350 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. 



occipital cilia black face very gently convex in middle, its sides narrowly and 

 two minute spots above middle of frons at orbits, white pollinose. Antennae 

 luteous, third joint above and apically brownish, about four times as long as 

 wide; arista bare, its basal half luteous; eyes short black pilose, broadly bare 

 across the middle. Thorax and scutellum shining black, slightly greenish; 

 pile short, sparse, white; scutellum without apical groove. Abdomen shining 

 black, the sides with a metallic bluish reflection; pile short, white; the broad 

 posterior margins, not reaching the sides, of the second and third segments 

 with black pile, fourth segment with cinereous pile on basal third. Legs black, 

 tips of front four and narrow base of hind femora, base of front, basal half and 

 extreme tip of middle tibiae; first two joints of anterior four and middle two of 

 hind tarsi, and tip of hind basitarsi, yellow; hind basitarsi slightly incrassate. 

 Wings tinged with brownish, not clouded; last section of fourth vein sub- 

 angulated immediately before its middle; of fifth, rectangular; halteres yellow. 



From P. pulchella Williston, it differs in having basal 

 antennal joints yellow, black pile on the front, black 

 occipital cilia, and slightly brownish wings; other dif- 

 ferences in color are also noteworthy. The wings are 

 too light for P. australis. 



The specimen is interesting as occurring practically 

 between the range of P. pulchella and P. australis. It 

 may be either a southern form of pulchella or a northern 

 form of australis, or it may prove to be a good species, 

 but without specimens of pulchella I refrain from giving 

 it specific rank. 



Holotype, female, from Mr. W. M. Davidson, labelled 

 "Falls Church, Va. (N. Banks), Ceanothus (N. J. Tea), 

 June 14," in U. S. National Museum. 



4. Pipizella occidentalis (Townsend) 



Pipiza occidentalis Townsend, Ann. Mag. Nat. Hist., 

 6th ser., xix, 140, 1897. 



Habitat: New Mexico (Towns.) One female, Rio 

 Ruidosa, four miles west of Dowling's Mill, 6660 ft., on 

 flowers of Rhus glabra L., July 10. (Wooton.) 



"Length, 5 mm. Differs from Williston's description of P. pulchella only 

 in the following particulars: Abdomen less than twice as long as the thorax; 

 no slender deep groove before the margin of the scutellum; legs black, tips of 

 all the femora, bases of anterior tibiae, basal two joints of the front and middle 

 tarsi and tips of the hind basitarsi with the next joint, yellowish or reddish 

 yellow; hind basitarsi not more swollen than the other joints; apical cross- 

 vein sub-sinuate, abruptly straight at its base but curved on its final portion 

 forming a right angle with the fourth vein; auxiliary vein terminating hardly 

 beyond the anterior cross-vein. Closely like pulchella in all other points. 

 This species is very distinct from the two described by Williston in the Biologia 

 Centr. Am., Dipt., iii, pp. 6-7." (Townsend.) 



