846 PALEONTOLOGY AND EVOLUTION xi 



extensive and diversified than that of the Trias, 

 while its chief types, so far as osteology enables 

 us to judge, are quite as highly organised. Thus 

 it is certain that a comparatively highly organised 

 vertebrate type, such as that of the Labyiintho- 

 donts, is capable of persisting, with no considerable 

 change, through the period represented by the 

 vast deposits which constitute the Carboniferous, 

 the Permian, and the Triassic formations. 



The very remarkable results which have been 

 brought to light by the sounding and dredging 

 operations, which have been carried on with such 

 remarkable success by the expeditions sent out by 

 our own, the American, and the Swedish Govern- 

 ments, under the supervision of able naturalists, 

 have a bearing in the same direction. These in- 

 vestigations have demonstrated the existence, at 

 great depths in the ocean, of living animals in 

 some cases identical with, in others very similar 

 to, those which are found fossilised in the white 

 chalk. The G-loligcrince, Cyatholiths, Cocco- 

 spheres, Discoliths in the one are absolutely 

 identical with those in the other ; there are 

 identical, or closely analogous, species of Sponges, 

 Echinoderms, and Brachiopods. Off the coast of 

 Portugal, there now lives a species of Bcryx, which, 

 doubtless, leaves its bones and scales here and 

 there in the Atlantic ooze, as its predecessor left 

 its spoils in the mud of the sea of the Cretaceous 

 epoch. 



