SECTION IV., 1911. [3] TRANS. R. S. C. 
Presidential Address—The Past Vertebrate Life of Canada. 
By Lawrence M. Lampe, F.G.S., Vertebrate Palæontologist to the 
Geological Survey of Canada. 
(Read May 16, 1911). 
We are indebted to Palæontology for our knowledge, such as it is, 
of the past life of this earth, a knowledge which enables us to under- 
stand better the forms of life now with us, and though the palæontolo- 
gical record is discontinuous and broken by many gaps, yet, thanks 
to the efforts of the many, and the ever increasing number of zealous 
students in this particular field of investigation throughout the world, 
each year brings forth fresh discoveries by means of which some of 
the gaps are reduced and others are more or less completely bridged 
over. There are many problems to be solved in connection with the 
evolutionary changes from low to higher forms of life, but these can 
only add to the zest of original research, and the difficulties to be over- 
come should act as an incentive to further activities on the part of those 
engaged in attempting to unravel the mysteries of life. 
The first known form of vertebrate life in the northern half of 
this continent—in our Canada of to-day—is represented by the remains 
of a species of Heterostraci, the simplest of the Ostracoderms, those 
humble armoured organisms, which lived in shallow seas and were 
apparently lower in rank than the true fishes. These remains, consisting 
of sculptured plates, are from dark carbonaceous shales in the Nerepis 
hills of southern New Brunswick, and have been described under the 
name Diplaspis acadica, by Dr. G. F. Matthew who considers the beds 
to be of Clinton age. Regarding the Ostracodermi as the oldest forms 
of life which appear to have had a notochord, this species then con- 
stitutes our earliest record of vertebrate life. 
The next oldest species in point of time consists of a tooth of a true 
fish of the order Crossopterygii, viz., Dendrodus arisaigensis, Whiteaves 
of the upper Arisaig series, near Arisaig, Nova Scotia, considered to be 
of the horizon of the Lower Helderberg group. This species heralds 
the diverse forms of fishes found in the next succeeding geological 
division. 
From this remote period we shall pass by successive stages through 
the later formations, each with its distinctive fauna, with an ever 
increasing variety, from simple to more complex forms, to Pleistocene 
