100 Rev. Dr Fleming’s Gleanings qf Natural History.- 
were eagerly offered for sale. Among these, we picked out the* 
following minerals. 1. Calcareous Spar, of a brownish colour. 
% Cuhizite, transparent, and regularly crystallized ; and, when 
occurring in the same cavity with the preceding, usually occu» 
pying the place nearest the walls. 3. A mineral resembling 
Thomsonite, but not yet sufficiently examined. Only two small 
specimens of this mineral were observed, though eagerly sought 
after. Hence it is probably of rare occurrence. These had 
formed a coating on the interior of a cavity in the amygda* 
loid,. and exhibited perfect crystals shooting from the base. 
4. Arragonite. This occurs massive, of a white, grey, or pale- 
green colour, and scopiformly narrow radiated structure. Even 
where much mixed with the rock,^ it still appears capable of ex- 
ercising that influence which produces its radiated appearance. 
Leaving the Causeway, we bent our course towards Portrush, 
where we again joined the vessel, visiting, in our progress, the 
extensive .quarries of chalk, and glancing at the amygdaloid, 
with its incumbent augite-greenstone in the neighbourhood of 
the harbour; 
On the S6th, we landed at the light-house situate at the west 
side of the Mull of Cantyre. The strata in the immediate 
neighbourhood, are of mica-slate, stretching in a south-westerly 
direction, and dipping eastward. The slate is thick slaty, and 
consists of a basis of grey quartz and silvery mica, with oblong, 
opake and translucent concretions of quartz. The same kind of 
mica-slate likewise prevails to the north of the town of Camp- 
beltown, and occupying a similar position. At the latter place, 
how'ever, it in general contains more mica,, and is thin slaty, and 
characteristically waved. Eastward from a quarry, near the 
town, of this mica-slate, and in conformable position, and even 
interstratifled therewith, are numerous beds of sandstone and 
trap conglomerate, foliated limestone, red slate-clay, and red 
sandstone. Near the extremity of the north side of the bay, 
these beds are covered with greenstone and amygdaloid, and a 
coarse clayey basalt. The latter rock is, in some places, colum- 
nar ; but the columns, which are vertical, are frequently sepa- 
rated several inches from one another, the interval being filled 
up with ferruginous clay-green earth, calcareous-spar, or a sub- 
stance resembling sandstone. Compact and heinatitic red iron- 
