30 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 95 



On the dorsal surface the short bristles with enlarged ends are more 

 numerous, and lighter in color. These also extend down the sides to 

 below the spiracles. Below these along the inferolateral border of the 

 segments are numerous hairs of moderate length. 



The prolegs bear numerous hairs of moderate length. 



The head is almost black, and is unmarked. The first pair of true 

 legs is darker than the others. 



The maximum size for this stage is 12 to 13 mm in length by 2."] mm 

 in width. 



FOURTH-STAGE CATERPILLAR 



Plate 6, fig. 34 ; text fig. G, p. 29 



The head capsule is 3 mm wide at its widest part. 



The total length of freshly molted caterpillars just entering this 

 stage is 12 to 13 mm. 



The head is as in the stage preceding, but more densely hairy, the 

 hairs cur^ang downward and being longest in the vicinity of the 

 mouth parts. 



The thoracic shield bears numerous scattered hairs. 



Beyond the abruptly truncated end of the thoracic shield, extending 

 downward to in front of the upper portion of the large oval spiracle, 

 is a triangular plate, more or less definite, with the downward pointing 

 apex very broadly rounded, representing the detached end of the 

 shield, from which it is separated by a rather broad channel. 



The dorsal surface is thickly beset with short, fine hairs, more or 

 less of the ordinary form, which become longer and finer along the 

 lower lateral margins of the segments, and longer and stouter at the 

 end of the body. 



The prolegs bear numerous fine hairs which become thickly crowded 

 and curved downward toward the foot. 



All of the circular indurated spots described for the last (fifth) 

 stage are present. 



The color is as in the following stage, except that the head is 

 somewhat darker and the large spots, now appearing for the first time, 

 are vague and ill-defined and shade imperceptibly into the surrounding 

 color. 



When the first thoracic segment is swollen preparatory to molting, 

 a broad, elongated deep chrome spot appears extending backward and 

 diagonally outward from under the necklike posterior extension of the 

 head capsule on either side at the dorsolateral margin. 



The maximum size of this stage is about 22 mm long by 4.5 mm 

 wide. 



