CUCULI 



-217 



being perfectly complete rings, the trachea dividing, ' as in the 

 mammalia.' From the seventh onward all the bronchial rings 

 are semi-rings, the intrinsic muscles being attached to the 

 tenth. This is one extreme of the series, the other being 

 offered by such a type as Piaya. In Piaya (see fig. 137) 

 there is a purely tracheo-bronchial syrinx. The third bron- 

 chial semi-ring is of compara- 

 tively speaking enormous size, 

 and to it are attached the in- 

 trinsic muscles of the syrinx. In 

 Satirothera we have a syrinx 

 which is quite similar save for 

 the fact that the third bron- 

 chial ring is not enlarged. 

 Diplopterus is much the same 

 as the last. Cuculus has also 

 a perfectly typical tracheo-bron- 

 chial syrinx. In Eudynamis 

 there is a cuculine syrinx, the 

 last tracheal arid the first three 

 bronchial semi-rings being ossi- 

 fied ; the intrinsic muscles are 

 attached, as in Piaya, to the Fl(t< 137 ._ SyBINX OF p iayu ca , /ana 



third bronchial semi-ring. (AFTER BEDDARK). 



Plifjcnicopliaes is much the same. 



The remaining genera of cuckoos whose syrinx is known 

 are nearer akin to Crotophaga, though in them the bronchial 

 syrinx is not quite so typical. In Centropus ateralbus, for 

 instance, the first fifteen rings of the bronchi are incomplete 

 internally and are closed by membrane, but the membranous 

 area is narrow ; this area widens out at the sixteenth ring, 

 which with the following is much stronger than the pre- 

 ceeding and succeeding rings of the bronchus ; to the sixteenth 

 ring are attached the intrinsic muscles of the syrinx. Pyr- 

 rhocentor and Geococcyx have a similar syrinx. The syrinx of 

 Guira is in many respects very remarkable. On a superficial 

 view it is not unlike that of Cuddus. The voice organ in 

 this genus is placed further forwards than in the genera just 



