170 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. 



2. Boletina sp. 



One male of an undescribed species, St. Paul Island, June 

 21. Too poorly preserved for description. 



3. Neosciara sp. 

 Near tridentata Rubs. One female in rather poor condition, 

 so that its identity is not certain, St. Paul Island, June 21. 



DOLICHOPODID^ 

 4. Hydrophorus fumipennis Van Duzee 



For description see page 167 of preceding paper. 



5. Dolichopus rupestris Halid. 

 St. Paul Island, August 10. Previously described from St. 

 Paul Island and from Kukak Bay and Popof Island, Alaska. 



empid;e 



6. Empis sp. 



One male of a species probably undescribed, St. George 

 Island, June 30. In poor condition. 



7. Rhamphomyia sp. 

 One female of a species very close to conservatica Malloch, 

 recently described from the Yukon and Northwest Territory. 

 St. Paul Island, August 10. 



SYRPHID^ 

 8. Pterallastes borealis Cole, new species, figures 1, la 



Female: Length 13.5 mm. Very near P. periidiosus Hunter. 



Antennae black, arista brown and bare, third joint about as 

 broad as long (fig. la). Middle of face and triangle in front 

 of cheeks shining black (fig. 1), otherwise yellowish pollinose 

 and pilose, with yellowish ground color under the pollen. Vertex 

 black ; frons yellowish pollinose, with erect black pile. Occiput 

 yellowish gray with yellow pile and a few black hairs above eye 

 margin. Proboscis black. 



Mesonotum opaque black, with yellowish pollen on lateral 

 margins and two faint yellow longitudinal stripes, widely sepa- 

 rated and narrow ; pile rather dark yellow. Narrow base of 



