Vol. XI] CURRAN— REVISION OF THE PIPIZA GROUP 377 



on the broad median lateral margins of each segment. Legs black; tips of 

 femora, basal quarter of hind and half of front four tibiae, tips of all the tibise 

 and the tarsi, yellow; tarsi with last two or three joints darker; pile of legs 

 black or brownish black; hind femora gradually broadened to near the end 

 where they are somewhat suddenly constricted to about three-fourths their 

 greatest width. Wings cinereous hyaline; stigma luteous. 



Female: Not at all similar to the male. Face and front shining black; 

 face lightly dusted with whitish pollen; front with a rather large triangular 

 dusted spot on each orbit below the middle; pile white, black immediately 

 above the base of the antennae; across front before ocelli brownish black pilose. 

 Antennae black, tip of second and whole of third joint brownish; arista yellow 

 at base. Eyes very short white pilose; post-orbital pile and occipital cilia 

 entirely white. Thorax and scutellum with short white pile. Abdomen 

 shining black, second segment with an arcuate, broadly interrupted, yellowish 

 red cross-band, often resembling two large sub-quadrate yellow spots, the 

 outer ends usually more rounded in front. These spots do not vary much and 

 are about 1 J^ times as long as wide. Pile of abdomen short, white, except the 

 usual areas where the pile is very short and black. Legs as in male except 

 that the pile is shorter and white. Wings as in male. 



Numerous specimens of both sexes from various parts 

 of Ontario. The male cannot well be confused with any 

 other species, but the female is easily confused with 

 femoralis but can be readily distinguished by the ab- 

 sence of the spinose area on hind femora. There can 

 be no question about this female belonging here. 

 Pipiza femoralis is common in Ontario and the hind 

 femora in both sexes bear spinose hairs. 



40. Pipiza davidsoni, new species (Figs. 104, 108) 

 Habitat: California! Rather robust; metallic black- 

 ish, the thorax metallic bluish black; hind femora very 

 slender. 



Length, 7.5 to 9 mm. Male: Face and frons shining metallic bluish black; 

 thinly covered with whitish pollen which leaves a very narrow median facial 

 stripe extending onto the front, bare and shining; pile rather long, black; on 

 the face appearing lighter colored, sometimes white on cheeks; vertical triangle 

 with lighter pile behind. Antennae black; third joint obscurely reddish, in 

 shape sub-cordate, scarcely longer than broad; second joint sometimes luteous 

 apically. Eyes with brownish or tawny pile above, more whitish below; post 

 orbital pile and cilia blackish. Antennal process less produced and less conical 

 than usual. Thorax and scutellum shining metallic bluish; finely and sparsely 

 long white pilose, on the humeri slightly grayish pilose; on apical portion of 

 scutellum with long black hairs intermixed; scutellum without a groove. 

 Abdomen shining metallic black, the usual areas opaque; pile moderately 

 long, light colored, the usual areas reaching sides, with black pile; hypopygium 

 entirely black pilose; basal portion of sexual organ broader than long. Legs 

 black, white pilose; tips of all femora, narrow base of hind, base of front four 

 tibiae and their tips and tarsi, luteous reddish; hind basitarsi and apical joints 

 of all tarsi darker; hind femora very slender, not spinose. Wings hyaline; 

 stigma^luteous; halteres blackish. 



Holotype, male, Walnut Creek, California, no date 



December 31, 1921 



