264 PISCES. 



Leptocephalus, Penn. 



The branchial aperture before the pectorals^ body compressed like 

 a riband^ head extremely small, with a short and somewhat pointed 

 snout; pectorals almost imperceptible, or totally wanting; the dor- 

 sal and anal hardly visible, and uniting at the point of the tail. The 

 intestines occupy but an extremely narrow line along the inferior 

 edge. 



L. morisii, Gm.; Lacep. II, iii, 2, inhabits the coast of France 

 and England. Several other species, hov/ever, are found in the 

 seas of hot climates, all of them as thin as paper and transpa- 

 rent as glass, so that even the skeleton is not visible. The pro- 

 found study of their organization is one of the most interesting 

 to which travellers can devote themselves. 



Ophidium, Lin. 



The anus, as in Aguilla properly so called, far behind; the dorsal 

 and anal fins united with that of the tail, and terminating the body 

 in a point; the body so elongated and compressed that it has been 

 compared to a sword, and invested like that of an Eel with small 

 scales planted in the thickness of the skin. The Ophidii, however, 

 differ from Eels in their well cleft branchiae, which are furnished 

 with a very apparent operculum and a membrane with short rays. 

 Their dorsal rays are articulated, but not branched. 



Ophidium, Cuv. 



Two pairs of small cirri under the throat, adhering to the point 

 of the hyoid bone. Some of them are found in the Mediterranean. 



O. barbatum, Bl., 59. Flesh-coloured; dorsal and anal bor- 

 dered with black; the anterior cirri shortest; greatest length 

 from eight to ten inches. 



O. Vassalli, Risso. Brown; no edging on the fins; cirri equal- 

 The stomach of these fishes is a thin oblong sac; their intes- 

 tines, which have several flexures, are without caeca, their oval, 

 large and very thick natatory bladder is supported by three pe- 

 culiar bones suspended under the first vertebrae, the middle one 

 one of which is moved by its proper muscles. Their flesh is 

 good. 



O. brevibarbe, Cuv. A third species from Brazil; brown, 

 with shorter cirri. 



