GEOLOGICAL MAP AND SECTION OF THE ROCKS OF MISSOURI. 541 
dicates that the so-called Eozoon of Chelmsford is not of animal 
origin, it at the same time casts discredit upon the organic char- 
acter of the ‘‘Eozoon” generally, and fixes the burden of proof 
upon its advocates. It also certainly suggests that the resem- 
blance which the ‘‘ Eozoon” has to animal structure is, like that 
of Dendrites to vegetable forms, merely the result of chemical 
agency. 
REMARKS ON THE GroLoGIcAL MAP AND SECTION OF THE Rocks 
or Missourt.— By Pror. G. C. SwaLttow 
Ir was his object to put on record some of the general results 
of the Geological Survey of Missouri made by himself and his able 
assistants (one of whom, Dr. B. F. Shumard, is now dead.) Since 
the interruption of the survey by the late civil war there has been 
no opportunity offered for the publication of the results. 
The survey was most minute and carefully made, and the re- 
sults the same as represented by the section and map before us. 
The boundaries of the formation save in eight or thirteen counties 
are accurate and all the formations are as delineated by the section 
running through all the great systems known to American geology. 
Some of the results in Economical Geology were mentioned. 
There are twenty-seven thousand square miles of Coal Measures 
containing at least twenty coal beds, one at least of the block 
coal. Large deposits of specular, hematite, bay and spathic 
ores were mentioned. The mineral regions containing mines of 
lead, zine, cobalt, nickel and copper cover an area of about eight 
thousand square miles; all but two hundred square miles in the 
Magnesian Limestone series (of the Potsdam and Calciferous ages) 
and two hundred square miles at Granly in the lower Carbonif- 
erous rocks. Lead and zine often cut the coal beds in their 
vertical veins. 
The Potsdam Sandstone rests nonconformably upon the Azoic 
stratified slates of Pilot Knob. Hence Pilot Knob. 
Prof. E. W. HILGARD inquired of Prof. Swallow whether the chalky 
siliceous beds in southeastern Missouri, conjectured to be of cretaceous 
age, did not occasionally contain grains of glauconite, black sand and 
obscure casts of shells. 
Upon Prof. Swallow replying in the affirmative, Prof. HILGARD S tated 
that while such materials were altogether foreign to the Cretaceous pars 
of the adjoining states of Arkansas, Tennessee and Mississippi, a narrow 
