Geology and Natural History. 317 
evidence of being the result of much investigation. It discusses 
the relations of the various genera of Carboniferous corals and 
gives descriptions of many new species. arge number of 
development as well as distinctions in structure. 
eologie von Bayern (Bavaria), von Dr. K. W. von Gum- 
BEL, Ist part: Elements of Geology, and Ist “ Lieferung,” 208 
pp-, with numerous illustrations in the text. Kassel, 1884 (Theo- 
dor Fischer).—-This volume is the first portion of an extended 
work on geology by Dr. von Giimbel, and includes an account of 
the constituents of rocks, and the methods of investigating them, 
themselves through part of the series. The cuts are illustrations 
of the optical characters of the minerals and rocks; and a large 
part of the rocks described are thus illustrated. The wor 
promises to be an important contribution to geological science as 
well as a valuable text-book. : 
teroscopic organisms in the Bowlder Clays of Chicago 
and vicinity; by Messrs. Dr. H. A. Joanson and B. W. AS. 
ull. Chicago Acad. Sci., 1884.\—The authors of this paper 
microscopic dises 1-85th to 1-250th of an inch in diameter. 
The facts were the occasion of the recent appointment of a com- 
full of bowlders, of various sizes up to several cubic yards, many 
with “ice-markings ;” and some of the smaller are a carbona- 
ceous shale which is apparently identical with that of the Upper 
Devonian ; like that it burns with a bright clear flame giving out 
a strong petroleum odor. : 
M as, in a note appended to the article, states that he 
de cla 
clay,” from Litchfield, in Cen 
‘are marine and are supposed to come from Cretaceous beds. 
a clay of the lower drift, from Bloomington, Illinois, at a depth 
