96 



On looking more closely at the plates of the Mexican Boundary 

 Report, I found on the last plate, No. xxi., figure 3 a, 3 6, 3 c, a 

 specimen of Gryphma Tucumcaril under the false name of Gryphcea 

 Pitcheri. Mr. Conrad, in his description of Gryplioea Pitcheri, p. 155, 

 makes no reference whatever to that plate, nor to the figures 3 a, 3 &, 

 3 c; and in the Explanation of Plates of Prof Hall's Report, p. 174, 

 nothing is said of the locality or the stratigraphical position of this 

 fossil. The plate was drawn by Mr. F. B. Meek, who has put it 

 under the head of Cretaceous. The mysterious appearance of this 

 beautiful fossil is rendered still more suspicious from the fact that, at 

 p. 144, reference is made to plate xxi., in order to bring in the sup- 

 posed Gryjohma Pitcheri, figured upon it, as a prOof of the cretaceous 

 age of the formation ; and Mr. Agassiz is made (in a foot-note) to 

 sustain this opinion, although it is well known that he has considered 

 these two fossils as distinct, from the beginning. 



For any reader not deeply interested in the matter, that page 144 

 of the Description of Cretaceous and Tertiary fossils by Conrad, will 

 seem to be written by Conrad himself; when in fact ]Vii\ Conrad had 

 nothing to do with it, and in order to find the writer we must look at 

 the foot of page 103 of Geology and Paleontology, by Mr. J. Hall, where, 

 in a foot-note, he says that he has described the " Echinodermata 

 at the request of Mr. Conrad, putting them in their proper place," 

 without saying if it is also at the request of Mr. Conrad that, in de- 

 scribing his Echinodermata, he figured in plate xxi. a Gryphoea 

 Tucumcarii under the false name of G. Pitcheri. Desirous to know 

 the opinion of Mr. Conrad himself on these incomprehensible and 

 doubtful proceedings, I wrote to him, and give below his answer : — 



Philadelphia, January 25, 1861. 

 Jules Marcou, Esq.: 



Dear Sir : — When I drew up the Report in Emory's Survey, I was 



shown by Professor Hall a series of Gryjjhcea, some of which were undoubtedly 

 your G. Tucumcarii, as figured on plate xxi. Pi-ofessor Hall thought they 

 graduated into G. Pitcheri, and I thought so at the time. The name of your 

 species ought not to have been placed as a sjmonym to plate vii., figure 3, for 

 it is undoubtedly G. Pitcheri. 



But the figures on plate xxi. represents a species and specimen, the locality 

 of which is unknown to me, and were engraved after I had sent in my report 

 and descriptions. So that I can now say, that I do not know whether G. 

 Pitcheri is identical with your species or not. 



The localities of the G. Pitcheri (page 155, Leon Spring, Texas; plains of 

 Kiamesha, Arkansas; New Braunfels, Texas; Fort Washita and Cross Tim- 

 bers, Texas), are correctly given, from MSS. accompanying the specimens. 

 sincerely yours, T. A. Conkad. 



That the G. Tucumcarii is found at Leon Spring, is a fact first 

 made known in my Report of 1854, from a specimen picked up there 

 by Dr. Kennerly, and it is also certain that cretaceous fossils have 



