F. B. KIRKM AN: VARIATION IN NESTS OF TERNS. 81 



The fourth type was of a somewhat transitory nature. 

 It was represented by three nests placed on the beach 

 in the high- water mark seaweed, the one photographed 

 (Fig. 5) being enHvened, accidentally, perhaps, with a 

 crab's claw and a cork. These builders showed more 

 originality than discretion, two of the nests being des- 

 troyed by the sea : one of the eggs, in an unbroken state, 

 going to form part of the stranded drift. 



Fig. 4. — Arctic Tern sitting on Nest in Sand. 



The remaining four nests were highly instructive, being 

 a combination of the first two types. They were all 

 paved with pebbles, to which bits of bent (Fig. 6*), and in 

 one case a complete outer circle of bent, were added. 



It is worth noting that there was no definite relation 

 between site and material, except in respect to the two 

 nests in the bent, which were made of bent, and those in 

 the seaweed. The pebble-paved, the bent nests, and 



* This figure will appear in the second instalment of this article. 



