PLATE XXXI. 



Fig. Page. 



1. Protosphyraena ferox, Leidy ; rostrum, left side view, with inverted 



symphysial end of dentary beneath, one half nat. size; also (1 a, 1 b) 

 two transverse sections of rostrum showing extent of internal 

 cavity, one half nat. size. — Zone of Holaster subglobosus ; Blue Bell 

 Hill, Burham, Kent, S. J. Hawkins Collection (B. M. no. P. 6529). 

 d., dentary inverted ; v., vomer. 148. 



2. Ditto; right premaxilla, incomplete behind, outer and (2 a) lower 



views, two thirds nat. size. — Ibid. Mrs. Smith's Collection (B. M. 



no. 49012). 148. 



3. Ditto ; left premaxilla, incomplete anteriorly, outer view, two thirds 



nat, size.— Ibid. Harford Collection (B. M. no. P. 5634). 148. 



4. Ditto; right maxilla, inner view, with (4a) lower view of anterior end. 



— Ibid. Harford Collection (B. M. no. P. 5651 a). j>., antero- 

 internal process. 149. 



5. Ditto; portion of large left maxilla, outer view. — Zone of Holaster 



subglobosus ; Hailing, Kent, Wetherell Collection (B. M. no. 43092). 1 49. 



6. Ditto; left mandibular ramus, incomplete behind, outer and (6 a) upper 



views, one half nat. size. — Chalk ; Kent. Enniskillen Collection 



(B. M. no. P. 3955). <!., dentary ; spl, splenial. 149. 



7. Ditto ; lower front tooth, inner view, showing hollow (s.) for successional 



tooth at base. — Zone of Holaster subglobosus; Blue Bell Hill, 

 Burham. S. J. Hawkins Collection (B. M. no. P. 6530). 150. 



8. Ditto; transverse section of part of tooth, highly magnified, also (8a) 



outline of transverse section of tooth. 150. 



Unless otherwise stated, figures are of the natural size. 



