DESCRIPTION OF CORALS. 149 
The form, size and general characters of the Bracklesham specimen are given 
in Tab. IX. fig. 25. It consisted apparently of half a small irregular, ovoid 
mass. On the fractured or opposite side, closely aggregated columns radiated 
from a semicylindrical groove or intersected tube, not quite a line in diameter, 
and traversed the specimen completely in a curved direction. Part of another 
cylindrical cavity, but with a transverse range, was also noticed. The wall of 
the groove was a thin, nearly smooth layer, which totally concealed the lower 
terminations of the polype-columns, A French specimen exhibited similar, irre- 
gular or branched cavities with one enlarged end ; the whole being lined, so far 
as could be ascertained, with a detachable, very calcareous layer, about one-fourth 
of a line thick, and composed of irregular cells with circular openings. (Cor- 
tical portion of a Plexaura ?) 
The columns, as exhibited in the fractured surface, diverged from the groove 
in all directions, but not to a uniform extent, the thickness in one part being 
half an inch, while in the opposite portion it did not exceed a quarter. The 
columns were so intersected that it was difficult to trace their outline or range 
satisfactorily, but they appeared, where the thickness was greatest, to extend 
continuously from the groove to the outer surface ; and the walls were through- 
out in close contact, except at the angles, where the downward course of the 
conical projections was visible. In some conditions of growth more or less of 
interspace, however, probably existed between the sides of the stars*. (Con- 
sult M. Michelin’s figure 6 a, pl. 44, op. cit.) 
The number of sides in stars of greatest area was generally six, but sometimes 
seven, and in those of less dimensions it varied from three to six. The dia- 
meter of the largest star was about 1 line. 
The true, broad lamellz were chiefly limited to eight, but nine and ten were 
noticed at the bottom of one or two terminal cups: very narrow or unequal 
in Sideropora of De Blainville, and Styl. pistillaris, Schw., is considered as probably a variety of 
Sideropora elongata, De Bl.(p.517). No allusion to the fossil species of Schweigger (Styl. monti 
cularia) has been observed in Mr. Dana’s important work; and it is believed that the tertiary fossils 
referred to Stylophora possess many essential differences from the recent corals which form the genus 
Sideropora. Should paleontologists think otherwise, it should still be remembered that Schweigger’s 
name (Beobachtungen, &c. 1819) has a prior claim to that of M. de Blainville (Man. d’Actinol. 1830 
-1834). 
* M. Lamarck considered this fossil to have contiguous stars, but M. De France regarded the stars 
as separated, on account of the lamelle in those immediately adjacent not biending (Dict. Se. Nat. 
t. xlii. p. 386). 
x 
