162 F. B. Meek on the Carboniferous Rocks of 
from Western Pennsylvania to the Rocky Mountains, and ftom 
Nebraska and New Mexico. Mr. Marcou figures it himself 
under the name Zerebratula subtilita, in his Geology of Norih 
America, even as a Mountain Limestone species, from Utah 
New Mexico. His so-called Zerebratula Mormonii, is a ia 
dedicated by him to the Latter Day Saints, from the fact that 
he first found it at their Capital City. It is worthy of note 
however, that he figures and describes it as a Mountain Lime 
stone species in the work just mentioned. So it would seem — 
this little shell, in migrating eastward, obtained a long leas 
of life, since it here turns up, according to the same authority, : 
in the so-called Dyas. The identity of the fossil is not questioned; — 
indeed the writer and Dr. Hayden long since identified he 
ranging through a great thickness of Coal-measures in Kai 
and northwestern Missouri. The notable point is, that it should — 
be in Utah a Mountain Limestone species, and here at Platte: — 
through all those yery Coal-measures in Kansas and Missou 
which Mr. Marcou refers to the Mountain Limestone. The g& 
logical position of Fusulina cylindrica, in this country has already i 
been explained. Productus longispinus, P. carbonaria and te 
D, 
Fr phiah Jasciger? by Dr. Owen, as explained in another place, 5 
i. ‘ 
was from the Plattesmouth locality. It is known to be ice : | 
where characteristic of the Coal-measures, from New Mexit0™ — 
Behrasion and from Western Pennsylvania’ to the Rocky Mout: : 
ains. ie 
The group of shells to which the name Monotis is often : 
plied in this country and England, and by some contin 
shi (though generically distinct from the Triassi¢ we 
y : d 
uppe 
nsas and Northwestern Missouri, ad by Mr. Ma 
i ES eaonitore: The names Avicula and ie a all 
oosely by paleontologists, that they may be said, as ge?” 
understood, to range ‘ita the Sieiee to “is existing seas 
Now, how any geologist, having even a limited knowledge 
American Carboniferous rocks and fossils, could regard #8 
* See Prof. Rogers’ Report Pa., ii, 838, fig. 694. 
