Abstract
LONDON.
Geological Society, May 2.Dr. Alfred Harker, president, in the chair.Jane Longstaff (née Donald): Sup- pletnentary notes on Aclisina, De Koninck, and Aclisoides, Donald, with descriptions of new species. Since the publicatiQn of a paper by the Geological Society on Aclisina in 1898, knowledge has been gained of the species there described, and six others new to science have been discovered. The diagnoses of tlese are given. The total number of species of Aclisina is brouht up to twenty-two. The genus is best represented in Scotland, where the specimens are generally well preserved. A table is appended giving the range and localities in the British Isles and Belgium, A small variety of Aclisina ulchra, De Koninck, appears. to have continued for the greateSt. length of time. Additional observations are also made on A cli- soides, striatuict, De Koninck.T. H. Burton: The microscopic material of the Bunter pebble-beds of Nottinghamshire and its probable source of origin. As shown by th distribution of the heavy minerals, combined with (a) tne direction of the dip in the cross- bedding, (b) the evidence adduced by boreholes and shaft-sinkings, a main current from the west is indicated. A large quantity of the material is derived from metamcrphic areas. The source of the bulk of the material is probably Scotland, and the westward adjoining vanished land, from rocks similar in the main to those of the metamorphic and Torridonian areas known in that tountry. The material was transmitted by means of a north-western river and its tributaries, flowing ito the Northern Bunter basin. During certain flood-periods this river overflowed across Derbyshire, carrying its load of sediment, much of which was deposited in the pebble-beds of Nottingham- shire.
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Societies and Academies . Nature 99, 238–240 (1917). https://doi.org/10.1038/099238b0
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DOI: https://doi.org/10.1038/099238b0