214 
MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 
before. The sides of the seeond and third thoracic segments are yellowisli with reddish lines, 
and on the sides of the seventh abdominal segment is a pair of lobed bright straw-yellow spots 
converging behind, and lower down are tliree yellow tubercles tipped Avith broAvn. There is a 
similar single yellow tubercle on each side of the ninth segment. The prothoracic dorsal tubercles 
are soinowliat smaller than those on tlie first abdominal segment, and tlie eighth pair are also a 
little smaller, but all the other dorsal tubercles are still large and conspicuous. 
The mme stage. — Length, 0 mm. Head re<ldish amber, not dark coral-red as in the mature 
larA^a; angular on the sides, with two thick, stout, rather large, black tubercles on the vertex, 
bearing a hair; there are also fiv^e or six piliferous warts on each side of the head. Body with 
large piliferous warts, those on the protboracic and first abdominal segments much larger (about 
three times) than the others, those on the iirothoracic a little slenderer than those on the first 
abdominal segment; those o.n the eighth segment broader at the base, and rather larger than 
those on the first abdominal segment; those on the mesothoracic slightly larger than those on 
the meta thoracic; those oji the second abdominal very slightly larger than those on abdominal 
segments 3 to fi, 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 those 
on the head, bear slender hairs which are about one-third as long as the body is thick, and which 
are broad and flattened at the end, which is abruptly truncate. All the tubercles on the body 
are of the same color as the body, Avhich is of a general mottled reddish hue, with no- distinct 
traces of longitudinal bands, except along the base of the legs; the skin is minutely dotted Avith 
white specks and Avitli small lateral black i)iIiferous warts. 
The only bright spots are the light straw-yelloAv bases of the dorsal tubercles on the second 
and third thoracic segments, besides a pair of latero-dorsal oblique bright yelloAv patches on the 
seventh abdominal segment and a small bright yelloAV spot on each side of the base of the tenth 
segment. All the legs, both thoracic and abdominal, are coucolorous with the body. The anal 
legs are normal, but smaller than the others, with numerous hooks, and are held slightly uplifted. 
Third stage. — Length, 9 mm. The body is rather stouter than in the previous stage. The 
head is black, and all the tubercles on the liead 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 eu<l in a hair, 
noAV acute and simple, Avhile the tubercles themselves are higher and more pronounced than 
before. There are traces of a vsubdorsal and two lateral lines (these are eftaced by the alcohol). 
Fourth stage. — 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 rclatu’e size and shape; those of the third thoracic segments are of the 
same size and height, 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 tAA'ice as large as those on the scA^enth segment. The body is still reddish, 
with (in the alcoholic specimen) traces of three or foitr reddish lines on each side, which are 
bordered more or less regularly Avith Avhitish. 
Fifth and last stage. — Length, 23-30 mm. Some notable changes hav’e occurred in the 
coloration, AAdiile the shining black spines are much larger and more imposing than in the earlier 
stages, all these changes adapting the caterpillar more completely to its exposed 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 jArothoracic dorsal spines, 
instead of being larger than the other thoracic spines, as in Stage II, are much smaller, being 
only 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 slender, and 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 thud thoracic segment (smaller in 
specimens 30 mm, in length), those of the following segments decreasing in size to those of the 
seA^euth segment, Avhile those on the eighth are slightly larger than those on the tenth segment. 
The suranal plate is rounded, lozenge-shaped, with a roAv of four large piliferous warts extending 
across the middle, Avhile around the hinder edge are four smaller ones. On each side of the black 
