i64 THE NESTS AND EGGS OF BRITISH BIRDS. 



to be deserted. The holes vary in length from two to 

 four feet, and are three or four inches in diameter. The 

 end of the tunnel is widened out into a little chamber 

 about six or eight inches high, and in this the nest is 

 formed. It is a slight, loosely-fabricated structure of dry 

 grass and straws, lined with a few feathers. A colony 

 of Sand Martins is always a pretty sight, the birds 

 gliding to and fro before their ncst-holes, and entering 

 and leaving them with little shyness. 



Range of egg colouration and measurement: 

 The eggs of the Sand Martin are four or five, rarely six 

 in number. They are pure white and spotless, but not 

 quite so polished as those of the preceding species. 

 Average measurement, 72 inch in length by '48 inch in 

 breadth. Incubation, performed by both sexes, lasts 

 thirteen or fourteen days. 



Diagnostic characters : The eggs of the Sand 

 Martin are smaller and not so polished as those of the 

 House Martin, the only species with which they arc 

 likely to be confused. Tiie situation of the nest, how- 

 ever, prevents the slightest possibility of confusion. 



Family PICID.E. Genus lYNX. 



WRYNECK. 



Iynx torquilla, LinnccHS. 



Single Brooded. Laying season, May and early June. 



British breeding area: The Wryneck is another 

 local species, principally confined to the southern and 

 eastern counties of England. It becomes rare in Wales 



