NON-INDIGENOUS BRITISH BIRDS. 105 



nine in number. They are very rotund, highly polished, 

 and pure white. Average measurement, i*o inch in 

 length by "9 inch in breadth. Incubcition is performed 

 chiefly by the female, but the duration of the period 

 appears to be unknown. 



Diagnostic characters : I know of no character 

 which will distinguish the eggs of the Bee-Eater from 

 those of certain allied species. They require careful 

 identification. 



Family CORACIID.'E. Genus Coracias. 



ROLLER. 



Coracias garrulus, LinncBus. 



(British : Rare abnormal spring and autumn migrant.) 



Single Brooded. Laying season, May and first half of June. 



Breeding area : South-western Palaearctic region 

 and North-western Oriental region. The Roller breeds 

 throughout Europe, south of about lat. 60°, with the ex- 

 ception of Denmark (where it is rare), the Netherlands, 

 Belgium, and Northern France. It becomes most 

 abundant in the countries bordering the Mediterranean, 

 Black, and Caspian Seas. Eastwards it breeds in Asia 

 Minor, Palestine, Persia, Turkestan, Afghanistan, Cash- 

 mere, North-west India (the Punjaub), and Southern 

 Siberia, as far north as Omsk and as far east as the 

 Altai Mountains. South of the Mediterranean it breeds 

 in North-west Africa, from Morocco to Tunis. 



Breeding habits : The migration of the Roller across 

 the Mediterranean northwards into Europe takes place 

 at about the same time as that of the Bee-eater, and lasts 

 through April to the beginning of May. On migration 



