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Mareca Penelope, European ; occasional in America. 

 Machetes pugnax. do. do. 



Merganser castor. Common to both continents. 

 Merganser serrator. do. 



Merganser cucullatus. American ; accidental in Europe. 

 Phalacrocorax carlo. Common to both continents. 

 Sterna hirundo. do. 



Sterna arctica. do. 



Sterna Dougalli. do. 



Hydrochelidon nigrum. The European and American species 

 are supposed to be distinct. 



Hydrochelidon full gino sum. American ; accidental in Europe. 

 Megalopterus stolidus. do. do. 



Gavia eburnea. Common to both continents. 



