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 Strigida from Gypogeranus, and in- 

 deed from every other known group of the order, except the Fal- 

 conidcB, 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 Tachy petes 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. 



Stnictura magis ad rapinam C VulturidcB. 

 idonea; pra.da superio... \ p^l^^j^^^^^ L^^ch. 



C Strigida, Leach. 



Stnictura minus ad rapinam I 

 idonea ; praeda inferiore. J 



[_GypogeranidcB ? 



Ord. II. INSESSORES. 



The order of Insessores, which next attracts our attention, con- 

 tains, as is usually the case in typical groups, a considerably 



greater 



