4 THE ROYAL SOCIETY OF CANADA 
times in which the majority of the species are either closely allied to or 
identical with those now living, and it is my purpose in this address 
to review in as brief a manner as possible, the different faunistic groups 
in order, touching lightly the salient points of each. 
The above two forms give us but a glimpse of Silurian life, so far 
as vertebrates are concerned. At this period the invertebrates pre- 
ponderated and the dawn of vertebrate life had but just begun. At 
present we can speak only of those forms of which we have reliable 
data but in time we shall no doubt be able to add much to our present 
very limited knowledge of the vertebrates of Predevonian times. 
Leaving the Silurian with its paucity of known species, we find in 
the Lower Devonian Ostracoderms of a higher type, belonging to the 
order Osteostraci. The species are of the genus Cephalaspis and have 
been described by Lankester, Whiteaves and Traquaiz, from the northern 
shore of Gaspé bay and from Campbellton, N.B. With these primitive 
forms occur also a varied fauna of fishes, viz., Elasmobranchs, Chimæ- 
roids, Dipnoans and a Teleostome. The Elasmobranchs belong to the 
orders Pleuracanthidæ, Diplacanthidæ and Acanthodidæ and have 
been found in the beds at Campbellton which have also yielded remains 
of the Dipnoan fish Phlyctenaspis acadica (Whiteaves) considered by 
Smith Woodward to have been a forerunner of the highly specialized 
Arthrodira. Farther west, in Ontario, in the Corniferous formation, 
certain fish spines occur, some of which are generally supposed to be 
referable to the Chimeroidei. The Crossopterygian Telostome, Ony- 
chodus sigmoides, Newberry is also found in the Corniferous of Ontario. 
In the Upper Devonian we find the last of the early Ostracoderms 
of the order Osteostraci represented by Cephalaspis laticeps of Traquair 
from the world renowned Scaumenac beds at the western end of Chaleur 
bay in the province of Quebec. Here also occurs Euphanerops repre- 
senting a family of the same order as the above, and noteworthy as 
being the only Ostracoderm revealing traces of the spinal column. 
Characteristic of the Upper Devonian at this locality and related to 
Pterichthys is Bothriolepis canadensis, Whiteaves belonging to the 
Antiarchi, the highest order of the Ostracoderms, and remarkable for 
its complex dermal skeleton and the length of its pectoral appendages. 
We are indebted principally to Whiteaves, Traquair, Smith Woodward 
and Patten for our knowledge of this interesting species, the beautifully 
preserved specimens of which, from the Scaumenac beds, have attracted 
collectors from far and wide during recent years. At this time also 
we find a very rich fauna of the true fishes, Acanthodians, Chimæroid.., 
Sirenoids, Arthrodires, and Crossopterygian and Actinopterygian 
Teleostones. The Scaumenac beds supply representatives of all these 
ordinal groups with the exception of the Chimeroids which are found 
