58 



1859. — J. W. Salter descrilicd Oonocejjhaliti's antiquatus from " a 

 cast in a brown sandstone, said to l>e a bouldered fragment from Georgia." 

 (Jour. Geo. Soc, vol. xv, p. 5:j4.) 



I860. — De. B. F. Siiumard announced the discovery of the Potsdam 

 sandstone and Caleiferdus sandroclc or tlioir equivalents in Burnet county, 

 in the State of Texas, and described one species, (OrtJiis OoIoraJocnsis,') 

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

 672.) 



I860. — Sir W. E. Logan described and figured a track in the Pots- 

 dam sandstone under the name of Olimarftrlnntcs Wihoui. This track 

 was discovered by Dr. James Wilson of Pei-th. (Can. Nat. Geol., vol. 

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

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

 clearly that both Proticlmiti's and (JUmiirtlchniicii may be the tracks of 

 crustaceans. (Can. Nat. Geol. vol. vii, p. 27o.) 



1860. — F. H. Bradley described Cunuccj-Jialitcs mhuttns from the 

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

 of the cast of a J^Jcurotainaria and a crinoidal joint in the same bods. 

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



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

 in Burnet county in Texas, aliove mentioned, Dixcina i.ueroscvjyica^ C'am- 

 erella (sp. ?), Cajniluv (sp. ?) Af/nox(i(s Coloradoeiixis, ArioncUus 

 (^Bathyunis) Tc.vanus, A. { Bathi/nri's') jihtnus, ConocepJinJ/'tcf! i.li'pn'xsus, 

 C. Billiiujsii and Dlkehjccphuhix^ Jloenwrt. (Am. Jour. Sci. (2.) xxxii, p. 

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

 Ferd. Roomer, of trilobites in Texas which had been referred by Barrande 

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

 at present, or I would mitice his sjiecies 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 JMcaintain range. They 

 described Ohulella na7ia, Theca (^Pugiunculus) [ircijan'a and Ariondlus 

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

 species either identical with or closely alUed to Linr/ida prima and L. 

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

 Jan. 1802 ; alsoProc. Acad. Nat. Sci. Phila., Dec. 1861, p. 435). 



1802. — Dr. B. F. Shumard revised several of D. D. Owen's species, 

 and also described JJikclocepiludna latifrone, Arionellus hifurcatus, and 

 Conuccphditcs minor from the Potsdam of AVisconsin. 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 



