BIRDS OP NORTH AND MIDDLE AMERICA, 619 



^he BubonidsB are more nearly cosmopolitan than the Tytonidae, 

 tig absent only from Polynesia, representatives of the family 

 sting in Madagascar, New Zealand, the Hawaiian islands," and 

 Arctic districts. Thirty recent genera and nearly three hundred 

 cies and subspecies are recognized, of which eighteen genera and 

 lut one hundred species (including subspecies) are American. 

 )wing to the circumstance that the most important structural 

 iracters are not evident in dried skins, a satisfactory arrangement 

 the genera is hardly possible at this time. If all the genera had 

 m as carefully examined from freshly killed specimens as have 

 se of northern Europe, by Dr. Collett, the matter would be greatly 

 iplified, since the form, size, etc., of the external ear-opening affords 

 excellent character, though a classification based on this alone 

 uld probably be far from perfect. Nitzsch, Pycraft, Hubert Lyman 

 rk, and others have studied the osteology and pterylography of a 

 ited number of forms, and so far as their investigations have 

 ended much has been learned; but unfortunately a very large 

 iportion of the genera have not been available for study from 

 shly killed or alcoholic specimens, and hence any arrangement 

 )sible at the present time must be considered provisional only. 



KEY TO THE AMERICAN GENERA OF BUBONIDiE. 



external ear-opening extremely large, its vertical axis equal to at least half the 

 greatest height of skull, crossed by a median ligament or bridge, its margin (at 

 least the anterior one) produced into a dermal flap of greater or less width. 

 , Head without distinct, if any, ear-like feather tufts; ear-orifice either in lower 

 part of the external ear-opening, below the transverse "bridge" or (left ear 

 of Cryptoglaux) on both sides of the latter, 

 c. Cranium conspicuously asymmetrical, abnormal on both sides; external ear- 

 openings broadly oval, of equal size, slightly asymmetrical, the marginal 

 flap nearly equally developed all round, relatively narrow in front; seventh 

 and eighth b primaries longest; two outer primaries with inner webs emar- 

 ginated; tail less than two-thirds as long as wing, nearly or quite truncate; 

 size small (wing 133-188 mm.). 

 d. J'oes feathered (except in C. ridgwayi); ear-tufts very 



minute or obsolete Cryptoglaux (p. 622). 



dd. Toes wholly naked; ear-tufts distinct though very small. 



Gisella (extralimital).c 



The single Hawaiian species is, however, one of nearly world-wide range {Asia 



pitrinus). 



Third and fourth from outside, not counting the rudimentary and concealed 



renth primary. 



Gisella Bonaparte, Ann. Sci. Nat. (Zool.), 4 ser., 1, 1854, 112 (nomen nudum) 



r. et Mag. de Zool., vi (2), 1854, 541. (Tjrpe, Strix lathami Boiia.Tpaxte= Nyaale 



•isi Cassin). — Nyctalatinus "Kaup, 1854" Gray, Cat. Gen. and Subgen. Birds, 



5, 135. (Type, N. albipunctatus 'Ka,UTp=Nyctale harrisi Cassin.) — Nyctalitinus 



endation) Sclater and Salvia, Nom. Av. Neotr., 1873, 116. 



olombia to southern Brazil; two species. (It is possible that "Cryptoglaux " ridg- 



i, of which only the young is known, may belong to this genus. If so, the two 



ips are hardly generically distinct.) 



