468 THE LACCADIVES AND THE WEST COAST: 
is distinguishable from its three nearest allies—Sterna fluviatilis, 
Naum. (8. Airundo, Tem nee L.) ; 8. hirwndo, L, (=8. macroura 
Naum.; S. arctica Tem.; S. paradisea, Briin) and 8. longipenn’s 
Nordm,—in the much darker grey of the upper surface; in its 
longer and slenderer bill, in the upper tail coverts almost uniform 
with the back, and in the almost entirely grey inner webs to the 
tail feathers. 
This species has only hitherto* been obtained on the 
coasts of the Red Sea, northwards to about the twenty-fourth 
parallel north Lat. and southwards to the Gulf of Aden, 
where Heuglin tells us that it is more common on the African 
than on the Asiatic shore. It constitutes, therefore, an impor- 
tant addition to our Indian avifauna, the only one which our 
expedition yielded. We never saw this species on any other 
occasion. 
Of two males, the dimensions were as follows, but I may note 
that of the second male the external tail feathers were 
undeveloped :— 
Length, 14"5,12"5; expanse, 2925, 29"°5; tail from vent, 
6'°5, 4°15; wing, 99, 9°°7; tarsus, 0"77, 0"75 ; mid toe and 
claw, 1°04, 0":94; bill from gape, 2"°15 ; at front, from margin 
of feathers, 1"°55, 1":47. 
In both specimens the irides were deep brown; the legs and 
feet, Indian red, tinged in front of tarsi and toes with blackish 
dusky ; the bill was blackish, with the extreme tips, whitish horny, 
and with more or less of a reddish tinge, as if it would turn 
red ; gape and inside of mouth, deep red. 
The lores and point of the forehead, white ; the latter with a 
few black speckles ; a patch in front of the eye, black speckled 
with white; the anterior half of the crown, white tinged earthy 
or brownish grey, and with spots and blotches of brownish 
black. Feathers immediately above the eye, all the feathers 
behind the eye, the sides of the head, occiput and nape, black ; 
the posterior half of the crown blackish brown, a little min- 
gled with greyish white; an imperfect white band from the 
lores beneath the eyes; and an imperfect black stripe below 
this. 
The back of the neck, whitish; the feathers suffused with 
grey towards the tips; the whole of the back, scapulars, wings, 
tail, a moderately dark french grey, darker than in S. bengalensis, 
but not so dark as in some Bergit. The upper tail coverts, 
slightly paler; the wings, more silvery ; but the outer web of 
the first primary and of the exterior elongated tail feather, much 
* Long after this was written, Lord Walden announced in the Ibis. having pro- 
cured specimens of this species from Bombay. 
