216 
remark that the spines have the appearance of having beer 
stuck on, probably owing to their being attached to part of 
the outer shell which is worn away at their bases, the spines 
sometimes being gone also. These shells or casts being 
chiefly pyrites decompose easily, exuding the flowers of 
Sulphur if in a dry place, or Sulphate of Iron if wet, when 
they have the sulphurous odour and occasionally fall to 
pieces, which may be the case with this large shell, the 
odour and sulphur exuding from its sides being signs of it. 
In such when the subjects are sufficiently desirable they 
may be kept under water in stopped bottles. The little 
outline at the bottom shows the contour of one of the septa 
and the siphuncle. 
