405 
the wood — that they are not coralline bodies — that they are not 
stalks of pentacrinites— and that the surrounding ring has not, in 
every case, been derived from the same origin as the contained 
column. Thus much, I trust, may be asserted, with respect to what 
these bodies are not ; but as to any opinions, as to what they really 
may have been, these have been formed under such doubts, as to 
require that I should offer them with hesitation. There appears to 
be every reason to conclude, with Mr. Walch and others, that this 
columnar body was originally a zoophyte, totally different from any 
which are now known to exist ; and in very few respects, indeed, 
analogous with any of those which we see in a fossil state. It also 
appears, that one of the habitudes of this insect was that of forming 
a tube, for its domicile, in any appropriate substance ; and that 
decayed wood was most frequently, if not always, selected by it for 
this purpose. 
No section or specimen, which I have yet seen, allows us to 
determine whether the complete animal was in one continuous 
straight columnar body, or whether it separated into ramifications': 
nor can it be ascertained, by any specimens I have examined, what 
is the natural termination of the ends of this substance ; no change 
of its columnar form having been yet seen, which would authorize 
the suspicion of its divaricating, and forming a head in the manner 
of the encrinus. 
Plate VII. Fig. 1, represents a specimen which gives a very 
favourable view of the general appearance which this stone yields : 
it is not, however, so rich in colour, as some specimens are. On 
the lowe’r edge very plain traces of its ligneous origin may be per- 
ceived, and towards the other edge may be seen several of the stel- 
lated bodies in the tubules, to which some are attached at one side, 
whilst others are exactly in the centre ; the other part of the tubule 
being in some entirely empty, and in others either partly or com- 
pletely filled by silicious crystals. 
