no. i. BOMBYCINE MOTHS OF NORTH AMERICA— PACKARD. 215 



Figure 26. The double median dorsal tubercle of the eighth abdominal segment, showing a light median furrow, 

 the probable line of union of what in the embryo were originally separate tubercles; it bears 10 setae, arranged in two 

 lateral groups of five each. 



Stage II. (Described one or two days after molting.) Length 14 mm. The head now is quite small, scarcely 

 one-half wider than the body; it is entirely black. 



The body is dull dusky livid greenish; the tubercles are somewhat yellowish at base on the conical portion, but 

 the slender chitinous portion is shining black, and the radiating bristles are all black; one or two of them are longer than 

 the column or chitinous portion of the tubercle. The thoracic tubercles are slightly longer than those on the abdominal 

 segments, and the single median one on the eighth abdominal segment is slightly larger than those on the seventh and 

 ninth segments, and is now about twice as thick as those on the side, and bears eight bristles, the lateral ones on the 

 same segment bearing five. The prothoracic segment is a little darker than the others; it bears a chitinous black 

 plate about four times as broad as long, bearing on the front edge four setiferous tubercles of equal size, one at each 

 end, and with two yellow spots. The tubercles in general are now long and slende., with a conical base, the stalk 

 contracted and rather slender in the middle, the head enlarged and giving off the four or five bristles. There are now 

 five rows of indistinct black spots, along the body, like those so distinct in Philosamia cynthia, but they are not distinctly 

 seen; those of the median row are somewhat diamond-shaped. One was observed while molting, June 23. Length 

 15 mm., becoming 17 mm. The larva is more like P. cynthia, as directly after molting it is yellowish, and the five 

 rows of black spots are now very conspicuous, the median dorsal ones being more or less diamond -shaped; but the 

 tubercles and spines are all black. The head is black, but pale on the labrum. 



In this stage, just before molting, it spins a floor of silk longer than its body, on which to stand, its crotchets being 

 fastened in it during the process of exuviation. 



On June 28, at 9 a. m., one had just molted, having been seen to draw itself out of the crumpled end of its skin. 

 All the tubercles of the two dorsal rows are amber-yellow, except those on the second and third thoracic segments, 

 which are a little larger than the others, and deep orange. The four pro- 

 thoracic and also the two lateral rows are pale greenish, without any flesh 

 tints. At this time both the head and the prothoracic segment are entirely 

 pale greenish yellow, and the body is deep yellow, like that of P. cynthia, 

 with the black spots very conspicuous; all the spines, however, on all the 

 tubercles are black. The tubercles ' are now much stouter than before, but 

 are not yet spotted on the sides with black, as they are later in this stage. Its 

 length soon becomes from 10 to 20 mm. 



Half an hour later (9.30 a. m.)it had not changed, but by 11 o'clock 

 a.m. the four prothoracic tubercles (rather, however, three, as the inner one 

 on the right side is wanting, another malformation) and the second or 

 lower lateral row had turned dark, while the upper lateral row had begun 

 to turn dark at the base. The black patches on the sides of the dorsal 

 tubercles had also begun to appear; also the region at the base of the 

 antennae, as well as the clypeus and labrum, had turned pale. FlG 2 6. 



At 12.45 p. m. the black tints became more pronounced. The pro- 

 thoracic spines had all turned, as well as the two lateral ones, except those on the sixth abdominal segment, which 

 were still pale at the end. In the first or upper lateral row the tubercles were pale at the end. Of the two dorsal 

 rows, those of the abdomen are lemon-yellow, and dusky at base, the two on the ninth segment being pale sea-green 

 with a black patch or band on the side extending around behind. The double large median tubercle on the eighth 

 abdominal segment is now lemon-yellow, like those in front, with a large trapezoidal black patch on the posterior half, 

 which does not reach up as far as the origin of the black spines. The spiracles are ringed with black. 



By 3 p. m. all the dark portions and markings had become jet-black; there are now 10 black spots on each segment, 

 and the larva had now attained a length of 18 mm. 



Stage III; Length 20 mm. The following is the description of this stage when fully completed, and the color of 

 the markings fully established. The head is black, with the clypeal and labral regions green, while an irregular green 

 band passes back from the labrum above the eyes to the side of the head, the latter being now about two-thirds as wide 

 as the body. The larva is cylindrical, the tubercles are high and thick, the longer bristles being as long as the tuber- 

 cles themselves. All the prothoracic tubercles are black; the two dorsal ones on each side being united by a black 

 shining bridge at their base. The tubercles of the second and third thoracic segments are now deep coral-red, with 

 black bristles; they are larger than the abdominal ones, and are very showy. The two dorsal rows of abominal tuber- 

 cles are lemon-yellow with black spines, and black at the base behind and on the sides. The single median spine on 

 the eighth segment is nearly twice as thick as the others of the same segment on each side. The two lateral rows of 

 tubercles are black, with the ends of a beautiful pale blue, approaching lapis-lazuli . There are a median and two lateral rows 

 of black spots, situated between the spines; the median dorsal series consists of two spots, one in front of the other; 

 while the spiracular series consists of two, one in front and the other behind, but lower down than the spiracle. In 

 some examples the body is yellowish. 



i One tubercle on the left side of the third abdominal segment has no spines, a malformation never before observed. 



