138 A NATURAL HISTORY OF THE SEAS 



being of little practical value, though in certain abyssal 

 forms {Choliodus and Haplostolea) they form a veritable 

 chevaux de frise barring the escape of any creature once 

 seized, and are of such excessive length that they protrude 

 in both an upward and downward direction when the 

 mouth is closed. In the Common Angler (Juophius) a 

 somewhat similar device is present, many of the teeth 

 being hinged so that the prey can slide over them and into 

 the Angler's interior, but cannot hope to retreat over 

 them and into the water beyond. Such fish as the marine 

 Barracuda have razor-edged teeth rivalling those of the 

 Sharks and capable of inflicting lethal wounds upon much 

 larger fish and even human beings. 



More discriminating fish often have quite small mouths, 

 those of the Sea Horse {Hippocampus) and the Pipe Fish 

 {Sygnathm) being typical examples. Here, however, the 

 prey being minute, virtually no teeth are required, in 

 striking contrast to those fishes habitually feeding upon 

 hard substances. The Wrasses (Labridae) commonly eat 

 crustaceans, molluscs or acorn barnacles and corals, the 

 two last being nibbled or broken off with a sudden wrench. 

 Such food once seized needs special mastication before 

 it can be digested, and to this end hard enamel, pavement- 

 like teeth are often present on the tongue and roof of the 

 mouth, or even in the throat. 



Remarkable is the dentition of the Wolf Blenny or Sea 

 Cat (Anarhichas), of our eastern and northern coasts, 

 a fish commonly sold under the name of " Rock Salmon." 

 It habitually eats the spine-covered Stone Crabs, Oysters 

 and giant Cockles, cracking the latter into pieces the size 

 of a half-crown and swallowing them whole. 



