STERNINiE. STERNA. 
229 
The Terns, not inaptly compared to Swallows, are re- 
markable for their gliding, hovering, desultory, wavering, 
and buoyant flight, their screaming cries, social disposi- 
tion, and irritable temperament. They deposit on the 
bare sand their light-coloured and clarkly-spotted eggs, de- 
fend them and their young with pertinacity ; feed on small 
fishes, Crustacea, and insects, which they procure by ho- 
vering over the water, and dipping into it. They walk 
very awkwardly on account of the shortness of their feet. 
The plumage of the sexes is alike, but the young are 
mottled, and do not acquire their permanent colours until 
the third year. 
GENUS CXLYI. STERNA. TEEN. 
Some Terns have the bill stronger than others, as might 
be expected in an extensive genus, yet without presenting 
characters by which they might with propriety be generically 
distinguished. They are all of small size, with the body 
slender, the neck rather short, the head ovate. Bill about 
the same length as the head, nearly straight, tapering, finely 
pointed ; upper mandible with the dorsal line slightly arched, 
the sides sloping, the edges sharp and inflected, the tip very 
slender ; the nasal groove rather long, with a faint ridge 
and groove extending obliquely to the edge ; lower mandible 
with the angle very narrow, the dorsal line straight, the sides 
convex, the edges sharp, the tip very acute. Palate with 
three longitudinal ridges ; tongue slender, tapering, papil- 
late at the base, horny and slit at the point ; oesophagus 
very wide and thin ; stomach muscular, with round tendons, 
and dense prominently rugous epithelium ; intestine of mo- 
derate length and width ; coeca very small, cylindrical. 
Nostrils basal, oblong, direct, pervious. Eyes of moderate 
size. Apertures of ears moderate. Feet small, tibia bare 
below ; tarsus very short, compressed, anteriorly scutellate ; 
toes sma 1, slender, the first extremely small, the third 
longest, all scutellate, the anterior connected by reticulated 
webs, of which the inner is more deeply emarginate ; claws 
arched, compressed, slender. Plumage close, blended, very 
