8 BRITISH LEPIDOPTERA. 



cast skin, except the head, but it does not appear to specially eat up 

 the leaf with the silken carpet on which it has rested, as our Ceritrae 

 invariably do when possible." 



Miss Golding-Bird stated (Enlom., ix., p. 270) that, in the young 

 larva of Staurojms fagi, the process of moulting lasted about half an 

 hour, that the legs " did not all get free till the skin had been pushed 

 back to the 6th segment (? 2nd abdominal), and that then even the 

 flattened tail made its way out with comparative ease." Birchall also 

 notes (Ent. Mo. Mag., xiii., p. 232) that there was not the difficulty in 

 a larva of Staurojms fagi changing its skin that he "had expected 

 from its singular form and varying diameter." The three pairs of 

 legs, he says, "were drawn out from the old shells precisely after the 

 manner of a crab or lobster, but with much greater ease, owing to the 

 small amount of contraction at the joints, a few seconds only being 

 needed for the operation. The new legs on emergence are semi-trans- 

 parent and apparently soft, and are at once folded up against the fore- 

 part of the larva, which then rests for a few minutes, for the purpose 

 of allowing the newly-developed legs to acquire colour and hardness 

 by exposure to the air ; in about five minutes they are unfolded, and 

 the work of extricating the body proceeds ; the swollen terminal 

 segments offer no difficulty, the old skin seeming to possess great 

 elasticity." 



Buckler considers the last larval moult of Staurojms fagi to be 

 a very exhausting operation and describes (Ent. Mo. Mag., xvii., p. 18), 

 at length, an ecdysis that apparently commenced on September 3rd, 

 1879, when the larva was noticed as already having a double-headed 

 appearance, from the real head being mostly within the skin of the 

 prothorax. It was grasping a twig with the four pairs of ventral 

 prolegs, and all the front segments were stretched, arching backwards 

 over the erected broad segments of the tail, thus forming a more or 

 less circular position. At long intervals the fore-part of the body was 

 gently raised up and down a little, sometimes varied with a kind of 

 convulsive heave, and once, after many hours' stillness, the anterior 

 legs were extended laterally to their utmost stretch, quite rigid for a 

 couple of minutes, and were then gradually refolded. Quite late at 

 night the anal segments hung down a little, but were soon erected 

 again. Next morning, and throughout the day, the first pair of 

 ventral prolegs and the second pair partly, sometimes Avholly, were 

 withdrawn from the twig, the hold of the larva being sustained then 

 by the third and fourth pairs, which brought the head down lower 

 than before on one side or other of the tail ; as night drew on all the 

 anterior legs were outspread to the utmost. In early morn of 

 September 5th it was in the same position as on the previous night, 

 though about noon the head was even still lower, and with the fore- 

 part of the body turned away a little on one side from the tail, and in 

 the course of the afternoon suddenly changed over to the opposite side ; 

 thus, with slight variation of detail, for the remainder of the day and 

 evening continued this wonderful exhibition of power and endurance. 

 At 10.35 p.m. the larva seemed to be getting restless, and continued 

 to swing itself partly round on the twig, still in the same circular 

 posture, and in a minute or two swung back again, and then com- 

 menced, gently at first, writhing backwards and downwards, soon with 

 increasing energy ; the anterior legs, having lately been folded 



