-I ati: QE0L0GIS1 ill 



ifty -five speci iminated in the foregoing list, 



■ ■nl\ sixteen ha nbtfully identified with species 



hitherto described. Of these sixteen, twelre only arc known 

 to the wril cur in the carboniferous rocks of tto w - 



e distributed as folio* 

 In • I Measures: Produdu* Wit"- 

 In:, iskia Limestone: Product AthyrU 



\ (?) Alio- 



In the St. Louis Pro- 



A • K I stella, 



• 

 In the >■(;<■!' ■ 



'mix. 



!n i state ol <wv i. .it v ould be pn ina- 



pt to identify the Carboniferous Limestone of 



►ring 

 ,; ion maj d to the following 



1 

 1. > d in tlio 



I 'Ted. 



thai at ! :' our formation lie ; 



•1. 'i ion of i .. ith forms from I 



with that part 

 nf the system. The bit er of many j 



the rock, if anywhere, to the same relationship. 



I he ferruj u the 



rmation, may easily mark the boundary lii 

 the twe ive epochs Last mentioned; although, at 



it, it is impossible to say whether the distribution of the 

 ith such a separation. 



