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A PRACTICAL HANDBOOK OF BRITISH BIRDS. 



Key to genera of family Corvid^. 



Tail longer than wing, strongly graduated ; first primary very narrow , 

 small, and stiff Pica, p. 21 



Tail shorter than wing, tip slightly graduated, rovmded or almost 

 straight ; 1st primary regular, half, or more than half, as long 

 as 2nd 2 



Bill and feet red ; plumage imiform black . . . Pyrrhocorax, p. 31 

 Bill black, feet brownish flesh-colour ; plimiage vinous with white, black, 



and grey ; blue on wings Garridus, p. 27 



Bill and feet black ; plumage entirely black, brown and white, or black 



and grey ,'.... 3 



White tips to tail-feathers ; body-plumage brown with drop-like white 

 spots Nucifraga, p. 23 



No white tips to tail-feathers, body-plumage black or black and 

 grey 4 



BUI under 40 mm., end of tail almost square . . Colceus, p. 18 

 Bill over 40 mm., end of tail rounded Corvus, p. 8 



Genus CORVUS L. 



CoRVus Linnaeus, Syst. Nat., ed. x, i, p. 105 (1758 — Type: C. corax 

 by tautonymy " corvus,^'' the Raven ; also by subsequent designations). 



Contains Ravens, Crows, and Rooks. Tail shorter than wing, 

 slightly graduated or rounded at end. 1st primary at least half 

 as long as 2nd ; 3rd and 4th primaries longest ; primaries exceed 

 longest secondaries by more than length of tarsus. Four outer- 

 most primaries with inner webs sinuated. Coloration black or 

 black and grey, the black often with purple, violet, or steel-blue 

 gloss ; some tropical species black and white. 



Nearly cosmopolitan, but absent from New Zealand, some 

 Polynesian Islands, Madagascar, South America, and Lesser 

 Antilles. Four species in British Isles. 



Key to species of genus Corvus. 



r Entirely black (with more or less metallic reflections) 2 

 (.Parti-coloured (grey and black) C comix, p. 11 



2 



f Much larger, wing over 380 mm. ...... C. corax, p. 9 



\ Much smaller, wing under 380 mm 3 



I 1st primary shorter than 9th, 2nd shorter than 6th . C. corone, p. 13 

 1st primary equal to or longer than 9th, 2nd longer than 6th 

 C. jrugilegus, p. 15 



