XX 



of external circumstances, must have arisen from genetic divergences. Of these suborders 

 three, viz. iEgithognathae, Desmognathae, and Schizognathae, are represented in our region, the 

 Dromaeognathas containing only the Tinamous, which are exclusively Neotropical birds. For 

 these orders and suborders I have not used the same titles as were bestowed on them by 

 Professor Huxley; but here I have followed Mr. Sclater in modifying the classification, and 

 in using such of the names already in use among ornithologists as can fairly be woven into 

 the new system. 



The yEgithognathse and Schizognathae have the maxillo-palatine bones free and separate 

 from one another, not joining in the middle line, the first of them having the anterior end of 

 the vomer truncated or cut off nearly square, and the second having the vomer pointed in front ; 

 whereas the Desmognathae have the maxillo-palatines united in the middle line. In the article 

 above quoted Professor Huxley arranges the Schizognathae first, then the Desmognathae, and 

 concludes with the iEgithognatha? ; but he subsequently (Anat. of Verteb. Anim. pp. 233-255) 

 modified his ideas to some extent, and in his arrangement commenced with the Schizognathae, 

 then following with the iEgithognathae, and concluding with the Desmognathae. I have, how- 

 ever, deemed it expedient to follow Mr. Sclater, and have therefore commenced with the 

 iEgithognathae, then taking the Desmognathae, and concluding with the Schizognathae ; for in 

 any case it appears most advisable to an ornithologist to head the list with the Passeres. To 

 arrange the different families in linear order is a simple impossibility ; for a scheme of classifica- 

 tion must be compared to a genealogical tree, of which the trunk and the bases of its main 

 branches are buried in the waters of obscurity, and the smaller branches alone are seen above 

 the surface ; therefore one must take one of the branches from as near the base as we can now 

 trace it, and follow it up to its smaller branches and leaves, and then, relinquishing it, go to work 

 on another in the same manner. In this way each must separately be treated ; and by so doing 

 the apparent incongruity of ranging widely different species next to each other vanishes ; for the 

 one will be found to spring from a totally different branch from the other. 



In this manner I have subdivided the iEgithognathae into three orders, viz. Passeres, 

 Macrochires, and Pici; the Desmognathae into five orders — Coccyges, Accipitres, Steganopodes, 

 Herodii, and Anseres ; and the Schizognathae into eight, viz. Columbce, Gallince, Grallce, Limicolce, 

 Gavice, Tubinares, Alcce, and Pygopodes. 



As may be supposed, I have found the greatest difficulty in the classification of the Passeres ; 

 and I am fully aware that the conclusions at which I have arrived are in many respects open to 

 criticism ; but the classification of the Passeres is a task that has troubled wiser heads than 

 mine, and is likely still to remain unsettled for some time to come. I am glad to find that, 

 on the whole, the classification I have adopted agrees tolerably closely with that recommended 

 by Mr. Sclater, whose essay on the subject (I. c.) is certainly the best that has yet appeared. He, 

 however, (following Sundevall) separates the Larks entirely from the rest of the Oscines, calling 

 the former Scutiplantares, and the latter Laminiplantares, whereas I have placed the Larks merely 



