272 
IMEJMOIRS OF TUB XATTONAL ACADEMY OF SCIENCES. 
conical tubercles, each with a short spine, tubercles one and two on joints 6 and 7 larger than the others. Cervical 
shield colored like the head; horns red-brown, their tubercles paler; body green, a broad red-brown dorsal band, 
very narrow and nearly obsolete on joints 3 and i, widening into an elliptical patch on joints .5-11 and inclosing on 
joints 7 (posteriorly), 8, 9, and 10 (anteriorly) a x»atch of the ground color, faintly bisected by a brown dorsal line. 
On joints 12 and 13 the baud is faint, only tinging these segments. Tails red-brown, twice aunulated with green; 
length, 4.5 mm. Vive days after the molt, the following description was made: Hody highest at joint 3 posteriorly; 
a red-brown dorsal band begins widely on joint 2, covering the liurns, narrow.s to a line on joint 4, rapidly widens 
and reaches the spiracle on joint 8; then narrows to a line on joint 12 and, widening again, covers the .anal plate. 
It is edged with yellow and contains, on joints 6-9, an ocherous yellow jiatcli which i.s broken by a narrow, brown 
dorsal lino and the brown tubercles. The sides of the body are clear green, dotted with yellow. The anterior 
anuulation of the tails is yellowish, the posterior one yellow. Venter, especially posteriorly, whitish. Joint 2 
edged with yellow at the sides anteriorly. 
Fonrih niatje. — Head partly retracted beneath joint 2, shaped as before and colored much the same, but yellow 
on the sides posteriorly; mouth parts whitish; a few piliferous tubercles; width, 1.9 mni. Prothoracic horns thick, 
l)ointing forward, covered with i)iliferous tubercles. The tubercles on the body are short, but bear stilf black seta*. 
They are coucolorous with the markings except tubercles one and two on joints G, 7, 10, and 11, which are larger 
than the rest and blackish. Tails covered with spixica which arise from enlarged bases. Jlody marked as in the hast 
part of the previous stage except that the paler patch on joints 6-9 is more brownish, and the anal plate is 
tinged with yellowish. Tails 5 mm. long, the extensile threads black, but white at base .and middle. 
Two days after the molt the markings had more the appearance of the last stage, the central patch (that part 
of the band on joints 4-11) being sligbtlj’ indented along its edges in each segiiiontal incisure. 
Fifih stage. — Hoad jiartly retracted below joint 2, rounded, higher than wide; clypeus small, depres.sed; red- 
hrowu, the upper two-thirds, except the clypeus, covered with little, round, yellowish dots, hut leaving an obscure 
line of the ground color on each side of the median suture; yellow at the sides posteriorly; mouth p.arts pale, jaws 
brow’ll, antenme yellowdsh; width, 3 min. Cervical shield large, horns short, rounded, smooth, without tubercles 
but sparsely punctured. Piliferous dots absent, the setje short and line. Tails spinoso, turned up at the end. Body 
pale yellow, thickly sprinkled with little whitish and browniisli dots, not very distinct; spiracles pale brown; a 
subventral row’ of brown spots corresponding to lcgsoii the x^*^*^^^***^^ axiodal segments, and a niedio-vcntrallino 
posteriorly. Dorsal band ferruginous brown, consisting of three connected patches; the first tri.anguhir, covering 
the horns, marked like the head on Joint 2 and iiarrow’ing to a line at the elevation at joint 3 posteriorly; the second 
widens raxiidly, reaching below the spiracle on joint 8, and narrows to a line on joint 11 posteriorly, being incised 
on its edges in the segmental sutures, shaded with blackish brow'u around its borders, and coutaiuing a darker dorsal 
and oblique subdorsal lino, be.side brown dots representing the tubercles; the third, on joint 12 posteriorly and joint 
13, elliptical, covering the anal plate, but largely rexilaced by whitish. All the X'‘atche8 are bordered by a continuous 
yellow line. Tails brown, green below at base and tw’i(?c aunulated with yellowisli green; length, 6 mm. 
As the stage advances a purplish tint suffuses the dorsal patches, the second one becomes darker, obscuring its 
markings, but three x>ale orange patches appear in it on each side, behind the former oblique subdoi’sal lines, distinct 
or conliuent and becoming pinkish yellow. There is a narrow, reddish edging inside the now' obscure yellow border. 
Cocoon. — Made, as u.sual in the genus, of pieces of bark and wood spun together over the hollow in the w’ood 
from which they were bitten out by the hirva. The cocoon is not so thick as that of Centra vuilthcripta, and it can 
be indented by the linger. It fits the pupa closely. 
Pupa, — Cylindrical, sllghtl * flattened ventrnlly, the ends rounded ; no cremaster. Color shining blackish brown, 
the cases darker, almost black, wrinkled, and less shining than the abdomen. Length, 14 mm.; width, 4.5 mm. 
Food plant. — Willow’ (Salix). Larvie from Yo Semite, Cal. 
If the larva* hero described are not different from those of Cerura hienspis Ilorkh. (w’hich I can not detorinine at 
present), then the name scc7q/>e?idn?m. must be referred to the synonymy; for all. the characters of the European 
species are exhibited in a series of specimens before me w’bich w’ere collected in California, Oregon, and Colorado. 
I am satisfied that C. alhiconia Strecker is only a varietal form, the transverse band of tlie fore w’ings tending to be 
narrower. 
Food plant — Populus (TLaxter). 
Habits. — The iiiotli (var. modesta) occurred at Plattsburg, X. aud at Franconia, aiipearing 
very early in tlie season, one being* taken by Mr. Hudson at light May 15, May 9 to June 20, while 
occidentalism^ has not been taken before May 11, aud cinerea and borealis not before tbe'28th. At 
Taos, N. !Mex., the normal form was cai>tured by Lieutenant Cariienter July 11. It is to be noticed 
that the normal aqiiUonaris is paler, whiter, with less heavy black marks than modesta^ and is 
most common in the West in the arid region, as well as at Washington, on Puget Sound, while 
modesta is, so far as known, confiued to New England, and the darker forms of it to the cool and 
damp region of the White Mountains. 
Geographical distribution. — Its range is very extensive, passing from the northern limits of 
tlie Hudsouian fauna, if Franconia, N. H., be regarded as an outlier of that assemblage, aud 
extending throughout the Oampestriau subproviiice westward to the Pacific Coast, through Cali- 
fornia, Oregon, aud Washington, and southward into New Mexico. 
