151 
belonging to an animal of the genus alcyonium, I do not in the least 
doubt, nor that the perpendicularly disposed lamellae are the muscu- 
lar organs, by which the animal was enabled, as in the fossil just de- 
scribed, to elevate the more central part of its base, and thereby 
produce that vacuum by which its attachment to any particular body 
would be secured. 
In two several parts of the stone, cavities are also observable, which 
seem to be the moulds formed on the outer surface of the animal, as 
the preceding appeared to be formed on the inner. On the inferior 
surface of these cavities, which are circular, radiating striae are ob- 
servable, and which, apparently, answer exactly to the disposition of 
the inferior part or basis of the lamellae, already described as forming 
the projecting part in the cavity of the supposed animal. This flat 
circular surface, I am therefore disposed to consider as the impression 
formed by the inferior flat part of the alcyonium, corresponding with the 
inferior surface of the fossil already described, Plate X. Fig. 1. 
Previously to my quitting this tribe of zoophytes, I shall avail 
myself of the opportunity afforded me by my friend Dr. Menish, 
of placing before you a very curious fossil from his select and elegant 
collection. This fossil, which is represented Plate XII. Fig. 3, is chiefly 
composed, judging from its weight and hardness, of flint, and was 
found in Essex. It is formed of roundish but rather flat bodies, in 
the centre of each of which is a small depression. From two of these 
bodies being, even at present, connected by a small process, and by 
small protuberances, like the terminations of such processes, appearing- 
on the sides of several of these bodies, there is great reason to sup- 
pose that they were all originally thus united. From all these circum- 
stances, I trust that it will not be too much to presume, that this fos- 
sil is of the same nature, if not of the same species, with those which are 
represented Plate VIII. Fig. 10. 
The almost transparent chalcedonic alcyonite, from France, Plate 
