288 S. W. WILLISTON. 



Antennse in structure like those of C. cruciatus, the style somewhat shorter; 

 hlaek, the first joint bushy black hairy, the second joint less so. Face projecting 

 a little more below than in C. cruciatus; densely light golden yellow pollinose, 

 and with long, soft, rather abundant light yellow pile below, extending up more 

 thinly in the middle ; occiput below with silky white hair ; above, the occipito- 

 orbital hairs are black, longer and more abundant than in C. cruciatus ; front 

 shining black, with black hair, except some yellowish ones on the ocelligerous 

 tubercle, the orbits narrowly golden pollinose. Dorsum of thorax thickly golden 

 pollinose, leaving two not very broad, median, brownish black stripes, separated 

 by a line, and on each side two large, oval, black spots narrowly separated by a 

 sutural line ; pile or hair rather long and erect, on the front part yellowish white, 

 broadly behind black, the bristly hairs of the post-alar callosities and the scutel- 

 luni light yellow ; pleurae thickly light yellow pollinose, below and on the coxse 

 more grayish. Abdomen in shape like that of C. cruciatus, with short, but abun- 

 dant, erect light yellow pile ; each segment with an opaque, light golden yellow 

 posterior cross band, composed of dense pollen, moderately narrowed on the 

 sides ; that on the first segment narrowest, that on the second comprising about 

 oue-half the segment, on the last leaving only a slender anterior black band. 

 Legs pitchy black, the tibiae and tarsi fulvous pubescent; pile of the coxse, espe- 

 cially the front ones, and of the femora below, long and silky white. Wings 

 nearly pure hyaline ; neuration as in C. cruciatus. 



One specimen, Georgia. The thorax and abdomen in shajje and 

 markings are singularly like those of Laparas pictitarsis Bigot. The 

 '' pedes flavr prevents the identification with the long-lost C. auru- 

 lentus Fabr. 



Iflyelaplilis lobicornis O. Sacken. Western Dipt. 287 ; Williston, Tians. 

 Am. Eut. Soc. xi, 7 ; xii, 53. 



Either there is a number of closely allied species, or else a con- 

 siderable variation in the one. The fourth posterior cell is in some 

 cases wide open, in others narrowed, while in yet others it may be 

 closed and petiolate. I have seen a specimen ( % ) from California 

 in which the abdomen is wholly black, the femora at the base blackish 

 and the tip of the tibise and all the tarsi black. The fourth poste- 

 rior cell is closed in the margin ; otherwise, the specimen is quite like 

 the one I first described. 



myelaphus rufus Williston, Trans. Am. Ent. Soc. xi, 7. 



I have seen a male of this species in which the wings, as I sus- 

 pected, are wholly blackish, except the very base. The fourth poste- 

 rior cell is closed in the margin and the second joint of the antennae 

 is reddish. 

 Dioctria pusio O. Sacken, Western Dipt. 288. 



A male specimen from Colorado I refer to this species. The coxae 

 are yellow, the tip of the hind tibise considerably incrassated and the 



