100 PEOF. J. LOGAN LOBLEY, F.G.S., F.R.G.S., ON 



Echinodermata, Cystoidea and Blastoidea ceased to exist and 

 Echinoidea greatly increased. In the highest Class of the 

 Moliusca, the Cephalopoda, many genera that are conspicuous in 

 the Palaeozoic rocks, as Cyrtoceras, Gomphoceras, etc., although 

 tetrabranchs, are not to be found in Secondary rocks, while 

 Ammonites, and the dibranchiate Belemnites, of which there 

 is no trace in the older rocks, are most conspicuous, both by 

 their abundance and specific development, in Secondary forma- 

 tions, and again are absent in more recent deposits and at the 

 present day. 



The dying out of species and genera of Gasteropoda, 

 Lamellibranchiata and Brachiopoda, and their replacement by 

 •others between the Lower Silurian period and the Quaternary, 

 are too numerous to be here enumerated. 



And if the great picture of the biological aspects presented 

 by this planet during geological time is strikingly vivified in its 

 upper part by the crowds of Vertebra ta, both terrestrial and 

 marine, that are absent from the stiller world of early Palaeozoic 

 times, so is it abundantly enriched by the higher forms of 

 jjlants that clothe the plains, the hilly uplands and the moun- 

 tain slopes. In the Carboniferous period of the Palaeozoic 

 epoch, it is true, an abundant flora covered low-lying plains, 

 but all the plants were cryptogams or gymnosperms. Magni- 

 ficent ferns, equisetums and lycopods, grew thickly and rapidly 

 where humid and warm conditions prevailed, but there were no 

 trees such as those that form the forests of the temperate zone 

 of to-day, or otfer food to man on their fruit-laden branches, nor 

 were there such flower-bearing shrubs as those that now 

 beautify both cultivated and uncultivated lands. These, the 

 higher forms of the Vegetable Kingdom, were reserved to make 

 their appearance in Cretaceous times, and to develop in 

 Tertiary times until in the Miocene period they formed 

 umbrageous woods and flowery glades that have left for our 

 inspection, admiration and instruction, beautifully preserved 

 leaves in great abundance, from which we see that many of our 

 familiar friends of the woodlands and the hedgerows were 

 flourishing long before the advent of man. 



Thus both the Animal and the Vegetable worlds were 

 enormously changed from Palaeozoic to Tertiary times rather 

 by the introduction of new and higher types than by the 

 extinction of species or genera. It is not too much to say that 

 if all the Pakeozoic species we know had continued in existence 

 to the present time, the difference of aspect of the whole fauna 

 and the whole flora of to-day would have been slight. The 



