199 



Alaska, several specimens taken on marshes, near Saint Michael's, Sep- 

 tember 20, 1867, clinging to blades of grass (Dall, Mus. Peab. Acad. Sc.) ; 

 White Mountains, N. H., November (Packard, Mus. Peab. Acad. Sc); Fort 

 Randall, Dakota Territory (Dr. E. Coues); London, Canada (Saunders); 

 Portland, Me. (Morse); Norway, Me. (S. I. Smith, Mus. Comp. Zool.); 

 Andover, Mass., November (Sanborn, Mus. B. S. N. H.); Natick, Mass. 

 (Stratton, Mus. B. S. N. H.); Brooklyn, L. L, N. Y. (Graef). 



This species is not so common with us as in Europe, where it rivals 

 Anisoptcryx in its abundance and injurious effects. The only difference I 

 can detect between this and O. brumata (Linn.) is in the form of the discal 

 space of the hind wings; in the latter, the outer end is broader and more 

 rounded than in most of my examples of O. boreata, the distance between the 

 origins of the second and third median venules being less in brumata than 

 in boreata. Judging by the males of the two species labeled by Professor 

 Zeller, I do not see on what grounds boreata should be separated from brumata. 



The males differ but little except in size and in slight variations of 

 venation. The most striking variation is afforded by a large male from Nor- 

 way, Me., which is of a sea-green tint. The moth is liable to be confounded 

 with Anisopterijx vernata, from which it may be readily recognized by the 

 more rounded fore wings, its ochreous tint, the many waved linos, and, lastly, 

 by the entirely different plan of venatiou. 



Larva. — Newman thus describes the larva of O. brumata; — Head scarcely 

 as wide as the body, and scarcely notched on the crown; the body is rather 

 obese, deceasing in size toward each extremity. Head pale green, semi- 

 transparent. Bod}' glaucous-green, with a narrow, median, blackish stripe on 

 the back, and three narrow white stripes, at equal intervals, on each side. 

 The caterpillar of O. boreata is very similar to that of the winter-moth, but 

 more transparent, and the stripes more indistinct, but it chiefly differs from 

 that very common species in having a brown head, that of the winter-moth 

 (0. brumata) being pale green and semi-transparent. It feeds on birch. 



Subfamily FIDONIM] Guenee (emend.). 



Family Ataiaridtr Guen., Plial., ii, HI, is.",". 

 Family Fidonidas Guen., Phal., ii, 95, 1857. 

 Family ZerenidiB Gueu., Phal., ii. 195, 1857. 



This subfamily may be distinguished by the usually square front, the 

 usually rather slender palpi, which are as a rule rather long, always passing 



