210 DIPTERA OF NORTH AMERICA. [PART IV. 



Head black ; front broad, with a gray, almost silvery reflection ; 

 antennae of the male more than double the length of head and 

 thorax taken together ; first joint very short ; joints of the flagel- 

 lum long, cylindrical, clothed with a dense, delicate pubescence ; 

 the verticils are hardly perceptible ; the antennae of the female, 

 when bent backwards, would hardly reach the root of the wings ; 

 joints short, oval, the basal ones of the flagellum truncate at the 

 end ; with scattered hairs and inconspicuous verticils among 

 them. Ground color of the thorax black, clothed above with a 

 yellowish-gray pollen, and therefore but faintly shining ; stripes 

 hardly marked ; pleurae somewhat hoary ; halteres yellowish. 

 Coxae yellow ; feet brownish-tawny, pubescent ; femora and tibiae, 

 towards the tip, brownish ; hind tarsi, except the tip, white. 

 Abdomen brown (in some specimens mixed with yellowish) ; 

 male forceps yellow. Wings with a faint brownish tinge ; stigma 

 pale brownish ; tip of the auxiliary vein nearly opposite the inner 

 end of the second submarginal cell ; petiole of the first sub- 

 marginal ce*ll about equal in length to the great cross-vein ; 

 marginal cross-vein faintly marked, close by the tip of the first 

 longitudinal vein ; inner end of the second submarginal cell some- 

 what anterior to the inner end of the first posterior cell ; in some 

 specimens the inner end of the third posterior cell is almost 

 pointed, the cross-vein separating it from the discal cell being 

 very short ; in other specimens, however, this is not the case ; 

 great cross-vein nearly opposite the middle of the discal cell, 

 somewhat variable in its position. 



Bab. Delaware (Dr. Wilson) ; Maryland (Cresson). Three 

 male and one female. The tip of the abdomen of the female is 

 broken off. 



7. L.. teimipes Say. % and £. — Brunnea, humeris pleurisque 

 ochraceis ; anteimis maris thorace multo longioribus, articulis elongatis, 

 pubescentibus ; alae immaculatae, pallide infuscatae. 



Brown, humeri and pleurae oehraceous ; antennae of the male much longer 

 than the thorax ; joints elongated, pubescent ; wings immaculate, with 

 a pale brownish tinge. Long. corp. 0,3 — Q.4. 



Syn. Limnobia tenuipes Say, Journ. Acad. Nat. Sc. Phil. Ill, p. 21, 3. 

 Limnobia humeralis Wied. (non Say), Auss. Zw. I, p. 34. 

 Limnophila tenuipes 0. Sacken, Proc. Ac. Nat. Sc. Phil. 1859, p. 235. 



