194 



7 he Irish Naturalist. 



[September, 



I was very much struck with admiration at the appearance 

 of the " bare zone" when I first discovered it in a well-marked 

 specimen. But its great interest depends on the fact that it 

 affords a clue as to how the " lining shells " were actually 

 deposited in the bottom and along the sides of the nest. I 

 think it is almost conclusive that they have been picked away 

 from the mouth of the nest, and dropped or pushed into it, 

 and not carried for any distance by the bird in its beak, as one 

 might first perhaps anticipate. 



<>". /. 



FIGURE 2.— Diagrammatic representation of a vertical section of the 

 nest of Sterna minuta in the second or finished stage. — C. J. P. 



Half natural size. 

 1.— Lining shells. 



2. — Lining shells reaching month of nest. 

 3.—" Bare zone" or " girdle." 

 4.— Shingles outside the "zone." 

 5. — Under surface sand. 

 6' 6" 6'". — Three Eggs in position in nest. 



When we think of the ver3Mrregular shape, and the slippery 

 nature of broken shells it at once becomes manifest that it 

 would not be conducive to the comfort of the bird to earn' these 

 for any distance in its beak. I have never seen terns with 

 anything but food of some kind (fish or shrimps, &c), in 

 their beaks, at all events when flying. 



Another interesting fact about the "bare zone " is that it is 

 liable to great variation with regard to distinctness. In some 

 cases it was very feebly marked, and in others almost absent. 

 The latter condition was often associated with the fact that the 



