400 Miscellanies. 
ken in view of such equivalents, and set forth in the last edition of 
my Text Book, by the additional collections of organized remains, 
made in the months of August, September, and October, of the 
present year, by the students and assistant teachers of this school. 
At the same time I reviewed the Helderberg range, and continued 
my examinations throughout the southern part of the county of Al- 
bany. In truth, every step I take, where organized remains are 
found, and every specimen brought into this school, (several thou- 
sands have already been seen in the students’ lecture rooms,) strength- 
en my confidence in the opinion of Cuvier, and of the other great 
men of the East, that “ organized remans are true indexes to geologi- - 
cal strata.” : : 
The following species, found in connexion with Pennsylvania coal 
beds of Wilkesbarre, Carbondale, &c. by Mr. Hall, myself, and stu- 
dents, have been determined according to M. Brongniart; and he) 
are all open to the inspection of the amateurs of natural science, in 
the natural history room of this school. ag, 
Genus Nevropreris.—Fleaxuosa, gigantea, heterophylla, ele- 
gans, Loshi, Cistii, Lorettii, angustifolia, acutifolia, macrophylla, 
tenurfolia, auriculata, cordata. os 
Genus SrueNopreris.—Latifolia, furcata, trifoliata, artemisae- 
folia, Mantelli, Williamsonis. as 
_ Genus Oponropreris.— Crenulata, Sclotheimii. 
Genus Tarnioprerts.—Vittata. 
Genus Cyciorreris.—Obligua. 
We have several additional speciesmot determined. 
_Note—I hope to be able to furnish the Journal with a description 
of the most important remains, in the collections deposited at this 
school, accompanied with figures. Ihave about sixty species already 
lithographed. Amos Eaton. — 
Rensselaer Institute, Troy, N. Y. Dee. 1, 1832. 
4. Correction of anerror in Prof. Green’s Monograph of North 
American Trilobites ; with additional explanations.—I gave Prof. 
Green several proof sheets of my Geological Fext Book, while 1 
was in the press; in which the genus Brongniartia was ce y 
printed, Brongniatia. As Mr. G. has adopted the erroneous printings — 
it is proper to correct the mistake ; as it is the name of a new g& 
