BONY FISHES AND GANOIDS. 495 



cosmopolitan in distribution. Congers are found at moderate depths on rocky 

 bottoms, and are extremely voracious, taking at night almost any kind of bait. 

 Eight feet is not an uncommon length for one of these eels. There are also 

 deep-sea congers, such as Synaphobranchus and Saccopharynx, living at depths 

 down to two thousand fathoms ; the former being characterised by the union 

 of the gill-openings to form a median slit on the under surface of the fore-part 

 of the body, and the latter by the soft and spongy texture of the flesh of the 

 body. An allied group is formed by the numerous tropical species of 

 Ophichthys, in which the nostrils are situated in the lips, and the extremity of 

 the tail is free and finless. 



There are many other generic representatives of the Murcenidce, but we 

 pass on to briefly notice the small family of the Symbranchidce, which takes its 

 name from the gill-openings forming a transverse slit on the 

 lower surface. In these eels the median fins are wanting, Family 



and the paired fins rudimental, while the margin of the Symbranchidce. 

 upper jaw is formed solely by the premaxillse. The air- 

 bladder, too, is wanting ; but ducts are present to the reproductive organs. 

 Most of the members of the family are fresh-water forms from Tropical 

 America and Asia, but the Tasmanian and Australian genus Chilobranchiis 

 is marine. The Indian Amphipnous in which the gills are much re- 

 duced is remarkable for the possession of an additional breathing-organ 

 in the form of a lung-like sac on each side of the body close behind 

 the head. 



The third and last family of the section is represented by certain fresh- 

 water eels from Tropical America, which are arranged in five genera. From 

 the Murcenidce these eels may be distinguished by the 

 absence or rudimental condition of the dorsal fin, the great Family 



elongation of the anal, and the general absence of the caudal, Gymnotidce. 

 fin, the tail terminating in a point, and being as fragile as 

 that of the blind-worm. The vent is placed close to the throat, the repro- 

 ductive organs have ducts, and the pectoral girdle is connected with the skull. 

 The chief interest of this family is concentrated on the electric eel (Gymnotus 

 electricus), from the fresh-waters of the Guianas and Brazil, which attains a 

 length of six feet, and is provided 

 with electric organs very similar 

 in structure to those of the electric 

 ray described in the sequel, and 

 capable of inflicting equally power- 

 ful shocks. Most books on natural 

 history copy from Humboldt a 

 wonderful account of the capture 

 of these eels by means of horses 

 driven into the waters they fre- 

 quent, but there is only too much 

 reason to believe that the whole Fig. 25. ELECTRIC EEL. 



story is a pure fiction, although not 



an intentional one, on the part of the illustrious traveller. It is high 

 time that it should be forgotten. 



