HICKS, HENRY , Welsh physician and geologist, was born on May 26, 1837 at St. David's, in Pembrokeshire, where his father, Thomas Hicks, was a surgeon. He studied medi cine at Guy's Hospital, London, and practised in his native place until 1871; when he removed to Hendon, where he died on Nov. 18, 1899. In conjunction with Salter, he established in 1865 the Menevian group (Middle Cambrian) characterized by the trilobite Paradoxides. Subsequently Hicks contributed a series of impor tant papers on the Cambrian and Lower Silurian rocks, and fig ured and described many new species of fossils. Later he worked at the Pre-Cambrian rocks of St. David's, describing the Dime tian (granitoid rock) and the Pebidian (volcanic series), and his views, though contested, have been generally accepted. At Hen don Dr. Hicks gave much attention to the local geology and also to the Pleistocene deposits of the Denbighshire caves. He de tected organic remains in the Morte slates, previously regarded as unfossiliferous, and these he regarded as including representa tives of Lower Devonian and Silurian. His papers appeared in the Geol. Mag. and Quart. Journ. Geol. Soc. He was elected F.R.S. in 1885, and president of the Geological Society of Lon don (1896-98).