94 



diletafa, G. cymUiim^ and G. calceolata of Europe, ^hicli have notliing 

 whatever in common with the Grijphoea Pitcheri or any other cretace- 

 ous species ; a clearer Paleontological case can seldom be seen ; but 

 Messrs. James Hall, W. P. Blake, and J. M. Meek have contrived to 

 make the matter difficult and dark, in the Reports on the Pacijic Rail- 

 road and the Mexican Boundary Commission. I have always con- 

 sidered their determination of fossils as valueless, and a few words of 

 explanation will show the degree of confidence that is to be placed in 

 them as accurate and reliable authorities. 



In vol. III. of the Pacijic Railroad Explorations, Mr. James Hall 

 has described and figured both fossils as varieties, the one of the 

 other. The descriptions and figures of Mr. Hall certainly do not 

 indicate a single species with varieties, but two distinct species, as 

 broadly distinct as two species of the same genus can be ; besides, he 

 refers all the specimens of Pyramid Mount to what he calls the 

 typical form of a small individual of Dr. Morton's Gryphcea Pitcheri, 

 while his G. Pitcheri, var. navia, are all from the False Washita, both 

 varieties not being found in the same locality, but at two hundred 

 miles distance from each other. This simple fact of stratigraphical 

 position and distribution is a strong objection to the identification of 

 the two fossils. Plate i, fig. 1-6, represents the Gryphcea Pitcheri of 

 Hall (not Morton or Roemer). Compared with the text the figures 

 do not give half the characters, and all the principal ones are want- 

 ing ; such as being " distinctly lobed," " beak strongly incurved," 

 " umbo large and prominent," " postero-ventral margin sinuate and 

 elevated in a fine corresponding to the depression in the opposite 

 valve," " impressed radiating lines near the centre ; " in fact, I do not 

 recognize a single one of the figures, drawn by Mr. Meek, as repre- 

 senting any specimens picked up by me at Pyramid Mount, and if 

 any of them came from there they are rolled and worn-out specimens, 

 probably picked up on the banks of Tucumcari Creek by some other 

 members of our expedition. Figures 7, 8, 9, and 10, on the same 

 plate, are intended to represent the Gryphcea Pitcheri, var. navia. 

 Mr. Hall says in the description, " upper valve unknown," when 

 figure 8 gives a complete specimen with upper and lower valves ; 

 figure 9, is also an upper valve of another specimen well preserved. 

 So the text is in complete disagreement with the figures. Further, 

 those figures 7, 8, 9, and 10, have been copied from my plate published 

 in May, 1855, in the Bulletin de la Soc. Gtol. de France, vol. xir. pi. 

 XXI., and the copy was so carelessly made by Messrs. Hall, Blake, 

 and Meek, that they have put the figure 10 as the side view of the 

 upper valve of figure 9, when in fact it is the side vicAv of the upper 

 valve of Gryphcea Tucumcarii, figured under the number 1 a and 1 h 

 on my plate, a specimen which has nothing to do whatever with the 

 False Washita specimens, even taking for granted the opinion of 



