SiO 



GEOLOGY OP EASTERN WISCONSIN. 



FOSSILS OF THE MAYVILLE BEDS OF THE NIAGARA GROUP. 



Genera and Species. 



pa 



W 



a 



PETKOSPONGIA. 



Stromatopora conoentrica 



CORALS. 



Favosites Niagarensis 



F. favosus 



Astrocerium veniistum 



Halysites oatenulaatus 



HeUolites pyrif ormis 



Diphyphyllum CEespitosum . 



Zaphreutis, und. sp 



Cyathophyllum, und. sp . . . 

 Ghonophyllum Niagarense . 

 Araplexus, und. sp 



BItACHIOPODA. 



Orthis flabellula 



0. res. 0. hybrida 



Strophodonta striata 



Strophomena rliomboidalis 



Meristina, res. M. cyKndrica 



Eetzia aprinis^Rhynohospira aprinis 



Atrypa, n. sp 



Pentamerus f omicatus 



P. oblongus 



Gypidula, res. G. oooideutalis,H. but smaller . 



Stncklandinia, und. sp 



LeptocceKa planooonvexa 



GASTEROPODA. 



Euomphalus Raoinensis. 

 Bucama, und. sp 



CEPHALOPODA. 



Ormoceras, prob. 0. vertebratura. . . 



CRUSTACEA. 



lUffinus, res. I. Barriensis 



Economic Value. From the analyses already given, it will be 

 seen that some portions of this formation are remarkably pure dolo- 

 mites, while others are notably impure. From the description already 



