234 



THE SEA SHORE 



retracted in the dead animals. This is also the case even with living 

 specimens when disturbed or removed from the water ; hence they 

 should always be examined alive in sea water, while the animals 

 are extended and moving. 



It will be understood from the above statements that special 

 methods will be necessary when it is required to preserve specimens 

 for future study, the gills being always retracted when the animal 





FlG. 161. NUDIBRANCHS 



1. Doto eoronata. 2. Elysia viridis. 3. Proctonotus mucroniferui. 

 4. Embletonia pulchra 



is killed for this purpose by any rapid process. We have found two 

 methods, however, that are fairly satisfactory in the majority of 

 instances. Place the living animals in a suitable vessel of sea 

 water, and leave them quite undisturbed till they are fully extended, 

 and then either gradually raise the temperature till they are dead, 

 or introduce into the water, cautiously, a solution of corrosive sub- 

 limate. In the latter case a much larger proportion of the sublimate 

 will be required than when used for a similar purpose with fresh- 



