lo-r 



GRAPTA I. 



which lie along the costal iiervure, separated by a very small interval, and each 

 edged by a velvety black line ; the third, along median nervure, illy-defined with- 

 out such edging ; the spot on disk of secondaries dead white, l^ent at right angles ; 

 the lower limb straight, thick, abruptly sloping to a point by tlie cutting away of 

 its upper side ; the upper branch narrower, slightly carved, nearly as wide at top 

 as elsewhere and ending bluntly ; fringes with the white area more extended 

 than on upper side. 



Body above black, covered with ferruginous hairs, l^elow black, sometimes 

 with a gray shade ; legs gray-brown ; pal2ii black at liase and in front, with 

 whitish hairs at sides, ferruginous at top ; antennae black above, fulvous below ; 

 club black, fulvous at tip. 



Female. — Expands from 2.1 to 2.3 inches. 



In shape very like the male ; upper side dull yellow-fulvous, the spots large ; 

 under side more brown than black, the extra-discal area to margin pretty uniform 

 in shade, the ground being dark gray, nearly lost in the denseness of the l)ro\vn 

 streaks; sub-marginal points and crescents obsolescent; silver mark of same 

 shape as in the male, often quite as heavy. 



Larva miknown. 



Silenus is found in Western Oregon and in San Juan and Vancouver's Islands, 

 where it flies in company with Satyrus. It may be readily distinguished by 

 the general blackness of both surfaces, by the large size of the black spots on 

 upj^er side, by the obsolescence of the usual sub-marginal crescents on under 

 side, and by the character of the silver spots. In this last respect and in shape 

 of wings it is near Gracilis ; in the deep fulvous color, Faiinus ; in the sub-mar- 

 ginal crescents of under side, Progne ; but in important respects differs from 

 each of these. 



The genus Grapta is well represented on this continent, a greater number of 

 species being already known than in the ^vorld beside. And as several are very 

 local in their habit, it is highly proljable that others remain still to l)e discovered. 

 Our knowledge of the butterflies of the entire Rocky Mountain district — except- 

 ing Northern Colorado — and of the vast extent of territory to the Northwest 

 and North, amounts as yet to a mere nothing, restricted literally to the scanty 

 collections of the government surveying expeditions, and an occasional specimen 

 from some chance traveller. It is noticeable that the American Graptas show little 

 tendency to riui into varieties. In a series of an hundred Comma, or as many 

 Faunus, all will be essentially alike, not differing between themselves to a greater 

 degree than a number of Cardui or Atalanta. And in the case of those species 

 that are dimorphic, I find the two forms of each nowhere convergent. This is 

 remarkable, because there is a general similarity between so many of the species 



