8 



Length of inflated specimens about 25 mm.: greatest diameter (at 

 the fourth and fifth segments) about 8 mm. These measurements 

 are probably greater than would be obtained from a living caterpillar. 



Cocoon. The cocoon is about 14 mm. in length and 10 mm. in 

 width, the smallest one found in a lot of over a hundred measuring 

 17 mm. by 8 mm. It is almost perfectly oval in outline though there 

 is sometimes a very slight constriction near one end marking the 

 line of attachment where the lid of the cocoon which separates 

 from the remainder when the moth escapes, joins the main portion. 

 The cocoon is whitish and brown, often so mingled as to present 

 a rather striking pattern and suggestive of certain oriental designs. 

 In time, as the cocoon weathers, the brown seems to fade, giving 

 a dirty grayish color to the structure. The lid in fresh cocoons 

 is nearly always quite uniformly brown in color. 



The cocoon is very tough and firm and is so solidly fastened to the 

 tree that it is frequently broken in the attempt to remove it. Its 

 location varies but the preferred position seems to be in or beside an 

 axil between a branch one-half or three-quarters of an inch in diame- 

 ter and a smaller twig. Occasionally one will be found attached to 

 the side of a twig near its tip where the diameter of the twig is con- 

 siderably less than that of the cocoon, and in a few cases they have 

 been found on the larger limbs, no attention in these cases being 

 paid to the presence of any small branches which might offer axillary 

 attachments. In one case a cocoon was discovered on the side of 

 an erect trunk which was at least four inches in diameter. 



The tendency to place the cocoons toward the tips on the smaller 

 branches is very strong, probably four-fifths being in this region. In 

 one case a fresh cocoon was found on the surface of a fresh winter 

 tent of the Brown-tail moth, and as the latter during the fall of 1906 

 did not complete their tents till about the tenth of September this 

 gives some indication as to the probable time of cocoon making. 



Within the cocoon the caterpillar assumes a short, stout form some- 

 what resembling a fullgrown Ox Warble though smaller. It loses its 

 colors, becoming yellowish white, and in this condition it hibernates, 

 transforming to a pupa sometime later than March of the following 

 spring. 



At emergence from the cocoon the lid is in some manner separated 

 from the rest of the cocoon, leaving a circular opening with smooth 

 even edges from one to three millimeters from the end. Through 



