274 MR. W. P. PYCRAFT ON THE | Mar. 17, 
The 1st lumbo-sacral shows vestiges of ventri-lateral processes. 
Only the 2nd sacral bears ribs. 
There are 8 free caudals, but the 7th is nearly fused with the 
pygostyle. The total number of vertebre is 41. 
I must here point out that the determination of the sacral 
vertebre in the skeletons herein described is a purely arbitrary one ; 
they cannot possibly be determined with certainty without ex- 
amination of the sacral nerve-plexus, and this I] am unable, at the 
present moment, tomake. Thus, it may be that the plexus will show 
that in some cases what is here described as the last lambo-sacral 
in reality is the first sacral. If this should be the case then, of 
course, the vertebra herein described as the 2nd sacral would be 
the Ist caudal. 
v. THe Riss. 
The cervical ribs, in the Cuculi, form a series of very broad pleur- 
apophyseal lamellee enclosing the usual vertebrarterial canal. These 
plates extend backwards rather: beyond the middle of the centrum. 
Seen from the ventral surface, the rib is free for about half its 
length. Certain of the vertebre in the middle of the cervical 
chain have this lamella pierced by a large fenestra. In Guwira, 
Coua, Centropus, the 5th, 6th, and 7th are so distinguished; in 
Crotophaga the 6th, 7th, and 8th; in Scythrops the 7th and 8th; 
in Taccocoua, the 4th, 5th, and 6th. Cuculus, Chrysococcyx, and 
probably other smaller forms, differ from the forms just described 
in that the anterior cervical ribs are comparatively long and 
slender, not lamellate; whilst from the 7th vertebra backwards 
the ribs are reduced to vestiges. 
The cervico-thoracie ribs number two or three pairs. The third 
pair always bear uncinates. 
There are five pairs of thoracic ribs, though not more than four 
are attached to the sternum. The fifth pair are overlapped by 
the preacetabular ilium, and may be reduced to the merest vestiges, 
e.g. Rhamphococcyx and Coua, or they may be complete, as in Sey- 
throps and Cuculus. They vary somewhat in form. For instance, 
in Coua, Centropus, and Guira the proximal end of the rib is 
extremely broad, and the shaft after leaving the vertebra almost 
at right angles, curves abruptly downwards. In other Cuckoos 
the broadening of the shaft is not conspicuous, and the shaft 
slopes gently downwards and backwards, so that the thorax 1s 
conspicuously broader at the articulation with the sternal ribs 
than above. 
The uncinates are broad and strong, and show a tendency to 
develop a sharply defined postero-inferior angle at the junction 
with the shaft of the rib; this is especially noticeable in Coua. 
The sternal segments of the 5th pair of thoracic ribs never reach 
the sternum. They may persist as vestiges, even the thoracic 
segment of the rib reaching the verge of disappearance, as in 
Coua and Rhamphococcyx, or they may be of considerable size, 
