VII. On beds of sponge-remains in the lower and upper greensand of the South of England

Abstract

In the course of a search for fossil sponges in the lower cretaceous deposits of the South of England, I have noticed the occurrence at different horizons of beds of rock, of not inconsiderable thickness, composed to a large extent of the spicular remains of sponges. The strata in which these remains occur are well known, and they have been described in numerous papers from the date of Dr. Fitton’s celebrated memoir of “The Strata between the Chalk and Oxford Oolite," in 1827, to the present time, but owing probably to the microscopic dimensions of the remains, and the various changes in their fossilisation which have oftentimes rendered them unrecognisable to ordinary observation, the# organic character of the strata has been seldom recognised, and only in one or two cases have their contents been noticed in detail.