R. T. Rill — The alleged Jurassic of Texas. 459 



on which I cannot give any information as to its stratigraphical 

 position and association with other fossils. — Proc. Boston Soc. 

 Nat. Hist., vol. viii, p. 95, 1862." 



1889. "As to the Gryphcea pitcheri which Mr. Hall calls var 

 navia it is the true G. pitcheri of Morton and Roemer found by 

 me at Comet Creek near the false Washita river. — American Geolo- 

 gist, September, 1889, p. 163." 



1896. " The first strata of this Cretaceous system contain at 

 Comet Creek, Fort Washita, etc., an immense number of Gryphcea 

 roemeri Marcou (formerly called G. pitcheri by Roemer and 

 Marcou). The Gryphcea arcuata are so numerous as to recall the 

 ' Limestone of the Lias of "England, France, and Germany.' These 

 first beds, which may be called the 'Caprina and Gryphsea Roemeri 

 limestone; are the bottom beds of the American Neocomian or 

 Lower Cretaceous." — The Jura of Texas by Jules Marcou, Proc. 

 of the Boston Soc. Nat. Hist., vol. xxvii, p. 157, Boston, October, 

 1896. 



The foregoing extracts show that he has successively called 

 this Comet Creek species " Exogyra ponderosa Roemer," 

 " Exogyra pitcheri " with analogy with " Exogyra couloni " / 

 a Ostrea aguila or couloni f " " Gryphcea pitcheri" " Gryph- 

 wa roemeri" " Gryphcea pitcheri" and Gryphcea rcemeri." 



The paragraphs in Professor Marcou's paper to which I per- 

 sonally take exception are such as that on page 199, in which 

 he makes direct charges upon my veracity and the motives and 

 correctness of my work, citing " an example of carelessness, 

 not to use a stronger word, in quoting a plain paleontological 

 fact," which "shows how unreliable Mr. Hill is when he 

 writes on paleontology," and accusing me of endeavoring by 

 "extraordinary alteration" and misquotation of D'Orbigny to 

 make a certain species of Ammonite appear of Cretaceous 

 instead of Jurassic affinities. 



These accusations on Professor Marcou's part are absolutely 

 without foundation, as anyone can see by comparing my origi- 

 nal assertion with his extraordinary misrepresentation of it. 

 What I said was as follows :* 



Careful examination of the literature and specimens of the 

 Boston and Washington libraries and museums failed to reveal 

 any figured species with which this one can be identified. It 

 resembles generically the group Harpoceratidse (genus Ludwigia, 

 Boyle), which is peculiar to the upper Jurassic of Europe and 

 also Ammonites yo, If Orb, of the lower neocomian. The 

 absence of this ammonite from the great mass of the Trinity 

 strata, except in the place indicated, suggests that it may be an 

 older fossil reimbedded in the Trinity, but its preservation and 

 delicacy ol structure would seem to render this impossible. 



* Neozoic Geology of Arkansas, p. 128. 



