370 



ANATOMY OF VERTEBRATES. 



2-19 



jaws and teeth 



250 



between the villiform and radulifonn types. Setiform teeth 

 are common in the Fishes thence called Chaetodonts ; ! in the 



genus Citharina they bifurcate at 

 their free extremities ; in the genus 

 Platax they end there in three di- 

 verging points, and the cone here 

 merges into the long and slender 

 cylinder, fig. 253. 



Sometimes the cone is compressed 

 into a trenchant blade : and this may 

 be pointed and recurved, as in the 

 Murcena ; or barbed, as in Trichiurus, 

 and some other Scomberoids ; or it 

 may be bent upon itself, like a tenterhook, as in the fishes thence 

 called Goniodonts. 2 In the Bonito may be perceived a progressive 



thickening of the base of 

 the conical teeth : and this 

 being combined in other 

 predatory fishes with in- 

 creased size and recurved 

 direction, they then resem- 

 ble the laniary or canine 

 teeth of carnivorous quad- 

 rupeds, as we see in the 

 large teeth of the Pike, in 

 the Lophius, fig. 260, and 

 in certain sharks, fig. 263. 

 The anterior diverging 

 grappling teeth of the wolf- 

 fish form stronger cones ; 



and by progressive blunting, flattening, and expansion of the 



apex, observable in different fishes, the 

 cone gradually changes to the thick and 

 short cylinder, such as is seen in the back 

 teeth of the wolf-fish, and in similar grind- 

 ing and crushing teeth in other genera, 

 whether feeders on sea-weeds or on crusta- 

 ceous and testaceous animals. The grind- 

 ing surface of these short cylindrical teeth 

 may be convex, as in the Sheep's-head 

 fish (Sart/us)', or flattened, as in the 

 pharyngeal teeth of the Wrasse (Labrus, fig. 254). Sometimes 

 the hemispheric teeth are so numerous, and spread over so broad a 



Teeth of Tench, v. 



251 



Teeth of Lepidosiren. xxxm. 



, a bristle ; uSovs, n tooth. 



ia, an angle ; oSouy, a tooth. 



