ORYCTOLOGY. 
explained; since they possess (especially 
the roots of trees) that degree of solidity 
which appears to be favourable to the pro- 
cess of petrifaction. From tlie want of this 
necessary properly it undoubtedly is, that 
we possess so few remains of tender flower 
leaves, and none of pulpy fruits. 
From the same cause, the great prone- 
ness to decomposition, the number of ani- 
mal fossils is considerably limited : those 
substances being only preserved in a mine- 
ralized state which originally possessed a 
considerable degree of solidity; such are 
the bones, teeth, horns, shells, scales, &c. 
Tlie animal, however, far exceeds the vege- 
table kingdom in the number and variety of 
fossils which it yields, as well as in the dis- 
tinctness of form, and excellency of preser- 
vation, in which they are found. 
Adopting in a great measure the arrange- 
ment of Waller, we shall commence our exa- 
mination of the animal fossils with those 
which have derived their origin from corals. 
These fossils are, of course, merely the re- 
mains of the dwellings which have been 
formed by the various coral insects, and 
which are so frequently found in the cabinets 
of the curious; 
Immediately On commencing this exami- 
nation, we are struck with a similar want of 
agreement between the recent and fossil 
corals, with that which has been noticed 
between recent and fossil vegetables. Of 
the genus Tubipora it does not appear, at 
least by the observations made in Mr. Par- 
kinson’s second volume 'of ‘‘ The Organic 
Keniains of a former World," that a single 
species which is known recent has been 
found as a fossil. Several fossil species are, 
however, described, of which nothing similar 
is known in a recent state. The most 
striking of these is the Tubipora cateqularia, 
or cliaiu coral, the surface of which, in con- 
sequence of the tubes being in contact at 
their sides, has frequently a very curious 
reticulated or catemilated appearance. 
Plate I, fig. 4, represents this fossil in its 
usual state : and at fig. 5 is shewn the ap- 
pearance yielded by a transverse section. 
Tubipora fascicularis, T. stellata, T. repens, 
and T. stnies, which have been described 
by dilferent authors, and which are unlike 
to any known recent Tnbipore, give reason 
for supposing that the number of species of 
fossil Tubipores exceeds that of the recent 
species. 
The fossil Madrepores are not less rich in 
variety, nor less comparatively numerous, 
than the fossils of the preceding genus. The 
forms of several species of the fossil Madre- 
pores do frequently approach to those of 
the different recent species ; but in a con- 
siderable number of the fossil Madrepores no 
resemblance is discoverable, except in their 
stelliform openings, with any recent coral. 
So great indeed is this departure in some 
instances from the general characters of 
our present known Madrepores, that it has 
been deemed difficult to determine, whether 
some fossil specimens should be considered 
as Madrepores or as Alcyonia, It is im- 
possible, without the aid of numerous 
figures, to give satisfactory notions of the 
forms of the several fossil Madrepores which 
have been hitherto discovered ; the most 
interesting only will therefore be here par- 
ticularized. 
The Madrepores consisting of a single 
star appear to be much more numerous in 
a mineral than in a recent state. These 
are either of a discoidal fotm, having a con- 
cave superior and a convex inferior sur- 
face; of a pyramidal top-like form, termi- 
nating in a pedicle ; or of a lengthened py- 
ramidal form, bearing in some, from a slight 
curvature, the appearance of the horn of an 
animal ; whilst others are cylindrical for a 
considerable part of their length. 
The first of these, Madrepora porpita, 
the shirt-button Madrepore, has been long 
known to the collectors of fossils in this 
kingdom. Dr.Woodward describes several of 
them, as mycetitae discoides. The second spe- 
cies (Madrepora turbinata) is also frequently 
found in different parts of Great Britain, as 
well as in Sweden, Norway, and in several 
parts of France, Switzerland, and Italy. 
These latter fossils have been termed' by 
Dr. Woodward mycetitas conoides seu ca- 
lyciformes. When they have acquired some- 
what of 'a hornlike shape, they have been 
distinguished by the term ceratites ; and 
when they have possessed more of the cy- 
lindrical form, they have been termed colu- 
melli lapidei et hippurit® ; and from a sup- 
posed resemblance, tliey have been also 
considered as the petrified roots of briony. 
Some of the single starred corals are found 
united at their pedicle, and approaching 
towards eacli other at their summits, though 
disjoined nearly through their whole length. 
Tliese, from their resemblance to petrified 
reeds, have been named junci lapidei. 
It would be useless to attempt, in this 
sketch, to specify the considerable variety 
of fossil Madrepores formed of aggregated 
circular stars, and which have been desig- 
nated as astroites, &c. Those which are 
composed of angulated stare are, perhaps, 
not so numerous : many of these, however, 
