* 
F. B. Meek—Fossils of the Illinois Geological Report. 369 
intervals between our coal-seams are not constant. I learn 
from Profs. Dawson, White, Cox and Worthen, our most 
experienced coal geologists, that similar examples to those I 
have cited are not uncommon in the coal fields which they have 
so carefully studied.* 
The fall 
seems to me, the evidence is varied and abundant that this 
subsidence was often very local, and that in the long interval 
were sometimes warped and folded in the most local and com- 
plicated way. It is also apparent that the deposition of the 
materials forming the strata of the Coal-measures was often 
quite irrecular. This is conspicuously shown by the limited 
reach of the great sandstone wedges which sometimes locally sep- 
arate or replace the more constant elements, the limestones, 
shales and coal-seams. In some instances these beds of sand- 
th 
deposited, Just as they do at the mouth of the Mississippi, where 
the displacement results in the formation of “mud-lumps. 
formate 
ART. XXXI.—WNotes on some of the Fossils figured in the recently- 
issued Fifth volume of the Illinois State Geological Heport ; by 
F. B. Mex. 
[Continued from page 19%.] 
Actinocrinites, Cyathocrinites, Codonttes, etc. ; 3 late 1x.—Most 
eu is plate were drawn to illustrate the re- 
of Natural Sciences, some years back. 
€nces to these ficures are ae in that article as reprinted in 
* See also the report of Prof. Ramsay, in the Report of the Coal Commissioners 
(England), vol. i, pp. 121 and 145, : 
