NYMPH ALINAE: THE GENUS BASILARCHIA. 257 



The butterflies of this <rciiu.s, iiioludiu;^ -some of our showiest forms — the 

 very queens of butterfly society — sliovv their depraved taste in a fondness 

 for the ordure of animals fallen in the road. Their flight is lofty and sail- 

 ing and they arc usually wary and easily alarmed. When restino- in the 

 sun and espcc^ially wlicn u[»on the leaves of trees tiiey often remain a long 

 while with broadly expanded wings. When in the shade their wings are 

 folded back to back, and the antennae are spread at an angle of about 60" ; 

 the latter are very nearly straight, but slightly bent, with a broad curve 

 at about the middle, so as to bring the tips a little nearer together. 

 "When walking, and occasionally when at rest, they feel the surface 

 before them, sometimes with both antennae together, sometimes alter- 

 nately. 



There is no American genus of butterflies, the habits of which in the 

 earlier stages are more interesting than those of Basilarchia. The eggs are 

 laid upon the extreme tip of acuminate leaves (the allied families of Cupu- 

 liferae, Betulaceae and Salicaceae are the favorite food plants of the larva), 

 and the little caterpillar devours first that end of the leaf, sparing 

 the midrib, to which it always retires after a meal. The further perfor- 

 mances of the creature have been so well told by Mr. Edwards, that I 

 give his account of them in an abbreviated form (Butt. N. Am., ii). 

 The end of the rib is no sooner laid bare than it is coated and wound with 

 silk, of the use of which these caterpillars are exceptionally free, and to this 

 extremity are fixed bits of bitten leaf as small as grains of powder ; at 

 first there are but two or three in line, but the number is afterwards 

 increased, and they probably serve to stiffen the perch and prevent its 

 curling as the rib dries. "It is constantly strengthened by additions of 

 silk, the larva almost invariably, as it goes back and forth from its feeding 

 ground, adding threads and patching the weak places." When not feeding 

 the caterpillar always occupies this perch, the head outward; " its usual 

 attitude is a twist, the ventral legs clasping, but the anterior half of the 

 body is bent down by the side of, and somewhat under, the perch." It 

 has the curious habit of accumulating little scraps of leaf at the base and 

 under side of the perch into an open packet, and this is moved as the leaf 

 is eaten, so as always to be close to the cut edge of the leaf. This edge, in 

 narrow leaves, and at first in broader ones, is kept nearly square by 

 eating first on one and then on the opposite side of the leaf. Occasionally 

 a canal is eaten from the edge of the leaf, parallel to the eaten edge all 

 the way to the midrib ; as the bit of leaf thus left unsupported begins to 

 droop, guys are spun from it to the solid leaf on the opposite side of the 

 canal and to the midrib : it is then eaten away from the leaf, and the 

 triangular bit remaining falls hanging by its threads and swings to the 

 base of the perch or is pulled there by attaching successively shorter 

 threads. The packet is left behind and not increased after the second 



