240 The A?nerica?i Geologist. October, i89!< 
The detailed examination of the Newark system in New Jersey- 
has been completed, and is quite fully reported; but it is hoped to 
present later a more elaborate discussion of some of its problems 
when explorations have been extended for comparison beyond the 
limits of this state. 
Professor Clark contributes a very interesting summary of the in- 
vestigations of the Upper Cretaceous series, as studied by himself 
and his associates during the past five years in New Jersey, Mary- 
land, and Delaware, preceded by a history of the work of former 
observers. w. u. 
Iowa Geological Stirvey, Volume VIII : Annual Report, iSgy, tvith 
Accompanying Papers. Samuel Calvin, State Geologist ; H. Y\ 
Bain, Assistant State Geologist. 427 pages, with 32 plates, 13 figures 
in the text, and six folded geological maps ; Des Moines, 1898. 
This volume comprises administrative reports which give brief 
statements of the progress of the survey last year, with a summary 
of the condition and statistics of production of the mining industries 
and quarrying in the state during the year. The aggregate value 
of the mineral production was nearly seven and a half million dollars. 
Following these reports are papers on the geology of Dallas county, 
by A. G. Leonard; of Delaware and Buchanan counties by Prof. 
Calvin; and of Decatur and Plymouth counties, and on Properties 
and Tests of Iowa Building Stones, by H. Foster Bain. 
In Buchanan, Decatur, and Plymouth counties, exceptionally in- 
teresting problems have been studied concerning the sequence of 
stages or epochs of the Glacial period. The last named county and 
adjoining parts of northwestern Iowa are found to present difficulties 
in correlating the successive drift sheets and loess deposits with those 
of other parts of the state. The evidence perhaps indicates that 
northwestward, in the Missouri river basin, the deposition of the loess 
continued from the time of recession of the ice border at the end of 
the lowan stage until the time of formation of the Altamont mo- 
raine on the margin of the ensuing Wisconsin stage of glaciation. 
The lowan and Wisconsin stages probably occurred very near to- 
gether; but they were far later than the even more closely consecutive 
Kansan and Buchanan stages, which were doubtless several times 
longer ago than the lowan glacial readvance. w. u. 
MONTHLY AUTHORS' CATALOGUE 
OF American Geological Literature, 
Arranged Alphabetically.* 
Bain, H. F. 
Geology of Decatur county flowa]. (Iowa Geol. Survey, vol. 8 
PP- 255-309, pis. 21-24, I map, 1898.) 
*Tliis list includes titles of articles received up to the 20th of the preceding 
month, including general geology, physiography, paleontology, petrology and 
mineralogy. 
