PRELIMINARY CLASSIFIED NOTES 135 



bated chiefly by day and the male by night, changing places about 9 P.M. The 

 kittiwake is a late breeder, and few eggs are laid before the end of May or early in 

 June in the British Isles. Hantzsch estimates the incubation period at 21-24 

 days, and Naumann at three weeks, but an egg placed in an incubator hatched 

 on the 26th day (W. Evans). Only a single brood is reared during the season. 

 [F. c. B. j.] 



5. Food. Principally small fish and their ova, also surface crustaceans 

 (cf. Collett and Nansen, N. Polar Expedition Scientific Results, 1900, vol. i. pp. 26, 47 ; 

 and Collett, Bird Life in Arctic Norway). Saxby found fresh-water algae and some 

 beetles in the stomachs of specimens he shot (Birds of Shetland, p. 330). The 

 young are fed on crustaceans and small fish (Naumann, Vogel Mitteleuropas, xi. 

 290) by both parents, [p. B. K.] 



The following species and subspecies are described in the supplementary chapter 

 on "Rare Birds": 



Sabine's Gull, Xema sabini (Sabine). 



Rosy or wedgetailed-gull, Rhodostethia rosea (Macgillivray). 



Bonaparte's gull, Larus Philadelphia Ord. 



Adriatic gull, Larus melanocephalus Temminck. 



Great blackheaded-gull, Larus ichthydetus Pallas. 



Yellow-legged or Mediterranean herring-gull Larus argentatus cachinnans, 



PaUas. 

 Ivory gull, Pagophila eburnea (Phipps). [F. c. B. J.] 



