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band broader than in On. Dayi; fringes yellowish, with a dusky line, whitish 
at tips. Beneath yellowish, with terminal black bands which, on the fore 
wings, are not removed superiorly from the margin as in On. Dayi; minute 
discal dots. 
Expanse, 32 m.m. Habitat, Colorado Territory (No. 18, coll. 
Theo. L. Mead). 
This beautiful species is very distinct from Oncocnemis Dayi in 
the ornamentation of the primaries, which latter have more the 
appearance of those of the Huropean QO. diffusa (H.-S. figs. 44-45). 
Our species at once differ by their distinctly yellow hind wings. 
The geographical distribution of the genus is very interesting, 
since it increases the zodlogical homogeneity of the present Arcto- 
gaeal province. The ocelli are present in all our species, and the 
maxillae long, stout, black and corneous. 
I respectfully dedicate our second species of the genus to Doctor 
George HE. Hayes, Vice-President of this Society, whose observa- 
tions on the Geology of Buffalo, have materially increased our 
knowledge of our locality. 
Oncocnemis Chandleri, Grote, Plate 3, fig. 9. 
4 .—Kyes naked, strongly lashed; all the tibiae without, all the tarsi with 
spines; fore tibiae with a strong claw. Fore wings gray, mixed black and 
white, distinctly contrasted and with longitudinal black streaks, resembling 
in this respect On. Dayi. A distinct black dash runs from the base of the 
primaries to the long, black-margined claviform. Transverse lines indicated on 
costal region, else obsolete. The appearance of the gray ordinary spots is 
very peculiar; they are fused by a common black edge and distinct shaded 
fillings. The compound spot assumes a decumbent funnel-shape. Very evi- 
dent longitudinal black dashes precede the white dentate subterminal line 
interspaceally. Fringes alternately paler and darker. In the ornamentation 
of the primaries this species remind us of Cloantha. The terminal space is 
dark and concolorous in On. Chandleri, whereas it is paler than the sub- 
terminal in On. Dayi. Hind wings pale fuscous or smoky, with a diffusely 
margined, wide, blackish hind border, which, in one specimen, does not con- 
trast greatly with the rest of the wing. Beneath paler than above, with 
terminal blackish borders and minute discal points. 
Fzpanse, 32m. m. Habitat, Colorado Territory (coll. Theo. L. - 
Mead, No. 27). 
Quite distinct from the species with yellow hind wings, this 
resembles On. Dayi, rather than On. Hayesi, in the ornamenta- 
