152 DESCRIPTION OF CORALS. 
vesicle within the cell, deeply seated ; lower parietal lamina thin, slightly con- 
cave, nearly on level with mouth of cell; surface sometimes provided with a 
minute tubercle near distal edge. 
The marked peculiarity of this coral is the hollow cylindrical pedicle, which 
was detected in every case of a perfect edge (fig. 106). About twenty-five speci- 
mens belonging to Mr. Dixon and Mr. Edwards’s cabinets were examined. ‘The 
diameter of the largest was 3 lines, and of the smallest 1 line. The shape 
was generally circular, and the surface flat, but sometimes slightly contorted. 
The pedicle was easily detected on the edge of the disc by its distinct circular 
wall, and deep, regular hollow, also by its occupying the whole thickness of the 
coral; and it was readily recognized at the margin of the disc as well as for a 
more or less limited range towards the centre by its relatively coarse, reticulated 
structure (fig. 10a). It was probably the first-formed portion of the polypidom, 
and progressively extended as the disc expanded. In the specimen only 1 line 
in diameter, it was as distinct as in that which had three times the linear dimen- 
sions ; and in some instances an irregularity or a fine furrow could be traced 
from the exposed portion of the pedicle nearly to the centre of the specimen, 
while in others the footstalk was clearly overlaid in part by celis near the margin 
of the coral. 
No clear case was detected of more than two opposite rows, and the position 
of the cells conformed to the outline of those next adjacent, whether in the same 
layer or in the opposite, having no interspaces. So far as observation extended, 
the walls of contiguous cells were not separable. The mouths near the circum- 
ference of the disc had sharp, fine margins, but in the central area of some 
specimens they were often thickened, and occasionally the apertures were closed, 
the general surface presenting an irregular, confused structure. From this cir- 
cumstance the layers probably never exceeded two*. 
The supposed gemmuliferous vesicles or chambers gave the cells to which 
they appertained a semiglobular projecting surface (fig. 10a, near X). In their 
* In some respects the Bracklesham coral resembles the Orbitolites macropora of Lamarck, as 
figured by Goldfuss (Petref. pl. 12. fig. 8), and stated by De France to occur at Maestricht, but by 
Goldfuss in the sandy beds of the caleaire grossier near Grignon. The fossil under consideration is 
most manifestly not an Orbitolites, nor is there any sufficient structural agreement to warrant the 
supposition that the two fossils are generically identical, whatever may be the true nature of the coral 
figured in the ‘ Petrefacten.’ 
(The generic assignment of the Bracklesham coral must also be considered provisional.—Note, 1848.) 
