GENERAL OBSERVATIONS- 81 



ranch, ten miles east of Toquerville, and also two miles west of Kanab. 

 They were obtained from the lower portion of the Shinarump Group, 

 the lowest group of Triassic strata in the Plateau Province. The specimens 

 are all very imperfect, but the following genera have been recognized : 

 Pcntacrimis, RJiynclionella, Camptonwtes, and Myalina. Besides these there 

 were fragments of other conchifers, the generic relations of which are not 



recognizable. The specimens of Pentacrinus consist only of joints of the 







column, like those of P. asteriscus Meek and Hayden, so common in the 

 Jurassic strata of the same region, and, indeed, seem undistinguishable from 

 those of that species. So far as can be determined, the fragments of liliyn- 

 chonclla may be those of the Jurassic, R. gnathopliora Meek, and those of 

 Camptonectes may belong to any one of the several species known to exiat 

 in the Jurassic strata of the Plateau Province. In short, if the collections 

 had been placed in my hands for determination, without any statement of 

 their stratigraphical position, I should have referred them to the Jurassic 

 period with no other doubts than those suggested by the imperfection of the 

 specimens. If their stratigraphical position is correctly reported, which I 

 know no reason to doubt, it seems certain that the strata containing them 



' C 



ought to be referred to the Jurassic rather than to the Triassic period. 

 Before such an important conclusion as this is reached, however, it will be 

 necessary to secure more perfect and complete collections. 



JURASSIC PERIOD. 



Twenty-seven species have been recognized among the Jurassic fossils 

 of the collections, at least four of which are new. With the exception of 



* 



two Echinoderms all the species are molluscan. 



Considerable interest attaches to the fact that a species of Unio has 

 been obtained from strata of this period at Flaming Gorge, Utah, indicating 

 the presence of fresh water at that point at one time during the period. 

 The fact is also of still further interest as indicating that the fresh-water 

 molluscan types which became so prevalent in the Tertiary period were 

 introduced early in Mesozoic time if not before. 



CRETACEOUS PERIOD. 



A much larger number of species, all of which arc molluscan, have 



been obtained from strata of the Cretaceous than from those of any one of 

 Or a 



