ANTHEAX. 139 



N.B.— There is another A. stenozona, Loew, Beschr. eur. Dipt, i. p. 180, from Asia 

 Minor, likewise a Hyalanthrax. Both were published in 1869, but the American species 

 has priority. 



32. Anthrax livia, sp. n., <$ $ . (Tab. ill. fig. 2, <? .) 



Ground-colour black, clothed with pale-yellow hairs and tomentum ; the hairs form a covering on segments 

 1-4, which is more dense in the male than in the female ; in both sexes, however, this covering is not 

 dense enough to render less conspicuous the cross-bands formed by the tomentum (different in this from 

 A. ayrippina, where the hairs are much longer and more dense); these cross-bands occupy the anterior 

 portion of segments 2, 3, 4, and are broader on the sides than in the middle (that on segment 3 is narrower 

 than the others, that on segment 4 the broadest, in some unabraded specimens the latter cross-band occupies 

 the whole segment) ; the same segments 2, 3, 4 have a narrow fringe of yellow tomentum along the hind 

 margins, coalescing with the cross-bands on the next segment (these fringes are more distinct in the male 

 than in the female and often abraded); segments 5 and 6 are deep black anteriorly, owing to an appressed 

 tomentum of that colour, and their hind margins have a dense fringe of pale yellow hairs ; segment 7 is 

 beset with pale yellow and white hairs, the white hairs principally on the sides and beneath, and a little 

 more conspicuous in the male than in the female. The venter is densely clothed with a whitish tomentum, 

 except on segments 5, 6, 7, which have more or less distinct black cross-bands, corresponding to the cross- 

 bands of the dorsum ; the cross- band on segment 5 is usually the most distinct. The sides of the abdomen, in 

 correspondence with the colouring of the dorsum and venter, are beset with pale yellow hairs, except the 

 segments 5 and 6, which have small tufts of black hair. Face densely clothed with white, sometimes 

 pale yellowish, hairs ; the lower part of the front with similar hairs, higher up they become more yellow ; 

 the front beset with the usual black, erect pubescence ; occipital orbits with a fringe of white, sometimes 

 silvery, scales. The hairs on the thorax above are pale yellowish, on the underside whiter ; the usual 

 triangle of yellow tomentum in front of the scutellum, and a fringe of similar tomentum on its posterior 

 margin ; unabraded specimens show three stripes of the same sort of tomentum on the thoracic dorsum. 

 Halteres pale yellow. The dark ground-colour of the legs nearly hidden under a dense covering of yellowish 

 and reddish-yellow scales, whiter or whitish on the femora ; the tarsi and the tips of the tibiae black. 

 Wings hyaline, including the costal cell ; the root reddish-yellow ; auxiliary vein, fifth vein, before the 

 great cross-vein, and sometimes also a portion of the first vein, rufous ; the enlargement of the costa has a 

 fringe of black hair, and on the disc yellow or reddish-yellow metallescent scales ; the scales of the patagia 

 are whitish or pale yellowish (seldom reddish), more or less metallescent in an oblique light (there is less 

 difference in this respect between the sexes, and the silvery reflection is less conspicuous here than in 

 A. agrvppina). 



Length 10-14 millim. 



Eab. Mexico, Northern Sonora {Morrison). Six males, five females. 



N.B. — Anthrax mucorea, Loew, Centur. viii. no. 43, from Nebraska, must be very like 

 A. livia, but I am not certain about their identity. 



33. Anthrax agrippina, sp. n., <? $ . (Tab. III. fig. 3, $ .) 



Ground-colour brownish-black, densely clothed with rather long, erect, fulvous hairs, which are especially 

 conspicuous along the sides of the abdomen ; the segments 5 and 6 alone have, on each side, a tuft of 

 black hair. Towards the end of the ahdomen, especially in the male, the long erect hair increases the 

 apparent breadth of the segments and gives them an unusually bushy appearance ; the hairs being planted 

 in dense rows or fringes on the anterior part of the segments, the darker ground-colour of the posterior 

 part is more or less visible between the rows and produces a more or less distinct appearance of dark 

 cross-bands. In the female these black cross-bands are much more distinct, owing to the long, erect, 

 fulvous hairs being less dense, and the segments 2, 3, 4, &c. have, along their anterior margins, distinct 

 cross-bands (attenuate, or even interrupted, in the middle) of yellow tomentum ; the yellow cross-bands 



t2 



