194 



Fig. 51 represents what I suppose to bo a fragment of a maxillary of the 

 same fish. It is provided with teeth as in Amia, Salmo, and some other 

 genera. 



Associated with the specimens of the character above described there are 

 a number of others, consisting of small fragments of bones with close patches 

 of short conical teeth, like the vomerine and other similar patches of teeth of 

 Amia. 



The dentary fragment of Fig. 49 contains the remains of a dozen teeth in 

 the space of 11 lines. The specimen of Fig. 50 contained thirteen teeth within 

 ■a space of 10 lines from the symphysis. Of the retained teeth the last is the 

 longest, and measures nearly 3 lines. The others are about 2\ lines in length. 

 The premaxillary fragment of Fig. 48 contained seven teeth in a space of as 

 many lines. The first tooth is the longest, and measures 2f lines. In 

 the other fragment of Fig. 47, ten teeth occupied a space of 8£ lines. 



The genus supposed to be indicated by the specimens has been named from 

 the light-house-like form of the teeth. 



REMAINS OF FISHES FROM THE SHALES OF GREEN RIVER, WYOMING. 



In Professor Hay den's Preliminary Report on the Geology of Wyoming 

 for 1870, p. 142, the author remarks that soon after leaving Rock Springs 

 Station, on the Union Pacific Railroad, the Green River group is seen on the 

 bluff hills on either side of the road to the entrance of Bitter Creek into 

 Green River. In the valley of the latter remarkable sections of strata 

 are exposed to view. The group he calls the Green River shales, because the 

 strata are composed of thin layers, varying in thickness from that of a knife-blade 

 to several inches. The rocks all have a grayish-buff color on exposure, some- 

 times with bands of dark brown. These darker bands are saturated with a 

 bituminous matter which renders them combustible. 



About two miles west of Rock Springs Station there is an excavation on 

 the railroad which has been called the. Petrified Fish Cut, on account of the 

 thousands of beautiful and perfect fossil-fishes which are found on the surface 

 of the thin shales, sometimes a dozen or more on an area of a square foot. 

 Remains of insects and aquatic plants are also found in the shales, and in one 

 instance a well-preserved portion of a feather of a bird was discovered. 



A large collection of fossil-fishes from the Petrified Fish Cut, obtained by 

 Professor Hayden in lb70, was submitted to Professor Cope, who has described 

 the different forms in the report above mentioned. 



