214 MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 



before. The sides of the second and third thoracic segments are yellowish witli reddish lines, 

 and on the sides of the seventh abdominal segment is a pair of lobed bright straw yellow sjKrts 

 converging behind, and lower down are three yellow tubercles tiiiped witli brown. There is a 

 siinilarsiiigle yellow tubercle on each side of the ninth segment. Tlu' prothoracic dorsal tubercles 

 are somewhat smaller than those on the first abdominal segment, and the eighth pair are also a 

 little smaller, but all the other dorsal tnbercles are still large and consi)icuons. 



The same xUuje. — Length, <! nun. Head reddish amber, not dark coral-red as in the mature 

 larva; angular on the sides, with two thick, stout, rather large, black tubercles on the vertex, 

 bearing a hair; there are also tive or six piliferous warts on each side of the head. Body with 

 large piliferous warts, those on the prothoracic and first abdominal segments much larger (about 

 three times) than the others, those on the prothoracic a little slenderer than those on the first 

 abdominal segment; those on the eighth segment broader at the base, ami rather larger than 

 those on tlie first abdominal segment; those on the mesothoracic slightly larger than those on 

 the metathoracic; those on the second abdominal very slightly larger than those on abdominal 

 segments 3 to (i, the latter slightly decreasing in size from before backward, and all considerably 

 smaller than those on the ninth and tenth abdominal segments. All the tubercles, except tho.se 

 on the head, bear slender hairs which are about (Uie third as long as the body is thick, and which 

 are broad and tiattened at the end, which is abru|)tly truncate. All the tubercles on the body 

 are of the same color as the body, which is of a general mottled reddisli hue, with no distinct 

 traces of longitudinal bands, excei>t along the base of the legs; the skin is minutely dotted with 

 white specks and with small lateral black piliferous warts. 



The only bright spots are the light straw-yellow bases of the dorsal tubercles on the second 

 and third thoracic segments, besides a pair of latero dorsal oblique bright yellow patches on the 

 seventh abdominal segment and a small bright yellow spot on each side of the base of the tenth 

 segment. All the legs, both thoracic and abdominal, are concolorous with the body. The amil 

 legs are normal, but smaller than the others, with nnmerons hooks, and are held slightly uplifted. 



Third .sta(ie. — Length, 9 mm. The body is rather stouter than in the previous stage. The 

 head is black, and all the tubercles on the head and body, together with the thoracic legs, and the 

 scale on the outside of the end of the abdominal legs are black. All the tubercles end in a hair, 

 now acute and simple, while the tubercles themselves are higher and more ])rouounced than 

 before. There are traces of a subdorsal and two lateral lines (these are ettaced by the alcohol). 



Fourth utage. — Length, 13 mm. The head is still black, with the two large black tubercles 

 present, though smaller in proportion than before. All the tubercles on the body are much as in 

 the last stage in their relative size and shape; those of the third thoracic segments are of the 

 same size and lieiglit, the pair on the first abdominal segment being longer and larger than the 

 others, and those on the eighth abdominal segment have not increased proportionately in size, 

 but are still nearly twice as large as those on the seventh segment. The body is still red<lish, 

 with (in the alcoholic specimen) traces of three or four reddish lines on each side, which are 

 bordered more or less regularly with whitish. 



Fifth and hist stage. — Length, 23-30 mm. Some notable chaiiges have occurred in the 

 coloration, Avhile the shining black spines arc nuich larger and more imposing than in the earlier 

 stages, all these changes adapting the caterpillar more completely to its exj^osed mode of life. 



The head is now deep coral-red, smooth, with no traces of the tubercles characteristic of the 

 previous stages, the vertex being smooth and simply bilobed. The two prothoracic dorsal spines, 

 instead of being larger than the other thoracic spines, as in Stage 11, are much smaller, being 

 oidy about one-fourth as long or as high as the mesothoracic pair; the latter are sometimes a 

 little thicker but shorter than those on the third thoracic segment. Those on the first abdominal 

 segment are very long, rather slen(bT, ami arise from a deep coral-red, soft, swollen hump, whose 

 soft, red, swollen sides descend so as to embrace the spiracle. The dorsal spines of the second 

 abdominal segment are of the same size as those on the third thoracic segment (smaller in 

 si»ecimens 30 mm. in length), those of the following segments deci-easing in size to those of the 

 seventh s<'gnient, while those on the eighth are slightly larger than those on the tenth segment. 



Thesnranal plate is rounded, lozenge-shaped, with a row of four large piliferous warts extending 

 across the middle, while around the hinder edge are fi)ur smaller ones. On each side of the black 



