Vol. XI] ALEXANDER— PRIBILOF ISLANDS DIPTERA 183 



DIPTEROUS INSECTS OF THE FAMILY TIPULIDiE 

 FROM THE PRIBILOF ISLANDS, ALASKA 



BY 

 C. P. ALEXANDER 



University of Illinois 



The collection of Tipulidse secured by Dr. G. Dallas Hanna 

 on the Pribilof Islands, Alaska, in 1920, contains five species. 

 One of these is a very remarkable insect which is believed to be 

 a new species and is made the type of a new subgenus. The 

 description of one other species has recently been published by 

 the writer. The remaining- three species were first discovered 

 by Messrs. Hanna and Whitney on the Pribilof Islands in 1912 

 to 1914. Descriptions of these were drawn up for publication by 

 the U. S. Biological Survey several years ago, but unfortunately, 

 their appearance has been delayed. In order to save confusion 

 for future bibliographers it does not seem to be advisable to give 

 publicity to the three names prior to their appearance with 

 descriptions. 



1. Tricyphona glacialis Alexander 



Can. Ent. vol. 49,1917 



Two males, St. Paul Island, June 19, 1920. 



Nesotipula Alexander, new subgenus 



Characters as in Tipula, s. s. ; wings with but two branches 

 of media attaining the margin; radial sector elongate; m-cu at 

 or before the fork of M. 



Type of the subgenus, Tipula (Nesotipula) pribilovia, new 

 species. 



2. Tipula (Nesotipula) pribilovia Alexander, new species 



General coloration black ; wings semiatrophied ; Rs long ; two 

 branches of M reach the wing-margin; m-cu at or before the 

 fork of M. 



