401 



green colour, with a darker line down lli<' middle of llu- i);iek, margined on 

 both sides with a series ol' whitish marks". It i'vnU nn the Itroom, elm, liorn- 

 l)eam, birch, and oak. It is Ibund in Sei)1end)er, and airain in ^lav, liviu"- 

 thronurh tlu' winter. 



'O' 



Mktrocampa pf.rlaria Guent'e. Plate 12, lig. 1. 



Melrocampa pcriaia Giikh., Plial., i, I'JH, 18.")". 



Walk., List Lep. Ilet. Br. Mils., xx, ir.7, 1860. 

 itclrocampa rirido-perlaia i'ack., Prof. Bost. Soc. Nat. Hist., xvi, :W, 1S74. 



5 <? and 7 9. — Pearly-whitt.^ with a decided greenish tinge. Body, 

 antenna:', and feel snow-white. Front white ; a transverse reddish line just 

 below the antennje, but never extending l)elow on to the front. Fore wings 

 crossed by two broad, ditFuse, white lines, bordered widely within with pale 

 brown, which fades into the ground-eolor ot" tiie wing; both lines are straight. 

 Fringe white. Beneath white: the lines iiot reproduced beneath. 



It is, contrary to Gnen^e's statement, as large as the Furo])ean marga- 

 ritacea, but may perhaps often be smaller; but the angle of the hind wings 

 is no more marked than in the European, but, as he says, the outer line 

 terminates nearer the apex, and this is the best character to separate our two 

 American species from the European, while the front of the European is 

 redder, the front edge of the front being white, and the wings uniformly 

 greener. 



Length of body, 3, 0..f)0-0.60, 9, 0.50; of fore wing, 3, 0.75-0.85, 9, 

 0.90-1.00; expanse of wings, 1.45-2.00 inches. 



Montreal, Canada (Lyman) ; Brunswick, Me. (Packard); Portland, Me. 

 (Morse); White Mountains, N. H.. July 20-30 (Scudder); N(;w York (Grote); 

 West Farms, N. Y. (Angus); Philadelphia, Pa. (Ent. Soc). 



This species, at once recognized l)y its pearly-white color and greenish 

 tinge, difi'ers only from the European ?nargantana in the extradiscal line 

 being bent at right angles on the costa, while in the European species there 

 is only a slight curve. 



Although I originally regarded two Californian examples as distinct from 

 the eastern perlata, on further comparison with more material (2 i and 5 9) 

 from Vancouver Island, I can see no differences of importance. Th(> western 

 ones are a little larger tlian the eastern. 



Length of wing of Vancouver's Island specimens, c?, 0.85, 9, 1.00; of 

 a 3 from New York, 0.75; of a 9 from White Mountains, N. IT, 0.90, and 

 one from Philadelphia, Pa., 0.95 inch 



