52 RELICS OF PRIMEVAL LIFE 



The fact that these problematical beds were ascer- 

 tained to be unconformable to the Cambrian, and the 

 peculiarity of their fossils, led to their being con- 

 stituted a separate group under the name EtcJie- 

 Diinian, which seems to represent a time and conditions 

 introductory to the Cambrian (Fig. lo). The fossils in 

 these beds are few and hard to find. Matthew has 

 kindly furnished me with the following list.^ The 

 Trilobites are conspicuous by their absence. Sea- 

 worms have left burrows, trails, and casts, which 

 probably represent several species (Fig. ii). A single 

 little shell (Volborthella) is supposed to be a pre- 

 cursor of the straight chambered shells allied to the 

 modern nautilus, which become so large and numer- 

 ous in succeeding periods. There are a few univalve 

 shell-fishes allied to modern sea-snails, a brachiopod 

 of the antique genus Obolus, some fragments sup- 

 posed to represent Cystideans, a rudimentary type of 

 the stalked sea-stars so abundant later, spicules of 

 sponges and minute Protozoa, with shells not unlike 

 those of their modern successors. This meagre list 

 sums up the forms of life known in the Etcheminian 

 of this district, one in which the Cambrian beds 



* " Transactions Royal Society of Canada," vol. vii. 



