404 THE ANGLER-NATUKALIST. 



common Lamprey (Petromyzon marinus), in which the left- 

 hand figure represents the mouth of the fish when at rest, 

 or closed, and that on the right the same organ when open, 

 or in the act of suction the point of view in both cases 

 being from below. The small and numerous tubercular 

 teeth are also shown in the right-hand engraving, and the 

 central aperture leading by the throat to the stomach. 

 The mouth is provided with a flexible lip, which effectually 

 conceals its shape when closed. The organ of suction is 

 the tongue. 



MOUTH WHEN SHUT. MOUTH WHEN OPEN. 



As it would obviously be impossible for these fish, when 

 adhering to stones or other fixed objects (their natural 

 position), to breathe through their mouths in the usual way, 

 Nature has provided them with a breathing- apparatus dif- 

 fering from that of other species, and admirably adapted 

 to their peculiar exigencies. 



This consists of seven small apertures on each side of 



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the neck leading to seven cells, in which are situated the 



