PLATE IX. 



Fig. Page. 



1. JJrinicliehj.^ nngJicus, A. S. AYoodward; head with opercular apparatus, 



rig-ht and left (1 a) lateral aspects, the type specimen. — A Turonian 

 zone; Houghton, Sussex. Willett Collection no. 100, Brighton 

 Museum, d., dentary ; eth., mesethmoid ; fy., frontal; hm., hyo- 

 mandibular ; iu,r., maxilla; op., operculum; j^"-^ parietal; |)rt,s'., 

 probably parasphenoid ; ^)?»,)'., premaxilla ; j>02)., preoperculum; qv., 

 quadrate; sp., sphenotic (postf rontal) . 31. 



2. Ditto ; hinder part of head, left lateral aspect. — English Chalk. Egerton 



Collection (B. M. no. P. 4510 a), a.s., alisphenoid ; sq., squamosal; 

 other letters as in fig. 1. 31. 



3. Ditto; remains of skull, quadrate (qn.), pterygoid arcade {'pf.), and 



mandible ((/.). — Prolial)ly a Turonian zone ; Dover. Daniels Collec- 

 tion (B. M. no. 36133). 31. 



4. Prionolepis angustus, Egerton; scales, chiefly shown from inner aspect, 



the type specimen. — Zone of Holaster suhr/lohofnis ; Burwell, 

 Cambridgeshire. Dixon Collection (B. M. no. P. 9253). v., vertical 

 ridge on inner face of scale. 43. 



5 — 8. Ditto ; four imperfect scales, outer aspect, twice nat. size, two 

 showing upper end, two showing lower end. — Zone of Hohi.^trr 

 planus ; Swaffham, Norfolk. C. B. Rose Collection (B. M. no. 29040). 

 /., course of lateral line. 43. 



9. Ditto ; scale traversed by lateral line (/.), outer aspect, twice nat. size. — 

 Zone of Holaster svhgJohosus ; Calne, Wiltshire. Cunnington Collec- 

 tion (B. M. no. 46393). 43. 



10. GimolicMlnjs lewesiensis, Leidy ; right palato-pterygoid arcade, inner 



aspect. — Probably a Turonian zone ; Burham, Kent. Egerton 

 ('ollection (B. M. no. P. 1810c). pi., posterior inner palatine tooth. 46. 



11. Ditto ; right palatine, oral face, showing two rows of, teeth. — Probal)ly a 



Turonian zone ; Burham. B. M. no. 36750. ?"., sockets for inner 

 row of teeth ; o., base of an outer tooth. 47. 



12. Ditto; right palatine, inner and upper (12^^) aspects. — English Chalk. 



B. M. no. P. 407. p., large posterior inner tooth. 47. 



13. Ditto; right mandibular dentition, outer aspect. — Zone of Holaster 



suhglohosns ; Hailing, Kent. Bowerbank (V)llection (B. M. no. 39122). 

 Three series of teeth numbered i, ii, iii. 48. 



14. Ditto ; left dentary, outer aspect. — Probably a Turonian zone ; Kent. 



Mrs. Smitli's (\)llocti()ii (B. M. no. 49066). 47. 



All the figures, except 5 to 9, of the natural size. 



