145 
stance belonging to corals, but that it was formed of a substance, 
whose alcyonic texture is yet to be seen. This body, invested with 
its highly-coloured cortical substance, as the figure shews, being dis- 
posed in deeply indented folds, somewhat like the heraldic nebule» 
must have possessed, in an eminent degree, the pqwer of enlarging or 
diminishing the cavity which it formed, by extending, and straighten- 
ing, or contracting, and corrugating the line in which it was disposed. 
As has been seen in two or three other instances, the original colour of 
the animal, being here a reddish brown, has been preserved. 
But to return to the Maestricht fossil. — With respect to its stellu- 
lar columns, and connecting filaments, there can be no difficulty in' 
considering them as constituting a fossil whose form is the most sin- 
gular, and whose history is the most difficult to make out, of any 
which have come under our examination. Not only does it differ ma- 
terially from any known recent zoophyte, but even from any fossil 
which, in my knowledge, has been discovered in any other part of 
the world. 
In the fossil substance which comes next under our examination, 
insuperable difficulties will, I believe, oppose its arrangement under 
any existing genus. It is figured in Knorr’s elegant work. (Suppl. 
Tab. VI. Fig. 1.) This fossil has been considered by many as an in- 
crusted millepore ; by Mons. Guettard it has been supposed to be a 
coralline; and by Mr. Walch, who observes that it bears no marks, 
either externally or internally, of a coralline, it is believed to be an al- 
cyonium. After inspecting the specimen figured Plate XII. Fig. 13, 
with the utmost care and attention, I was^ unable to concur with any of 
the opinions which had been formed respecting this fossil. Upon exa- 
mining the largest and most distinct branch with lenses of different 
powers, I was obliged to consider tbe marks on its surface, as bear- 
ing no analogy with those peculiar to the surface of a millepore. In- 
stead of pores, a lens of considerable magnifying power enabled me 
to discover, that the surface was marked by minute tuberculaled lines 
VOL. IT. 
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