682 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



or ochraceous, usually with a blackish margin; under parts mostly 

 whitish, vermiculated, barred, or otherwise variegated with brown, 

 gray, or rufous, often with black streaks and bars. Many of the 

 species "dichromatic," that is, having two very distinct phases of 

 plumage, wholly independent of age, sex, or season — a grayish or 

 brownish, conspicuously variegated plumage (which may be regarded 

 as the normal one) and a more uniform bright rufescent one. 



Range. — Nearly cosmopolitan, but wanting in Australia, New 

 Guinea, New Zealand, Polynesia, West Indies ( ?), and colder regions. 

 (About eighty species and subspecies, of which about twenty-five are 

 American and only one European.) 



Among the many species generally referred to this genus which 

 have been examined in the present connection are variations in exter- 

 nal characters which strongly indicate the necessity of dividmg the 

 group into two or more genera; but in the absence of many species, 

 some of which are types of generic names (among them the typa of 

 Otus itself) any attempt at subdivision under the circumstances 

 would necessarily be premature and futile. Thus, among the 

 species examined, 0. scops (Linnaeus) is the only one in which the 

 eighth and nmth prunaries are longest, the tenth (apparent outer- 

 most) equal to or longer than the sixth, and only two outer primaries 

 sinuated on the inner web. Superficially, this species much resembles 

 0. jiammeolus, especially in its small size and completely naked toes, 

 but the latter has the seventh and eighth primaries longest, the tenth 

 (apparent outermost) not longer than the fifth, four outer primaries 

 smuated on inner web, and the ear-tufts very short and mconspicuous, 

 instead of the reverse. The wings are relatively much longer in 

 0. scops, extending, when closed, beyond the tip of the tail, and the 

 primaries are relatively narrower and straighter distally. Again, in 

 0. nudipes the tarsi are naked for almost as great an extent as in the 

 genus Gymnasio, to the species of which genus there Is indeed a 

 closer general resemblanca than to the other American species of 

 Otus, except in the possession of distinct ear-tufts, which are wanting 

 in Gymnasio. 



In a "Review of the American Species of the Genus Scops, Sa- 

 vigny, "'^ the writer has remarked the extreme difficulty of attaining 

 a correct understanding of the specific and subspecific limits of the 

 members of this genus. This is owing to the chcumstance that not 

 only is the individual variation in any form very considerable, but 

 the matter is further complicated by the condition of dichromatism 

 which affects the majority of the species, the two phases of one form 

 (occurring in birds from the same locality, and quite independent of 

 sex, age, or season) being far more different from each other than are 

 corresponding phases of distinct species. In the main, geographic 



a Proc. U. S. Nat. Mus., i, 1S78, 85-117. 



