24 Contributions to the Geology of ‘Texas. 
In regard to the organic character of these strata, the opinion 
expressed in my first paper has, on the whole, been confirmed by 
later researches, and is at present supported by a much greater 
number of facts. Most of the fossils belong to known types of 
the cretaceous formation. The number of species, however, ex- 
actly identical with described species is very lim mited. By com- 
paring the fossils with those of the different divisions of the cre- 
taceous formation as they are established in Europe, it appears 
that the rocks of Texas do not agree in any particular with re- 
ceived divisions. It is evident only that they belong to the 
rt of the scretacaate formation, for there is a complete 
absence of all the characteristic forms of the gault and lower 
greensand, and on ie other hand, there is an undoubted analogy 
with the organic character of the "chalk and chalk marl, 
Notwithstanding the considerable thickness of the whole sys- 
tem of strata, (which cannot be less than about eight hundred 
feet,) it seems impossible to divide it into different groups. Nei- 
her the mineralogical constitution of the rocks, nor the distri- 
bution of the organic remains allows of any such division. By 
a comparison of these cretaceous deposits with those of New 
Jersey, and other localities on the Atlantic coast, the oe 
in the zoological character appears hardly less striking than t 
difference in the mineralogical constitution which was alluded to 
before. Except the Pecten quadricostatus and the Hxogyra cos- 
tata, (the latter being rare in Texas, ) I do not know of any other 
identical species, and the number of closely allied species is not 
very small. A little more analogy seems to exist with the creta- 
ceous deposits of Alabama and Western Tennessee. At least a 
species of Ammonite, common at Prairie Bluff in Alabama, oc- 
curs also in Western Texas, and a species of Hippurite is closely 
allied to a species which I found at Austin, Texas, if not identi- 
cal with it. 
The analogy of the Texian strata with the cretaceous deposits 
on the Upper Missouri, is hardly greater than with those on the 
Atlantic coast. Not one of those beautiful species of Scaphite, 
Baculite and Ammonite, discovered by Nicollet, and described by 
Morton,* has been met with in Texas 
The entire absence of the Belemnites mucronatus, and eve 
other Belemnite, is one of the principal negative characters of 
the Texian strata 
It is more — to define in a few words, the positive char- 
acter of the Fau 
All the aa pate a very few, (which form perhaps two 
new genera,) belong to genera which are either peculiar to, (as 
for instance, Baculites, T'urrilites, etc.,) or are represented in the 
cretaceous formation. 
*Journal of the Acad. of Nat. Sc. Philad., vol. viii., p. 2. 
