8;>4 Ihe Allli'ric(l)l ( reologlxf. DecemlxT, 189-,' 
5. On tlie ()cciirreiu-e ul" Artesiiui and UiulcrKroniid Waters in 
Texas, New Mexico, etc. Washington, April, 1892. 
Ill the earlier of these writings I said Mr. ]\larcou had not been 
|)roi)erly understood, and his Grypha>a dilatata and Ostrea marshii 
beds were Jurassic, as he was justified in afhrming from the occur- 
rence of these species. But as a result of later investigations and 
the discovery of these species associated with Comanche faunas, this 
statement was corrected and in the report upon underground waters, 
above mentioned, p, 129, which was sent to the Geologist some months 
before, Mr. Cummins' report w^as published, my conclusions upon the 
geology of Tucumcari were distinctly stated as follows: 
TUK TKIMTY SANDS AND RED ]!E1) J!K(iI(>\S. 
" The writer has twice visited the Mesa Tucumcari and found it a 
most interesting geological remnant of the former area of the Llano 
Estacado. The table or summit described by Capt. Simpson is covered 
with the typical Llano Estacado formation, identical in composition 
and formerly continuous with the sheet which covers the Llano proper, 
some 20 miles distant. Below this is a vertical escarpment of 50 
feet or more of typical Dakota sandstone, resting upon loose sands and 
clays, forming a slope identical in aspect and fossil remains with the 
Denison beds of the Washita Division, which have been eroded away 
from the 400 miles intervening V^etween it and the main body of those 
beds at Denison, Tex. Beneath this is a large de})osit of the typical 
Trinity sands country, of white pack-sands, thin clay seams, and 
flagstones, while the base is composed of the typical vermilion sandy 
clays of the Red Beds." 
Since much of this Texas report was used without C4-edit upon work 
done by myself or my assistants, including ]Mr. Taff, working under 
my direction [First Annual Report 1889, pp. lxxxviii and 106-141] the 
state geologist, with the above passage before him, might have spared 
himself the labor of disjjroving a theory I had Um^ since publicly 
disowned. 
Concerning the age of the Trinity beds of my Trinity division, for 
which Mr. Taff, without statement of authority or reason, substitutes 
the name Bosque, I have always held that they- present a Wealden 
fauna which both in Europe and in this country presents certain 
transitional Jura-Cretaceous features, but is by general agreement 
placed in the Cretaceous and so considered. If IMessrs. Cummins and 
Taff can speak with positiveness on this subject, they are to be con- 
gratulated, for there are several geologists who have had much longer 
acquaintance with the occurrence and problems of the basal Creta- 
ceous in this country, who, after careful years of labor, are still con- 
servative in expression — among these are Profs. Ward, Fontaine, 
White, McGee and myself. 
Your statement on p. 314, that the Gk^n Rose beds were not asso- 
ciated by me with tiie Trinity, but were retained in the Fredricksburg 
division, is a mistake. Tliis was true in my earlier ])ublications, but 
