William Hill — The Upper Chalk of Lincolnshire. 405 



notewortliy, as it is not uncommon in the zone of Holaster planus, 

 but it is curious that Echinoderms should be so rare in this set of beds. 



There is no appreciable dip in either of the above-mentioned 

 quarries, and it is therefore impossible to say for certain whether 

 the chalk near Fotherby is stratigraphically higher or lower than 

 that at Boswell, but the balance of available evidence is in favouf 

 of their being a little lower, for the Fotherby quarry is at a rather 

 lower level than the other, and the absence of Uchinocorys suggests 

 a lower horizon. 



Similar chalk with intercalated layers of flint extends northwards 

 along the eastern border of the Chalk Wolds, and exposures of them 

 are mentioned in the Survey memoirs on the geology of Sheets 

 83 and 86, but no fossils indicative of Upper Chalk were obtained 

 from any of them. In 1899, however, I found Chalk with Holaster 

 planus in a quarry half a mile south-east of Kermington, near 

 Brocklesby, where the following succession was visible : — 



ft. in. 



Soil and rubble 4 



Hard wlxLte clialk, weathering into thin irregular platy pieces ... 19 



Continuous layer of solid grey flint 5 



Hard white chalk as above, with layer of flat lenticular flints ... 3 6 



Continuous layer of solid grey flint 6 



White chalk, rather soft and shaly, at the top Bolaster planus ... 10 



Hard white chalk, breaking into thin flatfish pieces 3 6 



Grey flint, nearly continuous, but separated in places into detached 



tabular flints 6 



Hard white chalk with only a few scattered nodular flints ... 9 



From the lithological characters seen here I believe this quarry 

 is just in or just below the zone oi Holaster planus. In the large 

 Chalk quarries at Barrow I found a good specimen of Echinocorys 

 scntatus, besides fragments which I should refer to this species. The 

 lithological features of the Chalk at this horizon are well marked ; 

 the Chalk itself is firm, almost hard, and weathers into thin platy 

 pieces, becoming softer at the higher horizons. The flint, besides 

 occurring in the ordinary nodular form, occurs also in lenticular 

 masses five or six inches thick, which can only be described as 

 ' tabular,' though they do not form the even continuous floor seen 

 in the tabular flint of the South Coast cliffs. They present rather the 

 appearance of a series of large mammillated flints all on the same 

 plane, merging in places to one unbroken layer of considerable extent. 



From the foregoing evidence the fact that Upper Chalk occurs 

 in Lincolnshire seems well established. I could find, however, 

 no evidence to indicate an exact horizon which could be taken for 

 its base, nor could I find a quarry or series of quarries to give me 

 the passage of Chalk with flint nodules in the zone of Terehratulina 

 to that of Chalk with the tabular flint layers. 



The lithological features which are associated with M. Leslzei, 

 H. planus, and Echinocorys scutatus, viz., firm chalk with layers of 

 massive tabular flint, passing upward to softer chalk with nodular 

 flint, continues through Yorkshire. For instance, H.planus associated 

 with Echinocorys scutatus occurred in chalk with massive tabular flint 



