56 THE LESSON OF EVOLUTION 



land as well, probably, as the worm burrows in the 

 quartzites of Holyhead, in Anglesey, must also be 

 referred to the Algorikian. 



Just below the base of the Cambrian a more varied 

 fauna occurs in two different parts of the world. In 

 the Salt Eange of the Punjab, Dr Fritz Noetling has 

 shown that there are four fossiliferous zones under- 

 lying the Olenellus fauna. These he calls (1) the 

 Neobolus zone, (2) the Upper Annelid Sandstone, (3) 

 the zone of Hyolithes, and (4) the Lower Annelid 

 Zone. Also Dr G. F. Mathew has described what he 

 calls the Protolenus fauna from St John, New Bruns- 

 wick. It contains thirteen species of Trilobites, be- 

 longing to six genera, as well as Ostracoda ; six 

 genera of pelagic Gastropoda, one doubtful Cephalopod 

 (Volbortkella), seven of Brachiopods, three of sponges, 

 and two of Foraminifera. Dr Mathew points out 

 that the Trilobites of this fauna can be distinguished 

 from those of Cambrian by having continuous eye- 

 lobes, and he says that the fauna as a whole is more 

 primitive and more pelagic in character than the 

 Olenellus fauna. 



Nevertheless, as the Olenellus fauna has not been 

 found in the neighbourhood, he thinks it possible 

 that the two might be contemporaneous, and that the 

 difference between them may be due to difference in 

 geographical station. 



It appears, therefore, that out of the eight sub- 

 kingdoms into which animals are divided by zoolo- 

 gists, six were represented in the pre-Cambrian times ; 

 but, until we come close up to the Cambrian, the 

 Protozoa and Porifera alone show much diversity ; and 

 they were certainly the dominant feature of the 



