128 NEW YORK STATE MUSEUM 



These lists bring out the following facts: (i) that a considerable num- 

 ber of characteristic Guelph fossils appear as early as the Racine beds, a 

 few even in the Lower Coral beds, (2) that the large brachiopods 

 (Trimerellids) appear before or with the earliest Guelph gastropods (as at 

 Shelby), (3) that neither the Racine nor the Guelph beds of Wisconsin 

 contain a pure Guelph fauna, but also numerous Niagaran forms. 



Hall and Clarke, 1 writing at a later date than the work cited, give the 

 following brachiopods from Wisconsin : 



Rhinobolusdavidsoni H. & C, Grafton, Monomerella cf. 

 orbicularis Billings, near Grafton, M. egani H. & C, Grafton, M. 

 greeni H. & C, Grafton, Dinobolus conradi Hall, Racine, Graf- 

 ton. Schuchert cites 1 also C o n ch i d i u m occ i d e n tal e Hall, Williams- 

 town, Stricklandinia mul til i rata Whitfield, Sheboygan. 



Iowa. Dr Samuel Calvin in the Report of the Geological Survey of 

 Iowa, 1896, 5:50, has divided the Niagaran into four stages from the top 

 down : Bertram, Anamosa, Le Claire, Delaware (Hall's Niagara). 



In regard to the Le Claire stage it is stated that its strata are restricted 

 to the southwestern corner of the Niagaran area. It is generally a massive 

 or heavy bedded, highly crystalline dolomite. It contains little chert and 

 in its lower part there are few fossils. There are occasionally specimens of 

 Pentamerus of the P. occidentalis type, and casts of corals. In the 

 upper part small brachiopods abound of the genera Homoeospira, Tremato- 

 spira, Nucleospira, Rhynchonella, Rhynchotreta, Atrypa, Spirifer and prob- 

 ably others. 



The Le Claire limestone is, in some respects, unique among the geologic 

 formations of Iowa. Locally, it varies extremely in thickness, so that its 

 upper surface is very undulating and it is strongly cross bedded. It is 

 suggested by Calvin that the eddies of strong currents piled up the material 

 in lenticular heaps. 



Anamosa stage. This is Hall's " Onondaga salt group ", an earthy, 



1 Pal. N. Y. 1892. v. 8, pt 1. 



2 Synopsis Am. Paleoz. Brach. 1897. p. 187. 



