ANACANTHINI 



149 



Family. — Pleukonectid^e. 

 {Flat- 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 (Rhombusminimus, e.g., fig. 63) 

 occurs in the tertiary deposits of Monte Bolca. An equally 

 extinct species of sole (Solea antique^ has been found in ter- 

 tiary marls near Ulm. 



Fig 63. 



HhoDtbus minimus (Monte Bolca). 



Fossil fishes of the cod, mullet, carp, salmon, and herring 

 genera, are found in the tertiary formations, but are distinct 

 from all known species. The Ganoids in these formations are 

 reduced to the genera Lcpidostcus and Acipensci* ; but may 

 have been represented by the palates with crushing teeth, 

 from the Sheppy clay, to which the names Pisoclus and 

 Pliyllodiis^ have been given. 



With respect to the fishes of the tertiary period, " they 

 are so nearly related," says Agassiz, " to existing forms, that 

 it is often difficult, considering the enormous number (above 



* See Owen's Odontography, p. 138, pi. 47, fig. 3. 

 f Ibid, p. 139, pi. 47, figs. 1 and 2. 



