448 
74. Anas. Bill broader than high, depressed ; teeth 
long, lamelliform; hind toe simple. 
75. Fuligula. Bill broader than high, depressed; teeth 
lamelliform ; hind toe lobated. 
76. Mergus. Bill slender, hooked ; teeth subulate. 
Family Steganopodes. 
* Bill seamed above. 
77. Pelecanus. Bill much depressed ; edges entire. 
78. Phalacrocorax. Bill cylindrical, hooked; edges 
entire, feet entirely palmated ; outer toe longest ; tail 
rounded. 
79. Tachypetes. Bill cylindrical, both mandibles hook- 
ed, edges entire ; feet semipalmated ; middle toe much 
the longest ; tarsi feathered ; tail forked. 
80. Sula. Bill stout, straight, compressed ; edges serrated. 
** Bill not seamed. 
81. Phaeton. Bill cultrate; edges serrated; face 
feathered. 
82. Plotus. Bill subulate ; edges serrated ; face naked. 
83. Heliornis. Bill subulate ; edges entire ; face 
feathered. Toes lobated, lobes scalloped, connecting 
membrane rudimentary. 
Family Pygopodes. 
* Four-toed. 
84. Podiceps. Toes lobated : lora naked ; no tail. 
85. Colymbus. Toes palmated : lora feathered. 
** Three-toed. 
86. Uria. Bill nearly straight, pointed : nostrils half 
closed by a feathered membrane. 
