234 Reports, and Proceedings — Geological Society of London. 



The difference observable in the artificially worked stones from 

 defined areas on both sides of the Zambesi is shown by a comparison 

 of numerous specimens collected by the author. The very large 

 majority of flakes and flaked stones having no trace of design over 

 those that can be considered as implements, however rough, suggests 

 that the manufacture of stone tools on a large scale was here carried 

 on for use in the sand-covered country on both sides of the Zambesi, 

 where there is no stone ; and the difference in the proportion of 

 sharp unworn specimens to those apparently water-worn seems to 

 show that while many were made on the ground, the flakes and 

 refuse of the making of many more were brought down from the 

 tributary valley on the east. 



The author considers that there is no evidence as to the age of 

 the implements found near the Zambesi ; none have been discovered 

 in gravel that belongs to that river, and the presumption appears 

 strong that they were made from quartzite found on the surface 

 since the Eatoka Gorge was eroded. 



2, " A Contribution to the Petrography of the New Eed Sand- 

 stone in the West of England." By Herbert Henry Thomas, M.A., 

 B.Sc, P.G.S. 



The paper is supplementary to that which dealt with the 

 mineralogical composition of the Pebble-bed, and was published in 

 vol. Iviii of the Quarterly Journal (1902), p. 620. The results 

 obtained are based on the microscopic investigation of a large number 

 of samples taken from various New Red horizons and localities in 

 Devon and Somerset. 



The author gives a list of minerals identified, and tables showing 

 their distribution. In the description of certain mineral species, it 

 is suggested that anatase occurs both as detrital crystals and as 

 crystalline groups formed in the rocks since their deposition. The 

 foi'ms presented by grains of staurolite as well as certain crystals of 

 tourmaline with an unusual habit are described. 



It is recognized that the various divisions of the New Red Sand- 

 stone, namely, the Lower Breccias and Sandstones, the Lower Marls, 

 the Pebble-bed, and the Upper Marls and Sandstones, although 

 linked together by a general similarity of mineralogical composition, 

 present physical and mineralogical differences indicative of variations 

 in the source of supply and conditions of deposition. 



The rounding of the grains is most complete (millet-seed) in the 

 sandstones of the Lower Breccias and Sandstones, a feature continued, 

 but in a less striking manner, into the overlying division. 



With regard to the vertical and horizontal distribution of minerals, 

 it is found that staurolite is abundant in the Lower Breccias and 

 'Sandstones of the extreme south of Devon, but less plentiful north- 

 wards ; that garnet is present in all the New Red rocks of North 

 Devon and Somerset, but in South and Central Devon only occurs 

 in the Lower Marls and in the Upper Marls and Sandstones. 



