A Crag Martin’s Cavern 283 
and, zof like the House Martin, usually in the roof or on some inacces- 
sible ledge of a cavern. Several pairs often nest together. The nest 
SANDSTONE CAVERN ABOVE POOL IN BED OF TORRENT. NESTING-PLACE OF THE 
CRAG MARTIN. 
is warmly lined with feathers and the eggs, four to five in number, 
are white, spotted with grey and rusty-brown and closely resemble 
