52 Dr. T. A. Chapman on 



his crawled away and spun white webs in the corner of his 

 cages,and then dried up. The proportion going over a second 

 year was probably abnormal, owing to poor rations and a 

 colder climate, but it must be to some extent a regular 

 habit, or it would not occur at all. 



Larva of H. corticalis. 



The larva is of a dull greyish-brown, as the result of a yellowish 

 ground colour, and fine marbled markings or spots, that vary from 

 reddish to blackish-brown. These minute spots are aggregated more 

 closely, and are of darker colour in places, so as to produce the appear- 

 ance of a narrow dark dorsal line, and a broader one j ust outside the 

 trapezoidal tubercles. This one is darker and wider in the prothoracic 

 plate. A suffused and indefinite line above, and a more definite nar- 

 row one below the spiracles. The supra-spiracular marking is to 

 some extent in diagonal detached pieces, like the lateral stripes in 

 Sphinx. The head is mottled in the same colours as the body. 



The tubercles are darker, but not quite black ; they each carry a 

 light-coloured bristle, about 0"8 m.m. in length ; these are slightly 

 porrected. The second tubercles on 3rd and 4th segments (2 and 3 

 thoracic) have partial (that on 4th nearly complete) dark raised corneous 

 circles round them, and the supra-sj)iracular tubercle (III.) of the 

 12th segment (8th abdominal) has a more delicate, but very com- 

 plete similar ring, precisely as in most Phycid larvae. The spiracles 

 are raised on conical projections, faintly paler than the general 

 surface, but inconspicuous. The tubercles below the spiracles are 

 on definite smooth areas or plates, that look slightly sunk below the 

 general surface. They are, first, on one plate below the spiracle, 

 two tubercles : one, the lower, immediately below the spiracle, the 

 upper slightly in front of it ; the hairs on these tuljercles rather 

 short. Rather lower and at posterior border of tlie segment a soli- 

 tary tubercle with long hair. Lower, and at outer and front side of 

 foreleg (on 7-10) a large plate, carrying three short hairs, in one 

 line, the first just above, the third in front of foreleg ; lowest of all, 

 a small tubercle near the middle line. IV. and V. are on one plate, 

 VII. VIII. and IX. on another. The solitary tubercles I. II. Ill, 

 VI. and X. all have the same structure. The circle surrounding the 

 hair is at the summit of a conical projection, or pyramid, with 

 wrinkled sides, like mountain slopes furrowed by ravines : a not 

 uncommon form of tubercle in Pyralids. 



The structure of tubercle IV. in 8th abdominal segment is as though 

 the circle surrounding the hair, instead of at once forming the slope, 



