lOO BULI^ETIN 12 238 



The presence of Goniatites oweyii, together with nine other 

 Rockford fossils, in the Marshall group of Michigan, which 

 Winch ell^^ has reported, indicates that the Rockford is represented 

 in Winchell's Marshall group and that the Rockford limestone 

 is the stratigraphic equivalent of some part of the Marshall group, 

 but certainly not of all of it.f 



The tables showing the range of the faunas in the Indiana and 

 Kentuck}^ se(5lions indicate clearly that the fauna of the Rockford' 

 limestone is the earliest of the Carboniferous faunas in these sec- 

 tions. It may be designated faunally after the name of one of 

 its most characfteristic species as the Miuisteroceras oweni zone of 

 the Eocarboniferous. 



Riverside Sandstone and New Providence Shale Faunas. 



The relation between the faunas of these two formations has 

 been found to be of the closest kind. Neither of the formations 

 is generally fossiliferous. In the lower especially fossiliferous lo- 

 calities are scarce, but when found the fossils are apt to be abund- 

 ant. In both formations the faunas seem to have lived in colo- 

 nies covering quite limited areas, with considerable stretches of 

 uninhabited or at least very sparsely populated sea bottom be- 

 tween. 



The sandstone in northern Indiana designated as the Riverside 

 sandstone by Mr. HopkinsJ has been correlated with the upper 

 sandstone and sandshale of the Knob region in southern Indiana 

 on the evidence of fossils collecfted at and near the typical local- 

 ity. The following species were obtained: 



Lingulodiscina newberryi, Rhipidomella sp. , Spirifer sp. , Spir- 

 ifer keokuk, Spirifer striatiformis, Spirophyton crassuvi, Syringo- 

 thyris texta, worm trails. 



This is a charadleristic fauna of the upper "Knobstone" of 

 southern Indiana. Syringothyris texta and Spirifer keokuk are 

 found at nearly all fossiliferous localities in these beds. Spirifer 

 keokuk has never been found by the writer in the New Providence 



*Pr. Am. Phil. Soc, vol. 12, p. 396. 



t " " " " " " " 397- 

 j2oth Ann. Rept. Ind. Dept. Geol., p. 287. 



