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work is so much indebted, found on the road, in the neighbourhood 
of Islington, the flint stone, Plate XII, Fig. 10, which will serve, in 
some measure, to connect these fossils together. On the side may 
be seen, a little magnified, the external surface of the organized body, 
formed of similar inosculating tubes, with those which are seen on the 
surface of the preceding fossil. In the fore-part is seen a section 
of its internal substance, also a little magnified, in which the marks, 
occasioned by the various convolutions of these tubuli, are beautifully 
displayed, being of an opaque grey, whilst the intervening transparent, 
silicified alcyonic matter is of a strong reddish brown ; shewing that 
the red colour belonged to more than one species of the antediluvian 
alcyonic genus. 
The flint fossil, Plate XII. Fig. 7j found in the gravel at Seward- 
stone, in Essex, is evidently of the same species with the two preceding 
fossils. On its superior part, the convoluted tubuli are seen; but 
its inferior part is quite smooth, and appears like the external coat of 
the alcyonium. This part is extended in such a form as to give reason to 
suppose that the alcyonia of this species, like the preceding, were 
supported by a peduncle. 
The flint fossil, Plate XII. Fig. 12, is of very doubtful origin. The 
confused and indescribable mass in the centre, now perfectly silicious, 
I suspect, must have been of an alcyonic nature. Flints, distinguishable 
by the circularly disposed traces observable in the lower part of this 
specimen, are very frequent. 
