Isospondyli 



57 



Other species are Phareodus acutus, known from the jaws; 

 P. cncaustus is known from a mass of thick scales with retic- 

 ulate or mosaic-like surface, much as in Osteoglossum, and 

 P. cequipennis from a small example, perhaps immature. 



FIG. 45. Phareodus testis (Cope). From a specimen 20 inches long collected at 

 Fossil, Wyo., in the Museum of the Univ. of Wyoming. (Photograph by 

 Prof. Wilbur C Knight.) 



Phareodus testis is frequently found well preserved in the shales 

 at Fossil Station, to the northwestward of Green River. 

 Whether all these species possess the peculiar structure of the 

 scales, and whether all belong to one genus, is uncertain. 



In Eocene shales of England occurs Brychatus muelleri, a 

 species closely related to Phareodus, but the scales smaller and 

 without the characteristic reticulate or mosaic structure seen 

 in Phareodus encaustus. 



The Pantodontidae. The bony casque of Osteoglossum is 

 found again in the Pantodontidce, consisting of one species, 

 Pantodon buchholzi, a small fish of the brooks of West Africa. 



