598 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



KEY TO THE FAMILIES OF STRIGES. 



a. Palatines straight, nearly parallel, approximately the same width throughout, 

 almost concealing maxillo-palatines, which are broader from above downward 

 than from side to side; prefrontal process of ethmoid thick and rounded; inter- 

 orbital region thick, without fenestra; metasternum shallowly 2-notched or 

 entire; no man ubrial process; sternal crest dilated; furcula coalesced with keel 

 of sternum; third (middle) toe little if any longer than second (inner) toe, its 

 second phalanx considerably longer than basal phalanx, its claw notched or 

 serrated; tarso-metatarsus without bony ring or loop; feathers of the planta 

 tarsi reversed (pointing upward); none of the primaries emarginate on inner 

 web, the outermost developed (tenth) longer than the eighth; tail emarginate; 

 ventral pteryla with outer branch united to main stem posteriorly; oil gland 



with two or three filoplumes at tip a Tytonidae (p. 698). 



aa. Palatines curved, much expanded posteriorly; maxillo-palatines largely exposed, 

 very broad from side to side; prefrontal process of ethmoid a thin plate; inter- 

 orbital thin, often fenestrated; metasternum deeply 4-notched; manubrial 

 process present; sternal crest narrow; furcula incomplete, free from keel of 

 sternum; third (middle) toe much longer than second (inner) toe, its second 

 phalanx about equal in length to the basal phalanx, its claw not notched or 

 serrated; tarso-metatarsus with a bony ring or loop on under surface of upper 

 end; feathers of planta- tarsi (when present) not reversed (always pointing 

 downward); at least one (sometimes six) primaries with inner web emargiaated 

 or sinuated, the outermost developed (tenth) primary shorter than eighth; tail 

 usually more or less rounded, rarely truncate, never emarginate; ventral pteryla 

 with outer branch free from main stem posteriorly; oil gland without filoplumes. 



Bubonidse (p. 617). 



Family TYTONID^. 



THE BARN OWLS. 



=Strigina Vigors, Zool. Joum., ii, Oct., 1825, 393. 



=Strigmse Bonaparte, Prodr. Syst. Orn., 1840, 4. — Cassin, in Rep. Pacific 



R. R. Surv., ix, 1858, 47.— Gadow, in Bronn's Thier-Reich, Vog., ii, 1891, 



236, 301. 

 ^Striginse Bonaparte, Consp. Av., i, 1849, 54 (includes genus Phodilus). — 



Gray, Hand-list, i, 1869, 52. 

 =8trigidx Sclater and Salvin, Nom. Av. Neotr., 1873, pp. vii, 116. — Sclater, 



Ibis, 1880, 403.— Sharps, Rev. Classif. Birds, 1891, 79; Hand-list, i, 1899, 300. 

 '^Strigidse Sharpe, Cat. Birds Brit. Mus., ii, 1875, 289 (includes Phodilus). 

 =Aluconidx Coues, Key N. Am. Birds, 2d ed., 1884, 498, 500. 

 =Aluconinx Barrows, Stand. Nat. Hist., iv, 1885, 346, in text. 

 =Alucinse Newton, Diet. Birds, 1894, 674, in text. 



Striges with inner toe as long as middle toe, claw of middle toe with 

 inner edge produced and pectinated or serrate; feathers of planta 

 tarsi recurved or reversed ; outermost developed primary (tenth) longer 

 than eighth, none of the primaries with inner web emarginated or 

 sinuated; tail emarginated; face heart-shaped, with the lower apex 

 very prominent. 



o The genus Phodilus presents exceptions to some of these characters; but its true 

 position can hardly be considered as definitely settled. See footnote on p. 618. 



