R. D. Irving — Is there a Huronian Group f 373 



ferred to, no fossils whatever have been met with. in these 

 ancient formations. The only things, then, that we can affirm 

 with regard to the life of these early periods are, that it ex- 

 isted, and that we know nothing of its nature. I have already 

 indicated my anticipation of the discovery of the remains of 

 faunae earlier than any of those with which we are now "ac- 

 quainted ; though it may be that those are correct who imagine 

 that no such remains will ever be brought to light, because of 

 the probability that the earlier forms of life were unprovided 

 with hard parts. 



The general term to be used to cover the great pre-Cam- 

 brian interval should then express the existence of this early 

 life, and our present ignorance with regard to its nature. Dur- 

 ing the year and a half that such an addition to geological 

 nomenclature has been under discussion between myself and 

 several of my fellow-geologists, many terms have been proposed 

 and discussed. Some of these have been rejected because, 

 though sufficiently appropriate, they have already been too 

 generally used in other connections. Others again seemed 

 inadmissible because, while expressing well the idea to be 

 presented, they were made up of derivatives from the Greek 

 not ordinarily met with in the English language, and were too 

 cumbersome and pedantic in sound. Others again, like Pro- 

 ierozoic (nporepoc;, earlier), suggested by Mr. Emmons, while 

 simple and made from a Greek word of not too uncommon use, 

 seemed to fail in covering the ground sufficiently. I have 

 therefore been disposed to return to a term early proposed by 

 Professor T. C Chamberlin, to whom indeed is to be assigned 

 the first suggestion of the use of a single name to cover all of 



DO CD 



the pre-Cambrian fragmentals. I would advocate therefore, 

 the use of the term Agnotozoic (dyucoroc, unknown ; ^coij, life), 

 to cover all of the geological interval lying between the base 

 of the Cambrian and the summit of the Archaean crystallines. 

 This proposal I make with a good deal of hesitation, and only 

 after consultation with several of my fellow geologists. Not 

 that I have any question as to the need of such a term, nor as 

 to the hitherto too much ignored truth which I conceive it to 

 express ; my hesitation arises simply from the feeling that so 

 important an addition to geological nomenclature should hardly 

 be attempted by any single individual. 



I ought not to conclude without alluding to one objection to 

 the proposed new term — or indeed to any term designed to 

 have the same scope — brought forward by one of my col- 

 leagues ; this is, that while the upper limit of the proposed 

 Agnotozoic is clearly enough defined by the basal Cambrian 

 fauna above, the lower limit is not similarly defined, and that 

 if we accept the view of some geologists that metamorphism 



