vi] DISTRIBUTION OF SELECTED GROUPS 107 



Australia and to South America. The Jacanas (Parra, 

 etc.) have a similar tropical range, excepting Australia. 

 The ' Seed-snipes ' (Thinocorys] are restricted to 

 Western South America, from Ecuador to the Falk- 

 lands. The only other family with a somewhat 

 restricted range are the Coursers, Pratincoles and 

 Crab-plovers which inhabit the shores of the whole 

 Indian ocean, whence they extend far into the Old 

 World continents. 



Gulls and Terns are cosmopolitan families. 



Auks and Guillemots are decidedly northern, the 

 southern limits of these strictly marine shore-birds 

 being Massachusetts, Brittany, the Baltic, the north 

 coast of Siberia, North Japan to Lower California. 

 The famous ' Great Auk/ the only really flightless 

 member, had been exterminated in Iceland in 1844 ; it 

 was formerly common on the coasts of Denmark and 

 Ireland, and on the opposite shores of North America. 



Sand-grouse. The genus Pterocles dates from 

 the early Tertiary of France ; ranging now from Spain 

 and Cape Colony to Madagascar. Syrrhaptes para- 

 doxus, Pallas' Sand-grouse, is at home in Central Asia, 

 whence it has made irruptions in enormous numbers 

 into Europe ; cf. p. 68. 



Pigeons are apparently an Old World group, 

 dating with certainty from the Lower Miocene ; they 

 are now quite cosmopolitan. Especially rich in the 

 production of genera have been tropical islands, above 



