I8S2.] '^-'^ [Williston. 



agree so closely with Loew's description that I believe them to he the 

 same. 



Xylota ejuncida Say. Com pi. Wr. 1, 15 ; PI. 8, fig. 4. Wash. Terr., 

 Calif. ! New England. Numerous specimens from these localities re- 

 semble so closely the Eastern ones, that I scarcely doubt their identity. 

 The third joint of the tarsi varies from yellowish to quite black, and the 

 spine or tubercle of the hind coxae is quite distinct ; the antennae vary 

 somewhat is color. Is X quadrimaculata Lw. really a distinct species ? 

 Observe the discrepancy between the diagnosis and description as regards 

 the male coxae. 



Xylota PiGRA (Fab.) Meigen. Oregon, Wash. Terr., Calif. ! Europe 

 and North America. Common. 



Xylota, sp. nov. Colorado. 



Differs from 8. bicolor Lw. in the presence of long coxal spines ; in all 

 the tarsi except the last two joints, the anterior and middle tibiae, and the 

 posterior tibiae at base and tips being yellowish-red. 



hh. — Face descending more or less below the eyes, often obtusely tubercu- 

 late. Thorax either with distinct spots or abdomen banded. 

 k. — The sixth vein beyond the junction of the posterior basal cross- 

 vein, extends forwards subparallel to the border, the discal cell 

 rounded on its posterior angle, hind femora swollen (and with a 

 triangular protuberance below on outer part ; anterior part of 

 wings more or less clouded). 

 1. — Second joint of antennae, elongate ; antennae about as long as 

 head Mixtemyia. 



11. — Second joint of antennsfi not elongated, the antennae shorter than 

 head Spilomyia. 



Spilomyia interrupta, sp. nov. 



(^ 9 • — Very closely allied to 8. longicornis, but seems to show a constant 

 difference in that the first, third and fifth cross-bands are distinctly though 

 narrowly interrupted, and that the last section of the sixth longitudinal 

 vein is distinctly shorter, scarcely more than half as long as the posterior 

 basal cross- vein. The posterior side of the hind femora are in some speci- 

 mens quite black. Washington Territory. 



The generic differences between our species of Mixtemyia and Spilo- 

 myia are very trivial. 



kk. — The last section of the sixth vein short, running directly into the 



border of the wing, hind femora not swollen, nor with spines or pro- 



jection below. 



m. — AntennsB inserted high up on a conical projection, front very 



short, face much produced directly downwards, obtusely tubercu- 



late, antennae shorter or longer than the head Sphecomyia. 



Sphecomyia vittata (Wied.) O. S., Wied. Aus. Zwei., ii, 87, and 91 

 (Psarus ornatus). Eastern States ! Colorado. 

 *Sphecomyia brevicornis O. S., West. Dipt., 341. California. 



