STATE GEOLOGIST 87 



should yield to hie judgment But the shells in question leem 

 |q Ml - to Olymenia, and 1 can do nothing- but 



i,l them as Bucb until I am convicted or positively con- 

 tradict 



mot doubt that the palaeontologies! characi atrat- 



phical position of the Marshall sandstone place it conclu- 

 the horizon of the Hamilton Group; and hence I 

 am not surprised that none of the nine 



xibed by Prof. Hall, and referred by him to the Hamilton 

 Group, hear any considerable resemblance to the Michigan 

 - under consideration. 

 From this group were collected, at Battle Creek, the speci- 

 „„.., ed byR. P. Stev< I Leda dcn^mammillafa, 



l, ivctd&formis, L. pandonrformi?, Nucida Houghioni and 

 \fichigancm v e of the Lamellibranchs has 



ly identified by me, amongst the fossils collect- 

 locality. The Xuculoid shells have not the 

 lia] iinua terior elongation required by their assign- 



ment to the _ ■da; nor, supposing them true NtiCulw, do 



1 find their specific characters clearly indicated. M reover, Dr. 



. i,. ■< ochreous shales, belong- 

 1 with an Ortho- 

 which is evidently carl 

 eda an oversight Th< 

 blishes their Devonian 

 • \phon supposed to be the one refei 1 1 

 quit* /.'. Urei of Fleming, which is a dorsally a 



ttO trace of such a character. Still 



further, /;. Urei, even if occurring here, would not identify 

 these rosks with the "coal :, .'" ainoe tho range of this 



the Upper Silurian t<> the Mountain Lim< at 

 Tip- genera] aspect of the fauna of the Marshall Group bears 



i d by t ; i the 



fossil remains of the Rhenish Provinces of N Qer- 



XXV. [2] p. 262. 

 ■fSee huidb<rger'B Systematic: bung und, Abblldung der WrsUinorungen do* 



RLciuJ-chcu Schlchttaey ittma in Nassau. 



