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CHARACTERS OF VERTEBRATE ANIMALS 



Pallas's Sand-Grouse (Syrrhaptes paradoxus) inhabits, during 

 summer, the steppes between the Caspian and Lake Baikal, 

 migrating farther east in winter, and from time to time invades 

 Europe in smaller or larger flocks, penetrating as far west as 

 the British Isles. 



Order 6. — Gulls (Gaviae) 



In many respects these birds resemble the piovers, and like 

 them are cosmopolitan, and have precocious young. They differ, 



however, in being 

 adapted to a marine 

 life, as seen especially 

 in the fact that the 

 three front toes are 

 connected by a web. 

 It may also be noted 

 that the plumage is 

 entirely or largely 

 light in colour. 



Well-known Bri- 

 tish types are the 

 Common Tern {Ster- 

 na fluviatilis), the 



Fig. IIS.— Herring-Gull [Larus argeniatiis) CommOn Gull {LarUS 



canus), the Herring- 

 Gull [Larus argentatus) (fig. 115), and the Kittiwake {Rissa 

 tridactyla). 



The other British gulls, &c., are: — Lesser Black-backed Gull (Larus fuscus); 

 Great Black-backed Gull (Z. marinus); Glaucous Gull (Z. glaucus); Iceland Gull 

 (Z. leucopterus) ; Little Gull (Z. minutus); Black-headed Gull (Z. ridibundus); 

 Sandwich Tern {Sterna Cantiacd); Roseate Tern {S. Dougalli); Arctic Tern 

 {S. macnira) ; Little Tern (S. minuta) ; Black Tern {Hydrochelidon nigra) ; Common 

 Skua (Stercorarius catarrhactes) (fig. 117); Richardson's Skua {S. crepidafus); Long- 

 tailed Skua {S. parasiticus) ; Pomatorhine Skua {S. pomatorhinus). 



Order 7. — Plovers (Limicolee) 



Here are included birds with long pointed wings and long 

 legs. The toes are not as a rule webbed, and the first toe is 

 very small. Young precocious. The distribution is world-wide. 



