290 :\IR. T. 0. BOSWORTH ON THE [JllUe I912, 



On account of cleavage, the grains seem hardly able to resist 

 fraying. Even spherical grains bristle with small sharp pro- 

 tuberances. In some sands, hovrever, the rounding is so intense 

 that the grains are almost spherical, with minute pits like those 

 described on the garnets. 



llutile occurs chiefly as smooth round grains or as worn prisms ; 

 but some angular fragments are derived from local rocks, as, for 

 example, from the South Leicestershire syenites. The colour varies 

 from deej) to pale amber. 



Geniculate twins are not uncommon. Occasionally in the marls 

 occur slender golden-yellow crystals of almost perfect form. 



Tourmaline occurs abundantly as rounded grains and worn 

 prisms. Green, blue, and mauve grains are fairly plentiful. 



]^Iagnetite is abundant, both as rounded grains and as angular 

 fragments locally derived. 



Anatase is present in a few cases, notably close to the igneous 

 inlier of Sapcote and Stoney Stanton. 



Tt occurs in well-formed plates parallel to (001), bounded by 

 narrow (100) and (001) faces M'ith bevelled edges. Tlie largest 

 plate measured -08 mm. The colour is pale straw-brown. 



Barytes is fairly common in the seams of quartzose dolomite, 

 probably as a crystalline precipitated cement. 



[lu the complete paper a table is given, sboTving the relative distribution of 

 the minerals.] 



The Ripple-Marks and Salt-Psendomorphs. 



These were found on almost every grey bed, when suitably 

 weathered. The quartzose-dolomite seams are almost invariably 

 rippled, and bear salt-pseudomorphs in swarms upon the crests. 

 Probably the ripples were formed in shallow desiccating pools, and 

 were controlled by wind. 



Data as to the trend of the ripples are tabulated, and it appears 

 that, although there are ripples trending in almost every direction, 

 the majority trend north-westwards, and are steepest on the north- 

 east side, indicating a prevalent south-westerly wind. 



Summary of Facts established. 



(1) The Charnian Hills were covered up under conditions which 

 precluded rock-decay. 



(2) The rock-surface was affected by wind-erosion. 



(3) Screes, breccias, stones, and grit were derived only from 

 the rock immediately at hand. 



(4) The stones may be angular or fretted, but they never resemble 

 beach or river-pebbles. (jS"either is there any evidence of littoral 

 drift.) 



(5) Around each buried hill the beds dip radially away, and they 

 lie in catenary fashion across the valleys. 



