PRESIDENTS ADDRESS. 347 
Brachiopods, three of sponges, and two of Foraminifera. Dr. 
Mathew points out that the Trilobites of this fauna can be 
distinguished from those of Cambrian by having continuous 
eye-lobes, and he says that the fauna as a whole is more primitive 
and more pelagic in character than the Olenellus fauna. 
Nevertheless, as the Olenel/ws fauna has not been found in the 
neighbourhood, he thinks it possible that the two might be con- 
temporaneous, and that the difference between them may be due 
to difference in geographical station. 
It appears, therefore, that out of the eight sub-kingdoms into 
which animals are divided by zoologists, six were represented in 
the pre-Cambrian times ; but until we come close up to the Cam- 
brian, the Protozoa and Porifera alone show much diversity, and 
they were certainly the dominant feature of the animal life of the 
early seas. No recognisable vegetable remains have been found 
in any pre-Cambrian rock, but pelagic alge must have existed, 
for otherwise there would have been no food for the animals. 
CAMBRIAN LIFE. 
When we pass upward into the Cambrian period we find that 
life has made considerable progress, including the appearance of a 
new sub-kingdom—the Echinodermata ; and in the Upper Cam- 
brian we have the first Bryozoa and Pelecypoda. However, the 
only fossils which show much variety are the Brachiopoda and the 
Trilobites. 
The Hydrozoa were represented by Sertularians, Graptolites, 
and Medusz, the latter being so abundant that the National 
Museum at Washington has more than 8,000 specimens. These 
Cambrian Medusz belong to a distinct family of the Discomedusze 
called Brooksellide, and are distinguished by having a lobate 
umbrella without any marginal tentacles. It is remarkable that 
such soft things as jelly-fish should have been preserved as fossils ; 
but although they have no hard parts, their tissues, when saturated 
with water, are sufficiently firm to make impressions on the mud 
or sand on which they have been thrown by the waves, and when 
the umbrella is turned upside down the gastric cavities get filled 
with the mud or sand and leave star-like marks, which are easily 
recognised. The Actinozoa are represented only by the curious 
Archceocyathine, which appear to be related to the perforate corals. 
The hingeless Brachiopods were the first of their class to appear. 
According to Beecher, Paterina of the Lower Cambrian approaches 
nearest to the primitive stock, for it closely resembles the embry- 
onic shell of later forms ; and during the Cambrian period it gave 
rise to at least five different types of Inarticulata, one of which— 
represented probably by Autorgina—led up to the Articulata, the 
first known of which, Orthis, had become well established in the 
Upper Cambrian. 
