330 os THE CLASSIFICATION OF BIRDS. 
the first is the typical, the second the sub-typical, and 
the third the aberrant group of the whole family. 
(264.) The genus Nyctipbtes is placed between 
Nyctia and Surnia. Of these little owls we possess four 
species from tropical America, and are acquainted witlf 
three more : they bear such an external resemblance to 
the European race, represented by S'. Tengmalmi, that all 
writers have failed in perceiving how truly they differ, 
by having very small ears, no operculum, and no in- 
dication of the marginal ruff of feathers. The want of 
egrets, on the other hand, separates them at once from 
the Scop owls. Their general structure, in short, is 
certainly very like that of the great white owl, but the 
legs are only feathered to the base of the toes ; and 
these latter, except in being thinly clothed with white 
shining hairs, might be termed naked : tbe wings are 
also short, and reach only to the base of the tail, which 
is moderately long and slighted rounded. It is clear, 
therefore, that these birds cannot possibly be arranged 
with the true nocturnal, or with the horned, owls ; and 
we are therefore led to decide that they form part of a 
genus, of which the burrowing owl of America {S. cu- 
niculata, Mollini) is probably the type. This latter 
bird differs from the structure just described in having 
the legs much longer, more naked, and the claws less 
hooked ; the tail is shorter and quite even. But in the 
more essential characters, drawn from the ears, biU, and 
head, it quite agrees with the little birds just mentioned ; 
so that one species, with legs of an intermediate length, 
wmuld be sufficient to complete the link of connection 
and such a bird will probably be soon discovered. 
( 265 .) The genus Sitrnia of Dumeril designates the 
hawk owls, represented by that of America.* These 
differ from the other two aberrant types in having a 
long wedge-shaped tail, which, with their small head 
and obsolete facial disk, gives them more the appearance 
of being hawks than any others of this family. Dr. 
* Sirix funcria. Northern Zoology, ii. p. 92., and vignette, p. 94 . 
