cent chromic acid, where they are allowed to rest at least half 

 an hour. Then after thorough washing in fresh water, they are 

 put into alcohol of 70 per cent, and afterwards into that of 90 

 per cent. Spirographis can not be well treated in its tube or 

 be returned to it after treatment. Myxicola infundibulum is kill- 

 ed in saturated sublimate, and, after ten or fifteen minutes, 

 thoroughly washed and put into 50 per cent alcohol for a few hours 

 before it is put permanently into that of 70 per cent. 



The following annelids are killed with cold saturated sub- 

 limate, in which they should not be allowed to remain more than 

 fifteen minutes; all the Amphictenidae (which may be placed in 

 alcoholized sea water until well out of their tubes) , the Hermelli* 

 dae, the Serpulidae (some of which should remain for some hours 

 in a 0.1 per cent solution of chloral, so that they may come 

 wholly or partly out of their tubes) , of the Aphroditidae certain 

 Polynoinae, Polyodontes maxillosus, of the Eunicidae all the group 

 of the Eunicinae. Some of these, like Dioptara, are best fixed 

 by narcotizing them in alcoholized sea water. 



Alciopidae are very well prepared by letting them die in 

 the sulphate of copper and sublimate mixture. They should remain 

 in the solution not to exceed five minutes, and then be washed 

 thoroughly in fresh water before they are placed in alcohol. 



Tomopteridae are preserved in the way just described, or 

 with cold saturated sublimate. Remove the last traces of sub- 

 limate with iodine. 



Crustacea 



The marine Cladocera (Podon, Evadne) are killed with satu- 

 rated sublimate, or with a few drops of osmic acid of 1 per cent 

 in the sea water containing them, removing them when they begin 

 to turn brown. Wash and put into 70 per cent alcohol. 



Ostracoda are put at once into 70 per cent alcohol. 



Copepoda. — The free forms are killed in a saturated solu- 

 tion of sublimate in sea water, where they are allowed to stay 

 from five to ten minutes. The parasitic forms may be killed in 

 the same way or be put at once into weak alcohol. 



Cirripedia. — To prepare Lepas, Conchoderma, etc. with 

 the cirrhi distended, let them die in alcohol of 35 per cent. 

 If the cirrhi of certain species contract they can easily be 

 drawn out again by means of forceps. 



Balanus and similar forms are immersed directly in alcohol 

 of 70 per cent, taking care to change the liguid soon. 



Rhizocephala (Sacculina, Peltogaster, etc.) are placed for 

 fifteen minutes in a mixture of 90 per cent alcohol and sublimate 



- 40 - 



