NORTH AMERICAN DIPTERA. 71 



tuft of black pile at the base below ; ovipositor short, black. Legs with white pile 

 and black macrochsetaj ; femora black on the under surface, yellowish red above 

 and at the tips; tibife yellowish red, the hind pair at the end and all the tarsi 

 black. "Wings yellowish hyaline ; the furcation of the third vein unusually far 

 forward, about opposite the middle of the penultimate section of the fourth vein. 

 This description is drawn from fifteen male and ten female specimens 

 from Georgia, North Carolina (from Prof. Comstock), which show but 

 very little variation, and three males and one female from Florida. That 

 it is Macquart's E. lateralis is scarcely at all doubtful, although he speaks 

 of the triangular black spots on the sixth and seventh segment of the 

 abdomen in the male as being large ; that it is also E. amhiguus seems 

 probable, though there are discrepancies, scarcely greater, however, than 

 Macquart was prone to make. The synonomy of E. interruptus with 

 E. amhiguus is given on Osten Sacken's authority. Two male speci- 

 mens from Arizona (from Prof. Comstock ) show no appreciable differ- 

 ence from the Carolina ones. In three of the Florida specimens the 

 femora are wholly black. In some specimens the ground color of the 

 pleurae and sides of the abdomen is in large part red. 



Eras varipes u. sp. 



% . — Length 24-25 mm. Head wholly clothed with white, and densely white 

 pollinose. Antennae black, the third joint not longer than the first. Dorsum of 

 thorax grayish brownish pollinose, the brownish black median stripes distinctly 

 separated through their whole length, only reaching a little ways beyond the 

 suture; clothed with short, sparse black hairs, behiud with white hair andi bristles 

 more or less intermixed with black. Pleurse thickly grayish white pollinose and 

 wholly white pilose. Abdomen black, grayish whitish pollinose and with similar 

 colored pile, the latter not abundant nor long; the second, third, and fourth seg- 

 ments, when seen from behind, with a large transverse spot more shining in front, 

 faintly divided in the middle by brownish pollen ; posterior part of the fifth, and 

 the two following segments bright silvery-white. Hypopygium black, with black 

 and white pile. Legs red; the under side of all the femora, broadly, and the 

 inner side of the tibiffi black, the tarsi darker red or blackish ; bristles chiefly 

 black, pile white, the inner side of the tibiee, especially of the front pair with long 

 abundant white hair. Wings hyaline, anterior cross-vein near the middle of the 

 discal cell, the furcation of the third vein only a little beyond it. 



Two specimens, Arizona (Prof. Comstock), Western Kansas (Gruild). 



The legs will probably vary in coloration. 



Erax Bastardii. 



? Asiluif aestuans Linne, Syst. Nat. ii, 1007, 6; Amoen. Acad, vi, 413, 95; Fab- 



ricius, Syst. Ent. iv, .379, 8. 

 ? Asilus macrolabis Wiedemann, Auss. Zw. Ins. i, 45S, 51. 

 Erax femoratus Macquart, Dipt. Exot, i, 2, 115, 20. 

 Erax incisuralis Macquart, Dipt. Exot. i, 2, 117, 24. 



Erax Bastardii Macquart, Dipt. Exot. i, 2, 11 7, 25 ; tab. 9, fig. 7 ; Riley, 2d Rep. 124. 

 Erax tibialis Macquart, Dipt. Exot. i, 2, 118, 27. 



