389 



ments with anterior marginal bands of a brownish color, which be- 

 come considerably broader from middle to apex of abdomen in male, 

 but are of almost uniform width on all segments in female. Legs pale 

 yellow; apices of tibi?e, of first two tarsal joints, and whole of remain- 

 ing tarsal joints dark brown. Wings clear ; cross vein clouded. Hal- 

 teres yellow. 



Male. — Antenna appreciably longer than head and thorax com- 

 bined, plumes conspicuous and closely placed. Mesonotum with weak, 

 pale hairs between vittse and in front of wing-base ; scutellum with 

 similarly colored, longer hairs. Abdominal hairs pale and rather long ; 

 hypopygium as in Figure 12, Plate XXVIII. Legs slender; fore 

 tarsu9 with basal joint about two thirds as long as fore tibia and as 

 long as next three joints combined ; no long surface hairs on tarsus 

 or mid and hind legs; fourth tarsal joint elongate, subequal in length 

 to fifth. Wing venation very similar to that of culiciformis, apical 

 portion of R3 weak beyond Ro (the cross vein) ; petiole of cubitus 

 subequal to posterior branch of cubitus; surface hairs of wing almost 

 indistinguishable. 



Female. — Similar to male, but with the usual sexual distinctions. 

 The antenna is distinctly shorter than the thorax, the basal joint is 

 much less swollen than in the male, the apical joint is distinctly 

 swollen, and the surface hairs are very short, being barely longer than 

 the diameter of the antennal joints. Body rather stout. In other re- 

 spects similar to male. 



Length, 2.5-3 ^^^ 



Several specimens of this species have been taken at Havana, on 

 the Illinois River, and also at Urbana, during April and May. Ex- 

 amples in the collection of the Bureau of Biological Survey were 

 taken at Washington, D. C, in May and June by W. L. McAtee. 



The larval and pupal stages are described here for the first time. 

 The material was obtained by the writer at Havana. 



This species was originally described from Washington, D. C, and 

 was not known to Johannsen when he wrote his paper, already re- 

 ferred to, on the CJiironoinidcc. 



7. Protenthes riparius, n. sp. 



This species is very similar to the foregoing; in fact so similar 

 that at one time I regarded it as only a color variety of hcllns. The 

 characters separating it from that species are given in the following 

 paragraph. 



Male and Female. — Pale lemon-yellow, opaque; thoracic vittae 

 black, slightly gray pollinose on surface ; abdomen with only the pos- 



