PLATE XII. 



Fig. Page. 



1. Cimolirliihys lewesiensis, Leidy ; head witli opercular apparatus, upper 



aspect and (1 a) left lateral aspect. — English Chalk. Egerton 

 Collection (B. M. no. P. 1811). ag., articulo-angular ; d., dentary; 

 /;•., frontal ; mx., maxilla ; lui., nasal ; oj)., operculum ; ^ja., parietal ; 

 pmx., premaxilla; jjop., preoperculum ; ptt., post-temporal; scl., 

 sclerotic; .S5n,i\, supramaxilla ; socc, supraoccipital ; sop., subopercu- ■ 

 lum. 45. 



2. Ditto; head, broken across rostrum, right lateral aspect. — A Turonian 



zone; Leaves. Enniskillen Collection (B. M. no. P. 5491). cr., 

 backwardly crushed crest of hyomandibular (hm.) ; mpt., meta- 

 pterygoid ; qu., quadrate; other letters as in fig. 1. 45. 



2 a. Left ceratohyal of same, inner aspect. 48. 



3. Ditto ; barbed upper tooth, with part of crenulated hinder border en- 



larged (3 ft). — Zone of Holaster suhglobosus ; Westwell, Charing, 

 Kent. Harris Collection (B. M. no. P. 329). 46. 



4. Ditto; barbed upper tooth.— Chalk; Burham, Kent. B. M. no. 40143. 46. 



5. Ditto ? {PUnthophorus robitstus, Griintlier) ; slightly distorted trunk, 



right lateral aspect, one half nat. size, with a ventral scute (5 a) en- 

 larged twice. — Zone of Holaster suhglobosus ; Folkestone. B. M. no. 

 38113. a., anal fin; c, caudal fin ; do., dorsal fin; pcf., pectoral fin ; 

 ph., pelvic fin-support ; x., scute enlarged in fig. ha; i, ii, iii, rows 

 of scutes. 48. 



All the figures, except 3 a, 5, 5 a, of the natural size. 



