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■wax, and then dissolved away the shell with acid, and thus got a complete cast 

 of all the excavations which had been made in it. There was one very strik- 

 ing feature present which had not been noticed that evening. There were 

 circular cavities, which in the cast were solid wax. These were irregularly 

 placed, and from one to the other there were connecting tubes, and these 

 knobs in the cast, representing cavities, varying from l-12th to l-8th 

 of an inch in diameter, were very striking, with fine threads of wax from 

 one to the other. 



Dr. Cob bold, referring to the absorption of dentine, stated that there were 

 at the Hunterian Museum two tusks from female Indian elephants, and 

 therefore of small size, which, at the part immediately above the gum, were 

 eroded to the depth of i inch. The question naturally occurred : How were 

 these excavations formed? From their size and other indications, as if 

 chiselled out like the sculptured appearance shown that evening, he had no 

 doubt whatever that they were the result of parasitic erosion. On these 

 tusks were immense numbers of the ova of a Diptei'on — on one tusk, he had 

 counted over 2,000 eggs. A very large proportion of the eggs were broken 

 up and were without the lid. They resembled those of the gadfly's when 

 attached to the hairs of animals. He believed that the maggots had 

 escaped from these egg-shells, and that their presence had caused this erosion. 

 It was quite another question to say by what power the larva produced those 

 excavations. 



The President enquired if the erosions were below the gum If so, the 

 irritation caused b)' disease would set up this appearance. 



Dr. Cobbold replied in the negative. The erosions were on the exposed 

 surface. 



Mr. E. T. Newton said it appeared to him that each of the gentlemen 

 who had spoken, with the exception of Mr. Stewart, had regarded these 

 borings as being the work of only one kind of animal. He thought they 

 might be made by several kinds. Annelids might possibly make such 

 borings, and the vacated burrows might be occupied by sponges, or vice 

 versdi,. As he was anxious to test the question from his own point of view, he 

 had looked over the cases at Jermyn Street Museum, to see what kind of holes 

 were present in the fossil shells, and how far they might be explained by 

 one or other of the theories which had been put forward. He found in the 

 very thick shells, such as Inoceramus, almost globular cavities, always with 

 one aperture in the middle, which apparently opened upon the surface. 

 These cavities were connected together by numerous stolons which much 

 resembled the processes, or pseudopodia, of Foraminifera. If much denuded, 

 as was common in Museum specimens, the casts of these cavities were 

 reduced to a mere knob. In other cases one finds simple isolated cavities, 

 as shown by Mr. Stewart. In one instance a Belemnite was so completely 

 occupied with the casts of fine tubes which had been bored into it that they 

 •might have been taken for a group of Serpulse. Some of these borings 

 might have been made by either Sponge or Annelid ; but he could not con- 

 ceive how an annelid could make the first mentioned cells with the stolons 

 running off from them in every direction, so as to give, in some instances, the 



