86 The American Geologist. August, i89i 
species and 12 varieties of fossils from this formation in America. 
In several localities in this country and in Europe no unconformity 
is found between the Lower and INIiddle Cam])rian, and there is at 
present no wa}- of accounting for the change from the Olenellus 
to the overlj'ing I*aradoxides fauna. 
A number of new forms are described in the last section of this 
paper, one of them, Trachjum vetusfinn by Dawson and the others 
b}' Mr. Walcott. The figures illustrating the species are, in gen- 
eral, excellent. Students interested in the problematic Cruziana 
will find a number of plates illustrating various forms it assumes. 
The belief is expressed that many of the so-called species were 
formed by one kind of animal, while even had specific difl'erences 
existed in the animals themselves, those would not be manifest in 
the trails or burrows made by them. The trilobites are placed in 
sixteen genera, and number fiftj-'three species, forming less than 
one-third of the entire fauna. Under Olenellus nine species are 
recognized, these being referred to Olenellus proper, and the sub- 
genera Mesonacis and Holmla. The species are illustrated on a 
series of twelve plates, which are most valuable for comparison. 
Tlie genus Atops of Emmons is discarded and replaced b}- ConO' 
coryphe. upon the ground that it was so badlj' defined and figured 
as to be unrecognizable until the discover}- of new specimens in 
the tj'pe localit}" over forty 3-ears after its original discovery. 
The paper will doubtless create discussion, and while some of 
the conclusions of the author may not be accepted by all paleon- 
tologists,' something that can scarcely' be expected, certainh- all 
will be glad to have this full presentation. 
THE FAUNA WITH GONIATITES INTUMESCENS, 
BEVKKH. IN WESTERN NEW YORK. 
By .7. M. Clarke, Albany, N. Y. 
Some years ago the writer had the opportunity-* of discussing at 
considerable length the faunas of the Genesee shales and those 
beds of the " Portage group" w-hich were designated by professor 
Hall, in 1840, the " Cashaqua shale " and the " Gardeau or Lower 
Fucoidal group." The data accessible at the time of this work 
had been collated mainly from the southern area of Ontario and 
Livingston counties, incidentally from Yates county on the east 
*BiinyNo. 1(5, U. S. Geological Survey: The Higher Devonian Fauna 
of Ontario county, N. Y. 188.5. 
