308 NATURAL HISTORY OP OUR SHORES 



Chrysaora, etc. etc. that were so difficult to preserve 

 formerly, having to be treated with osmic, chromic, etc., 

 before being put into spirit, can now. thanks to formalin, 

 be preserved right away in this medium, and make very 

 good preparations. The large ones must be suspended by 

 a thread, well centred, this thread attached to a cross one 

 fixed just under the stopper of the jar. 



The Echinoderms. These, with the exception of the 

 Holothurians and the Feather Star (Antedon), are usually 

 put up dry. Many species e.g. the common " Brittle 

 Star," and one or two more often break off their arms in 

 course of collecting or subsequent manipulation. It is a 

 good plan to drop these right into spirit as they are caught. 

 Some plunge them into fresh water, which also often kills 

 them quickly, without damage, but spirit is the best. 

 After killing they must be rinsed in fresh water, to remove 

 the salt, and then in a weak solution of corrosive, after 

 which they can be set out with pins into position on a 

 board, and left to dry, when they can be transferred to the 

 cabinet drawer or, temporarily, card boxes. A thread 

 passed over them and through the bottom of the box will 

 keep them steady and prevent breakage. 



The larger star-fishes, Uraster, etc. etc., can be treated 

 in the same simple way, although some insist on the neces- 

 sity of cleaning them out by the mouth, with a hooked 

 wire, and stuffing with cotton wool. In Solaster, which 

 sometimes loses its convexity in drying, I have found 

 this necessary, but a good soaking in corrosive and a 

 thorough drying are important. A soaking for a few days in 

 a suitable vessel with methylated spirit and corrosive is 

 very good ; the drying is then more rapid, and the preserva- 

 tion permanent. 



The strength of the corrosive should be such that it will 

 not dry as a white powder on the surface. The strength 

 can be tested by dipping a black feather in it and allowing 



