Fig. 380.—Erpetoichthys calabaricus Smith. Senegambia. (After Dean.)
The genus Erpetoichthys contains a single species, Erpetoichthys calabaricus,[163] found also in the Senegal and Congo. This species is very slender, almost eel-like, extremely agile, and, as usual in wriggling or undulating fishes, it has lost its ventral fin. It lives in shallow waters among interlaced roots of palms. When disturbed it swims like a snake.
FOOTNOTES:
[163] This genus was first called Erpetoichthys, but the name was afterwards changed by its author, J. A. Smith, to Calamoichthys, because there is an earlier genus Erpichthys among blennies, and a Herpetoichthys among eels. But these two names, both wrongly spelled for Herpetichthys, are sufficiently different, and the earlier name should be retained. "A name in science is a name without necessary meaning" and without necessarily correct spelling. Furthermore, if names are spelled differently, they are different, whatever their meaning. The efforts of ornithologists, notably those of Dr. Coues, to spell correctly improperly formed generic names have shown that to do so consistently would throw nomenclature into utter confusion. It is well that generic names of classic origin should be correctly formed. It is vastly more important that they should be stable. Stability is the sole function of the law of priority.
[CHAPTER XXXV]
SUBCLASS DIPNEUSTI,[164] OR LUNGFISHES
The Lungfishes.—The group of Dipneusti, or lung-fishes, is characterized by the presence of paired fins consisting of a jointed axis with or without rays. The skull is autostylic, the upper jaw being made as in the Chimæra of palatal elements joined to the quadrate and fused with the cranium, without premaxillary or maxillary. The dentary bones are little developed. The air-bladder is cellular, used as a lung in all the living species, its duct attached to the ventral side of the œsophagus. The heart has many valves in the muscular arterial bulb. The intestine has a spiral valve. The teeth are usually of large plates of dentine covered with enamel, and are present on the pterygo-palatine and splenial bones. The nostrils are concealed, when the mouth is closed, under a fold of the upper lip. The scales are cycloid, mostly not enameled.
