TELEOST-LIKE GANOIDS 



I6 5 



group is known to have attained its prominence at a later 

 geological time than the other Ganoids ; it is doubtless 

 derived, more or less directly, from the main ganoidean 

 stem. Three of the more typical Mesozoic forms are 

 shown in Figs. 169, 170, 171, in Cat urns, Leptolepis, and 



Fig. 170. Leptolepis sprattiformis. X f. (From SMITH WOODWARD.) Lith- 

 ographic stone, Solenhofen. 



Megalurns. To these amioid forms the ancestry of the 

 (majority of the) Teleosts is reasonably to be traced. 



A general scheme of the phylogeny of the Teleostomes 

 is suggested on the adjoining page (Fig. 171 A). 



B. Teleocephali (Teleosts.) This group, popularly known 

 as that of the bony fishes, or Teleosts, includes as great 

 a proportion perhaps as 95 per cent of the kinds of fishes 



Fig. 171. Megahirus elegantissimus, Wagner. 

 Solenhofen. 



X |. (After ZITTEL.) Jura, 



living at the present time. The immense number of their 

 genera and species is doubtless suggestive of the form 

 changes which occurred during the flowering periods of 

 the sharks, chimasroids, or lung-fishes. 



Teleosts have diverged most widely of all fishes from 



