548 PliOCEEDINGS OF THE AMERICAN ACADEMY. 



The first thoracic segment bears six tubercles, of which the lowest one 

 is a little larger than those of the row above, and the two median dorsal 

 ones are slightly smaller than those on each side. They are well devel- 

 oped, higher than in C. promethea, and nearly as in P. cynthia. The 

 tubercles of the three thoracic and 1st abdominal segments of the same 

 size and height, those of abdominal segments 2-7 a little smaller ; all 

 are about twice as long as thick ; the longer setae are fully twice as long 

 as the tubercles bearing them ; those on the 2d thoracic to 7th abdominal 

 segments are a little curved. Each dorsal tubercle bears 10-11 setae, 

 several arising some distance below the crown ; all are of unequal length 

 and thickness ; those on the mid-abdominal segments 7-8 in number. 

 The median dorsal tubercle on 8th abdominal segment is twice as thick 

 and considerably higher than those next to it. 



Suraual plate with two tubercles higher than broad ; this and seg- 

 ments 9 and 10 and all the legs, both thoracic and abdominal, are 

 brown-black. 



The body is black-brown ; all the segments are ivory white on the 

 posterior edge (the 1st and 2d thoracic less so than those behind), and 

 the front edge of the white transverse baud makes two scallops on each 

 side. Front edge of each segment dark, but the base of each tubercle is 

 surrounded by white. 



It moulted June 11, all the individuals casting their skins simultane- 

 ously, just as all were observed to hatch at the same or nearly the same 

 moment. 



Stage 11. Length 11-13 mm. The body is rather thick and the 

 thickness uniform. The head is not nearly so wide as the body. It is 

 peculiar in shape and color, rather deeply bilobed ; the surface soft 

 velvety black-brown, apex of the clypeus pale greenish ; between this 

 triangular spot and the eyes is a deeper yellow roundish spot, and behind 

 each group of ocelli is another long yellow mark; clypeus-anterior white, 

 labrura black. 



The body is armed with large, rather high tubercles, all nearly of the 

 same size, though those of the 2d and 3d thoracic segments are very 

 slightly larger than those on the abdominal ones, and that on the middle 

 of the 8th abdominal segment is nearly twice as thick as those on the 

 7th segment. 



On the prothoracic segment are four large high tubercles of equal size 

 and height, but slightly smaller than those on the 2d and 3d thoracic 

 segments, each with four stout spines and four smaller ones. All the 

 tubercles are fleshy and stand up like columns, and are about twice as 



