318 The Taconic Question Restated. [ April 
in different regions, it appears to rest in unconformable stratifica- 
tion. It is at the same timé overlaid in New Brunswick by the 
Cambrian (Menevian) slates of St. John, and in very many parts 
of the Appalachian valley by the Cambrian Graywacke, and 
elsewhere in that region by the Silurian (Oneida) sandstone, and 
apparently by the Ordovician (Trenton) limestone, as is also the 
case in Ontario. 
§ 36. It became evident to the writer after many years of 
. study of these rocks, that'the attempt to set aside this great 
factor in American stratigraphy,—already recognized by Maclire, 
by Eaton, and by Emmons,—and to regard it, in conformity with 
the fancies of the metamorphic school, alternately as altered 
Cambrian, Ordovician, Silurian, Devonian, Carboniferous, and 
even Triassic,—was, like similar attempts in British and in Euro- 
pean geology, a grave error. 
The distinctness and unity of this great series of crystalline 
stratified rocks being maintained, a name for it was needed, and 
that of Lower Taconic given by Emmons was at hand. His 
Upper Taconic had by himself, and by others, been recognized 
as the equivalent of what had been previously designated Cam- 
brian, a name which it was thought it should henceforth bear. 
To prevent confusion in nomenclature, to secure uniformity in 
terminology, and to connect the name of Emmons with his great 
achievements in American stratigraphy, the writer, in 1878, pro- 
posed for the Lower Taconic the name of Taconian, which he 
has since adopted. 
$ 37. These rocks, although below the recognized Cambrian 
horizon, and, unlike them, essentially crystalline, are not desti- 
tute of the evidences of organic life. There are many reasons, 
both direct and indirect, apart from the existence of Eozoon, for 
believing that “the dawn of life,” as Dawson has happily called 
it, began long before Taconian time. The typical Scolithus 
linearis of the basic quartzites of the Taconian ,—although, as 
I have long since pointed out, very distinct from the somewhat 
similar markings (probably of two or more distinct species) found 
in the Cambrian (Potsdam) of the Ottawa and Mississippi basins, 
—is the more significant from the fact that it is found throughout 
the Appalachian valley, and, moreover, that something very like 
it, if not identical, occurs in the Taconian limestone alike in Penn- 
sylvania and in South Carolina, as well as in the Taconian quartz- 
