INIEMOIKS OK THE NATIONAL ACADEMY OF SCIENCES. 



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Stage II. — (Probably stage II, as the increase in size t)et\veen tlic latter stages is very 

 niarlved.) Leno-th, 'J.") nii'.i. Tlie iieail (widtli. 2.S mm.) is ratiier large, rounded, as wide as the 

 bodv, sniodth and shining, mahogany brown, with two faint black siiades converging toward the 

 apex. The body is somewhat slender, tlie skin smooth antl dull llesh-brown, with smoky blackish 

 marks, the spines and spinules a little paler than the l)o(ly and tii)ped witli black. The prothorai'ie 

 segment is broad, the iixmi edge I'aised and Haring, 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 tlie body is 

 thick, and sharp at the end. with long spinules; th(> 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 tiioracic 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 regatis. 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 horns of the third Ihuracie 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 seta;; c-li, the armature of the last three 

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

 segment, which is evenly forked at the end; ,f7, one of the large lateral spines arising from the suranal plate (x); li, the end of the 

 suranal plate. All the figures drawn with the camera to the same scale. 



the eighth segment, arising from a large, fleshy base, is a much spinulated caudal spine, nearly 

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

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

 eighth. 



The suranal plate is small, rough, bearing 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 prothoracic segment is blackish, reddish dark flesh color in the middle; the second 

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

 black, surrounded by a blackish cloud, while in front is a ^'elvety black oblique dash, and beneath 

 a flesh-colored oblique 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 under each spiracle. 



