MEMOIKS OF THE NATIONAL ACADKMY OF SCIENCES. 71 



Prothoracio .sejjineiits very slii>litly wider tliaii the rest of tlie body in front; the front ed<re 

 flaring and rising up somewhat collar-like; this edge armed with a single row of white tubercles, 

 al)out 1<) on each side of the segment, those above nearly adjoining at base and tinged with 

 yellow; those on the sides below ])ure snow-white: behind the front edge; are four small but 

 distinct white warts, two in the middle. 



The second and third thoracic segments eacii with two widely separated pairs of horns, not 

 <|uite so thick as the caudal horn, each about two-thirds as long as the segments l)earing them 

 are wide; they are slightly recurved and scattered over them are conical, white tubercles which arc 

 irregular and blunt at the end; they are yellowish at base, near the middle becoming dark pink 

 and at tip reddish black-brown. On the front edge of the second thoracic segment between the 

 horns is a row of three conical sharp tubercles, with a similar and some minute ones on each 

 side, while on the third segment are two similar white warts. 



Across the dorsal side of the abdominal segments 1-7 are two rows of white, sharp, conical 

 tubercles; two of those on the front edge of each segment being longer and sharper than the 

 othei's and directed backwards. On these same .segments (1-7) is a third set of curious tubercles, 

 mosth' large, conical and black internally, but on the outside shining opalescent pearl or silvery 

 white, and resplendent, glittering brightly by lamplight. Of these curious spines those on the 

 first abdominal segment are smallest, and those on segments 4^6 are largest, being about one- 

 third as long as the caudal horn; the pair on segment 6 being the largest. The ''caudal horn" 

 on the eighth segment is large, with a few white tubercles, those at the end of the horn being- 

 reddish; the tip is slightly forked, there being two minute tubercles; all tho.se on the sides of the 

 horn bear a short, tine hair. In the middle of the ninth abdominal segment and in a position 

 homologous with the caudal horn, is a minute, short, median, white wart, which is reddish at tlie 

 base. The suranal plate and hind legs are very large, the surface rough and heavily warted. 

 especially on the edges: the lower edge of the anal legs and suranal plate are interrupted with 

 black. The eighth and ninth segments and base of the suranal plate are a little wider than the 

 middle abdominal segments. The suranal plate is a little longer than wide, subacutely triangular, 

 the tip forked and ending in two rather large tubercles, which are greenish at the end, blackish at 

 base, with a little transverse median black stripe in front. 



The stigmata are deep ilesh-colored, with a slit in the middle, whitish, especially at the end. 

 The stigmatal line along the side of abdominal segments 1-S is whitish, edged above with purple, 

 and still above washed irregularlj' with livid, greenish blue, while from the eighth segment to 

 the tip of the sui-anal plate the line is straw-yellow. Below, near the base of the feet, is a lateral 

 row of sharp, black spines; there are several on the sides of the thoracic segments, and 

 one rather large one under each spiracle, with smaller, sharp ones below. The thoracic 

 legs are black; the middle al:)dominal legs large, greenish, with tw^o or three alternating 

 rows of sharp, black spines near the base, and also with fine, white tubercles like those on the 

 rest of the body. Along the middle of the under side of the body the skin is immaculate green. 



Stage Y and last. — Length, 35-38 mm. (Jewett saj-s from two to two and a half inches 

 when fully grown). The head is now not angular but rounded, though slightly narrowing and 

 produced above; dark pea-green, considerably darker than the body; with a broad, yellow band 

 beginning on the antenna? and fading out on the vertex. The ocelli are black; the mandibles 

 black: the anterior lobes of the labrum l)rown, including the palpi. The head is about two- 

 thirds as wide as the body, the surface covered with tine minute granulations arranged in groups 

 (only seen under a strong, Tolles len.s). 



The bod\- is thick; the prothoracic segment short, and not so wide as the second thoracic 

 segment. It is unarmed; its front edge with a transverse series of white, bead-like warts set 

 close together. Behind, the body is thick, being of the same thickness as far as the eighth 

 abdominal segment. Second and third thoracic segments each with two pairs of very large spines, 

 whicii are about two-thirds as long as the body is thick: the outer one of each pair is slightlj' 

 shorter and slenderer than the inner, but those of both pairs are alike in size; they are roseate, 

 pale coral-red and not so near in tint to the spines oi tiie food-plant as in tiie ^-oung; when the 



