THE EXTINCT SAURDONTS 



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There is no air bladder, and very small eggs are produced by the ductless ovaiies. 

 This fish, which attains a length of two feet, has been obtained in Japanese waters 

 at a depth of between three and four hundred fathoms. 



Z.ONG-FINNED HERRING. 

 (One-fourth natural size.) 



THE EXTINCT SAURODONTS Families ENCHGDONTID^E, 



SAUROCEPHALIDsB, etc. 



Before proceeding to the consideration of the herrings, we may briefly refer 

 to a group of more or less closely-allied extinct families, mainly characteristic of 

 the Cretaceous period, but also represented in the lower Tertiaries. From the 

 large size of their 

 lanciform, reptile- 

 like teeth, all the 

 members of the 

 group are collec- 

 tively spoken of as 

 the saurodont fishes. 



The first family 



{Dercetidce} is typified by the genus Dercetis, of the Chalk, and is characterized by 

 the elongated form of the body, the large size of the teeth, which are implanted in 

 sockets, and the presence of several rows of large triangular bony plates along the 

 sides of the body; the muzzle being frequently produced into a beak, and the dorsal 

 fin single. Nearly allied is the family (Enchodontida:} represented by the widely- 

 spread Cretaceous genera Enchodus and Eurypholis; these fishes having the body 

 moderately compressed, and, either naked or partially protected by bony plates, 

 and the elongated upper jawbones armed (like those of the lower jaw) with small, 

 immovably welded teeth. To a third family belongs the genus Saurocephalus , 

 from the North American Cretaceous, which, together with the allied forms, has 

 the body much compressed, the large upper jaw armed with powerful teeth, usually 



SKELETON OF A SAURODONT FISH (Eurypholis). 



