THE VOYAGE OF THE ' CHALLENGER.' 



Fig. 24. 



409 



Zool. Chall. 

 Exp. vol. iv. 

 pt. xi. p. 39. 



Syrinx of Pujfinus brevicauda, from before. 

 Fig. 25. 



The same, from behind. 

 Fig. 26. 



The same, from a younger bird, in which the bronchial and tracheal 

 rings have not yet coalesced. 



