184 GRAPTA O-ALBUM. 



narrowing towards the tail ; a pair of dark dashes on 

 the under side of the thorax, and a dark diamond 

 pattern down the abdomen ; the spike outlined in pink 

 and brown lines. The pupa received from Mrs. 

 Hutchinson was darker than the others, but seemed 

 to have been injured. (J. H., 31, 10, 85.) 



Thecla Betulji. 

 Plate XII, fig. 4. 



This species is not at all so common in the neigh- 

 bourhood of Exeter as Th. Quercus, and although I 

 have for several years taken the larva in May and June, 

 yet all the examples I have seen if put together would 

 nob equal the numbers of Quercus taken in a single 

 season of average productiveness ; its food-plant, the 

 blackthorn (Prunus spinosa), does not ordinarily grow 

 except in hedges, and no doubt the clipping and trim- 

 ming it there receives keeps down the number of larvae 

 that come to perfection. This year (1885) I could 

 not find an example, but Mr. Gr. C. Bignell worked 

 very hard for me in the neighbourhood of Plymouth, 

 and at last obtained one larva, which reached me on 

 June 12th; it was then not quite 9 mm. long, 3 mm. 

 wide, and its colouring not very different from the 

 final appearance, but the skin was more glossy though 

 covered with fine pubescence. On June 18th it 

 moulted; the cast skin was not eaten. After this it 

 seemed to thrive for a time, and grew larger, but I do 

 not think it attained perfect growth, and at last it began 

 to shrink again, and died about the middle of July. 



On June 29th, whilst it was still thriving, I described 

 it as follows : length about 14 mm., greatest width 4J 

 mm., namely, at the fifth segment, where it also 

 measured 4 mm. in depth from the dorsal ridge to the 

 belly, at that segment a transverse section would be 

 triangular ; the belly flat, through segments 5 to 13 the 

 sides slope from the dorsal ridge down to the subspira- 



