A monograph of the British fossil corals - kreidefossilien.de

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CORALS FROM THE LOWER GREENSAND. 71
so as to constitute by their union a series of complete tabulae, subdivided by the primary
septa, and distant from each other about one fifth of a line. Exothecal dissepiments much
resembling the preceding ones. Diameter of the calices, and depth of the fossula, about
one line and a fourth.
Fossil from the lower greensand at Redhill cutting, Atherfield, in the Isle of AVight,
and at Peasemarsh.
The specimens here described belong to the Museum of the Geological Society, and had
been named by Mr. Lonsdale. The propriety of establishing a new generical division for
this remarkable coral, was very judiciously pointed out by that indefatigable palaeontologist
but, guided by reasons which we do not quite understand, he refers, with a sign of doubt,
this same species to the Cyaihophora of
M. Michelin, a genus which, in our opinion, does
not differ from true Stylina. The genus Holoci/stis differs from om- genus Stauria by its
extra calicular gemmation, and its costulated walls. It is the most modern representative'
of the great division of Zoantharia rugosa, which becomes predominant in the Palseozoic
formations, and is principally characterised by the tendency to a quadrate arrangement of
the constituti\'e parts of the CoralUtcs, whereas in the other sections of Zoantharia, six is
the fundamental number of the radiate organs.