26 Journal of EntoiTiolojj;\' and Zoology 



Female. In general very much like the male but lighter in 

 coloration. Pile of cheeks and lower occiput yellowish, on the rest 

 of the head and on the antennae reddish brown. Eyes widely 

 separated, the pollen of frons more buff colored than in male, the 

 pile shorter. Pollen of mesonotum much lighter in color than in 

 male, the pile shorter and paler. Ground color of coxae and pleura 

 yellowish brown in some specimens, the pile yellow. Knob of 

 halteres scarcely darkened below. Abdomen in dried specimens 

 yellow, also the tibiae except apices and bases of the four front 

 tarsi. Pile and fine setulae of femora and tibiae yellowish. 



Holotype, a male, and allotype, a female, collected on the sand 

 dunes near Golden Gate Park, San Francisco, Cal., September 10. 

 1920 (F. R. Cole), in the collection of the California Academy of 

 Sciences. 



Paratypes. — Two specimens in the Cal. Acad, of Sci., taken in 

 the type locality, and five specimens in the writer's collection, taken 

 with the typ^s. 



In 1895 Coquillett described Acreotrichus americanus from a 

 single male specimen taken in the state of Washington. This litt'o 

 species has hyaline wings, the antennae are quite different and the 

 proboscis comparatively longer. In May, 1917, the writer too^: 

 a single male specimen of A. americanus near Hood River, Ore- 

 gon ; it appears to be a rare species. A. atratus Coquillett, from 

 Mexico, has a slender third antennal joint, three times as long as 

 the first two combined and of nearly an equal width; the wing; 

 are grayish hyaline. The three other known species in the genus 

 are described from Australia. 



