PLATE XLT. 



Fig. Page. 



1. Eddpliodoii maiitelli (Buckland) ; left mandibular dental plate, inner and 



(1 a) upper views, two-thirds nat. size. — Tiu'onian zone ; Lewes, 

 Sussex. B. M. no. P. 5405. a., beak with tritor ; c, d., anterior 

 and posterior outer tritors ; c, median tritor. 186. 



2. Edapliodon afjasshi (Buckland) ; left mandibular dental plate, outer, 



inner (2 (/), and upper {1h) views, nat. size. — Zone of HolaHter 

 sidxjlohosns ; Southeram, near Lewes. Capron Collection (B. M. 

 no. 49723). Letters as in fig. L 187. 



3. Edaphodon sp. ; distal portion of dorsal fin-spine, side view, nat. size. — 



Zone of Holaster subglobosns ; Blue Bell Hill, Burhani. S. J. Haw- 

 kins Collection (B. M. no. P. G525). 188. 



4. Edaphodon sp. ; hinder view of portion of dorsal fin-spine showing double 



series of denticles, nat. size, with (4rt) some of the denticles in 

 side view enlarged three times. — Zone of Holaster siilxjluhusus ; 

 Burham, Kent. B. M. no. 43390. 188. 



5. Isclii/odiLs {?) incisns, Newton ; left mandibular dental plate, outer, inner 



(5(r), and upper (5 h) views, nat. size, with (5 c) broken section of 

 beak enlarged twice to show tritors. The type specimen. — Chalk ; 

 Kent. Toulmin Smith Collection (B. M. no. 41083). 190. 



0. Ditto ; left mandibular dental plate, outer view, nat. size. — Zone of 



Holaster suhylohosns ; Burham. B. M. no. 47942. 190. 



7. Ditto ; left vomerine dental plate found Avith the preceding specimen, 



outer and (7 ft) inner views, nat. size. B. M. no. 47943. 190. 



8. Gaiorhijiiclhus crrtaccas, Dixon; imperfect spine, nat. size, with (8 f?) 



portion of ornament enlarged three times. The type specimen. — 

 Zone of Holaster snjjfjlohosns ; Sussex. Enniskillen Collection 

 (B. M. no. P. 3942). 193. 



9. Ditto ; transverse section of spine, four times nat. size, with (9 a) part 



of the same more highly magnified. — Senonian zone; Norwich. 

 Bayfield Collection (B. M. no. 48956 ft), 193. 



