252 Messrs. Jackson and Alger on the 
We also met with interesting specimens of chalcedony, curi- 
ously marked by those regular stripes, or alternations of different 
shades of color, that are exhibited in the onyx agates of the 
lapidaries. They are sometimes arranged in little zones, which, 
if cut and polished, would resemble the stones sold under the 
name of “ onyx eyes.” ‘The chalcedony is sometimes converted, 
apparently, by decomposition, into an adhesive cacholong, and is 
earthy and opaque. These minerals, like most of the others we 
shall mention, are obtained most conveniently among the loose 
masses of rock that skirt the shore; and it is fortunate for the 
collector of these objects, that he has thus at his ready command, 
treasures which would otherwise cost him great labor in obtain- 
ing, and for which, in clambering up the lofty precipices, he 
would besides expose himself to the no little danger of falling 
with the loose masses to which he may cling for support. 
About one mile east of this locality, the amygdaloid abounds 
with analcime, in dodecahedral crystals transparent and colorless ; 
but sometimes of an apple green color internally, and invested 
with on opaque white crust on their surfaces. But no separating 
line is seen between them as in the case of the apophyllite. 
Accompanying the analcime, we found a mineral resembling that 
variety of mesotype called needlestone. It occurs in tetrahedral 
prisms terminated by low pyramids, formed by four triangular 
planes resting onthe terminal edges. One of the terminal planes 
is often extended at the expense of the others, which it some- 
times nearly obliterates. It occurs in radiating and interwoven 
groups of crystals that proceed from a centre, which is sufficiently 
compact to yield a splintery fracture, and is white like ivory ; 
they are transparent and colorless, have a remarkable vitreous 
lustre, and are sufficiently hard to scratch glass. They are often 
