NATURAL HISTORY. Ixxvii 



either from the males appearing earher or later, or from their not being sanguinary ; 

 I have frequently for a week together found the females of Ctilex annulatus con- 

 gregated in summer-houses in gardens, without being able to discover a single male.* 



Commander Ross remarks, "Of this genus only one species was observed. It first 

 appeared about the 10th of July, on the 15th it became very numerous, and on tlic 

 22d so extremely troublesome, as to prevent the necessary duties of the ship. They 

 were in perfect clouds over the marshes, and their larvae constitute the principal food 

 of the trout that inhabit the lakes. It was only in the beautiful summer of 1830 that 

 we found them so very numerous. On the 13th of August of that year they came 

 out again after the rain, but were no longer very troublesome, being apparently nipped 

 by the frost at night ; indeed soon after this time the ground was again covered with 

 snow, and all entomological observations were terminated." 



Fam.— TIPULID^. 

 tGEN. 1140.— CHIRONOMUS. {Meig.) 



27. Polaris. (Kirb.) Black hairy, wings lacteous, iridescent, the costa fuscous, 

 with the nervures darker, halteres dirty ochre. 



Length three lines and three-fourths, breadth six lines. 



Ch. Polaris. Kirby in Stipp. to App. of Capt. Parrifs ]st Voyage — p. ccxviii. 



PI. A, fig. 14, female ; fig. 2, head of same in profile. 



No males of this species were brought home, and only three females, none of which 

 retained their first pair of legs, which are therefore merely sketched in the plate to 

 show their situation. 



28. Borealis. Black, thorax grey, abdomen with seven whitish rings ; costa fuscous ; 

 legs lurid. 



Length three lines, breadth six lines. 



Black, basal joint of antennae ochreous ; thorax hoary ; abdoirien clothed with long 

 subdepressed yellowish hairs, the margins of the segments shining whitish or silvery ; 

 wings lacteous, opalescent, the costa fuscous, the nervures darker ; halteres yellowish ; 

 legs dull castaneous ochre, tips of the thighs and tarsi fuscous. 



Only one specimen has come under my observation, and that had lost its antenna 

 and some of its legs. 



* Curlis's Brit. Ent.— vol. xii., fol. 537. f lb.— vol. ii., fol. 90. 



