6 



71. Sulidae, 



72. Tacliypetidae, 



73. Graciilidae, 



74. Plotidae, 



75. Phaethontidae, 



The Gannets. 

 The Frigate Birds. 

 The Cormorants. 

 The Snake Birds. 

 The Tropic Birds. 



Order XL — Longipennes. 



76. Laridae, 



(Larinae.) The Gulls. 



76 Laridae, 



(Lestridinae.) The Jaegers. 



76. Laridae, 



(Sterninae.) The Terns. 



76. Laridae, 



(Rhynchopinae.) The Eazor-bills. 



77. Procellariidae, 



(Diomedeinae.) The Albatrosses. 

 77. Procellariidae, 



(Procellariinae.) The Petrels. 

 77. Procellariidae, 



(Halodrominae.) The Sea-runners. 



Order XII. — Pygopodes. 



78. Colymbidae, 



79. Podicipidae, 



80. Alcidae, 



81. Spheniscidae, 



The Divers and Xoons. 

 The Grebes. 

 The Auks. 

 The Penguins. 



