"94 Frazer on Int. Cong, of Geologists. 
The international committee adopted the suggestions of the 
Bologna Congress as to the colors to be employed, and decided 
in the cases left to its judgment, (a) to represent the Carbonic 
system (or Permo-Carboniferous) by a gray color in three dis- 
tinct shades; {^b) to assign to the Devonic system shades of 
brown; (c) to assign greenish gray to the Siluric; (o?) to rep- 
resent the eruptive rocks by seven tints of red. Subsequently 
to the Berlin session this committee decided, as recommended 
at Bologna, to employ low^er case Roman letters to distinguish 
the terranes of sedimentary, and small Greek letters those 
'of eruptive origin. The lesser divisions were to be made 
by small figures used as indices, thus: a', a^, a^, were lower, 
middle, and upper Archean, m , m , m , m , for the Ter- 
tiary, etc. 
In the Greek letters i/ stands for lavas of modern volcanoes, 
and v' for tufas and out-throws from said volcanoes, etc. 
The international committee on the unification of nomencla- 
ture made a careful report based ujDon the sentiments expressed 
at the Congress of Bologna, and proposing solutions for many 
of the difficult problems of the subject. It added to its report 
in the same spirit the scheme of Prof. Lossen for the classifica- 
tion of the crujDtive rocks. 
This scheme, as well as the final arrangement of the Cam- 
brian, the division of the Archean, the decision as to the place 
of the Permian, etc., were simply offered in order that some 
project might be formulated and the way prepared for intelli- 
gent discussion. 
great universities and many of the libraries of tlie United States and the 
government institutions are ah-eady on the list, but the complete number 
should have been disposed of long ago. When it is considered that this 
map consists of 49 sheets, seven in breadth and seven in length, which 
when put together will cover an area of i2x 11 feet more or less; that it 
will be a far more accurate topographical and geographical map than 
exists at present; and that the newest determinations of the government 
geological surveys of Europe will be placed upon it, its cost ($26.00 to 
individuals and $21.00 to public institutions, everything paid) seems tri- 
fling. "Will not the readers of this forward to Dr. Persifor Frazer, .201 
South Fifth street, Philadelphia, the names of enough subscribers to take 
up the remaining 25 copies, and thus relieve the committee from the ne- 
cessity of withdrawing the name of the United States from the list of 
*' great states" subscribers? P. F. 
