BY R. VON LENDENFELD, PH.D. 669 



found that the paper, after a day or two, is stained a deep violet 

 blue. A colour which will not disappear when the paper is 

 washed with water or ether. Concentrated acids and strong 

 alkalis affect the colour. Acids make it red like litmus. Alkalis 

 turn the red colour blue again. 



I do not know anything about the chemical nature of the colour. 

 It is very remarkable that the spirits are only stained light yellow 

 by the sponge. It appears that the colour is precipitated on the 

 paper, &c., after it has been extracted fi'om the sponge by the 

 spirits. 



It appears that a great quantity of paper, &c., can be stained 

 by a very small piece of the sponge, and I think that possibly 

 this discovery might be turned to practical account for the purpose 

 of dyeing blue-violet. 



IV. TWO CASES OF MIMICRY IN 

 SPONGES. 



In the cases in question two species of horny sponges imitate 

 two species of Siliceous sponges. As both the two imitating and 

 also the two imitated sponges are new species, it will be necessary 

 to give a short description of them first. 



GENUS. CHALINOPSIS. 



Sponges which belong to the family Spongidte, sub-family 

 Chalinopsinae which imitate the shape of Chalinidge, more or less 

 closely, and which have a light and tender skeleton composed of 

 radial main and tangental connecting fibres without conuli and 

 without vestibule spaces. The skeleton is more or less grey in 

 the dry state. Sponges of digitate shape. 



CHALINOPSIS IMITANS. Nova species. 

 Digitate processes regular smooth and cylindrical, very long and 

 slender, slightly branched. Oscula very small. Digitate pro- 

 cesses tapering to a more or less sharp point. The sponge is 

 attached by a short thick stem. 



