
NOTES ON THE OSTEOLOGY OF SCANSORES. 
tails with great effect in supporting themselves during their search 
for insects on trees. 
The Toucan has the power of turning his tail over his back ; 
and, as might be expected, we find a nearly true ball and socket 
joint, which, in conjunction with the tapering superior vertebral 
process, enables him to perform this feat. 
The Woodpeckers haye great motive power in the tail; but the 
apparatus, although resembling that of the Toucan, is not nearly so 
perfect, 
The terminal joint of the caudal vertebra in the Toucan is broad 
and much flattened on its lower surface; that joint, in the Parrot, 
is laterally compressed. The same bone in the Woodpeckers and 
Cuckoos appears to hold an intermediate station, the bone, at the 
Same time that it is elongated, being compressed and much flattened 
inferiorly, 
The numbering of the yertebre of those species of Scansores, 
that I have examined, is as follows :— 

Cer. Dor. Sac. Caud. 
Rhamphastos erythrorhynchus ........-s1eee 12 8 All 7 
Plyctolophus galeritus .........0-0:++ Le El 9 11 6 
Calyptorhynchus cookii. .....ce.se 13 o° deamnpte 
Platycerens zonarims............ ll 9 ul 6 
Paleornis columboides ¢....... ll 9 12 6 
Phznicophans tricolor ........ ll oad 6 
Coceyzus chrysogaster ........ 1 8 11 6 
Psilophogon pyrolophus ..... ll 9 10 7 
Turacug buffonii..sccccccssecsesesevsenuscsssvsessessseeseees 12 8 11 7 
On comparing the above list with the numbering of the vertebrae of 
other families of birds, it is found on the average, that there are 
fewer cervical vertebra than among Razores, Cursores, Gralla- 
tores, or Natatores, and that the number is about the same in the 
Fissirostral type, and fewer than in Raptores. The scelerotic 
plates are thirteen in Rhamphastos, Pstttacus, and Turacus, and 
twelve in Pheenicophaus. 
It now remains for me to point out what station I conceive the 
Stroup of scansorial birds, as at present limited, to hold amongst 
birds im general, and also the relative position of the families com- 
Posing it. I am aware that many Naturalists are of opinion, that 
the tuitions ought to form a group distinct from Scansores, but 

