the. Structure of Hierococcyx ^c. 607 
tinued in a straight line to the neighbourhood of the cloacal 
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 Phoenicophainse. The intrinsic 
syringeal muscles are attached to the sixth semi-riug in 
It. 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 brouchi. 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 differences 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 Hierococcyx) , with wider interspaces of 
membrane, instead of abutting closely upon each other. 
