Isospondyli 283 
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. @quipennis from a small example, perhaps immature. 
Fic. 216—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 Brychetus muelleri, a 
species closely related to Phareodus, but the scales smaller and 
without the characteristic reticulate or mosaic structure seen 
in Phareodus encaustus. 
The Pantodontide.—The bony casque of Osteoglossum is 
found again in the Pantodontide, consisting of one species, 
Pantodon buchholzi, a small fish of the brooks of West Africa. 
