138 THE ENTOMOLOGIST. 



aperture : at this season of the year these larvae may often be 

 seen crawling about on the surface of the bark, or making a 

 new hole for again entering into the interior : in the January 

 following they can only be found by cutting deep into the 

 tree : they then eat voraciously, as may be known by the 

 quantity of frass which may then be observed on any pro- 

 jection of the tnuik that happens to have caught it in falling, 

 or on the ground at the foot of the tree : a non-entomological 

 observer may well suppose this to be sawdust, which by some 

 inexplicable means has got lodged in all manner of impos- 

 sible, or at any rate unlikely, places, but, so far as my expe- 

 rience goes, rarely exceeding a height of ten feet from the 

 ground, even in the largest trees : at this period the larva 

 generally eats upwards ; a little later it returns, and widens 

 its burrow here and there ; and eventually eats its way to the 

 outer world, leaving only the thin outer cuticle of the bark, 

 and then, reascending its old burrow, about April it s])ins a 

 strong white silken cocoon, and makes up therein. [The full- 

 fed larva is about an inch in length, nearly cylindrical, but 

 having a manifest lateral skinfold ; the head is corneous, gla- 

 brous, porrected, and very manifestly narrower than the Snd 

 segment, into which it is sometimes partially received ; the 

 2nd segment has a glabrous dorsal plate ; both the head and 

 body emit a few scattered bristles. Colour of the head and 

 2nd segment testaceous-brown ; of the body creamy white, 

 the spiracles dark brown, but small and inconspicuous : after 

 completing its cocoon it remains during the winter in a state 

 of repose, neither changing to a pupa nor attempting to make 

 its escape, but in May it becomes a pupa, which at first is 

 of a creamy white colour, but by degrees becomes testaceous- 

 brown : the case covering the head is produced into a frontal 

 point; the eyes are very prominent; the cases of the wings 

 are short ; the cases covering the middle and hind legs are 

 free at the extremities, those of the hind legs exceeding the 

 wing-cases in length ; the dorsal area of the abdomen has two 

 transverse series of scabrous points on the 1st, 2nd, 3rd and 

 4th segments ; the first of these two series has larger, longer 

 and more pointed teelh or serratures than the second : neither 

 of the series is continued on the ventral surface of the seg- 

 ment: the object of this armature is to enable the pupa by a 

 wriggling movement to make its way, after it has escaped 



