6 COQUILLETT [39 2 ] 



vein ; third joint of antennae twice as long as wide, hypopygium of 

 male at least one-half longer than the longest segment of the abdomen 

 preceding it. Length 4.5 mm. A specimen of each sex, taken June 

 21 and :;. 



Habitat. Yakutat and Orca, Alaska. 



/Y/V. Cat. no. 5192, U. S. National Museum. 



Readily recognized among the black forms by the unspotted wings, 

 which have no indication of an auxiliary crossvein. 



Sciara abbreviata Walker. 



Sciara abbrf-nadi WALKER, List Dipt. Ins. British Museum, i, p. 109, 1848. 

 Popof Island, Alaska: Three females, collected June 12, 14, and 

 1 6. Originally described from Hudson Bay, British America. 



Sciara groenlandica Holmgren. 



Sciara grccn/andica HOLMGREN, Ofversigt Vet.-Akad. Fbrhand., p. 104, 

 1872. 



Popof Island, Alaska: Three females, collected July 10. Hereto- 

 fore reported only from Greenland. 



Sciara iridipennis Zetterstedt. 



Sciara iridipennis ZETTERSTEDT, Insecta Lapp., p. 827, 1840. 



Popof Island, July 12 and 15; Muir Inlet, Alaska, June 12: Eight 

 specimens. Originally described from Lappland, and also reported 

 from Greenland. 



Sciara borealis Riibsaamen. 



Sciara borealis RUBSAAMEN, Bibliotheca Zool., p. 109, 1898. 



Sitka, Alaska : Two specimens, collected June 16. Originally de- 

 scribed from Greenland. 



Sciara tridentata Riibsaamen. 



Sciara trident ata RCnSAAMEN, Bibliotheca Zool., p. 107, 1898. 



Lowe Inlet, British Columbia: A single specimen, collected June 3. 

 It was originally described from Greenland. 



Sciara expolita sp. nov. 



Head black, mouth parts and antenna? blackish brown, third joint of 

 antennae almost twice as long as broad, the eighth joint the same, its 

 upper and lower edges parallel ; thorax black, mesonotum highly 

 polished, humeri pale yellow, prolonged as a triangular spot on the 

 pleura; scutellum and metanotum black, the latter highly polished; 

 abdomen pale yellow, the sides, hind margin of the segments, also the 

 apical portion of the abdomen beyond the sixth segment, black, the 

 end lamella slightly longer than broad ; coxae and femora pale yellow, 



