Genus — P A N D I 0 N . 
Pandion Savigny, Descr. Egypt. Hist. Nat., Vol. I., 
pp. 69-95, 1809 
Triorches Forster, Synopt. Cat. Brit. Birds, p. 1, 1817 
Balhusardus Fleming, Hist. Brit. Anim., p. 51, 1828 
Type P. TialiaUus. 
Type P. haliaetus. 
Type P. haliaetus. 
A Falconiform bird with the outer toe reversible, and the tarsus coarsely 
reticulated throughout. 
The first sentence separates this monotypic genus from every other 
Falconiform genus save Polioaetus, from which the latter effectively divorces it. 
The bill is comparatively long, very hooked, sharp, rapidly-descending 
tip ; the lower edge of the upper mandible has a long wavy sinuated appear- 
ance, recalling the Aquiline group. The cere is rather large, the nostrils small 
ovals, semi-operculate, placed midway between culmen ridge and lower edge 
of upper mandible. 
The head bears a slight occipital crest. 
The wing is long with the third primary longest, slightly exceeding the 
second, which just surpasses the fourth : the first is long but is scarcely longer 
than the fifth, and noticeably less than the fourth and second. 
The tail is long, but is just about half the length of the wing, and thus 
appears comparatively short. 
The legs are short and stout ; feathering of the thighs advances in front 
on to the tarsus, which is entirely covered with rough reticulate scales. The 
toes are shorter than the tarsus, powerful, and the middle toe exceeds the 
inner and outer by very little : the outer toe is reversible and all the claw^ are 
practically the same length, being long and rounded. 
I have left this genus as a monotypic family, placed at the end of the 
Falconiform birds, though this is a dubious position. 
The reversible outer toe is mainly responsible for this location and this 
seems a poor character. “No aftershaft present ” has been continually added 
as a distinctive feature, but recently this has been shown to be due to 
inaccurate investigation. 
Beddard {Structure and Classification of Birds, p. 478, 1898) wrote : 
“ Pandion is undoubtedly an aberrant genus, which is by several {e.g. Gadow) 
made the type of a separate family, and is thought by some to lead towards 
293 
