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DIVISION II. 



Rostrum rectum, apice adunco. 



Beak straight, its tip bout down 



XEMA. 



XEME. 



Generic Character. 



Rostrum breve, subgracile, I Beak short, slender, straight, 

 rectum, lateratim compres- laterally compressed, its 



sum, apiee adunco : man- 

 dibular inferiore subtus 

 subangulata. 



Nares gracilumi, lineares. 



Pedes graciles ; iib'uv parte 

 inferiore nucLv. 



Cauda forficata. 



tip bent clown ; the lower 



mandible somewhat angu- 



lated beneath. 

 Nostrils very slender, linear. 

 Legs slender ; tibia- naked 



on the lower part. 

 Tail forked. 



XEMA. Leach. 

 LARUS. Sabine, Tenim 



I HE forked tail at once distinguishes this genus 

 from the rest of the Gulls, from which it also differs 

 in its more slender and Tern-like appearance ; its 

 beak and legs are much weaker than those of the 

 Gulls, and the former is much more feathered at 

 its base than that of the Gulls ; and the tibiae have 

 their lower parts, just above the knee, naked. 



