T1i(l)i(ix. 1 rni>i (I ml 'I It I'd tn Tt-fiO^. — ^Iiircon. •> i 5 
also for the Geological Sarve3\ Why did not Mr. I'lmimiiis send 
his collection to professor Hyatt, at Cambridge, to compare what 
he got with the fine specimens of Mr. Hyatt? 
As it is, the list of fossils, published b^'Mr. Cummins cannot be 
used. Ishallonlj^ say.thatit issimply impossililc to find together in 
the same bed the G rypliiKi dllatntd var. titiiniir(in\\\\x\\ t\\vGryi>lin(i 
pltrhcri and the E.voqjjni tcxauK. Either the fossils determined 
by Mr. Cummins are incorrectly referred to species entirely difier- 
ent, or b}' some accident Mr. Cummins" specimens have been care- 
lessl}' packed up and the labels have become somewhat mixed or 
changed from one packet to another. 
Mr. Cummins insists with great force on his discovery in the 
top bed of the Tucumcari mountain, of a fragmentary leaf of a 
dicotyledonous plant called Stcmilvt dm/,-' i. which he describes 
and figures at p. 210. Until now.he says, no angiospermous leaves 
have been found in older strata than the Cretaceous. and '-a single 
specimen in certain cases is sufficient to definitel}' determine the 
age to which the strata belong. " 
Fossil leaves of Angiosperms have been found, some time ago. 
round Fredericksburg, A'irginia, in strata called the Potomac 
formation, which is regarded bj' some geologists as l)elonging to 
the lowest beds of the Wealden, and b}^ some others as old as the 
Purl)eck formation or upper Jura of England. A leaf resembling 
in the outline a leaf of sassafras has been found in the Potomac 
formation of Virginia, similar to the leaf found at the Tucumcari. 
So there is nothing very new in the discovery of a leaf of 
dicot^'ledouous plant in the Jurassic bed of the Tucumcari 
mountain. 
I have showed before (1'iiE A.mehican (jrKoL(»<;isT. Dee., ISSf): 
"Jura, Neocomian and Chalk of Arkansas,"' pp. ;]57-:>G7 ) that 
the Trinity beds of Arkansas contain a fauna entirely Jurassic, 
and that they belong to the Jura system. It seems, according to 
the observations of Mr. Robert T. Hill, that the upper part of 
the Tucumcari strata, al)ove the horizon of the Gri//>/i<> ,i tii<iiiii<<iri. 
is related and of the same age as the Trinity beds. 
In resume, the supposed Cretaceous age of tlu' 'i'ucuineaiM stnMa 
is an error; not so great as the one of Messrs. James Hall, Shu- 
mard. Meek and Newberry, who synchronized them with the 
Dakota division of the upper Cretaceous. l)ut ib no less a grave 
one, for il displaces ;i whole system of rocks from its position Just 
