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Notes on Pal.eozoic Crustace.k, No. 1. 



On so7ne new Scdnlia Trilohites. 



By A. W. VoGDEs. 



The large and extensive family of trilobites, which consisted 

 of eighty-one genera in the American Palaeozoic age, is only rep- 

 resented in the Carboniferous by seven families. Of these the 

 genera Proetus^ Cyphaspis^ Dalmanites{ ?) and Phcvthonides 

 are Devonian fossils, w^hich reappear in the Lower Carbonifer- 

 ous limestones. The genera Phillipsia^ Grijffithides and Bra- 

 chymctop2is are typical fossils of the Carboniferous. These 

 genera range as follows : Phillipsia from the Waverly series up 

 into the Permian, Griffithides extends from the Keokuk to the 

 Coal Measures. The last genus is very rare, but a persistent 

 genus of the Lower Carboniferous appearing in the English, 

 Irish, Russian, Australian and American groups. In England, 

 Russia and Australia only one species appears. The Irish 

 carboniferous rocks contain four species, and the American the 

 following species : Brachymetopus Lodiensis^ Meek, B. znima- 

 fi(rus, Herrick, from the Waverly of Ohio. From Sedalia we 

 have the new species described in this paper, making in all only 

 eight species. 



The fossil Crustacea of the Sedalia limestones have a strong- 

 Devonian facies, being represented by the genera Proetus and 

 Cyphaspis ; in fact such was the classification given by Swal- 

 low to the Chouteau group, Missouri Geol. Rep. 1S55, p. loi ; 

 and to the Chemung by Prof. James Hall, Geol. Iowa, 1858, p. 

 103. They were referred to the Kinderhook by Worthen, Geol. 

 Illinois, vol. i, p. 109, in 1866. Since these investigations, Mr. 

 F. A. Sampson of Sedalia has described in the Trans. N.Y.Acad. 

 Sci. vol. 7, 18S8, p. 247, the pygidium of a Proetus with 9 axial 

 rings and 7 pleurae, the axis being marked with 3 rows of nodes ; 

 his collection also contained a glabella which unquestionably be- 

 longs to the genus Cyphaspis. Dr. White also called attention 



