GEN. 281-291 OF KEY. 105 



550. LA&US EBURNEUS GM. 



Ivory Gull. 



551. LARUS BELCHERI VIGORS. 



White-headed Gull 



552. LARUS TRIDACTYLUS L. 



Kittiwake Gull. 



552a. LARUS TRIDACTYLUS L., 

 var. KOTZEBUI (Bp.) Coues. 

 Pacific Jiittiivakc. 



553. LARUS BREVIROSTRIS (BRANDT) COUES. 



Short-hilled kittiu akc. 

 /^ 



554. LARUS ATRICILLA L. 



iLaugrhing- Gull. 



555. LARUS FRANKLINI RICH. 



Franklin's Rosy Gull. 



556. LARUS PHILADELPHIA (ORD) COUKS. 



Bonaparte's Gull. 



557. RHODOSTETHIA ROSEA (MACGILL.) BP. 



Gull. 



558. XEMA SABINEI (SAB.) BP. 



Fork-tailed Gull. 



559. XEMA FURCATUM (NEBOUX). 



Swallow-tailed Gull. 



560. STERNA ANGLICA MONTAGU. 

 Gull-hilled Tern ; Harsh Tern. 



661. STERNA CASPIA PALLAS, 



VdV. IMPERATOR CoUCS. 



Caspian Tern. 



562. STERNA REGIA GAMBEL. 

 Royal Tern. 



