32fi PISCES. 



G^/mnotus, the true Electric Eels, have no caudal or dorsal fin, nor visible scales; moderate intestines, with 

 several Ilexiires, and numerous cceca ; stomach short, and plaited on iis inner surface. Om; Ion;;- inr-liladdi r 

 extends in a cavity of the abdomen ; the other, in two lobes, is placed over the y;ullet. round only in ijie n\ris 

 and stag-nant fresh waters of tropical America ; and the most celebrated is,— 



G. rh.-r(tir?fx, the Electric Gyninotus, called from its form the f:iectric Eel. It attains the length of fu'e or six 

 feet, and coniniiniicates shocks so powerful that men and horses have been stunned by them. This power is 

 voluntary, and can be sent in a jiarticular direction, and even throuij^h the water, the fish in which are killed, or 

 stunned, by its ^llo^ks. By gi\in^; these, it is greatly e.xhansted, and rrijuires both rest and nourishment before it 

 can renew tliern. The ininiediatr or^an of this power cxtemls alon-- llie whole under-side of the taU, occupying 

 about half its thickness. It consists of two larij;e longitudinal fasciculi above, and two smaller ones below, resting 

 on the base of the anal fin. Each fasciculus is composed of nunicrons parallel membranes, nearly horizontal, and 

 close to each other, one end being attached to the skin, and the other to the mesial jdane. They are joined by 

 numerous transverse and vertical membranes; and the canals and cells thus formed are filled with gelatinous 

 matter. The whole ajiparatus is largely supplied with nerves, [affording one strikin^^ instance of the intimate 

 coiinexi(Ui between electric or galvanic action in uiattei", and nervous action in li\ing animals.] 



Cara/'iis, has the body compressed and scaly, and the tail much narrowed. They live in the South American rivers. 



*V/tV'(//(7///.s-, h.ive the anal separated from the tail, and a caudal,— a Mift filarjirut along the back, lodged in a 

 groove, in which it is retained by tendinous threads, and reachini; the wbnie way to the tail, tt has some freedom 

 of motion, but the use of it is not known. The head is oblique, compressed, and naked, with the skin hiding tlie 

 operculum and gill-rays ; the body scaly ; the teeth small and crowded, and scarcely discernible in the middle of 

 the jaw. Like the rest of the genus, they inhabit the waters of South America. 



Gi/mnarc/ttis. — Body long and scaly; gill-opening before the pectorals ; a soft-rayi.'d fin ahmg tlie back, but no 

 anal, and the tail ending in a point ; head naked and conical; mouth small, and with a single row of cuttmg-teeth. 

 G. niloiiciis, the only known species, inhabits tlie \iie. 



LeptncepbalHs. — Gill-opening before the pectorals ; body compressed and ribb(3ndike ; head very small ; snout 

 short, and a little pointed; pectorals nearly or totally wanting ; dorsal and anal obsL-ure, but extending to the 

 point of till.' tail ; the viscera occupying a soiall cavity along the under-part of the boily. One species is fouutl in 

 the British seas. L. mon-issii, the Anglesey ^Inrris, is a very little fish, silvery, and semi-transparent, but wth 

 bri:;ht and prominent rays, and is very li\ ely in its umtions. it larks in sea-weed ; and is one of tlio.-e animals, 

 exceedingly i"are among Vert' brata, of which the irdernal structure can be seen without dissection, and its actiuu 

 understood accordingly. Other species have been found in the warm seas. 



Ophidinm, resembles the Eels in having the vent far backwards, and the dorsal ami anal meeting at the point of 

 the tail; and the body is so long and compressed, that the fish has been compared to a sword-blade. The skin 

 has mmute and buried scales, as in the liels, but the gill-openings are large, and the gill-lids have free motion ; 

 the dorsal rays arc jninril, not branched ; some have small barbulcs, others none, and some short cirri ; some aie 

 flesh-coloured, with bh.rk fins ; some brown, and some large ones are rose-colour, with brown spots. 



[The species without cirri, the 0. imbeybis of Linnaeus, has been madr a subL;(nus li\ ruvier, uiuler the name of 

 Fierasfer, in which the dorsal seems a mere fold of the skin. A siM.cinicn, almut (In ii- i)ichcs lung, has been met 

 with on the south coast of England]. 



Ammoibjtes, have the body like the former, a tin witli -iniple-jolnted rays along the b:wk, an anal fin, and a forked 

 caudal, and Ihe fins are not united ; snout slj:(i-[t-, n|i|icr jaw extensile, and :>horter tliaii the lower in the cl"S(-d 

 nioutli ; stomarh fie^liy and pointed ; no cceca, or aii-l.l.nller. They hnrrow in the sand, and are captured by 

 dig!.;iug it at low water ; and are undei'Stood to cuutnlmti; mat(.-i-ially lo tin- su]i[iort of Salnion in tin:' i-stuaries. 

 There are two species : — ,-J. ^o6mH?«, the Sand-eel ; and .-J. /«f/(rt'(7, the Sand-lance. The latter is thiekc-r in the 

 body than the former, with the intennaxillaries larger, and the dorsal commencing farther forward. 'Jln.yare 

 botlj found on tlie sandy shores of Britain. 



THE FIFTH OFvDER OF BONY FISHES. 



LOPUonRAX<_'IJlI (Fishes with their CJills in Ti'fts). 



All the fishes of the preceding four orders not only hiive a skeleton of filn-ous bones, and 

 the jaws complete and free, but then' gills are al\Miys in lilivcs or fringes, like the teeth of a 

 comb, but those of the present order, while they have the jaws complete and free, have the 

 gills not in equal laminfc along the arches, but m small round tufts, disposed along the arches 

 ni })airs,- -a structure of winch there is no instance in other fishes. These are defended l^^" a 

 large opercidum, attached lj\' nienibranes on all sides, e.\cept one small hole for allow iiu;' the 

 water to escape ; and mere vestiges of ra)'s are shown in the suljstauce of the opcrciiliiu:. 

 These fishes are also distinguished by shields or small plates, which cover the liod\ , and oltcn 

 give it an angular form. In general, they are of small size, and almost without ilesli. Their 



