97 



also been found there by Col. Emory ; but it is not necessary to place 

 the G. Tucumcaril in the same bed with the cretaceous fossils, for the 

 Jurassic and cretaceous rocks may well exist together in that locality. 

 I have always believed that the cretaceous strata would be found 

 overlying the Jurassic rocks on the plateau between Rio Pecos and 

 the Rio Grande, on the road to El Paso, and I have no doubt 

 that a practical geologist will one day give a detailed section, showing 

 such an arrangement of the strata in the vicinity of Leon Spring. 



I have taken pains to have a very good plate of the G. Tucumcani, 

 G. Pitcheri, and 0. JMarshil, drawn in Paris by the best artist there 

 for fossils, M. Humbert ; that plate is not only in the Bulletin de la 

 Soc. Ge'ol. de France, vol. xii., but also in my Geology of North 

 America, with descriptions of the three species. I have placed speci- 

 mens in a good state of preservation in the following collections : 

 Museum des Naturalistes de Moscow ; Museum at Berlin by Hmn- 

 boldt himself and Mr. Mulhausen ; at the Museum of the Universities 

 of Munich, Basle ; at the Royal Museum at Stuttgart ; at the Ecole 

 Polytechnique of Zurich ; at Pictct's collection at Geneva ; D'Ar- 

 chiac's collection ; at the Jardin des Plantes, and the Ecole des 

 Mnes, at Paris ; at the Geological Society of London (where are the 

 specimens figured on the plate) ; and finally, at the Museum of Com- 

 parative Zoology at Cambridge, Mass. So it will be always easy to see 

 what I mean by G. Tucumcarii and G. Pitcheri, notwithstanding the 

 Hall, Blake, and Meek imbroglio. 



In conclusion, if Dr. B. Shumard continues to hold the opinion that 

 he finds my G. Tucumcarii and OMrea Marshii at Fort Washita, with 

 cretaceous fossils, I hope he will be induced to give a good drawing 

 of them, with detailed descriptions, and a real section of the strata at 

 Fort Washita, like my detailed section of Pyramid Mount, in order 

 to allow geologists to judge for themselves avec connaissance de cause ; 

 but as long as he contents himself with simple affirmation, and 

 theoretical sections, his views will have no more weight than a mere 

 contradiction of mine, without proofs to sustain them. 



Mr. Marcou remarked that in a recently published letter of Sir Wm. 

 E. Logan to M. Barrande, the former admits a primordial fauna in 

 Canada. In a list of one hundred and thirty-seven species of fossils 

 in the beds near Quebec, not one was found common to them and 

 the Anticosti group, where there is a gradual passage from the fauna 

 of the Hudson River formation to that of the CHnton, and not one of 

 any formation higher than the Chazy. The Quebec group is in long 

 and narrow synclinal forms, separated on the main anticlinals by dark 

 gray and even black shales and limestones, which he had formerly 

 considered as belonging to the Hudson River group ; now that he 

 finds them separating the synclinals of the Quebec group, he must 



PROCEEDINGS B. S. IJ. H.— VOL. VIII. 7 MAY, 1801. 



