60 
The American Geologist. 
January, 1886 
Zittel's Elements of Palaeontology. 
It is announced that part I of the first volume of Prof. 
Karl von ZittePs “ Elements of Palaeontology ” ( Protozoa to 
Mollusca) will be published by Macmillan & Co. within a few 
weeks. The original edition, which appeared last May, is an 
admirable summary of our most recent knowledge of 
palseozoology. The task of bringing out a revised English 
edition was undertaken by Dr. C. E. Eastman, of Harvard 
University, in collaboration with the author and a number of 
the leading American and English specialists. A quantity of 
supplementary notes were furnished by the author and incor¬ 
porated into the translation ; and the various chapters have 
been not only thoroughly revised, but very considerably 
enlarged, so that the work as now planned will comprise two 
volumes of 600 or 700 pages. 
Many original observations have been contributed by the 
American palaeontologists who have aided in the preparation 
of the first volume. We note in particular the additions 
from the pen of Dr. Charles Wachsmuth, who has remodelled 
the entire crinoid and blastoid chapters conformably to the 
latest echinological discoveries; the able revision of the 
Asterozoa Echinozoa by W. Percy Sladen, Esq.; notes on the 
conodonts, by Dr. G. J. Hinde; and the highly creditable 
bryozoan and brachiopod chapters, which have been practi¬ 
cally rewritten by Messrs. E. O. Ulrich and Charles Schuchert, 
respectively. 
Part II of the first volume concludes the invertebrates, and 
its completion will be awaited with great interest. We under¬ 
stand that the following well-known investigators are engaged 
upon its revision : Dr. W. H. Dali, lamellibranchs and gas¬ 
tropods ; Prof. Alpheus Hyatt, cephalopods; Prof. C. E. 
Beecher, trilobites; Dr. J. M. Clarke, remainder of the 
Crustacea ; and Prof. S. H. Scudder, insects. 
It is expected that Profs. O. C. Marsh and A. S. Woodward 
will cooperate with the author in revising and enlarging the 
second volume. The translation of the same, by Drs. East¬ 
man and Merriam, is already far advanced. We shall 
endeavor to notice this work more in detail in a future 
number. 
Underground Temperatures. 
Prop. Alexander Agassiz is engaged in conducting observa¬ 
tions on rock temperature at great depths on Keweenaw point, 
Mich. A recent letter of his, published in the American Jour¬ 
nal of Science for December, contains much that is of interest 
and, as his results diifer so much from the commonly accepted 
figures for the downward increase of temperature, we print 
the letter: 
