Vol. XI] 



COLE— PRIBILOF ISLANDS DIPTERA 



175 



1, la. Pterallastes borealis Cole, new species. 



2, 2a. Dryomyza hannai Cole, new species. 



3, Acidia uncinata Coquillett. 



4, 4a. Parydra metallica Cole, new species. 



sternopleura with 4 bristles, quite distinct from the surrounding 

 pile. 



Several specimens were taken with the types, most of them 



males. The shape of the head is not exactly typical of Dryomyza, 

 and there are some other characters which make its position in 

 that genus a little doubtful. 



This species is named for Dr. G. Dallas Hanna in recognition 

 of his interest in the insect fauna of the Pribilof Islands. 



Holotype, male, No. 810, and allotype, female, No. 811, Mus. 

 Calif. Acad. Sci. ; collected by G. Dallas Hanna, August 20, 1920. 



Type locality, St. Paul Island, Alaska. 



TRYPETID^ 

 28. Acidia uncinata Coq. 



Several specimens of both sexes were taken on St. Paul Island, 

 August 10 and 12. Coquillett described the species from a 



