that connect the Orders and Families of Birds. 425 
group, may be inferred from the intervention of so great a chasm 
as that which separates the Strigide from Gypogeranus, and in- 
deed from every other known group of the order, except the Fal- 
conide, with which it has been seen to be connected on one side. 
It may also be observed that it is near the point where this chasm 
occurs that we may look for the group which immediately meets 
the Tachypetes and the Natatorial families ; the general approxi- 
mation of which to the Raptores we have already remarked, 
although the immediate point of junction between them could 
not be determined. Whether such a group may be discovered 
among those birds which have already been noticed by voyagers, 
but which are vaguely and imperfectly described ; or whether it 
may exist, hitherto entirely unknown, in the heart of those regions 
which the eye of science has not yet explored, —is a point on 
which we can of course at present only speculate, without any 
more solid foundation than conjecture. I shall therefore reserve 
all further observations on the subject, until more extensive op- 
portunities and more accurate examination, than I can at present 
have recourse to, will enable me to lay more decisive results 
before this learned body; and I shall now merely suggest the 
following attempt at arranging these families according to their 
affinities. 
Structurà magis ad rapinam Vulturide. 
idoned ; preeda superiore Falconide, Leach. 
Strigide, Leach. 
Structurá minus ad rapinam 
idoneá ; przedá inferiore. 
Gypogeranide ? 
Ord. II. INSESSORES. 
The order of Insessores, which next attracts our attention, con- 
tains, as is usually the case in typical groups, a considerably 
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