2 ALLEN'S NATURALIST'S LIBRARY. 



on its posterior margin, whereas in the Skuas there is only 

 one ; the toes are more or less fully webbed, but the claws are 

 small and feeble, whereas in the Skuas the latter are terribly 

 curved and sharp. 



The family Laridce is divided by Mr. Howard Saunders into 

 three sub-families, viz., the Terns (Sternina), the Skimmers or 

 Scissor-bills (Rhytichopince), and the Gulls (Larincz). The 

 Scissor-bills are entirely tropical, and are found in South 

 America, Africa, and India. They are river Terns, with 

 a most peculiar bill, which is not only compressed like a knife- 

 blade, but the lower mandible is produced far beyond the 

 upper one. These Scissor bills only frequent rivers, where 

 they nest on the sand-banks. 



In the compilation of the following notes on the Laridce 

 I have borrowed largely from the recent writings of Mr. 

 Saunders. He has so completely made the subject his own, 

 having studied the group minutely for the past thirty years, 

 that there seems to be little left for anyone to discover, as 

 far as the description of the plumages go. I have therefore 

 adopted his conclusions, and have quoted many of his notes 

 on the plumage and habits. 



THE GULLS AND TERNS. FAMILY LARID^. 



I have already alluded to the characters which distinguish 

 the Laridce from the Skuas, viz., the absence of a cere, the 

 double-notched sternum, the fully webbed toes, and the feeble 

 claws. The range of the family extends over the whole of the 

 world. 



THE TERNS. SUB-FAMILY STERNIN^. 



Although it is very difficult to say where the Terns end and 

 the Gulls begin for a large Tern is very like a small Gull 

 Mr. Saunders has given a clear definition of the characters 

 which distinguish the three sub-families of the Laridce. To 

 the Scissor-bills (Rhynchopince) I have already referred, and 

 their peculiar bill separates them at once. The Terns differ 

 from the Gulls in the form of the bill, which is slender and 

 nearly straight, the two mandibles being almost equal in length. 

 The tail is slightly or distinctly forked. 



