a. ae 
Description of a new Trilobite. 167 
Arr. XVII.—Description of a new Trilobite ; by Jacop Green, 
M. D., Professor of Chemistry in Jefferson Medical College, — 
Philadelphia. 
Catymene Puuyctarnopes.*—Green. 
Clypeo semilunari, lobis inflatis valdé punctulatis, anticé rotun- 
atoco; cauda ——? : 
I nave been for a long time expecting to find among the trilo- 
bites of North America, a species analogous to the C. variolaris, 
which is sometimes met with among the fossils at Dudley in Eng- 
land. Its association with the C. Blumendachii at that locality, and 
the occurrence of that species in such numbers in the transition 
limestone so extensively spread over the United States, induced the 
belief that it would sooner or later be discovered in our rocks. 
Dr. William Blanding of this city, has recently received from 
Springfield (Ohio,) a number of very perfect specimens of the €. 
Blumenbachii and other fossils. In this rich parcel I had the pleas- 
ure of discovering a fine fragment of the buckler, of a species not 
very unlike the C. variolaris of Professor Brongniart,—Plate I, 
fig. 3, A,—the original of which came from Dudley, and is said to 
be now in the collection of Mr. Johnson, of Bristol, (Eng.) 
Nearly the whole of the buckler of our species is perfect, in the 
specimen I have examined. ‘The middle lobe is large, and very 
prominent: there are no folds or tubercles upon it, as in the C. 
Blumenbachii, or the C. macrophthalma, but the whole of its sur- 
face, as well as that of the cheeks, is covered with distinct, rounded 
grains, or warty pustules. The C. variolaris is also furnished with 
a similar structure, but Prof. Brongniart states that the pustulations 
in that species, are all pierced at their summit with a small hole, 
like the tubercles on the genus Cidaris among the Echini: this is 
not the case in our species, the tubercles being all imperforate; they 
resemble exactly in this respect those on the shell of the Echinus 
mammillaris of Lamarck. 'The whole contour of the cheeks or side 
lobes of the buckler, cannot be made out from our fragment ; they 
no doubt, however, form spherical triangles; each cheek is divided 
by a deep groove into two lobes; the portion of the lobe nearest 
* Phlyctainodes—from the Greek, for pustulated. 
