G. STERNA. 



41 



Type. 



Haliplana, Wagler, Isis, 1832, p. 1224 S. fuliginosa. 



Ilydrocecropis, Bote, Isis, 1844, p. 179 (pt.). 

 Thalassipora, Bote, teste Riipp. Si/st. Uebers. p. 140 



(1845) S. fuliginosa. 



Melanosterna, Blyth, J. A. S. Bemj. xv. p. .373 (1846). S. ausestlieta. 



Ranrje. Cosmopolitan. 



Key to the Species* 



A. Crown black in breeding-plumage. 



a. Bell}' black ; bill and feet yellow melanog aster, p. 43. 



h. Belly white or grey. 



«', Size larger ; wing never less than 9''5 in. 



a". Forehead black to the base of the 



culmen. 



a'". Size smaller, wing less than 12 in. ; 



feet red to livid. 



rt*. Outer web of long streamers t 



white, inner web darkish grey ; 



belly white forsteri, p. 46. 



b*. Outer web of streamers grey, or — if 

 whitish — not contrasting sti-ongly 

 with the colour of the inner web. 

 «'. Inner webs of primaries not 

 edged with white to their tips. 

 a^. Upper tail-coverts white, in 

 strong contrast with the gi'ey 

 of the upper parts. 

 a'. Outer tail-feathers not much 

 ])rolonged, only exceeding 

 the next by about ^ in. . . albistriata, p. 48. 

 v. Outer tail-feathers produced 

 into streamers, exceeding 

 the next pair by more than 

 an inch, 

 fl''. Bill and feet red. 

 a^. Mantle and underparts 



dark smoky grey .... virgata, p. 50. 

 U'. Mantle and underparts 

 paler grey. 

 a^°. Outer web of strea- 

 mers very slightly 



a". Smaller; under- 

 parts grey .... tittata, p. 51. 



h^^. Larger; under- 

 parts nearly 

 white hirundinacea,'-^. 52. 



* It is hoped that this Key will prove sufficient even for the identification of 

 birds in the winter and the immature plumages ; bearing in mind that any dar 

 coloration, though diminished in those stages, is seldom wholly absent, and that 

 the colours of the bill &c. are then duller. For further details reference must 

 be made to the descriptions. 



t For the sake of brevity the outer tail-feathers when prolonged and pointed 

 are called streamers. 



