THE EEL FAMILY. 



397 



compressed, pointed, gape small ; jaws very narrow ; lower jaw longest ; 

 both jaws furnished with a narrow brush-like band of small teeth ; 

 throat- teeth setaceous. Various mucus-pores about the mouth and 

 head, amongst which there is an ear, or auditory aperture, on each 

 side; gill-opening, a small orifice immediately before, and rather 

 below, the pectoral fin. Scales rather small and delicate, oblong. 

 Vertebrae 113. Four distinct openings in vent, the foremost leading 

 upwards to the intestine, the hinder one backwards to the bladder, 

 and a lateral slit on each side communicating with the abdomen, for 

 the exit of the roe. Colour : prevailing hue of all the upper surface 

 dark olive-green ; sides lighter ; belly white. When obtained from 

 pure streams the colours are clear and bright, and the fish is then 

 called a Silver-Eel ; when from muddy waters the colours are brown 

 and dusky. The fin-rays are not easily counted, owing to the thick- 

 ness of the skin. (For engraving of skull, &c., and distinguishing 

 peculiarities, see p. 378.) 



HEAD OF SHARP-NOSED EEL. 



