162 
MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 
diverging tubes, out of wliicb tbe spray is probably forced. Their ends do not reach to the sides 
and are not visible from them, but the gland is much as that of Cerura as figured by Fonlton 
(Trans. Ent. Soc. London, 18S7, PI. X, fig, 7.) 
Stage III . — August G. Length, 11 mm. The liead is now pale amber, but still dusky on the 
vertex, and it is also still wi<ler than tlie body. On each side of the body is a hunt whitish 
subdorsal line. The “caudal horn” is dark brown, now nearly as long as the eighth segment is 
thick vertically. The horn is slightly retractile in this stage, and the base is movable, being 
capable of withdrawal and extension and is distinctly uutaut, the apex sometimes hanging over 
backward. The sides of the body along the base of both the thoracic and abdominal legs are 
now dark reddish chocolate brown, being of the same color as the horn. 
The lateral yellow line is icell marled. The body beneath is pale green. The spiracles form 
a dark tlot surrounded by pale greenish. 
Stage IV. — Length, liO mm. August 25, The body is now thicker than before. The head 
is distinctly bilobed, rounded, narrowing a little tow'ard the vertex. The caudal horn is now 
larger, higher, and more acute than in the preceding stage; it is freely elevated or allowed to fall 
over backward, is soft and flexible, but very slightly retractile, and bears a few scattered fine 
bristles. It has a blackish shade extending up from a point above the last spiracle to the ai>ex, 
which is dark. The body is chocolate colored; the head redder, finely mottled with paler 
reddish. The sui'anal plate is well rounded behind, the surface roughened, with no piliferous 
warts, and this and the anal legs ai*e more reddish than the body, being of a reddish pink hue. 
The spiracles are much larger than in Stage III, and are blackish, surrounded by a broad, pale, 
flesh-colored ring. The middle abdominal legs have a shining chitiuous black patch above the 
planta, there being no such patch on the anal legs. The thoracic legs are dark, pitchy amber. 
Mature larva. — Length, 40 mm. The head is usually of the reddish color of the body, but 
lighter and mottled. Xow all the characters of the larva are assumed. The body is of a peculiar 
pearly hue, with a porcelain-like polish, the head being of the same tint as the body. The head 
is smooth, not quite so wdde as the prothoraeic segment, which is much smaller than the 
somewhat swollen second thoracic segment. All the segments are slightly swollen in the middle. 
The eighth abdominal segment is swollen dorsally, and is surmounted by a high, rather stiff, well- 
developed horn, which is not granulated, but somewhat annulated; it is black, this tint extending 
as a black lateral line below' and behind the spiracle. The suranal plate is of lieculiar shape, 
being long crescentic, and bearing a small knob in front, the surface of the whole plate being 
coarsely granulated, rust-red, becoming greenish in front. The thoracic feet are deep amber-red 
or salmon color. Of the abdominal feet the first four pairs are large and thick, conical, blackish 
in the middle, w'hile the anal pair are very small, with a rust-red callous spot externally. On the 
underside of the abdominal segments is an irregular greenish median line. Spiracles conspicuous, 
black, ringed with yellow'ish w'hite or nearly wdiite. One observed August 30, immediately after 
molting, had a very large head, nearly twuce as wide as the slender body, and the suranal plate 
was enormous, very w'ide in proporticm to the wndth of the body. Horn freely movable, wrinkled 
around the base, very black, and the black line on each side descends nearly to the spiracle, and 
is very distinct on the purplish reddish skin. 
Recapitulation . — I. (Congenital cbaracters.) The median dorsal tubercle or incipient “horu’^ 
on the eighth abdominal segment is in Stage I plainly seen to be double, the result of the 
coalescence and specialization of what were originally two dorsal w'arts. In Stage II this 
tubercle becomes a w'ell-developed, high, conical, fleshy horn. 
2. (Acquired or adaptational characters). The prothoracic plate of Stage I disappears in 
Stage II. 
3. Appearance in Stage II of the dark reddish browui spots and band on the sides of the body. 
4. Appearance in Stage III of traces of a whitish subdorsal line, ■while the lateral yellow line 
is well marked. 
5. Horn in Stage IV becoming much as in the last stage, though more flexible. 
Cocoon . — While Mr. Goodhue states that “the transformation takes place in a slight cocoon of 
dead leaves fastened together with a few silken threads, on the surface of the ground, much in the 
manner of Rarapsa myron,^’ Mr. Tepper remarks that the caterpillar enters the ground to pupate. 
