58 



1859. — J. W. Salter described ConocejyJialites antiqitatus from " a 

 cast in a brown sandstone, said to be a bouldered fragment from Georgia." 

 (Jour. Geo. Soc, vol. xv, p. 554.) 



1860. — Dr. B. F. Shumard announced the discovery of the Potsdam 

 sandstone and Calciferous sandrock or their equivalents in Burnet county, 

 in the State of Texas, and described one species, ( Orthis Coloi-adoensis,') 

 from the former. (Trans. Acad. Nat. Sci., St. Louis, vol. i, pp. 627, 

 672.) 



1860. — Sir W. E. Logan described and figured a track in the Pots- 

 dam sandstone under the name of Climactichnites Wihoni. This track 

 was discovered by Dr. James Wilson of Perth. (Can. Nat. GeoL, vol. 

 V, p. 279.) Dr. J. W. Dawson has described and figured the various 

 tracks of Limulus on the sand of the existing sea-beaches, showing very 

 clearly that both Protichnites and Climactichnites may be the tracks of 

 crustaceans. (Can. Nat. Geol. vol. vii, p. 273.) 



1860. — F. H. Bradley described Conocephalites minutus from the 

 Potsdam sandstone at Keeseville, N. Y. He also reported the occurrence 

 of the cast of a Pleurotomaria and a crinoidal joint in the same beds. 

 (Am. Jour. Sci. (2) xxx, p. 241.) 



1861. — Dr. B. F. Shumard described from the Potsdam of the locality 

 in Burnet county in Texas, above mentioned, Discina microscojjica, Cam- 

 erella (sp. ?), Cajndus (sp. ?) Agnostus Coloradoensis, Arionellus 

 (^Bathyurus) Texanus, A. (^Bathyurus) planus, Conocephalites depressus, 

 C. BilUngsii and BikelocejjJiahis, Roemeri. (Am. Jour. Sci. (2) xxxii, p. 

 213.) In this paper Dr. Shumard mentions the previous discovery, by Dr. 

 Ferd. Roemer, of trilobitcs in Texas which had been referred by Barrande 

 to the fauna of the Primordial zone. I have not access to Roemer's work 

 at present, or I would notice his species here. 



1862. — Dr. F. V. Hayden and F. B. Meek gave an account of their 

 discovery of the Potsdam sandstone around the Black Hills and other 

 localities along the eastern side of the Rocky Mountain range. They 

 described Oholella nana, Tlieca (^Pugiunculus) gregarea and Arionellus 

 Oweni from the Black Hills and Big Horn Mountains. They also cite 

 species either identical with or closely allied to Lingida prima and L. 

 acuminata, from the same localities. (Am. Jour. Sci. (2) xxxiii, p. 73, 

 Jan. 1862 ; alsoProc. Acad. Nat. Sci. Phila., Dec. 1861, p. 435). 



1862. — Dr. B. F. Shumard revised several of D. D. Owen's species, 

 and also described Dikelocephalus latifrone, Arionellus bifurcatus, and 

 Conocephalites minor from the Potsdam of Wisconsin. He also made the 

 first announcement of the occurrence of the genus Agnostus in this forma- 

 tion. The species noticed by him " appears to be identical with or at least 



