170 MR. F. E. BEDDARD ON THE CUCKOOS. [Feb. 17, 



Edwards ^ has a gall-bladder ; I have failed to find one in Eudynamis 

 orientalis. 



Seeing that the gall-hladder is occasionally absent and occasionally 

 present in the same genus (Centropus), it does not appear to me to 

 be advisable to make use of it as a systematic character. 



The variations exhibited in the tendons of the patagium are very 

 inconspicuous ; the general disposition of the tendon of the tensor 

 patagii brevis has been described by Garrod " ; the only geiius which 

 at all departs from this is Geococcyx, in which the tendon of the tensor 

 patagii brevis sends off a short branch forwards attached to the 

 extensor metaearpi radialis a little way in front of the attachment of 

 the main part of the tendon. 



The number of rectrices is not, as Nitzsch has stated, constantly 

 10 ; in Guira and Orotophaga this number is reduced to 8. This 

 is another reason in addition to those stated below for associating 

 together these two genera. 



Muscles of the Thigh. — Mr. Garrod has proposed to divide the 

 CuculidcC into two subfamilies according to whether they possess or 

 lack the accessory femoro-caudal muscle ; the muscle-formula of one 

 group, the Centropodince, is therefore A B X Y ; that of the second 

 subfamily, the Cuculince, A X Y ; adding to his list those species 

 subsequently dissected by himself and also by Mr. Forbes and by 

 myself, I find the following arrangement : — ■ 



Centropodin^, a B X Y. CuculinjE, A X Y. 



Centropus phasianus. Cuculus canorus. 



Geococcyx affinis. Coccyzus americanus. 



Geococcyx sp. Piaya cayana. 



Crotophaga ani. Cacomantis sepulchralis. 



Pyrrhocentor celebensis. Saurothera dominicensis. 



Rhinococcyx curvirostria. Saurothera vielloti. 



Guira pirigua. Biplopterus ncevius. 

 Phoenicophaes sp. 

 Eudynamis taitensis. 

 Eudynamis orientalis. 



Syrinx. — So far as I have had the opportunity of studying the 

 structure of the syrinx in the Cuckoos, this organ appears to present 

 two chief modifications : — (1) the ordinary tracheo-bronchial syrinx as 

 in Cuculus ; (2) the bronchial syrinx, which has been long known as 

 characteristic of Crotophaga, but which also distinguishes a number of 

 other genera. In the following brief description of the syrinx in the 

 several genera only the more essential points have been indicated. 



Cuculus canorus. — The syrinx is tracheo-bronchial ; the tracheal 

 and first bronchial rings are largely ossified ; the anterior tracheal 

 rings are of uniform width throughout ; the posterior rin»s, as in 

 Steatornis ^ and other birds, alternately overlap each other, and so 



^ Histoire Nat. de Madagascar, Texte i. 1' partie, p. 174. 



2 Loc. cit. p. 360. 3 Cf. Garrod, CoU. Papers, p. 184. 



