SMALLER SOOTY TERN AT THE MOUTH OF THE THAMES. 215 
feet are webbed to the extremities, and the young are for some 
time dusky on the under parts. The reason for laying stress on 
these particulars will be shown in treating of the next species. 
STERNA ANZSTHETA (originally printed S. anethetus), Scopoli, 
Deliciz Flora et Faune Insubrice, i. p. 92, No. 72 (1786), ex 
Sonnerat’s Voyages, p. 125, pl.84, where the species is described 
as the Hirondelle de Mer de Panay (Phillipine Islands), whence it 
is sometimes called the Panay Tern, S. panayensis, Gm. (1788), &c. 
The range of this species is almost the same as that of its congener, 
whose example, as we have seen, it has followed in straggling as far 
as our Coast, but the information we possess tends to show that it 
is rather Jess oceanic in its habits, and more inclined to hug the 
shore. Jn distribution of colour it resembles S. fuliginosa, but it 
is somewhat smaller in size; the mantle and wings are decidedly 
less sooty, the white from the frontal band extends both above and 
beyond the eye, and the web between the middle and inner toes 
only extends to the last joint of the latter, and does not come 
down to the claw; the young also are light on the under parts on 
emerging from the downy stage. A woodcut of the above differences 
in the formation of the feet of the two species will be found in my 
paper on the Sternine (Proc. Zool. Soc., 1876, p. 665). 
The third species of the group is STERNA LuUNATA, Peale, U.S. 
Expl. Exped.—Birds, p. 277 (1848). It is intermediate in size 
between the other two, has a more distinctly slate-gray mantle, 
and is altogether washed with a grayish tint; the webs of the feet 
are similarly incised with those of S. anesthela, to which it is 
more closely related than to S. fuliginosa. Its range, so far as we 
know it at present, only extends from the Moluccas to the Phenix 
and Paumatu groups of the Polynesian Islands. Ido not know 
of any specimens in collections in this country, but the Leyden 
Museum, which is far in advance of our national collection in 
Laride, possesses several examples. 
The Sooty Terns have been separated generically from the true 
Terns by Wagler, and as one or other of his generic names have 
been pretty freely adopted, it may be edifying to consider them 
for a moment, for they supply an excellent sample of the way in 
which our scientific nomenclature is encumbered by useless and 
