226 ME. W. P. PYCEAFT ON THE 



The former contained tlie genera Olaucidium, Ntjctala, Athene, Syrnia, and leroglawx, 

 the latter Scops, Otus, Bnho, and Strix. 



In the earlier editions of Yarrell's well-known ' History of British Birds,' the scheme 

 of classification which was followed for the Owls was that of dividing the group into 

 " horned " and " hornless." This jilan was discarded some six-and-twenty years ago hy 

 Prof. Newton when he undertook the task of re- writing this work (12). He adopted in 

 the main that of Messrs. Sclater and Salvin. Internal characters apart, they were 

 divided into two groups, the one, representing the Barn Owl and its allies, characterized 

 hy the disposition of the feathers of pt. ventralis, the form of the operculum, the 

 straightness of the heak at the hase, and a serrated middle claw. Tlie other was further 

 subdivided into " the Owls which possess an operculum to the ear and the Owls which do 

 not;" .... " to the first of these belong the Tawny, Tengmalm's, the Long-eared and 

 Short-eared Owls, and to the second the remainder of the species." 



Whether the subdivision adopted for this latter group is destined to prove the right 

 one or not I will not venture to say ; for my own part I have some doubt as to its power 

 to hold its own. The form of the operculum and cavernum (p. 259) in Asio and 

 Syrnium have really very little in common, whilst that of Ni/ctala can hardly be called 

 an operculum at all. 



The minor characters utilized in the formation of genera were such as the form of the 

 facial disc, length of the remiges, presence or absence of " ear "-tufts, feathering of 

 the legs, and the form of the external aperture of the ear, whetlier symmetrical or 

 not. 



Pour years after the publication of Prof. Newton's work Dr. Sharpe brought out his 

 'Catalogue of the Striges ' (16). Measurements, and such points as the size of the 

 external apertures of the ear, measured with relation to the length of the horizontal axis 

 of the eyelid, the presence or absence of an operculum, and the development of the facial 

 disc, are the characters which he adopted for the purpose of breaking up the group into 

 genera and species. 



Pollowing Sclater and Salvin, he divided the Owls into two groups — the Striyidce, 

 containing the Barn Owl and its allies, and the JBubonidce. The only external characters 

 adopted for the purposes of this di\dsion were the relative lengths of the middles 

 toe and the presence or absence of a serration along the inner margin of the claw of 

 that digit. 



The Buhmiidce were further subdivided into the Buhoiiina;, with the " ear-couch not 

 larger than the eye (? eyelid), without an operculum; facial disc unequal, the portion 

 below the eye being always much greater than the area above the latter ;" and the 

 Syrniince, with the " ear-conch much larger than the eye, with very large operculum 

 shutting in the ear ; facial disc always distinct, and extending as far above the eye as 

 below it." These two sub-families agree with Prof. Newton's — those which possess an 

 operculum to the ear, and those which do not. In addition, however, to the question of 

 the presence or absence of an operculum, Sharpe takes into account the size of the 

 aperture of the ear ; this w as a step in the right direction, but it was not enough, since 

 even now Owls are brought together which ought to be placed in separate sub-families. 



i 



