376 Lord Walden on a new Species of Tricliostoma. 
particulars will be found in the article on this species (there 
styled Archibuteo lagopus , var. sancti-johannis ) in the third 
volume of the f History of North-American Birds/ by Messrs. 
Baird_, Brewer, and Bidgway. 
The iris in this species appears to be liable to variations of 
colour similar to those which occur in the case of A. lagopus . 
There remains but one other species of the genus Archi¬ 
buteo, the beautiful A.ferrugineus of Western North America— 
a species which, as it seems to me, is most obviously and un¬ 
questionably distinct, but which, nevertheless, has been unac¬ 
countably held by so high an authority as Professor Schlegel 
to be merely “ quelque sort de leucoi’sme, ou, si Pon veut, 
d’erythrisme ” of A. lagopus *. 
This fine and well-marked species has been fully described 
by Mr. Sharpe, and also in the exhaustive work of Messrs. 
Baird, Brewer, and Bidgway. The latter authors give a 
table of measurements taken from six males and six females 
of this species, none of which, however, appear to equal the 
principal dimensions of the adult described by Mr. Sharpe. 
The colour of the iris in this Buzzard seems to be as vari¬ 
able as in A. lagopus and A. sancti-johannis : Mr. Sharpe 
describes it as “ brown” in the adult; whilst the authors of 
the American work above referred to mention an adult male 
in which it was a “ clear light yellow,” and an adult female 
in which it was a “ light ochraceous brown.” 
[To he continued.] 
XXXV.— Description of a new Species of the Genus Tri- 
chostoma from the Island of Celebes. By Arthur, Vis¬ 
count Walden. 
(Plate XI.) 
In JardiDe’s f Contributions to Ornithology 5 (1849, pp. 127, 
128, t.) the late Mr. Strickland gave a short account, 
accompanied by a figure, of a Celebean bird on which he 
bestowed the title of TrichfLstoma celebense. On the prece- 
* Vide Mus. des Pays-Bas, Bevue de la collection des Oiseaux de Proie, 
p. 105. 
