OF WASHINGTON, VOLUME XVII, 1015 !)< 



beyond second basal cell, bend of fourth vein destitute of stump 

 or wrinkle, fourth vein beyond the bend curved gently inward. 

 The two species may be easily separated as follows: 



First Vein with at most two or three widely separated setulae 

 on outer third, third joint of antenna black, gently concave on 

 its front edge, arista shorter than third antennal joints (fig. 1-2), 

 : slossonce Coq. 



First Vein bearing setula3 to the number of six or seven on its 

 intermediate third only, third antennal joint in part yellow, 

 gently convex on its front edge, arista longer than third antennal 

 joint (figs. 3-4), = : johnsoni Coq. 



HOMALACTIA Townsend. 



Palpi present well developed (fig. 5) ; first vein thickly setulate 

 on its outer two-thirds, third vein setulate to a point considerably 

 beyond small crossvein, fifth vein bearing three or more bristles 

 just beyond second basal cell (fig. 6); lower half of face on sides 

 bare, frontal bristles strongly developed, descending to base of 

 arista, the lowest ones curving upward (fig. 5); proboscis not 

 longer than height of head, fleshy. Apical cell ending close to 

 wing tip, either open or closed and short petiolate. Fourth vein 

 bent violently inward beyond the bend which bears a short stump 

 directly in line with the fourth vein before its bend. Third 

 antennal joint subdentate on its lowest front corner. Ocellar 

 bristles directed forward, head shorter at vibrissse than at base 

 of antennae. Vibrissse on oral margin; eyes thinly hairy; front 

 tarsi of female distinctly dilated, hind tibia& not ciliate. 



Type: Exoristoides harringtoni Coq. (figs. 5-6). 



In describing this unusually marked species 1 Mr. Coquillett 

 had before him but one specimen which is at present in a poor 

 state of preservation. It differs from the specimens before me 

 in having the apical cell closed and petiolate. The original de- 

 scription of the type makes no mention of the presence of a row 

 of several bristles on the fifth longitudinal vein near its base. The 

 occurrence of these is a rare thing in the TachiimUo. They arc 

 found in Polychcetoneura elyii Walton, and Chcetoplagia atripeinrix 

 Coq. and in a few other genera. The latter fact was overlooked 

 in my description of Polychcetoneura but in no-wise affects its 

 standing as Chcetoplagia belongs to that group possessing a row 

 of macrochsetae on the face. 



1 Proc. F. S. Natl. Mas., Vol. XXV, p. 110. 



