EXPLANATION OF THE PLATES AND WOODCUTS. 



PLATES VIL, VIIL and IX. 



Illustrate Mr. Owen's memoir on Zeuglodon cetoides : p. 69 to 79' 



Plate VIL 



A fragment of the upper jaw of the Zeuglodon cetoides, showing three of the complex two- 

 fanged molars in situ, and part of the alveolus of a fourth : the form and depth of im- 

 plantation of the fang is shown at the fractured surface, at the opposite extremity of the 

 fragment. 



Plate VIIL 



Fig. 1. A transverse horizontal section of the middle of the crown of one of the double-fanged 

 molars of the Zeuglodon. 



Fig. 2. A similar section through both fangs of the same molar, taken two inches below the 

 preceding. 



Fig. 3. A similar section of the crown of the posterior molar of the Dugong. 



Fig. 4. Ditto, ditto, of an anterior molar of the Manatee. 



Fig. 5. A transverse section of one of the ribs of the Zeuglodon, showing the form of its prin- 

 cipal component layers. 



Fig. 6. A caudal vertebra of the Zeuglodon, on the scale of six inches to a foot. 



Plate IX. 

 Two views of the humerus of the Zeuglodon, on the scale of six inches to a foot. 



PLATES X., XL, XII. and XIII. 



Illustrate Mr. Owen's paper on Glyptodon clavipes : p. 81 to 106. 



Plate X. 



Generic characters of the Glyptodon : 

 Fig. 1 . Side-view of a molar tooth : p. 86. 

 Fig. 2. Grinding surface of ditto (both of the natural size). 



Fig. .S. Outside view of the left hind-foot, wanting the small external and internal toes (two- 

 thirds natural size). 



as. Astragalus : p. 90. 



c. Calcaneum : p. 91. 



sc. Scaphoides : p. 92. 



en. External cuneiform bone : p. 92. 



