AQUILINiE. 
Circaetus Vieill * 
Bill moderate, culmen at the base straight, and much curved to the tip, which is hooked and acute, 
the lateral margins festooned ; the nostrils large, oblique, and suboval. Wings lengthened and acute, 
with the third and fourth quills equal and longest. Tail long and even. Tarsi much longer than the 
middle toe, feathered below the knee, and entirely reticulated. Toes short, strong, and covered with 
small scales, except at the tips ; the outer united to the middle by a membrane ; the claws long, curved, 
and acute. 
The species that compose this genus are inhabitants of most parts of the four quarters of the globe. They frequent 
the woody districts, the open plains, or banks of rivers, and marshy places, over which they are usually seen flying 
near the ground. Sometimes they perform lofty flights, or may be observed perched on the branch of a high tree, 
watching patiently for their prey, upon which they pounce when sufficiently near. They feed chiefly on reptiles, and 
occasionally on small quadrupeds. The nest is placed in a hole of the rock, or on the ground, and often upon lofty trees. 
It is composed of leaves, moss, and heath ; the female deposits three eggs. 
1. C . gatticus (Gmel.) Boie, PI. enl. 413. — Faleo brachydac- 
tylus Temm. ; F. leucopsis Bechst. ; F. longipes Nils. ; Aquila leu- 
camphomma Borkh. ; Aq. pygargus Briss. 
2. ? C. hypoleucos (Pall.) Keys, et Bl., Pall. Zoogr. 1. 354 — Ac- 
cipiter ferox Gmel. 
3. C. thoracicus Cuv. — Circaetus pectoralis A. Smith ; Aquila 
undulata Lieht. ? 
4. C. cinereus Vieill. Gal. des Ois. t. 12. 
5. C. coronatus (Vieill.) Cuv. PI. col. 234. — The Type of Har- 
pyhaliaetus Lafr. (1842). 
6. C. solitarius Tschudi, Faun. Peruv. p. 4. 
7. C. bacha (Baud.) Le Vaill. Ois. d’Afr. t. 15. — Faleo bibo 
Horsf. ; Faleo albidus Cuv. Temm. PI. col. If). ; Buteo melanotis 
Jerd. 
8. C. undulatus (Vigors), Proc. Z. S. 1831. 170., Gould, Cent, 
of Birds, pi. 1. — Circaetus nipalensis Hodgs. ; the Type of Hserna- 
tornis Vigors (1831). 
9. C. holospilus (Vigors), Proc. Z. S. 1831. 96. 
Pandion >Sau.f 
Bill short, culmen curved from the base to the tip, which is hooked and acute ; the sides compressed, 
and the lateral margins slightly festooned ; the nostrils moderate, sublinear, and rather oblique. Wings 
reaching to the tip of the tail, with the second and third quills equal and longest. Tail moderate and 
rather even. Tarsi short, very strong, and entirely covered with reticulated scales. Toes long, much 
padded beneath, and united at the base to the middle toe, mostly covered above with small scales ; the 
claws very long, much curved, and rounded beneath. 
These birds are equally scattered over every part of the world, but it is only in the vicinity of lakes, rivers, or pools, 
which abound with fish, that they take up their abode. The manner of capturing their prey is by closing their wings, 
and darting on it when the fish is swimming near the surface of the water. Their slender form is admirably adapted to 
this mode of catching, and their strong feet enable them to seize with a firm grasp their scaly and slippery prey, which 
sometimes exceeds their own weight, by which means the birds occasionally get drowned. Their flight is heavy, but 
easy, performed either in a straight line or in circles high in the air, suddenly turning, apparently without the least 
exertion, and rarely moving the wings. “ The nest is generally placed on the top,” says Wilson, “ of a decayed tree. 
It is composed entirely of large sticks, from half an inch to an inch and a half in diameter and two or three feet in 
* It was in the Analyse (1816, p. 23.) that Vieillot established this genus. It embraces Hcematornis of Vigors (1831). This word 
was changed by me, as it had been previously used by Mr. Swainson, to Spilornis. I now consider them synonymous with the one adopted. 
It also includes HarpylialiaiHus of Baron de Lafresnaye (1842). 
I In 1809, Savigny established this genus in the Description de l' Egypte, Zool. p. 93. 
