100 MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 



the middle. Compared with A. mrglniensis of this stage the tubercles of the plate, as well as the 

 rest of the body, are smaller, while those on the suranal plate are larger than in ^1. senator/a. 



While at first there are no oharacteristic markings, at the end of this stage appear faint 

 traces of the eight dark lines, which are more pronounced in the next stage. 



One larva molted July ii4, and two or three molted for the first time July 3(i. When al)out 

 to molt it was 12 mm. in length. 



Stage II. — Length, 7 mm.; at the end of the stage. 10 nun. Head nearly twice as large as 

 before and still black. The body is now dark, including the prothoracic shield, and the two horns 

 and all the tubercles are also black, as well as the suranal plate and abdominal legs, includino- 

 abdominal segments !> and Id. (Compare PL L. lig. -la; LII, fig. 3tf.) 



At first after hatching the bodj- is pale, the future dark portions not yet being pigmented, 

 but toward the end of the stage the seven Mack lines hecome distinct. The spines now become 

 large and well developed, but short. The underside of the body is livid green. 



The two horns are twice as long as in thejirst stage. (PI. LI, fig. 2.) 



Of the seven dai'k lines or stripes the medio-dorsal or vascular line is narrow, while the one 

 on each side is much wider; the next below (supraspiracular or subdorsal, containing the series 

 of spines of that region) is not so wide or quite so dark as the two wider doi-sal ones. The 

 spiracular line (including the spiracles) is narrow, and a little fainter. Thei-e are no lines below 

 this, and the underside of the body is not pigmented. 



So far as I can .see, the lines appear sinuiltaneously along the whole body; they ditJer in inten- 

 sity, becoming darker toward the middle of the stage, the pigment being deposited more abun- 

 dantly after exposure to the light. 



Stage TIL — Described Julj'27, when just about to molt. Length, liU uun. ; length of horns, 

 7 nan. ; width of head, 2 mm. The head is now Indian or cherry red. The body is rather dark, 

 livid, cherry red, but without the white granulations of stage IV. 



The spines on prothoi-acic segment black, more jagged, forked, and pointed than in stage 

 IV (where they are rounded at the tip and bear a single seta). 



The two hoi'ns with much longer, slenderer ))arbs than in stage IV. 



Suranal plate black above, beneath reddish, the ))lack, upper surface contrasting with the 

 dull, reddish hue of the body. Anal legs with a large, red, triangular spot inclosed in the dark 

 edge. The mid-a)idominal legs dull cherry red, with a black spot above the planta. There are 

 faint indications of a dark spiracular line. The spiracles are blackish, but smaller than in 

 stage IV. (For details of the armature see PL L, fig. 25, 2e/ LI, fig. 25/ LII, fig. Zl. ) 



In stage III there is a decided change in the markings; the dark lines of stage II are now 

 much modified. Thej' have become faint, and only traces of them remain, while a new kind of 

 ornamentation, the white granulations, appear, ^^'ith the disappearance of the dark stripes, the 

 traces of the two longitudinal pink lines now appear, a new plan of coloration being thus 

 installed and not apparently inherited from a previous ancestry. The three dorsal lines are 

 now blended together into a broad, pale, reddish band, and the pale or whitish line on each side 

 of the head is emphasized, this becoming the upper one of the two pink lines of the later stages. 



Stage IV. — Length, 21-25 mm.; length of the mesothoracic horns, 10 mm. The horns are 

 longer and less spinulated than in stage HI, and the body is black, dotted with porcelain-white, 

 uneven setiferous graiuilations. Head Indian red or dull cherry red. Pratlioracic segment irlth 

 six large stoat forked .ynnes., where those of A. rirginie/hs/K are small, almost rudimentary, and 

 they are larger than in the final stage. These spines vary, however, in being rounded, not 

 forked, and l)earing a single seta. Also the porcelain white graiudations are much larger than 

 in .1. virginietisis. The horns on the second thoracic segment are movable and much longer 

 than in the last stage, being nearly twice as long in proportion. The dorsal spines on all the 

 succeeding segments are of nearly the same size, fjcing nearly one-half as long as the body is 

 thick; those on the third thoracic segment are unevenly forked and of the same size as those of 

 the sixth and eighth abdominal segments; those on segments 1-5 being a little smaller; those on 

 the third thoracic segment are more regularly l>ifid than the abdominal ones, which ha\e the 

 smaller fork lower down. The single median spine on the ninth segment is no larger than either 



