Sectiox Y of Pericoma ; British species, Nos. 31 and 32. 



Kefer ante, 2ud ser., vol. iv, 32, step 5, and vol. v, pi. iv, P. 31 

 (details). 



Affinities, according to the place of confluence of the radius and 

 cubitus, and to the distribution of bristling hair on the wing, nearest 

 witii Pericoma, IV, B t, f^s previously stated in the Affinities paragraph 

 under that head. In the matter of the prothoracic air-nipples, per- 

 sistent in the male fly, and in the character of the indumentum 

 beneath the wings in this sex, the present Section has something in 

 common with Pericoma, III, B. The shortness and equality in length 

 of the basal cells are marked features, in which it is approached by 

 Psychocla, I. The form of wing no doubt had most to do with the 

 position assigned to these species by Haliday and Van der Wulp or 

 Schiner, who rank them between Pericoma, I, and JJlomyia. 



In the Synopsis, loc. cit., the number of joints in the antenna^ is 

 mis-stated ; and before the synonymy of the species mention ought to 

 have been made of the persistent prothoracic air-nipples of the male 

 fly, which are claviform and clad with appressed scales. Antennae in 

 J 10-jointed ; the scape squamate w^ith elongate scales (black in 

 these species), and the flagellum furnished with whitish-grey or very 

 light sepia-grey or fawn coloured hair, the colour changing with the 

 pose; 1st joint obovoid-oblong, not quite one and half the length of 

 the 2nd, which is snbglobular ; 3rd joint hardly shorter than the 1st, 

 and very little longer than the ith, ovate, tapering to a short, stout 

 beak ; after the Srd joint the remainder diminish very gradually in 

 stoutness without much difference in length, and by a gradual length- 

 ening of the beak become fusiform-ovate ; the beaks nowhere exceed 

 three-eighths of a joint in length, and after the 12th joint gradually 

 shorten ; hair arranged in pluri-seriate verticils, that leave the tapering 



