324 ON THE TRACHEA AND SYRINX IN CERTAIN BIRDS. [Juiie 1, 



part of the trachea, while the presence of a membranous wall com- 

 pleting internally the upper bronchial half-rings recalls the Ardeine 

 syrinx. Mycteriu americana has a syrinx which is again intermediate 

 between that of Xenorhynchus and the typical Storks ; the bronchial 



Fig. 3. 



Fjrinx of XenorJiynrhts scncgalensis. 



rings are complete internally as in the latter, hut the rings, instead 

 of being of uniform width, are considerably narrower on the inner 

 side of the bronchus, which therefore becomes largely membranous. 

 Abdimia sphenorhyncha (fig. 2) is another Stork which presents even 

 a closer resemblance to the Herons in the form of its syrinx ; the mem- 

 branous inner wall of the bronchi is more largely developed than in 

 Xenorhynchus, indeed quite as much as in the Ardeidse ; but there 



