1885.] MR. F. E. BKDDARD ON THE CUCKOOS. 171 



present the appearance of being wider on one side than on the other ; 

 the first four bronchial semirings increase in length and in breadth 

 progressively ; they are ossified and firmly united together ; to the 

 last of these the single syringeal muscle of either side is attached ; 

 there is a well-developed bony pessulus which does not fuse with the 

 last tracheal ring anteriorly, but is inserted between its slightly diva- 

 ricated extremities ; the remaining bronchial semirings are carti- 

 laginous. 



Piaija cayana. — The syrinx of this Cuckoo is tracheo-bronchial ; 

 the last ring of the trachea (see fig. 1) is considerably more slender 

 than the rest ; the two first bronchial semirings are of about the 

 same diameter ; the third bronchial semiring is of, compara- 



Fig. 1. 



Syrinx of Piaya cayana. 



lively speaking, enormous size, and to it are attached the intrinsic 

 muscles of the syrinx, one on either side ; the following ring is much 

 narrower, but about the same lateral diameter ; the rest rapidly 

 diminish in size. 



The syrinx of Saui-othera doininicensis resembles in almost every 

 particular that of Piaya caynna ; the only difference worth remark- 

 ing upon is that the third bronchial semiring, to which the intrinsic 

 muscles of the syrinx are attached, is not so markedly larger than 

 the other rings of the bronchi. 



Diplopterus navius, again, shows no great differences in the struc- 

 ture of its syrinx from Piaya and Saurothera ; it more particularly 

 resembles the latter in the comparatively small size of the third 

 bronchial semiring. 



