MEMOIRS OF rilH NA'IIONAL ACWDK.MV OK SCIKNCES. 67 



Dr. II. S. .h'wctt liiis ali't'udy (Pupilio. II. pp. 1^8 iind 144) fully (k'scrihcd the egg and the 

 larval and ])upal stayos of this iiiterostiiig iiisoct, arid I ha\(^ only to add sonic details omitted ))y 

 him. .My descriptions wefe drawn up from living speeimens. supi)lemented l)y e.xamination of 

 the aleoholic speeimens of the different stages. We have, perhaps, a no more interesting and 

 beautiful eatei-pillar. whether we consider its peculiar appendages, its rich and gorgeous colora- 

 tion, or its defensive haliits, and the most carefully descrihcid details will not he superfluous in 

 comparing the dift'ereiit stages with those of its allies, C'itheronia reyaliH and Eades imperialts, 

 anil the allied South American forms. I am indebted to my friend, Mr. W. N. Tallant, of 

 Columbus, Ohio, for sending me a good supply of eggs from which the second or July ])rood 

 of larva? hatched. The food plant is the honey locust {Gleditschia triacanthoi)^ though Doctor 

 Jewett adds GijmnocJudus ca)i<((lei(s!v, or Kentucky coffee-tree. 



Egg. — Flattened oval, disk like, each end alike. Length, l.S mm.; width, 1..5 nun. At 

 first green in color, as the embryo grows, states Jewett, the egg becomes biconcave and changes 

 to yellowish brown, and from thirty-si.x to forty-eight hours before hatching the head of the 

 larva shows through as a dark brown spot. The egg is about one-half as large as that of Eacles 

 imperkilis, but of the same shape. The shell under a lens appears smooth, like parchment; 

 under a one-half inch objective the surface is seen to be ornamented with very faint polygonal 

 impressed areas, which are much fainter and less easy to detect than those of the egg of E. 

 inipei'iafis. The swollen nucleus or bubble in each polygon is very indistinct. 



It is interesting to compare the sculpturing of the shell with that of E. imperialix and Cith- 

 e^'onia regalls, the former being intermediate between Adelocephala and Citheronia. In E. 

 imperialis the shell is sculptured a little more distinctly with irregular pol3-gonaI imprints which 

 are not so closely crowded as in Citheronia, and the median raised nucleus or bubl)Ie is pale but 

 tolerably distinct. Length, 3 mm.; width, 2.5 mm. In the shell of the egg of C. rega lis the 

 polygonal impressed cells are easily recognized under the microscope and faintly detected under 

 a strong lens. The cell imprints are much more distinct and more crowded than in the two other 

 genera, while the median nucleus or bubble is more piominent and darker; it varies in diameter 

 in different cells, being from about a third to a half as wide as the cell itself. The walls are quite 

 irregular and not always distinct. 



Larva stage I. — (Described four to five hours after hatching.) Length, 4 nun. The head is 

 large, rounded, smooth, unarmed, except with a few scattered tapering dark hairs; it is blackish 

 chestnut; it is wider than the body and slightly wider than the prothoracic segment, which is 

 broad and flaring in front, as in Anisota; it is rather higher than wide, and on the vertex 

 slightly liilolied, and is paler in front than behind. The terminal joint of the antenna is slightly 

 bulbous and bears, besides the tactile bristle, about three olfactory rods. 



The body is subcylindrical, a little flattened, but not so much so as in Ani.sota. The protho- 

 racic segment is broad and flattened, smooth and unarmed, except with about a dozen dark small 

 hairs. On each side of the second and third thoracic segments is a subdorsal pair of i-emarkabie 

 movable spines, nearly two-thirds as long as the body, which open and close together like great 

 arms, spreading apart, or directed foi'ward and outward more or less constantly while walking, the 

 creature at this age being rather active; they are evidently at this period defensive or deterrent 

 organs; they are stout, thick at the base, those of each pair close together at their base; they 

 slowly taper toward the end, and are armed with 12-14 short, thick. l)lunt. dark spines. At the 

 end of the spine is a remarkable bulbous expansion somewhat chestnut shaped, being a little 

 flattened and subtriangular, broad at the end, from each side of which arises a .small slender 

 tuljercle bearing a blunt, stout, dai'k, rod-like spine about a third longer than the tubercle. The 

 appendages themselves are dark chestnut, pale amber at base and on the outer third, but the 

 bulbous tip is dark reddish black. Those of the the third thoracic segment are very slightly 

 shorter than the pair in front, and in each pair the outer, i. e.. subdorsal spine is the shorter. 

 These horn-like appendages are flexible, especially near the end, and are sometimes bent over 

 and around, so as to form a decided bow or curve, or even a nearly complete circle. Compared 



