288 A, L. MELANDER. 



66. Male legs with long hairs on outer part; abdomen of male with white pollen. 



teres sp. nov. 

 Legs not plumose ; abdomen dusted with gray serobatica sp. nov. 



67. Not more than six long scutellar bristles; if otherwise, the thorax has four 



broad dark brown vittae 71. 



Generally at least six long scutellar bristles; thorax generally not broadly 

 quadrivittate 68. 



68. Tarsi distinctly annulate aiiiiMlipes Wheeler et Melander. 



Tarsi uniform in color 69. 



69. Abdomen of male with silvery pollen ; legs densely hairy. 



cseligena sp. nov. 

 Abdomen gray or brown pollinose 70. 



70. Femora largely black, densely hairy but not spinose. 



azteca Wheeler et Melander. 

 Femora reddish, spinose below specf abilis Loew. 



71. A long bristle present at the base of the costa Iiianea Coquillett. 



No long costal bristle present 72. 



72. Males 73. 



Females 86. 



73. Legs wholly unarmed, simple 74. 



Armament of legs variously modified 75. 



74. 4 mm.; femora and tibise fuscous apically; central filament of hypopygium 



hidden ; wings narrow steiioptera Loew. 



6 mm.; femora and tibiae reddish ; central filament narrowly visible ; wings 

 normal eno<Iis sp. nov. 



75. Hind trochanters with black spines; hind margins of abdominal segments 



gray 



.76. 



Hind trochanters unarmed 1 1. 



76. Hind tibiae with short bristles oacuiiiiiiifer sp. nov. 



Hind tibiae with moderately long bristles iiiida Loev^. 



77. Apex of hind femora and base of hind tibiaj merely swollen, but with a few 



stiff bristles on inner side iiodipes sp. nov. 



Apex of hind femora and base of hind tibiae provided with strong apophy- 

 ses 78. 



78. The outer process of the hind tibiae large, bifurcate. 



serperastrorum sp. nov. 

 The outer process smaller, not furcate 79. 



79. Abdominal incisures fuscous; posterior tibiae wholly darkened. 



cinerea Bigot. 

 Abdominal incisures not diflerentiated 80. 



80. Inner side of hind femora with an apical longitudinal fringe of black bris- 



tles 81. 



Femora with no fringe 83. 



81. Scutellum with four bristles 82. 



Scutellum with about ten bristles seripes sp. nov. 



82. Scutellum and parts of body yellow clauda Coquillett. 



Wholly black, gray or brown pollinose iuixopolia sp. nov. 



83. Legs slender, reddish ; fore metatarsi elongate ; occiput with but few hairs. .85. 

 Legs short, thickened ; front metatarsi short; occiput densely bristly . . . -84. 



