10 % 
the front or middle portion of the buckler, is marked — 
on each side near the oculiferous tubercles, with two 
deep pits producing several irregular pleats or folds, 
somewhat like those on the front of -Calymene Blu- 
menbachii of Brongniart. ‘The cheeks are triangular 
in shape : their lateral edges are terminated by a plain 
raised hem, which corresponds in breadth with the or- 
namented border of the front. The oculiferous tu- 
bercles are very prominent, almost encircled at their 
base by a deep groove, and have at their apices a semi- 
lunar depression. A shallow depression also passes 
from behind each of the eyes, over the surface of the 
cheeks, nearly parallel with the furrow which sepa- 
rates them from the front. 
The buckler is the only part of this very singular | 
trilobite, which has yet been discovered. I have there- 
fore more hesitation in deciding whether it bea Caly- 
mene or not. It has been suggested, that the extrem- 
ity of the tail is furnished with an organization simi- 
lar to the ornament on the edge of the front, and that 
a portion of the ornamented edge in that part is pro- 
duced by the position of the animal; it being coiled 
or rolled up so as to bring the edges of the buckler 
and tail together. If this should turn out to be i 
fact, this trilobite cannot be a Calymene. 
I am indebted to the liberality of Dr. J. E. Dekay, 
of New York, for this very curious species. It occurs 
in a soft gray sandstone, and was found in the State — 
of New York, but its precise locality I was unable 
