27 
polype. In the centre of this part of the specimen, the base of the root 
may be observed ; the root itself, with its surrounding processes, having 
been bowldered down nearly smooth. 
Plate IV. Fig. 1, represents a variety of this species, which has 
acquired more of a pyramidal form ; its body having been so elongated 
as to have terminated almost in a point, where the root has evidently 
been broken off. The remains of the root are, however, still observable, 
and are surrounded with several processes, the appearance of which 
sufficiently evince that their office was to assist in affixing the plant-like 
habitation of the animal to its destined spot. 
A circumstance which particularly claims observation in this species 
of madreporite, is, that of a second coral proceeding, in the manner of 
proliferous flowers, from the disk of the first. In the specimen, Plate IV. 
Fig. 3, a separation may be seen of about half the circumference and 
nearly of half the diameter of the coral. The commencement of a 
similar process is observable in several other specimens. The specimen. 
Fig. 5, has obviously obtained its increase in this manner, by the_ 
formation of fresh corals from the disks of the preceding. 
The size of these corals, as has been already observed, vary con- 
siderably: indeed, I suspect that I have seen some from Derbyshire, 
even upwards of a foot in length. Equally considerable also is the 
variety of forms which they assume. In some the shape is completely 
turbinated: in others the length is considerably protracted; some- 
times in a straight, and at other times in a curved direction, as at 
Plate IV. Fig. 8. The polished longitudinal section of this fossil 
shews the internal part of the madrepore to have been divided by 
transverse lamellae, which correspond with the circular projections on 
the surface. Such of these fossils as possess a curved form are fre- 
quently of a considerable size, sometimes nearly approaching even to 
the magnitude of a bullock’s horn. In a specimen from Perthshire, 
lately offered to me for examination, not only the form of the goaFs 
or ram’s horn, but the colour, and even somewhat of the disposition 
