68 PROCEEDINGS OF THE AMERICAN ACADEMY 



Figure 4 (Plate I.) represents a dorsal view of the last four abdom- 

 inal segments (VII.-X.) with the medio-dorsal tubercle (d') on the 

 eighth uromere (VIII.), bearing ten seta?, two of them arising one on 

 each side of the median line ; a, a seta from one of the dorsal tubercles 

 on the 9th segment; b, one from the 7th segment showing the medul- 

 lary fluid supposed to be the poisonous secretion, though there is no 

 secretory cell visible at the origin of the spine ; the spine is dark 

 and rather opaque. 



Stage III. — (Described from an alcoholic specimen in the author's 

 collection.) Length 15 mm.; width of head 2 mm. The head is 

 marked in general as before, but the hairs are smaller and less numer- 

 ous. The sinuous ivhite band in front is much wider than before, 

 being in front fully three times as wide as the black line connecting the 

 eyes ; the baud being narrower on the sides above the eyes. The 

 head is much narrower than the body, which is now stout and thick. 

 The two transverse black bands or rings on each of the thoracic and ab- 

 dominal segments have now disappeared, only faint traces of them being 

 left here and there, the most persistent traces being a minute linear 

 black spot situated on the side behind the spiracles. The protho- 

 racic tubercles are black, and about half as long and large as the 2d 

 and 3d thoracic dorsal ones, which are whitish, with a black ring at 

 base ; the lateral ones being black-brown. All the dorsal abdominal 

 tubercles are but a little smaller than the thoracic ones, and all, both 

 dorsal and lateral, are black-brown, except the single large dorsal tu- 

 bercle on the 8th segment, which is now very large and fully twice 

 as thick as the largest dorsal ones elsewhere, if not more ; it has 

 four spines on each side, and two central ones. In all the tubercles 

 the spines are now short, and no longer than the thickness of the tuber- 

 cles bearing them. The black curved line on the side of the anal legs 

 is now more curved than before. 



Stage IV. — (Described from Mi - . Bridgham's colored sketch.) 

 Length 20 mm. The head is now yellow, with two black dots in front, 

 and a narrow black transverse line connecting the eyes and antennae : 

 the head is about two thirds as wide as the body, which is now whit- 

 ish. The tubercles on the prothoracic segment are black, and of the 

 same size as those on the abdominal segments, the latter [dorsal ones) 

 being now about one half as long and large as those on the 2d and 3d 

 thoracic segments ; the single median dorsal one on the 8th segment 

 being a little thicker, and colored sulphur-yellow (Riley), like those on 

 the 2d and 3d thoracic segments. 



The curved black line is slenderer than in Stage III. All the legs, 

 both thoracic and abdominal, are pale yellowish. 



