MUR^ENID^E. 239 



Family, VI— MURtENID^, Mutter. 



Body elongated, cylindrical or band-shaped : the humeral arch not attached to 

 the skull. The branchial openings in the pharynx may be wide or narrow slits. 

 Margin of the upper jaw constituted anteriorly by the premaxillaries* which 

 are more or less coalescent with the vomer and ethmoid, while laterally the 

 sides of the upper jaw are formed by the maxillaries which are furnished 

 with teeth. Vertical fins, when present, confluent or separated by a projecting 

 tail : pectorals present or absent. Ventrals absent. Scales, when present, 

 rudimentary. Vent may be situated close to the base of the pectoral fins, or a 

 long distance posterior to the head. The heart may be just, or far behind the 

 gills. Stomach with a blind sac. No pyloric appendages. Ovaries destitute of 

 oviducts. 



Cuvier placed the eel- shaped fishes (including the tropical Symbranchidce) in 

 one Family, Murjsnidji, while they have likewise been termed Apodal, owing to 

 a deficiency of the ventral fins, which latter phenomenon is perceived in species 

 of various other families, for being the last evolved or most immaterial among 

 the fins, they are most commonly absent. Thus in Ceylon and China the genus 

 Channel among the Ophiocephalida3 is distinguished from Ophiocephalus by the 

 absence of the ventrals. The Indian Siluroid genus Ailichthys differs from Ailia 

 due to the same cause. Genus Neochanna differs from Galaxias for a similar 

 reason. In the Cyprinodontidse, Tellia is a Cyprinodon without ventrals. 

 Apua among the Cobitidinse is closely allied to Acanthophthalmus but has no 

 ventrals, while the chief distinction between the Clupeoids Opisthopterus and 

 Pellona is that the former is without ventrals while the latter has very small 

 ones. CalamoicMhys is Polypterus without ventrals. Doubtless in some instances 

 this deficiency of the fin may be an individual monstrosity or a local race, as I have 

 observed (vol. i, p. 245) as regards Gasterosteus pungitius. It may, perhaps, be a 

 sexual character, thus Troschel (Wiegm. Arch. 1871, pp. 276-280) remarked upon 

 having received a female Siluroid of Copidoglanis brevidorsalis destitute of these 

 fins. It may be present in the young as Stromateus niger, but be lost with age, 

 and absent from other species of the same genus. Attention has likewise been 

 drawn to the fact "that in numerous groups of fishes which live in mud, forms 

 occur, devoid of, or with only rudimentary ventral fins" (Giinther, Annals and 

 Mag. Natural History, 1867, xx, p. 308). 



Eels by some authors have been looked upon as, sometimes at least, herma- 

 phrodites. But Syrski, Dareste, and others have observed upon what they deem 

 to be the male organs of the eels. A number of larval fishes have been termed 

 Leptocephali or " Glass eels." Some of these may be forms in which develop- 

 ment has been arrested in an early stage of existencef, the fishes never attaining 

 the perfect state, but such are generally, if not invariably, in Great Britain 

 confined to the salt water. It is an error however to consider them as usually 

 restricted to some distance out in the ocean, as along the coasts of the Bay of 

 Bengal they are innumerable and to be found close in shore. 



The Family Murjenid.5: are divisible into two groups : (1) Those in which the 

 branchial openings in the pharynx are wide slits, Murcenidce platychistce, among 

 the genera composing which is Anguilla. (2) Those having the branchial 

 openings in the pharynx as narrow slits, Murcenidce engyschistce, an example of 

 which we possess in the genus Murcena. 



* Meckel, Peters, and Jacoby consider the lateral portion only of the upper jaw is formed 

 by the maxillaries, the front part being the prcmaxillary which coalesces with the vomer and 

 ethmoid, but may always be distinguished. 



t Carus, Brit. Asso. 1860, Gill, 1864. 



