541. 

 PORPHYROPS WILSONI. 



Order Diptera. Fam. Dolichopidae. 



Type of the Genus, Dolichopus diaphanus Fab. 

 PoRPHYROPS Meig., Hal., Curt. — Dolichopus Fub. — Musca Fab. 



Antennce inserted towards the ui)per part of the face, porrected,, 

 contiguous, 5-jointed, basal joint obtrigonate, bristly above, 2nd 

 subglobose and clothed with bristles, 3rd the largest, subtrigo- 

 nate-ovate and often elongated in the males, 4th a long slender 

 joint sometimes attached to the apex and at others to the upper 

 edge of the 3rd, generally near to the apex, 5th a very long 

 bristle, drooping or forming a slight angle at the base and clothed 

 with very short hairs, distinct only at the apex in some (3). 

 Trophi short in the male ("2 (J) inserted in a small cavity beneath 

 the head, much larger exserted and forming a thick trigonate 

 beak in the female (2 $). 



Labrum shorter than the lip, very horny, hollow, dilated at the 

 base, the apex pointed and pubescent, with a tooth on each side 

 beneath (1 ^ and $ b). 



Tongue short and very rigid (c), incurved and acute in the $ . 

 Palpi large ovate, comjjosed of one very pubescent joint, fur- 

 nished also with a few long bristles in the male (1 ^ f), thin 

 and pubescent only in the female (1 ^ f)- 



Lip short but thick, formed of 2 large lobes, clothed with hairs 



and long bristles in the male (1 ^ g), much larger, horny and 



cleft only in the female (1 % g). 



Head hemispherical : eyes very pubescent, large, lateral, nearly meeting 



in front in the male (2 ^) : with a considerably broader space between 



them in the female (2 *) .- ocelli 3 in triangle, placed on a tubercle 



at the hinder part of the crown of the head. Thorax oblong : scu- 



tellum lunate. Abdomen more or less attenuated, 6-jointed, with 



2 lobes and 2 filaments beneath the apex in the males (7) ; sometimes 



pointed in the female. Wings incumbent and parallel, broad, 4th 



longitudinal nervure bent towards the apex, tvith a transverse nervure 



uniting it and the 5th : halteres small and capitate. Legs, generally 



slender, hinder pair long : thighs and tibipe simple : tarsi 5-jointed, 



basal joint the longest, except in the posterior, in which the 2 first 



are nearly of equal length. 



Obs. All the dissections are from P. Wilsoni excepting Nos. 1 ^ and 3. 



WiLSONi Curt. MSS.— Guide, Gen. 1255. 12\ 



Coppery-green, hypostoma white, very narrow and silvery in the 

 male, palpi white with pubescence, eyes brown and covered with 

 white hairs, with a frill of longer ones below ; antennae with the 

 3rd joint somewhat elongate-ovate, 4th short inserted at the 

 apex of the 3rd, seta long and pubescent ; thorax and scutellum 

 ver)^ glossy, sometimes bluish or purplish-green ; abdomen pu- 

 bescent, 6th joint purple in the male, apex black, furnished with 

 2 strong horny lobes and 2 long hairy ochreous tilaments (f 7) ; 

 wings short broad and slightly fuscous, costa with a yellow tinge, 

 nervures piceous; halteres and legs ochreous, the latter clothed 

 with black bristles, basal joint of tarsi elongated capitate and 

 hairy above in the male (8) ; tarsi black, excejit at the base, 

 posterior entirely black as well as the tips of the thighs and tibiae. 



