IOWA ACADEMY OP SCIENCES. 
39 
supplied with fossils. Without exception they appear to be 
characteristic Devonian forms. As yet, however, the fauna 
has not been studied sufficiently to be specifically listed, but 
the brachiopods are mostly very similar to, if not identical with, 
the species found in undoubted Devonian shales farther north- 
ward in the same state. The cephalopods are represented by 
large forms of Cyrtoceras, Gomphoceras, and Phragmoceras. 
One belonging to the latter genus may prove to be Winchell’s 
P. expansus. Another very characteristic phase of the fauna is 
the non-trilobitic crustaceans, of which a very considerable 
number have been found. They have very close affinities to 
Tropidocaris and Amphipeltis. 
It appears, then, that a well defined Devonian fauna extends 
up to the top of the Hannibal shales in northeastern Missouri, 
at Louisiana especially, and that the “Kinderhook” shales of 
southeastern Iowa, as typically developed at Burlington, and 
as corresponding in great part to the Hannibal shales, carry no 
other remains than those of pronounced Devonian types. The 
upper part of the section usually regarded as Kinderhook at 
Burlington, in fact all the thin limestone and sandstone bands 
down to the great body of argillaceous shales may be more 
properly regarded as the equivalent of the Chouteau limestone, 
that is, the uppermost member of the so-called Kinderhook in 
Missouri. 
(S) Upper Limit of the Louisiana Fauna . — One reason that the 
fauna of the Chouteau (original) limestone has not been better 
understood than it has, in its relation to the faunas occurring 
lower in the so-called Kinderhook, and higher in the Burling- 
ton limestone, has been that in the localities where the lower 
Carboniferous has been most thoroughly and widely studied 
along the Mississippi river, the Chouteau, as commonly recog- 
nized, nowhere crops out along the great stream, except, per- 
haps, in the vicinity of the town of Louisiana where, under 
the typical Burlington, there are nine feet of earthy limestone 
which has been considered a part of the latter, but which is 
now believed to be the attenuated edge of the Chouteau, or its 
equivalent. In the same county the Chouteau attains a maxi- 
mum thickness of twenty -five to thirty feet. 
In the table given there is: (1) The species that come up 
from below to the base of the Chouteau, (2) those starting in 
the Chouteau and ranging upward, (3) the forms starting in 
the basal member of the Burlington limestone, and (4) the 
