A monograph of the British fossil corals - kreidefossilien.de

INTRODUCTION.
li
the sclerenchyma, which, instead of forming imperforated lamella as in the preceding
groups, is always porous, or even reticulate. In general the mural apparatus constitutes
here the greatest part of the corallum, and does not consist of costal laminae ; the walls
are always perforated, and completely or nearly completely naked. It is also to be
remarked, that the visceral chamber is almost completely open from top to bottom, and
never filled up with dissepiments or synapticulae, as in most of the Zoantharia aporosa, or
with tabulte, as will be seen in the next two sections of this order.
The perforated Zoantharia form three natm-al families : Eupsammidse, Madreporidse,
and Poritidse.
Family V.
EUPSAMMIDtE.
Milne Edw. and J. Haime, Ann. des Sc. Nat., 3"' serie, vol. x, p. (j5, 1848.
Corallum simple or complex, with well-developed lamellar septa, a spongiose columella,
and perforated, granular, subcostulated walls.
The septa are always numerous, and those of the last cyclum are never situated in the
direction of a line drawn from the centre of the calice to its circumference, but are bent
towards those of the penultimate cyclum, so as to produce the appearance of a six- or
twelve-branched star. The interseptal loculi are completely open from top to bottom, or
divided only by a few incomplete trabiculge. The walls have a granulate vermiculate surface,
and become often very thick in advanced age, but never constitute a loose spongy mass,
as in Madreporidse and Poritidac, or a compact ccenenchyma, as in Oculinidse.
The star-like arrangement of the septa, which is visible in transverse sections of these
corallums, as well as in the calice, is not met with in any other family. The principal
septa are sometimes imperforate, but those of the succeeding cycla are more or less porous.
It is also to be noted that there are never any pali, and that the costae are always rudimentary
; sometimes there is a rudimentary epitheca.
I. Genus Eupsammia.
Milne Edw. and J. Haime, Ann. Sc. Nat., 3""" serie, vol. .x, p. "7, 1848.
Corallum simple, subtm-binate, free, and not presenting any lateral mural expansions.
Calice oval and rather deep. Se'pta broad, slightly exsert, granulate, closely set, and
forming four or five cycla. Costa simple, distinct from the basis of the corallum, nearly
equal, slightly vermiculate, and composed of a series of distinct,
projecting granulse.
Typ. sp., Eupsammia trochiformis, Milne Edw. and J. Haime, loc. cit., tab. i, fig. 3 ; Madrepora trochiformis,
Pallas ; Turbinolia elUptica, Brongniart.