xiv TABLE OF CONTENTS. 



Perla nivicola, the Small " Snow-fly " 239 



Description, time of appearance, habits, abundance, colora- 

 tional changes, etc., 239. 



Nemoura nivalis, the Large " Snow-fly; " the " Shad-fly " 240 



Minutely described, 240. Colorational changes in the imago ; 

 is infested with an Acarus parasite ; time of appearance ; furnishes 

 a food-supply for fishes ; its European analogue, 241. 



CuLEX hyemalis, the Winter " Musketoe " 241 



Description, time of appearance and rarity, 241-2. 



CiiiRONOMUS nivoriundus, the Snow-born Midge 242 



Description, 242. A very common species ; myriads observed 

 on one occasion, 243. 



Trichocera brumalis, The Mid-winter Trichocera 243 



Briefly described, its habits and resemblance to an European 

 species, 243. 



Podura nivicola. " The Snow-flea " 244 



Description, comparison with other species, its abundance in 

 forests on the snow, and floating upon water, etc., 244. 



GENERAL INDEX 245 



PLANT INDEX 



