176 C. LAPWORTH ON GRAPTOLITES 
were most properly referred to the period of the Utica formation, but it is imposssible to 
demonstrate the correctness of this reference in the present state of our knowledge. The 
zones represented range from the Calciferous to the Trenton-Utica, and their sequence 
appears identical with that of their representatives in Great Britain and northern Europe. 
But while we cannot yet actually prove the existence of any general unconformity or 
extraordinary dislocation, the normal sequence of the strata has been generally-inverted, 
and appears to be locally interrupted by overturned folds and inverted faults. 
Sixthly.—In western America, precisely as in some parts of the British Isles, the Lower 
Paleozoic rocks shew great variations in their lithological and petrographical character- 
istics in different geographical areas. In Great Britain (compare my papers on the Moffat 
Series and the Girvan Succession), this variation appears to be more or less related to the 
varying distance from the ancient Palæozoic shore-line —each formation graduating from 
a massive assemblage of coarse materials to a thin sheet of very fine silt, when followed 
in certain special directions. In the same way, the thick shore-derived mechanical 
deposits of much later formations have long been recognized as graduating into, and 
becoming represented by, their organically derived deposits (limestone and chalk, etc). 
I have for years held the opinion that the entire, more or less Calcareous series of the 
Lower Paleozoic rocks of New York State, and of the region west and north of the St. 
Lawrence, from the Potsdam below, to the Lorraine (Hudson River Group) above, was 
originally represented, formation above formation, in the vastly thicker, sandy, flaggy and 
shaly strata lying to the east and south of the great St. Lawrence and Hudson River Valley, 
from Gaspé to New York (i.e. in the strata to the east of “Logan’s Line,” generally 
lumped together by American geologists, as Quebec and Hudson River Groups). In 
the western Toronto-Ottawa calcareous formations, the usual Lower Paleozoic fossils 
(Brachiopoda, Crustacea, etc.) are present in abundance; the original sequence is undis- 
turbed by folding or dislocation; and as a consequence, our knowledge of the chrono- 
logical relationship of the various recognizable rock formations is fairly complete. In the 
eastern Quebec-Gaspé series, on the contrary, Brachiopoda and Crustacea are almost 
wholly wanting; the original sequence is almost hopelessly obscured by faults, folds, 
overfaults and inversions, while suggestions of possible unconformabilities and overlaps 
add to the bewildering confusion. But these eastern non-calcareous rocks contain an 
abundance of Graptolites fairly easy of identification, and quite as valuable chronologic- 
ally as the species of Brachiopoda and Crustacea. Many of these Graptolithina have their 
geological dates fixed by their known horizons among the Calcareous rocks of New York 
and Canada; others by their known systematic places in the equivalent European suc- 
cession. Le. 
In the careful study of the geographical and geological distribution of the several 
horizons of these Graptolites in the extensive convoluted rock series of the Eastern 
Townships, lies the solution of the great geological enigma of the Quebec Group and its 
puzzling associates. We shall not be able to parallel the eastern and western series, 
formation for formation, until we know more of the Graptolitic faunas of the Chazy, 
Black River, Trenton, Utica and Lorraine formations themselves, where they lie flat and 
undisturbed, and can compare them with those of their European equivalents. This is a 
work that ought to be at once taken up in serious earnest by American geologists, and 
carried on, stage by stage, with the study of the equivalent rocks of the convoluted 
