CERURA VINULA. 149 



of operations, working backwards until it had quite 

 doubled on itself, the head and tail being at one end, 

 and the middle of the body at the other end ; the 

 cocoon inside being thus just half the length of the 

 larva. This widening did not take so long as the first 

 portion, and in making it the larva would sometimes 

 burst the earlier spinning. When the whole body was 

 thus covered the larva proceeded to fill up the open- 

 ings in its spinning, partly by more bits of wood 

 gnawed from beneath, and partly by smearing its 

 sticky silk, which, as far as I could see, came entirely 

 from the mouth, or from near the mouth. One larva 

 had completed a perfect coating in four hours, but it was 

 still soft and yielding; in nine hours from the com- 

 mencement the cocoon was tough and firm, though 

 not very hard ; in four and twenty hours it had become 

 quite hard. Thus rather more than half of the cocoon 

 is an oval pit gnawed out of the wood, and the outer 

 side is a somewhat swelling oval formed of chips and 

 silk ; the whole of the interior is lined with this silk, 

 looking as if varnished, especially at the ends, although 

 the surface is not very smooth ; the general measure- 

 ment outside is about 40 mm. in length and 25 mm. in 

 width. The pupa is short and stout in figure, full 

 30 mm. in length, and 13 mm. across at the widest 

 part of the abdomen ; the head a little prominent, the 

 eyes prominent, the antenna-cases distinct though not 

 prominent, the waist a little sunk at the back and sides, 

 the abdomen swelling out, and tapering in a curve to 

 the rounded tail, which has no spike, but the whole of 

 its surface is set with several rough points, and it has 

 a slight central depression ; the divisions of the abdo- 

 minal segments are well cut; the skin generally is 

 rough, but the segmental folds smooth ; the colour 

 dark brown with a tinge of purple-red. 



I may add that once I had an example two winters 

 in the pupa state ; most of the brood appeared as moths 

 in the May of the year following that in which they 

 were hatched, but this individual did not emerge 



