SPHINX CHERSIS 153 



The third molt came four days later. The only 

 changes were dots, instead of granules, on the body, 

 and green all over the horn, with black spines on its 

 front. The horn was held nearly horizontal. 



Six days later the fourth molt took place. The head 

 was almost triangular, slightly bilobed at the apex, and 

 green, with faint white dots and yellow face-lines. The 

 thoracic segments were bright green, rough withwiiite 

 granules. The abdominal segments were bright green 

 on the sides and venter, almost white on the. dorsum, 

 with white dots. The obliques were yellow-white, 

 edged above with deep blue-green. The horn was long, 

 stout, rough, curving backward, sometimes green, some- 

 times bluish, sometimes bluish with a pink tip, occa- 

 sionally pinkish ; and two or three had the horns green, 

 with blue at the base in front. The legs were reddish, 

 the props green dotted with white, and the anal plate 

 was very yellow-green, edged with still yellower. The 

 spiracles were dark, surrounded by a yellowish line, 

 and conspicuous. 



As they grew older the thoracic segments were 

 smoother, until at last the granules were hardly more 

 than dots. The caterpillars ate ravenously after this 

 molt, and grew to a length of four inches. They ate 

 for four days, then grew moist and lay on the tin, pu- 

 pating four days later. Usually they need no earth in 

 the tin, but one or two exuded so much fluid that we 

 put them on a little earth. 



Unlike all other sphingid larvae we have watched in 

 pupation, chersis rests on the venter through all the 

 quiet time of preparation for casting the larva-skin. 

 The first sign of readiness to cast the skin was a some- 



