Vol. 50.] MR. E. CHAPMAN ON THE BARGATE BEDS OF STTRREY. 67& 



Commencing above the ash-coloured sand (evidently of Hythe age, 

 which therefore does not here concern us), 12 feet of which is seen, 

 there is a bed of greenish sand, about 3 feet thick. In its lower 

 half this bed is coarsely current-bedded, and the lamination strongly 

 marked by carbonaceous bands, with argillaceous material, which 

 increases nearer the top. It contains many remanir fossils and a 

 considerable proportion of oolitic ironstone-grains resembling those 

 of the iron-shot sand of Lincolnshire, with the difference, however, 

 that these Bargate grains appear somewhat flattene'3.. There are 

 also occasional doubly-terminated crystals of quartz. Foraminifera 

 occur, but rarely, in the more argillaceous portions, amongst others 

 Textularia prcelonga, Reuss. 



Next above is a band of variable thickness, usually about 3 inches, 

 of large and small subangular pebbles in clay, including clay -iron- 

 stone concretions, pieces of oolitic ironstone, fragments of lydite, 

 and'waterworn pieces of ammonites and other fossils. From the 

 pale ochreous clay of this band a rich assemblage of mostly minute 

 foraminifera, ostracoda, and sponge-spicules was obtained. These 

 are not abundant, and are only found after careful search. For 

 the list of these and descriptions of new species, see p. 688. 



Various minerals were obtained from the sand associated with this 

 clay ; and I am greatly indebted to Dr. W. Fraser Hume, F.G.S., 

 for kindly supplying the following notes upon them : — 



" The most numerous of the heavy minerals are undoubtedly the 

 zircons. These occur in two forms : (a) as crystals, (b) as rounded 

 grains. The largest crystal has a length of *178 mm. and a breadth 

 of -04:4 mm. The mineral possesses all the usual characters. The 

 rounded grains are far more numerous than the crystals above 

 mentioned. These latter must have undergone considerable friction, 

 for, not only have perfect pebbles of zircon been formed, but these 

 have also been often fractured and sometimes apparently broken 

 completely across. 



" Rutile. These are not so numerous as the zircons. Two different 

 kinds are observable. (1). Forms which at times show traces of a 

 prismatic habit, but are generally in a more or less rounded con- 

 dition. Atypical specimen had a length of *165 mm. and a breadth 

 of *075 mm. (2). The second variety occurs in grains, of a clear 

 golden-yellow colour, and these are especially prominent owing to 

 their high refractive index and strongly adamantine lustre 



" Tourmaline. A few specimens of this mineral are present. They 

 are of distinct prismatic habit, bounded by rhombohedral faces, 

 these latter being generally only visible on one side. 



" Kyanite. Cleavage-flakes of this mineral are by no means un- 

 common. These flakes are generally rectangular in shape, and 

 •with an average length of "131 mm., the cleavage being well-marked 

 parallel to the short axis. This mineral agrees with the kyanite 

 figured from the Bagshot Sands of Hampstead Heath (Teall's 

 ' British Petrography,' pi. xliv. fig. 2). 



" Quartz. Occurs in well-rounded grains, which are limpid, or at 

 most show minute lines due to the presence of gas-cavities. 



