THE PHARYNGEAL TEETH OF FISHES. 455 



split along the centre line and opened sideways. To get an 

 accurate idea of the working position of these teeth the extreme 

 right and left edges must, in the mind's eye, be bent over toward 

 each other, and the edges made to touch ; this will then bring 

 the upper pharyngeals into their correct relative position to and 

 over the lower pharyngeal teeth. The food of this fish consists 

 of crustaceans, molluscs, echinoderms, and fish. 



Labrus turdus.* Fig. 2 (p. 454). 



The upper pharyngeal teeth are conical along the centre of 

 the patch, with more rounded ones at the sides. The teeth of 

 the lower pharyngeals have their summit more rounded than 

 the upper pharyngeal teeth. There is a promontory of teeth pro- 

 jecting forward in the mouth. In the illustration those at the 

 apex have unfortunately fallen out. The upper part of the 

 gullet has been divided similarly to and for the same reason as 

 explained for the last fish. 



Labrus festivus.* Fig. 3 (p. 454). 



The illustration is from a small specimen ; it has fourteen 

 short gill-rakers from the angle forward. They bear one or two 

 minute teeth on them. There are six gill-rakers along the first 

 epibranchial. The other arches have alternate gill-rakers, on 

 some of which are minute teeth. The upper pharyngeal teeth 

 are conical, the lower pharyngeal teeth at the back part of the 

 mouth are more rounded on the summit. Those at the apex of 

 the forward promontory are conical and sharp, especially the 

 most forward one of all, which also has a rake or leaning toward 

 the back part of the mouth. This would prevent a shellfish 

 being crushed by the molariform teeth from slipping forward 

 into the mouth again. 



Crenilabrus pavo. 

 The pharyngeal teeth are much the same as in the last one 

 described. In the specimen examined several of the teeth both 

 in the upper and lower pharyngeals showed signs of wear, as the 

 tops of them were gone, leaving an appearance of a small dark 

 ring, which was strongly suggestive of dental caries. 



" Both found in the Mediterranean, 



