Vol. 50.] BOEINGS AT CULFOED, WINKEIELD, WAEE, AND CHESHUNT. 491 



Description of Samples. 



1 . Esther hard, yellowish, marly chalk, very like the material 

 which occurs in the marl below the Melbourn Rock at Whittington, 

 near Stoke Ferry in Norfolk. 



2. Compact and rather hard, homogeneous, white chalk. Under 

 the microscope it shows a fine amorphous matrix in which are 

 numerous single calcareous cells, many of which are empty. It 

 most resembles slides of Upper Chalk. 



3. A flint, black throughout, without any white rind or envelope. 



4. Very soft, pulverulent chalk, and in its dry state almost pure 

 white. It is either one of the softest beds of the Chalk Marl, or 

 part of a mashed-up core, probably the latter. 



5. Light grey marl : effervesces freely, but is nevertheless decidedly 

 argillaceous. Mr. W. Hill cut a piece of this and reports that its 

 structure closely resembles the marly Upper Gault of Norfolk ; in 

 his opinion it is Gault. There was no note of the exact depth from 

 which the sample was taken. 



6. Dark grey marl, evidently a Gault marl, but it effervesces freely 

 with hydrochloric acid. 



7. Phosphatic nodules and fossils, including Belemnites attenuatus, 

 Nucula pectinata, fish-vertebrae, and part of a gasteropod. 



8. Dark grey clay, effervesces slightly. 



9. Dark-grey, sandy clay. An extra sample from 600 feet is a 

 dark clay, with larger grains of sand. 



10. Very soft, wet, sandy clay ; when washed this is found to 

 consist of very fine mud enclosing a quantity of sand, the grains of 

 which vary much in size ; the greater part — perhaps two thirds — of 

 the sandy material is clear white quartz, partly in rounded partly 

 in angular grains. The residue consists chiefly of small water- 

 worn fragments of grey slate or argil lite, closely resembling material 

 occurring in the Palaeozoic rocks below. There are also a few 

 grains that seem to be glauconite. Probably the bed from which 

 this sample was obtained is really a somewhat dirty or silty sand, 

 the fine mud which now binds it into a sandy clay having been 

 derived from the Gault above and mixed with it in the process of 

 boring. 



11. Several samples. A greyish-brown stone, from 632 feet, 

 containing many small brown bodies looking like decomposed oolitic 

 grains of iron ; a grey gritty-feeling stone ; a piece of lignite, 

 embedded in brown ferruginous sandstone containing large grains 

 of yellow and brown quartz; lastly a fragment of an ammonite. 



Both these grey stones are calcareous, and when sliced and 

 examined under the microscope are seen to be limestones of a very 

 peculiar type. They consist mainly of shell-fragments set in a 

 matrix of shell-dust, cemented by calcite ; a few grains of quartz 

 are seen, but the grittiness of the rock is evidently due to the 

 shell-fragmeuts, as in the case of the Totternhoe Stone. Most of 

 these fragments are pieces of echinoderm-shell, some are molluscan, 

 and there are a few foraminifera (chiefly Textularia). The brown 



