516 



tibiae (25 : 40), hairs on mid and hind legs short; empodium distinct, 

 fringed. Third vein ending just beyond beginning of apical curve of 

 wing; costal vein not projecting beyond apex of third; the cell en- 

 closed by third vein and costal broad to apex; distance from cross 

 vein to apex of first subequal to that from apex of first to apex of 

 third ; cubitus forking appreciably beyond cross vein. 



Length, 3.5 mm. 



Type localitv, St. Joseph, 111., j\Iav 17, 1914, on bank of Salt Fork 

 (C. A. Hart and J. R. Malloch). 



3. Trichocladius politus Coquillett 



Orthocladius poliius Coquillett, Proe. U. S. Nat. Mus., Vol. 25, 1902, p. 93. 

 Trichocladius politus (Coquillett) Johannsen, Bull. 124 (1908), N. Y. State 

 Muf?., p. 283. 



Male. — Head yellow, antennae and palpi fuscous, base of flagel- 

 lum yellowish, plumes brown. Thorax glossy yellow, vittae, a spot in 

 front of and below wing-base, the greater part of sternopleura and of 

 postnotum glossy black. Abdomen brownish or fuscous, the anterior 

 portions of basal two or three segments yellowish. Legs yellow, mid 

 and hind coxae, all femora except at their bases, the apices of tibia? 

 and of first three tarsal joints blackened, fore tibiae and tarsi and 

 apical two joints of mid and hind tarsi generally brownish. Wings 

 clear, veins brown. Halteres clear yellow. 



Antenna about 1.5 times as long as head and thorax together; 

 apical joint of palpi distinctly longer than subapical. Pronotum nar- 

 rowed towards its upper extremity, central excision deep and broad. 

 Hypopygium as in Figure 9, Plate XXXV^H. Legs slender ; fore tarsi 

 without long hairs, basal joint nearly three fourths as long as fore 

 tibiae (30: 43) ; mid and hind legs with distinct, though not long, sur- 

 face hairs; all tarsal claws digitate apically (PI. XXXH. Fig. 9) ; pul- 

 villi indistinct ; empodium present. Third vein ending beyond begin- 

 ning of apical curve of wing, the cell enclosed by it broad and dis- 

 tinct to apex ; cross vein at wing-middle, almost upright, cubitus fork- 

 ing below cross vein. 



Female. — Agrees in color with the male. 



The scape of the antennae is enlarged, the flagellum consists of six 

 joints, the basal two being closely fused and appearing as one, the 

 length of this composite joint being slightly less than that of the next 

 two joints combined (15: 18), the apical joint is much longer than 

 the others, the comparative lengths of apical and subapical joints be- 

 ing as 21 to 8; sensory antennal organs slender, hairlike, placed near 

 apices of the joints; apical joint of palpi distinctly longer than sub- 



