34^ 



PSrCHE. 



[May iSqo. 



dust. Cilia of the tegulae black. Scutellum 

 concolorous with the thoracic dorsum. Ab- 

 domen metallic green, passing into cupreous 

 on the apical half; venter dusted with white, 

 its short hairs pale vellow; hjpopygium 

 large, black, with metallic green reflection 

 on its basal half, thinly covered with white 

 dust; penis and internal appendages pale 

 yellow; lamellae white, of moderate size and 

 irregularly trigonal shape ; apical mar- 

 gins rather broadly bordeied with black and 

 broken into a jagged fringe of bristles, which 

 seem to be white with black bases. From 

 the posterior edge of each lamella projects a 

 broad, flat, bifurcate bristle. Coxae and legs 

 pale yellow; the latter dusted with silvery 

 white dust. Fore coxae covered with short 

 white hairs anteriorly and bearing several 

 conspicuous black bristles near their tips; 

 the median coxae have, besides a few long and 

 curved black hairs on their anterior faces, a 

 long and straight black seta on the lateral 

 face near the tip and a brown spot at the base ; 

 hind coxa near its tip with a black bristle 

 which is only about f as long as the corres- 

 ponding one on the median coxa. Fore tar- 

 sus plain, about \\ times as long as the fore 

 tibia, the last joint but very slightly, if at all, 

 dilated, black, contrasting with the pale yel- 

 low of the other tarsal joints. Posterior fem- 

 ora each with a prominent preapical bristle; 

 the hind pair eciliate ; the black bristles of 

 the posterior tibiae well developed and con- 

 spicuous ; median tibiae with four equal setae 

 at their tips; posterior tarsi blackened from 

 the tip of the first joint; usually on the me- 

 dian pair the second joint and the tip of the 

 first are more dark brown, Halteres pale 

 yellow. Wings hyaline, with a brownish 

 tinge; narrow at their bases and somewhat 

 pointed at their apices; veins yellow; one 

 or both of the angles of the double flexure in 

 the fourth longitudinal vein somewhat more 

 acute than in many species of Dolic/iopus. 

 The posterior cross-vein, though perpendicu- 



lar to the fourth longitudinal vein, forms an 

 angle less than 90" with the fifth longitudinal 

 vein. 



$. Length 4.5 mm.; length of wing 4.5 

 mm. 



Face twice as broad as in the male. Third 

 antennal joint infuscated to a less extent and 

 ending in a slightly shorter and blunter 

 point. The terminal joint of the fore tarsus 

 seems to be a little narrower than in the 

 male, though it is also accentuated with black. 

 Otherwise the female very closely resembles 

 the male. 



Habitat: Milwaukee Co., Wis. 



I have examined 15 males and 18 fe- 

 males of this species and, with a single 

 exception, find the coloring approxi- 

 mately constant as I have descrihed it. 

 The species is closely allied to Loew's 

 D. variabilis^ in whose company I 

 have several times taken it. The males 

 of the two species may, however, be 

 readily separated by attending to the 

 following points : 



D. variabilis : Face yellow ; cilia 

 ofthetegulae yellow; fore tarsi black- 

 ened from the tip of the first joint ; 

 hind femora ciliated. 



jD. germaitus : Face white; cilia 

 ofthetegulae black; only the terminal 

 joint of the fore tarsi black ; hind femora 

 eciliate. 



The pale hairs on the ventei- of the 

 male specimens of variabilis in my 

 possession are very much longer than 

 in germainis. The hypopygial la- 

 mellae, too, have a difierent outline and 

 more jagged edge with several flattened 

 bifurcate bristles. The females of the 



