1. HYDBOCHELIDON. '19 



jRendall, Ihis, 1892, p. 230 (Gambia) ; Biittihofer, C. R. ii. Cong 

 Oni. Intern, ii. p. 175 (1892 : Liberia) ; Fatio ^ Studer, Cat. 



distrib. Ois. Suisse, pp. 04-65 (1892) ; Lilford, Col. Fig. Brit. B. 



pt. xxviii. (1894) ; Collett, Norges Fugle/., Nyt Mag. f. Naturv. 



Bd. XXXV. p. 318 (1804). 

 Viralva nigra, Steph. in Shaw's Gen. Zool. xiii. pt. 1, p. 167 (1826). 

 Ilydrochelidon obscura, Brehm, Vdg. Deutschl. p. 795 (1831). 

 Hydrocbelidon nigricans, Brehm, Vog. Deutschl. p. 795 (1831). 

 Plydrochelidon nigrum, Bjy.Comp. List B. Eur. ^- N. Am.^. 61 (1838). 

 Ilydrochelidon fissipes, Bp. Cat. Ucc. Eur. p. 77 (1842) ; Gray, Gen. 



B. iii. p. 060 (1846) ; Licht. Nomencl. Av. p. 98 (1854) ; Bp. C. 



B. xlii. p. 773 (1856);' J«m6. et B.-Lapomm. Rich. Orn. Fr. 



p. 399 (1859) ; Salvin, Ibis, 1859, p. 3G5 (Lake Djendeli) ; Grag, 



Cat. Brit. B. p. 243 (1863) ; Salvad. Ucc. Sard. p. 123 (1864) ; 



Antinori, Cat. Descr. Ucc. p. 115 (1864 : Lower Egypt) ; Filippi, 



Viagg. Pers. p. 352 (1865 : Enzeli) ; Blasius, J. f. 0. 1866, 



p. 82 ; DegL Sr Gerbe, Orn. Eur. ii. p. 465 (1867) ; Loche, Expl. 



Sc. Alger., Ois. ii. p. 205 (1867) ; Doderl. Avif. Mod. e Sicil. p. 243 



<1869) ; Drake, Ibis, 1869, p. 154 (Marocco) ; Droste, Vogelw. 



Borkum, p. 335 (1869) ; Fritsch, Vog. Eur. p. 462, tab. 54. fig. 6 



(1870) ; Sharpe, Ibis, 1870, p. 488 (Fantee) ; Finsch, Tr. Z. S. Vi\. 



p. 305 (1870 : Zoulla) ; Salvad. Faun. Ital, Ucc. p. 284 (1871) ; 



Saund. Ibis, 1871, p. 399 (Spain) ; Shelley, B. Egypt, p. 300 



(1872) ; A. B. Brooke, Ibis, 1873, p. 346 (Sardinia) ; 'Heugl. Orn. 



N.O.-Afr. Bd. ii. pt. 2, p. 1445 (1873) ; Antin. ^ Salvad. Viagg. 



Bogos, p. 154 (1873 : Anseba, 4000 ft.) ; Irby, Orn. Str. Gtbr. 



p. 212 (1875); Menzbier, Bull. Mosc. Iviii. p. 136 (1883: Volga 



to Oka, breeds) ; Frivaldsky, Av. Hung. p. 180 (1891). 

 Hydrocbelidon pallida, Brehm, Naum. 1855, p. 295 ; id. Vogelf. 



p. 350 (1855). 

 Hydrocbelidon obscura, Brehm, Naum. 1855, p. 295; id. Vogelf. 



p. 350 (1855). 

 Sterna minuta, Feilden, Zool, 1886, p. 487 (error ; corrected, id. op. cit. 



1887, p. 73 : Faeroes). 



Adult male in nuptial plumage. Head and neck black ; mantle, 

 tail and wings slate-grey, inclining to white on the edge of the 

 carpal joint ; shafts of primaries dull white, and the webs on each 

 side dark slate-grey, except when new and frosted ; breast and 

 abdomen dark lead-colour; vent and under tail-coverts white; 

 under wing-coverts and axillaries pale grey : bill black ; feet 

 reddish brown, smaller and with less indented webs than in the 

 two preceding species. Total length 9-6 inches, culmen 1*25, 

 wing 8-5, tail 4, tarsus 0-65, middle toe with claw 0-85. 



Female. Similar .to the male, with slightly paler tints. 



Adult in ivinter. After the moult, which commences in the latter 

 part of July, the forehead is white, the crown and nape are 

 mottled with dull black, the mantle and tail are paler, the under- 

 parts white, and the axiUaries the palest grey ; feet brown. 



Young. Similar to the above, but the crown and nape browner ; 

 the mantle considerably, and tho tail slightly, mottled with brown ; 

 a pink tinge sometimes on the underparts ; feet clay-brown. 



Nestling. Fawn-colour, broadly marked with black on the upper 

 parts ; beneath pale clove-brown, darker on the throat. 



c2 



