13 
37. Other specimens of petrified wood, from different 
Jocalities: one called hickory stone, from Calvert county, 
Maryland ; another from Mexico, being a piece of petrified 
oak, called there sughero, or the cork tree.—Professor De! 
Rio. | 
38. A tray of petrified madrepores, called petrified buf- 
falo horns; believed to have been found at the falls of 
Ohio. | 
39. Two pieces of bone, apparently of some cetaceous 
animal; from a stratum abounding in marine shells, 60 
miles from Charleston, S. C.—Dr. Thomas. 
40. A curious piece of petrified wood, from the Chock- 
taw country, 100 miles east of Natchez; one end of which 
is black, and the other white.—P. C. Goercy. 

No TVW. 
The fourth Shelf. 
1. Half a dozen specimens of the clay slate, or blaes, 
abounding with impressions of ferns and palms, in the coal 
districts of Pennsylvania. 
(a) Part of a large frond, overlaying the anthracite of 
Berks county, near the sources of the Schuylkill.—Mrs. 
Bailey. | 
(6) Saginaria and ftlices, from the superincumbent rocks 
in the coal tract near Wilkesbarre. ) 
(c) Cryptogamic impressions in the coal slate of Pitts- 
burgh. | 
2. A nodule of argillaceous iron, about the size of a 
small loaf of bread; disclosing, by being split into two 
parts, the stems and leaves of ferns, very distinctly, on its 
fractured surfaces. Derbyshire, England. 
3. A piece of calcareous rock, raised from the bottom of 
the sea, on weighing anchor, near one of the Bahama _ 
keys. It abounds with shells, such as bullas, scallops, and 
