528 Transactions of the Society. 



10 p.c. formaldehyde. Cork down tightly, and the specimens will 

 require no further attention, and are ready at any time for 

 examination. 



The larvge of Echinodermata require special care, as it is 

 important to preserve the calcareous skeleton intact. Pluteus, 

 Auricularia, and Bipinnaria are best killed and fixed by placing in 

 a cold saturated solution of corrosive sublimate, in which the}'^ 

 should not remain longer than four minutes. They must then be 

 carefully and thoroughly washed with water and transferred to a 

 dilute cochineal stain only just possessing a perceptible tinge of 

 colour. Mayer's old alcoholic cochineal formula certainly gives 

 the best results, and is prepared as follows : " Cochineal in coarse 

 powder is macerated for several days in alcohol of 70 p.c. For 

 each gramme of the cochineal there is required 8 to 10 c.cm. of the 

 alcohol. Stir frequently. Filter, and the I'esulting clear, deep red 

 solution is fit for staining." For staining the Echinoderm larvae 

 it must be further diluted with 70 p.c. alcohol, until only a trace 

 of colour sliows. The larvae may be left in the dilute stain for 

 twelve to twenty-four hours, and then passed through graded 

 alcohols, cleared in oil of cloves or oil of cedar-wood, and mounted 

 in balsam. Mayer's alcoholic cochineal is a very useful stain for 

 many marine organisms, and provided the specimen has not a 

 delicate calcareous skeleton, any overstaining may be reduced by 

 washing in 70 p.c. alcohol, containing ^ p.c. hydrochloric acid, or 

 1 p.c. acetic acid. 



Small sponges collected in the rock-pools I place at once into 

 1 p.c. solution of osmic acid, in which they remain for about five 

 minutes, and are then placed in strong alcohol, which should be 

 changed twice. Sections stain well in Mayer's alcoholic cochineal. 

 Young Sycones may be fixed in absolute alcohol and stained with 

 alcoholic carmin. For the larvae of Spongilla I have always found 

 the method used by Delage to give very good results. The larvae 

 are allowed to settle down on a large cover-glass, and are then 

 fixed for three minutes in absolute alcohol. They are then stained 

 in alcoholic carmin, passed through graded alcohols, cleaned in oil 

 of bergamot, and mounted in balsam. 



Anemones, Corals, Alcyonium and Gorgonia are all difficult 

 animals to preserve in an extended condition. I think the best 

 results I have so far obtained are by first narcotizing with 

 menthol, which may take from twelve to twenty-four hours. Sea 

 anemones are then plunged into formalin or formalin-alcohol, in 

 which they are best preserved. Alcyonium and Gorgonia are plunged 

 into hot corrosive sublimate, washed in 70 p.c. alcohol, and stored 

 in 75 to 80 p.c. alcohol. 



Holothurians I narcotize with menthol, transfer to 70 p.c. 

 alcohol, and at the same time inject 90 p.c. alcohol through the 

 anus. Store in 70 p.c. alcohol. 



