66 The American GeoUxjist. January, is97 
Traces of organic remains frcjin the Huronian (?) series at Iron Moun- 
tain, Mich., W. S. Gresley. Trans. Amer. Inst. Mining Eng., Colo- 
rado nneeting, Sept., 1896; 8 pp. 
Faulting in glacial gravel, W. S. Gresley. Ibid., 2 pp. 
The geology of the Sand hills of New Jersey, W. B. Clark and G. R. 
Shattuck. Johns Hopkins Univ. Circulars, vol. 16, 4 pp., 1897. 
V . Proceedings of Scientific Laboi-atoricN, etc. 
Bull. Mus. Comp. Zool., vol. 28. no. 2, (Geol. Ser. vol. 3), pp. 29-62, 
pis. 1-26. Oct.. 1896. The elevated reef of Florida, Alexander Agassiz; 
with notes on the geology of southern Florida, L. S. Griswold. 
Same, vol. 28. no. 3, (Geol. Ser. vol. 3), pp. 65-91, Dec, 1896. Notes on 
the artesian well sunk at Key West, Florida, in 1895, E. O. Hovey. 
CORRESPONDENCE. 
The age of the California Coast Ranges. Mr. Fairbanks having 
seen fit to offer, under the foregoing heading, certain friendly criticisms 
upon a recent paper by me, on the Great Valley of California, a few 
words in reply may not be amiss, as showing that the real difference be- 
tween our views is not so wide as he seems to imagine. 
To begin with, the criticism seems to have rather overlooked the fact 
that the main object of the paper discussed was a study of the theory 
of isostasy with special application to the Great Valley, and not an ex- 
haustive discussion of the various oscillatory movements that may have 
affected that portion of the earth's crust now occupied by the Coast 
ranges. It was far froui my intention to deny the fact of these oscilla- 
tions, or the former existence of pre-Miocene land masses within this 
area. As a matter of fact, such older land areas are distinctly men- 
tioned on page 424, and elsewhere within the paper. But to speak 
of thesse older land masses as " the Coast ranges," and to assume that 
they held substantially the same relations toward the interior valley and 
coast line that the mountain ranges of that name now do, or have done 
since the close of the Miocene, is a very different matter. 
It may be true, as Mr. Fairbanks suggests, that the discussion of such 
oscillations as he refers to migJit materially strengthen the case against 
isostasy, but it is also conceivable that the discussion of such a broad 
principle may have its value largely increased by a decided tendency 
toward conservatism in the selection of the fundamental data from 
which the deductions are drawn. In the present state of our knowledge 
it does not appear possible to connect these movements with the mor- 
phogeny of the Great Valley in a sufficiently definite manner to add any 
value to the discussion in hand. 
Mr. Fairbanks says that " the Miocene was terminated by one of the 
most marked changes of level recorded in the history of the i-egion. 
This change was in the nature of a great uplift with the formation of 
several new ranges," and with this statement I am in substantial agree- 
ment. Our main difference is purely one of definition. He would include 
