AMERICAN DIPTERA. 333 



geminate stripe on the dorsum which are rich velvety brown. Ab- 

 domen reddish-yellow; the tergum where not covered with whitish 

 bloom, a rich reddish-brown. Wings hyaline; submarginal and pos- 

 terior cells open; the fourth posterior at base petiolate in varying 

 degree. 



Antennae normal, black, covered with whitish bloom. Mystax com- 

 posed of white bristles confined to the oral margin; front with notice- 

 able pile; occipital bristles white; as in trifasciatus, forming a row 

 behind the vertex; beard white and very scanty. The median gem- 

 inate stripe of thoracic dorsum narrowly divided by a fine line of white 

 bloom; abbreviated anteriorly but posteriorly the two portions sep- 

 arate and becoming more narrow, extend to the scutellum. Micro- 

 scopic hair of dorsum black, leaving the same two bare areas behind 

 the transverse suture as in trifasciatus; two well developed bristles 

 on each side, one presutural, the other on the posterior callosity. 

 Pleuras without noticeable pile; trichostical bristles white. Scutellum 

 white pruinose; without long bristles or pile. Halteres white. Ab- 

 domen a rich reddish-brown above; the anterior and posterior margins 

 of segments 1-4 narrowly white pruinose, the anterior margins of the 

 segments 3-4 much more prominently so; tip of abdomen, venter and 

 the sides of segments 1-4, broadly, of the remaining segments, slightl5^ 

 whitish pruinose; tergum with microscopic black and white pile; the 

 bristles on the sides of segment 1 white. Legs black, wholly, but not 

 densely, white pruinose; the trochanters, tibiae and tarsi for the most 

 part reddish; claws black, reddish at base; pul villi sordid. 



The female differs from the male in that the tergum of the abdomen 

 is darker and all the segments of the abdomen broadly whitish pruinose 

 on the sides, this bloom extending narrowly upward onto the anterior 

 border of each segment. 



Type. — -Type series consists of three males and one female, 

 all of which are at the American Museum, except one male 

 co-type, which is in the collection of the Massachusetts Agri- 

 cultural College. 



Habitat.— Goth^, Fla. (March, 1896, W. M. Wheeler) ; Winter 

 Park and Orlando, Fla. (April-July, E. A. Back). 



This is somewhat smaller species than trifasciatus and can 

 be easily separated from it by the coloration of the abdomen 

 and the anteriorly dilated geminate thoracic stripe. It more 

 nearly agrees with the variety of trifasciatus mentioned from 

 lower California and Kansas, but is distinct. It is very com- 

 mon in the vicinity of Orlando, Florida, during the last of 

 April and in May, June and July, frequenting sandy spots, 

 especially in and about gardens. 



TRANS. AM. ENT. SOC, XXXV. AUGUST, 1909 



