INFUSOBIA. 93 
nished with small spines covered by a gelatinous substance. 
The axis of the Gorgoma is also of a horny consistence, 
and the fleshy matter by which it is covered contains de- 
tached particles, that are very friable in nearly the whole 
species. These are first placed, for an hour or two, in fresh 
water, and then dried, while the branches are held open. 
The same method is adopted with the Pennatule, or Sea | 
Pens. 
There is no difficulty in preserving the calcareous covering 
of the various Madrepores, &c.; all that is necessary is to 
immerse them in fresh water for some hours, so as to extract 
the salt, and then dry them thoroughly. 
In packing the small kinds, they may simply be placed in 
cotton ; but the ponderous and heavy ones should be fixed to 
the bottom of the case which is to contain them, This is done 
by passing cords between the branches at the base, and bringing 
these through holes bored in the bottom of the box, and fixed 
outside with nails. The feet of the Madrepores have some- 
times large openings, in which case, advantage is taken of 
them, to introduce pieces of wood into these natural aper- 
tures, and then nailing them to the bottom of the case. 
We have known many fine specimens of all kinds brought 
home, by gluing them to the sides and bottoms of packing- | 
boxes; and, when removed, the packing-bex is taken to 
pieces, and floated in water to moisten the glue, and the speci- — 
mens can easily be taken off. 
Sponges require merely to be soaked in fresh water, and | 
dried. No care is necessary in packing tiem. 
CLASS XIV—INFUSORIA., 
The animals of this Class are only tovnd in infusions, or in | 
water, and are so minute, that they are of no use in a pre- 
served state. 
