Review of Recent Geological Literature. 181 
guella, Acrotreta and Modiolapsis. This is the third fauna of the 
Upper Cambrian reported from that island; the others being Peltura, 
collected by the late Dr, Homyman, and Dictyoruna, collected by Mr. 
H. Fletcher. The Tremadoc species are shown on a plate at the end 
of the article. 
Two tables in the text show the development of Acrotreta in the 
~Cambrian and Ordovician, and the distribution of Acrothele. 
The Geology of Cincinnati, by Joon M. Nicktes. (From the Journal 
of the Cincinnati Society of Natural History, Vol. XX, No. 2, pp. 
49-100, I map.) 
Careful studies of limited areas are always valuable, and doubly so 
when they treat of typical localities. The paper under consideration 
deals with the Cincinnati period as exposed at Cincinnati, the type 
locality, and so much of the underlying Trenton as is exposed there. 
A brief sketch of the topography showing modifications produced by 
glacial action, and pre-glacial watercourses, is followed by a careful 
and accurate historical resumé of the literature pertaining to the 
geology of the region under discussion and the matter of nomen- 
clature. The term Cincinnati or Cincinnatian is shown to have sur- 
vived by a process of natural selection. The divisions, or groups as 
they are called in the paper, of the Cincinnati period, are recognized 
as the Utica, Lorraine and Richmond, each easily separable by faunal 
and more or less marked lithological characteristics into stages or 
hemere. Those of the Utica are designated as Lower, Middle and 
Upper, with faunal designations also. For the subdivisions of the 
Lorraine, both faunal and geographical designations are proposed. 
The latter in descending order are Warren, Mt. Auburn, Corryville, 
Bellevue, Fairmount and Mt. Hope beds. The Richmond, not exposed 
in the immediate vicinity of Cincinnati, is divided into Lower, Middle 
and Upper subdivisions. Under each subdivision is given its litho- 
logical and other features and a list of the species of fossils found 
therein. The large number of species listed in the paper, nearly goo, 
shows how industrious the collectors of Cincinnati and the surround- 
ing region have been in their search for the paleontological treasures 
entombed in their hills. The region is noted for the fine preservation 
of its fossils. The paper cannot but prove helpful in the study of 
the Cincinnati period in other sections of this country. 
The map is based on the recent topographical map of the U. S., 
Cincinnati sheet, issued by the U. S. Geological Survey, leaving out 
the twenty-foot contour lines, but retaining the 100-foot lines, and 
indicates the location of all outcrops of importance. A sketch map 
of the pre-glacial drainage, printed in the text, is copied from Gerard 
Fowke’s without acknowledging the source, an omission which the 
reviewer knows to be the fault of the printer, not of the author. 
It appears that this article is filling an existing need. Professor 
Prosser has sent for a lot of copies to be used by his classes in the 
