447 



river and connected lakes during the last week of April and the first 

 week of May, 1914. As tentans occurred at the same time and place 

 and no exuviae from reared material are available for comparison 

 there are no data for determining what percentage of each species was 

 present, though they probably occurred in about equal numbers if one 

 may judge from the imagines of each that appeared. 



Originally described from Europe and recorded subsequently from 

 Washington State. 



28. Chironomus plumosus Linne 



Tipula plumosa Linne, Syst. Nat., ed. 10, 1758, p. 587, sp. 19. 

 Chironom/us plumostis (Linne) Meigen, Klass. 11. Beschr. Zweifl. Eur. Ins., Vol. 1, 

 1804, p. 11, sp. 1. 



Johannsen has provisionally identified as the larva and pupa of this 

 species specimens taken from swamps in the vicinity of Cayuga Lake, 

 Ithaca, N. Y. His descriptions are as follows : — 



Larva. — "Blood red, length of body about 22 mm. Head brown, 

 antenna short and stout, basal joint about half as long as the mandible ; 

 the latter with blackened teeth and with the usual mesad projecting 

 setse. Labrum, epipharynx, and hypopharynx were destroyed. Max- 

 illa with short palpus and a mesad projecting lobe with setae and pa- 

 pillae. . . . Labium broad, with short blunt teeth [PI. XXXH, Fig. 

 4] ; the middle tooth broad, with a nearly straight apical margin, the 

 first lateral small and more or less rounded, the second lateral broad 

 and a little longer than the middle one ; the third pair smaller and 

 closely united with the second ; fourth, sixth and seventh laterals about 

 of ecjual size with rounded margins, the fifth slightly smaller. Ante- 

 rior prolegs with very numerous fine hairlike setae. Ventral and anal 

 blood gills present." 



Pupa. — "Grayish brown in color ; the markings of the enclosed 

 imago visible; length about 16 mm. Respiratory filaments much 

 branched and whitish in color. The dorsum of the abdominal seg- 

 ments uniformly covered with microscopic spines, those nearest to the 

 posterior margins of the segments a little stouter than the others. The 

 lateral fin on the eighth segment terminates in a chitinous process or 

 spur, the extremity of which is divided into 7 or 8 spines in close con- 

 tact. . . . Caudal fin with the usual fringe of matted filaments," 



Figure 4, Plate XXXII, is a reproduction of Johannsen's figure of 

 the larval labium. 



Imago; Male. — Yellow, occasionally with a greenish tinge. Head 

 yellow, antennae with the exception of the basal 3 joints of flagellum 



