NATURAL SCIENCES OF PHILADELPHIA. 43 



Falco xialon, they agree in every particular. I think it most probable that 

 future careful research will demonstrate satisfactorily the existence of a 

 species hitherto usually confounded with some of the protean plumages of 

 F. columbarius; but quite distinct from the latter, and doubtless referrible to 

 the European type above mentioned. In fact, a Falco sesalon has been quoted 

 by Townsend and Nuttall as from the northwestern portions of the United 

 States ; though not usually recognized by later ornithologists. 



(5.) Falco (Hypotriorchis) femoralis Temm. 



South Arizona, near the Sonoran border. Specimens were obtained by 

 Lieut. J. G. Parke's Expedition along the 32d parallel ; and by the Mexican 

 Boundary Survey. 



It is quite possible that the F. aurantius Gm. extends northward through 

 Sonora into the southern portion of Arizona. 



6. Falco polyagrus Cassin. 



? Falco mexicanus* "Licht. Mus. Berol.," Schlegel, Abhandl. Geb. Zool. 

 u. Vergl. 1841, p. 15. Schlegel, Falcones, Mus. d'Hist. Nat. Pays- 

 Bas, 1st, 1862, p. 18. 

 Falco (Gennaia) polyagrus, Cassin, Birds N. A. 1858, p. 12. 

 Sparingly distributed throughout the Territory. Not observed at Whipple, 

 though doubtless to be found there. Colorado Chiquito River, Kennerly. 



o' 



(7.)Accipiter Cooperi Bon. 



This generally distributed species is found throughout the Territory. 



8. Accipiter Mexicands Swains. 



Common, resident. Iris, cere, legs, and feet light yellow. Bill bluish 

 black. Claws black. 



I have seen young birds of this species, reared by hand from the nest, so 

 thoroughly domesticated as to come to their master on being whistled for, 

 and perch upon his shoulder, or follow him when shooting small birds for 

 their food. They were allowed entire liberty. Their ordinary note was a 

 shrill and harsh scream ; a low, plaintive, lisping whistle was indicative of 

 hunger. 



The shape of the tail of this speeies is decidedly less rounded than that 

 of Cooperi, and is a feature of considerable value in distinguishing the 

 female Mexicanus from the male Cooperi. 



9. Accipiter fuscus (Gm.) Bon. 



Resident. Abundant throughout the Territory. 



10. BOTEO " MONTANUS" Nuttall. 



B. montanus, Nuttall, Manual, 1840, i. p. 112; and of later American 



writers generally : equals B. borealis from Western North America. 

 B. borealis, (Gm.) Gray, Genera, i. 1849, p. 11. Bryant, Remarks on 



Variations of Plumage of Buteo borealis, etc., in Pr. Bost. Soc. Nat. 



Hist, for 1861 : considers montanus Nutt., calurus Cass., and probably 



also Cooperi Cass., as referrible to borealis. 



*I think it very likely that polyagrus is not the first distinctive name this Hawk has received. 

 The description of Falco mexicanus by Schlegel, as above cited, is substantially as follows: 

 'Wing 11.50 to 13; tail 6.50 to 7 50; legs finely scaled, feet yellow; above brown, paler on the 

 tail; head and nape edged with rusty brown; quills with rust-colored spots; stripe through the 

 eye, spot on nape, and middle of auriculars whitish; beneath white, each feather with a Darrow 

 blackish drop-shaped spot; large lateral feathers covering flanks brown, with some rust-colored 

 transverse spots. The young bird has the edges of the feathers above light, the spots below 

 larger, and the feet greenish yellow." A fuller description is in the first number of Dr. Schlegel's 

 Catalogue of the Pays-Bas Museum, above cited. These descriptions are pertinent to F. polyagrus 

 in most respects; but, in view of some discrepancies, {color of the legs, which, in polyagrus, are 

 light dull blue, etc.,) I do not wish, at present, at least, to make the change of names, though 

 such a procedure may hereafter he considered necessary. Mr. Cassin himself refers (B. N. A., 

 1868, p. 12,) to this name of Dr. Schlegel's, as very probably the first designation of the species. 



1866.] 



