PLATE XX. 



Fig. Page. 



1. Sj/llsenms anglious (Dixon) ; head and abdominal region, the type specimen, 

 left lateral aspect, nat. size. — Probably from zone of Holaster planus ; 

 Burham, Kent. Egerton Collection (B. M. no. P. 611). ag., articulo- 

 angular; ch., impression of ceratohyal ; d., dentary; do., dorsal fin ; 

 11. , lateral line; mx., incomplete maxilla; op., operculum; pet., 

 pectoral fin; plv., pelvic fin; pop., preoperculum ; scl., ossified 

 sclerotic; smx., portion of snpramaxilla ; sop., suboperculum. 89. 



2: Ditto; imperfect fish, right lateral aspect, three-quarters nat. size. — 

 Chalk; Shalford, near Guildford. Capron Collection (B. M. no. 

 49737). c, caudal fin; cl., clavicle; orb., orbit; x., scale with, 

 radiating marks of slime-canal ; other letters as in fig. 1 . 

 2 a. Portion of two caudal fin-rays, nat. size, to show articulations. 89. 



