PEOCEEDTITGS OF GEOLOGICAL SOCIETIES. 



267 



In the first part of this paper the author described certain outliers of 

 Tertiary strata in the neighbourhood of Bedwin and Savernake (or Marl- 

 borough) Forest, in Wiltshire, where in the course of the Geological Survey 

 of the district he found that both the Woolwich and Heading beds and the 

 London Clay gradually thinned out westward, until merel}^ 3 or 4 inches 

 of the latter alone remained between the Bagshot beds and the Chalk. 

 Further eastward these are probably in direct apposition. The superficial 

 loam and clay with unworn flints of the Chalk district along the northern 

 side of the London Basin were then described. 



In the second portion of the paper it was shown, both from the published 

 results of Mr. Prestwich's researches and later observations made in the pro- 

 gress of the Geological Survey, that the Thanet Sands thin out westwardly, 

 from a thickness of about 85 feet in the Isle of Thanet, to about 35 feet at 

 London, and to 3 feet at Chobham, disappearing altogether near Epsom. 

 The Woolwich and Heading beds include the Blackheath Pebble-bed, ac- 

 cording to the author : at Herne Bay Mr. Whitaker gives these beds a 

 thickness of about 50 feet, at Croydon 45 feet, at New Cross 54 feet, at 

 London from 40 to 70 feet, at Ealing 60 feet, at Hanwell 75 feet, at Chis- 

 wick 90, at Heading about 50 feet, and near Great Bedwin, in Wiltshire, 

 only 15 feet. The London Clay, with its basement-bed, is nearly 480 feet 

 thick at Sheppey, 400 feet at London, 370 feet at Heading, 20 to 60 feet 

 near J^ewbury, only 15 feet near Great Bedwin, and is represented by a 

 few inches of its pebbly basement-bed in Marlborough Forest. 



The third part of the paper treated of the Grey wether Stones of Wilt- 

 shire, which the author believes must have come from the Bagshot Sand, 

 which alone of the Tertiary beds is present there in sufficient thickness to 

 3deld these large and numerous masses of bedded rock. 



3. " On a Clay-deposit with Insects, Leaves, etc., near Ulverston." By 

 John Bolton, Esq. 



The deposit described in this paper was a greenish-drab clay, lying be- 

 neath a capping of locally derived drift and rubble of varying thickness, 

 upon the Mountain-lhnestones of Low Furness. It was met with during 

 the progress of drainage-works undertaken by the Lindal-Cote Iron-ore 

 Company. At one locality, the clay is 93 feet from the surface, and has 

 a thickness of 15 feet ; it seems to fill a basin in the limestone. The im- 

 bedded plant- and insect-remains and its contained Diatomacese proved 

 the deposit to be of lacustrine origin. Fragments of wood occurred in it, 

 stained blue by phosphate of iron. It appeared probable from the depth 

 at which the clay was buried beneath locally derived material, upon a com- 

 paratively level surface, that it was of great antiquity, though possibly 

 younger than the glacial epoch. 



May 7 til, 1862, — ^The following communications were read : — 



1. " Note respecting the Discovery of a new and large Labyrinthodont 

 {Loxomma Allmani, Huxley) in the Gilmerton Iron -stone of the Edin- 

 burgh Coal-field," By Professor T, H, Huxley, F,H.S., Sec. G.S. 



Looking over the vertebrate fossils from Burdie House and Gilmerton 

 in the University Museum, Edinburgh, Professor Huxley came upon 

 some reptilian specimens — a fragment of the hinder part of the upper 

 wall of a cranium and some sternal plates of a Labyrinthodont, which, 

 from the obliquity of its orbits, he names Loxomma. The skull would be 

 about 14 inches long if perfect ; and the animal about 6 or 7 feet. 



2. " Note on a new Labyrinthodont {Pholidoc/aster 2>iscifortnis, Huxley) 

 from the Edinburgh Coal-field." By Professor T, H. Huxley, F.H.'S. 



The specimen on which this new form has been determined was placed 

 in the British Museum by Sir P. Egerton and Lord Enniskillen, who 



