152 THE USEFUL BIRDS 



4 inclies in the opposing wall. Diameters : — Structure, 4.25 

 inches x 3.75 inches ; in bowl, 2.25 inches. Depth of bowl, 

 1.25 inches. 



The nest is made to fit in a cavity with domed ceiling in 

 an excavation in the hard subsoil at the end of a tunnel. 

 This tunnel is 10 inches long, and is drilled with a slig?it 

 upward tendency, as is usual with most ground-boring 

 birds. 



The nest entrance in a creek bank is 2 feet below the 

 surface of the ground, some 9 feet above the bed of a trickling 

 stream, though with the stream not immediately below the 

 entrance. By this arrangement the young birds are able to 

 essay their first flight without danger. Judging by the 

 remains of old vegetable matter at the base of the nest, the 

 hollow has been used in a previous year for the purpose of 

 nesting. 



The nest appears to me a wonderful piece of architecture, 

 when it is considered that the whole is built in the dark. 



Nest. — A rounded structure made of grass and bark, open 

 at or near the top. It is placed at the enlarged eud of a 

 drill in the bank of a creek, or in the hollow of a tree. 



Ecjgs. — Three to five, white. Length, 0.65 inch; breadth, 

 0.55 inch. 



