296 



PALEOZOIC TIME, 



(c.) Eastern-border region. — In Nova Scotia and New Brunswick, the Subcar- 

 boniferous rocks are, below, red sandstones, conglomerates, and red and green marlytes, 

 of two groups: the Horton series, consisting of red sandstones, conglomerates, red and 

 green marlytes; and, above these, the Windsor series, consisting of thick beds of 

 limestones, full of fossils, with some red marlytes, and beds of gypsum, affording the ■ 

 gypsum exported from Nova Scotia and New Brunswick. Thus the upper part of the 

 Subcarboniferous is the calcareous part, as in Ohio, Tennessee, and Western Virginia. 

 The estimated thickness is 6,000 feet. To the north, toward the Archaean, the lime- 

 stones fail ; and, instead, the rocks are to" a greater extent a coarse conglomerate. To 

 the south, limestones prevail. The localities of these beds, mentioned by Dawson, are 

 the Carboniferous districts of northern Cumberland, Pictou, Colchester, and Hants, 

 Richmond County and southern Inverness, Victoria, and Cape Breton. The best ex- 

 posures of the lower or Horton series are at Horton Bluff, Hillsborough, and other 

 places in southern New Brunswick. 



In the lower part of these Subcarboniferous beds, as in those of Virginia, there are, 

 on a small scale, "false " Coal measures, and, in one instance, a bed of erect trees, 

 under-clays, and thin coal seams; and the same beds contain numerous remains of 

 fishes. The fish-bearing shales of Albert Mine, New Brunswick, are of this period. 

 (Dawson.) This mine affords a peculiar coaly material, pitch-like in aspect, which has 

 been named Albertite; it fills a fissure, instead of constituting a true coal-bed. 



{/.) Rocky- Mountain and Pacific-border regions. — Over large portions of these 

 regions, the limestones of the Subcarboniferous have not been distinguished from those 

 of the following epoch. In most cases, their recognition only waits for the more care- 

 ful study of the fossils; but, at some points, they appear to be really wanting. They 

 have been identified in the Elk Mountains, and other ranges of the crest chain of the 

 mountains in western Colorado; on the eastern slopes of the Wind River Mountains, in 

 Wyoming. In Montana, at " Old Baldy," near Virginia City, there are fossils of the 

 Chester group, and probably the Lower Subcarboniferous beds are also present. 

 (Meek.) In Idaho, near Fort Hall, Bradley found masses of limestone filled with 

 minute shells, many species of which Meek has identified with forms characteristic of 

 the oolitic beds of the St. Louis group, at Spergen Hill, Indiana. In Utah, the same 

 beds occur in the limestones which surround the silver mines of the Wahsatch and 

 Oquirrh ranges. From the latter range, near Lake Utah, a species of Arcliimedes 

 has been reported. The Carboniferous limestones reported from the Humboldt and 

 other ranges of the Great Basin, doubtless include beds properly referable to the Sub- 

 carboniferous, though G. K. Gilbert reports that, over the southern portion of this 

 area, he has been unable to separate them from the beds including typical Coal- 

 measure fossils. In northern California, the Subcarboniferous occurs in the Gray 

 Mountains near Bass's Ranch, and at Pence's, eighty miles farther south. In the Gray 

 Mountains, the limestone is 1,000 feet thick, forming part of* the auriferous series, and 

 is doubtingly referred by Meek to the St. Louis horizon. 



n. Life. 

 1. Plants. 



The sea-weeds included the Spirophyton, which first appeared under 

 the species S. cauda-galli, in the Lower Devonian, and characterized 

 the Cauda-galli grit (p. 254) : it is found in the sandstone of Ohio. 



The terrestrial vegetation of the Subcarboniferous period was very 

 similar to that of the lower part of the Carboniferous. There were 

 Lycopods, of the tribes of Lepidodrencton and Sigillaria, and various 

 Ferns, Conifers, and Calamites. The vegetation may have been as 



