Page:Quarterly Journal of the Geological Society of London, vol. 27.djvu/54

 pebbles in gravels within the Wealden area, and the manner in which the transverse valleys open out, estuary-shaped, into the Weald, he infers that that was occupied in Postglacial times by an inlet of the sea, into which rivers flowed from the Thames-valley area, and that the denudation was chiefly effected by tidal erosion during a gradual upheaval of the land.

The Rev. John Gunn is now of opinion that the "Forest-bed series," which he has so long and carefully studied, is older than the Norwich Crag and the Chillesford Clays, and that the latter covers both the other deposits transgressively in proceeding from the coast toward the interior of the country.

Mr. Ray Lankester has made further contributions to our knowledge of the Crag-beds of Norfolk and Suffolk. He considers that the Stone-bed at the base of the Norwich Crag is not identical with the Bone-bed at the base of the Suffolk Crag, and shows the marked difference in their mammalian fauna. The Rhinoceros, Tapir, Hipparion, and Hyaena of the Bone-bed are introduced Miocene species ; while the Elephants and Deer of the Stone-bed and Forest- bed are of Pliocene species not found in the Bone-bed. He describes from this latter bed a new ziphioid cetacean, and has determined the presence of Mastodon arvernensis in a sandstone nodule found in it. Of these nodules Mr. Lankester gave additional particulars, showing, by their organic remains, their derivation from beds of " Diestien " age.

In making excavations for the extension of the dockyard in Portsmouth Harbour, a fine section of the Lower part of the London Clay, with overlying gravel and alluvial beds, has been exposed ; and a good account has been given of them by Mr. C. J. A. Meyer. Some of the beds are very fossiliferous, and contain an assemblage of species which have not been found elsewhere in the London Clay : one of the species is a Thanet-sand form, while another is the well-known Cardita planicosta of the Bracklesham beds and of the Calcaire grossier.

Secondary Formations.

The only communications we have had on the Cretaceous series are as follows. Mr. Whitaker describes the divisions of the Chalk of the south coast. He shows that the Chalk Marl and Lower Chalk thin westwards, while the Upper Chalk with flints passes transgressively over and beyond it, and thus are flints found so far west. Mr. Judd gives the result of his further examination of the Neoco-