Mesozoic Series of New Mexico. — Marcou. 155 
"Little Blossom," "Arrow rock," etc., and on the Mississipj)!, 
"Bake Oven," "Grand Tower," etc. The lower Ohio, (probab- 
ly all of the river) the upper Mississippi (above the Ohio) and 
the lower Missouri are all of the same geological age. Begin- 
ning ab the close of the Palaeozoic or a little before, they were 
soon after developed into lively running streams. The Mis- 
souri wasY»robably a clear stream until joined willi the upper 
Missouri after the later Tertiary. 
University, Columbia, Mo-, Jul]/, 1889. 
THE M»SOZOIC SERIES OF NEW MEXICO. 
I. 
By Jl'LES >fARCOO. 
The June number of The A.merican Geologist contains a 
paper by Prof. J. J. Stevenson, "The Mesozoic rocks of south- 
ern Colorado and northern New Mexico," i)p. 391-397, based 
on such inexact principles that it confuses all the stratigraphy 
of four systems of rocks, the Carboniferous, the Trias, the 
Jura and the Cretaceous. At the end of his paper professor 
Stevenson makes use of language such that it is impossible 
even to quote it. However I shall answer him, in order to 
give a little more light, taking special care to stay only on the 
ground of geological facts observed in the field, and published 
in official reports, or in scientific periodicals. 
1853, Marcou. — New Mexico was geologically a complete 
terra incognita in 1853, when I reached it, after passing over 
another terra incognita from Little Rock, Arkansas, to the 
Llano Estacado, The Carboniferous system had been recog- 
nized in Iowa, Nebraska, Missouri and Arkansas, and its exis- 
tence had been signalized also on the San Saba river in Texas, 
and at Great Salt lake. The Cretaceous system was known 
to exist on the upper Missouri river, in Texas, and at Poblazon 
(New Mexico), without any attempt at any classification or 
synchronism with the Cretaceous of the eastern and southern 
states, and even less with Europe; except for the vicinity of 
New Braunfels in Texas, where Dr. F. Rammer had worked out 
the Cretaceous strata, giving a classification and synchronism, 
which on the whole has proved incorrect ("Texas." von Fer- 
dinand Rii'iner, p. 373, Bonn. 1849). After passing over Del- 
aware mountain or ridge (about 97° longitude and 3-1° 60' 
latitude in the Indian territory, Chikasaws nation), I entered 
