82 PROCEEDINGS OF THE AMERICAN ACADEMY 



is a large pale yellowish amber tubercle.* In some individuals all the 

 tubercles on the body are amber-yellow. 



The thoracic and abdominal legs are pale greenish, with no mark- 

 ings. The thoracic feet bear near the ungues the usual three tenant 

 hairs, which are long-lanceolate, and moderately broad. The number 

 of crotchets on the abdominal feet is twenty-four, larger by eight than 

 in the other Attacidae observed. 



June 17, they had become larger, fuller, and from 9 to 10 mm. in 

 length. The body is of a beautiful soft glaucous green, the tubercles 

 yellowish, those on the prothoracic segment tinged with reddish ; the 

 black-brown slashes on the sides of the body are still present, but 

 narrower. They are voracious feeders. 



June 19, at Providence. (Like Mr. Bridgham's second drawing, 

 Stage II.) I have not seen them cast their skins, though they must 

 have done so. They are now 1 1 mm. long. They still retain the 

 black slashes. All the tubercles are yellowish ; the body being of a 

 beautiful glaucous green. In some individuals the lateral prothoracic 

 tubercles are reddish. 



Figure 8 (Plate III.). Dorsal view of the 8th to 10th abdominal 

 segments of the larva in Stage I., showing the double tubercle (d') on 

 the 8th segment (VIII.), and the two separate dorsal tubercles (d) on 

 the 9th segment (IX.), with the two subdorsal tubercles of this seg- 

 ment (sd), together with the suranal plate (X.) and its armature. 



Figure 9. A view of the double dorsal tubercle (d') of the same 

 stage, showing the median line of union of what in embryonic life were 

 probably separate dorsal tubercles, like those on the segments in front 

 and behind ; m, the muscles moving the seta? ; sd, the subdorsal tuber- 

 cles ; m, the retractor muscles of the tubercle ; a, one of the setaj, 

 much enlarged, with the bases of two others ; a', a", a'", ends of other 

 setae, containing at the end globules of the medullary fluid. The setae 

 are seen to be smooth, without spinules of any sort. It is to be ob- 

 served that in the double dorsal tubercle there are only four setae on 

 one side and five on the other, but five must be the normal number, 

 and the number usual in the larva? of the group at this stage. 



Stage II. — June 23. Length 14 to 15 mm. They have most 

 probably moulted, the lateral pair of upright parallel slashes having 



* In A. luna the suranal plate is triangular, but slightly shorter than in 

 T. polyphemus, the two tubercles are wider apart, not so near the end of the 

 plate, and are much lower and natter, while those of T. polyphemus are quite 

 high and slender, papilliform. 



