32 



FOSSIL FISHES. 



inflexible spines (Fig. 52, /.-), the otber rays of the fins being more 

 or less articulated and flexible ; the ventral fins are thoracic, and 

 the scales are usually ctenoid (Fig. 53, b). 



Pig. 52. — Skeleton of the Common Perch, a, Premaxillary bone; 6, maxillary bone; 

 c, lower jaw ; d, palatine arch ; e, cranium : /, interoperculum ; g <J ', vertebral column ; 

 h, pectoral fin ; i, ventral fin ; k, spinose dorsal fin ; /, soft dorsal fin ; 1,1, anal fin ; n, upper, 

 and n', lower lobe of caudal fin. 



[Theoretically the pair of pectoral fins are homologous with the anterior pair of limbs in 

 the higher Vertebrata, whilst the pair of ventral fins correspond to the posterior pair of 

 limbs. All the fins behind the ventral fins are merely accessory to the caudal fin, and, 

 properly speaking, belong to the tail. None of the other fins save the pectorals and ventrals 

 are paired.] 



The following families are represented by fossil genera and 

 species, namely : — 



The Percidce (to which family the well-known " Freshwater 

 Perch," Figs. 51 and 52, belongs) ; these fishes are abundant in some 

 of the Tertiary limestones, as in the Eocene of Monte Bolca, where 



species of Labrax, Lafes, Smerdis, Cyclo- 

 poma, Serramis, and many other genera 

 occur fossil. Paraperca has been met 

 with at Aix, and a large species of Perca 

 in the Miocene freshwater limestone of 

 (Eningen near Lake Coustance. 



The S^uamipinnes — " Coral Fishes" — 



FiSes/^^S^^B^Soidt a S rou P of fishes having the vertical fins 



(dorsal and anal) thickly covered with 

 scales, and comprising the beautifully-coloured fishes of the genera 

 Chatodon, Henioclms and Bolacanthus, chiefly inhabitants of the 

 Atlantic and Indo-Pacific areas. They have their fossil representa- 

 tives in the Tertiary of Monte Bolca near Verona, but they are 

 all referable to the existing genera, PomacantJms, Ephippium, 

 Scatopliac/us, and Kola cant Ji us. The genus Toxotes is also found 

 fossil at Monte Bolca. 



* Cycloid, circular scales. 



+ Ctenoid, having the margin toothed (comb-like). 



