72 PROCEEDINGS OF THE AMERICAN ACADEMY 



than before, and whiter yellow ; the head with more white, especially 

 on the vertex, and the white stripe across the middle is rather wider. 

 The 2d and 3d thoracic, 1st, 8th, and 9th abdominal dorsal tubercles 

 are not distinctly larger than the others, and all are paler. The black 

 stripes are nearly as before, but perhaps not quite so heavy. The 

 suranal plate is not so black as before, but with two black spots ; and 

 on the side of the anal plate is a black elongated patch. 



Stage IV. — Length 34-35 mm. The characters of the fully 

 grown larva are now nearly attained. The head is large, three 

 fourths as wide as the body, pale lemon-greenish, with six black dots, 

 two below, and one above. The two dorsal prothoracic tubercles 

 yellowish ; the lateral ones black. The two dorsal tubercles on the 

 2d and 3d thoracic segments are now high, large, and with ob- 

 solete spines, red, with a black base or ring (Miss Soule says, " black 

 at base, ringed with yellow, orange at tips, smooth "). The single one 

 on the 8th abdominal segment is ringed with black at the base, and 

 beyond yellow ; it is slightly smaller than those on the thoracic seg- 

 ments. All the other dorsal as well as lateral tubercles are now re- 

 duced to low small black rudimentary tubercles. In this stage it 

 differs from that of C. promethea of the same stage in the much 

 shorter black tubercles on the 2d to 7th abdominal segments ; and in 

 the dorsal tubercles on the 2d and 3d thoracic segments being reddish, 

 instead of yellowish. The curved horseshoe-shaped black line on the 

 side of the anal legs is the same as in 0. promethea. The "yellow 

 stigmatal ridge " noticed by Miss Soule is shown in Bridgham's 

 figure. 



Full-groton Larva. — Length 68 mm. On comparing a blown 

 specimen of G. angulifera with one of C. promethea the former differs 

 in the following particulars. The head is slightly larger, without the 

 two black dots in front and the lateral dot, and without the broad 

 black stripe extending in O. ])romethea from each side of the base of 

 the labrum upward, and ending on the side of the head below the 

 lateral dot. The four dorsal black spots on the prothoracic segment 

 are wanting in (J. angulifera, and the short lateral tubercles are not 

 colored black as in (7. promethea, while the tubercles themselves are 

 much smaller and less prominent. The four dorsal tubercles (two on 

 the 2d and two on the 3d thoracic segment) are decidedly smaller 

 and slenderer than in G. promethea ; the tips are black where those of 

 G. promethea are yellow, and the black ring around the base is nar- 

 rower than in G. promethea. The two lateral small black tubercles on 

 each of these segments are wanting, and all traces of them have nearly 



