266 A. LIVEKSIDGE. 



formed, yielding a violet amorphous powder when dried, insoluble 

 in alcohol and in oil of cloves. 



A similar or the same colouring matter was yielded by a holo- 

 thurian, from the South Indian Ocean ; Moseley regarded it as 

 identical with antedonin. 



Land planarians. — Two large species of Rhynchodemus were 

 found at Parramatta, N.S.W., one red and the other prussian 

 blue. The blue is insoluble in alcohol, and becomes red on adding 

 hydrochloric acid and is soluble in acidified alcohol. 



Mollusca — Aplysiopurpurin. — A purple fluid is emitted by an 

 Aplysia abundant on the shore of St. Vincent, Gape Verde ; the 

 purple fluid is soluble in alcohol. Said to contain aniline. 1 



The purple colouring matter used by the ancients for dyeing 

 linen and woollen, known as punicin, yielded by Purpura capillus 

 and other mollusca, is a colourless secretion which becomes purple 

 on exposure to light. It crystallises readily from its solution in 

 aniline and is insoluble in alcohol and ether. Like indigo it can 

 also be crystallised by sublimation. 



Doris. — A Doris had the surface of the foot coloured a dark 

 purple, the pigment is soluble in alcohol acidified with hydrochloric 

 acid — the spectrum resembles that from Aplysia. 



Ianthinin. — The pigment of the purple fluid emitted by Ianthina 

 was found to be soluble in spirit to a pale pinkish-blue tint, and 

 shows a brilliant red fluorescence like sesculin which is also blue 

 by transmitted light. On adding a drop of hydrochloric acid the 

 colour changes to a clear pale blue — the spectrum is well marked. 

 The pigment is also soluble in glycerin and yields a deep violet 

 coloured solution. The solution in ether resembles that in alcohol; 

 but leaves a residue which dissolves in absolute alcohol to a blue 

 solution. The ianthinin solutions all faded in a week or two. 



Blue Stentorin. — Prof. E. Ray Lankester found that the blue 

 pigment of Stentor cceruleus yields two well marked absorption 



1 See Gmelin, Vol. xvin., p. 422. 



