1890.) Jhicroscopy. 861. 
Cerianthus should be killed with concentrated acetic acid, placing 
it as soon as possible in weak alcohol, in which it should be suspended 
so that the tentacles may float freely, if necessary disentangling them. 
Corals should be allowed to expand fully, and should then be 
killed with boiling solution of corrosive sublimate and acetic acid used 
in volume equal to that of the sea-water containing the coral. The 
colony should then be transferred to 35 per cent. alcohol, some of this 
fluid being injected into the mouth of each polyp. The injection 
should be repeated at every change of the alcohol, and the specimens 
should be preserved in 7o per cent. alcohol, after washing them well in 
iodized alcohol. 
Hydromeduse.—For the hydroid colonies the best fixing teagent is hot 
corrosive sublimate. The smaller Tubularian medusz should be killed 
either in the mixture of corrosive sublimate and acetic acid, or in Klein- 
-enberg’s picrosulphuric acid. rger forms may be fixed with concen- 
trated acetic acid, and then allowed to fall into a tube containing the 
alcohol and chromic acid mixture, in which they are gently agitated 
and allowed to remain for fifteen minutes, after which they should be 
transferred to 35 per cent. alcohol and gradually carried to 70 per 
cent. 
Small Campanularian medusz, e.g., Eucofpe and Obelia, may be killed 
in the mixture of copper sulphate and corrosive sublimate. Zguorea 
should be killed.with concentrated acetic acid, and immediately trans- 
ferred to chrom-osmic mixture for fifteen to thirty minutes. The same 
method answers for Cunina, while Liriope should be treated at once 
with chrom-osmic for five to twenty minutes. 
‚Scyßhomeduse are best fixed with 1 per cent. osmic acid, to the 
action of which they are subjected until they assume a pale brown tint. 
They should then be thoroughly washed with fresh water before being 
placed in 35 per cent. alcohol, and should be finally preserved in 7o 
per cent. 4 
Siphonophores.—The forms of this group should be preserved soon 
after capture, and specimens in good condition should be selected. 
Agalma and similar forms should be killed in the mixture of copper 
sulphate and sublimate, which should be used in volume equal to or 
double that of the sea-water in which the animal floats, The mixture 
should be poured in rapidly, and of over the animal. When killed, 
the specimen should be carefully lifted upon a large horn spatula, and 
transferred to 35 per cent. alcohol for a few hours, and then placed in 
70 per cent. It is recommended to preserve the animals in tubes just 
large enough to contain the specimens and placed within a second lar- 
