Some ten years ago Mr. Alfred Gillett observed in a quarry of the Lower Lias near his residence at Overleigh, Street, Somerset, a number of broken slabs of shaly limestone, containing portions of the skeleton of an Ichthyosaur. These slabs, which had been cast aside by the workmen, were fitted together by Mr. Gillett, who finally succeeded, after the expenditure of great pains, in skilfully developing from them an almost entire example of the skeleton of Ichthyosaurus tenuirostris, Conybeare.