DESCRIPTION OF CORALS. 145 
duced from the characters of limited portions, and not from an investigation of 
the whole surfaces. 
The finest specimen is represented in Tab. I. fig. 6, of the natural size. It 
was partially compressed, but had evidently been produced around a perishable 
cylindrical body. Schweigger’s figures exhibit a similar contour, with a central 
cavity, and he notices likewise the indications of an encrusting growth; M. De 
France also alludes to the latter characters, but he states that the fossil assumes 
various forms (Dict. Sc. Nat. t. xlil. p. 385), a necessary consequent in a para- 
sitic zoophyte. The thickness of the coral layer at the lower extremity of the 
specimen did not exceed 14 line, and at the upper it was barely 1 line; another 
specimen in Mr. Edwards’s cabinet, | inch 2 lines in length and 5 lines in dia- 
meter, had a layer nearly 2 lines thick ; and Schweigger’s specimens had also a 
thin polype-crust. 
The stars in the Bracklesham specimens rarely if ever exceeded a line in the 
greatest width, and they were often much less; their form also was seldom 
regular, having evidently been subjected to considerable interference during 
growth ; and the general surface exhibited, as a result apparently of such inter- 
vention, a confused aggregate of small polygonal cavities, surmounted by conical 
projections. The more regular, mature stars had nearly straight sides, as cor- 
rectly given in M. Michelin’s magnified figure (Iconog. pl. 45. fig. 1 6), and not 
a rounded outline as exhibited by Schweigger (Beob. taf. 6. fig. 62 d) ; never- 
theless, instances occurred in which the sides were curved and the angles ill- 
defined. The lamellz, which issued directly from the inner surface of the walls, 
were so often broken, that it was difficult to ascertain their full number; but 
they never exceeded twelve, and not a trace was detected of intermediate, rudi- 
mentary plates. M. De France, in his account of Ast. hystrix, gives the number 
as 6-8 (Dict. Sc. Nat. t. xli. p. 385), and M. Michelin as 6-12 (Iconog. p. 160). 
The perfect lamella at the junction with the walls were relatively thick, the 
interspaces being arched, but they became thinner as they ranged towards the 
centre, and were occasionally waved. In the lower part they were united to the 
axis, though free in the upper. This character was clearly shown in a fracture 
transverse to the cylinder, or through the polype-layer. The horizontal dia- 
phragms between the lamelle were relatively thick, but irregular in position and 
number, so far as their nature could be ascertained; and they probably had 
extended half-way up the stellular cavity. The axis was rarely visible, and even 
when exposed in a perfect state it did not verify Schweigger’s fig. 62 d, nor sup- 
