ZOOLOGY. 165 



branchial orifice or spiracle, single, and situated beneath 

 the throat. 



4. Sphagebranchus. Body Eel-shaped ; pectoral fins want- 



ing ; spiracles two, situated beneath the throat. 



This differs from the last genus, in possessing two spiracles. 



5. Monopterirs. Monoptere. Body Eel-shaped ; nostrils 



situated beneath the eyes ; caudal fin distinct. 



6. Gymnotus. Gymnote, or Electric Eel. Head furnish- 



ed with lateral opercula ; on the upper lip two tenta- 

 cula ; gill-membrane, composed of five rays ; body 

 compressed ; in most species the dorsal fin is wanting, 

 but such possess a narrow fin beneath4 



One of this genus, G. electricus, possesses the power of 

 benumbing any animal it comes in contact with, by communi- 

 cating to it an electric shock ; by the exertion of this power, 

 it stuns such small species as approach it, and then 

 devours them. 



7. Odontagnatus. Month furnished with a strong moTeable 



lamina or process, on each side of the upper jaw ; gilU 

 membrane five rayed. 



8. Comephoi^us. Head large, with a compressed snout ; 



mouth large, with small teeth • body elongated, com- 

 pressed ; the second dorsal fin furnished with long 

 naked rays. 



M 3 



