stanton.] NORTHERN UTAH. 43 



Laramie, though it does occur associated with marine forms in the upper- 

 most Fox hills beds. The Admetopsis is apparently the same species 

 that occurs so abundantly with Ostrea soleniscus, Modiola multilinigerafj 

 etc. 7 near the base of the upper division of the Upper Kanab section. 

 The species of Neritina belong to types that range from the Colorado 

 to the Laramie. In fact none of the brackish-water species of these 

 lists would be thought out of place if they were found in the Laramie. 

 But when it is known that the beds containing them are overlain by 

 ] ,800 feet of marine Cretaceous strata their Laramie age is rendered 

 very doubtful. In many respects the facts observed recall the Belly 

 Biver series of the Canadian geologists, but at Coalville tlie brackish- 

 water conditions seem to have been too limited both in area and dura- 

 tion to be regarded as more than a temporary phase — perhaps an estu- 

 ary — in a marine formation. 



Twenty feet above the bed from which the plants were obtained and 

 in the same exposure a thin layer of sandstone is filled with the remains 

 of marine invertebrates mostly in the form of casts. The following 

 species have been collected from it : 



Cardium cur turn. Gyrodes. 



Cardium n. sp. fc Pyropsis. 



Mactra arenaria. Fusus 



Mactra formosa! Baculites ovatus? 



Tellina isonemat Placenticeras placenta var. 



Donax cuneata? intercalare. 



Barbatia. Scapliites. 



Anatina. 



The most abundant and best preserved species are Cardium curtim 

 and Mactra arenaria, neither of which has been found elsewhere than 

 in this immediate region or in the strictly equivalent strata of west- 

 ern Wyoming. Of the others the bivalves and the gasteropods are of 

 doubtful value, and the cephalopods apparently belong to the fauna of 

 the Montana formation, though the Placenticeras also occurs in the 

 Colorado formation. 



The more massive sandstones of No. 8 have yielded — 



Ostrea soleniscus. Cardium. 



Ostrea sannionis. Donax? 



Tellina subalata? Baculites ovatus. 



Mactra formosa? Placenticeras placenta, var. 



Mactra arenaria. intercalare. 



Pkoladomya subventricosa. 



It has already been shown that marine Cretaceous fossils have been 

 found at two other horizons above this, one near the middle of No. 9 

 and the other in No. 10, and they all belong to the fauna represented 

 in the last two lists. 



After attempting to give due weight to each element in this Conflict- 

 ing evidence it seems to me most reasonable to refer the strata contain- 

 ing the "Laramie" plants and the brackish-water invertebrates of 



