PALEONTOLOGY. 409 



is already identified with' the Athyris lamellosa of the Iowa locality. 

 Although there may be many entirely new forms embraced within the 

 vertical limits occupied by these same shells at the localities from which 

 they are derived, I do not think this is a sufficient reason why they 

 should be considered as other than equivalents of the Burlington and 

 Keokuk beds of the western States above mentioned. 1 



Plate XI is occupied principally by new forms from the Coal Meas- 

 ures, while Plate XII contains many previously described species. The 

 smaller forms represented being mostly illustrations of species found in 

 two separated layers of chert, within the limits of the Coal Measures, 

 near Webb Summit and at Mrs. Banks's Farm, Falls township, Hock- 

 ing county, which were particularly examined for determining their hori- 

 zons, and the figured specimens were obtained from them in place. These 

 species sufficiently mark their places as within the true coal bearing 

 series. 



For the interesting new forms illustrated on Plate XI, I am indebted 

 to H. Moores, Esqr., of Columbus, Ohio, and to Mr. Somers, of the same 

 place, who have taken pains to collect and send to me for examination 

 much of the well developed fauna of Carbon Hill, Hocking county, Ohio. 

 On this same plate is represented a new genus and species of air breath- 

 ing Mollusk, the discovery of which in the Coal Measures of Marietta, 

 Ohio, is an exceedingly interesting fact, as showing the wide distribution 

 over the American coal region during its formation, the conditions of 

 climate and terrestrial circumstances which permitted the existence of 

 this form of life to extend over Ohio, Indiana, and Nova Scotia. 



1 It may be well to state in this connection that these remarks were written in 

 1880.— R. P. W. 



