134 DIPTERA. 



costa, at the end of the first submarginal cell, which exists in A. sinuosa, is wanting 

 here. The pulvilli are distinct. 



26. Anthrax ?, $ . 



Sab. Mexico, Northern Sonora (Morrison). 



Characters of Anthrax (sensu stricto), as defined above. The black ground-colour of 

 the abdomen partly hidden under a yellow tomentum ; the latter forms a conspicuous cross- 

 band on the hind margin of the first segment, and the other segments seem to have been 

 entirely covered by it, the bare and therefore black spaces being, apparently, abraded; 

 nevertheless, the black cross-bands on the anterior portions of segments 2 and 3 are in 

 part clothed by a black scaly tomentum ; the sides of the abdomen beset with a fringe 

 of black hairs, which begins in the middle of the second segment ; the sides of the first 

 segment have whitish hair ; venter black, with yellow hair. Thorax with a yellow 

 tomentum ; on each side a stripe of whitish-yellow hairs, passing from the humeri 

 above the root of the wings. Head with a yellowish-red tomentum and the usual black 

 erect pile on the front ; vertex with a fulvous tomentum. Halteres brown. The dark 

 brown antero-proximal half of the wings is very much like that of A. eumenes, except 

 in the anal and axillary cells : in the anal cell the brown does not reach beyond the proxi- 

 mal end of the fourth posterior cell ; in the axillary cell it occupies a portion of the 

 proximal half only, and does not reach the margin. Length 7 millim. (it is very probable 

 that larger specimens occur). A single female. 



N.B.— The pulvilli are small, but distinct. I cannot see the spinules on the front 

 tibiae ; but the specimen is not well preserved. — This insect must be very near A. bigra- 

 datus (Loew, Centur. viii. no. 37, Cuba), but I cannot identify it with certainty. 



Subgenus Hyalanthkax. 



Front tibia? sometimes provided with spinules, sometimes smooth ; front tarsi not 

 unlike those of Anthrax sensu stricto, rather stout, provided on both sides with the 

 characteristic, delicate, erect pubescence, the joints distinct ; no pulvilli. Face very little 

 projecting, only slightly convex ; proboscis withdrawn ; third an tennal joint short-conical, 

 with a styliform prolongation, the latter gently, but distinctly, tapering from the base to 

 the tip, and in this respect different from the linear style of Lepidanthrax ; the separation 

 of the eyes on the vertex comparatively narrow, distinctly narrower in the male than in 

 the female. The wings of the known species are hyaline, sometimes the costal cell only 

 is darker ; the venation is like that of Anthrax sensu stricto. A peculiarity of those 

 species having the front tibiae beset with spinules consists in the unusual development of 

 the patagia-like organs at the base of the wings, these organs being usually clothed with 

 a dense covering of scales and often with a brilliant silvery or golden reflection ; similar 

 scales, in such cases, adorn the enlargement of the base of the costa ; the prse-alar hook 



