20 
(6) The matrix of rock from which the ammonite was 
separated. 
(c) Ammonites ground away and polished, so as to show 
the internal structure, and the chambers filled with spar, 
&e. 
(d) Ammonites, consisting of pyrites, or the sulphuret 
-of iron; in beautiful condition. Some of them were taken 
from a depth of two hundred feet under ground. —Thomp- 
son and Lester. 
14. Fossil spirorbis, or snail; from a bog near Dublin, 
in Ireland.—J. K. Rodgers. | 
15. Fossil bivalve mollusca; from the black marble of 
Galway, in Ireland; apparently a mytilus.—J. Dick. 
16. Another Galway specimen ; being pyrites, or splen- 
_ did sulphuret of iron, in crystals, distributed over the sur- 
face of a cardite.—J. Barnes. 
17. Enormous scallop-shells, in wacke, four inches ad 
a half in diameter. North-west Coast of America.—Rey- 
_ nolds. 
18. Curious concretion of ied mussel-shells, in aaa. 
Columbia River, North-west Coast.—The same. _ 
19. Part of a belemnite, nearly five inches long, and 
more than an inch in diameter. Weymouth, England. 
20. Polished marble, displaying fine forms of madre- 
pores. E:ngland. 
21. Fossil clam, two inches and a half bneeat? from a 
depth of two hundred feet beneath the surface. Point 
Petre, Guadaloupe. 
22. Beautiful impressions of leaves in clay. Locality 
not noted. 
23. Petrifactions of the cypreea pediculus, and other 
molluscas, in compact lime-stone. France. 
24. Celleporite, in calcareous spar. Curious. Island 
of Jamaica. Za 
25. Fresh water and oceanic shells; from Upper Geor- 
gia, where they form, in.a loose and detached state, exten- 
‘sive strata.—D. Meriwether. 
