418 RHYNCHOPID^ BHTNCHOPS 



773. Gygis Candida. White Noddy. 



Sterna Candida, Gmel. Syst. Nat. i, p. 607 (1788). 



Gygis Candida, Gould, B. Australia vii, pi. 30 (1848) ; Saunders, Cat. 



B. M. XXV, p. 149 (1896) ; Beichenow, Vog. Afr. i, p. 73 (1900). 

 "White Bird" at St. Helena. 



Description. Adult. — Throughout above and belowwhite, except 

 for an inconspicuous ring of black round the eye ; the shafts of the 

 primaries and rectrices more or less tinged with brown. 



Iris blue; bill black; feet black; webs yellow, and incised to 

 the first joint of the toes. 



Length about 12'5; wing 10-0; tail 3-70; tarsus -60; culmen 

 1'55. The sexes appear to be alike in plumage : possibly the rectrices 

 are longer in the male. In young birds the shafts of the rectrices 

 are rather darker. 



Distribution. — The White Noddy is found about the tropical and 

 subtropical islands of the Atlantic, Indian and Pacific Oceans. It 

 is well known at St. Helena and Ascension where it breeds, and is 

 also found about Madagascar and the Mascarene Islands in the 

 Indian Ocean. Mr. Layard met with- it on Sandy Island north- 

 east of Madagascar in 1856 (see Cape Monthly Magazine iii. 1858, 

 p. 289). 



Family III. RHYNCHOPIDiE. 



This family contains only one genus and is at once distinguished 

 by its remarkably compressed and flattened bill in which the lower 

 mandible considerably exceeds the upper one in length. Of the 

 Garrodian thigh muscles the ambiens is absent; the caeca are 

 rudimentary. 



Genus I. RHYNCHOPS. 



Type. 

 Bhynchops, Linn. Syst. Nat. 12th ed. i, p. 228 (1766) ... E. nigra. 



Bill very much compressed, especially the lower mandible, 

 which is like the blade of a paper knife, and is considerably longer 

 than the upper one ; both are truncated at the tips, and the lower 

 one is marked with oblique ridges ; nostrils irregular ovals near the 

 base of the bill in a slight depression ; wing very long, reaching 



