DESCRIPTION OF THE PLATES. 
Fig. 4. Part of a jaw of some ruminant in the calcareous mass of the Gibraltar rock. 
5. A fossil elephant's tooth, with plates in an undulating form. 
6. A fossil elephant’s tooth, remarkable for the thickness of its plates. 
7- A fossil elephant’s tooth, remarkable for the disposition of its plates. 
8. A fossil elephant’s tooth, in which twenty plates exist in the length of six inches and 
a half. 
9. A fragment of a fossil tusk, showing its structure. 
PLATE XXI. 
Fig. 1. A fossil molar tooth of the hippopotamus of the right side of the lower jaw, and which 
has not long pierced the gums. 
2. A fossil upper molar tooth of the rhinoceros. 
3. A fossil tooth of the tapir. 
4. The outer surface of the fourth molar tooth of the lower jaw of Palceotherium medium. 
5. The inner surface. | 
6. The outer surface of one of the molares of the upper jaw. 
7. The inner surface. 
8. The antepenultimate lower grinder of the Anoplotherium. 
9. The grinder which stands before the one Fig. 8. 
10. The fossil claw-bone of the Megalonix ; half the natural size. 
] 1. A fossil tooth of the Megalonix. 
PLATE XXII. 
Fig. 1. Skeleton of theMegatherium. 
2. The hindmost grinder of the upper jaw of the fossil bear of the caverns. 
3 The middle upper grinder. 
4. The foremost upper grinder. 
5. The hindmost grinder of the lower jaw. 
6. The penultimate grinder of the lower jaw. 
7. The antepenultimate lower grinder. 
8. The foremost lower grinder. 
9. The canine tooth of the fossil bear. 
