Packard.] «^4: [p^,^ 3_ 



Fig. 10, tubercles of last stage ; a, tubercle with venomous spinules ; 

 b, space at the base of a tubercle densely covered with caltrop-like 

 spinules ; these caltrops are very easily loosened, and can readily work 

 under tlie skin ; c, end of a tubercle ; c', part of the base of a tubercle, 

 with the granulated cuticle near the base ; d, two caltrops enlarged ; e, 

 two venomous spines, with the unicellular gland in tlie expanded base of 

 the spine ; e', a spine of different shape on tlie same tubercle (autlior del.). 



The second and tliird thoracic dorsal tubercles are a little slenderer and 

 smaller tlian the pair on the first abdominal segment. The pair on the 

 fourth abdominal segment are ueaily three times larger than those on 

 abdominal segments 2, 3, 5 and 6 ; tliose on segments 7 and 8 are of the 

 size of those on abdominal segments 4 and 1. 



The ground color is a pale, delicate pea-green ; most of the tubercles 

 are green, but the large dorsal tubercles on first, fourth and seventh ab- 

 dominal segments are now rose reddish ; the others only tuiutly stained 

 with roseate. 



It thus appears that all the essential characters of the fully grown larva 

 are assumed in the second stage, and at a period much earlier than in the 

 larvae of some, if not all, of the other Bombycine tamilits. This accelera- 

 tion of development of the adaptational characters of the larva seems to 

 occur also in Empretia, and probably in Litliacodia, and is perhaps com- 

 mon to the group. Additional observations are, however, much needed 

 on this interesting point. 



The following description is drawn up from ten larvoe kindly sent me 

 by Mr. Fred. B. Simpson from New York. It feeds on japouica, and 

 will, he says, eat the wild rose. 



Stage III. — Length, 4 mm. Body with the segments in this genus dis- 

 tinct. It is raiher narrow and elongated, nearly three times as long as 

 ■wide. The back of the body is well rounded, forming a slight approach 

 to that of ordinary caterpillars ; the segments convex, and the sutures 

 between them deep and distinct ; the dorsal region is narrower than the 

 sides, which flare out somewhat ; in transverse section the body is some- 

 what trapezoidal. The prothoracic segment forms a true hood, which is 

 slightly bilobed on the front edge, and encloses the head when the latter 

 is retracted. The head is moderately large, pale green, and the region of 

 the mouth is darker, pale chestnut. 



The three segments behind the first thoracic each bear a pair of large 

 high pear-shaped or high conical bright pale coral-red tubercles, densely 

 spinose and pappose. At the end of the body, on the three last segments, 

 are tliree similar pairs of coral-red tubercles, those of the last pair being 

 slenderer, more pointed, and projecting out backwards ; they are also 

 green, of the same hue as the body, but in the larger specimens they 

 become red. Between these two sets of large red tubercles are five pairs 

 of small green ones, wluch are one-third as large as the largest red ones ; 

 they are not situated quite so near together, and are all of the same size ; 

 the third pair are connected by a transverse greenish ridge; from this 



