PAI.MIPKDKS. 259 



Bill compressed. 



196. PHALACROCOIIAX. (!ormoraiit. Tail rounded. P. 

 carbo. The species of this genus have a triangular bone at- 

 tached to the occipuc on the dorsal edge of the foramen 

 magnum, and resting on the first cervical vertebrae. Some- 

 times perch on trees. 



197. PELICANHS. Tail forked. P. aquilus, or Frigate 

 bird. 



2. Margin of the bill serrated, the extremity nearly 

 straight. 



198. SULA. Gannet. Bill strong. Nail of the middle 

 toe serrated. No occipital osseous appendage. S. Bassa- 

 na or Solan Goose. 



199- PLOTUS. Darter. Bill slender subulated. Head 

 small. Neck and tail long. 



B. Base of the bill, and around the eyes, feathered. 



200. PHAETON. Tropic bird. Bill serrated. The two 

 middle tail feathers produced. P. atlwius. An inhabi- 

 tant of the Torrid Zone. 



Hind toe separate. 



Margins of the mandibles covered with teeth. Sides of 

 the tongue with pectinated tufts of bristles. 



A. Bill broad, with transverse lamellate teeth. This in- 

 cludes the genus Anas of Lin. The species of this exten- 

 sive group have hitherto been described in reference to 

 the colour of the plumage, although the forms of the bill 

 and legs yield more permanent marks of distinction. 



a. Trachea of the male, with a capsular enlargement at 

 the bronchial extremity. The limbs are short, and placed 

 far behind. 



1. Hind toe bordered with a membrane. 



u % 



