xiv NORTH AMERICAN BIRDS. 



tlie true relations of the members embraced under those heads. Enough 

 has also been adduced to eualile us to group many forms into families and 

 somewhat more comprehensive groups, definable by osteological and other 

 characters. Such are the Charadrimoi'phre, Cecomorphae, Alectoromorphse, 

 Pteroclomorjihie, Peristeromorphte, Coracomorphie, Cypselomorpha?, Celeo- 

 morplia', Aetomorjihie, and several others. But it is very doubtful whether 

 the true clew to the afSnities of the groups thus determined has been found 

 in the relations of tlie vomer and contiguous bones. The families, too, have 

 been probably, in a number of cases, especially for the passerine birds, too 

 much circumscribed. The progress of systematic ornithology, however, has 

 been so rapid within the last few years, that we may be allowed to hope that 

 in a second edition of this work the means may be furnished for a strictly 

 scientific classification and sequence of the families. (T. N. G.) 



A primary di\ision of recent birds may be made by separation of tlie 

 («) Batitcc, or struthious birds and their allies, — in which the sternum lias 

 no keel, is developed from lateral paired centres of ossification, and in wliich 

 there are numerous other structiiral peculiarities of high taxonomic import, — 

 from the (h) Carinaicr, including all remaining birds of the present geologic 

 ejwcli. Other primary divisions, such as that into A/trices and I'nnvccs 

 of Bonaparte, or the corresponding yet somewhat modified and injproved 

 Pitilopaales and Ptilopa»hs of Sund(>\-all, are oj)en to the serious objections 

 tliat tliey ignore tlie profound distinctions between struthious and other 

 birds, require too numerous exceptions, cannot be primarily determined by 

 examination of adult specimens, and are based upon pliysiological considera- 

 tions not necessarily co-ordinate with actual physical structure. 



In the following scheme, without attempting to indicate positive taxo- 

 nomic rank, and witliout committing myself finally, I present a number 

 of liigher gi'oups into which Carinate birds may be di\'ided, capalile of ap- 

 proximately exact definition, and apparently of approximately equivalent 

 taxonomic value. Poiuts of the arrangement are freely drawn from the 

 writings of various authors, as will he perceived by those competent to judge 

 without special references. I am particularly indebted, however, to the 

 late admirable and highly important work of Professor Sundevall,' from 

 wliich very many cliaracters are directly borrowed. The arrangement, in 

 effect, is a modification of that adopted by me in the " Key to Xortli Ameri- 

 can Birds," upon considerations similar to those herewith implied. Tlie 

 main jMjints of difference are non-recognition of three leading groups of 

 aerial, terrestrial, and natatorial birds, — groups without morphological basis, 

 resting simply upon teleological modification ; a general depreciation of the 

 taxonomic value of the several groups, conformabl}' with the considerations 

 presented in tlie preceding pages of this work ; abolishing of tlie group 

 Grallatores ; and recognition of a primary group Sphcnisci.^ 



' Mctliodi naturalis avhim disponendarum. tentameM. Stockliolm, 1872-73. 



° This group is insusceptible of definition. The wading birds, as usually allocated, do not 



