m 



MEMORANDA. 



the centre of the coil^ in the same direction, viz., from left to 

 right, for half an horn*, at the expiration of which time I was 



obliged to leave it ; on my return, 

 in about a quarter of an hour, it had 

 v'anished, and could not of course be 

 recognised among its numerous 

 brethren, when uncoiled. 



If I do not err in supposing that 

 a motion of this kind in Oscilla- 

 toria has not been recorded, I beg 

 you will be good enough to '^make 

 a note of it-*^ in your columns for 

 this purpose. 



The filaments of this species are 

 transparent tubes, sparsely studded with small granules, 

 that appear brown, or reddish brown, by transmitted 

 light; their diameter is l-6000th of an inch; the length 

 varies, but amounted in the longest to l-50th of an inch. 

 No markings or segments were visible with Ross's quarter. 

 I did not use any higher power. They were gathered from 

 the bottom of a very muddy pond, nearly dried up, when 

 searching for the "Tank- worm.-" — J. Mitchell, Lieutenant, 

 Madras Veterans. 



On preparing the Shells of the Polycystinae, from Springfield, 

 Barbadoes.— Through the kindness of one of our members. 

 Admiral Duff, I was put in possession of some of the Barbadoes 

 earth from Springfield estate. The shells are in countless 

 multitudes, but imbedded in a light porous substance resemb- 

 ling discoloured chalk. As the shells are known to be sili- 

 ceous, some of the earth was boiled in hydrochloric acid, some 

 m nitric, and some in sulphuric, but no effect was produced. 

 Some was boiled in caustic soda, but the shells dissolved as 

 freely as the matrix. As it is needless to describe numerous 

 failures, I shall proceed at once to the process which succeeded. 



There T^as procured — 



1. A large glass vessel such as gold-fish are put in; 3 or -i 

 quarts of ordinary pipe water were put into this. 



2. A new tin saucepan, holding about a pint. 



3. Two thin precipitating glasses, holding about 10 ounces 

 each. 



Take about 3 ounces of Barbadoes earth (lumps are best), 

 and break them with a piercer into tolerably small fragments. 

 The earth sliould be quite dry. Put 3 or 1 ounces of common 

 ivashing soda into the tin, and half fill the vessel with common 

 water. Set on a clear fire until it boils stron2;lv ; then throw 



