32 
Plate IV. Fig. 16, is the representation of an elegant corallite, from 
the chalk-pits, at Northfleet, in Kent, attached to the chalk in which 
it was found imbedded. Its root, which is adherent to a plate of echinus, 
is regularly indented with angular excavations, which appear to be about 
eight in number. From the root proceeds the body of the coral, gently 
bending and gradually enlarging into a conical form, about an inch in 
length. Its under and external surface is elegantly striated with distinct 
ridges, regularly disposed in the following order: midway between 
every two of the largest ridges is placed one rather smaller. The 
star on the disk faj is formed by perpendicular lamellae, reaching from 
each of the largest ridges on the circumference, to the centre, and by 
smaller lamellae proceeding from each of the ridges of those of a smaller 
size, but which reach a very little way towards the centre. As 
there are no transverse ridges on the external surface, so there are no 
horizontal plates observed internally, at least as low as the eye can com- 
mand, which is very near to the bottom. 
The specimen, Plate IV. Fig. 15, is also from the chalk-pits, at North- 
fleet. In this delicate specimen, the pedicle is very observable; the 
ridges, on the external surface, are all nearly similar in size, and disposed 
with much regularity and neatness. The stellated disk (h) is formed by 
perpendicular plates, answering to each of these ridges, and nearly 
meeting in the centre. 
The raadreporite, Plate IV. Fig. 9j which I have reason to believe to be 
an Italian fossil, is in the form a flattened cone : at the point of the cone 
appears to have been a pedicle, from which proceed innumerable striae 
which terminate in the other end of the cone : where a star is formed, 
which differs materially in its form from any which have existed in the 
specimens hitherto mentioned. From the inner sides of the cone proceed 
perpendicular plates which meet, not in a point in the centre, but in a 
line, possessing about three-fourths of the centre of the longest diameter 
of the base of the cone. 
