EXPLANATION OF THE PLATES AND WOODCUTS. 



PLATES XLIIL to XLVIL 



Illustrate Mr. Owen's paper on parts of the skeleton and teeth of five species of Labyrintho- 

 don: p. 515. 



Plate XLIIL 



Fig. 1. Portion of the upper jaw of Labyrinthodon leptognathus, seen from above: p. 516-521. i 



Fiy. 2. The same, seen from below: p. 517-521. ! 



a, Large anterior tusk of the outer dental series : p. 517. ; 



b, Left vomerine bone, supporting the inner series of teeth: p, 519. 



c, Posterior palatal foramen : p. 520. I 



d, Part of anterior dental foramen : p. 520, 521. 1 

 Fig. 3. Side view^ of the same fossil: p. 516-521. 



a, Large anterior tusk of the outer dental series. 



b, Ditto ditto inner or vomerine series. \ 



c, Bony palate forming the floor of the nasal cavity. * 



d, Roof of nasal cavity. i 



e, The nasal cavity, filled with matrix. i 

 Fig. 4. Fovtion o£ left u^'per ^aw of Labyrinthodon pachygnathits : p. 528. ' 

 Fig. 5. A smaller fragment of the same. 



Fig. 6. Serial teeth of the Labyrinthodon pachygnathus. \ 



Figs. 7« and 8. Two views of a portion of the lower jaw of Labyrinthodon pachygnathus. ■ 



Fig. 9. Vortion of the uTpjier ^aw of Labyrinthodon pachygnathus : p. 529-530. ] 



c. Origin of the outer plate of the intermaxillary bone : p. 530. I 



b, Outer palatal plate of the same bone : p. 530. ' 



c, Inner palatal plate, forming the anterior palatal foramen. i 

 Fig. 10. Side-view of the same fossil: p. 529-530. i 



c, Anterior palatal foramen. ' 



d, Maxillary or upper wall of nasal cavity. i 



e, Nasal cavity, filled with matrix : p. 530. 

 Fig. 11. Anterior frontal : p. 530. 



The thickness of the anterior and posterior margins are shown in the appended figures. 

 -F?^. 12. Portion of an undetermined bone of XG^ynra^Aoc?ow. 



Fig. 13. An undetermined bone of Labyrinthodon. \ 



I 

 1 



Plate XLIV. - [ 



Fig. 1. Portion of the right ramus of the lower jaw of the Labyrinthodon pachygnathus : p. 526. 

 Fig. 2. Inside view of anterior end of the same fossil : p. 526. 



a, Anterior and external suture between the angular and dentary pieces. 



b, Canal of the angular piece, supporting the dentary: p. 526. ] 



c, c, Dentary piece. I 



d, Anterior prolongation of the angular piece. , 

 Fig. 3. Upper view of ditto: p. 526. I 



