110 PROCEEDINGS OF THE SOCIETY. 



by Mr. Curties, and seconded by Dr. Matthews), and Mr. Curties 

 (proposed by Mr. Guimaraens, and seconded by Mr. Michael), were 

 duly elected. 



Mr. Stewart gave a resume of a paper by Mr. W. J. Sollas, M.A., 

 F.G.S., " Observations on Dacti/localyx pumiceus (Stuchbury), with de- 

 scription of a new variety, D. Stucliburyi" the chief points of interest 

 in which were illustrated by diagrams drawn ujjon the black-board. 

 The photographs and drawings which accompanied the paj)er were 

 also handed round for inspection, (This paper will appear in the 

 April number.) 



Dr. Matthews said that he had been giving a good deal of atten- 

 tion lately to the subject of corals, madrej)ores and allied forms, and 

 on examining them he thought he had found some evidences of para- 

 sitism. At the base of each of many specimens, he had found that 

 there was a rough mass of stony material which he at first cast aside. 

 Some time afterwards he was led to examine these parts in the hope 

 of finding diatoms or foraminifera uj^on or in them, and he then dis- 

 covered the curious fact that each coral was more or less based upon 

 a sjjonge, and that it appeared to be a real case of parasitisai. He at 

 first thought that he had made a discovery, but further inquiry showed 

 that there had been a paper written upon the subject by Mr, Carter.* 

 He (Dr. Matthews) found that this state of things was shown in nine 

 cases out of ten of the sj)ecimens examined by him. There were, 

 however, some other specimens which displayed clear evidence of 

 having been bored by a sponge. He had also found that certain 

 sponges had become associated with some of the madrej^ores in such 

 a manner, as to suggest the idea of a kind of mutual parasitism or 

 commensalism, and also that in some cases the whole sponge had 

 become enclosed and the cavity filled by sarcode and gemmules, the 

 whole being fused together in such a way that it was hardly possible 

 to tell by the Microscope where the gemmules ended and the corallum 

 began ; in fact, the fusion of the two seemed very complete and extra- 

 ordinary, the thin layer of corallum extending completely over the 

 sponge. He had found also some foraminifera, but had not yet had 

 time to examine them. Mr. Carter in his paper did not mention any 

 coral larger in size than \ inch, and this was described as being wholly 

 on the surface of the sponge. He thought the matter was worth 

 mentioning, and although it might be only one fact added to the great 

 heaj), it might some day be of use when clealt with by other hands. 



Mr. Stewart said that very commonly before these corals arose as 

 a branching stem they spread out in a thin layer, from which the 

 corallum afterwards arose. They were very often fixed to a loose 

 kind of oolitic rock, which was very friable and easily broken down, 

 and it was easy to imagine how this kind of cap might involve a 

 sponge. If what had been described occurred in this manner, he 

 should hardly be disposed to call it a case of parasitism. In some 

 kinds, however, such as the Hyalonema or glass rope sponge, they 

 * See vol. i. p. 288. 



