COMMON TERN. 
17 
SD ^'-'^^sionally they are pale olive-brown. The underlying 
purplish-grey, and are always distinct. Axis, 2 -3-2 '6 
diam. 1 7-1 -85. 
the true terns, genus sterna. 
Sterna, Linn. Syst. Nat. i. p. 227 (1766). 
d'ype, probably S. flmiatilis (Naum). 
I-ike the preceding genera, the Terns have the outermost 
^' 1 -feathers much longer than the rest, and pointed. They 
, ' from Gclochelidon in having a short tarsus, which measures 
ss than the middle toe and claw, and in the case of the genus 
never exceeds the latter. The tail, according to Mr. 
°ward Saunders, is at least half, and generally more than 
“ h the length of the wing. The 'Frue I'erns are also remarkable 
■or their 
compressed and slender liill. 
'^cy aj-g \yorld-widc in their distribution, and are almost 
j '^®ively maritime in their haunts. 
ntermediate between the Caspian Terns and the genus 
is the Indian genus Seena, which has a single river- 
^unting species, Seena seena (Sykes), remarkable for its stout 
* ) which has the genys very short, and its long tail, which is 
than three- fourths the length of the wing. 
I- the common teen. STERNA FLUVIATILIS. 
Naum. Isis, 1S19, pp. 1847, 1848; Dresser, 
Lur. viii. p. 263, pi. 580 (1872) ; 15 . O. List. Brit. 15 . 
p. 180 (1883); Saunders, ed. Yarrell’s Brit. 15 . iii. p. 549 
(1884); id. Man. Brit. B. p. 631 (1889); Lilford, Col. 
Tig. Brit. B. part xx. (1891) ; Saunders, Cat. B. Brit. Mus. 
XXV. p. 54 (1896). 
turunda, Lath.; Macgill. Brit. B. v. p. 638 (1852); 
^eebohm, Blist. Brit. B. iii. p. 280 (1885). 
winw'^'^'" Males. — General colour about pearl-grey, including the 
and° scapulars, the latter white at the ends ; rump 
the inner'" white ; primary- coverts pearl-grey, with 
with whit^ more dusky ; primaries dark grey externally, 
^ e shafts, accompanied by a blacker border along its 
