202 rAL.EONTOLOGY. 



isolated spot, would appear to be a matter of some importance in a strati- 

 grapliical j)oint of ^•ie^v. The genus Froetus seldom occurs in rocks above 

 the Devonian, but is here represented by two distinct species; one of which, 

 P. 2>c>'occidcns, has been recognized at three different localities. Besides 

 the species illustrated on the plate, there are represented, in the collection, 

 from near Dry Canon, a species of Syrw(jo}}ora, and a small-celled, closely- 

 aggregated Cyatliophylliim, an undetermined Productits, and a Platyceras; 

 also what appears to be a Goniatite, but too imperfect for determination. 



Above the limestone beds bearing Waverly fossils, at Dry Canon, and 

 separated from it by about twelve hundred feet of limestone, occurs a band 

 of somewhat sandy calcareous shale, filled with Bryozoans, among which 

 can be recognized a Fenesiella, a Poly2Jora, and a Glauconome, together with a 

 species of Spirtfcra too indistinct for determination; above this sandy 

 shale there is nearly or quite another thousand feet of limestone, near the 

 top of which occur the fossils figured on plate V. These latter are all of 

 Lower Carboniferous forms, and mostly of known species, and interesting, 

 as occurring in limestones without any intermingling of Coal-Measure types, 

 a feature rarely met with in the Carboniferous localities of the Far West. 

 The species represented are known in the more eastern localities as charac- 

 teristic of several of the Lower Carboniferous divisions; but none of them 

 occur in the true Coal-Measures, except Productus semireiicidatus, which is a 

 well-known cosmopolitan. 



The age of the shales containing the Bryozoans is somewhat doubtful, 

 as there are no known species by which to identify them Avith other local- 

 ities ; but the layers holding the fossils in question, and which occur just 

 beneath the Weber quartzite, would appear to represent nearly all the 

 divisions of the Lower Carboniferous as recognized in the Mississippi Valley. 

 At one time, it was hoped, by Mr. Clarence King and his associates, that 

 the Weber quartzite might prove a line of separation between the Lower 

 Carboniferous and the true Coal-Measures; but all the localities except this 

 one have yielded fossils of both formations, or of Coal-Measure forms only, 

 showing a mingling of the two fauna^, as usually recognized in the Missis- 

 sippi Valley and eastward, but in this locality, only the lower forms occur. 



