118 methods oe collecting and preserving 
PoLYZOA. 
Polyzoa are horny, calcareous, or gelatinous; they incrust other 
objects, or form masses or arborescent growths. They are nearly 
all colonial animals, and usually the small separate “zooecia” can 
be made out with the naked eye or with a lens. Polyzoa are mostly 
marine ; bnt there are also a number of fresh-water species. 
These animals may be preserved in strong spirit or in 10 per cent, 
solution of formalin. 
Specimens can be obtained with polyps expanded by killing sud¬ 
denly with warm corrosive sublimate animals with polyps already 
expanded; or narcotization with chloral hydrate or alcohol may be 
resorted to. 
Brachiopoda. 
Signor Lo Bianco recommends narcotizing in alcoholized sea-water. 
Before placing in alcohol for final preservation, a small chip of wood 
is placed between the valves of the shell. Without this precaution 
sea-water will be retained between the shut valves, and the soft 
parts will putrefy. 
Tunicata. 
The minute tailed Ascidians, known as Appendicular ice, sometimes 
occur in abundance at the surface of the sea. Signor Lo Bianco 
recommends that they be killed by leaving them for five minutes 
in a mixture of chrom-osmic acid (see “ Ctenophora ”) ; they are 
then washed and graded (see p. 97) in alcohol. 
The pelagic Tunicata (Pyrosoma, Salpa, Doliolum ) are killed and 
fixed with osmic acid, washed in fresh-water, and transferred to 
strong spirit or 10 per cent, formalin. 
Simple and compound Ascidians should be narcotized by placing 
them for some hours in chloralized sea-water containing hydrate of 
chloral 1 in 1,000. They may then be put into strong spirit or 10 
per cent, formalin, which should be changed after twenty-four 
hours, because Ascidians contain much water. 
Mr. A. B. Lee* strongly recommends for Compound Ascidians a 
* A. B. Lee, “ Microtomist’s Vade Mecam, - ’ 5th edit., 1900, p. 460. 
