Mr. R. B. Sharpe’s Catalogue of Accipitres. 313 
Cymindis, on account of its having been otherwise appro- 
priated some years previously to Cuvier having so used 
it. It seems to me, however, that Leptodon and Regerhinus 
ought to be regarded as distinct genera, for the reasons which 
have been well set out by Mr. Ridgway in the remarks 
on this subject contained in his ‘ Studies of the American 
Falconide,’ pp. 152, 156, and especially on account of the 
tooth in the tomia of the upper mandible, by which Leptodon 
cayennensis, the only species of the genus Leptodon, is dis- 
tinguished. The genus Regerhinus has (to use Mr. Ridgway’s 
words) “tomia without indentations or perceptible sinua- 
tions,” though it is right to mention that Léotaud, in his 
‘Oiseaux de Vile de la Trinidad, describes, at p. 40, the 
type specimen of his ‘‘ Cymindis pucherani,’ which in other 
respects seems to have agreed with the not very uncommon 
melanistic phase of Regerhinus uncinatus, as having an upper 
mandible, of which he says, “ son bord sans étre tout-a-fait 
droit ....n’est cependant qu’a peine festonné; a sa nais- 
sance on pourroit croire quw’il existe une petite dent ; sa pointe 
trés-effilée représente absolument celle du bec du Cymindis 
uncinatus.” 
The toothless upper mandible of Regerhinus is, I think, 
an indication that it approximates more nearly than Lep- 
todon to the genus Pernis, which I last considered, and I 
therefore propose to refer to it next. 
The most widely spread and best-known species of the 
genus Regerhinus is R. uncinatus. Mr. Sharpe does not 
mention the colour of the iris and the non-feathered parts in 
this species; and as it is a bird varying greatly in the colo- 
ration of the plumage in its immature stages, it is desirable 
to ascertain how far it is also subject to variation in the 
colour of these parts. As bearing on this subject I may quote 
the following information given by Professor Schlegel in 
the article on this species in his work on the Muséum des 
Pays-Bas, Pernes, p. 8 :—“ Iris couleur de perle, serres jaune 
d’orange, cire en dessus d’un vert foncé sale, vers le bas jaune 
d’orange, une raie verte depuis les narines jusqu’aux freins 
qui sont d’un vert bleudtre, une tache jaune d’orange der 
