297 



In the present order the bill is generally of moderate length, the 

 feet webbed, the hind toe small (occasionally wanting), raised above 

 the plane of the anterior toes and riot united with them by web. 

 The wings are long, and there are 11 primaries, but the terminal 

 one is very short and inconspicuous ; fifth secondary wanting. 

 Tail-feathers 12. Oil-gland tufted. Spinal feather-tract well 

 defined on the neck by lateral bare tracts, and forked on the upper 

 back ; th? dorsal apterium well developed. An aftershaft present. 



The skull is schizognathous and schizorhinal ; vomer well 

 developed ; no basipterygoid processes ; nostrils pervious. Cervical 

 vertebrae 15. Furcula U-shaped. Two carotids ; caeca present, 

 but small and functionless in Gulls. The ambiens is found 

 in all except Rhynchops the f em oro- caudal, semitendinosus, and 

 accessory semitendinosus are always present; the accessory 

 femoro-caudal is present in Sterna and Ithynchojps, wanting in 

 Larus and Stercorarim. 



Eggs double-spotted. Nest none or a scantv structure of grass. 

 The young are covered with down when hatched, and able to run, 

 but they are fed by the parents for some days. 



Scarcely any two writers agree as to the classification of the 

 members composing the present order. Apart from the question 

 as to whether the Auks and their allies (Alcidcp} should be placed 

 here or should form a separate group, a question that does not 

 affect the present work, for no species of the Auk family is Indian, 

 it is doubtful whether the Skimmers (llhynchopt) and the Skuas 

 (Stercprarius) should be regarded as subfamilies of Laridce or 

 distinct families, and the separation of the Terns as a subfamily 

 from the Gulls has more weight of authority than evidence of 

 structural distinction in its favour*. 



The two families of Gaviae are thus distinguished : 



Bill without a cere ; claws moderately curved, not 



sharp ; caeca rudimentary Laridae, p. 297. 



Bill with a cere ; claws strong, much curved and [p. 328. 



sharp ; cseca long Stercorariidae, 



Family LARID.E. 



No cere to the bill. Caeca smail and functionless. Sternum 

 with two notches on each side of the posterior margin. 



* In adopting the arrangement of Mr. Howard Saunders, whose valuable 

 work of many years on this order has recently been crowned by his British 

 Museum Catalogue, I accept his decision without feeling quite satisfied that a 

 different classification may not ultimately have to be adopted, as indeed he 

 himself suggests. There is much to be said in favour of making the Skuas a 

 subfamily of Laridce, uniting Larince and Sternince ae a single subfamily, and 

 raising the Skimmers to the rank of a separate family, Rhynchopidce ; or else, as 

 recently proposed by Mr. Beddard (P. Z. S. 1896, p. 303), classing all four 

 groups, Gulls, Terns, Skimmers and Skuas, as subfamilies of Laridce. 



