40 3[r. L. R. Crawshay on 



apes — on the inner margin a two-jointed supplementary 

 process terminated by a long seta,, and on the outer margin 

 a smaller colourless process. The thoracic segments have 

 a reddish-brown corneous covering above — marked with 

 dark patches — with a few hairs. On each of the abdominal 

 seoqnents to the penultimate one the soft white body of 

 the larva is protected above by a dark brown dorsal shield, 

 sparsely hairy, bearing a bristU" process on eacli margin, 

 and bv a pair of similar processes outside these, arising 

 from the sides. The last segment has a single pair of 

 laro^er bristlv processes extending behind, with a spine at 

 the apex of each, completing a covering which doubtless 

 (Toes far to protect the larva from attack during its occu- 

 pation of the snail-shell. The spiracles (Plate I, fig. 2) 

 lie in an uncovered space between the dorsal shields and 

 lateral processes, and j^roject from small horny encase- 

 ments which lie along the surface of the segments. A 

 fleshv nipple on the under-side of the last segment aids 

 the progression of the larva, and enables it to cling firmly 

 to the surface of the snail-shell. It moves lapidly about 

 the outside of the shell, aided also by a pair of small 

 colourless puhdlli, attached by slender stalks to the base 

 of the tarsal claw (Plate I, fig. 3). 



The young larva, which is hatched about the middle 

 of July, feeds till September, and then hibernates in the 

 shell it has last occupied, attaining only a small size in 

 the first year. This shell is evacuated in the following 

 spring, and after this the larva may continue feeding at 

 regular intervals till September. But owing to the exist- 

 ence of a distinct, inactive form for hibernation, and the 

 fact that this may be assumed at any time of the summer, 

 it is equally liable to pass nearly the whole of the year in 

 a dormant state in the shell. Doubtless the larva often 

 becomes full-fed in the year after hatching, but it probably 

 more often feeds for a third summer. The full-fed larva 

 then changes into a second hibernating form, pupating 

 in the folloTi\-ing spring, shortly before the appearance of 

 the imago in May or June of the tiiird or fourth year, 

 as the case may be. 



The snails which chiefly constitute its food in the 

 locality referred to are Helic^Ha itala, Linne ; HeliceUa 

 virgata, Da Costa ; and HeliceUa caperata, Montagu ; but 

 the larva has shown the same readiness to attack any 

 other species that I have hitherto tried, including : — 



