GEN. 281-291 OF KEY. 105 



550. LARUS EBURK'EUS Gm. 



Ivory Criill. 



551. LARUS BELCHERI Vigors. 



552. LARUS TRIDACTYLUS L. 



H^ittiTVulie ^lall. 



552a. LARUS TRIDACTYLUS L., 

 var. KOTZEBUi (Bp.) Coues. 

 l^acilic M.itti^vs4l4<e. 



553. LARUS BREVIR03TRIS (Brandt) Coues. 



Sltort-billedL l£itti^vs&ke. 



554. LARUS ATRICILLA L. 



I.i&iig-laiiigr €riill. 



555. LARUS FRAISTKLINI Rich. 



656. LARUS PHILADELPHIA (Ord) Coues. 



557. RHODOSTETHIA ROSEA (MacCxIll.) Bp. 



l(Vc«lg-e-taile4l CJiill. 



558. XEMA SABIN"EI (Sab.) Bp. 



f oi'K-tailed <^iill. 



559. XEMA FURCATUM (Neboux). 



Swalloiv-tailed ^ull. 



SCO. STERNA ANGLICA Montagu. 

 Criall-billed Tern ; Marsli Tern. 



561. STERITA CASPIA Pallas, 



var. iMPEUATOR Coues. 

 Caspian Tern. 



562. STERH'A REGIA Gambel. 



Iftojal Tern. — 



