No. 442.] FOSSIL FISHES OF MOUNT 



other three species of the genus are from Sahel Alma. Three 

 of the species from Yankton belong to Leptosomus. Two 

 other species of Leptosomus are known from Westphalia and 

 two from Mount Lebanon. Cope supposed that these fishes 

 were obtained in the Niobrara deposits; but, judging from their 

 close relationships with Mount Lebanon forms, it appears highly 

 probable that they came from a higher horizon, probably the 

 Pierre. It is a matter of considerable importance that some 

 geologist in that region should explore these beds. There 

 appear to be great numbers of the fishes, since on one block 



one on the opposite side. The reader will find a figure of this 

 block on Plate 5, of volume 19 of the Bulletin of the American 

 Muse um of Natural History. 



