222 /. W. Judd — On the use of the term Neocomian. 



immediately below the Chalk simply Sand, but in the table 

 accompanying the first part of his map in 1812, he emploj'^s the 

 term " Green Sand " for the same bed, and continues to use it in all 

 his later works. It would appear therefore that the use of this term 

 originated between 1799 and 1812. Smith's original observations 

 on the strata between the Chalk and the Oolites were made in 

 Wiltshire, a district where the beds between the Gault and the 

 Upper Oolite are almost entirely hidden by the overlap of the 

 Upper Cretaceous. In the study of this district he appears to have 

 been greatly assisted by his friend the Eev. Joseph Townsend, then 

 rector of Pewsey, who in his work " The character of Moses 

 established for veracity as a historian," speaks of the beds below the 

 Chalk as being successively "Green Sand," "Grey Sand," and "Eed 

 Sand." That Smith, whenever he used the term " Greensand," 

 restricted it to the sands immediately below the Chalk and ahove the 

 Gault, will be seen by a reference to his various extended Sections 

 and County Maps, pviblished between 1819 and 1824. When he 

 afterwards became acquainted with the Neocomian and Wealden 

 strata of the South-east of England, he not unnaturally referred 

 them to several members of the Upper Oolite, considering the 

 Kentish-rag as Portland-stone, part of the Shanklin Sands as 

 Portland Sand, and the Weald Clay as Kimmeridge or Oxford Clay. 

 The author who first fairly described the succession of the beds 

 between the Chalk and the Oolites was Thomas Webster, who, in 

 his Letters, written in 1811, and published in 1816, in Sir Henry 

 Englefield's " Isle of Wight," gives the following as the order of the 

 strata in that island : — 



1. Chalk. 



2. Greensand and Firestone. 



3. Blue Marl or Gault. 



4. Ferrnginous Sands. 



Unfortimately, Webster confounded, under the name Ferruginous 

 Sands, both the Shanklin Sand and the Hastings Sand, regarding 

 the Weald Cl;iy as only a subordinate stratum. It is evident, how- 

 ever, that bolh Smith and Webster, in spite of their misapprehensions 

 concerning the beds below, uniformly and consistently applied the 

 term Greeyisand to the sands immediately below the Chalk and above 

 the Gault. 



When, however, we turn to the works of the writers on these 

 beds, who immediately succeeded Smith and Webster, we find the 

 greatest confusion produced by the misapplication of the term 

 Greensand. Greenough, in his Geological Map of England and 

 Wales, published in 1816, calls all the beds between the Chalk and 

 the AVeald Clay " Blue Marl and Greensand." Dr. Buckland, in his 

 Sj'noptic Table, calls both the sands above and -those below the 

 Gault, '• GreeTisand ;" while Dr. Mantell, in his " Geology of 

 Sussex" (1822), names the former "Malm Eock " and the latter 

 " Greensand." Sedgwick, however, in his paper in the " Annals of 

 Philosophy" (1822), rightly follows Webster, calling the beds 

 between the Chalk and Gault " Greensand," and including all the 



