118 DIPTERA. 



A. alcyon, v. d. Wulp, Tijdschr. voor Ent. xxv. t. 9, f. 1, from Arizona is, I suspect, 

 my A. pcecilogaster. 



4. Anthrax pcecilogaster, sp. n.,d ? . (Tab. II. fig. 12.) 



Head yellowish, almost wax-colour, with an appressed, golden pubescence, and black, erect hairs; vertex black, 

 the upper part of the occiput greyish, beset with pale orichalceous appressed hair ; basal joints of the antennae 

 reddish, the third joint black. Thorax greyish-brown, with an appressed fulvous pubescence forming a pair 

 of indistinct stripes in the middle, and longer, erect fulvous hairs in front and on the sides (when the pube- 

 scence of the thoracic dorsum is abraded and the surface is not greasy, two darker stripes are visible on 

 the greyish-brown ground-colour). Scutellum reddish, black at the base. First segment of the abdomen 

 black, the others rufous, with a transverse black spot in the middle of each, beginning with the second 

 (these spots are visible in abraded specimens only) ; the hairy covering of the abdomen consists of a partly 

 rufous, partly yellowish-white tomentum, the latter predominating on the sides and on the anterior 

 portion of the second segment ; in well-preserved specimens, in the middle of each of the segments 2, 3, 4, 

 there is a short, tuft-like cross-band of black hairs, broadly interrupted in the middle, the interruption 

 being filled with a whitish tomentum ; tufts of black hairs along the sides of the abdomen, beginning with 

 the second segment; legs rufous, the tips of the tarsi darker. Knob of the halteres whitish. Wings on 

 the pattern of A. alcyon, Say, but narrower ; a stump of a vein within the third posterior cell ; a hyaline 

 spot close by the axillary incision across the middle of the axillary cell, sometimes reaching across the 

 anal cell also ; the ends of the second and of the upper branch of the third vein thickly clouded with 

 brown ; the hyaline space within the discal cell rather large and in contact with the anterior branch 

 of the fourth vein ; the hyaline space connecting this spot with the posterior margin rather clear, the 

 intercalary vein crossing it being alone a little clouded ; the hyaline spot at the distal end of the second 

 basal cell very distinct ; the brown colour not very dark and variegated with yellowish and rufous. 



Length 11-12 millim. 



Bah. Noeth Amekica, California. — Mexico, Northern Sonora (Morrison), Tehuacan 

 (coll. Bellardi). Seven specimens. 



A. pcecilogaster differs from A. arethusa as follows: — 1, the third posterior cell is 

 not bisected, but contains a stump of a vein ; 2, the black tufts on the sides of the 

 abdomen are very distinct on the second, as well as on the following segments; 3, the 

 hyaline spot in the distal half of the second basal cell, near the proximal end of the 

 discal, is not obsolete, but on the contrary very distinct ; 4, there is a more or less 

 distinct hyaline spot across the axillary cell, close to the axillary incision, and reaching 

 sometimes into the second basal cell ; 5, well-preserved specimens show, on segments 

 2, 3, 4 of the abdomen, short, tuft-like, interrupted cross-bands of dark hairs, easily 

 abraded. I notice also that in all my specimens the ends of the second vein and of the 

 anterior branch of the third are distinctly diverging, while they are more or less 

 parallel in A. arethusa. 



I have five specimens from Shasta district, California (Edwards), which somewhat 

 resemble A. pcecilogaster, but are, on the average, a little larger and broader ; the 

 wings are less variegated, more uniformly brown ; there is no subhyaline space in the 

 axillary cell, the hyaline spots in the third and fourth posterior cells are smaller ; the 

 tomentum on the abdomen is principally yellow, and not mixed with whitish. The 



