1809.] ^' [Winchcll. 



with a degree of paleontological acuteness which cannot be gainsayed, that 

 both the Rockford beds, and the three members of the Chemung group 

 of Missouri as interpreted by Professor Swallow, present characteristics 

 which forbid their introduction into the Devonian system. They affirm 

 the judgment of de Verneuil, that the Black Slate of the West is the 

 equivalent of the Genesee Shale of New York. In an appended note they 

 propose to adopt the name Kinderhook group for the rocks in Illinois 

 lying between the Black Shale and the Mountain Limestone. 



Some time in 1862, Professor HalP^ published a " supplementary note" 

 to his paper on the Rockford limestone, in which he states that having 

 identified the Rockford Goniatites Eyas among fossils from the Waverly 

 sandstone of Licking cou.nty, Ohio,^^ he is led to "conclude that the 

 position assigned to the Goniatite beds of Rockford may be erroneous, and 

 that the true position is higher in the series, or more nearly in a parallel 

 with the Chemung group." 



During the year 1862 large additions were made to our exact knowledge 

 of the species of fossils embraced in the series of rocks immediately under- 

 lying the Mountain Limestone. In February, Messrs. White and WhitfiekF^ 

 published a paper entitled "Observations upon the rocks of the Missis- 

 sippi valley, which have been referred to the Chemung group of New York, 

 together with descriptions of new species of fossils from the same horizon 

 at Burlington, Iowa." This paper embraces descriptions of 31 new species. 

 The authors in their introductory remarks, synchronize the yellow sand- 

 stones of Burlington, with the Chemung of New York, though admitting 

 the strong paleontological contrast, and their striking affinity with the 

 Burlington limestone and higher carboniferous rocks. This opinion is 

 founded tipon the identification of several Iowa and Missouri fossils with 

 species from the Waverly series of Ohio, which is assumed to be in physi- 

 cal contimiity with the Chemung of Western New York, as originally 

 alleged by Professor Hall. 



In April, Mr. White™ published further descriptions of new species 

 from the same horizon at Burlington, Iowa ; Hamburg, Illinois ; and 

 Hannibal and Clarkesville, Mo. ; and in the same month Professor Swallow^' 

 published descriptions of two new species from the Chouteau, limestone of 

 Missouri. 



In May I published^^ ^ paper "On the rocks lying between the Carbon- 

 iferous Limestone of the Lower Peninsula of Michigan, and the limestones 

 of the Hamilton Group, with descriptions of some Cephalopods, supposed 

 to be new to science." Of the species enumerated, 24 were from the 

 Marshall group, and one from the Huron. In this paper the Black Shale 



■ ^^ Fifteenth Report New York Regents, App., p. 81. 



58 Having mj'self examined the fossils, I do not consider it identified with G. Ixion, Meek and 

 Worthen (=It. Hyas, Hall.) but with G. Marshallensis, Winchell, which differs from G. Lyoni by 

 constant technical characters, having an additional accessory lobe and saddle, and having the dorsal 

 lobe broader and relatively longer- A t.ransverse section of G- Lyoni, is broadest near tlie umbilicus, 

 while a section of G. Marshallensi? is regularly oval- Professor Hall's inference, however, remains 

 unchallenged. 



59 Proc- Boston Soc Nat. Hist- vol. viii, p. 2S9- ™ Proc- Boston Soc Nat. Hist-, vol- ix, p- 8. 

 •51 Trans- St. Louis Acad- Soi-, vol- 2, p- SI- ^^ Amer Jour Sci, [2,J xxxiil., 352. 



