266 



ON THE DETERIORATION OF SHELLS IN CABINETS. 



By AGNES F. KENYON. 



(Read before the Society, September nth, 1907). 



This subject will be best divided, and 1 will take first the effects of 

 dampness or humidity in the atmosphere. The deplorable effects 

 produced by this cause in a collection are liappily of infrequent 

 occurrence, and the only two instances of which I am aware are both 

 Australian. The first case happened in my own collection, and until 

 this experience befel me, I think I should have deemed it a matter 

 of impossibility for a shell to lose its colour as mine did. I had in 

 my possession for some years a young example of Cyprcea aurantiiDii 

 Mart., of very thin, almost transparent, fabric and of a matchless deep 

 red colour. I believe that the only other young example known of 

 this species is in the British Museum. For five or six years the 

 lovely tint of my Cyprcta was quite unaltered, when unfortunately I 

 went for a month's holiday to Tasmania. During my absence my 

 next-door neighbour started trenching his garden to a depth of several 

 feet, and in order to soften the hard earth kept the water-pipes 

 running and saturated the ground. Of course in a warm climate the 

 walls of a house are not particularly thick, nor are the foundations 

 deep, and I have no doubt whatever that the aqueous vapour pene- 

 trated through the foundations of our house and imperceptibly but 

 surely permeated the atmosphere. Anyhow the lovely red colour of 

 my C. aurantiiun faded into a lemon-yellow in the space of four 

 weeks, though the polish of the shell remains as brilliant as before. I 

 cannot imagine any cause for this speedy change except damp. 



I have also seen a more recent instance of the effect of damp on a 

 collection of shells, though the results were somewhat different to 

 those in my experience. The collector required a larger space for 

 his cabinets, corals, etc., and built a separate museum-room, enclosing 

 therein an ornamental rockery where plants had been growing in 

 tanks of water. I noticed, when examining his collection, that some 

 of the larger specimens of Cyprcea had the dorsal surface partly or 

 wholly clouded over with a whitish lime-like film, and on enquiry 

 learnt that this had taken place since the cases had been lodged over 

 the old water-tanks. As far as I recollect the species affected were 

 C. argils, C. cervus, C. maurituiiia, C. teshuiinaria and others: the 

 different effect produced may have been due to their mature condition, 

 and the consequent thickness of the enamel. 



