458 R. T. Hill — The alleged Jurassic of Texas. 



1858. " This limestone is only five feet thick ; it is of a whitish- 

 gray color, containing an immense quantity of fossil Ostracea, 

 which I consider as identical with the Exogyra ( Gryphoea) pitcheri 

 Mort..-, having the closest analogy with Exogyra couloni, of the 

 Neocomian of the environ of Neufchatel (Switzerland). — Geology 

 of North America, Zurich, 1858, p. 17. 



This passage purports (Geology of North America, p. 7) to be 

 a " verbatim " copy of the preceding paragraph, and is copied 

 from the chapter in the latter work (p. 9) entitled u Extract from 

 Report of Explorations for a Railway Route, near the Thirty-fifth 

 Parallel oi Latitude from the Mississippi River to the Pacific 

 Ocean, etc., Washington, 1855, 11. Doc. 129." It should be noted 

 that he here, as in the preceding quotation, refers the genus to 

 Exogyra. 



1858. In the literal copy and translation of Professor Jules 

 Marcou's field notes by W. P. Blake, p. 131, vol. iii of the Pacific 

 Railway Reports, quarto edition of 1856, the Comet Creek local- 

 ity near Camp 31 is described as composed, of "three or four 

 broken beds with crinoids* disseminated here and there as if the 

 ruins were formed of a lumachelle limestone of Neocomian age. 

 This lumachelle is formed by the fragments of Oslrea aquila or 

 couloni or a variety, for it is smaller .... the four beds of 

 lumachelle are two feet." 



Concerning these notes, however, Mr. Marcou later said: "I 

 here declare that 1 know nothing of the publication of the edition 

 in quarto of these reports, and that I decline all responsibility as 

 to the use that may have been or may hereafter be made by 

 others of my official note books," etc. (Geology of North 

 America, etc., Zurich, 1858, p. 1.) Nevertheless he himself, now 

 (1897) cites them as authontative in his recent article, p. 205. 



1858. On page 27 of the Geology of North America, Mr. 

 Marcou says, in discussing his Neocomian in America, of which 

 this is the only locality recorded as seen by him, that "its thick- 

 ness varies from 6 to 50 feet." 



1862. " I have never seen Morton's original specimen 



I am led to believe that I did not meet witn the true G. pitcheri of 

 Morton in my explorations with Captain Whipple's party. Mr. 

 Ferdinand Roemer having the opportunity of seeing, in the com- 

 pany of the late Dr. Morton himself, the original specimen at Phila- 

 delphia, I naturally followed his identification of G. pitcheri; and 

 if Roemer has made a mistake I was misled by his description . . . 

 Thus we shall have three species of Gryphcea : 1, the G. tucum- 

 carrii of the Jurassic rocks of Pyramid Mount (New Mexico); 

 2, the false G. pitcheri of Roemer and Marcou, or the false G. 

 pitcheri var. navia of Conrad and Hall of the Cretaceous rocks of 

 the false Washita River (Texas) which may be called G. roemeri 

 in honor of its first discoverer, Mr. F. Roemer, and, 3, the true 

 G. pitcheri Morton, which I have never seen, and, consequently, 



* This word does not occur in the French version of the notes, in which Gr. 

 couloni is also followed by a question mark. 



