1906.] 269 



POLIETES RIRTICRURA, Meade, ?. 



BY JAMES WATEllSTON, B.D., B SC. 



Writing in 1897, Meade has still to say of this rare species : 

 "only the male is known." Since then the additional examples taken 

 have been few and all of them males. I therefore avail myself of the 

 opportunity of describing a ? recently secured in Arran. 



The usual generic character for PoUetes, End., viz., facial cilia- 

 tion, is less marked in liirticrura (^ than in either of its congeners. 

 Tn the $ this feature is still less obvious, which led us to seek some 

 additional differentia for the ? $ of PoUetes, lind., from those of 

 the closely allied Hyetodesia side. Two points may be referred 

 to, viz. : — 



(a.) The presence in all three spp. of a pair of decussating 

 bristles below the ocellar triangle. This is rare in Hyetodesia. 

 (b.) Between the upper fronto-orbital bristles and the eye margin 

 there are on either side in the $ PoUetes 2-3 stout curved bristles 

 directed downwards. These are absent in the ? Hyetodesia where 

 the line they form is occupied by a row of fine hairs. 



In general the ? is not. so dark looking as the S ■ Grround colour, silvery-grey 

 with a bluish tinge. On this the thoracic markings stand well out, as in P. lardaria. 



Head : — Eyes long haired, the hairs of a tawny colour. Frontal stripe, velvet 

 black. Face and cheeks silvery, darker behind the eyes. Antennae black. Arista 

 swollen basally and long haired for nearly its whole length. 



Thorax: — Four black stripes well defined to beyond the suture. Four dorso- 

 central post sutural bristles. Scutellum black, with a pair of silvery patches near 

 the apex. 



Wings :—'Dwek tinged, as in the $. Bases with calyptra orange. Margin of 

 the latter deep orange, with paler ciliation. Cross veins slightly clouded. Edging 

 of the postrial lighter than in $ . 



Boundaries of subcostal cell, radial, anal and axillary veins yellow. 



Halteres : — 'Knoh blackish-brown j stalk lighter. 



In describing the chaetotaxy of the legs, the system recently 

 advocated in this Magazine by Mr. Grimshaw has been followed 

 (see Ent. Mo. Mag., second series, vol. xvi, p. 173). 



I have here had the benefit of Mr. Grimshaw's revision and 

 suggestion, for which my heartiest thanks are due. Of course the 

 detailed characters must be of very unequal value, but I have not at 

 present investigated which are generic and which specific. 



Fore-leg : — Femur. Row of dorsal bristles, two of which are long, erect, curved 

 at beyond one-half and at two-thirds respectively. Between the latter and the apex, 



