104 



Fig. 51 represents what 1 suppose to be a fragment of a maxillary ol' 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 thei-e 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 hnes. The others are about 2J 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 8J lines. 



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

 the light-house-like form of the teeth. 



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



In Professor Hayden'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 remarkal)le 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 dai-ker 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 und 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 I)y 

 Professor Ilaydcn in 1;)70, was subinilted to Professor Cope, who has described 

 tiie different forms in tlir i('[»orl al)ove mentioned. 



