4 c Cana .tan Arctic Expedition, 1913-18 , 



-^ From the above material a good idea of the general facies of the crane-fly 

 fauna of the Canadian Arctic Northwest may be obtained. The species are 

 almost, if hot all, forms of dull, sombre colouration — browns or greys — and most 

 of them are of simple, primitive organization. A considerable number show 

 unmistakable signs of degeneracy in the wings, this condition being particularly 

 noticeable in the Pribilof islands, where fully half of the known species have 

 the wings more or less atrophied. In the present collection, two of the Limno- 

 biine forms showed the first stages of wing-atrophy, but all of the ten Tipuline 

 species are full-winged. Some of the species of Arctic Tipulidse have the head, 

 the thoracic intervals, the pleura, coxse, etc., clothed with an abundant long, 

 erect pubescence. Many of the Arctic crane-flies seem to be very local in their 

 distribution. Thus the collections from the Pribilof islands show not one 

 of the species taken elsewhere in the Canadian northwest (with the possible 

 exception of Trichocera) . Similarly, the collections of the Harriman expedition 

 and the present collections show that the species are in large part very local 

 in their distribution, the natural barriers of mountains and large water-bodies 

 having proved a very efficient check upon their dispersal. In the present col- 

 lection there are a total of sixteen spfecies, only two or three of which have been 

 found elsewhere; of these Tipula arctica and Stygeropis parrii are rathqr well- 

 known Arctic American species, and the Trichocera is probably Holarctic in 

 its distribution. 



The collection that is reported upon in this paper is constituted as follows : — 



Rhyphidce — 



Trichocerinw — 



Trichocera 1 species. 



Tipulidoe — 



Limnobiinoe — 



species. 



The general tendencies of distribution of crane-flies in the high Arctic 

 regions are well shown by the above list, the omnipresent Trichocera, a dominance 

 of Pediciine and Tipuline genera, with a smattering of Limnobiini, Eriopterini 

 and Limnophilini. The extensive tribes Antochini and Hexatomini (in the* 

 strict sense)^ seem to be entirely lacking so far as known. The Pty chapter idae 

 are likewise lacking and the single record for the Tanyderidce (Protoplasa) is 

 unsatisfactory. 



Adult Flies. 



Family TIPULID^. 



Subfamily LIMNOBIINOE. 



Tribe LIMNOBIINI. 



Genus Dicranomyia Stephens. 



Dicranomyia Stephens; Catalogue of British insects, vol. 2, p. 243; 1829. 



Dicranomyia alascaensis, n. sp. 



Antennae black; halteres short; wings nearly hyaline, with a large, oval, 

 brown stigma; Sc 2 remote from the tip of Sci; cellars* M2 closed; femora yellow, 

 tipped with brown. 



» Concerning the status of the tribe Hexatomini, read the remarks under the genus 

 Poedlostola, page 000. 



