112 



FOSSIL FISHES OF THE ENGLISH CHALK. 



Family Elohm:. 



This primitive family of bony fishes is represented in existing seas only by two 

 genera, Flops (Text-figs. 34 — 37) and Megalops; but, as might be expected, it forms 

 a much more important feature in the fish fauna of the Cretaceous period. Of the 

 six genera from the English Chalk which appear to belong to it, only Osmeroides 

 is known by nearly complete specimens. The characteristic gular plate has not 

 yet been clearly observed in Pachyrhizodus, Elupopsis, Thrissopater, or Protelops. 



hm f 



pop wp q ecar snv 



1TWC 



Fig. 35. Elops saurus, Linn. ; head with opercular apparatus, right lateral aspect, cor., circumorbital 

 cheek-plates ; d., dentary; ecar., articulo-angular;/., frontal; hm., hyomandibular; iop., inter- 

 operculuni; mi., maxilla; n., nasal; ope, operculum; pm., premaxilla ; pop., preoperculum ; pt., 

 1 lost- temporal ; q., quadrate; sm., supramaxillse ; sop., suboperculum: si., supratenrporals. After 

 W. a. Ridewood. 



sop 



Pig. 36. Flops saurus, Linn.; left pterygopalatine arcade, mandible, suspensorium, and opercular 

 apparatus, inner aspect, br., branchiostegal rays; d., dentary; ecar., enar., articulo-angular; 

 •■rp., ect. .pterygoid; enp., en t o pterygoid ; hm., hyomandibular;' iop., interoperculum ; j., gular 

 plate; rrvpt., metapterygoid ; ope, operculum; /./'.. palatine; pop., preoperculum ; »., quadrille- 

 sop., suboperculum ; sy., symplectic. After W. G. Ridewood. 



