ISir.J GENUS HYDRARGIRA. 129 



Scales* The scales are of a middling size; in gene- 

 ral they are rounds and marked with concentric lines, the 

 lines of the opercula and preopercula scales are a Jittle less 

 distinct; all the scales of the body are crossed by lines of 

 black points, which present the appearance of rhombic 

 figures: these lines, in some of the species, are found, on 

 a close examination, to be composed of a series of small 

 tubercles, each one, in the males only, terminated in a 

 point. 



Head. The head is large, and supports the snout ho- 

 rizontally. 



Gill-covers. Each operculum is composed of three 

 pieces; the inter operculum is very small. 



Nostrils. The nasal apertures are two on each side, 

 situate between the eyes, and the tip of the snout. 



Eyes. The eyes are pretty large, and seated at the 

 summit of the head. 



Lips. The lips are small in front, more fleshy on the 

 sides. 



Teeth. The teeth oHhtjaws are disposed in several 

 rows, those of the first row longer than the rest; the supe- 

 rior throat teeth are situate on two tubercles, the lower 

 teeth are placed at the junction of the branchial arch; the 

 throat teeth are often obtuse. 

 • Tongue. The tongue is distinct. 



Mucous ducts. A series of these ducts open upon 

 the head, at the end of the snout, and on the preopercula, 

 below the scales. 



Lateral line. The lateral line is very faintly indi- 

 cated. 



Fins. Uli^Jins are seven in number; each ventral 

 Vol. I. I 



