600 Mr. F. E. Beddard on some Points in 
in the present communication to lay a few new facts 
before the readers of this Journal. These chiefly concern the 
genera Hiero coccyx, Rhamphococcyoc , and Coccystes, Avith 
regard to none of which have we at present any adequate 
knowledge of such anatomical features as might serve to 
indicate their relationship to allied genera. Some seventeen 
years ago I made an attempt^ to arrange the Cuckoos 
according to the modifications in the feather-tracts/ the 
structure of the syrinx^ and the Garrodian leg-muscle formula. 
A subsequent investigation of the genera Scythrops f and 
Carpococcyx % served to support the arrangement which I 
originally proposed ; and the new facts which I have now to 
record point in precisely the same direction. 
Apart from subsidiary differences_, the Cuckoos in their 
pterylosis present us with two chief modifications. In one 
series of birds the ventral feather-tracts are single on each 
side of the body. In the other series the same tracts are 
divided, and thus a more complicated pterylosis is arrived at. 
This more complicated pterylosis characterizes Centropus, 
Carpococcyx, Scythrops, Eudynamis, Phcp.nicophaes and Croto- 
phaga ; the simpler ventral pterylosis^ in which the tract is 
not divided again after its first separation into two branches on 
tlie neck_, is to be found in Cuculus, Piaya, and other forms. 
In Hierococcyx varius the pterylosis is entirely upon the 
Cuculine plan. Each ventral tract is undivided. On the 
abdomen the rows of feathers constituting each tract are less 
in number than m the pectoral region. There are three 
uistinct rows of feathers, each at some little distance 
from its neighbours. This arrangement into three rows 
is precisely what occurs in the genus Cuculus. In both the 
genera referred to these three rows approach each other 
some little wav before the tract ends at the cloaca, and two 
* * " On the Structural Characters and Classification of the Cuckoos," 
P. Z. S. 1885, p. 168. 
t "On the Anatomy of an AiistraUan Cuckoo, Scythrops novce-hol- 
lanclice;' P. Z. S. 1898, p. 44. 
. X "On the Anatomy of the Radiated Fruit-Cuckoo. Cmpococcyx 
radiatus,'' Ibis, 1901, p. '200. 
