98 The Irish Naf?(ralisf. [April, 



PROCEEDINGS OF IRISH SOCIETIES. 



RoYAi, Zooi.oGiCAiv Society. 

 Recent gifts include a pair of Black-headed Gulls from Dr. C. J. Patten, 

 a Monkey from Mr. T. Broome, and a Barn Owl from Mr. A. Thomson. 

 3,646 persons visited the Gardens in February. 



Dublin Microscopic.\Tv Club, 



January 18. —The Club met at Leinster House, Mr. Greenwood 

 PiM in the chair. It was announced that Mr. Andrews wished to resign 

 the presidency of the Club, and Mr. Pirn was unaniiuously elected to the 

 vacant office. Dr. J. A. Scott was appointed Vice-President, Mr. F. W. 

 Moore, Hon. Secretary, and Mr. \V. N. Allen, Hon. Treasurer. Some 

 proposed alterations in the rules were discussed, and a decision thereon 

 postponed until the next meeting. 



Prof. T. Johnson exhibited a preparation of a sclerotium of the 

 fungus Sclerotinia sclerotiorum, taken from a diseased Jerusalem artichoke,^ 

 grown at Greystones, from " seed" imported from England two years in 

 succession and each year increasingly diseased. The disease is due to 

 the same fungus as that which helps to cause the 3'ellow-blight in 

 potato-plants in the west and other parts of Ireland. The material was- 

 received from Miss Hughes. 



Mr. Henry J. Seymour showed photo-micrographs of rock- 

 sections, and also a thin section of a peculiar silicified limestone from 

 Slane, Co. Meath. This rock was originally a fossiliferous and oolitic 

 limestone of Carboniferous age, and contained some minute quartz- 

 granules. Subsequently the carbonate was almost entirely dissolved away 

 and replaced by secondary silica, which has grown in optical continuity 

 around the original quartz-granules as a nucleus. The result has been 

 the formation of a mesh-work of interlacing acicular crystals of quartz, 

 many of which are bi-pyramidal. So gradual has been the replacement, 

 of the calcium carbonate, that the concentric rings of the " oolite" are 

 perfectly preserved as pseudomorphs in silica, and may be seen passing 

 through as many as five or six independent quartz crystals. 



Mr. J. N. HalberT exhibited living examples of the '* Mud Mite," 

 Limnochares holosen'cea, Lat. In its structure and habits this species forms 

 a connecting link between the true water mites (^HydrachnidcR) and the 

 land mites (7>i?W(^/fl^/«/w, &c.). Only the one species is known, which is 

 not uncommon at the bottom of pools and semi-stagnant water in the 

 neighbourhood of Dublin. 



February 15. — The Club met at Leinster House. 



Mr. Greenwood Pim, President, showed a very curious mould, 

 Botryiis dichotoina. The specimen which had been in his possession since 

 1874 was mounted dry, and was in perfect preservation. It consisted of 

 rather thick hyphae, branched dichotomously, and covered with spherical 

 spores, each suppvorted on a short pedicel, resembling very short, round- 

 headed pins. It occurred on a decaying stem in Mr. Pim's garden, and 

 does not seem to have been found in the British Isles either before or 



