154 THE ENTOMOLOGIST. 



a more tubular form, tapering towards the posterior aperture, 

 which is enlarged from time to time. The outside is covered 

 with numerous fragmentary leaves and twigs of various sizes 

 placed longitudinally on the case, and frequently there are green 

 pieces near the anterior aperture, which the larva has recently 

 selected and joined on. The interior is lined with soft smooth 

 silk of a light brown colour, the thickness of the whole fabric 

 being about the same as that of an ordinary kid-glove, and so 

 strong that it is impossible to tear it, or indeed to cut it, except 

 with sharp instruments. The size of the case when the cater- 

 pillar is mature varies considerably, ranging from twenty-five to 

 thirty lines or more in length, and about three in diameter, the 

 widest portion being a little behind the anterior aperture. 



During the day the larva spins a loop of very strong silk over 

 a twig, the ends being joined to the upper edges of the case on 

 each side ; in this way it hangs suspended, the caterpillar lying 

 snugly within. I have often known a larva to remain thus for 

 over three weeks without moving, and afterwards resume feeding 

 as before ; this probably occurs while the inmate is engaged in 

 changing his skin, the cast-skin being most likely ejected 

 through the posterior aperture of the case. 



At night the larvae may be seen busily engaged : they project 

 the head and first four segments of the body beyond the case, 

 and walk about with considerable rapidity, often lowering them- 

 selves by means of silken threads ; the only locomotive organs 

 are of course their strong thoracic legs, which appear to easily fulfil 

 their double function of moving both larva and case. If disturbed 

 these insects at once retreat into their cases, closing the anterior 

 aperture with a silken cord, which is kept in readiness for the 

 purpose, and pulled from the inside by the retreating larva. 

 This operation is most rapidly performed, as the upper edges of 

 the case are flexible, and thus fold closely together, completely 

 obstructing the entrance. 



From the case I will now turn to the description of its 

 inhabitant. The chief peculiarities of the young larvae have 

 been noted above ; what follows consequently refers to the full- 

 grown caterpillar. The head is moderate in size, of a light 

 yellowish colour, covered with a number of minute black specks ; 

 the first three segments are white, very smooth and shining, 

 with a dark brown dorsal line and a large lunate spot, similar in 



