The Life Hlstorii of 3nlas favesrens. 51 



men of another (11 mm.), nine days after leaving the shell, 

 contained thirty-three ; while in another (8 mm.), seven 

 days after leaving the shell, there were only four or five 

 developed ova, and the abdomen could hardly have 

 contained more than fifteen or twenty. 



The following case of cannibalism occurred in the 

 present year : — 



Two larvse, "A" and " B,'' were due to leave their shells 

 about the same date, early in July, and both liad already 

 moulted. " A " left its shell first, and escaping unobserved 

 into the division of " B," entered the shell and attacked 

 and devoured the unfortunate occuiDant. The unconsumed 

 remains of " B " were afterwards cast back and left near 

 the orifice of the shell, and the larva "A" in due time 

 moulted, evacuating the shell thirty-five days after the 

 probf\We date of entering it. 



Among a number of shells examined, which have con- 

 tained larvEe, I have not noticed any clear case of parasitic 

 attack on the species. I am indebted to Mr. C. 0. Water- 

 house for his kind assistance in connection with the 

 subject of this paper. 



Explanation of Plate I. 



I'igure L Left antenna of larva, partially withdrawn. 



„ 2. Spiracle of larva, projecting from horny encaseiaent. 



. ,, 3. Part of intermediate leg of larva. 



,, 4. Female imago. 



Explanation of Plate II. 



Figure 1. Active form of larva ; part of head, showing antenupo 

 and mandibles (antennae extended). 



„ 2. Winter form of undeveloped larva ; part of head, showing 

 antennas and mandibles. 



„ 3. Winter form of full-fed larva ; part of head, showing 

 antennae and mandibles. 



,, la. Active form of larva ; last segment. 



„ 2a. Winter form of undeveloped larva ; last segment, 



„ 3a. ,, ,, ,, full-fed larva ; last segment, 



