308 GEOLOGICAL EVIDENCES 
beds; but we have not yet succeeded in detecting among them 
a single dicotyledonous tree of the higher sub-classes, and only 
a few dicotyledonous leaves. ‘They are all coniferous gymno- 
sperme, chiefly of the pine and araucarian families; and in 
the Fauna associated with them, we find that the prevailing 
forms are reptilian. The reptile occupied as large a place in 
these Secondary periods as that occupied by the mammal in 
the Tertiary ones. So far, indeed, as we yet definitely know, 
there existed during these herpetological ages only two species 
of mammals, —a small marsupial and small insectivorous ani- 
mal. Again, in the Flora of the Paleozoic division, we still 
find the pine and the araucarian, mixed, however, with extra- 
ordinary vegetable types, some of which have become wholly 
obsolete, and some of which are linked by but faint analogies 
to aught that now exists; but which, generally speaking, seem 
to be, though high representatives of their kind, of a kind in 
itself not high. In the Fauna of the period, down till at least 
the base of the middle Paleozoic system, fishes seem the dom- 
inant forms, — fishes, many of them of great size, formidably 
armed, and uniting in their organization, reptilian to the ordi- 
nary ichthyic peculiarities, but in not a few of their number 
destitute of an internal skeleton of bone. True, during these 
ages the reptile also existed, but in such scanty proportions, 
that while the Coal Measures have yielded their ichthyie re- 
mains by thousands and tens of thousands, they have yielded 
to the sedulous search of the geologist only three reptiles and 
the trace of a fourth; and, while in single platforms of the 
Old Red Sandstone there are perhaps as many fishes entombed 
as are at present living on all the fishing banks of the country, 
the entire system has furnished the remains of but one reptile 
(if, indeed, the lacertian of Spynie in reality belong to it), and 
the foot-tracks of a few others. In the Lower Paleozoic forma- 
tions, the trace of even the fish becomes untrequent, and the 
