ANACANTHINI. 



173 



Family. — Gadil\e. 



The type-family of this order is that which includes the 

 cod-fish, haddock, and other species of the Linnaean Gaclns. 

 The Merlinus cristatus and Rhinocephalus planiceps of the 

 London clay, are the oldest known forms of the family; the 

 true cod-fish (ftlorrhua), is not known to have existed before 

 the present (human) period. 



Family. — Pleuronectidjs. 

 (Fiat-Fishes.) 



In this family the symmetrical form is lost, and both eyes 

 are on one side of the head. Species of still existing genera 

 of this much-modified family have been found in tertiary 

 deposits. The little turbot (Rhomhios minimus, e.g., fig. 81) 



Fig. 81. 

 Mhombus minimus (Monte Bolca). 



occurs in the tertiary deposits of Monte Bolca. An equally 

 extinct species of sole (Solea antiqua) has been found in ter- 

 tiary marls near Ulm. 



Order VI.— MALACOPTEEL 



Char. — Endo-skeleton ossified ; exo-skeleton as cycloid scales ; 

 fins supported by rays, all of which, save the first in 



