Meo Ute (Ge QURIELE JC 
io) 
(e) 
bo 
NOTES TO ORDOVICIAN TABLE. 
signifies range admitted by all observers. 
signifies fide H. M. Ami. 
signifies fide R. R. Gurley. 
signifies fide James Hall. 
signifies fade Charles Lapworth. 
signifies fde G. F. Matthew. 
signifies fide S. A. Miller. 
signifies fide E. O. Ulrich. 
signifies fide C. D. Walcott. 
Wh signifies 7de R. P. Whitfield. 
1 Gl Ed [oll Ec 
t Calciferous—The table given here is the result of a study of a considerable 
quantity of material from four American localities, as follows: 
(a) The Point Levis shales. Two collections were examined. The first —from 
the main zone—was a very large one, containing a number of characteristic species, 
among which Dichograpsus flexilis and Phyllograptus tlicifolius var. were conspicuous. 
_ They occur in black shale. 
(6) The second and smaller collection from the Point Levis shales was from a 
hard ringing iron-gray shale, lithologically quite different from the much softer, black 
shale of the first collection; locality, 14% miles north of the East Railway Station, 
Levis, Canada. As will be seen from the table, the fauna was strikingly different 
from that found in the softer, black shale. It was remarkable not so much for the 
species present (though the Diplograpside seem highly characteristic), as for those 
absent. Indeed, it is hardly possible to examine a fragment of the black shale without 
finding a number of species which appear never to occur in the hard gray shale. 
Analogy with British stratigraphy suggests that the difference is one of horizon 
and this view is reinforced by an examination of collections from the Calciferous beds 
in Nevada and Arkansas, the fauna of which agrees in a general way with that of 
the hard, gray Point Levis shale, and differs widely from that found in the black shale 
in the same locality. Further, as in Europe, so in Nevada, Didymograpsus .bifidus 
marks a distinctly higher horizon. 
Perhaps intermediate faunas (implying intermediate horizons) may exist. Some 
of those given by Ami appear to indicate that such is the case (see below), but I 
think the main divisions will not thereby be obscured. The species whose horizons 
are indicated in the table are those which I have myself identified. The exact ranges 
of the others are unknown, being merely Calciferous generally. 
(c) A large collection from the Pifion Range, at the crossing of the Eureka and 
Palisade Railroad, at Summit, Nevada; collector, C. D. Walcott. This collection 
shows some very interesting and unique features, notably, the presence of Phydlo- 
graptus entirely unaccompanied by any traces of 7etragrapsus or more highly com- 
pound dichograptid genera, the presence of Chmacograptus and Glossograpsus, and 
the extreme profusion of individuals of Caryocartés which amount to more than half 
the entire number of specimens. 
(7) A rather small collection from Arkansas, in which, however, a number of 
Calciferous species could be made out. 
