4 
e 
clearly exposed at several points, and are favorable to the view 
that the melaphyrs are contemporaneous. It consists, like the 
other beds of tuff, almost wholly of more or less angular and 
imperfectly assorted fragments of melaphyr imbedded in a dis- 
tinctly stratified cement of the same character. On the west 
side of the hill it rests directly upon the second melaphyr ; ? 
while in the vicinity of Valley Beach the second tuff and the 
third or amygdaloidal melaphyr are interposed, as already ex- 
plained. East of Valley Beach it is scantily exposed, and can 
not be traced much beyond the Waverly House. But it is 
here, seemingly, somewhat interstratified or mingled with the 
underlying amygdaloidal melaphyr. 
Above the last described or third tuff comes the great body 
of melaphyr forming all the remaining portions of Atlantic and 
Centre Hills and extending south to Conglomerate Plateau, as 
shown on the map. The outcrops are so numerous over this 
area that there is absolutely no room to doubt the essential 
continuity of the melaphyr. Its breadth, measured from the 
third tuff, along Valley Beach Avenue, is nearly 1400 feet, cor- 
responding to a probable thickness of more than 300 feet. Ог, 
classing the three beds of tuff as fragmental lavas, as the facts 
appear to warrant, and thus regarding the volcanic series as 
essentially continuous back to the conglomerate on Long Beach 
Rock, the breadth of the entire series of three tuffs and four 
melaphyrs is, in round numbers, at least 1800 feet, and thick- 
ness 450 feet. 
The great mass of melaphyr above the third tuff is fairly 
uniform lithologically. It is usually more or less brecciated, 
with numerous highly irregular and limited segregations of 
vitreous quartz and chalcedony, as well as epidote. Dut 
sometimes it is much more distinctly brecciated, especially im- ` 
mediately above the third tuff. On Atlantic and Centre Hills 
it is rarely amygdaloidal or quite compact in texture. Near 
the southern border of the melaphyr area, on the north side of 
Willow Ledge Hill, it encloses about twenty feet in thickness | 
of greenish tuff and agglomerate. The green arenaceous tuft is 
