By this same method of research, the more ancient strata 

 of the earth have been explored, and, in our Western wilds, 

 veritable battle-fields, strown with the fossil skeletons of the 

 slain, and guarded faithfully by savage superstition, have been 

 despoiled, yielding to science treasures more rare than bronze 

 or gold. Without such spoils, from many fields, I could not 

 have chosen the present theme for my address to-night. 



According to present knowledge, no vertebrate life is known 

 to have existed on this continent in the Archaean, Cambrian, or 

 Silurian periods; yet during this time, more than half of the 

 thickness of American stratified rocks was deposited. It by 

 no means follows that vertebrate animals of some kind did not 

 exist here in those remote ages. Fishes are known from the 

 Upper Silurian of Europe, and there is every probability that 

 they will yet be discovered in our strata of the same age, if not 

 at a still lower horizon. 



In the shore deposits of the early Devonian sea, known as 

 the Schoharie Grit, characteristic remains of Fishes were pre- 

 served, and in the deeper sea that followed, in which the 

 Corniferous limestone was laid down, this class was well 

 represented. During the remainder of the Devonian, Fishes 

 continue abundant in the shallower seas, and, so far as now 

 known, were the only type of vertebrate life. These fishes 

 were mainly Ganoids, a group, represented in our present 

 waters by the Gar-pike (Lepidosleus) and Sturgeon (Acipenser), 

 but, in the Devonian sea, chiefly by the Placoderms, the exact 

 affinities of which are somewhat in doubt. With these were 

 Elasmobranchs, or the Shark tribe, and among them a few 

 Chimaeroids, a peculiar type, of which one or two members still 

 survive. The Placoderms were the monarchs of the ocean. All 

 were well protected by a massive coat of armor, and some of 

 them attained huge dimensions. The American Devonian fishes 

 now known are not as numerous as those of Europe, but they 

 were larger in size, and mostly inhabitants of the open sea. 

 Some twenty genera and forty species have been described. 



