106 THE CANADIAN ENTOMOLOGIST. 



their long narrow galleries, while the teeth assist in backward motion in 

 them. The mature larvae obtained in May differ but slightly from these, 

 except that they are then .7 of an inch long and the pink stripes and 

 marks are brownish. The fourth, fifth and sixth segments are smaller 

 than those preceding or following them. They are quite active, moving 

 up and down their burrows rapidly. 



By the middle of May the caterpillar has worked its way back to the 

 place of entrance in autumn, enlarging its way to accommodate its 

 increased size, and after loosely stopping the upper part with a few chips, 

 retires and changes to the pupa. It is then .6 of an inch in length, 

 slender, cylindrical. Color white, except the oblique disc or plate 

 terminating the head, which is made dark by many teeth-like .elevations on 

 its surface. The abdominal segments are clothed with hairs, and the last 

 four segments have each a transverse row of teeth on the dorsal part, 

 reminding one of a Tortrix or Cossus pupa. The conical tip of the 

 abdomen has many teeth ; these teeth, together with the roughness upon 

 the head, enable the pupa to worm its way up and down the burrow with 

 readiness. When removed from the stem to the table it travels about, 

 rolling and worming its way very much as do the pupa; of certain stem- 

 boring beetles. The wing and limb covers are free for a considerable 

 distance from their tips. 



The moth appears from the 1st to the 15th of July; the largest 

 measured expanded 1.2 inches. 



This moth has a peculiarly interesting history, increasing much the 

 known diversity of form and habits of the preparatory forms of the 

 Pterophoridae. 



Concerning the smaller one which feeds upon the leaves, I will say 

 that the larva and its habits are too imperfectly known to me to detail ; 

 that the pupa is found during the first days of July fastened to the under 

 side of the leaf parallel to the mid-rib. Its appearance is quite like that 

 of the pupa of the best known forms of the group. 



ENTOMOLOGICAL NOTES. 



I find Dorytomus mucidus Say running on and flying about Cottonwood 

 trees early in April and again in August. In October it is found under 

 dead bark of trees, in winter quarters. Common. 



