50 Mr. L. R. Crawsha}^ 07i 



Another shell contained the remains of a male puj)a 

 which had probably failed to emerge in tlie previous 

 spring. 



The shells containing these six males were : — 



Two of them HcliceUa virgata, Da Costa ; 8 and 9 mm. 

 in diameter respectively. 



Four of them HcliceUa ccvperata, Montagu, 7, 7, 7, and 

 8 mm. in diameter respectively. 



Another shell found at the same time, containing a 

 male pupa skin, was that of HcliceUa caperata, 6 mm. in 

 diameter. 



The following table shows the greatest diameter of 

 thirty-seven winter shells (all naturally occupied by larvaa), 

 and the state of the insect after hibernation : — 



2 shells of 4 mm. in diam. produced 2 undeveloped lai'v.T. 



5 „ 6 „ „ „ 4 „ „ and 1 ^. 



) V ^ )5 )5 M '^ O • 



5 5) 4 )) )5 5) -^ CJ • 



) !) ^ r !) J) ^ c5 • 



) 57 •^ J) 75 )) <^ + • 



In other words, all full-fed larvte occupying shells of 

 6-9 mm., and averaging 7-o- mm., were males, and all those 

 occupying shells over 9 mm. were females ; which result 

 might, in fact, be expected approximately, considering 

 that the male imago never perhaps attains the minimum 

 length of the female. 



The females probably outnumber the males very consider- 

 ably, while the male larva must be sought for in shells of a 

 small size only. But, apart from these considerations, the 

 male seems, for some reason, to be more difficult to rear 

 than the female — possibly owing to the fact that it is more 

 likely to complete its limited growth early in the year, 

 and so to be subject to a longer period of exposure to the 

 exigencies of weather. 



The number of eggs laid by the female may be as many 

 as three hundred, or even more ; but the female, which 

 is little more than an egg-magazine, varies in size to an 

 extraordinary degree, and the number of eggs must vary 

 greatly in proportion. In a female of 19 mm. I found 

 two hundred and sixty-seven, but in smaller examples 

 the numbers were far short of this. The two that laid 

 (presumably 10 mm. and 13 mm. respectively) cannot 

 either of them have laid more than about forty ; the abdo- 



