400 The American Naturalist. [April, 
able one to obtain the desired results and in a much simpler manner 
than that described by Tullberg. Complete stupification of the organ- 
ism must be produced, so that when it is removed to a killing fluid, no 
contraction will take place. Care should be exercised, however, not 
to carry on the process too slowly as maceration may ensue. 
Ca@LENTERATES.—The most beautiful results were obtained with sea- 
anemones which ordinarily are so difficult to preserve in a well expanded 
condition. These were allowed to expand in a dish with as little water 
as possible. Then crystals of magnesium sulphate were placed in the 
bottom of the dish and allowed to dissolve slowly until a saturated solu- 
tion was obtained. The process of dissolving may be hastened if neces- 
sary by stirring up the water gently from time to time with a pipette. 
Several hours were required to completely stupify large specimens. 
When narcotization was complete, a few crystals placed in the mouth of 
the sea-anemone had no effect but if the process had not gone far enough 
the lips of the animal would slowly spread open and then would follow 
sometimes a violent contraction of the whole animal. This method 
was tried upon Metridium marginatum, Sagartia leucolena and Halo- 
campa producta with excellent results, the tentacles remaining perfectly 
expanded after the animals had been transferred to Perenyi’s fluid, 
picro-sulphuric acid or formalin. The same method applied to Astr- 
angea, Seyphistoma, and various hydroids did| not give as good results 
as those obtained with the sea-anemones. The polyps were not equally 
affected so that only portions of the colonies were perfectly expanded. 
A large Physalia treated in this way was preserved in 4% formalin 
with all the tentacles and polyps fully extended. _ 
ECHINODERMS.—Star-fishes and sea-urchins were killed with the am- 
bulacral feet and pedicellaria well extended, by placing them upon the 
aboral surface for a short time in a saturated solution of Epsom salts 
and then transferring them to 4% formalin. The epidermis of the 
star-fishes, however, was rendered soft and was subsequently easily rub- 
bed off, but this was probably due to the formalin. 
Specimens of Synapta were readily preserved without any constric- 
tion by very slowly and intermittently adding to the water, in which 
they had been allowed to expand, a saturated solution of MgSO,,. 
VerMes.—Most annelids when placed in a saturated solution of 
Epsom salts, in a very short time became perfectly limp and were 
easily extended upon a glass plate and treated with a fixing reagent. 
Balanoglossus, when taken soon after being collected, was preserved in 
this manner in nearly a perfect state. It was necessary, however, to 
keep it in position between the edges of two glass slides when the fix- 
