1889. ] ON THE ANATOMY OF POLYBOROIDES, 77 
With the evidence now before us there is no longer * any reason 
to doubt that the skeleton described by Gervais really belongs to 
Trichys. We gives as the numbers of vertebrze :—D. 16, L. 5, S. 4, 
C. 21, whilst I find in our skeleton D. 16, L. 6,8. 3, C. 24. The 
caudal vertebral column bears four compressed, hatchet-shaped 
chevron-bones between the fourth and eight caudal vertebrae. The 
eighth vertebra marks the boundary between the proximal and 
distal portions of the caudal series, differing much in shape trom the 
seventh as well as the ninth, and having the transverse process 
dilated into a broad lamina extending along the whole length of the 
centrum. The seven vertebre preceding it are provided with 
strong and long lamelliform transverse processes, whilst the apo- 
physes rapidly disappear from the ninth vertebra backwards. 
P.S.—Through the kindness of Dr. Jentink I have been able to 
examine one of the specimens described by Waterhouse as Atherura 
fasciculata, and find that I was right in supposing that they are 
identical with Trichys. I have to add that Dr. Jentink adopts 
now Waterhouse’s identification, an opinion which, for reasons stated, 
I do not share. Dr. Jentink also informs me that the specimens 
in the Leyden Museum come from Malacca, not from Siam.— 
March \1th. 
6. On certain Points in the Anatomy of the Accipitres, 
with reference to the Affinities of Polyboroides. By 
Frank E. Bepparp, M.A., Prosector to the Society. 
[Received February 19, 1889.] 
I have recently had the opportunity of dissecting a specimen of 
Polyboroides which died in the Society’s Gardens ; the specimen was 
deposited by Lord Lilford, who expressed a wish that the skin should 
go to the British Museum; after the bird was skinned it was still 
possible to examine into the arrangement of certain of the muscles 
and of other organs, which examination has, in my opinion, thrown 
some light upon the affinities of the bird. For this reason I think 
it worth while to publish the notes of my dissection, although this 
paper is necessarily very far from containing a complete account of the 
anatomy of Polyboroides. 
I have not attempted to give any description of its osteology, 
which has been lately worked out in detail by Prof. Milne-Edwards?, 
but in a different species, P. radiatus. This account shows that the 
supposed resemblances of Polyboroides to Serpentarius are purely 
superficial, and that in reality it comes nearest to the Buzzards. The 
position assigned to the genus by Sharpe® (in the subfamily Accipi- 
1 Proe. Zool. Soc. 1876, p. 712. 
* Milne-Edwards and Grandidier, Hist. phys. nat. et polit. de Madagascar : 
Oiseaux, tom. i. p. 50. 
3 
B. M. Catalogue of Birds, vol. i. p. 47. 
