493 



A male from Monticello has the basal joint of fors tarsi more than 

 one third longer than the fore tibiae, but in other respects agrees with 

 the foregoing description. 



Originally described from Ithaca, N. Y., and Washington State. I 

 have seen specimens from Lafayette, Ind. (Aldrich), Plummer's 

 Island, Md. (McxA.tee), and from Niles, Mich. (Hart). 



lo. Tanytarsus flavicauda, n. sp. 



Male. — Differs in color from ohediens in having the flagelUmi and 

 plumes of the antennae and also the palpi yellowish, the abdomen 

 without yellow posterior margins to the segments, and the apical por- 

 tion of lateral arm of hypopygium pale yellow. 



Structurally the species are similar, the principal distinctions being 

 found in the hypopygium, the apical portion of the lateral arm in fiavi- 

 caiida being much longer than the basal portion, whereas in ohediens 

 it is slightly shorter. 



Female. — Similar to the female of ohediens, but differing in that 

 the segments of the abdomen are without pale posterior margins. 



Length, 3-4 mm. 



Type locality, Carbondale, 111., April 23, 19 14. Paratypes from 

 Illinois River at Havana. April 29, 1914 (C. A. Hart and J. R. Mal- 

 loch). 



Early stages unknown. 



II. Taxvtarsus politus. n. sp. 



Male. — Greenish yellow, shining. Head yellow ; antenna;, with 

 the exception of the base of flagellum, fuscous; palpi brown. Vitta? 

 glossy blackish brown; lower part of sternopleura and greater part of 

 postnotum concolorous with vittse. Abdomen generally unicolorous 

 brown, but sometimes with only the apices of segments of the basal 

 half and the whole of the segments of the apical half brown. Legs 

 pale brown, fore femora and tibia usually darkened. Wings clear, 

 veins and surface hairs brownish. Antennal plumes and surface hairs 

 on legs pale brown. Halteres greenish white. 



Length of antennae more than one and a half times that of head 

 and thorax together. Pronotum of moderate breadth ; mesonotum but 

 slightly produced anteriorly. Hypopygium similar to that of dives, 

 the only appreciable difference lying in the shorter and broader exten- 

 sion of' the dorsal plate. Legs rather slender; fore tarsi without long 

 hairs, basal joint a trifle less than one half longer than fore tibiae 

 (48: 33) ; mid and hind legs with moderately long hairs. Third vein 



