395 



of all tarsi brown, all tarsi from apices of second joint obscured with 

 brown. Wings clear, cross vein distinctly infuscated. Halteres yellow. 



Male. — Antenna as long as head and thorax together, basal joint 

 much swollen, last joint about one and a half times as long as rest of 

 flagellum, plumes very long and dense. Mesonotum almost bare, the 

 hairs between vittse very weak ; a small group of rather short hairs 

 close in -front of wing-base. Abdomen with quite long and rather 

 numerous pale hairs; hypopygium as in Figure 6, Plate XXVIII. Legs 

 rather slender and without long hairs ; basal joint of lore tarsus about 

 two thirds as long as fore tibia and distinctly longer than the remain- 

 ing joints combined ; fourth tarsal joint of all legs obcordate. Wing 

 venation as in preceding species. 



Female. — Structurally almost identical with the female of the pre- 

 ceding species. 



Length, 4.5-5 mm. 



Illinois localities: Urbana, July 2, 1887 (C. A. Hart), and Sep- 

 tember 5, 1914 (J. R. Malloch) ; Havana, August and September, sev- 

 eral of the speciments at light. Larvae occur commonly in the Illinois 

 River as far north as Ottawa, and in the numerous connected lakes. 



Originally described from Tick Island, Fla., and not subsequently 

 recorded as far as I am aware. 



PsiLOTANYPUS Kiefifer 



As far as our present knowledge goes, this genus is represented in 

 North America by only a single species, occidentalis Coquillett. The 

 immature stages are unknown. 



PSI1.0TANYPUS occiDENTAUS Coquillett 



Tanypus occidentalis Coquillett, Proc. U. S. Nat. Mus., Vol. 25, 1902, p. 92. 



Male. — Brownish black, subshining. Head fuscous, including the 

 antennae and their plumes, face yellowish. Pronotum, anterior mar- 

 gins of mesonotum, upper central portion of pleurae, and scutellum 

 yellowish. Venter of abdomen yellowish, dorsum black. Legs brown- 

 ish, tibiae and tarsi, except their apices, paler. Wings clear, veins 

 brownish. Halteres yellow. 



Pronotum rather wide, central excision weak. Hypopygium with 

 distinct, acute extension of dorsal plate, apical portion of lateral arm 

 recurved. Legs slender, fore tarsi with moderately long sparse hairs, 

 basal joint four fifths as long as fore tibiae; fourth tarsal joint on all 

 legs linear, longer than fifth ; pulvilli absent ; empodium small. Vena- 



