PLATE VIII. 



Fig. Page. 



1. Hojjlopteri/x simiis, sp. nov. ; head from anterior and (1 a) left lateral 



aspects.— Chalk ; Kent. Harford Collection (B. M. no. P. 5700). 

 ao., antorbital ; co., circumorbital ring ; eth., mesethmoid ; fr., frontal ; 

 mx., maxilla; pmx., premaxilla; s., scales on cheek; smx. 2, pos- 

 terior supramaxilla ; socc, snpraoccipital, viewed from above ; ii, iir, 

 paired slime-cavities. 23. 



2. Ditto ; hinder part of cranium with upper part of opercular apparatus, 



lower part restored in outline. — Chalk ; Kent. Mrs. Smith's Collec- 

 tion (B. M. no. 49074). iop., interoperculum ; ojj., operculum; jxip., 

 preoperculum ; v., ridge bounding hollow on cranial roof originally 

 occupied by muscles ; sop., suboperculum. 23. 



3. Ditto ; right mandibular ramus, inferior aspect, showing bridges of bone 



over large slime-canal. — Chalk; Kent. Mrs. Smith's Collection 

 (B. M. no. 49073). Dotted line indicates long axis of head. 24. 



4. Ditto; some scales of flank, showing course of lateral line (/.). — 



English Chalk. B. M. no. P. 387. 24. 



5. Trachichthyoides ornatus, gen. et sp. nov. ; head with opercular apparatus, 



from left lateral and upper (5 a) aspects. — Chalk ; Bromley, Kent. 

 Bowerbank Collection (B. M. no. 39076). cL, clavicle; d., dentary ; 

 pa., parietal ; pet., pectoral fin ; pfo., pterotic region ; other letters 

 as in figs. 1, 2. 29. 



6. Homonotus dorsalis, Dixon ; head with opercular apparatus, right lateral 



aspect. — Zone of Holaster subglohosus ; Burham, Kent. B. M. no. 

 41673. ao., antorbital; d., dentary; qn., quadrate; other letters as 

 in figs. 1, 2. 25. 



7. Ditto; imperfect fish, left lateral aspect. — Zone of Micraster coraiigti.l- 



num ; Bromley, Kent. B. M. no. 43264. a., anal fin; ao., part of 

 antorbital; c, caudal fin; d., dorsal fin-spines, partly restored from 

 counterpart; ,/'/•., frontal region; ]>lv., pelvic fins. 25. 



All the fisrures of the natural size. 



