310 INSECTS IXJUKIOUS TO VEGETATION. 



is another purple-brown spot, covering nearly the whole of the 

 outer hind margin of the fore wings, and united to the band 

 near that part ; the body is yellow, shaded with purple-brown 

 on the back, and with three spots of the same color on the 

 thorax. It expands from four inches and a half to more than 

 five inches. In a variety of this moth, of which I have a 

 colored drawing done by Mr. Abbot, the purple-brown color 

 prevails so much as to cover the wings, with the exception only 

 of a large triangular yellow spot contiguous to the front margin 

 of each wing. This moth appears here from the twelfth of 

 June to the beginning of July, and then lays its eggs on the 

 button-wood tree. The caterpillars may be found upon this 

 tree, grown to their full size, between the twentieth of August 

 and the end of September, during which time they descend 

 from the trees to go into the ground. They are then from 

 three to four inches in length, and more than half an inch in 

 diameter, and, for the most part, of a green color, slightly 

 tinged with red on the back ; but many of them become more 

 or less tanned or swarthy, and are sometimes found entirely 

 brown. There are a few very short hairs thinly scattered over 

 the body ; the head and the legs are pale orange-colored ; the 

 oval spiracles, or breathing holes, on the sides, are large and 

 white, encircled with green ; on each of the rings, except the 

 first, there are six thorny knobs or hard and pointed warts of a 

 yellow color, covered with short black prickles ; the two up- 

 permost of these warts on the top of the second and of the 

 third rings are a quarter of an inch or more in length, curved 

 backwards like horns, and are of a deeper yellow color than 

 the rest ; the three triangular pieces on the posterior extremity 

 of the body are brown, with yellow margins, and are covered 

 with raised orange-colored dots. The chrysalis, which is not 

 contained in a cocoon, is about two inches long, of a dark 

 chestnut-brown color, rough with little elevated points, particu- 

 larly on the anterior extremity, ends behind with a long forked 

 spine, and is surrounded, on each ring, with a notched ridge, 

 the little teeth of which point towards the tail. Three of the 

 grooves or incisions between the rings are very deep, thus al- 

 lowing a great extent of motion to the joints, and these, with 



