HELEOMYZID FLIES NORTH OF MEXICO—GILL 045 
FrMALE.—Similar to male, except for terminalia. 
Lreneru.—4.5-6.5 mm. 
Disrrisution.—Washington, Oregon; May, July, August, October. 
Biotocy.—All specimens examined were collected along the coastal 
areas of the states mentioned. The habits of this species are probably 
similar to A. maculatum Darlington (see below). 
Anorostoma maculatum Darlington 
Fiaure 41 
Anorostoma maculata Darlington, in Aldrich and Darlington, 1908, p. 76. 
Anorostoma maculatum Darlington, Czerny, 1924, p. 115.—Curran, 1933, p. 3. 
Ma.e.—Front orange; vertex and upper part of back of head dark 
gray with a silvery pollinosity; antennae black, except for white ring in 
proximal half of the aristae; a black spot covers the area between the 
antenna and the eye; remainder of head pale yellow with a silvery 
pollinosity; vibrissae short, about as long as the third antennal 
segment; eye horizontally oval, the cheek-eye ratio about 0.9. 
Thorax blackish or brownish in ground color, with a silvery gray 
pollinosity; chaetotaxy and coloration very similar to A. cinereum 
Curran. 
Legs yellow, with femora darkened and with a silvery pollinosity. 
Wings with contrasting whitish and grayish areas; marginal cell 
(cell R,) is grayish except for the distal part, which is distinctly 
whitish. (In A. cinereum Curran this cell is practically all whitish, 
whereas in A. opacum Coquillett it is entirely darkened.) 
Abdomen black, with a silvery pollinosity; postabdomen pale 
yellow. 
FrmMaLe.—sSimilar to male except for terminalia and femora, the 
latter not as greatly thickened as in the male. 
Lrenetu.—4.0—-4.5 mm. 
DistriputTion.—California; April-August. 
Remarks.—It was noted in the original description that these flies 
are common in sand-dune areas, where they fly close to the sand and so 
resemble grains of drifting sand. It was further noted that when the 
flies alight, their mottled color blends perfectly with the sand. 
I have examined 15 syntypes (No. 11980) of this species in the 
U.S. National Museum. 
Anorostoma opacum Coquillett 
Anorostoma opaca Coquillett, 1901, p. 614.—Aldrich and Darlington, 1908, p. 76. 
Anorostoma opacum Coquillett, Czerny, 1924, p. 114.—Curran, 1933, p. 3. 
I have examined the type (No. 5500), a female, in the U.S. National 
Museum. It resembles A. maculatum Darlington very closely, except 
