351 
ON THE OLDEST KNOWN EOSSIL^ ETC. 
may remain fossilized when the present geographical con- 
ditions shall have been altered^ when the sea-bed has risen 
up with its accumulated coral-reefs and shell-banks; and, 
possibly, they may form a distinctive feature in the Geology 
of the future, remaining distinguishable as organic remains 
when shell and coral, mud and sand, shall have been squeezed 
and modified as obscure elements in the mazy entanglements 
of Metamorphic rocks ! So the Eozoal limestones may be 
the only well-marked persistent organic witnesses of an old 
deep ■ ocean, rich with life ; whilst the inhabitants of the 
shallows, though of higher grades in life, have long since lost 
their individuality in the graphites, phosphates, silicates, and 
sulphides of the crystalline rocks. 
Eozoon has its existing representatives as to its wild and 
accumulated growth, though not to such an extreme, in some 
well-known Foraminifers, by no means the lowest of their 
class ; and in its shell- structure (which, as Dr. Carpenter well 
argues, is an essential character), its best representative is the 
highest of Foraminifers — Nummulina. Had it been found in 
existing seas, it would have been classed by Carpenter as a 
free-growing form of that genus. If, then, the lowest of the 
low are expected to be the first among the first, other and 
lower forms, such as Miliolina and Orhitolites, are yet to be 
found in the earliest rocks. This reminds us that a Silurian 
(and, therefore, later) fossil, known as Receptaculites, is made 
up on the plan of Orhitolites (as remarked by Carpenter), and 
that Stromatoporaj Archceocyathus, and other obscure Silurian 
fossils (as Dawson has suggested), may have to be classed as 
Foraminifers of large size compared with existing forms, but 
not strange as to their structure. 
Not only in Canada, but in Connemara is Eozoon found; 
and, doubtlessly, other serpentinous marbles may yield it, if 
looked for. The Laurentian formation is known to exist in 
Canada, North and South America, Norway, West Scotland 
and the Hebrides, Wales and Malvern, France, Bavaria, and 
Bohemia. In Leicestershire, Eastern Scotland, Ireland, India, 
and other places, many granites, serpentines, and associated 
schists will probably come out as Laurentian ; at all events 
geologists have directed their attention to the matter, and 
cautious research will make all clear in time. 
[Logan^s Keports on the Geology of Canada; Bigsby^s 
Memoir on the Laurentian rocks in the Geological Magazine ; 
and especially Logan, Dawson, Carpenter, and HunCs Memoirs 
on Eozoon in the Geol. Soc. Quart. Journ. must be referred to 
by those interested in this old and curious fossil.] 
