324 ON THE TRACHEA AND SYRINX IN CERTAIN BIRDS. [June I, 
part of the trachea, while the presence of a membranous wall com- 
pleting internally the upper bronchial half-rings recalls the Ardeine 
syrinx. Mycteria americana has a syrinx which is again intérmediate 
between that of Xenorhynchus and the typical Sturks; the bronchial 
Fig. 3, 
Syrinx of Xenorhynchus senegalensis. 
rings are complete internally as in the latter, but 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 Ardeide; but there 
