i Tak ic 
Geology and Natural History. 505 
ing of oa: larger of the cavities is to be referred to ei horizontal 
moveme whi ch resulted in the elevation of the 
mation of the zine spe pees and then from this there eee 
with the calcium carbonate, the formation of the zine carbona 
the zinc sulphide there is also to be recognized that which has 
resulted from the alteration of limestone, and by direct deposit 
. from solution. 
Dr. 
Sohmidtia memoir, from which the anere facts and accom- 
panying plate have been taken, is of great interest both to the 
theoretical and minin geologi 
uation of the valuable work by the same oun on the lead 
mines of Missouri, published in 1874 in ection with the Re- 
port on the Geo ogical Survey of Mae pa noticed in vol. x, 
1875, of this Journal. 
2. ’ Geological Map of the United States, compiled by C. H. 
Hrrcncock ; issued both in sheets and on "rollers, New York, 
“It is made for a wall map,” and a parently chiefly to serve the 
purpose of ihe lecturer, the details being few and the style of 
work coarse compared with what w e find on fore reign geological 
mee of like size. The facmatinas distinguished embrace three 
divisions under the Tertiary ; the Laramie, Cretaceous and Jura- 
rias under the Mes keg three under the Carboniferous; one 
f 
sentence, we pubcne is 
Am. Jour. 3c1. satan yeti ihe, pe ee 126.— 
