38 c Canadian Arctic Expedition, 1913-18 



Pupa. Similar to that of tentans. The second abdominal segment has a 

 transverse line of minute chitinized spinules on posterior margin, and almost 

 the entire dorsal surface covered with small brown scale-like eleva- 

 tions, which are most conspicuous posteriorly; a rather long hair is present 

 on each side of median line posteriorly, and the elevations are absent round the 

 bases of those as well as on a number of small round areas on anterior half of disc; 

 segments 3 to 5 without transverse line posteriorly, but in other respects as 

 second, though the elevations, or scales, become progressively weaker to fifth 

 segment and are present only near posterior margin on sixth and seventh as two 

 small brown patches; eighth segment with each postero-lateral angle armed 

 with a chitinized process similar to that of decorus Johannsen. 



Length, 14 mm. 



Locality: Pool at Collinson point, Alaska, June 22, 1914 (F. Johansen). 



Chironomus, sp. 3. 



Larva. This species differs from the previous one only in being smaller, 

 11 mm., and in having a dark brownish vitta on dorsum of head, and the sub- 

 median labial tooth attached to median one so that it appears more like a pro- 

 tuberance from the side of the latter than a distinct tooth. 



Locality: Brackish pond, Bernard harbour, Dolphin and Union strait, 

 Northwest Territories, August 4, 1915 (F. Johansen). 



Tanytarsus Van der Wulp. 

 There are several imagines and some larvae of this genus in the collection. 



Tanytarsus, sp. 1. 



Five males in poor condition resemble in most particulars viridiventris 

 Malloch. The thorax is black, abdomen fuscous, though probably greenish in 

 life, and legs pale fulvous. The fore tarsi have no long hairs and the basal joint 

 is about 1 -5 as long as second. The wings are not in good enough condition to 

 give an accurate idea of the venation. 



Length, 3-5 mm. 



Locality: Teller, Alaska, August 3, 1913 (F. Johansen). 



Tanytarsus, sp. 2. 



One male without fore tarsi. Larger than foregoing. Entirely black, 

 including the legs, halteres, and antennal plumes. Wings with very short 

 surface hairs; radius extending to beginning of apical curve of wing; cross-vein 

 slightly before middle. 



Length, 4-5 mm. 



Locality: Lake Angmaloktok, Colville mountains, Wollaston peninsula, 

 Victoria island, July 22, 1915 (D. Jenness). 



Tanytarsus, sp. 3. 



Larva. Orange in life; alcoholic specimens, greenish yellow, head brown. 



Base of antennae pedunculate; basal antennal joint about five times as long- 

 as thick, second joint about one-fourth as long as basal, third and fourth joints 

 pale, their combined lengths not equal to length of second and distinctly less than 

 that of the long pair of filaments at apex of second joint, the filament at apex of 

 basal joint not longer than second joint; mandibles stout, with a rather strong, 

 and not very sharp apical tooth, and three small teeth along inner margin: 



