278 Reports and Proceedings — Geological Society of London. 



REPORTS -A-HSTHD PROCBEDI1TGS. 



Geological Society of London. 



I. March 22, 1911.— Professor W. W. Watts, Sc.D., M.Sc, F.K.S., 



President, in the Chair. 

 The following communications were read : — 



1. "On some Mammalian Teeth from the Wealden of Hastings." 

 By Arthur Smith Woodward, LL.D., F.B.S., F.L.S., Sec.G.S. 



Mr. Charles Dawson, F.S.A., F.G.S., has ohtained two imperfect 

 molars, apparently of Plagiaidax, from beds of grit in the Wealden 

 near Hastings; and his associates in the work of exploration, 

 Messrs. P. Teilhard de Chardin and Felix Pelletier, have found 

 a well-preserved nrultituberculate molar of the form named Dipriodon 

 by Marsh. These specimens are described. 



Mr. Dawson said there Avere three horizons where bone-beds 

 constantly occur: (1) in the Upper Tunbridge Wells Sands just below 

 the Weald Clay (being the true ' Tilgate Grit ' of Mantell) ; (2) at 

 a great depth below the former, at the base of the Wadhurst Clay, in 

 the blue clay above, and sometimes associated with, the thick bed of 

 calcareous sandstone ('Blue Stone'); and (3) about 26 feet below 

 ISTo. 2 (at Hastings), at the top of the Ashdown Sand ; it is less 

 fossiliferous than either of the former, and is usually associated with 

 bands of calcareous sandstone. So far, mammalian remains had not 

 been discovered in No. 1 ; Nos. 2 and 3 had yielded the teeth ascribed 

 to Plagiaidax, and now jSTo. 3 had also furnished Dipriodon. 



2. " Some Observations on the Eastern Desert of Egypt, with 

 Considerations bearing upon the Origin of the British Trias." By 

 Arthur Wade, B.Sc, F.G.S. 



This paper deals chiefly with phenomena observed in the Eastern 

 Desert of Egypt, bordering the Gulf of Suez and that part of the lied 

 Sea which is adjacent to its junction with the Gulf. The mounds of 

 igneous debris which flank the coastal hill-ranges are described, and 

 their origin is discussed and connected with the raised-beach phenomena 

 present in the area. The distances to which fragments of igneous 

 rock derived from these hills have travelled in Egypt are shown. 



The shore-sands are next dealt with, and their origin ascribed 

 mainly to the breaking down of local rocks, and not necessarily to 

 the denudation of Nubian Sandstone areas as has been supposed. 

 In the marly beds connected with the recent shore-deposits, tiny 

 dolomite-rhombs, similar to those found by Dr. Cullis in the Keuper 

 Marls, are present. Some effects of wind-blown sand are described, 

 especially the wedging of the sand-grains into cracks produced by 

 other forces of disintegration. 



Deposits of rock-salt and gypsum are being laid down at present in 

 the area. The alteration of the calcium carbonate in recent shell-beds 

 to gypsum, with the accompanying destruction of organic remains, is 

 noted ; and its significance with regard to the origin of gypsum-beds 

 and the concurrent absence of fossils in some of the older series of 

 strata is pointed out. Analyses of different deposits are given, and 

 the presence of sodium carbonate and epsomite crystals is proved in 



