of the United States < 19 
Z . V ''.s« • • ’■ y * * ' r 1 - • •" " 
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ORDER ANSERES. 
Family Longipennes. 
* Nostrils immarginate. 
Genus 61. Rhincops Lower mandible much longer than the 
upper, truncated. 
62. Sterna Bill subulate, straightish, compressed, 
acute. 
63. Larus. Upper mandible hooked, without a cere : 
lower gibbous below the point. 
64. Lestris. Upper mandible hooked, covered at 
base by a cere : lower gibbous below the point 
** Nostrils tubular. 
65. Procellaria Hind toe only a sharp nail. 
66. Diomedea Feet three-toed ; no hind nail. 
Family Lamellosodentati. 
67. Anas. Bill depressed, obtuse; teeth lamelliform. 
68. Mergus. Bill slender, hooked ; teeth subulate. 
Family Steganopodes. 
* Bill entire. 
69. Pelecanus. Bill much depressed. 
70. Phalacrocorax. Bill compressed, hooked, not 
seamed above : tibise wholly feathered. 
71. Tachypetes. Bill compressed, hooked, seamed 
above: tibise wholly feathered. 
** Bill serrated. 
72. Sul a. Bill stout, straight, compressed ; face 
naked. 
73. Phaeton. Bill cultrate : face feathered. 
74. Plotus. Bill subulate : face naked. 
