AMERICAN DIPTERA. 277 



Cyrtopogon dasyllis (PI. IX, fig. 7.) 



Cyrtopogon dasyllis Williston, Kans. Univ. Quart., II, 66, 1893. 

 " % . — Length 16-18 mm. — Black, thickly pilose; pile of face wholly 

 black. Abdomen, except the tip, with long, dense, erect, yellow pile. 

 Tarsi red. Wings hyaline; just before the tip a large, deep brown 

 spot. Face and front with long and dense deep black pile; beard 

 black. First two segments of the antennas black, the third red; style 

 short and thick. Thorax black, thickly black pilose; dorsum deep 

 opaque brown, on the sides narrowly, and behind polished. Scutellum 

 thickly black pilose, subpolished, convex. Abdomen nearly parallel 

 on the sides, polished, but its shape and color largely concealed by the 

 long, erect, yellow pile; the first segment sparingly black pilose on the 

 sides; the last three segments and the hypopygium with abundant 

 black pile. Legs black, black pilose, the coxas with some whitish pile; 

 the tarsi red, the hind tibias more deeply so. Wings hyaline, with a 

 large black or deep brown spot before the apex, extending across the 

 wing; a narrow cloud along the last section of the fifth vein." 



Type. — University of Kansas. 



Habitat. — Colorado, top of Deer Mt. (August, F. H. Snow). 



A male specimen marked "type," loaned me by Prof. F. H. 

 Snow, agrees perfectly with the above description except that 

 all the tibia? are reddish. This species is strikingly like 

 dasylloides but differs, according to Dr. Williston, in the color 

 of the third antennal segment, the facial pile, and in the wing 

 markings. Dr. Williston's species are both founded upon 

 male specimens; dasylloides upon a single male. I have three 

 female specimens which I cannot place with certainty either 

 under dasyllis or dasylloides, and yet they are, beyond doubt, 

 one or the other. Two of them, from Pike, N. Y. (N. Y. St. 

 Mus.), and Sisco, Cal. (Massachusetts Agricultural College), 

 respectively, are like dasyllis except that the antennae are 

 black, the facial pile and beard light golden, as in dasylloides , 

 instead of black, and the wings do not have the distinct spot 

 as found in dasyllis, but have more the coloration of those of 

 dasylloides. The female of dasyllis would not be expected to 

 have a distinct spot on the wing if we can draw any conclu- 

 sions from the male and female wing of bimacula. The third 

 female is from Colorado (Am. Ent. Soc.) ; it has the antennas 

 as in dasyllis, but the pile of the face, beard and abdomen 

 is wholly light yellow, and the wing coloration is more nearly 



TRANS. AM. ENT. SOC., XXXV. • JULY, 1909 



