424 LEPIDOPTERA. 



is found in August and September on plum and apple trees, 

 and, according to Mr. Abbot,* on the red-berried alder, 

 Prinos verticillatus. The top of the fourth ring of this cat- 

 erpillar rises in the form of a long horn, sloping forwards 

 a little ; the tail, with the hindmost feet, which are rather 

 longer than the others, is always raised when the insect is 

 at rest, but it generally uses these legs in walking ; its head 

 is large, and of a brown color ; the sides of the second and 

 third rings are green ; the rest of the body is brown, vari- 

 egated with white on the back, and on it there are a very 

 few short hairs, hardly visible to the naked eye. When 

 fully grown, it measures an inch or more in length. Though 

 mostly solitary in their habits, sometimes three or four of 

 these caterpillars are found near together, and eating the 

 leaves of the same twig. Towards the end of September 

 they descend from the trees, and make their cocoons, which 

 are thin and almost transparent, resembling parchment in 

 texture, and are covered generally with bits of leaves on the 

 outside. The caterpillars remain in their cocoons a long 

 time before changing to chrysalids, and the moth does not 

 come out till the following summer. There are probably 

 two broods in the course of one season, for I have taken 

 the moths early in August. In Georgia the caterpillar made 

 its cocoon on the 30th of May, and was transformed to a 

 moth fourteen days afterwards. This moth is the Xotodonta 

 unicornis, or unicorn moth, so called from the horn on the 

 back of the caterpillar. The fore wings are light brown, 

 variegated with patches of greenish white and with wavy 

 dark brown lines, two of which enclose a small whitish space 

 near the shoulders ; there is a short blackish mark near the 

 middle ; the tip and the outer hind margin are whitish, 

 tinged with red in the males ; and near the outer hind angle 

 there are one small white and two black dashes ; the hind 

 wings of the male are dirty white, with a dusky spot on 

 the inner hind angle ; those of the female are sometimes 



* Insects of Georgia, p. 171, pi. 86. 



