Organic 
Remains, &c. 
176 Professor Sepawick on the 
were found by Professor Henslow, in the Isle of Anglesea. For 
an elaborate description of the accompanying phenomena, I must 
refer to the preceding volume of the Transactions of the Society, 
(p. 407—410.) 
On a portion of one of the indurated cellular masses con- 
taining garnets, [ found the impression of a madrepore of a species 
very common in the mountain limestone. 
In Section 3. No. 2, there are balls and concretions of lime- 
stone, associated irregularly with the hard cellular substances 
above described. In a part of the same anomalous mass, the 
limestone assumes the character of a distinct subordinate bed, 
penetrated irregularly by crystalline matter, resembling that which 
lines the cavities of the splintery jaspideous rock. The limestone 
is always crystalline and granular, and sometimes uniformly 
white; but we may generally trace many cloudy bluish spots 
throngh the mass, which seem to indicate the partial presence of 
the ordinary colouring principle. In those portions of the lme- 
stone which are nearest to the trap, and most granular, impressions 
of organic remains are very rare. Under such circumstances, 
we may, however, sometimes trace the stems, and even the stel- 
lated structure of madrepores in certain parts of the rock, which 
are always of a darker colour where organic remains are present. 
The fact, that such discoloration arises from the presence of 
organic remains, can, im many cases, be established only by 
a comparison of a large suite of specimens. Associated with the 
granular limestone, I found in one place, a considerable portion 
of mica, and a substance resembling compact feldspar, so that 
a hard specimen might easily have been mistaken for a fragment 
of a primitive rock. 
'The lower beds of granular limestone are often of a lead 
colour, and not unfrequently the remains of madrepores, encri- 
nites, and other fossils, appear through the granular mass in the 
