665 



GELOCHELIDON. GULL-BILLED TERN. 



The only species of this genus with which I am 

 acquainted differs from the Terns and Marsh-Terns in having 

 the hill stouter, rather shorter, with a greater, though still 

 slight, prominence on the lower mandible, and not very 

 widely different in form from that of some species of Gavia, 

 the genus of Larinae that approaches nearest to the Sterninae, 

 The tail is only emarginate or but slightly forked, and its 

 lateral feathers are rounded like the rest. Although the feet 

 are short, they are proportionally longer than in most of the 

 other genera ; the middle toe, with its claw, longer than 

 the tarsus. The digestive organs are the same as in the 

 Terns. In other respects there are no palpable differences 

 between them ; and this so-called genus, Gelochelidon, 

 though proposed by the Prince of Musignano, is not gene- 

 rally adopted. 



