> Ca. ’ Co , re 
ra fa 
nad Fi 
each. The elongation of the tail in our species is 
alone sufficient to distinguish it. We have always. 
been doubtful whether the minute granulations on 
our species were not produced se the sandstone: 1 in 
which it is petrified.. ’ 
Upon what authority the A. Hawsmanni has ison 
considered as a species belonging to the United 
States we cannot determine. In the valuable and ex- 
tensive cabinet of trilobites belonging te the Albany 
Institute, there are a number of specimens labelled 
with this name by Professor A. Eaton. If we mis- 
take not, he mentioned to us that similar fragments 
of this fossil were sent by him to Brongniart, who, 
we understand, is the author of the list of trilobites 
found in the manual of De la Beche. The specimens 
which have been examined, both in the cabinet of 
Professor Eaton, and in that of the Albany Institute, 
are certainly not identical. with the figures or de- 
scriptions published of the A. Hausmann. Profes- 
sor Eaton, in his Geological Text Book, at page 31, — 
thus describes his A. Hausmanni-—* Tail rounded, 
and forming the middle of a circular arc whose cen- 
tre is in the fore abdomen, near the heads covering: 
tubercled or spined. Found in coral rag on’ the 
south shore of Lake Erie. Also, in its underlaying 
grit slate on the Helderberg.”? Some other trilobites 
‘mentioned in De la Beche’s list as occurring in the 
United States, we have not been so fortunate as to 
meet. : | Nght | Sa 
‘ 
