XOUTII AMEItlC.W- niPiDS. 



Family ST'^TGIDiE. — The Owls. 



CiiAii. I'AC's iliri'i-tu<l loruMiil, iiml .-urr()iiiiilc(l by ii railiiUing system of rciillRMs. 

 wliii-li is lidiiiiilcd, I'xccpl, iiiikM-iorly, liy a nill' ol' slill' c()iii[iiiclly wcKbcd, (liHuicntly 

 I'oriiicd, ami M.nu'whal iccurvKl llsillici's ; Kiral rcathcrs anli'orse. lon^', and delist'. 

 I'liiiiiage vuiy soil and lax, of a llin: ddwiiy trxUiiv, lliu Irallici-s dcsiitiUu of an 

 alb'r-slial'l. Oil-j^land wilhcml the usual circlcl ol' leatlicrs. Outer webs of llio qnills 

 with the poinls ol' llie librus recnrvcd. Fcalliei's (Hi tlio sides of the forehead IVe(|nently 

 eliiiiLjated into ear-like tnfis; tarsns nsnally, and toes freiinently, densely li'atliefed. Eaf- 

 openinu- very larire, sonieliines eovered b^- a lappet. (ICsnphaL'ns destitnte of a dilated 

 eiiip ; eu'ca larjre. Maxillo-]ialatines thick ami s[ionLiy. and eiieinaehinjr upon the 

 intervening;- valley ; basipleryiinid processes always ]iresent. Outer toe reversible ; i)os- 

 lerior toe only alioiit half as Inni,' as the outer. I'oslerioi' inari^iii of the sternnni donljly 

 imk'iiled ; clavicle weak and nearly cylindrical, about eipial in length to the slerninn. 

 Anterior i)rocess of the coracoid projecteil I'orward so as to im'ct the clavicle, beneath the 

 Iiasal process of the scaimla. Eggs variable in shape, usually nearly spherical, always 

 iininaciilate, pure while. 



Tlio Owls coiLstitutc a very natural and sliiirply limited family, and tlioiigh 

 tlie species v.iry almost infinitely in tlie details of their striietiire, they all 

 seem to fall witliin the limits i)f a single stiljfaniily. 



They have never yet been satisfactorily classilied, tmd all the arrange- 

 ments which lia\e lieen either projiosed or iidopted are refuted by the facts 

 developed upon a close study into the true relatioiishi]) of the many genera. 

 The divisions of " Night Owls," "Day Owls," "Ilorned Owls," etc., are 

 purely artificial. This family is much more liomogeneous than that of the 

 Fitlconiihr, since none of the many genera whicli 1 have e.Kainined .seem 

 to depart in their structure from the model of a single su1)family, though a 

 few of them arc .somewhat alieriiint as regards peculiarities in the detail of 

 e.xternal form, or, less often, to a slight extent, in their osteological char- 

 acters, though 1 have exanuned critically only the American and European 

 species; iind there may be .some Asiatic, African, or Australian genera 

 wiiich depart so far from the normal standard of structure as to necessitate a 

 modification of this view. In the stntclure of the sternum there is scarcely 

 the least noticeable deviation in any geuus ' from the tyjiical form. The 

 ainirecialtle dilferences n])])eiir to l:e only of generic value, such as a difi'erent 

 jiroiiortionate lengtii of the coracoid bones and the sternum, and widtii of 

 the sternum in ])ro))ortioii to its Icngtii, or the heigiit of its keel. The crania 

 ])resent a greater range of variation, and, if closely studied, may afford a 

 cl(!w to a more natural arrangement than the one which is here ]neseiitcd. 

 The chief dill'erences in th(> skulls of different genera consist in the degree 

 of jjiieumaticity of the bones, in the form of the auricular bones, the com- 

 panitixe length and breatlth of the |:)iilatines, iiiul very great contrasts in tlie 



' I liavc, however, exiniiiacd the .stei-na only ot Kijdca, Ualw, Olus, Unichijolitn, Sijniium, 

 Sljcliilc, and <!iiiHi:l Kiiin. 



