It is perhaps unnecessary to state that the Eagles form a large group of magnificent, usually large, powerful birds of practically cosmopolitan distribution. They are comprised in several genera and forty or more species, and naturally the genus giving name to the subfamily is taken as typical. In the genus Aquila the bill is strong and curved from the vicinity of the cere. The wings are long, with the fourth and fifth quill longest, while the tail is of moderate length and slightly rounded or nearly even; the tarsus is feathered to the toes, thus differing from the Sea Eagles, and the toes are strong and provided with strongly curved, very large and sharp claws.