860 The American Naturalist. [September, 
Sponges.—Direct immersion in 7o per cent. alcohol, with subsequent 
renewal of the fluid, is recommended for the majority of forms. To 
avoid contraction in the case of the Halisarcidz they should be left for 
half an hour in 1 per cent. chromic acid, or in concentrated solution 
of corrosive sublimate for fifteen minutes, To prepare dried specimens 
the sponges should be washed in fresh water for a few hours, and then 
allowed to remain in ordinary alcohol for a day, after which they may 
be dried in the sun. 
_ Anthozoa.—The first care must be to place the forms belonging to 
this group in fresh salt-water, to allow them to expand, a result which 
may not be obtained until the following day in some cases. Alcyon- 
arians should be killed with chrom-acetic solution No. 2, withdrawing 
the water in which they lie until there is left just enough to cover them, 
and then adding a volume of the chrom-acetic solution double that of 
the sea-water. The animals should be removed from this mixture the 
moment they are killed, since the acid will quickly attack the caica- 
reous spicules, which are important for the identification of the Alcron- 
aria, and placed in 35 per cent. or 50 per cent. alcohol, it being well 
to inject the alcohol into the mouths of the polyps to keep them freely’ 
expanded. s preparation should finally be preserved in 70 per cent. 
alcohol. 
Regarding the Actinians no definite rule for preservation can be 
given. Much of the success of the preparation depends on tle form 
. employed, some species contracting much less readily and less yerfectly 
than others. Some may be killed in a fair condition by pounng over 
them when expanded boiling corrosive sublimate, and then, before con- 
signing them to alcohol, treating for a few minutes with one-half per 
cent. chromic acid. This method may be employed with small forms 
such as 4z/Zasia. Narcotization may be tried with others. For this 
purpose remove from the vessel in which the animals ar: contained 
two-thirds of the sea-water, and replace it with a 2 per cent. solution 
of choral hydrate. After a few minutes the fluid is agzin removed, 
and cold concentrated sublimate solution is poured, i5. Tobacco 
smoke, in some cases, as with Adamsia, will act satisfastorily, if fol- 
lowed with vapor of chloroform for two to three hours, :fter which the 
animals may be killed in chrom-acetic, solution No. 2 and hardened 
in one-half per cent. chromic acid. 
Edwardsia may be narcotized by gradually adding 70 per cent. al- 
cohol to the sea-water in which they are, and subsequently may be. 
killed with hot corrosive sublimate. 
