THE CANADIAN ENTOMOLOGIST. 201 



thickened nearly to the middle ; thorax gray pruino.se, marked with five 

 black vittae, the three median ones reaching slightly beyond the suture 

 and appearing confluent when viewed from behind, three pairs of post- 

 sutural dorsocentral bristles, two sternopleurals, scutellum gray pruinose, 

 the sides broadly velvet black, abdomen gray pruinose, the first three 

 segments with a transverse row of five velvet black spots, broad apex of 

 the fourth segment polished, second and third segments with a marginal 

 pair, the fourth with a marginal row of bristles ; first joint of front tarsi 

 shorter than the second and greatly thickened, the lower outer angle 

 bearing a cluster of rather long yellow bristly hairs, pulvilli 01 e-third as 

 long as the last tarsal joint, hind tibiae outwardly somewhat abate with 

 bristles of an unequal length ; wings hyaline, a small brown spot at apex 

 of first vein, a larger one at small crossvein, prolonged toward apex of 

 discal cell, a narrow one in outer lower corner of this cell, a large spot at 

 apex of second vein and on bend of fourth vein, the latter furnished with 

 a rather long appendage, the vein beyond it nearly straight, terminating a 

 short distance before the extreme tip of wing ; length, 5 mm. Four 

 specimens collected May 31st. 



Habitat. — Sierra Madre, Chihuahua, Mexico (head of Rio Piedias 

 Verdes, altitude about 7,300 feet). 



Type.— Cat. No. 6299, U. S. N. M. 



Family Dexid.k. 

 Trixodes, new genus. 



Head in profile nearly hemispherical, front rather prominent, face 

 strongly retreating below, facial depression nearly elliptical in outline, a 

 rather low, broad median carina, vibrissa? absent, vibrissal angles widely 

 separated, situated the length of the antennae above the anterior oral 

 margin, ridges bare, antenna? less than one-fourth length of face, the 

 second and third joints of nearly an equal "length, arista bearing a few 

 hairs, the longest of which are nearly twice as long as greatest diameter 

 of arista, penultimate joint of the latter as broad as long, frontal bristles 

 descending nearly to middle of second antennal joint, ocellar and pcst- 

 ocellar bristles small or wanting, only one pair of verticals, sides of face 

 on upper half bare, the remainder and the cheeks sparsely covered witti 

 short bristly hairs, cheeks four-fifths as wide as the eye-height, eyes bare, 

 proboscis one-fourth as long as height of head, rather robust, labella 

 small, palpi short clavate ; bristles of tibia? very short, hind tibiae not 

 ciliate with bristles; third vein bristly on the basal fourth of first section, 



