FISHES 



137 



degree. A notable example is that of the John Dory 

 (Zeus }aber\ whose mouth is practically telescopic, shooting 

 forward to grasp prey at a distance with an ease and 

 rapidity recalling the slide of a trombone. 



The mouth may be placed centrally in the front of the 

 head, as seen in most fishes, or arranged in a downward- 



Lampreys 



pointing direction, a device very common in bottom- 

 feeding species such as the Skate (Raia), Dogfish {Scylio- 

 rhinus\ Sturgeons (Aapenser), etc. The large majority of 

 fish are virtually living trawl or tow nets, engulfing the 

 prey whole and sometimes taking in all kinds of extraneous 

 matters such as stones or weeds in an indiscriminate 

 fashion. Such fish have, as a rule, feeble dentition, teeth 



