AMERICAN DIPTERA. 229 



Tachydroinia clavipes Loew. 

 Cent,, V, 73. 



Black, shilling; legs including coxse largely black, apex of anterior tibiae 

 strongly incrassate, wings beyond the whitish base dark, provided with a poste- 

 rior basal cross-vein. Antennae dark fuscous, proboscis black, palpi white. 

 Hypopygium with short black hairs above. 2.6 mm. 



Illinois (Le Barou). 



^ Tachydroinia pusilla Loew (Fig. 51). 

 Cent., v, 74. 



Shining, black, proboscis and palpi concolorous, no white spot on the pleurae ; 

 coxae yellow; anterior legs yellow, except the upper side of the femora and tibiae 

 and the whole of the tarsi ; middle legs like front ones, except that the whole of 

 the tibiae is piceous, femora beneath with black setulse ; hind legs, except lute- 

 ous base of the femora, piceous. Wings cinereous, outer half of costal margin 

 infuscated, no posterior cross-vein. 2 mm. 



Illinois (Le Baron), Snow, Wheeler; Massachusetts (Hough). 



Taf^hydromia rostrata Loew. 

 Cent., V, 72. 



Black, antennae yellowish, palpi white, proboscis yellow, except tip. Thoracic 

 dorsum subopaque, pleurae shining. Coxae yellow; legs yellow, posterior femora 

 and all the tibiae partly fuscous ; middle tibiae before apex slightly eniarginate. 

 This emargination is not readily seen. Wings subfuscous, whitish basally, with 

 a posterior cross-vein. 3 mm. 



Hew Hampshire. 



Tachydromia rapax Loew (Fig. 55). 

 Cent., V, 71. 



Black ; wings subfuscous, at base whitish, with a posterior cross-vein. Coxae 

 yellow, with a black spot, trochanters black beneath, anterior femora with an 

 apical dot on posterior side, united on under side to a basal dot on the anterior 

 side; front tibiae fuscous, apical third of posterior tibiae dark; middle tibiae 

 excised before apex. 3 mm. 



Illinois (Le Baron). 



Specimens of this species are in the collection from Massachu- 

 setts, Indiana, Illinois, Wisconsin and Wyoming. 



COLOBORfEURA gen. nov. 

 Thick set. Head globose, longer than wide, wider than deep; 

 eyes small, two thirds the head height, inserted forwards and there 

 fore the occiput large; three ocelli present, the posterior two ap- 

 proximated ; occiput with stiff black bristles, longer on the upper 

 vertex and between the ocelli ; front narrowed mid-way between the 

 ocelli and the antenna; eyes notched at the antenna; distance from 

 the antennae to the bottom of the labrum equal to that from the 



TRANS. AM. ENT. SOC, XXVIII. JULY, 1902 



