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propriety of the location originally given by Linnaeus, and to obviate, in some degree, 

 the incongruity of its situation, Latreille was induced to construct for it an indepen- 

 dent genus, placed beside Panorpa, to which genus he gave the name Boreus. The 

 hyemalis has remained to this day the sole species of this genus, no other insect hav- 

 ing similar characters, having been discovered in any part of the world. Two years 

 since, in the month of March, searching carefully upon the melting snow, to find if 

 possible in this vicinity, a rare and singular insect which has been lately discovered in 

 Canada — the Chionea valga, a fly destitute of wings — though unsuccessful, my labours 

 were rewarded with an equally acceptable return, an insect co-generic with the curious 

 Boreus hyemalis of Europe. Since that time, I have met with numerous specimens, 

 and have also found, in the same situations, several individuals of a third species per- 

 taining to the same genus. 



" 1. Boreus nivoriundus. The Snow-born Boreus. 



" Shining black or brownish black ; rudimentary wings, thorax above, with the 

 rostrum and ovipositor excepting their tips, fulvous ; legs dull fulvous. 



" Length, male 0.12 in. ; female 0.15, or including the ovipositor 0.18. 



" This insect is by no means rare, being found upon the snow in forests in warm 

 days, so early as December, and becoming more plentiful as the season advances. I 

 have met with it the most plentifully in April, when there has been a fall of snow in 

 the night, succeeded by a warm forenoon of bright sunshine. Appearing so suddenly, 

 in numbers, upon the clean, dazzling white surface thus spread over the earth, at the 

 first thought it seems to be literally bred from the snow. I have not yet searched for 

 it in the moss of tree-trunks, but doubt not that like the European insect, ours will 

 also occur in this situation. When observed upon the snow, it is almost always sta- 

 tionary ; and when approached by the hand, it commonly makes a leap to the distance 

 of a few inches ouly, its saltatory powers appearing but feeble. 



" 2. Boreus brumalis. The Mid-winter Boreus. 



" Polished deep black- green ; legs, antenna?, rostrum, aud ovipositor black ; rudi- 

 mentary wings brownish black. 



" Length, male 0.10 ; female 0.12, or including the ovipositor 0.15. 



" So far as I have at present observed, this appears abroad earlier in the season, 

 and in colder weather than the preceding, though occasionally found associated with it 

 on the last snows that fall in the spring. It is much less common than the other. 



" 3. Perla nivicola. The Small ' Snow-fly.' 



" Black ; wings gray, unclouded, a third shorter than the abdomen in the males, 

 a third longer in the females. 



" Length 0.20, wings expand 0.45 ; males smaller. 



" On warm days in the latter half of winter, this species may be observed crawling 

 with hurried steps upon the snow. It becomes most numerous about the time the 

 snow finally disappears, and is then often seen on shrubs, fences, and buildings, and 

 not unfrequently finds its way into our houses. It is extremely common, occurring 

 most abundantly in the vicinity of streams of water, in which element the previous 

 stages of its existence are passed. When first excluded from its pupa state, it is of a 

 pale yellowish colour, but gradually changes to black, this change commencing upon the 

 thorax. Copulation occurs immediately after the female comes from the pupa state. 



