MAKKI r.MM.i: r.urnsii MAKINK FISHES 



CHAP. 



.nd and contract regularly while the fish is alive. There is 



also usually a smaller opening from the throat, known as the 



spiracle, and situated just behind the eye. Another peculiarity 



of these fishes is the position of the mouth, which is a wide 



e slit on the flat, lower surface of the head. In other 



words, the snout projects usually to some distance beyond the 



and terminates in a point. The fin-rays in these fishes are 



rods of gristle or cartilage with very numerous joints, and in 



addition to these there is beneath the skin of the fins a layer 



of fine horny fibres. The second pair of side fins or pelvic fins 



.'. \vays placed close to the vent. The tail has a characteristic 

 form, consisting of two unequal lobes, of which the upper is the 

 longer: the spinal column is bent up at the base of the tail, and 

 continued into the upper lobe. 



;. The Bass, as example of the bony fishes. D.F. dorsal fin ; V. F. ventral 

 fin; C.F. ouul.il fin; PC. F. pectoral fin; Pv. F. pelvic fin; L.L. lateral 

 line ; G.C. gill-o.ver : N. nostrils of right side. 



Bones and scales arc the chief characteristics of the scaly 

 although in some the scales are almost or entirely absent, 

 M fr instance in the eel. The scales overlap one another like 

 the tiles of a house, and the larger part of each is imbedded in 

 kin, only the smaller hinder portion being exposed The 

 tube of the lateral line pierces a longitudinal series of special 

 scales, and to each of these scales corresponds a pore open- 

 ing into the interior of the tube. The mouth is usually at the 

 end of the snout and provided with bony jaws and teeth. The 

 gill-cover, a broad plate on each side behind the head supported 

 by bone, covers over the chamber in which the gills are contained 



