xiv NORTH AMERICAX BIRDS. 



the true relations of the members embraced under those lieads. Enough 

 has also been adduced to enable us to .«,touj) many forms into families and 

 somewhat more coni2»rehensive groups, detinable l>y osteologieal and other 

 characters. Sucli are the Chamdrimoiplue, ( ecomorpha*, Alectoromorpha?, 

 I'terucLnnorphiu, Peristeromorphie, Comcomorphie, C'ypselomorpha', Celeo- 

 morjjhu', Ai'tomorphie, and several othei-s. But it is very douljtful wliether 

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

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

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

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

 been so I'apid witliin tlie last few years, that we may ha allowed to hope that 

 in a second edition of this work the means may l)e furnislied for a strictly 

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



A primary division of recent birds may be made by separation of the 

 {(() Batitcv, or struthious birds and their allies, — in which the sternum has 

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

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

 from the (/>) Carinata., including all remaining ]>irds cf the present geologic 

 epocli. Other primary divisions, such as that into Alt rices and Pracoccs 

 of Bonaparte, or the corresponding yet somewhat modified and improved 

 Pi^Uopaah'.'i and PtiJopaides of Sundevall, are ojien to the serious objections 

 that they ignore tlie profound distinctions l»etween struthious and other 

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

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

 tions not necessarily co-ordinate with actual physical structure. 



In tlie following sclieme, without attempting to indicate positive taxo- 

 nomic rank, and without committing myself finally, I present a number 

 of liigher groups into which Carinate birds may be divided, capable of ap- 

 proximately exact definition, and apparently of a])proximately equivalent 

 taxonomic value. Points of the arrangement are freelv drawn from the 

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

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

 late admirable and liighly inqiortant work of Professor Sundevall,^ from 

 which very many characters are directly borrowed. The arrangement, in 

 effect, is a modification of that adopted l)y me in the " Key to North Ameri- 

 can Birds,'' upon considerations similar to those herewith implied. The 

 njain points of difference are non-recognifion of three leading groups of 

 aerial, terrestrial, and natatorial birds, — groups without morphological l)asis, 

 resting simply uj)on teletdogical modification ; a general depreciation of the 

 taxonomic value of the several groups, conformably with the considerations 

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

 Oi'dllatvres ; and recognition of a primary group Sphemf^ci? 



' }frthodl natnralh avium dlsjinnenrjarum frntamrn. Stockholm, 1872-73. 



2 This group is insusceptible of definition. The wading bird.s, as usually allocated, do not 



