NORTH AMERICAN DlPTERA. 



HETEROPEZIN^. 



A A. 54. Two joints in the tarsi, the first shorter than the second; 

 no palpi; with two or three longitudinal veins. 



Oligarces Mein. 



55. Tarsi with three joints, the first longest; two longitudinal 



veins ........ Heteropeza. 



56. Tarsi with four joints, first longer than second; three lon- 



gitudinal veins; palpi with two joints. Miastor Mein. 



57. Tarsi with five joints, first shorter than second; wings acu- 



minate at extremity; palpi three-jointed; three longitud- 

 inal veins. , ..... Pero Mein. 



58. Like preceding, palpi two-jointed, third longitudinal vein 



evanescent before extremity. . . . Firenia K. 



59. Like Firenia; palpi single jointed. . Leptosyna K. 



60. Tarsi with five joints, the first longer than second; scales 



of wings long and striated. . . Lasiopteryx W. 



61. Like preceding, but tarsi with four joints and neuration as 



in Perrisia. ..... Ledomyia K. 



62. Like Ledomyia, but first joint of tarsi shorter than second; 



fifth vein simple. . . . Brachyneura Rond. 



LESTREMIN^. 



AAA. First joint of tarsi longer than the second; fourth longitudinal 



vein present. 

 H. Fourth vein simple; fifth furcate near its middle. 



63. Flagellum in the male with twelve joints, in the female 



with nine; palpi with three or four joints; claws simple. 



Joarmisia K. 



64. Male flagellum with twelve, female with eleven, palpi with 



two joints. ...... Peromyia. 



65. Claws denticulate; no empodia; antennal joints long-petio- 



late. ....... Wasmaniella K. 



66. Claws as in Peromyia; palpi four-jointed; antennae as in 



Pr ion el I its. . . . . Bryomiya K. 



67. Claws denticilate; empodia large; flagellar joints of male 



antennae excentric. .... Prionellus. 



68. Like Prionellus, but the claws not denticulate, and the 



empodia short or rudimentary. . . Aprionus K. 



69. Like Aprionus but the claws denticulated. Monardia K. 



70. Antennae very short, composed of ten or eleven joints in 



the male and from six to eight in the female; joints not 

 petiolate in either sex. . . Micromyia R. 



71. Antennae with about twelve flagellar joints in the male, 



from ten to twenty-three in the female. Campylomyza 



