PKOCEEDINGS OK THK M ALACOLOGICAf, SOCIKIT. 



NOTES. 



Note on the occurrence of Pisidium Lilljeborgii in the Isle 

 OF Arran. {Head 8th December, 1911.) — In September, 1911, in Loch 

 Urie, at an elevation of 1,300 feet above Lamlash Bay in the Isle of 

 Arran, many specimens of Pisidium Lilljeborgii were obtained, and some 

 of these were of very large size. Pisidium Lilljeborgii in the above loch 

 is associated with P. Casertanum and P. pusillum. The specimens were 

 identified by Mr. B. B. Woodward. K. H. Jones. 



Note on a large specimen of Anodonta cygnea. {Read 8th 

 December, 1911.) — The average length of adult shells of this species 

 recorded in works on British Mollusca is about 5-6 inches, but examples 

 7i and 9 inches long are mentioned in Mr. Lionel Adams' work. The 

 Collectors Manual of British I^and and Freshwater Shells, 2nd ed., p. 151. 

 The largest of these were taken by Mr. W. H. Heathcote near Preston. 

 The example which I now exhibit, recently acquired by the British 

 ]\Iuseum, was, I am informed by Mr. J. R. Charnley, also taken near 

 Preston by his friend, AV. H. Heathcote. Its measurements are : length 

 8| inches, height 4i\, diam. 3i, girth 1 1|. In the year 1899 Mr. E. R. Sykes 

 presented to the Museum a specimen from Clanghton in Lancashire, 

 7f inches in length, and a specimen in the Cuming Collection, which has 

 been in the I\Iuseum forty-five years, is 85 inches long. Unfortunately no 

 locality was attached to this shell. E. A. Smith. 



Note on Aphanitoma Locardi, Bavay, and Mitba biconica. 

 Sykes. {Read \2th January, 1912.) — In the last part of the "Proceedings" 

 (p. 334), I described a new species under the name of Mitra biconica. 

 Mons. Bavay very kindly wrote to me pointing out the exceeding similarity 

 of this species to his Aplianitoma Locardi^ ; and, having compared my 

 species with his figure and description, I feel no doubt that they arc the 

 same. Whether the form belongs to the Mitridoe or Pleurotomidse, 

 remains to be finally settled ; but it may well prove to belong to 

 Aphanitoma, which genus, hitherto supposed extinct, I had overlooked. 



E. R. Sykes. 



Fragments of Limestone eroded by Helicella caperta. {Read 

 8th December, 1911.) — Specimens were shown that had been picked u]) 

 on a field above Tregeagle Cove, Pendower Beach (between Veryan and 

 Nare Head), South Cornwall, by Mr. C. Davies Sherborn, when on a recent 

 visit to that locality. The limestone was not indigenous, but had beeii 

 brought there and spread as 'dressing' for the soil. The pieces had 

 been sought out by the snails to obtain the lime-salts for their shells, 

 and at the time of their discovery some of the little pits they had eroded 

 were occupied by the excavators. 



The big burrows formed by the larger helicoids have been well known for 

 many years and were correctly described by Dr. Buckland in 1841, but at 

 a later period were assigned by other observers to various agents, including 

 P/iolas, till jMr. J. Rofe in 1870 {Geol. Mag., pp. 4-10) gave an admirable 

 little summary of the whole history and fully re-established Buckland's 

 conclusions. The fact that in districts where there is scarcity of lime in 

 the soil, snails will resoi-t to limestone outcrops, or, as in the Channel 

 Islands, attack the shells of their comrades, seems to show that the 

 animals do not rely on their plant-food solely for their lime-salts, but 

 must get some direct from the soil. B. B. Woodward. 



1 Bull. Mus. Hist. Nat. Paris, vol. xii, p. 548, 190(5. 



