558 PROCEEDINGS OP THE AMERICAN ACADEMY. 



tubercle, at least a third longer. Those of the 1st abdominal segment a 

 little larger than those on segments 2-7. 



The median tubercle on the 8th abdominal segment double, and ap- 

 parently as large as the thoracic ones (this is covered by the loosened 

 skin of the previous stage). Legs as in the last stage, but the mid- 

 abdominal ones not so much black in extent at the end. Spiracles 

 black. The yellowish rings of the later stage are in this period faint. 



Stage next to the last. Length of body 70 mm. ; width of head 4 mm. 

 Head and body pea-green, as in the last stage. On the prothoracic seg- 

 ment the position of the primitive dorsal tubercles (seen in Stage III) is 

 indicated by minute setiferous warts. Dorsal tubercles on the 2d and 3d 

 thoracic segments a little (about one-fourth) larger than those on abdom- 

 inal segments 1-7; those on the latter-named segments slightly larger 

 than those on the intermediate segments, all bearing six radiating and a 

 central erect black seta; the tubercles are pale green (in the blown larv£e 

 examined they have turned yellowish like the dorsal ones). 



The median tubercle on the 8th abdominal segment of the same size as 

 those of the dorsal on the 2d thoracic segment ; it shows a slight bilateral 

 arrangement, there being six black setae on each side. 



Suranal plate and each of the anal legs with a pale bright red spot as 

 in the last stage. Spiracles black ; legs as described in the last stage. 



The larva in this stage differs from the full-grown caterpillar in the 

 larger tubercles, all of which are armed with well-developed spine-like 

 setae; in the nine (one more than in the last stage) yellow bands, there 

 being an additional one on the 2d thoracic segment, the bands or incom- 

 plete rings beginning at the infraspiracular row of tubercles and passing 

 over the back from one side to the other. 



Last stage. Length of body 110 mm.; width of head 4 Jj^ mm. Body 

 cylindrical. Head small rounded green, smooth, less than one-half as 

 wide as the prothoracic segment ; the clypeus narrowly edged with black, 

 and two diverging black lines extending from near the centre of the 

 vertex and passing down inside of the ocelli. 



Prothoracic segment with no traces of dorsal tubercles, but a green 

 pyriform tubercle in front of and a little below the spiracle, and a larger, 

 more prominent one still lower down, bearing six short setae, five around 

 the edge of the crown and one in the centre. 



Dorsal tubercles small pyriform, present on the 2d and 3d thoracic 

 segments; those on the 1st abdominal segment about a third smaller than 

 the thoracic ones, and with no setae. On abdominal segments 2-7 the 

 dorsal tubercles decrease in size to the 7th. The median tubercle on the 



