NATURAL SCIENCES OP PHILADELPHIA. 247 



Head cinereous, with a golden pubescence ; palpi brown, pale at base ; an- 

 tennae brown, three or four basal joints pale ; first joint cylindrical ; second 

 cyathiform ; third smaller, obconical ; joints from fourth to tenth short, cylin- 

 drical, compressed, gradually attenuated, covered with short hairs ; the last 

 part of the antennas is filiform, with long verticils; eyes distinctly pubescent. 

 Oollare pale, with a brown spot : thorax cinereous, with three brown stripes ; 

 intermediate one broad, splitting in two lobes before the scutum, which is 

 brownish ; scutellnm and metathorax cinereous ; pleurae cinereous ; halteres 

 pale ; coxae pale ; feet pale tawny, tips of the femora fuscous ; those of the 

 tibiae and tarsi infuscated; spurs at the tip of the tibiae moderately long, very 

 distinct. Tergum brown, with a sparse golden pubescence; venter pale. Wings 

 infumate topazine, their surface shining; subcostal area faintly yellowish: 

 central cross-veins, stigmatical cross- vein, tip of mediastinal vein and origin of 

 petiole clouded ; the radial vein forks (as usual), but the petiole of its fork is 

 so short, that the second radial is almost equal in length to the cubital ; stig- 

 matical cross-vein at the tip of subcostal vein; the first lower discal cross-vein 

 is situated at about the middle of the distance, between the origin of the two 

 forks, which it unites ; stigma pale. 



One tf specimen from Massachusetts, (Mr. Scudder.) 



A. calcar. Ochracea, fronts cinerea; alis pallide cinerascentibus ; area 

 subcostali flavescente, stigmate pallido ; calcaribus tibiarum longioribus ; long, 

 lin. 4J 5. 



Front and vertex cinereous, proboscis yellowish cinereous, palpi yellow at 

 base, two la3t joints brown ; antennae yellowish ferruginous, infuscated at tip, 

 reaching about half the distance between the head and the base of the wing ; 

 second joint obconical ; the following joints subcylindrical, moderately verti- 

 cillated and covered with a dense pubescence ; eyes pubescent. Thorax ochra- 

 ceous yellow, reddish on praescutum ; stripes iudistinct ; pleurae, scutum, 

 scutellum and metathorax paler, halteres pale ; feet yellowish tawny, infuscated 

 towards the tip; coxae and base of femora pale; spurs at the tip of the 

 tibiae longer than usual, slender, divaricated. Abdomen yellowish, (infuscated 

 at the tip in the ^.) Wings hyaline ; slightly cinereous ; subcostal area yel- 

 lowish, stigma pale ; second radial area longer than the cubital (the cubital and 

 not the radial vein forming the fork), and of nearly the same length with the 

 subapical area; radial vein arcuated before joining the petiole ; stigmatical 

 cross-vein near the tip of the subcostal vein. 



In both specimens in my possession the discal areolet is wanting on one wing 

 and extant on the other; what the normal neuration is, I am unable therefore 

 to state. On those wings where it is wanting, (which happens to be the left 

 wing in the tf specimen and the right in the 9 >) the neuration looks pretty 

 much like Meig. i. tab. v. f. 8. The cross-vein closing the areolet on the other 

 wing is in the middle of the distance, between the origins of the second and 

 third fork. 



A. inconstans. Ochracea, thoracis dorso ferrugineo, alarum margine 

 anteriore et venis transversis infuscatis ; long lin. 4^ 5 \. 



Coloring very inconstant; ochraceous, more or less mixed with brown on 

 the thorax and the abdomen, sometimes altogether without brown. The fol- 

 lowing is the description of the specimens with fully developed dark coloring : 



Proboscis and palpi fuscous ; front cinereous, brownish towards the vertex; 

 hind part of vertex and under side of the head yellowish ; antennae 17-jointed, 

 pale, but little longer than the head ; basal joint sometimes dusky; flagellum 

 with moderate verticils. Collare ochraceous ; a black ring near the head ; 

 a brown stripe along the middle ; praescutum ferruginous, with a slight brown 

 tinge along the middle; stripes indistinct; scutum infuscated on both sides; a 

 brown mark in the shape of a V in the middle of the suture ; scutellum and 

 metathorax yellow, fuscous on both sides ; pleuras pale ; halteres pale ; feet 



1859.] 



