Fauna of the Lower Camribrian. — James. 83 
ion of the Cambrian : a subdivision of tlie geological scale that, 
a few years ago, was regarded as of scarcely any importance even 
if it were really known , and a subdivision that has scarcely vet 
found its way into geological text-books. It contains material for 
the earnest considerations of geologists of America, and if its con- 
clusions be accepted, it must very materially alter man}- concep- 
tions at present entertained. 
In the two previous publications above referred to^ Mr. Walcott 
considered the rocks containing Olenellus as of Middle Cambrian, 
and those containing Paradox ides as of Lower Cambrian age. A 
careful studj' of a complete section in Newfoundland revealed the 
fact that in realit}^ Olenellus occupied rocks below those containing 
Paradoxides, and were, consequently older. He was the first to 
announce the discover}', and promptly corrected the previously er- 
roneous idea. The question of the adoption of the term ' ' Cam- 
brian ■■ in preference to '■ Taconic " is not entered into, though the 
former is definitely adopted. A careful study of the literature has 
convinced him, however, as it would those who give it equal at- 
tention, that Cambrian was applied by Sedgwick to rocks below 
those containing a typical Lower Silurian fauna, as the Taconic 
Was applied by Emmons : and Cambrian has eight years priority 
over Taconic. 
The scope of the paper under review is wide, including a bibli- 
graphy, an historical review of the literature, and a discussion of 
the results from both a geological and a zoological standpoint. 
Under the head of "Historical Review," we find notices of the 
work of prominent investigators from the time of Amos Eaton in 
1818 down to the year 1890. It is true Eaton did not recognize 
the Cambrian as such in his early work, but inasmuch as the local- 
ities studied by him are now known to contain rocks of Lower 
Cambrian age, it was considered fitting to begin with his work. 
The first fossils were found in rocks of this age by Dr. Asa Fitch 
in 1844. They were described by Emmons in the same year, and 
referred by him to his Taconic system. Barrande in 18C0 identi- 
fied these fossils as belonging to the Primordial Period, and 
credited Emmons with the discovery of their stratigraphical posi- 
tion. Mr. Walcott, however, considers that the credit should be 
given to Barrande, who he says, "was misled by the evidence 
advanced by Dr. Emmons, which was based on the erroneous inter- 
»These are Bulletins No. 10 and No. 30 of the U. S. Geol. Survey, pub- 
lished in 1884 and 188r,. 
