April, 189(5. > ^'^ 



Scbiner has explained (loc. cif.) the reasons that guided his choice 

 of the species to which the name canescens has been appropriated. 

 This is not the species thus named by Haliday in Walker's Ins. Brit. 

 Dipt., vol. iii, p. 254, line 29, = P. {auriculata, CvLvt.) fuscn, Macquart ; 

 nor id., op. cit., p. 258, No. 5, = P. notabilis, Etn. Neither is it the 

 P. canescens of Verrall's List of Brit. Dipt., p. 10 (1888),= P. deci- 

 piens, ^tn. ,—Ji.de Verrall's cabinet. 



10. Peuicoma exquisita, Etn. 



P. exquisita, ante, 2nd ser., vol. iv, 122, and vol. v, pi. ii, P. 10 



(details). 



The (J antennae in this species differ from those of P. canescens, chiefly in the 

 absence of hairs on the first two joints, and in the 3rd joint being ovoid and shorter 

 by one-fourth than the 2nd joint. Articular appendages of the flageUum short 

 Pubescence of the notum reddish-brown. 



Witliin the region of bristling hair, the dark fascia across the bases of the nerve- 

 forks is much broader in its anterior half than behind, and at the anal nervure it is 

 parted in two, opposite the flaxen hair-spot (partly composed of bristling hair) at 

 the end of the axillar nervnre ; its interior border from the radius to the inner 

 margin is deeply (almost semicircularly) concave, and passes by two conspicuous 

 opposite black spots placed one at the anterior fork, the other close to the posterior 

 fork on the posterior pobrachial branch and the postical nervure ; its outer border, 

 sharply zigzag, is connected with the dark apical region at the prsebrachial nervure. 

 The flaxen bristling hairs at the outer limits of the rufiled hair are skirted externally 

 by other hairs of the same colour ascending outwards in two divergent ranks from 

 each nervure. 



The colour of the thoracic pubescence, the more strongly marked 

 flaxen spots at the ends of most of the nervures, and (on close in- 

 spection) the black spots by the forks, serve to distinguish this species 

 in the net from the following. In latitude its geographical range is 

 considerable ; Mr. King met with it at Loch Maree (4 ^ , 6 ? ), and 

 a single male has been taken in Algeria, this year (1895). 



11. Pericoma fallax, Etn. 



Pericoma fallax, ante, 2nd ser, vol. iv, 122, and vol. v, pi. ii, 

 P. 11 (details). 



Within the region of bristling hair, the dark fascia across the bases of the 

 forks, broad and subtransverse in its anterior half, tapei's posteriorly much less than 

 in P. exquisita, and is deflected outwards at the anal nervure without isolating any 

 of the flaxen hairs at the end of the asillar ; its interior border, from the radius to 

 the anal nervure is almost transverse, opposite the median angle of its zigzag or 

 W-like outer border, which is confluent along the pra^bi'achial nervure, in the usual 

 manner, with the dark apical region ; the dark hairs about the forks do not consti- 

 tute conspicuous spots, but match in tint the remainder of the fascia. 



