562 PROCEEDINGS OF THE AMERICAN ACADEMY. 



are black, with the exception of the yellow dorsal portion of the 2d 

 thoracic and abdominal segments 1-7, and the under side of the body, 

 including the mid-abdominal legs. He tells me that other specimens 

 have as much black pigment on the body, but that the dorsal tubercles 

 on the 2d and 3d thoracic and 8th abdominal segments are as blue as in 

 the light-colored caterpillars. 



The larva I had in Providence moulted for the second time about 

 June 4 or 5. 



Stage III. Length 20 mm. The head is now wholly pea-green. 

 The two median prothoracic, and the two dorsal tubercles on the 3d 

 thoracic segment, and those of the lateral row are turquoise-blue, 

 but the two dorsal tubercles on the 2d thoracic segment are greenish. 

 The two 3d thoracic dorsal tubercles are thicker than those on the 

 2d thoracic segment, and about twice as thick as those on the 1st ab- 

 dominal segment. The medio-dorsal tubercle on the 8th abdominal 

 segment is much thicker than those near it. The proportionate size of 

 all the dorsal tubercles is as in the previous stage. Spiracles pale 

 brown, not conspicuous. 



The black dots low down below the lateral ridge are now nearly 

 obsolete. 



Anal legs with no external black spots, and entirely green. The 

 thoracic legs green, with a few black spots. 



Mr. Joutel, who had more larvae under inspection than I, says, " All 

 the larvae are gradually losing the black pigment; the dark ones have 

 only the base of the dorsal tubercles on the 3d thoracic and 8th ab- 

 dominal segments black, with the tips blue ; also the lower half of the 

 face is black." 



It was found to have moulted for the third time June 23. 



Stage IV. Length 23 mm. (when underfed) -42 mm. The body 

 is now thicker at the 3d thoracic segment, and in fact somewhat so 

 throughout, while the tubercles are smaller, and all but those on the 

 back of the 3d thoracic and 8th abdominal segments are decidedly 

 reduced in size. The skin is now covered with minute rounded warts or 

 granulations. The head and body are pale greenish straw-yellow (more 

 yellow than green). The tubercles are of the same hue as in Stage III. 

 The six tubercles on the front edge of the 1st thoracic segment are 

 turquoise-blue. 



The two dorsal ones on the 3d thoracic segment are turquoise-blue. 

 The medio-dorsal one on the 8th abdominal segment, and the four on the 

 side of the 9th segment are turquoise-blue ; but the_two dorsal ones are 



