226 THE CANADIAN ENTOMOLOGIST 



Third antennal joint at least four times as long as 



second 2. 



2. Hind femora of male with a comblike fasciculus of short, stiff 

 bristles at base of ventral surface; abdomen in both sexes 

 with a pair of large subtriangular black spots on dorsum of 

 segments 2 to 4; veins 3 and 4 of wings convergent apically ; 

 antero-dorsal surface of hind tibia with 1 bristle in 

 female (Cal.) femorata Malloch 



Hind femora of male without a fasciculus at base; abdomen 

 in both sexes with a faint central line; veins 3 and 4 of 

 wings subparallel; antero-dorsal surface of hind tibia with 

 3-4 bristles (Mass., Tex.) unica Stein 



Tetramerinx brevicornis, sp. n. 



Female. — Length 4 mm. Black, densely covered with yel- 

 lowish gray pruinescence. Frons yellowish gray with the excep- 

 tion of an opaque, black, wedge-shaped mark on each side at apex 

 of frontal triangle; antennae and palpi black. Thorax unmarked. 

 Abdomen with very faint indications of a pair of spots on dorsum 

 of segments 2 and 3. Legs black. Calypterae white, yellowish on 

 margins. Halteres yellow. Wings clear, veins yellowish. 



Frontal triangle very broad, obscuring central stripe on 

 posterior half; each orbit as broad as central stripe, the bristles 

 nearer inner than outer margin, a series of short setulae laterad of 

 the bristles; frons and face distinctly protuberant; third antennal 

 joint about twice as long as second; arista swollen on basal fourth, 

 very shortly pubescent; marginal bristles on cheek sparse; cheek 

 one-fifth as high as eye, the latter nearly twice as high as long. 

 Thorax very sparsely haired; acrostichals irregularly 2-rowed. 

 Abdomen without strong bristles except at apex. Fore tibia with 

 or without a weak bristle; mid tibia with 2 weak posterior bristles; 

 hind tibia with 4-5 antero-dorsal and 2 antero-ventral weak 

 bristles. Inner cross-vein distinctly beyond middle of discal cell; 

 outer cross-vein almost straight; veins 3 and 4 subparallel apically. 



Type locality, Waukegan, 111., August 23, 1906. Taken on 

 shore of Lake Michigan. Two specimens. 



Type in collection of Illinois State Laboratory of Natural 

 History. 



