AMERICAN DIPTERA. 247 



SYNOPSIS OF SPECIES. 

 Facial gibbosity more even below, rather suddenly constricted 



above; body with abundance of erect pile simplex. 



Facial gibbosity greatest in the middle and gradually receding 

 above and below, less pilose species. 



sparsipilosum n. sp. 



Dicolonus simplex. 



Dicolonus simplex Loew, Cent., VII, 56, 1866. 

 Dicolonus simplex Williston, Trans. Am. Ent. Soc, XI, II, 1884, 

 pi. I, fig. 4. 



<$ 2. — Length 10-11 mm. — Wholly polished black, clothed with 

 rather dense furry light yellow pile, but this nowhere fully concealing 

 the ground color. 



Head wholly yellowish pilose except that on the palpi, on the outer 

 edge of facial tubercle, on the antennal tubercle, first segments of 

 antennae, front and narrowly on the occipital orbits, where it is black; 

 that on the antennal tubercle sometimes yellowish. Facial tubercle 

 on the lower portion of face rather even, more suddenly constricted 

 above. Extreme tip of abdomen usually with some black pile inter- 

 mixed with the yellow. Legs wholly black, thickly clothed with the 

 same yellowish pile and weak bristles as the body; claws black, very 

 narrowly reddish at the base. Wings grayish; the second basal, anal, 

 and axiliary cells except distally, and the discal cell, appear milky- 

 white when viewed on about the same level from behind or when over 

 a dark surface. 



Type. — M. C. Z. A single female. 



Habitat.— Col.; Los Angeles Co., Cal. (D. W. Coquillett). 

 There are several specimens of this species at the National 

 Museum. 



Dicolonus sparsipilosum n. sp. (PI. IX, fig. 2.) 



cj\ — Length 7 mm. — Wholly polished black with bluish reflections; 

 to the unaided eye nearly bare, not clothed prominently with furry, 

 erect pile. 



This species is very closely related to the Californian simplex, but 

 differs noticeably in the scarcity of the pile. The pile and exceedingly 

 weak bristles are throughout yellowish, as in simplex, but the pile is 

 very short and has a tendency to be appressed, while in simplex it is 

 longer, furry and erect. The pile of the facial gibbosity is less in extent 

 and without any black; the gibbosity itself is decidedly greatest in 

 the middle and gently rounds off to the face above and below; in 

 simplex it is more even and more suddenly constricted above. Like 

 simplex, the pile of the antennal tubercle, basal segments of antennae 

 and front is black. Pile of palpi black and yellow mixed, and the 



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



