Review of Recent Geologiral Literature. 197 
to the Bame horizon as certain parts of the Old Red (Devonian) sandstone 
of Scotland. It is well known that the Old Red of Scotland and the Devon- 
ehire formations of England present such different characteristics alike 
petrographic and paleontologic, that in Great Britain no synchronism 
whatever between these deposits can be affirmed. But, M. Lohest assures 
us, this synchronism is now rendered po&slble by the discovery in Belgium 
of an ichthyic fauna comparable to that of the Old Red mingled with a 
molluscan fauna analogous to that found in Devonshire. 
Our author also discusses the mooted question whether the Old Red 
sandstones were deposited in salt water or in fresh. "With good reason he 
affirms that the presence in fresh water of our modern ganoids whose 
affinities with their paleozoic predecessors are so close, does not neces- 
sarily imply for the former an identical habitat. All our fresh-water 
fauna had probably, more or less remotely, an origin marine." But M. 
Lohest argues that the correlation of the different strata mentioned above 
by which correlation mollusca, certainly marine, are associated with those 
ancient ganoids makes a fresh water habitat for the latter extremely im- 
probable. 
By his comparative study of the British and Belgic Devonian, M. Lohest 
is led to propose an explanation of the want of concordance in certain types 
of fishes occupying successive deposits in the Belgian formation. 
He suggests that to assume an alternation of deposits as between Scot- 
land and Belgium explains the difficulty. The Scotch formations bio- 
logically fill the hiatus between the older and later deposits on the conti- 
nent; as if by successive changes in level the ganoid and dipnoid fauna 
had migrated first from Belgium to Scotland and then back again to 
Belgium. 
A second brochure by the same author, (M. Lohest,) issued at the same 
time and place as the memoir just considered, announces the discovery of 
what is esteemed "the most ancient amphibian known" to science. A 
fragmentary skeleton from the upper Devonian is figured and briefly 
described. 
T/ie Iron Ores oftM Penvkee-Gogebic Series of Michigan and Wisconsin 
— With Plate. By C. R. Van Hisk. (From the American Journal of 
8<ienc9 for January, 1889.) The author treats first of the series of rocks 
in which the iron ores occur — a series running across the country in » 
direction approximately east and west, from the vicinity of Numakagon 
lake, Wis., to Gogebic lake, Mich., a distance of more than 80 miles. The 
series has been tilted to the north at an angle of 60"^ to SO'', rests on a com- 
plex of granites, gneiss and green schists, and is overlain by eruptives of 
the Keweenaw series. There are four members to the Penokee-Gogebio 
series,— ^rjt^, cherty \\m^i>Xone,— second, feldspathic quartz-slate, — third, 
non-fragment al sediments 800 feet thick and known as the iron-bearing 
member,— /owr^A, a series of greywackes, greywacke-slates, and mica- 
schists and slates, in the aggregate several times tljicker than the other 
three members combined. 
The iron-bearing formation is traversed by dykes of greenstones or oth^^r 
