. 862 The American Naturalist. [September, 
ger tube. In this way evaporation of the alcohol is prevented, and 
also injury of the specimen from movements of the liquid is avoided. 
Physalia should be placed in a cylinder filled with sea-water, the 
animal being lifted by the pneumatophore. When well expanded it is 
killed by pouring over it the sublimate and acetic acid mixture (one- 
quarter the volume of the sea-water), and when dead is transferred to 
a cylinder containing one-half per cent. chromic acid, and then after 
twenty minutes to 50 per cent. alcohol, and finally to 70 per cent. 
Velella may be killed with chrom-picric or sublimate and chromic 
acid mixture, and after a few minutes should be transferred to weak al- 
cohol. Porpita may be fixed by dropping Klienenberg’s picro-sul- 
phuric acid into the vessel in which it is contained, and when the blue 
color commences to change to red it should be transferred to Kleinen- 
berg’s fluid, and after fifteen minutes to weak alcohol. 
Diphyes may be killed expanded by hot corrosive sublimate. 
Ctenophora may be killed by throwing them into the chrom-osmic 
mixture, where they should remain for fifteen to sixteen minutes, 
according to the size, and then gradually passing them i alcohol 
to 70 percent. A mixture composed of 
Pyroligneous acid, concentrated, . ........ I vol. 
Corrosive sublimate solulo, . . < n.. «+. << 2 vols. 
neba Der Cont. Chrome dd o . . . ... ss ı vol. 
is also recommended as a fixative. 
Echinodermata.—Starfish may be prepared with the ambulacral feet 
in full distension by allowing them to die in 20 to 30 per cent. alcohol. 
Echinoids should be placed in a small quantity of water, and killed 
with chrom-acetic mixture No. 2, being removed from it as quickly as 
possible, as the acid corrodes the test. To preserve the internal parts 
it is necessary to make two opposite openings in the test, so that the 
alcohol may penetrate the interior readily. 
Holothurians, such as Zhyone and Cucumaria, after the tentacles are 
fully expanded, should be seized a little below the bases of the tenta- 
cles by forceps, using a slight pressure, and the anterior portion of the 
body should then be immersed in concentrated acetic acid. Alcohol 
(90 per cent.) should then be injected into the mouth, and the speci- 
mens placed in 70 per cent. alcohol. The injection should be repeated 
each time the alcohol is changed. 
Synapta should be fixed by immersion in a tube containing a mixture 
of equal parts of sea-water and ether (or chloroform), where they re- 
main completely expanded. They should then be washed for a short 
