ON THE TRACHEA IN THE " EATITE " BIRDS. 

 Fig. 1. 



233 



P.Z.S. 1881, 

 p. 779. 



Bifurcating trachea of Struthio camelus, from before. 

 b. Section of wall of trachea, from behind, to show the vocal cord formed by the 



thickening of the mucous membrane of the interior. I. II., first two bronchial 



semirings. 1, 2, &c., last trachea! rings. 

 Here, and elsewhere in these figures, o indicates the last, oo the penultimate, ooo the 



antepenultimate tracheal rings. 



Fig. 2. 



The same, from behind. About natural size. 



laterally than elsewhere. The antepenultimate ring presents the same P. Z. S. 1881, 

 features more strongly developed. In two of the four specimens exa- p ' ' 

 mined it sends down a small pessulif orm process of cartilage in the middle 

 line behind, filling the chink left between the posterior extremities of 

 the two next (incomplete) rings. The penultimate ring is narrower and 



