APLBOTA OCCULTA. 41 



Polygonum, then on birch and sallow, with bilberry, 

 afterwards dock and bramble, finally on dock, sallow 

 buds and catkins. 



The egg of A. occulta is globular in shape, a little 

 depressed on the summit, and rather flattened beneath ; 

 the shell ribbed and finely reticulated, of a pale straw 

 colour when first laid, afterwards becoming a pinkish- 

 drab, and at last a dark lead colour. 



The newly-hatched larva is of a pellucid whitish- 

 green, with minute black dots ; on the third day be- 

 coming greener on the back, yellow on the sides, and 

 head pale brown ; after moulting twice it is yellowish- 

 grey on the back and belly, dark greyish-brown on the 

 sides, the dorsal and subdorsal lines dirty whitish, the 

 latter edged above with black near the end of each 

 segment to halfway along the next ; the pale yellowish- 

 white subspiracular stripe, so characteristic of this 

 larva, now first appears with a black line above it. On 

 becoming five-eighths of an inch long it is so dark as 

 to appear almost black, though in reality the sides are 

 darker than the back, especially towards the spiracles, 

 where the blackest part being in contrast with the pale 

 yellowish-white stripe below, makes it appear very 

 brilliant ; the black subdorsal streaks have now be- 

 come thickened into wedge-shapes, broadest at the 

 twelfth segment, where their bases are only separated 

 by the thin and much interrupted yellowish-grey dorsal 

 line. At this stage in their captivity it was that the 

 precocious individuals began rapidly to increase in 

 size, and attain full growth in autumn, some of them 

 keeping almost black to the last, others showing a 

 mouse-coloured ground-tint, more or less, between the 

 black markings ; in these lighter examples the black 

 marks were greatly reduced, in two instances to the 

 merest rudiments. 



The full-grown larva measures nearly two inches in 

 length, is stout in proportion, cylindrical in figure, 

 though tapering a little at the thoracic segments to the 

 head, which is the smallest segment ; the thirteenth. 



