Vol. 52.] ANNIVERSARY ADDKESS OF THE PRESIDENT. CXVii 



could I do justice to the Ostracoda and Copepoda, while as regards 

 the Cirripedia, on which Charles Darwin laboured so long and 

 exhaustively, I have been silent, because I found the whole subject 

 of the Crustacea too large for the time at my disposal. 



To-day I have attempted, in a very imperfect manner, to bring 

 into the focus of my discourse a summary of the fossil Malaco- 

 straca, to which our modern Crustacea chiefly belong. It is true 

 that the evidences of the existence of this division prior to the 

 Mesozoic epoch are but few and scanty; nevertheless, even in Carbo- 

 niferous times, if not in still earlier eons, we catch a gleam of the 

 light of the living life-forms of to-day, shining clearly, though afar 

 off, down the corridors of time, revealing ancestral forms, the proto- 

 types of those which people so abundantly our modern seas, proving 

 that the living present and the far-distant past are indissoluble 

 linked together, and that the stream of lite has flowed, from its 

 parent source, through all time, at first in tiny rills and murmuring 

 streamlets, yet ever growing stronger, ' from running brooks to 

 rivers wide,' pressing ever and for ever, onward, from the river to 

 the sea. 



As to the minute details of the course which the evolution of 

 Crustacean life has followed in past times, we can, in many cases, 

 only infer, we cannot absolutely prove our proposition. 



Thus we have no doubt that the aquatic Eurypterida gave rise 

 to the terrestrial Scorpionida, but we cannot show any direct 

 evidence, because we have Eurypterus and Scorpio side by side in 

 Upper Silurian rocks, but the earlier evolutionary history is still 

 wanting. 



Again, Nebalia-like forms are most probably in the direct line of 

 the ancestry of the modern Malacostraca, and in the Carboniferous 

 period we have Oumacea-like forms, which have doubtless been 

 derived from Ceratiocaris and have given rise to higher Malaco- 

 straca ; but Macruran and other forms of Podophthalma and 

 Edriophthalma were already in existence in the Devonian, and 

 both Cumaceae and Nebaliae continue to esist unchanged at the 

 present day. 



Looked at broadly, however, the Crustacea show the same upward 

 and onward development which marks other living forms whose 

 history can be traced. The great extinct orders of Eurypterida and 

 Trilobita have disappeared — the other Entomostracan orders have 

 survived, but they no longer occupy the whole field : with the close 

 of Palaeozoic times the Malacostraca have developed in strength, and 



vol. lit. i 



