MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 



133 



Stage II. — (Probably stage II, as the increase in size between the latter stages is very 

 marked.) Length, 25 mm. The head (width, 2.8 mm.) is rather large, rounded, as wide as the 

 body, smooth and shining, mahogany brown, with two faint black shades converging toward the 

 apex. The bodj' is somewhat slender, the skin smooth and didl tlesh-brown, with smoky l)lackish 

 marks, the spines and spinules a little paler than the body and tipped with black. The prothqracic 

 segment is broad, the front edge raised and flaring, with a transverse row of six black spines, 

 four dorsal and one subdorsal; of the four dorsal the inner two are about as long as the bod}- is 

 thick, and sharp at the end, with long spinules; the two adjoining spines are minute. The four 

 spines on the second thoracic segment are much larger, the outer ones on the second and third 

 thoracic of nearly the .same size, but the inner two on the third thoracic segment are a little 

 longer than those on the second. 



The spines on abdominal segments 1-8 are of even size, and armed with long spinules; they 

 are about two-thirds as long as the body is thick, and end in two long diverging spinules. On 



Fig. 19. — Armature of Cithcronia regalis. Stage I. a, the first abdominal segment, showing the relative position of the spines: sp, spiracle: 

 b, one of the dorsal prothoracic "horns;" c, one of the dorsal liornsof the third thoracic segment: d, one of the dorsal abdominal spines, 

 those on segments 1-6 not differing in size or structure, near the base are two minute blunt setie; e-h, the armature of the last three 

 abdominal segments: <r, the caudal horn; c', the subdorsal spine of the same (eighth) segment; /, one of the dorsal spines of the ninth 

 segment, which is evenly forked at the end; ri, one of the large lateral spines arising from the suranal plate (x); h, the end of the 

 suranal plate. .\11 the figures drawn with the camera to the same scale. 



the eighth segment, arising from a large, fleshj' base, is a much spiimlated caudal spine, nearly 

 half as long as the large thoracic ones; it is mostly black, but flesh-colored in the middle. 

 Behind it, on the ninth segment, is a median dor.sal horn, about one-third as large as that on the 

 eighth. 



The suranal jjlate is small, rough, hearing two large spines; the end is rounded, with two 

 minute spines between the last pair of lateral spines: the anterior two of the spines on this plate 

 are larger, but simpler than those on the ninth abdominal .segment, and end in four spreading 

 spinules, the main stem being nearly smooth. 



The prothoi'acic segment is blackish, reddisii dark flesh color in the middle; the second 

 thoracic segment is of nearly the same color, Init the third is entirely black. The stigmata are 

 black, surrounded by a blackish cloud, while in front is a velvety black oblique dash, and beneath 

 a flesh-colored oblicjue raised ridge or fold. All the legs, both thoracic and abdominal, are black; 

 the anal pair are large, rough, and black. There is a large spine undei- each spiracle. 



