EGBERTS — UPPER SILURIAN CORALS. 
55 
UPPER SILURIAN CORALS. 
A SKETCH BT 
GEORGE 0. ROBERTS. 
Coral-hunting in the dehris of a Wenlock-shale quarry ranks high — 
to my thinking — amongst the pleasures of geology. And, indeed, 
has no insignificant place among its wonders. For to any one not 
conversant with zoophytic life, it is hard to believe that the rugged 
corals that lie strewn about the quarry, once held sensitive masses of 
life — that from every pore tiny arms waved to and fro in the water 
to entangle the lesser creatures they lived on ; and that the animal — 
that slight thread of jelly-like substance, filling each tube, was at 
once a limb of the body and an independent creature, contributing, 
while attached, to the general support, and being able, if severed 
from the mass, to lead a separate existence and be itself the parent 
of others. The Wenlock series of the Upper Silurians have been 
rightly regarded as the metropolis of its zoophytic life, for both in 
variety and number, corals culminated in the seas of that age. Of 
these species, " so far removed from existing ones as to be quite 
unknown in modem seas, all, with rare exceptions, dying out at the 
close of the Palaaozoic epoch."* I will essay a famiUar sketch. 
I adopt the nomenclature of M. Milne Edwards, whose valuable 
memoir of Silurian corals, published by the Palaeontographical So- 
ciety, is my guide and instructor. 
True corals are called by zoologists Zoantharia ; and those with 
which we have now specially to do belong to the order Anthozoa. 
They have again been divided into cup-, and star-corals — Zoantharia 
rugosa, and millepores — Z. tabulata. The first division may either be 
simple — tenanted by a single polyp, or compound — the result of an 
aggregation of polyps, the latter, as its name implies, must always be 
the shelter and defence for a community. The animal itself was a 
* " Siluria," 3rd edition. 
