AVES. 391 



The frigate pelican, or man-of-war bird, Tdchypetes aquilus {pi. 92, fig. 

 3), is common to both the old and new worlds. 



The gannets are also arranged here. These are not so large as the 

 pelicans, though similar in many respects, and are found in immense num- 

 bers on desert and rocky islands in various parts of the world. The booby, 

 Sula hassana {pi. 92, fig. 6), and the brown gannet {S. fusca), are good 

 examples of these birds, of which there are about a dozen species. 



Sub-fam. 4. Carhonince, oi' Cormorants. Bill straight, slender, hooked at 

 the tip ; wings moderate, pointed ; tail moderate, rounded ; tarsi short, 

 compressed ; toes long, all four united by the web of the feet. Size rather 

 large ; color mostly black. 



The cormorants have been proverbial for their voracity from time imme- 

 morial, and may be termed the vultures of the sea. They are found in 

 small parties on all sea coasts, and are very successful fishers, being capable 

 of diving and swimming under the water with great velocity. In this 

 manner they capture their prey, which consists principally of fishes, and 

 which, it is said, are caught carefully by the head, so that the scales and 

 fins may not impede their being swallowed. 



There are about thirty species of cormorants, of which the common 

 cormorant, Carho cormoranus {pi. 92, fig. 1), the crested cormorant {C. 

 dilophus), the violet cormorant {G. violaceus), are the most common 

 American species ; the first of which is also common on the sea shores of 

 Europe. 



With this sub-family we complete the Class of Birds. 



595 



