NATURAL SCIENCES OP PHILADELPHIA. 243 



wings ; the third joint is the longest ; the sixth is very short, almost rudi- 

 mental. Thorax cinereous, with a brownish, cuneiform, axillary intermediate 

 stripe, and two lateral stripes, which are abbreviated before and extended 

 over the scutum behind ; metathorax cinereous ; halteres pale at the base ; 

 knob blackish ; feet black, base of femora tawny. Abdomen blackish ; ^ 

 genitals black ; 9 ovipositor very short, brownish. Wings subcinereous, 

 veins black ; subcostal area tawny ; neuration like Meig. i. tab. vii. f. 8. 



Two (^ specimens from Washington, D. C, and one 9 from Maryland ; 

 early in the Spring. 



Eeioceba Macq. 



Front with a tubercle behind the antennae. Antennae rather short, nearly 

 of the same length in ^ an( i 9) six (or seven) jointed ; third joint twice as 

 long as the fourth. Proboscis short ; palpi nearly as long as the head ; second 

 and third joints of about the same length ; the last joint about twice as long. 

 Eyes remote, naked. Feet long, moderately stout, tibiae with distinct spurs ; 

 tarsi with distinct pulvilli. Wings with two cubital arese and no petiolate 

 areolet (somewhat. like Meig. i. tab. v. f. 4.) Forceps of the ^ very much 

 like that of Arrhenica (see fig. 31.) Ovipositor of the $ of moderate 

 length. 



Eriocera is closely allied to Arrhenica, but is distinguished by the 

 antennas, which are short in both sexes, and by the structure of the palpi. 



Macquart founded 'this genus in 1838, on a Brazilian species. (Dipteres Ex- 

 otiques i. i. p. 74.) 



E. fuliginosa. Nigro-fusca : basi antennarum et pedibus fulvo-ferrugi- 

 neis ; apice femoram^ tibiarumque nigra ; alis nigro-fuscis ; length 4-5 lin. 



Lower part of the head and proboscis tawny ; palpi black ; antennae black; 

 basal joints yellowish ferruginous. Thorax dull brown with a slight grey re- 

 flection ; four brown more or less distinct stripes on this grey ground : halteres 

 brown ; feet ferruginous, tip of femora and tibiae brown, tarsi brown. Abdo- 

 men brown, shining ; male forceps tawny (see fig. 31) ; female ovipositor fer- 

 ruginous tawliy at the base. Wings brown, clouded along the veins ; stigma 

 darker brown. 



Nine male and one female specimens from Berkely Springs (Va.) and Wash- 

 ington, D. C. 



I possess two male specimens from Virginia, which are very different from 

 the normal ones. The whole body is cinereous ; the stripes on the thorax are 

 more distinct ; the wings are pale brownish. It is not impossible that they 

 belong to a different species. 



Arrhenica nob. 



Front with an abrupt tubercle behind the antennas. Antenna of ^ 6-jointed, 

 more than twice as long as the body, with a row of small, erect spines on the under 

 side ; those of the $ not longer than the thorax, 10-jointed, the last joint being 

 then indistinct. Proboscis much shorter than the head. Palpi longer than 

 the proboscis, sometimes longer than the head ; the second and fourth joint 

 are much longer than the third. Eyes remote, naked. Feet long, tibiae with 

 distinct spurs ; tarsi with distinct, well developed pulvilli. Neuration of the 

 wings like that of Limnophila; with two radial area? and with or without 

 petiolated areolet. Forceps of the tf somewhat similar to that of Limno- 

 phila, consisting of an elongated, subcylindrical basal piece with two falci- 

 form appendages (see fig. 30, and detailed description appended to it.) Ovi- 

 positor of the $ elongated in A. spinos a, short in A. longicornis. 



The long antennab of the <^Arrhenica remind us of the genus M e g i s t fl- 

 ee ra Wied., but these genera differ: 1st, by the antenna: of the 9 which are 

 long in the species described by Wiedemann ; according to him they are 10- 



1859.] 



