578 
PLATE LVI. 
Page 
Fics, 1-7. Psammopus rucosus, Agass., . 6 : ; 459 
Fie. 1. Upper surface of a large example of the commonest form of the teeth. 
, la. Lateral view of the base of same specimen. 
», 10. Anterior extremity of the same, showing thickness of base and crown. 
Fies. 2, 3, 5. Examples of ordinary form of the teeth. The upturned left lateral extremity 
of figure 2, may be noted. The hollow has probably been produced by the 
grinding of the opposing teeth. The hump of figure 5, is also peculiar. 
Fias. 4, 6. Triangular teeth occupying the positions indicated in the woodcut on page 462, 
at the anterior extremity of the palate. 
Mountain Limestone, Armagh, : Ex coil. Bristol Museum. 
Fic. 7. Triangular tooth, similar to those above. 
Mountain Limestone, Armagh, Le coll. Enniskillen Collection. 
