﻿332 ON THE CLASSIFICATION OF BIRDS. 



that at least they follow each other. The circular series 

 cannot be closed more perfectly ; and thus we have an 

 additional proof that the very errors of such men, if 

 rightly used, will often afford instruction. 



(267.) In now attempting to trace the natural series 

 of this group, the most difficult, and certainly one of 

 the most confused, in the whole range of ornithology, 

 we wish to be understood as confining our exposition 

 to the primary divisions and genera only, without at all 

 attempting to designate other types of form than those 

 already enumerated. We have been constrained to 

 show how little dependence the ornithologist engaged 

 in this task can place in books ; so that nothing but a 

 personal examination of a large number of the foreign 

 species will enable him to fill up those blanks he will 

 still perceive in the series. We have been obliged, also, 

 even in this preparatory arrangement, to reject the 

 genera Noctua, Bubo, and Ulula ; and we still hesitate in 

 admitting Syrnium, uncertain at present whether the 

 brown owl of Britain is really one of the types of the 

 genus Stria;. On the other hand, it has been absolutely 

 necessary to designate the groups here named Scotiapteoc, 

 Scotophilus, Heliapteoc, and Nyctipetes ; the characters 

 of which, moreover, have this advantage, that they are 

 drawn both from internal organisation and external 

 aspect. The characters of the five genera will now be 

 concentrated in the following table of the entire family. 



STRIGIDiE — The Owls. 



Genera. 



1. Typical Group. Ears large, operculated ; no egrets. Strix. 



2. Sub-typical. Ears smaller, no operculum ; egrets. Asio. 



Ears small ; no egrets or operculum ; disk 

 imperfect. 



f Head small ; claws feathered ; tail short. Nyctea. 



3. Aberrant. A Head large ; claws naked ; tail moderate. Nyctipetes. 



C Head small ; claws feathered : tail wedged. Surnia. 



(268.) We know too little, both of the scientific and of 

 the natural history of the birds composing these groups, 

 to admit of their analogies being traced among other 

 families, at least with that precision which is desirable. 

 Nevertheless there are not wanting indications sufficiently 



