1883.1 75 



the segmental division in their downward slant, but cross it, and are 

 thence continued narrowly and obscurely below on the segment 

 following. 



After the third moult, their growth was quick, two days' feeding 

 increased the length from 1 inch 3 lines to 1 inch 4i lines, with greater 

 stoutness also in proportion, the thoracic segments decidedly tapering 

 to the small head ; the relative colouring much as before, paler whitish- 

 yellow-green on the back, with deeper green dorsal line, black at top of 

 the prolonged hump, which is now seen to be slightly divided into two 

 blunt points ; the yellowish side-stripes margined both above and 

 below witli deep green, and the sides below them of still deeper green, 

 irrorated with fine black dots, except just where the attenuated 

 continuations of the side-stripes can be traced ; the bases of the 

 anterior legs black. 



After the fourth and last moult, their docile behaviour continued 

 to be remarkable, as they showed no disinclination to be handled, but 

 grew quite lethargic, often sleeping side by side contentedly like so 

 many fat pigs ; but when awake, they made good use of their time, 

 consuming a great quantity of birch, and their growth was com- 

 mensurate, for, by 26th of June, some were 2 inches 3 lines in length, 

 others, later, as much as 2 inches 7 lines, and bulky in proportion ; the 

 head very small, with the thoracic segments rapidly tapering to it, and 

 retractile as in Chwrocampa, though to a less extent. The middle of the 

 body is rather the thickest, and the twelfth segment, with its humped 

 elevation bluntly pointed and slightly divided, slopes backward at 

 an angle to the anal flap ; the ventral and anal legs are developed 

 much after the fashion of Smerinthus ; the other segments are lightly 

 sub-divided into four nearly equal portions by slight wrinkles, the 

 segmental divisions more strongly defined, especially on the belly ; the 

 skin is soft and smooth, glistening on the head, which is green, and has 

 two whitish or yellowish-white stripes beginning on either side, and 

 continuing to the end of the thoracic segments, the uppermost as a 

 sub-dorsal, and the lower as an inflated spiracular stripe ; the back is 

 pale opaque green, slightly inclining to yellowish in the lightest and to 

 bluish in the deepest portions and in the dorsal line ; below the yellow 

 stripes, which are bordered above with green, the ground colour of the 

 sides is of a yery deep and rich full green, increased in depth by the 

 close irroration of minute black dots, and relieved by the white oval 

 spiracles delicately outlined with black ; in front of these comes a thin 

 line of quiet ochreous-greenish, as though a continuation of the slanting 

 stripe from the preceding segment, more noticeable on approaching 



G 2 



