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alittle irregular; a terminal black line and fringes as on upper surface ; 
minute and faint discal dots. 
Expanse, 32 m.m. Habitat, Colorado Territory (coll. Theo. L. 
Mead, No. 17). 
The occurrence of this genus in America is not noticed before. 
The hitherto described species are from the Ural Mountains, and 
have been taken in the evening on flowers according to Lederer. 
At first sight our species might be taken for Anartas allied to A. 
luteola, Grote, and the European A. cordigera, but the naked eyes, 
Hadena-like ornamentation, and the claw on the fore tibiae quickly 
distinguishes them. ‘This claw in On. Dayi, is shorter, stouter and 
blunter compared with a second species, which I describe here, and 
which equals On. Dayi in expanse, but in which the colors of the 
primaries above are less distinctly contrasted, while in general 
appearance the two species resemble each other strongly from the 
similarity in color of the hind wings. From the yellow-winged 
European species of Agrotis, sometimes referred under a distinct 
name to Triphaena, and which the present species casually resemble 
in the appearance of the hind wings, Oncocnemis differs struc- 
turally, among other characters, by the non-spinose middle and 
hind tibiae. 
It is with great pleasure that I name this species after David F. 
Day, Esq., of this Society, a scientist whose reading is exhaustive, 
and a friend whose kindness is enduring. 
Oncocnemis Hayesi, Grote, Plate 3, fig. 13. 
é6,—KEyes naked, strongly lashed; tibiae all unarmed but with a strong 
and rather long claw at the extremity of the anterior pair (vide Lederer, 
Plate 4, fig. 2); all the tarsi spinose. In all its structural characters this 
species agrees with On, Dayi, except that the claw is longer and the eyes 
and head a little smaller and less prominent. The primaries are dull pulver- 
ulent yellowish ashen with distinct lines, but not contrasted in their shad- 
ing. The t. p. line is distinctly continuous, shortly dentate. The ordinary 
spots are large and rather vague; the orbicular larger than in On. Dayi. 
The subterminal line is whitish, powdery, contrasting; fringes impromi- 
nently chequered. Hind wings, light, bright yellow, dusky at the base and 
along the veins; the dusky scales form an incomplete line crossing the cell 
over the cross-vein and running to internal margin; a wide terminal black 
