174 Professor SepGwick on the 
SecT. 3. 
No. Feet. 
(1.) Trap forming a fine lofty escarpment. 
(2.) A bed, every portion of which appears in the 
greatest confusion. Some parts as full of 
irregular cells and pores as a piece of slag: 
other parts resembling hornstone, chert, or 
porcelain jasper, mixed with nodules, beds, 
and irregular concretions of granular lime- 
stone. Whole thickness. . 366 Aste cl S 
(3.) Slate-clay in a state of ark ae 10 
(4.) Softer slate-clay, apparently decomposing 4 
(5.) Dark impure limestone .... .... Hoste eee | 
(6.) Various beds which appear to ovine “bhen | 
slirhtly aéted ones. +2.) JI 2208. GU. os 9 
(7.) Dark encrinite limestone m the ordinary state 4 
(8) »Slaty,; sandstome.-sps%- 540. th ieoees ie Je eh ie 
(9); Hard: sandstone jawer 2,212 Pe. RB). 6 
(10.) A bed appearing at the base of the cliff, and 
in the edge of the river, composed of impure 
slate-clay aud argillaceous limestone, mixed 
with grains and small pebbles of quartz. 
The three preceding sections are copied from memoranda, 
made upon the spot in the year 1822. The numbers are not the 
result of any actual measurement, and are only to be considered | 
as approximations. If the sections convey only a correct general 
notion of the strata immediately below the great escarpment of 
the trap, they will answer the purpose intended. 
meals I now proceed to describe some of the specimens derived 
the Beds under from the three last-mentioned localities. The beds immediately 
Ne Trp under the trap, are of the greatest interest, and they so nearly 
resemble substances acted on by fire, that the practical men by 
