Dec, 1904] Tahanidae. 221 



marginal, with the exception that there may be a trace of hyahne 

 across the second vein, the broad apex of first submarginal, and 

 reaches into the second submarginah The cross-band occupies 

 about half of the first submarginal, first, third and fifth posterior, 

 one-fourth of second posterior, all of discal and fourth posterior 

 and small apical parts of anal, and first and second basal; one- 

 half or more of second basal, all of axillary and anal, except apex 

 of latter are hvaline. Abdomen black and yellow, black as fol- 

 lows: first segment beneath the scutellum, second with two tri- 

 angular spots united on anterior margin of the segment, but not 

 reaching posterior, third and fourth segments each with four 

 spots longitudinally separated by yellow, fifth and following seg- 

 ments except posterior margins. In some cases the fifth segment 

 is colored like the previous one. Venter with a rather wide 

 median stripe and a narrow lateral one. 



Male, S millimeters, some specimens slightly smaller and some 

 slightly larger. Head and its parts differing from those of the 

 female only in sexual characteristics. Thorax not showing 

 stripes as plainly, but otherwise this and the legs are as in the 

 other sex. Wings with a spot in each basal cell equal to about 

 one-fourth the length of its respective cell, and a fuscous patch in 

 the base of the anal cell, otherwise like w4ngs of the female. 

 Abdomen, first segment black with the exception of a small yel- 

 low area on each external lateral margin, second segment yellow 

 on sides and on posterior margin, the black is extended and 

 reaches the anterior margin, but posteriorly is divided by ante- 

 rior projections from the vellow posterior margin, so that it may 

 be said to send backward four projections, the narrow lateral ones 

 of which mav be cut ofi: bv vellow and exist as separate spots, the 

 third and fourth segments are like the second, but the lateral 

 black spurs are not cut off, the fifth segment suggests the one 

 before it, but the yellow is more or less obscure, excepting a nar- 

 row posterior margin, sixth segment black. Venter as in female. 



A number of specimens from different collectors, taken in 

 southern California. The species is named for D. W. Coquillett, 

 who has produced a large number of valuable contributions to 

 Dipterological literature and to entomology in general, and who 

 collected several of the specimens near Los Angeles. 



The species is nearest related to pachycera, but its larger size, 

 difterent abdominal markings and a more extended coloration on 

 the basal part of the second basal and anal cells are distinctive 

 in both sexes. 



Chrysops discallis Williston. This distinct species has some- 

 what the appearance of fulvaster, but does not have the enlarged 

 first antennal segment. It is rather large in size and may be 

 known bv the prominent hvaline spac in the dis cl cell of the 

 wing. 



