p. 1

Cyathophylloide

Genus Polydilasma, Hall,
Pal. of N.Y. Vol 2 p. 112. (1852)
Am. Jour. Sc. 2d Ser. Vol II p. 399.

Corallum turbinate;
lamellae numerous, thin, apparently
rising in pairs, and one often much stronger than the other; cell broad, margin
thick and strong, with a deep
central pit; half the lamellae reaching
to the centre of the cell, where they are
complicated or contorted; transverse
septa below the central part of the
cup obsolete or irregular. --Allied
to Calophyllum, but does not show
the transverse septa characteristic
of that genus. The cell is very peculiar
in its character, one half only of the rays extending
into the deeper portion, giving it a peculiar
aspect which is preserved in solid chrystaline
specimens, even when no rays are visible or when
they are very indistinct.

Gr. polus, many, dis, double & elasma, lamella.