278 



this last is another tubercle in most segments, which is tipped with hairs 

 only. The feet are pale reddish or ochreous. The body beneath, whitish, 

 spotted with black. There are numerous, short, whitish hairs or bristles on 

 the head and body. In many of these larva? there is a blackish lateral line 

 above the yellow one, and a large blackish spot surrounding a smaller yel- 

 low one in front of the upper lateral spine. The yellow color frequently 

 forms small transverse lines, especially on the margins of the segments above. 

 The younger the larvae the more does the black color prevail, so that it 

 appears to constitute the prevailing hue of the youngest larva;. 



No perceptible difference was observed in larva; from the Cnictts and 

 Onopordon, except that the full-grown ones of the latter had less black about 

 them, so that the dirty bluish white color of the body was more prevalent 

 and observable. In small larvre of the thistle several days old and about four 

 tenths of an inch long, the whole body, head, spines and feet, were black, 

 but there was a faint yellowish spot around the first lateral spine (or tuber- 

 cle) of the fifth, seventh, and ninth segments. As the larva grows older 

 these appear like six yellow spots; afterwards there are spots around the 

 dorsal tubercles in the same segments, and the spines from each of these 

 yellow tubercles become yellow also, and there is a yellowish, interrupted, 

 lateral line upon the fourth and remaining segments. The larva has then 

 become more than half an inch long. After another sloughing the dorsal 

 yellow lines appear, and there are a few yellowish spots on the posterior 

 half of the body. After every successive change of skin the larva becomes 

 lighter, till at length it assumes the hues of the full-grown insect before 

 described. 



A larva on a hollyhock about to suspend itself exhibited transverse, bluish 

 white bands across each segment, on which the spines were situated, the 

 tubercles of which were not reddish, but pale blue. The longitudinal, dor- 

 sal, yellow lines obsolete. Two transverse ochreous bands between each 

 segment and a little spot of the same color in front of each lateral tubercle. 



Found a larva on the leaf of a sunflower, Aug., 1822, from which my 

 drawing was made. [PL i, figs. 1, 2.] 



Head black, with white hairs ; middle of the back with a yellowish line in 

 which are situated white, branched spines tipped with black ; each side of 

 the yellow line a row of yellow tubercles with branched spines upon the 

 edge of a black line; just below, upon the lower edge of this black line, is 

 another row of branched spines, which is wide, and upon the upper edge 

 another narrow yellow line; then a narrow blackish line, in which are the 

 spiracles, which are black within, a lighter color encircling them; next a 

 yellow line, brighter than the former, with tubercles and white spines, not 

 tipped with black; next is the belly, of a light ash color, and hairy; feet 

 light ochreous yellow; tip "of tail black; true feet ferruginous, tipped with 



