Contributions to Bird-Anatomy and Classification. 3 



I. On the Conformation of the Nasal Bones^. 

 " In most birds the anterior mar§jin of the nasal bone is 

 concave^ with the two cornua directed forwards/^ these pro- 

 cesses being '^ continuous behind with the body of the bone 

 and with one another^ there being no interruption of any- 

 kind between them. Such a condition is found in Otis and 

 the Gallinae proper; and birds possessing the bone so con- 

 structed may be termed holorhinal : in them a transverse 

 straight line, drawn on the skull from the most backward 

 point of the external nasal aperture of one side to that of 

 the other, always passes in front of the posterior terminations 

 of the nasal processes of the prsemaxillse/' This simply con- 

 cave nature of the posterior margin of the osseous external 

 nares, as well as the relations of the extremities of the nasal 

 bones to those of the nasal processes of the prsemaxillse, is 

 shown in the subjoined figure of the FowFs skull (see fig. 1) . 



Fiff. 1. 



Fig. 2. 



Skull of Galliis domesticus 

 (from P. Z, S. 1873, p. 35, %. 9). 



Skull of Lams argentatus 

 (from P. Z. S. 1873, p. 34, fig. 2). 



* " On tlie Value in Classification of a Peculiarity in the Anterior 

 Margin of the Nasal Bones in certain Birds," P. Z. S. 1873, pp. 33-38. 



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