phorus) , after they have been narcotized in a 0.1 of 1 per cent 

 solution, may well be placed for some hours in a 0.2 of 1 per 

 cent solution before they are killed. 



The larval form, Pilidium, is killed either with the 

 sulphate of copper and sublimate mixture or with saturated sub- 

 limate alone. 



The Nematodes, free and parasitic, are killed with saturat- 

 ed sublimate or with Kleinenberg ' s liquid. 



Chaetognatha. — These are very well treated in the mixture 

 of sulphate of copper and sublimate and in the chrom-osmic mix- 

 ture. 



Gephyrea — Sipunculus is killed with chromic acid of one- 

 half of 1 per cent or even weaker, in which the tentacles usually, 

 but not always, expand before death. The animal, after being 

 narcotized with chloral hydrate of 0.1 of 1 per cent in sea water, 

 dies with tentacles distended. Both methods are good, but some- 

 times a portion of the animal remains contracted, and sometimes 

 during the process the skin in front breaks and allows all the 

 perivisceral liquid to escape, with resulting distortion of the 

 body. 



Phascolosoma may be placed in alcoholized sea water and 

 allowed to remain there until dead (three to six hours) . Phoronis 

 is allowed to remain half an hour in alcoholized sea water and 

 then is killed with boiling saturated sublimate. With the large 

 specimens of Bonellia it is best to wait until the proboscis has 

 become well distended and then seize the body of the animal with 

 one hand and the extremity of the proboscis with a pair of forceps 

 so that it can be kept distended. Then quickly immerse the whole 

 in Kleinenberg ' s liquid in the wax -bottomed tray, and, always keep- 

 ing the animal stretched out to prevent contraction, wait until 

 it dies. After lying for an hour in this solution the transfer 

 to alcohol may begin. Small Bonellias are narcotized in alcohol- 

 ized sea water and fixed in weak alcohol. The very small speci- 

 mens of these Gephyreans are very well killed with hot sublimate. 

 The pelagic larvae of Echiurus are well fixed by allowing them 

 to lie for some minutes in the mixture of sulphate of copper and 

 sublimate. 



Hirudinei, Pontobdella, and Branchellion are killed in 

 chromic acid of one-half of 1 per cent. If in doubt about worms 

 of this family, hot saturated sublimate may be recommended for 

 use. In any case long specimens must be straightened and hardened 

 in the wax-bottomed tray. 



Chaetopoda. — Many of these, if placed in a fixing fluid 

 which is too energetic in action, contract greatly and twist out 

 of shape, and many of them break to pieces, so that an idea of 

 the natural form is lost. This trouble has been obviated by very 

 gradually pouring over the surface of the sea water in the crystal- 



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