Serpentiform Apodals.- 



-FISHES.- 



-CONGEROIDS. 



141 



Family IV.— SYMBKANCIIS {Symhrmi-IiUkc). 



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. Tlie pectorals 

 and other tins are eitlier wholly absent, or are very 

 scantily developed. Some members of the family 

 have scales partially distiibuted on the body ; others 

 are quite scalelcss. 



The gencr.1 are — Ampliipnous ; Ophhternon; S^irJ/ranchfi ; 

 MonopUrus ; and CheUabranchus (liicluirdsun). 



The species are not numerous, jnd are confined to 

 the southern seas. One example of Cheilohraachiis 

 was taken by Sir James Clark Hoss in the high south- 

 ern latitude of 72°. 



There are peculiarities in the branchial system of 

 some of tliese fishes, which are deserving of notice. 

 The Cuchia of the Ganges [Ampliipnous cuchia) has 

 four pairs of gill-arches ; but the first pair is united by 

 uuicous 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- 

 lined 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, 

 huks in marshy holes, and is truly amphibious in 

 respect of its respiratory organs. 



jMonoptcrus hixs three pairs of gills ; and Ophisternon 

 and Sijinbrnnchus four pairs. A Alonopterus inhabits 

 the streamlets and estuaries of Chusan, where it preys 

 on smaller fishes, and is easily captured by a liook 

 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 [Congrida). 

 Plate 2, fig. 7. 



The Conger family are, like the MunTnoids, 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 wliich 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 dor.sal 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 — Mtirceucsox ; Conrjer or Cunfjrus ; Kdta- 

 soma ; C'onrfermuiccita ; and Uroconr/cr. 



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 

 Jerse}-, where they form a considerable part of the fish 

 exposed in the fish-market of St. Ilcliers. 



Family VI.— GYMNOTIDS {Gijmnotkla). 

 Plate 2, fig. 11. 



Tiie Gymsotid-s inhabit the rivers and fresh-water 

 lagoons of tropical America, and are Malacopteroun 

 Apodals, with joiiUed fin-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 tins (unless the long, elastic, dorsal thong of 

 Sternarehus be considered as such). In all the genera 

 the anal is well developed, and edges the whole under 

 profile, commencing close behind tlie 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 colunm. 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 

 lughly-organized molluscs. One species of Sleniopyr/us 

 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 tlie common 

 cavity of the abdomen, as is the case in the Serpenti- 

 form Apodals. The stumach has a c;ecal 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 otiiers, and none exist on the vomer. 

 In some genera the fiices of the fi.sh are elongated and 

 tubidar, with small terminal mouths ; in others the 

 jaws arc abbreviated and the gape wider. 



Tlie genera are — Cymnolus; Campus; Stcmojiiffjvs ; lihawph- 

 iciithjs ; and Sternarehus. 



A Carapus of the island of Trinidad is termed 

 locally the "Cutlass-fish." The Sternarehus here 

 figured must not be confounded with the Mormyrus 

 o:ci/r/iinchus, or sacred fish of Thebes and i\Iemphis, to 

 be hereafter mentioned. None of the Gymnotids, as 

 the name denotes, have fins on the back, but the elastic 

 whip-thong of the Sternarehus has been considered as 

 the reijresentativo of a dorsal. It lies in a groove run- 

 nhig along the back, wherein it is generally giuod 



