51 
the making out of such specific peculiarities as the reticulated surface of 
the sides of the stars. 
Madrepora Jlexuosa is composed of striated, cylindrical, ramifying 
tubes, bending inwards, and then uniting : the stars being concave with 
lainellee of similar lengths. In Ellis and Solander’s Natural History of 
Zoophytes, Plate XXXI. Fig. 5 and 6, is a very correct figure of the 
recent coral, which very much resembles a beautiful fossil specimen, 
apparently of this species of coral obtained from Sweden. It is im- 
bedded in a blue indurated marl ; which, although possessing a consi- 
derable degree of hardness, has been partly removed by a careful em- 
ployment of some instrument ; by which the characteristic form and 
surface of the coral is fully displayed. The terminations, as has been 
already observed is frequently the case with the fossil corals, are not 
preserved. The coral is, however, thoroughly impregnated with a spathose 
substance, which on being polished shews the agreement of the stars 
with those of the recent coral, in being formed of lamellse all of similar 
lengths, reaching from the circumference to the centre. 
A fossil coral is frequently found in pretty large nodules, in St. Vincent’s 
rock, near Bristol, a small specimen of which is depicted, Plate VI. 
Fig. 8, whose general external form approaches very nearly to that 
of the madrepora Jlexuosa. Its branches, like those of the m. jlexuosa, 
are cylindrical, rough, and striated; but its stars, instead of being 
concave, are of a subglobose form : instead of being composed of radii 
of equal lengths, they are formed by a certain number of rays, which 
pass from the circumference to the centre, and by a similar number 
interposed between the former, and which are so short as not to reach 
above a fourth part of the length of the former. The number of these 
rays varies from twelve to upwards of thirty of each series, according 
to the size of the coral. These rays are intersected by perpendicular 
concentric circular lamellae, which vary in number from two to six and 
more, according to the growth of the coral. A red ferruginous bole 
not only adheres to and deeply colours the external parts of these 
