X 
upon further examination was found to contain Foraminifera. It is somewhat 
lenticular, and has a maximum thickness of about four feet, its average 
thickness being perhaps about two feet. It weathers into a soft brownish 
substance, superficially resembling bathbrick. It is essentially a bryozoal 
limestone, largely formed of beautifully preserved Fenestellidce, in which 
genera allied to Folypora and Fenestella are abundantly represented. 
The genus Stenopora is plentifully distributed throughout the lime- 
stone in the form of pencil-shaped types as well as of flat encrusting varieties. 
Fragments of bracliiopod shells, mostly Froductidce, as well as of lamelli- 
branch shells, and small complete shells of gastropods and valves of ostracods, 
are also numerous in the limestone. At the Katawba Vineyard large and 
more or less perfect shells of Furydesma cor data, Aviculopccten, and 
Platyschisma, are associated with the Foraminifera. At the above locality 
numerous specimens of Nubecularia can he seen encrusting the inner surfaces 
of the valves of Aviculopecten. 
The limestone, when slightly weathered, shows on its surface abundant 
milk-white shells of Nubtculuriu, sufliciently large to he easily seen without 
the aid of a pocket lens. Where weathering has proceeded further, the 
Foraminifera are represented only by hollow casts 1 in a soft greenish-brown 
rock, which does not effervesce in hydrochloric acid, and which represents 
mostly the siliceo-felspathic portion of the limestone. Such a rock, when 
passing from its original calcareous condition to its present weathered and 
non-calcareous condition, does not necessarily set free the foraminiferal shells 
from the enclosing matrix. 
Several of the Foraminifera herein described were, nevertheless, 
obtained by Mr. Chapman, by washing the earth collected by Mr. Eustace 
Wilkinson from near the outcrop of this limestone ; but it is likely that such 
shells were derived from the clay shales associated with the limestones rather 
than from the limestones themselves. 
As regards the conditions under which the Pokolbin limestones were 
formed, the geological survey of the district shows that they were developed 
close to the shores of high volcanic islands, rising with steep slopes above the 
surface of the shallow sea belonging to the Lower Marine Stage of the 
1 Attempts were made at the Geological Laboratory at the University to obtain solid casts of these hollows 
by baking the weathered rock in Canada balsam, and then dissolving out the siliceo-felspathic material with 
hydro-fluoric acid, but the pseudomorphs in balsam obtained by this method were not sufficiently sharp in 
outline to make them of use for descriptive purposes. 
