lis METHODS or 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 ; but there are also a number of fresh-water species. 



These animals may be preserved in strong spirit or in 10 per cent, 

 sokition 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. 



SignorLo 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 w411 putrefy. 



TUNICATA. I^B 



The minute tailed Ascidians, known as A2)pendicula7'i(e, 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 (sea p. 97) in alcohol. 



The pelagic Tunicata {Fyrosoma, 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. 41)0. 



