s_) is found in Greece.

The _Clarias_ and _Heterobranchus_ of Africa and south-eastern Asia have
an elongate, more or less eel-shaped body, with long dorsal and anal
fins, and are known to be able to live a long time out of water, being
provided with an accessory dendritic breathing organ situated above the
gills. Some species live in burrows during the dry season, crawling
about at night in search of food. The common Nile species, the "Harmoot"
(_Clarias lazera_), occurs abundantly in the Lake of Galilee and was
included in, if not chiefly aimed at, by the Mosaic law which forbade
the Jews to eat scaleless fishes, a prohibition which has been extended
to eels in spite of the obvious presence of minute scales in the latter.

The _Saccobranchus_ of India and Ceylon, a genus more nearly related to
_Silurus_, have also an accessory organ for breathing atmospheric air.
It consists of a long sac behind the gill-cavity, extending far back on
each side of the body under the muscles.

In the majority of the _Siluridae_, called by A. Gunther the
_Proteropterae_, a section extremely numerous in species, and
represented throughout the tropics, the dorsal fin consists of a
short-rayed and an adipose portion, the former belonging to the
abdominal vertebral column; the anal is always much shorter than the
tail. The gill-membranes are not confluent with the skin of the isthmus;
they have a free posterior margin. When a nasal barbel is present, it
belongs to the posterior nostril. This section includes among many
others the genus _Bagrus_, of which the bayad (_B. bayad_) and docmac
(_B. docmac_) frequently come under the notice of travellers on the
Nile; they grow to a length of 5 ft. and are eaten.

Of the "cat-fishes" of North America (_Amiurus_), locally called
"bull-heads" or "horned-pouts," with eight barbels, some twenty species
are known. Some of them are valued as food, especially one which is
abundant in the ponds of New England, and capable of easy introduction
into other localities (_A. nebulosus_). Others which inhabit the great
lakes (_A. nigricans_) and the Mississippi (_A. ponderosus_) often
exceed the weight of 100 lb. _Platystoma_ and _Pimelodus_ people the
rivers and lakes of tropical America, and many of them are conspicuous
in this fauna by the ornamentation of their body, by long spatulate
snouts, and by their great size.

The genus _Arius_ is composed of a great number of species and has the
widest distribut