OBSERVATIONS. 
369 
sembles the sandstone of which is composed the statue of the Old 
Memnon in Egypt ; and was found near the north base of the 
Black Mountains. As it is not a rolled pebble, it indicates, that 
in addition to basalt there are strata of ancient quartzose sandstone 
in this chain, which forms nearly the centre of the line along which 
the specimens above described have been collected. 
I 
