THE GLACIAL RANGE CONTRACTION, ETC. 93 



the range base of a portion was undoubtedly in Iberia 

 and North-west Africa, many of them with southern 

 representatives remaining as evidence of that olden 

 habitat, and most of which continue to visit that area 

 in winter, or breed from North-west Africa or Iberia 

 north to areas as high as the British Islands or even 

 yet higher latitudes, but which, from a variety of 

 reasons dealt with below, do not breed in our area, 

 and can only be regarded as abnormal visitors to it. 



1 It is probable that these species were once indigenous to the British Area, although 

 now e.xtinct (conf. Ibis, 1S91, pp. 385, 386). 



