Packard.] J-^-' [March 17, 



ment, the outer ones are half as long as the inner or dorsal ones, wliich 

 are 4.5 mm. in length ; those of the third thoracic segment are of the 

 same size as those on the second. There are four similar but much 

 smaller dorsal and subdorsal horns on each of the abdominal segments 

 (but they are shorter and more regularly conical than in Stage IV"), those 

 on each segment being of the same size, the two dorsal ones being almost 

 three times as large as the subdorsal ones, each dorsal one bearing three 

 terminal spines. Those on the thoracic segments are tuberculated. end- 

 ing in a forli. On the eighth abdominal segment is a median dorsal horn, 

 now shorter in proportion than in Stage IV, small and short, length 2 mm., 

 nearly twice as large as the other dorsal ones in front, tuberculated and 

 slightly forked at the end, but not so regularly forked as in Stage If. 

 There is a minute median one on the ninth segment, and two minute lat- 

 eral ones on each side of the segment. Tlie spiracles are very large and 

 conspicuous, yellow with an outer ring of very dark green, which is 

 edged on each side with paler green ; those on the prothoracic segment 

 are without the deep-green outer ring. The suranal plate is regularly 

 triangular, gamboge-yellow, with a swollen, rough, coarseh^ granulated 

 edge, within which the surfticeis black, with yellow coarse granulations. 

 A similar narrow triangular plate on the anal legs. The middle abdom- 

 inal legs dark pea-green, with a deep ochre-yellow transverse band above 

 the black planta. 



For a careful description of the egg and the larva in its first four stages 

 see Dr. J. A. Lintner's Ent. Contr., ii, 150. His larvaj molted four limes, 

 and he thought from the small size of the specimens after the fourtli molt, 

 that there might be a fifth one. 



The fiflli and last stage differs from Stage IV in the shorter dorsal horns 

 and "caudal" horn; the tubercles on the sides of the body also being 

 decidedly shorter, while the anal legs are larger, with a wider, dark, gran- 

 ulated area on the outside. The body is also thicker and heavier, while 

 the head is paler. 



It is noticeable that in this form, as in the Attacin*, there is a great 

 increase from one stage to another in the size or bulk of tlie body, while 

 the head does not increase in a corresponding ratio. 



SUMMARY OF THE CHIEF ONTOGENETIC FEATURES. 



A. Congenital Characters. 



1. In Stage I there are three pairs of very long dorsal deeply forked 

 thoracic horns, nearly half as long as the body. 



2. A similar median spine on the eighth abdominal segment, with one 

 half as long on the ninth. 



3. The abdominal segments are transversely banded with black. 



4. The lateral spines on the abdominal segments bifid and nearly as large 

 as the subslraple dorsal ones. 



5. Body pale chestnut brown ; head light reddish. 



