244 PROCEEDINGS OP THE GEOLOGICAL SOCIETY. [Feb. 5, 



conversion into slates ; and that as a result many pits for the pre- 

 sent had been thrown out of work. 



The superincumbent beds at Collyweston and Easton have an 

 aggregate thickness varying according to situation from 15 to 25 

 feet, and present lithological and sectional peculiarities not to be 

 found in any sections in the Lincolnshire Limestone which I have 

 elsewhere had the opportunity of examining ; but which (as Mr. 

 Judd informs me) are not very unlike those which characterize some 

 sections in Lincolnshire. 



From the number and great extent of the slate quarries, it would 

 be expected that some variations in the sections would be exhibited. 

 This, to a certain extent, is the case — as will be found upon a com- 

 parison, one with another, of a section taken by Prof. Morris prior 

 to 1847, and published in his " Notice " in the ' Transactions of the 

 British Association ' for that year, one noted by me several years 

 ago, and others taken by me during the recent autumn. Beds pre- 

 sent in some sections are wanting or have changed their character 

 in others ; and beds traceable through several sections are thicker 

 or thinner according to locality. 



Section taken at Collyweston by Professor Morris prior to 1S47- 



ft. in. 



1. Compact oolite in shivers 7 



2. Oolitic freestone 2 6 



3. Marly oolite 2 G 



" Cream-coloured marly limestone, containing zones of 

 shells of which the Ncrincea cingenda and other species, 

 Lucina, Pholadomya, Modiola plicata, are abundant ; 

 with patches of fragments of ferns (Pecopteris poly- 

 podioides) and other plants (Zamites), not occurring 

 in regular layers." 



4. Concretionary sand bed ("beds of sand and sand-rock") ... 1 6 



5. Compact crystalline ragstone ("with Nerincea and Ferns")... 1 6 



6. Brown rubbly incoherent sand, with concretions 2 



" A concretionary bed of sand, with irregular cylindrical 

 ramose bodies of sandstone, resembling fucoid stems." 



7. Slate beds — " Calcareo-siliceous beds, grey and brown." 



Former Section taken by S. S. 



ft, in. ft. in. 



1. Flaggy limestone, slightly ferruginous, and more 



arenaceous and siliceous than the ordinary Lin- 

 colnshire Limestone of the district. [This bed 

 represents bed 3 of Professor Morris's section.]... 3 to 4 



2. Sand bed — somewhat ferruginous, and containing 



fantastic concretionary masses. [4 of Morris.]... 3 to 4 



3. Flaggy limestone — sometimes blue-hearted. [5 of 



Morris.] 3 to 4 



4. Peculiar laminated bed, made up of alternate layers 



of sand and calcareous sandstone, each about half 

 an inch in thickness ; these are from 40 to 50 in 

 number, and the edges of the sandstone layers 

 stand out in relief upon the surface of the bed. 

 In one section this bed presents the most re- 

 markable wavy distortion. [6 of Morris?] 2 to 2 G 



b. Hard compact blue-hearted limestone in courses ... 3 to 5 



