400 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
Campbell (’63) gave a generalized section across the series, and 
divided the rocks into a lower or quartzite group and an upper or 
slate group. He regarded the cross-leads as younger than the 
bedded veins. 
Hartt (’64) proved the pre-Carboniferous age of the concentra¬ 
tion of gold, by its presence in lower Carboniferous conglomerate, 
in boulders of the metamorphic series. The leads in the lower 
rocks end abruptly upward against the conglomerate. 
Dawson (’68) -mapped the outlines of the series in a general way,, 
and called attention to the clay slates near the Atlantic coast. 
Hunt (’68) called the bedded veins contemporary sedimentary 
deposits, as did also Hind a year later (’69). In the latter paper 
the first announcement of fossils was made, the forms given being 
JPalaeotrochus ynajor and P. minor (Emmons), with accompanying 
concretions. Many similar reports have been made since, but in no 
case is the status of the form well established. As yet, nothing has 
been found so clearly organic that it is of the least value for evi¬ 
dence. By means of these fossils Hind sought to establish the 
series as upper Potsdam and lower Calciferous, and equivalent to 
the gold-bearing rocks of North Carolina described by Dr. Emmons. 
He also mentioned eruptive bedded rocks at Waverly, calling them 
“ diorites, diabase, dolerite, etc.” In the next year (’70 , ’70 b , ’70 d ) 
he gave the thickness of the whole series as 12,000 feet, with 
Huronian strata below. The granite which protrudes through it 
was stated to be sedimentary and older than the auriferous rocks, 
its apparent intrusion having been caused by up-faulting while in a 
23lastic condition. 
Selwyn (’72) considered that the opening and filling of the 
stratification planes, the slaty cleavage, and the rolling of the quartz 
were all produced by the same force. The veins are thus true 
veins, and younger than the country-rock. He mentioned the dis¬ 
covery by himself of Eophyton at the Oven's Bluff; and from this 
and other evidence concluded that the series “ resembles the Cam¬ 
brian and the Lingula-flag series of north Wales.” 
Dawson (’78) called the rocks Cambrian, but admitted the 
imperfection of the evidence. 
Poole (’80) found horses of slate in veins at Tangier, and stringers 
running into the country-rock; thus proving beyond doubt that the 
deposits are true veins. At the same place a bedded lead is capped 
and penetrated by granite, showing the greater age of the former. 
