IMPERFECTION OF THE GEOLOGICAL RECORD 4? 



accompanied perhaps by earthquake waves, and not improb- 

 ably by the action of heavy coast ice. The result is that mud 

 rocks now in the form of black, grey, and red shales arid slates 

 alternate with thick and irregular beds of hard sandstone, 

 sometimes so coarse that it resembles the angular debris of the 

 first treatment of quartz in a crusher. With these sandstones 

 are thick and still more irregular conglomerates formed of 

 pebbles and boulders of all sizes, up to several feet in diameter, 

 some of which are of older limestones containing Cambrian 

 fossils, while others are of quartzite or of igneous or volcanic 

 rocks. 



The whole formation, as presented at Metis, is of the most 

 unpromising character as regards fossils, and after visiting the 

 place for ten years, and taking many long walks along the 

 shore and into the interior, and scrutinising every exposure, I 

 had found nothing more interesting than a few fragments of 

 graptolites, little zoophytes, ancient representatives of our sea 

 mosses, and which are quite characteristic of several portions 

 of the Quebec Group. With these were some marks of 

 fucoids and tracks or burrows of worms. The explorers of the 

 Geological Survey had been equally unsuccessful. 



Quite accidentally a new light broke upon these unpromis- 

 ing rocks. My friend, Dr. Harrington, strolling one day on 

 the shore, sat down to rest on a stone, and picked up a piece 

 of black slate lying at his feet. He noticed on it some faintly 

 traced lines which seemed peculiar. He put it in his pocket 

 and showed it to me. On examination with a lens it proved 

 to have on it a few spicules of a hexactinellid sponge little 

 crosses forming a sort of mesh or lattice-work similar to that 

 which Salter had many years before found in the Cambrian 

 rocks of Wales, and had named Protospongia the first sponge. 

 The discovery seemed worth following up, and we took an 

 early opportunity of proceeding to the place, where, after some 

 search, we succeeded in tracing the loose pieces to a ledge of 



