412 



Antennae with 8 joints, the constriction between the joints not 

 deep. Pronotum continued rather broadly ahnost to the level of the 

 mesonotum, central division rather wedge shaped ; pruinescence on 

 mesonotum white and conspicuous, especially on anterior lateral 

 angles ; surface hairs sparse ; scutellum convex. Fore tarsus with basal 

 joint about two thirds as long as tibia. Cubitus forking below cross 

 vein. 



Length, 3-4.5 mm. 



Illinois locality, Momence, July 17, 1914, at light (C. A. Hart). 



I have not seen the male, which is described by Johannsen. Two 

 females sent me by him, labeled Ithaca, N. Y., agree with the female 

 described here except that the colors are less sharply contrasted and 

 the basal joint of the fore tarsus is rather more than two thirds the 

 length of the tibia. 



I have some doubt as to specific distinction between ohscura and 

 platypus Coquillett, but only an examination of the type of the latter 

 could satisfactorily settle the point. 



Thai^assomyia fulva Johannsen 



Thalassomyia fulva Johannsen, Bull. 124, N. Y. State Mus., 1908, p. 275. 



Female. — Yellow, slightly shining. Head yellow; last joint of an- 

 tennae and palpi fuscous. Mesonotum with three reddish vittse; 

 pleurae slightly reddish; posterior half of postnotum brownish. Legs 

 yellow, apices of tarsi slightly infuscated. Wings clear, veins yellow. 

 Halteres yellow. 



Antenna short, basal 2 joints of flagellum wdth slight constriction 

 between them, the others distinctly moniliform. Pronotum broad, the 

 central emargination broad and shallow ; no pruinescence and very few 

 hairs on mesonotum. Legs slender but not very long; basal joint of 

 fore tarsus slightly more than half as long as tibia (24:40) ; fourth 

 tarsal joint very distinctly shorter than fifth but not obcordate. Cubi- 

 tus forking almost directly below cross vein. 



Length, 2.5 mm. 



Illinois locality, Dubois, April 24, 1914. Swxpt from vegetation 

 on bank of creek (J. R. Malloch). 



Johannsen described fiilva from Old Forge, N. Y. I have a slight 

 doubt as to the generic position of this species since the fourth tarsal 

 joint, though shorter than the fifth, is not obcordate. In other re- 

 spects the species closely resembles obsciira structurally. 



The early stages are undescribed. 



