224 The Mesozoic Series of New Mexico. — Marcoii. 
of the mesa opposite old Pecos church. Professor Stevenson 
has extended there the Carboniferous, on the whole area of the 
Rio Pecos valley, in places which to my knowledge are occu- 
pied only by the Triassic system. 
Professor Stevenson divides his Dakota group into upper, 
middle and lower, with a thickness of no less than 1,700 feet, 
admitting an abnormal increase of thickness, and a lithology 
very variable and differing from the Dakota of the state of 
Colorado. He does not give the name of a single fossil, and 
passes silently over the finding there by Dr. Newberry of 
dicotyledonous leaves and of Gryphcea j^itcheri. He calls it 
a "Dakota groujj greatly expanded," "but while so doing made 
the remark tliat the whole series maij he Triassic, or may he 
Cretaceous, the grouping having been made simply for con- 
venience ;'' an uncommon way of classifying Mesozoic rocks. 
And professor Stevenson adds : "This remark is too narrow, 
as it left the Jurassic out of consideration . . . there is a 
possibility that some portion of this may helong to the 
Jurassic. But the writer is inclined rather to look upon it 
all as belonging to the Cretaceous.'''' (The American Geologist, 
vol. III. p. 396, Minneapolis, June, 1889.) 
These quotations and remarks show what sort of confidence 
can be given to professor Stevenson's geological map of New 
Mexico, and to his classification and description of the New 
Mexican Mesozoic rocks. 
Classification of New Mexican and Texan Mesozoic 
SERIES. As a resume the following Table V, (p. 225) expresses 
the views entertained from the beginning of the classification of 
the various formations, by their different authors. They are 
placed in order of dates. 
I shall add that Dr. Newberry said at the Berlin meeting 
of the International Congress of Geologists : "Je suis fonde 
a dire que quant au Permien proprement-dit, il n'exist par 
dans les Etats Unis." Mr. James Hall joins Dr. Newberry in 
his view of suppressing the Dyassic system in America ( Con- 
gres Geologiqrie, 3me session, 1885, p. c. Berlin, 1888). Pro- 
fessor Stevenson in his report of the sub-committee on the Car- 
bonic (The American Geologist, vol.-ii. p. 248, Minneapolis, 
1888) has suppressed the Dyassic system in North America; 
according to his views and observations the Dyassic fauna 
