THE TEETH OF FISHES 93 



sometimes attains an enormous size, with a snout 

 six feet long and twelve inches wide (see Fig. 13). 

 The Teleostei, or true bony fishes, possess teeth 

 which are ankylosed to the various bones of the 

 head; some are hinged, and but rarely are they 

 implanted in sockets. They consist usually of 

 vaso-dentin with an irregular covering of enamel. 

 The teeth are very numerous, and are scattered 

 irregularly over most of the bones and cartilages 

 of the mouth and head, even to the gills and oc- 

 cipital bones. In numbers they often run into 

 thousands, as in the Pike where the mouth is 

 covered with sharply-pointed conical teeth sloping 

 backward to hold struggling prey. Some of these 

 teeth are large on the sides of the mouth, and may 

 be hinged, and arranged in rows or in groups. 

 The marginal teeth are usually ankylosed, but the 

 palatal teeth are often hinged. The bands or 

 groups are all directed backward to assist swallow- 

 ing. The usual shape is that of a simple cone, but 

 this is varied greatly, and may be fine and small, 

 or large and long and recurved as in the Pike, 

 Cod, and related forms. Or again they may be 

 rounded and blunt as in the Wolf -fish ; or so small 

 as to be mere denticles on the jaws ; in the Gymno- 

 donts the teeth and jaws are fused into one mass 

 like a beak; hinged teeth are found in the Hake, 

 Pike, Cod, Angle-fish, etc., which assist in hold- 

 ing struggling prey; the Sargus has teeth of 



