48 IMPERFECTION OF THE GEOLOGICAL RECORD 



shale on the beach, where there was a little band, only about an 

 inch thick, stored with remains of sponges, a small bivalve shell 

 and a slender branching seaweed. This was one small layer 

 in reefs of slate more than one hundred feet thick. We sub- 

 sequently found two other thin layers, but less productive. 

 Tools and workmen were procured, and we proceeded to 

 quarry in the reef, taking out at low tide as large slabs as 

 possible of the most productive layer, and carefully splitting 

 these up. The results, as published in the Transactions of 

 the Royal Society of Canada, 1 show more than twelve species 

 of siliceous sponges belonging to six genera, besides fragments 

 indicating other species, and all of these living at one time on 

 a very limited space of what is practically a single surface of 

 muddy sea-bottom. 2 The specimens show the parts of these 

 ancient sponges much more perfectly than they were previously 

 known, and indeed, enable many of them to be perfectly re- 

 stored. They for the first time connect the modern siliceous 

 sponges of the deep sea with those that flourished on the old 

 sea-bottom of the early Cambro-Silurian, and thus bridge over 

 a great, gap in the history of this low form of life, showing that 

 the principles of construction embodied in the remarkable 

 and beautiful siliceous sponges, like Euplectella, the " Venus 

 flower-basket," now dredged from the deep sea, were already 

 perfectly carried out in this far-back beginning of life. This 

 little discovery further indicates that portions of the older 

 Palaeozoic sea-bottoms were as well stored with a varied 

 sponge life as those of any part of the modern ocean. I 

 figure 3 a number of species, remains of all of which may be 

 gathered from a few yards of a single surface at Little Metis. 

 The multitude of interesting details embodied in all this it is 

 impossible to enter into here, but may be judged of from 



1 Additional collections made in 1892 show two or three additional 

 species, one of thein the type of a new and remarkable genus. 

 * 1889, section iv. p. 39. 8 Frontispiece to chapter. 



