Diptera 

 CHIRONOMINiE. 



There are representatives of several genera of this subfamily in the colled 

 some of them represented by larval and pupal stages and some by imagii 



Diamesa Meigen. 



This genus is represented in the collection by one species which does 

 not agree in structure with any species known to me. 



The larva? of Diamesa species are generally found in fasl running water 

 and normally on rock surfaces. I have seen females thai were collected while 

 in the act of ovipositing in water caused by the melting of -now on mountains 

 in Montana. 



Diamesa arctica, n. sp. 



Female. — Black, subopaque. Wings subfuscou-. veins thick and dark. 

 cross-vein infuscated. Halteres brown. 



Eyes very widely separated, width of frons equal i<> one-half the width 

 of head; antenna? with 8 joints, the apical one four times as long a- preapical, 

 surface hairs long and rather numerous. Pronotuin with a deep, moderately 

 wide central, wedge-shaped incision; dorsum of me-onotum and scutellum 

 with rather long fuscous hairs. Abdomen stout, with shaggy fuscous hair.-. 

 Legs stouter than in Walllii Meigen, and with much more conspicuous hairs; 

 fore tarsi with the basal joint very little more than one-half as long a- fore 

 tibia; fourth tarsal joint on all legs sub-equal to or very little shorter than fifth; 

 mid tarsi with a series of minute erect setulae on ventral surface of at leasl 

 the basal two joints. Venation similar to that of Wall Hi. 



Length, 4 • 5 mm. 



Type locality: Colville mountains, WollastoD peninsula, Victoria island. 

 July 22, 1915 (D. Jenness). Paratype, lake Angmaloktok, Colville mountains, 

 \Yollaston peninsula, Victoria Island. July 29, 1915 (D. Jenness 



Chironomus. 



There are larva? and pupa? of one species and one imago of possibly another 

 species of this genus in collection. 



Chironomus, sp. 1. 



A male in rather poor condition resembles closely several species I ha 

 described from Pribilof islands. It is entirely black and ha- the fore tarsi 

 long-haired, characters common to nearly all male- of this genus ha\ 

 from the far north. Structurally the specimen agrees very well with one 

 I have described as conformis in a paper now in pre--. bu1 more specimens 

 are necessary to ensure an authentic identification. 



Length, 7 -5 mm. 



Locality: Baler island, Arctic coasl of Alaska, July 2 I'M I D. Jenness . 



Chironomus, sp. 2. 



Larva. — Bright red in life. Labium very similar to thai of tentana 

 Fabricius, but the median tooth is regularly rounded and the small submedian 

 one larger than in that species: the mandible has three teeth in addition to the 

 large apical one. The ventral and respiratory filaments are absent, the dorsal 

 papillae are small, each with eighl long hair-, and the four apical respirat< 

 protuberance- between the caudal pseudopods arc about three time- a- Ion- 

 thick. 



Length, 17-19 mm. 



