LIBYTHEA. 



to the right or left by a corresponding movement of its head, whereby to attach 

 its unsteady bridge to a neighboring Hne or leaf 



When ready to transform, they spin buttons of red silk upon tlie side of a 

 leaf, suspend themselves as do the i^t/mjjhalidce, and in about eight hours I)ecome 

 chrysalids. The chrysalis is a beautiful object, of a delicate green, ornamented 

 with yellow lines, and helmet-shaped. 



I have noticed another remarkaljle peculiarity in these larva^. On 30th Au- 

 gust, I returned home after an absence of but three days, and found the leaves 

 that I had placed in the glass with four larva\ which had jvist passed their third 

 moidt at my departure, dried up and all the larvce changed to cJirysaUds, thus 

 crowding into less than three days changes which naturally require six. The 

 chrvsalids were not more than half the usual size, and the butterflies that came 

 from them were small and pale colored. Twice also I inclosed larv* just after 

 their third moult, in a tin box with fresh leaves, and forwarded by mail to Miss 

 Peart, who was then near Philadelphia, expressly to secure a drawing at that 

 stage, and before fourth moult, which should not occur till the fourth or fifth day 

 .after the third moult. But though the distance was only two days, in one case 

 the larva on its arrival had fixed for chrysalis, and in the other had actually 

 changed. Miss Peart wrote, on 1st August, that the larva mailed 29th Jtdy had 

 arrived 31st, hut was in chrysalis, and from no ivant of food, as the leaves were 

 fresh. I should apprehend, therefore, that in these cases the larvse had not 

 passed the fourth moult, l)ut had proceeded to chrysalis directly from the third. 

 Apart from the difference in size, there is no mistaking the third moult for the 

 fourth, from the peculiar markings assumed at this last. 



All the caterpillars of Bachmani observed in 1872 were green, and I should 

 not then have credited a statement of variation in color. But of those fed in 

 1873, several were marked more or less with black, in spots or bands. 



I am not aware of any other food-plant for this species than Celtis occidentaUs. 

 This tree is a favorite with many other larvtB, especially of the Apatiiras, Celtis, 

 and Clyton, and Grapta interrogationis. G. comma will feed on the leaves in 

 confinement, but unwillingly. 



