LOWER CAMBRIAN TERRANE 333 



' Etcheminian' is more primitive and more pelagic than the 

 Olenellus fauna. He speculates as to whether the two faunas 

 were contemporary, and remarks that his conjectures are based 

 "on 0U7' present knowledge of its (Protolenus fauna) constitu- 

 tion and peculiarities. Possibly further knowledge may make 

 it necessary to modify these remarks in some particulars, but 

 the fauna is now so well shown by the numerous species per- 

 taining to it, that these modifications cannot essentially change 

 its aspect, or obliterate its peculiar and essential characters."^ 



In 1899 he concluded, from the evidence known to him, that 

 the ' Etcheminian' fauna is distinct from the Cambrian faunas. 



The uniformity of conditions attending the depositions of the 

 Etcheminian terrane throughout the Atlantic Coast province of 

 the Cambrian is surprising, and points to a quiescent period of 

 long continuance during which the Hyolithidee and Capulidag 

 developed so as to become the dominant types of the animal 

 world, while the Brachiopods, the Lamellibranchs and the other 

 Gasteropods still were puny and insignificant. The Crustacea, 

 so far as we know, were represented only by one Phyllocarid, 

 and the trilobites so far have not been recognized at all." 



This was followed by a paper on the Etcheminian fauna of 

 Newfoundland, giving a description of new genera and species, 

 and a brief summary, as follows : 



The peculiarities of this fauna as distinguished from the 

 Cambrian are the following : 



1. Great preponderance of the tube worms (Hyolithida, etc.). 



2. Absence or rarity of trilobites. 



3. Minuteness of the Gasteropods except Patellidas. 



4. Minuteness of the Brachiopods. 



5. Minuteness of the Crustaceans. 



The two special types of the Etcheminian fauna are, among 

 the Hyolithidae Orthotheca bayonet^ and among the Gasteropoda 

 Randomia aurorcR. The minuteness of the Lamellibranchs is 

 not peculiar to the Etcheminian, as the Cambrian species are not 

 much larger." 



This last paper was soon followed by a more detailed descrip- 

 tion of the genera and species of the ' Etcheminian ' fauna, with 



iLoc. cit., p. 153. 



2 Paleozoic Terrane Beneath the Cambrian: Annals New York Acad. Sci., 

 Vol. XII, 1899, pp. 52-54. 



'Bull. Nat. Hist. Soc. New Brunswick, Vol. IV, 1899, p. 195. 



Proc. Wash. Acad. Sci., January, 1900. 



