STERNA FLUVIATILIS. 



(THE COMMON TERN.) 



Sterna fluviatilis, Naum. Isis, 1819, p. 1847-48 ; Sharpe & Dresser, B. of Eur. pt. 8 (1871) ; 



Saunders, P. Z. S. 1876, p. 649 ; Scully, Str. Feath. 1876, p. 203 ; David & Oust. Ois. 



de la Chine, p. 525 (1877) ; Hume, Str. Feath. 1879, p. 116 (List B. of Ind.). 

 Sterna hirundo, Linn, apud Blyth, Cat. B. Mus. A. S. B. p. 292 (1849) ; Jerdon, B. of Ind. 



iii. p. 839 (1864) (errore nirundo). 

 Sterna senegalensis, Sw. B. of W. Africa, ii. p. 250 (1837). 

 Sterna wilsoni, Bonap. Comp. List, p. 61 (1838). 

 Sterna gracilis, Gould, apud Legge, Str. Feath. 1875, p. 376. 

 Hirondelle de mer, Pierre-Garin, Burfon; Sea-Swallow, Picket, Spurre, Gull-teaser, pop. in 



England ; Andorliina do Mar, Portuguese. Balakchi, lit. " the Fisher," Turki (Scully). 



Adult male (N. America). Wing 10-3 inches; tail 5-1 (depth of fork 2-4), outer feather 1-0 longer than the penul- 

 timate ; tarsus 0-81 ; middle toe 07, its claw (straight) 0-3 ; bill to gape 1-95, at front 1-5. " Length 14-0 : 

 weight 3 - 7 oz." (Scully, Tarkand) . 



" Females. Length 13'5 to 14-1 inches ; wing 10-5 to 10-6, expanse 30-5 to 32-0 ; tail 5-4 to 5-9 ; tarsus 0-75 to 0-85 ; 

 bill from gape 1-85 to 2-0 : weight 3-6 to 4-4 oz." (Scully.) 



Breeding-plumage (N. America). Iris brown ; bill coral-red, the tip of the upper mandible blackish as far back as 

 the gonys-angle of the lower ; extreme tip of lower mandible dusky ; legs and feet coral-red, claws black. 



Head, nape, and forehead with the lores to the level of the lower edge of the eye black ; lower part of the lores, face, ear- 

 coverts, and upper throat pure white, passing imperceptibly on the fore neck into the very pale greyish of the 

 under surface, which changes again on the abdomen and under tail-coverts into pure whj.te ; hind neck, back, 

 scapulars, and wings pale bluish grey, lightest on the hind neck ; upper tail-coverts and central tail-feathers pure 

 white, remainder tinged with light grey on the outer webs, those of the outermost feathers being much darker 

 than the rest ; secondaries and two inner primaries tipped with white ; primaries dark grey, the 1st with the 

 inner part of the inner web white, the next four, as in other species, with the white running out in a point into 

 the dark colour of the tips ; the outer webs and those of the primary coverts " frosted " with silvery greyish. 



The under surface appears occasionally to be pure white. 



Winter plumage. Bill black, tinged with reddish at the gape. 



(Cape of Good Hope.) Back as in summer ; head with the forehead and anterior portion of lores white ; under 

 surface white. 



Young : nestling (Bomney Marsh : Mus. Saunders). Head and upper surface warm creamy buff ; throat blackish, 

 sharply defined against the white under surface ; crown marked with three lines of black spots ; hind neck and 

 back patched with black down the centre ; wings with black spots ; a group of blackish spots on the side of the 

 rump, where the ground-colour is paler than on the back. Legs and bill yellow, the latter tipped with black, and 

 measuring 0'43 inch at front. 



In first plumage. The forehead and front of the crown with the anterior portion of the lores are white, the top of the 

 head, occiput, and nape blackish brown, descending to the cheeks behind the eye, and passing round in front of 

 it ; hind neck white ; back brownish grey, the feathers tipped with white, and marked with irregular pencillings 

 of brown near the margins. 



Immature (2nd year ?) (October till April, Trincomalie). Iris brown ; bill reddish black, reddish at the base of the 

 lower mandible, extreme tip pale ; gape and palate red ; legs and feet dusky orange. In one April specimen the 



