stanton.] NORTHERN UTAH. 41 



of calcareous deposits which may be represented elsewhere by a much 

 greater thickness of shales and sandstones. Provisionally I have taken 

 the base of the conglomerate No. 5 as the top of the Colorado forma- 

 tion at this locality. The soft strata of No. are seldom exposed in 

 the Coalville area and no fossils have been found in them, but they 

 appear to belong with No. 7. 



The overlying 1,800 feet of shales and sandstones are fossiliferous at 

 several horizons, but their strict paleontologic correlation with Creta- 

 ceous formations of other regions is difficult for several reasons. In 

 the first place several of the most abundant and best preserved species 

 are not known to occur in well defined formations elsewhere. Others 

 again belong to types that are known to have a great vertical distribu- 

 tion and many are not sufficiently well preserved to admit of positive 

 specific determination. And finally, after allowance has been made for 

 all these defects, the evidence seems to be conflicting. Strati graphi- 

 cally it is evident that these beds hold the position of the Montana 

 formation, but whether they should all be referred to that formation or 

 part of them should be regarded as the time equivalent of the Laramie 

 must still be left an open question. It is a question that may have an 

 important bearing on the more general problem of the condition of the 

 continent during the Laramie epoch. A very promising field for the 

 study of this question is in western Wyoming along the uplift of "Oys : 

 ter ridge" and west of it, where at least a part of these upper beds and 

 the horizon of the Evanston coal are both represented in the same 

 neighborhood. 



Before giving the lists of fossils from these upper beds I will state 

 that there is no doubt concerning their relative positions. The sand- 

 stones of No. 8, dipping 20° to 25°, form a nearly vertical escarpment 

 beneath which the softer beds of No. 7 are exposed in a steep bare 

 slope showing in some places almost every layer. The lower 25 feet 

 of No. 7 exposed beneath the coal bed yielded : 



O.strca coalvillensis. Corbnla subtrigonalis? 



Anomia propatoris. Cardium. 



Modiola Hiultilinigeraf Barbatia. 



The clay shales immediately associated with the coal seams contain 

 large numbers of fossils in which fresh water, brackish water, and 

 marine forms are commingled. The following list includes those 

 recorded by Prof. Meek from the old Carleton coal mine, nearly all of 

 which have been collected by myself at another exposure on the oppo- 

 site side of the Weber river, and about 3 miles distant: 



Modiola multilinigera? Neritina baimisteri. 



Anomia propatoris. Eulimella? chrysallis. 



Cyrena carletoni. Eulimella? inconspicua. 



Unio. Melampus antiquus. 



Turritella spiroiicma. Valvata nana. 



Neritina bellatula. Pbysa carletoni. 

 Neritina carditoides. 



