O. gruberi. Wing, 10.10; tail, 6.50; culmen, about .80; tarsus, 2.70; middle toe, 1.45; posterior claw, 1.00, its digit .80. Immature (?). Uniform grayish-umber, tinged with dull rufous on the neck; lining of the wing and tibiæ dull grayish-cinnamon. Primaries inclining to black, and showing just discernible, obscure hoary bars on their basal half. Tail brownish-gray, with a hoary cast nearer the shaft (not paler at the tip), and crossed with nine or ten narrow bars of dusky, these becoming hardly distinguishable basally and terminally. Inner webs of the primaries plain white anterior to their emargination. Head laterally and beneath obsoletely streaked with whitish. Hab. “California.”

Onychotes gruberi, Ridgway.
GRUBER’S HAWK.

Onychotes gruberi, Ridgway, Pr. Ac. Nat. Sc. Phil. Dec. 1870, p. 149.

Onychotes gruberi.

Sp. Char. Immature? (41,703, “California”; F. Gruber). Outstretched feet reaching beyond tail. General plumage dull dark-bistre, with a grayish-umber cast in some lights, darkest on the head above and back; the posterior lower parts paler and more reddish; throat and neck much tinged with pale rusty (this obsoletely bordering the feathers, which here have fine whitish filaments attached to the shafts); primaries uniform black. Tail like the rump, but with a more hoary tinge (not paler at the tip), and crossed with seven or eight very narrow obscure bars of darker, the last of which is distant an inch or more from the end. Lining of wing dark bistre, much tinged with rusty, this prevalent toward the edge; under surface of primaries white anterior to their emargination, beyond which they are ashy, approaching black at ends; ashy portion with distant, very obsolete, dusky bars, but the cheeks and throat streaked obsoletely with this color. No distinct white anywhere about the head or neck. Wing, 10.00; tail, 5.80; tarsus, 2.70; middle toe, 1.40; inner, .90; outer, 1.10; posterior, .80; hind claw, 1.00 (chord); inner claw, .91; on front of tarsus, twelve exposed large transverse scutellæ; only 1.70 of the tarsus exposed.

The type of this species still remains unique. It was sent to the Smithsonian Institution by Mr. Gruber, who labelled it as having been obtained in California. Nothing is known of its habits.

Genus BUTEO, Cuvier.