BOMBYCID^. CNETHOCAMPA. 47 



medicinally, no less than two enactments of the Roman senate pro- 

 hibited, under severe penalties, by reason of their virulence. The 

 pupae are gregarious, and bidentate posteriorly : the eggs are en- 

 veloped in down. 



t Sp. 1. processionea. Alts cinereo-fuscis : fceminoe strigd obscuriore, maris 

 tribus. (Exp. alar. $ 1 unc. 3 — 5 lin. : j 1 unc. 4 — 8 lin.) 



Ph. Bo. processionea. Linne. — Martyn{\) — Cn. processionea. Steph. Catal. 

 No. 5995. 



Antennae dusky-brown : head and thorax ashy-gray : abdomen brownish, with the 

 apex dusky : anterior wings ashy-brown, with three waved, dusky, or black 

 strigae, two approximating near the base, the other towards the hinder margin : 

 posterior wings paler, with one oblique striga : female more obscure, with an 

 indistinct fascia near the base, and an obsolete dusky striga towards the hinder 

 margin of the anterior wings : posterior wings dull ochraceous, with an in- 

 distinct fascia. 



Caterpillar blackish on the back, with cinereous-brown lines on the sides, and 

 yellowish dorsal spots : feed on the oak, and change into pupae, anteriorly 

 brown, posteriorly yellowish, in a common receptacle : each larva forming a 

 separate rigid cocoon of silk and hair for itself, and the whole being arranged 

 in the nest like the cells of the honey-comb. 



The larvae, when first hatched, construct a temporary nest for themselves on the 

 branches of the oak, and change their situation from time to time, until they 

 are about two-thirds grown, when the entire brood unite in forming a general 

 nest on the trunk : this nest, when completed, is about eighteen inches long, 

 six broad, and composed of a gray silk, resembling the surface of the tree : 

 but the most curious fact in their history is the extraordinary regularity with 

 which the larvae proceed, towards sunset, in search of food : at their head is 

 a chief, by whose movements their procession appears regidated ; he is followed 

 by three or four in a single line, the head of the second touching the tail of 

 the first, &c. : then comes an equal series of pairs, next of threes, and so on 

 as far as fifteen or twenty, forming a band several feet in length : sometimes 

 the order is rather different, the leader being followed by two, then three, 

 four, and so on ; but at all times the procession moves on with an even pace, 

 each file treading upon the steps of those that precede it, through all the 

 sinuosities made by the chief. They do not invariably return to their nest 

 before morning, but may sometimes be found during the day assembled in 

 irregular masses, heaped upon each other. 



Martyn introduces this as a British species, and Stewart has followed his ex- 

 ample; but I have not seen an indigenous specimen; the one reputed to be 

 in the British Museum being apparently a stunted female of Cn. Pityocampa. 

 It is said there is great danger in approaching the nests of this species, on ac- 

 count of the fragments of hairs which float about in its vicinity, wliich renders 

 it a fortunate circumstance that the insect does not inhabit Britain, although 

 the contemplative entomologist must necessarily be debarred from the in- 

 teresting spectacle of their procession. 



