RHTKCHOP? 



93 



Fig. 21. — To show the peculiar formation of the bill. 



58. Rtiyncliops cinerascens. 



Black-tailed Skimmp:r. 



Hhi/nchojys cinerascens Spix, Av. Bras. ii. p. SO. pi. cii. 1825 i /' in locis 



ripariis flum. Amazonviui " j ; Brabom-ne & Chubb. B. S. Amer. i. 



p. 3i, no. 33S, 1912. 

 Uliynclwps nigra cinerascens Beebe. Our Search for a Wilderness, 



pp. 135, 148, 1910 (Hoorie Creek). 

 RJiynchops melanurus Swains., Cab. in Schomb. Beis. Guian. iii. p. 701 



(1848) ; Brown, Canoe and Camp Life. pp. 95. 340, 1870 ( Mt. Arrisaro, 



Upper Corentyne Eiver). 

 Bhynchops melanura Saunders. Cat. B. Brit. ^NIus. xxv. p. 150, 1890 



(River Rupiu'uni, Ouiiimee). 

 Rhynchops nigra Quelch, Timehri (2) v. p. 100, 1891 (George town). 



"The Large Scissor-bill Gull" [Quelch); "Sea-dogs" {Brown), 



Immature. General colour above blackish brown, with j^aUr 

 edges to some of the feathers ; forehead and under surface of bodv 

 white. Iris dark brown ; feet orange-red. 



Total length 445 mm., culmen 85, gonys 113, wing 380, tail 09, 

 tarsus 35, middle toe and claw 34. 



Tlie bird described was taken on the Abary River in July 1006. 



Adult male. Head, back, and wings black : tail dark brown 

 with pale edges to the feathers ; forehead, cheeks, throat, breast, 

 abdomen, and under tail-coverts white ; nxillaries and under wing- 

 coverts pale brown. 



Total length 515 mm., culmen 80, gonys 114, Ming 428, 

 tail 130, tarsus 3G. 



Adult female. Similar to the adult male, but smaller in si/e. 

 \^'ing 382. 



The de5Cri})tions of the adult male and female are taken from 

 specimen.s in tlie British ^luseum collected Ity H. AVhitely in 

 Britisli Guiana. 



Breediiifj-season. Unknown in Briti.'-li Guiana. 



jS'est. " On the sandy banks of the rivers*' {Sc/iotnhurok). 



Jlays. rnde^cribeil from Briti>h (luiaiui. 



