150 REPORT OF THE AMERICAN COMMITTEE. 
graphic systems which do not coincide in beginning and ending 
with the stratigraphic systems of Europe. 
Dr. S. F. Emmons suggests as to colors, three fundamental 
colors or tones of one general color to be assigned to, 1, crystal- 
line or granitoid; 2, porphyritic or intrusive (which have con- 
gealed slowly and under great pressure) ; and 3, surface flows 
which have congealed rapidly and under atmospheric pressure. 
The darker shades to be assigned to the more basic, atid the 
lighter to the more acidic. 
Prof. J. D. Dana, Sir J. W. Dawson, Major Powell, Dr. T. 
Sterry Plunt, Prof. Jos. L. Le Conte, Dr. Emmons, Prof. Geo. 
H. Williams, Prof. C. H. Hitchcock, Prof. N. H. Winchell and 
Prof. B. Emerson answer in a more general way. Of these five 
would accept the decisions if once made, and a sixth would do so 
down to divisions of the third order. 
Of the above suggestions there is no such unanimity as to 
enable one to reach any opinion as distinctively American. The 
more important desire seems to be the change of the word Group, 
from its position as the denomination of the largest division. 
Of the others some are of minor importance and some are 
merely provisional and tentative, the map of Europe being the 
project selected for testing them. 
Others of these more general answers to this question here fol- 
low, together with what seemed to be the most important state- 
ment of those whose opinions have been just quoted, and which 
could not for obvious reasons be introd uced into the synoptical table. 
Prof. J. D. Dana : " If the scheme pp. 49 and beyond were 
the latest proposition, I might discuss it, but as it is not, I do not 
feel like saying much without consulting with others. I see in 
Cappellini's Report of the Geneva meeting in August, 1886, 
the remark that the French would put 'series' above ' group,' 
just reversing the scheme of 1885. I find in Renevier's little 
brochure on the 1885 Berlin meeting that at the Zurich confer- 
ence, it was proposed to make the Systhne Silurique include No. 
4, Cambrian; No. 5, Ordovician ; No. 6, Silurian ; a good idea, 
and that this idea will go to the Congress of 1888 from Switzer- 
land." * 
* [Prof. Dana will find both these ideas referred to on pp. 51 and 91 respect- 
ively of tlie American Committee's Report on the Congress at Berlin. As to the 
first, Prof. Dewalque's committee expressly left the decision to the Berlin Con- 
