the Structure of Hierococcyx (Sfc. 607 



tinued in a straight liue to the neighbourhood of the cloaca! 

 orifice : the row is at first composed of two feathers abreast ; 

 afterwards of but one. The outer part of the ventral tract, 

 which ceases to exist a considerable way before the inner 

 division, in fact at about the middle of the area of the insertion 

 of the thigh, is only a single row wide ; and the feathers 

 composing this single row get further apart as the end of the 

 short row is neared. As to the spinal tract, there appears to 

 be no break between the more strongly feathered anterior 

 region upon the neck and the less strongly feathered dorsal 

 part of the tract. The anterior part undoubtedly bifurcates 

 between the shoulders. This does not always appear to be 

 the case with this portion of the dorsal tract among Cuckoos. 



The syrinx (fig. 18, p. 606) is particularly interesting from 

 the point of view of the Phcenicophainse. The intrinsic 

 syringeal muscles are attached to the sixth serai-ring in 

 R. erythrognathus, and apparently to the fifth in the other 

 species that I have examined, viz. R. microrhynchus. This 

 state of affairs obviously approaches that characteristic 

 of the Centropine syringes, where a large number of 

 rings ensue between the bifurcation of the windpipe and the 

 insertion of the syringeal muscles. I imagine that in all of 

 these cases there has occurred, not so much a moving down 

 of the point of insertion of the muscles in question, as a 

 splitting of the tracheal part of the windpipe, whereby rings 

 or semi-rings are apparently added to the bronchi. The 

 tracheiform character of the first set of rings or semi-rings 

 in the bronchi of the Centropine birds is plain ; and it is 

 equally plain in this genus Rhamphococcyx. 



In Coccystes (represented for me by the species C.jacob- 

 inus) the syrinx is quite Cuculine in form ; but, as might be 

 supposed from the unquestionable distinctness of the genus, 

 there are some few difterences in detail from that of Cuculus. 

 As in Cuculus, the intrinsic muscles are attached to the 

 fourth semi-ring ; but the rings are very much more slender 

 than in Cuculus (and Hierococcya:), with wider interspaces of 

 membrane, instead of abutting closely upon each other. 



