Hitchcock.] 
34 
[May 16, 
date of Jan. 28, 1862. It is easy to trace the progress of the print- 
ing from the volumes themselves. On page 386 is a note added to 
the galley proof which indicates that everything up to that point, 
including the account of the Georgia slate, had been printed by 
July 20. By August 10, the whole of Part II, or everything re- 
lating to the Paleozoic rocks with the exception of the appendix 
noted above and the general sections, had been printed. After 
that date no alterations could possibly have been made to the text. 
But according' to the principles employed by Mr. Marcou in his 
memoir, the date of the publication of Part II does not depend 
upon the issuance of the volumes in bound form. Excerpts that 
have been distributed or exhibited to scientific men before the ap- 
pearance of the bound volume, are regarded as having been pub- 
lished. Thus he says of the general map in volume 2, “The map 
had two editions. The first one, distributed in December, 1861, 
contains,” etc. He allows that this map was published in 1861, 
Then the whole of Part II must have been published as early as 
September, 1861, since it had been distributed and exhibited to 
scientific men just as much as the map had been. 
The reason why the effort is made to show that the date of the 
'.publication is incorrectly stated is that there is a question of the 
priority of the proposal of the name Georgia slate. It seems that 
on the sixth of November, 1861, Mr. Marcou, at a meeting of the 
'Boston Society of Natural History, in a communication upon the 
“Taconic and Lower Silurian rocks of Vermont and Canada” de- 
voted a few lines to the description of a band of rocks which he 
named the Georgia slates , referring them to the middle of the Ta- 
-conic system. The remarks were printed in December, but the 
blackboard illustrations did not appear till 1880, and most of these 
he acknowledges in the memoir cited at the beginning of this paper 
to have been erroneous. Because the Vermont report was not pub- 
lished till 1862, and his remarks were given orally in November 
1861 (printed in December), Mr. Marcou claims to be the originator 
of the name of Georgia slates as applied to a geological deposit. 
According to the principle of Mr. Marcou, as explained above, my 
description printed in July was published as early as September, 
and therefore has the priority over the November communication. 
But I will not base my claim upon this supposed earlier publica- 
tion. Credit for original suggestion is based as much upon its 
correctness as determined by later explorers, as upon earlier pub- 
