ae. Sic ES gall Ae ee So UN aa Sarai ks = is hepa eA tee. = 
oe om BOs oid peta 
1893.] Recent Literature. 247 
period, Florida, so far as it was elevated above the sea, was an island 
separated from the mainland by a wide strait, is here first demonstra- 
ted. It is also shown that the strata are probably gently folded 
lengthwise of the peninsula, and that in the trough now occupied by 
the “lake region ” of Florida in Pliocene time a large lake probably 
existed, to which the name of De Soto has been applied. The age of the 
remains of fossil vertebrate animals, which in south Florida are asso- 
ciated with the so-called “ pebble phosphates,” is here definitely deter- 
mined.” i 
After discussing by States the character and distribution of the 
Atlantic Neocene, a chapter is devoted to the consideration of the 
general geological movements and fluctuations of land, sea, currents, 
and water temperatures which appear to have been concerned in pro- 
ducing the characteristics described. 
“Tn like manner the Neocene geology of the Pacific coast has been 
treated, and in addition to that of California, Oregon, and Washing- 
ton, a synopsis of data relating to British Columbia has been included, 
together with a summary of what is known in relation to Alaska 
during this epoch. The latter discussion contains a large amount of 
material extracted from unpublished notes covering some fifteen years’ 
study and exploration by W. H. Dall in the Alaskan region, and 
therefore adds materially to the sum of our knowledge in regard to 
that part of the United States. 
“The Great Interior region of the west is then taken up, and a sum- 
mary of our knowledge in regard to its Neocene geology is brought 
together for the first time. While this is necessarily far from perfect, 
the very fact that such gaps exist will stimulate the collection of infor- 
mation to supply the missing links. 
“The essay closes with a list of names proposed for geological beds, 
groups, and formations in the American Cenozoic strata, and a descrip- 
tion of the data upon which the coloration of the general map is 
b. d 9 
The work while an eminently important and useful one, is very 
unsymmetrical, as the authors themselves recognize. They are very full 
in describing the formations that they have seen, those of Florida, for 
instance, and deficient in those which they have not seen, as the lacus- 
trine formations of the interior. The latter yet remain to receive ade- 
quate treatment from the U. S. Survey, since to do this requires the 
aid of a competent paleontologist of the vertebrata. 
The geological map of Florida contained in this volume expresses 
clearly the latest discoveries in that state. The coloration will surprise 
