NORTH AMERICAN DIPTERA 69 



Erax anoinalns 



Ei-a.c anomalus Bellardi Saggio, etc., ii, 32 ; tab. ii, fig. 7. — Mexico. 



^ .—Length 20-25 mm. Face densely light yellowish pollinose, the gibbosity 

 and oral margin thickly clothed with yellowish white hair and bristles; in profile 

 there is a short, deep concavity below the antennse. Antennae black, the first two 

 joints with short white hairs, the third joint scarcely longer than the first ; bristles 

 as long as the antennse, black. Front deeply excavated below the eyes, narrowed 

 above, clothed with white hairs and bristles, except a few black bristles on the 

 ocelli. Occipito-orbital bristles black, the beard and hair of the proboscis silky- 

 white. Thorax black; the humeri and spots on the pleurae reddish; the two usual 

 dark stripes of the dorsum are apparent; in front of the suture the dorsum is 

 clothed only with short black hairs, on the posterior part with sparser white and 

 black hair and black bristles. Scutellum on its dorsum with white pile, along its 

 bordej- with about twelve black bristles. Pleurae thickly whitish pollinose and 

 with sparse white hair. Abdomen black, the swollen hind border of the first 

 segment red on its sides ; above wholly and thickly clothed with long silky-white 

 pile, parted down the middle and combed outwards, nearly wanting in the middle 

 of the first and second segment; second segment with a large oval blackish spot 

 in front and the third segment with a smaller one ; elsewhere (except the first 

 segment) the dorsum is covered with dense white pollen. Venter also with long, 

 but sparse, white pile. Hypopygium very large, chiefly red, thickly clothed with 

 black and white pile. Legs deep red ; front and middle femora and often the hind 

 pair also, except the posterior surface, and the tip of hind tibiae, black ; pile white, 

 long and abundant on the inner side of the tibiae ; macrochaetae black. Wings 

 hyaline; three sub-marginal cells; the furcation of the third vein takes place a 

 little distance before the distal end •£ the discal cell, the nervure connecting with 

 the second vein short, scarcely longer than the cross-vein at the distal end of the 

 fourth posterior cell. 



5. —Abdomen black, clothed with short sparse white pile. First segment yel- 

 lowish whitish pollinose; the ground color red behind as in the male, the follow- 

 ing segments broadly whitish pollinose on the sides, extending across on the pos- 

 terior margin, in the middle broad, when seen obliquely from behind, seen from 

 in front a large semi-circular black spot occupies the chief part of the segment, 

 but is of a brownish cast behind. Ovipositor moderately long black. Tibite with- 

 out the abundant silky pile on the inner sides. 



Eight males and seven females from Arizona (Prof. J. H. Comstock, 

 E. L. Keen). 



Erax leucocoiiius n. sp. 



% ^ . — Length 25 mm. Mystax and hair of the head throughout nearly white ; 

 face and front densely yellowish white pollinose ; the concavity of the face below 

 the antennai is short and deep. Antennae black, third joint scarcely longer than 

 the first. Thorax black, thickly whitish yellowish pollinose ; the dorsum before 

 the suture clothed with short, erect, black hairs, on the posterior part and on the 

 scutellum with whitish hair and light yellow bristles; the two median longitudinal 

 stripes are slender, brown, separated by a pollinose interval through their whole 

 length, not broader than the stripes behind, twice or thrice as broad in front. 

 Pleurae densely whitish pollinose, and with white pile. Abdomen black, the hind 

 margins of all the segments yellowish red, everywhere rather thickly covered with 

 whitish pollen and recumbent whitish pile, an oval sj^ot near the middle of each 



