PLATE IX. 
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Fig. 1, A flint, from a gravel-pit. In this fossil are seen the ramifying filaments round 
the central opening ; with the cortical part, under which these filaments seem 
to pass. 
2. Is a silicious alcyonite, the surface of which is reticulated, except where part of 
its original external coat remains. The fossils depicted. Fig. 6, 9, and 10, 
appear to be of the same species. 
3. A fig-like alcyonite, from Switzerland. In this fossil the pedicle, or organ of 
attachment, as well as its superior opening, is very evident. 
4. An alcyonite, from Wiltshire, bearing somewhat of the form of Alcyonium Ficus. 
5. A very perfect alcyonite, from the neighbourhood of Saumur, having four open- 
ings in its superior part, and the remains of several root-like processes. • 
6. A silicious alcyonite, beautifully marked, externally, with various risings and in- 
dentations. 
7. A polished transverse section of a silicified alcyonium, resembling the supposed 
petrified nutmeg of Volkmann and Scheuchzer. In this specimen the regular 
arrangement of the muscular fibres, or tubuli, is seen. 
8. A fig-formed alcyonite, of the same species with that which is imbedded in flint, 
Plate XI. Fig. 8. 
9. A calcedonic alcyonite, possessing a reticulated surface. 
10. A longitudinal section of the preceding fossil, shewing its internal structure. 
11. The external superior part, with the opening of a ficoidal alcyonite. 
12. A section of a ficoidal alcyonite, with fibres ramifying through its substance. 
13. The polished transverse section of the ficoidal alcyonite, Fig. 11, shewing in the 
centre appearances like the receptacles for the pips of fruits. 
14. A small calcareous spongite, or alcyonite, from Switzerland. 
15. The appearance yielded in consequence of subjecting a similar fossil to the action 
of diluted miiriatic acid. 
