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MEMOIKS OF THE 2fATIONAL ACADEMY OF SCIENCES. 
but separate. Palpi large, long, ascending, appressed to tlie front belo\y; second joint long,, 
continuous, pilose beneath; third joint small, pointed, not very distinct from the second. 
Thorax with a conical well-marked median crest, which sends off a spur backward, and a 
slight ridge on each side. Wings: Primaries oblong, more than one-half as broad as long; costa 
convex to beyond the middle, thence ascending to the uidunied apex, which is slightly pointed ; 
outer margin a little bent, entire, nearly straight over halfway down, thence regularly rounded to 
the internal angle. Venation: No subcostal cell; the lirst three branches of the subcostal vein 
turned abruptly up to the costa, and ending farther from the apex than in Gluphisia, Nadata, or 
Datana. 
Hind wings broad, apex rounded, outer edge rounded, longer than the internal margin. 
Legs densely hairy; fore legs densely hairy to the ungues. Abdomen with a long spreading 
tuft oil the upper side of the end, reaching beyond the genitals. 
Coloration: The species usually whitish ocherous, with oblique, in part dislocated, transverse^ 
lines, two of these usually forming a distinct large V-shaped mark; a deep brown patch 
extending from the vertex of the head between the antenum back to the top of the crest; the 
outer line on the costa very distinct silvery white, more or less oblique and sometimes S-shaped; 
beyond this mark is a subapical rust-red patch. 
The genus is readily ideiitiffed by the broad front, the hairy eyes, the well-pectinated 
auteunm of both sexes, the large palpi, and the unusually short and broad fore wings, which are 
not falcate at the apex; also by the well-marked dark brown median crest on the thorax, and by 
the laterally tufted tip of the abdomen. 
jEgg, — Ileuiispherical, moderately high, with irregular meridional swollen portions and the- 
surface ornamented with polygonal areas inclosed by slightly thickened walls. 
Larva. — Body rather long, slightly flattened, ornamented with bright, usually yellow, and 
dark stripes, and usually with two twin dark dorsal tubercles ou the first aiul eighth abdomiual 
segmeuts, with numerous pale hairs, Tlie tubercles (in apicalis) obsolete, the body being smooth 
but striped, as usual. In Stage I cylindrical, with fine hairs all tapering; with indications at the- 
end of the stage of lines and abdominal tubercles. 
Cocoon. — Thill, irregular iu shape, spun between two leaves. 
Fnpa. — Body unusually thick, and full and blunt at the end, with a slender cylindrical 
cremaster, ending iu two broad stout upeurved ilatteued hooks, each bearing four to five long setm. 
Geographical (listribntion. — The species are common to the Atlantic and Pacific coasts and 
the intervening region, cov^ering the Appalachian, xVustroripariun, and Caiiipestriau subproviuces. 
Whether any extends into the Mexican (Sonoran) is doubtful. The genus is represented in 
Europe ami America by several species iu each hemisphere, and does not occur iu either Asia or 
Africa, nor in the tropics. 
. SYNOPSIS OF THE SPECIES AND VAKIETIES. 
A. Lines auastomosiug; basal line dislocated ou cubical vein, uot toothed; white costal mark obliriuo or 
more nearly straight. 
Basal line forming a sharp angle; usually mouse colored I. apicalis- 
Larger and paler than Eastern apicalis var, ornata 
Pale, almost sordid white var. astorice 
Pale i)urplish; arms of V sinuous vav. bifu'ia 
Largest and palest species; white costal mark oblique; apex of V forming a loop ; no thoracic baud. 
I. iuoniata. 
Smaller than incUisa; pale subocherous; second, third, aud fourth lines much more sinuous than iu 
apicalis ov inolusa; subapical patch pale ocherous; costal mark oblique, siuuous; brown thoracic baud 
obscure I, sirigosa 
Costal mark more oblique aud distinct than iu sirigosa; no thoracic baud var. luculeuia 
Usually large; a white, nearly straight, costal mark; subapical patch ocherous /. incUisa 
Small, dark mouse-color; subapical patch rust-red var. inversa 
Small, pale ocherous; subapical patch ocherous var.p«??a- 
White costal mark oblique; subocherous, inner arm of V firmer, less sinuous yawjocosa 
Near apicalis^ pale, lines suhparallel, uot auastomosiug I. hrucei. 
Unusually dark, costal mark obscure var. vudinoma 
Smaller, basal lino bent aud curved; subapical patch very obscure var. alcthe 
B. Lines not anastomosing; V very narrow; white costal mark S-like I. albosigma- 
Paler subapical patch brown var. specifica 
