BIRDS OF NORTH AND MIDDLE AMERICA. 7 



The Orders being* based on anatomical characters, and some of them 

 embracing forms of extremely diverse habits and correspondingly dif- 

 ferent in their external structure, it has been found impracticable to 

 introduce into the '^'Key"" external characters by means of which a 

 bird belonging to such a composite ordinal group ma}^ with certainty 

 be identified. External characters are more in evidence in the diag- 

 noses of the Suborders and g-roups of lower grade, and consequently, 

 after the ordinal relationship of a particular form has been deter- 



ischen Institutes unci des | Museum Vrolik der Universitilt zu Amsterdam | mit 



30 tafeln | ["Mach' es Wenigen recht; Vielen ] gefallen, istschlimm" | ] | 



I. Specieller Theil | Brust, Schulter mid proximale Fliigelregion der Vogel | 



I Amsterdam | Verlag von Tj. van Holkema | 1888. | (Pp. i-xlix, 1-834.) 



[II. AUegmeiner Theil | Resultate und Reflexionen aus morphologischen 



Gebiete | Systematische Ergebinsse und Folgurengen | | Amsterdam | Yer- 



lag von Tj. van Holkema | 1888 | {4">, pp. 837-1751, pis. i-xxx. ) 

 Gadow, Hans. (1) Dr. H. G. Bronn's | Klassen und Ordnungen | des | Thier- 

 Reichs; 1 wissenschaftlich dargestellt | in Wort und Bild. | — | Sechster Band. 

 Vierte Abtheilung. | Vogel. | Von | Hans Gadow, Ph. D., M. A., F. E. S. | 

 Lecturer fiir Morphologie der Wirbelthiere und Strickland-Curator der ITniversi- 

 tilt Cambridge. | — | II. Systematischer Theil. | — | Leipzig. | C. F. Winter'sclie 

 Verlagshandlung. | 1893. | (8 vo, pp. [i]-vii, 1-303, [304].) 

 (2) A I Classification | of Vertebrata | Recent and Extinct | By | Hans Gadow, 

 M. A.,Ph.D.,F. R.S. I Cambridge. | London | Adam and Charles Black | 1898. | 

 (Small 8vo; Class Aves on pp. xiv, xv, and 30-38.) (See also in Newton's Dic- 

 tionary of Birds.) 

 Newton, Alfred. A | Dictionary of Birds | By | Alfred Newton | Assisted by | 

 Hans Gadow | with contributions from Richard Lydekker, Charles S. Roy | and 

 Robert W.Shufeldt,M.D. | Partl(A-GA) | London | Adam and Chr.r'.es Black \ 

 1893. I Part II (GA-MOA), 1893; Part III (MOA-SHEATHBILL), 1894; 

 Part IV (SHEATHBILI^ZYGODACTYLI, together with Index and Introduc- 

 tion), 1896. 

 [The articles on avian anatomy in this most excellent and useful work (chiefly by 

 Dr. Gadow) have been carefully consulted, as have also that portion of Professor 

 Newton's historical sketch of systematic ornithology (in the Introduction) pertaining 

 to the later and more advanced works on the snl)ject.] 



Stejneger, Leonhard. The Standard | Natural History. | Edited by | John Sterling 

 Kingsley. | Vol. IV. | Birds. | Illustrated | by two hundred and seventy-three 

 wood-cuts and twenty-five full-page plates. | Boston: | S. E. Cassino and Com- 

 pany. I 1885. I (4to, p. 558.) 

 [All the articles in this work, except those on the Opisthocomi, Gallinte, Ptero- 

 cletes, Columbse, Accipitres, Striges, Psittaci, and Trochilidse are by Dr. Stejneger, 

 and are replete with information, both novel and valuable, concerning the classifica- 

 tion of birds. See Newton, Dictionary of Birds, Introduction, pp. 98-100.] 



In addition to the above-mentioned works, which deal with the general subject of 

 avian morphology and classification, various papers on the osteology, myology, and 

 -pterylography of particular forms Ijy Parker, Huxley, Garrod, Forbes, Lucas, Wray, 

 Clark, and others have been consulted, some of these being .specially mentioned in 

 the following i)ages. 



