BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA 



Vol. 10, pp. 397-408, PUS. 45-48 DECEMBER 26, 1899 



JURASSIC FISHES FROM BLACK HILLS OF SOUTH 



DAKOTA* 



BY C. R. EASTMAN 



(^Accepted for "publication by the Society May, 1899) 

 CONTENTS 



Page 



Scarcity of fossil fishes in American Jura-Trias and Jura 397 



Description of the more perfect fossils 398 



Comparison of family characters ... 399 



Method of preparing illustrations used 401 



Details of body parts . 402 



Head , 402 



Fins 403 



Scales 403 



Details of figured specimens 404 



Relations to other species 405 



Description of fragmentary fossils 406 



Amiopsis (f) darioni sp. nov , 406 



Fin fragments. 407 



Explanation of plates 408 



Scarcity of fossil Fishes in American Jura- Trias and Jura 



As contrasted with other countries, the American Jura-Trias contains 

 an extraordinarily meager representation of fossil fishes. The supposed 

 Triassic sandstones of the eastern United States yield in all hut six 

 genera and a limited number of species, the majority of which are im- 

 perfectly preserved. In none of these has the osteology of the head 

 been satisfactorily worked out, and our knowledge of skeletal details still 

 leaves much to be desired. The existence of piscine life in the western 

 Trias is indicated by sparsel}'' scattered fragments, nothing more. 



An even greater dearth of this class of vertebrates prevails in the Amer- 

 ican Jura, standing in marked contrast to its wealth of reptilian and 

 mammalian remains. A few small Dipnoan teeth, described as Cera- 



*This paper was not preseated before the Society either by reading or by title, but was ac- 

 cepted by the Publication Committee as a desirable and important adjunct to Mr Darton's paper 

 which precedes it. 



LVII— Bur.T,. Geoi,. Soc. Am., Vol. 10, 1898 (397) 



