Serpentifobm Apodals. FISHES. Congeroids. 
141 
Family IV.— SYMBRANCHS {Syrribranchidas). 
This family name has reference to the two outlets 
of the gills into a single external orifice situated under 
the throat, either with or without a membranous par- 
tition coming to the lip of the opening. The pectorals 
and other fins are eitlier wholly absent, or are very 
scantily developed. Some members of the family 
have scales partially distributed on the body ; others 
are quite scaleless. 
The genera are — Amphipnous ; Ophisternon ; SynibrancJius ; 
Monopterus ; ani Cheilobranchus (Richardson). 
The species are not numerous, and are confined to 
the southern seas. One example of Cheilobranchus 
was taken by Sir James Clark Ross in the high south- 
ern latitude of 72°. 
There are peculiarities in the branchial system of 
some of these fishes, which are deserving of notice. 
The Cuchia of the Ganges {Amphipnous cuchia) has 
four pairs of gill-arches ; but the first pair is united by 
mucous membrane to the succeeding one, and the 
fourth pair is similarly bound to the third one, the first 
and fourth being unprovided with gills, which are con- 
fined to the second and third pair of arches ; and the 
branchial processes are long, slender, fringe-like fila- 
ments. These rudimentary gills are aided in their 
function of aerating the blood by a large air-bag on 
each side of the head, having a cellular and very vas- 
cular interior, and communicating with the mouth by 
an opening before the first branchial arch. This fish, 
which is of sluggish habits and very tenacious of life, 
lurks in marshy holes, and is truly amphibious in 
respect of its respiratory organs. 
Monopterus has three pairs of gills ; and Ophisternon 
and Symbranchus four pairs. A Monopterus inhabits 
the streamlets and estuaries of Chusan, where it preys 
on smaller fishes, and is easily captured by a hook 
baited with an earth-worm. It is a favourite food of 
the inhabitants of that island, and is preserved by them 
alive in large jars of fresh water until needed. 
Family V. — CONGEROIDS (Congridce). 
Plate 2, fig. 7, 
The Conger family are, like the Miirsenoids, fierce 
and pugnacious fishes, and being better armed on the 
jaws, many of them with acute lancet-shaped teeth, 
and having moreover the aid of tails which are in 
some degree prehensile, and can be wrapped round 
a man’s arm or hook on to the gunwale of a boat, 
they fight with more danger to their captors. The 
first movement, therefore, of the fisherman, when he 
has dragged one out of the water, is to batter and dis- 
able it by blows from a handspike or other convenient 
truncheon. This family of fishes have a dorsal fin 
reaching forwards to the head, a naked and scaleless 
skin, and for the most part a tapering, compressed tail, 
at the point of which the dorsal and anal meet. Pec- 
toral fins are present in some, but wanting in other 
species. The snout is generally elongated, and the 
mandible shuts in behind the upper jaw. A labial 
cartilage is developed in the lips, and many slender 
ribs spring from the vertebral column, even in the tail. 
The genera are — Murmncsox ; Conger or Congrus ; Netia- 
soma; Congennurmna ; and Uroconger. 
A prodigious quantity of the common Congers are 
stated by Col. Montagu to be taken on some banks on 
the French side of the Channel, the bait used being 
Sand-launces purchased in England. The chief British 
fishery for the Congers is carried on along the Cornish 
shores, and a great number so caught are sent over to 
Jersey, where they form a considerable part of the fish 
exposed in the fish-market of St. Hcliers. 
Family VI.— GYMNOTIDS (Gymnotidce). 
Plate 2, fig. 11. 
The Gymnotids inhabit the rivers and fresh-water 
lagoons of tropical America, and are Malacopterous 
Apodals, with jointed jin-rays, having the vent situated 
on the under aspect of the head. The family characters 
may be summed up as follows : — Eel-like fishes, with 
no dorsal fins (unless the long, elastic, dorsal thong of 
Stes'iiarchus be considered as such). In all the genera 
the anal is well developed, and edges the whole under- 
profile, commencing close behind the vent. In some 
members of the family the vent is farther forward than 
the eyes, and in none is it situated farther back than 
beneath the gills. The skeleton is in advance of that 
of the Serpentiform Apodals, having the scapulo-cora- 
coid arch attached to the head, instead of being as in 
that group feebly framed and appended to the fore part 
of the vertebral column. The Gymnotid skeleton also 
possesses perfect ventral ribs. The family, moreover, 
is characterized by a twofold swim-bladder, the ante- 
rior capsule of which is small, and is protected by a 
fibrous capsule. This capsule is connected with the 
acoustic organs, and is thought by Dr. Kaup to be the 
homologue of the membranous labyrinth of the more 
highly-organized molluscs. One species of Sternopygus 
has a pneumatic tube issuing from each of its air- 
bladders. The eggs of the Gymnotids are contained 
in ovarian sacs, and do not drop into the common 
cavity of the abdomen, as is the case in the Serpenti- 
form Apodals. The stomach has a ciecal projection, 
and there is a papilla behind the vent. Teeth are pre- 
sent on the upper jaw and mandible in some species, 
but wanting in others, and none exist on the vomer. 
In some genera the faces of the fish are elongated and 
tubular, with small terminal mouths ; in others the 
jaws are abbreviated and the gape wider. 
The genera are — Gymnotus; Carapus; Sternopygus; Rhamph- 
Ichthys ; and Sternarchus. 
A Carapus of the island of Trinidad is termed 
locally the “ Cutlass-fish.” The Sternarchus here 
figured must not be confounded with the Mormyrus 
oxyrhinchus, or sacred fish of Thebes and Memphis, to 
be hereafter mentioned. None of the Gymnotids, as 
the name denotes, have fins on the back, but the elastic 
whip-thong of the Sternarchus has been considered as 
the representative of a dorsal. It lies in a groove run- 
ning along the hack, wherein it is generally glued 
