MKMUIKS OF THE NATIONAL ACADEMY OF SCIENCP:S. 27 



pale reddisli but iimcli paler at base; the eaudal horn ninth palei- than the thoracic ones. There 

 is a black ring around the base of tlie thoracic legs. The spiracles arc deep purple ai'ound the 

 edge, those of the eight abdominal pair darkest, becoming palei- toward the first segment; the 

 prothoracic ones only partially stained with purple. In Bridgham's drawings the spiracles are 

 drawn with a blackish ring (PI. IX). The midabdominal legs are dusky brown at base, and 

 the plantio blackish. The- anal legs or claspers and also the suranal plate are yellowish, but 

 black in the middle area, though the granulations are yellowish. The head has a dark short 

 line on each side, and two diverging dark lines on each side of the chpeus. 



Stage V{hi.st). — A blown specimen is uniformly deep pea green, with no brown shade. The 

 head is as in Stage IV, but green l)ehind the yellowish front. The spines are j'ellow, with no 

 red discoloration on them. The spiracles are deep pui'ple, and do not become paler anteriorly. 

 They are drawn bluish purple" In- Mr. Bridgham (PI. IX). T!ie suranal plate and anal legs are 

 identical in coloration with those of Stage IV. 



T lie hrown form. — I will tirst describe a fidly grown blown example of the same size and 

 shape as the above-described green larva. The body is reddish brown; with three paler, clearer, 

 subdorsal ditiuse irregular patches on each segment, forming two obscure broad interrupted 

 longitudinal bands. The region about each spiracle is also paler brown, forming an oblique oval 

 patch, passing fi'om the front edge of the segment downwai-d. The pale yellowish spiracles are 

 very conspicuous and are surrounded by a dark purple ring. The spines are fully as stout as in 

 the green form, and the body is equally hairy, the hairs being whitish. The head diflers from 

 that of the green form in the greater amount of dark brown, both on the .sides and along the 

 middle in front, yet the back part of the sides, that corresponding to the green portions in the 

 green larva, is dull obscure yellowish. The colors of the suranal plate and of the anal legs are 

 nnu'h as in the green form, but a greater extent of the anal legs is biack-lirown. The thoracic 

 legs are yellow, but the midabdominal ones dark brown. 



Stage IV. — It diflers from the green one of this age in being bright reddish, the tut)ercles 

 of the same hue, while the head is reddish, as are the legs, thoracic and abdominal, while the 

 edges of the suranal plate and anal legs are tinged with reddish. The spiracles are surrounded 

 by a brown ring. 



A third form, a true dimorphic form, appears to be that represented on PI. VIII, tig. f,. I 

 will describe a specimen received by exchange from the museum of the Brooklyn Institute. It 

 diflers structurally in the slightly stouter tubercles and denser hairs. In color it diflers from the 

 brown form above described in being of a rich, dark um])er or Vandyke brown. The subdorsal 

 row of pale sienna brown patches is more distinct, and the series is made up of a single large 

 Sfiuarish patch, situated on tiie front edge of each segment, except the prothoracic and the nintii 

 and tenth abdominal. The spiracles are conspicuously straw-yellow with a bi'own ring (I can 

 detect no purplish hue in the dried specimen); the oval ol)lique patches inclosing them are of the 

 same hue as those on the tergum, and also those of the brown form. The head (PI. VIII. tig. (!'/) 

 is nearly all black-brown on the sides and in the middle, leaving an irregular yellow Iwnd on each 

 side of the front: the anterior clypeus and labrum are also yellowish or luteous. The suranal 

 plate is dark brown, as are the anal legs, except the front edge of the legs, which are yellowish; 

 the secondary tul)ercles or granulations are yellowish. The thoracic legs are yellow and black; 

 the midabdominal ones brown-black. The tul)ercles are all black-brown. 



T/ie three color format of Citlieronla regal l-i. — Mr. A. Hyatt Verrill has called my attention to 

 some striking color variations of this caterpillar, of which he took photographs in color somewhat 

 touched up by hand. Tiie variations are in green, green and orange, blue, and brown. ]\Iy 

 notes are taken from his colored photographs as I have not yet had the fortune to see the larva 

 of tiiis species while alive. 



In all the forms the size. .-ha]ie. and colors (orange, red, and black) of the spines are the same, 

 as also the color of the head, thoracic and abdominal legs, and the suranal plate. 



"In the plate, liowever, they are unfortunately printed lilac-k. 



