PLATYCHIRUS, 55 



central bump bare, as is front raouth-edge and space before cheeks; 

 pubescence o£ face black. Antennae brownish-black, 3rd joint 

 reddish below (at least in life). Occipital inart^in with greyish- 

 white pubescence, except behind vertex where it is black. In $ , 

 upper part of irons shining blue-black ; pubescence of face whitish 

 and sparser than in c? . Thorax aeneous-black ( d" ), or shining 

 blue-black ( $ ), with light brown (6)1 or very short pale ( ? ), 

 pubescence. Abdomen in cf dull black, with pairs of incon- 

 spicuous spots ; those on 2ad segment shining yellowish-peiieous, 

 nearly filling side margins, well separated ; on 3rcl segment 

 the spots brownish-yellow, subtriangular, close to basal corners, 

 extending over sides; on 4th segment a similar but more quadrate 

 pair of spots ; pubescence of abdomen pale basally, short and 

 black on black parts of 3rd, 4th and 5th segments ; genitalia 

 shining aeneous with son)e black hairs. In 5 with three pairs of 

 shining bluish subquadrate spots, hence practically the abdomen 

 has dull black entire bands connected by a broad, dorsal line, the 

 5tli segment almost all shining; sometimes the spots have a slight 

 yellowish tinge. Ler/s in J mainly black ; extreme base of fore 

 femora, fore tibiae except about the middle, fore tarsi except the 

 light brown last joint, middle tibiae broadly at base narrowly at 

 tip, middle tarsi at base and hind knees narrowly, yellow. Fore 

 femora on hinder side with a long split white hair at extreme base; 

 long, tangled black hairs follow, and then three black hairs, longer 

 still, isolated one from another ; middle femora on front side with a 

 row of about eight stiff, short black hairs, and a single long re- 

 current black hair near tip; hind femora with fairly abundant 

 pale pubescence. Fore tibiae dilated on apical third, with from 

 one to three long black hairs behind near middle ; middle pair 

 with two or three such hairs and some others longer tlian the 

 ordinary pubescence ; hind tibiae with some black and yellow 

 rather long hairs in front below middle. Front tarsi gradually 

 diminishing in width from base, 1st joint about as wide as tip of 

 tibiae ; hind metatarsi barely dilated. In $ , anterior femora and 

 basal half of tibiae mainly dull orange ; rest of anterior legs 

 generally darkened; tip of middle tibiae orange; hind knees 

 rather broadly orange ; the legs often paler, especially the middle 

 pair. IFtH^i'with a faint blackish tinge in cJiPJ^ler in 2 ; stigma 

 pale brown ; halteres blackish-brown ( c? ) or orange ( $ )• 



Len'jth, 8-8.7 mm. 



The above description abbreviated from Verrall *. 



Simla, 9. V. 1910; Theog, 27. iv. 1907; Matiana {Annnndale) ; 

 Darjiling, 2.x. 1908 {Bnmetti). The species occurs over all 

 Europe, in Siberia, Farue Islands, Iceland, and North America. 



The S closely resembles Melanostoma arnhiguum, but is known 

 by the dilated front tibia?. 



* 'British Files,' Syrphidoe, p. 280. 



