in the Counties of New-Haven and Litchfield. 233 
completely covered with a stratum of trap, which by some 
subsequent operation, was carved, united to its subjacent 
masses, into the present surface of the country, so as to be 
detached in some places, and to remain contiguous in oth- 
ers. Is there any reason (independent of the theory of 
universal formations, which I think must not be taken 
quite for granted, particularly in the late or upper forma- 
tions) for supposing that the trap of your neighbourhood, 
once was continuous over a much larger extent of coun- 
try ?” 
My present impression is that the trap of Connecticut 
and Massachusetts, has not extended over more country 
than it now occupies. But this subject may at a future time 
be resumed. 
In Southbury, numerous low, conical hills, of sand and 
gravel appeared, and formed the basis of the road. A 
Recurrence of primitive counerde=ahd ride to New-Haven. 
The gneiss again came in, in the southern part of South- 
bury, and northern part of Oxford, and its ledges continued 
for two or three miles east and South of Humphreysviile, 
where they form the bed and banks of the Naugatuck river, 
and contribute to diversify the scenery of that romantic 
spot. 
The rocks which intervene between this place and New- 
Haven, are the same ranges which, a few miles North, I pass- 
ed in the commencement of this tour. ‘They are, for two 
or three miles mica slate—then chlorite slate, much mixed 
with epidote and with spots of calcareous spar, and con- 
taining also beds of trap, which from its position must be 
primitive. At one place on the top of the high hill, from 
which we descend into New-Haven—the trap, perfectly 
distinct at the distance of a few feet from the chlorite slate, 
forms a,visible junction with it, and graduates into it so in- 
sensibly, that it is impossible to mark the line of distinction. 
Indeed, in its passage, it puts on very distinctly the appear- 
ance of greenstone slate. Upon these ranges of chlorite 
slate and clay slate, which succeed, lie vast isolated masses 
of trap, without any apparent connexion with other rocks; 
they seem to be of the same texture with the secondary 
greenstone or trap, and perhaps give some countenance to 
“Mr. Steinhauer’s suggestion. 
