I9I2.] STEVENSON— THE FORMATION OF COAL BEDS. 515 



well rounded, but those which are angular or subangular are quite as 

 abundant. Maclurea magna and a considerable number of other 

 forms are present in the limestone containing the pebbles. This local- 

 ity must have been very near a shore line ; there is no evidence to 

 suggest that the shore was precipitous and one must agree with 

 Butts that deposition in shallow water is indicated, although, accord- 

 ing to accepted doctrine, the fossils suggest deep water. The pres- 

 ence of fossils in the Chazyan limestones as well as in the Ames and 

 Vanport, wdiere the rock is changing into merely calcareous sand- 

 stone, makes clear that the presence of marine fossils is not to be 

 taken as final evidence of deposition in deep water. 



The Testimony of the Fossils. — There are few fossiliferous 

 liorizons in the Appalachian basin and collections have been made 

 at not many localities. But, if one bear in mind that the areas of 

 marine deposits are comparatively insignificant, the number of col- 

 lections will appear sufficient. 



A systematic collection of Mercer forms was made in the Zanes- 

 ville-Newark region of Ohio^°^ and some notes respecting the fauna 

 ■of the same horizon in Pennsylvania were given by I. C. White. 

 In the Ohio area there were obtained species as follows : One crinoid, 

 I coral, 5 bryozoans, 3 inarticulated brachiopods, 13 articulated 

 brachiopods, 40 pelecypods, 14 gastropods and 2 cephalopods. Ray- 

 mond^"'' has given a list of forms collected by him from the Vanport 

 at several localities in Beaver county of Pennsylvania ; it shows 3 

 corals, 2 bryozoans, one inar'ticulated brachiopod, 14 articulated 

 brachiopods, 3 pelecypods, 20 gastropods and 3 cephalopods. L C. 

 White added to this list from Lawrence county 2 crinoids, i articu- 

 lated brachiopod, 7 pelecypods, 5 gastropods and i cephalopod. 

 Twenty-three species are common to the Mercer and Vanport in 

 these lists. Probably the Vanport list is incomplete, as a consider- 



'°° Clara G. Mark, " The Mercer Limestone and its Associated Rocks in 

 the Zanesville-Newark Region," Bull. Set. Labor, of Denison Univ., Vol. 

 XVL, 191 1, pp. 267-314; L C. White, Sec. Geol. Surv. Penn., Rep. Q, p. 68; 

 Rep. Q2, p. 61. 



'""P. E. Raymond, "A Preliminary List of the Fauna of the Allegheny 

 and Conemaugh Series in Western Pennsylvania,"' Topog. and Geol. Surv. 

 {of Penn.], 1911, pp. 83, 84. 



