ANTHEAX. 133 



the tarsi darker ; pul villi indistinct. Wings hyaline, except the antero-proximal third and a spot at the distal 

 end of the marginal cell, which are black ; the boundary of the black starts near the axillary excision, 

 crosses obliquely the anal cell near its middle (so as to strike the cross-vein at the distal end of the second 

 basal cell), cuts off a small corner of the discal cell (which thus remains hyaline, except that little spot), 

 crosses the first posterior and first submarginal cells a short distance beyond their proximal ends, follows 

 for a short distance the second vein, crosses the marginal cell, and follows the first vein to its very end. 

 The black spot is immediately at the tip of the first vein, and fills out a part of the expanded end of the 

 marginal cell ; a much smaller spot, in contact with the large one, is placed on the costal margin, between 

 the ends of the second and of the anterior branch of the third vein. 

 Length 9-10 millim., and smaller specimens down to 5 millim. 



Eab. Mexico, Northern Sonora (Morrison). 

 I have seven specimens, apparently all males. 



24. Anthrax sinuosa. 



Anthrax sinuosa, Wiedem. Aussereur. zweifl. Ins. i. p. 301 ; O. Sack. Western Diptera, p. 239 (for 

 the synonymy see my Catal. N.-Am. Dipt. 1878). 



Eab. United States. — Mexico, Northern Sonora (Morrison). 



I have a single worn specimen from Sonora before me which may be referred to this 

 species ; I have compared it with several similarly rubbed-off specimens from Texas. This 

 species is most remarkably like Isopenthes jaennickeana ; and if the cross-vein bisecting 

 the submarginal cell in the latter were wanting, it would not be easy to distinguish them. 

 Even the peculiar sericeous appearance of the surface of the wings, so much apparent in 

 I. jaennickeana, exists, although in a lesser degree, in A. sinuosa. I regret not having 

 intact specimens of the latter for a closer comparison ; all I can notice at present is 

 that the first posterior cell in I. jaennickeana is more coarctate towards the end and 

 more expanded about the middle ; that the clear spots on the cross-veins within the 

 brown are less clear in the latter species ; and that in the fourth posterior cell nearly 

 the whole distal half is hyaline, while in A. sinuosa it is only the distal end. The 

 small pulvilli are quite distinct in both species. 



25. Anthrax ?, tf. 



Eab. Mexico, Northern Sonora (Morrison). 



I have a single male specimen which is very like A. sinuosa, but certainly distinct : 

 it is 7-8 millim. long, has the black ground-colour very little hidden by pale yellowish 

 pile, and the sides of the segments, beginning with the end of the second, with tufts of 

 black hair. The brown on the wings is not unlike that of A. sinuosa, but less dark ; the 

 clear margins on the cross- veins and bifurcations are, on the contrary, more distinct ; the 

 hyaline along the posterior margin is broader, as it occupies at least one half of the 

 fourth posterior cell and more than half of the first posterior and first submarginal 

 cells ; the bifurcation of the third vein is some distance from the boundary of the 

 black, while in A. sinuosa it is close upon it; finally, the small brown spot on the 



