England and the " Red Chalk " of the Eastern Counties. 165 



above its basement-bed we found Inoceramus anglicus Woods. 

 Mr. S. S. Buckman has submitted to us a well-preserved fragment of 

 Schloenbachia varicosa from the clay in an adjacent plot of ground. 

 At a locality to the east of Thame station a well-sinking has recently 

 shown us that there, too, the Gault rests on a Parbeck limestone. 

 The overlap is also well seen in the neighbourhood of Aylesbury. 



Just south of Leighton Buzzard the true Lower Gault crops out, 

 the interruptus-G\a,y here resting conformably, as usual, upon the 

 mammillatus-hed, as first reported by Mr. G. W. Lamplugh. We 

 have shown elsewhere that a special interest attaches to the series 

 as here displayed. Owing to favourable conditions of preservation, 

 the fauna of the tardefurcala-zone, situated immediately below the 

 mammillatus-hed. and characterized by species of Leymeriella,^ 

 is well represented within the 4 feet of sandy clay immediately 

 underlying the interruptus-Gau.]t and resting directly on the 

 Lower Greensand. We have described in the paper just cited how, 

 in the neighbourhood of Shenley Hill and Heath, north of Leighton 

 Buzzard, the Upper Gault overlaps on to the Lower Greensand. ^ 

 Since that description was published we have made further visits 

 to those sections, as well as to others in the vicinity, and have fully 

 confirmed our previous observations as to thp inverted order of 

 zones in the transported masses of Cenomanian limestone and Upper 

 Gault clay at Shenley HilJ. As regards the overlapping Upper Gault, 

 further information has been obtained in two exposures near Heath 

 and in a small opening south-east of Shenley House. The basement- 

 bed of ochreous sandy clay, with grit grains, pebbles, and fragments 

 of ironstone, is here succeeded, as before described, by sparsely 

 fossiliferous, poorly bedded clay-breccia composed of small 

 fragments and pellets of clay of varying colour and texture. This 

 passes upwards into more evenly bedded and slightly silty clay 

 containing Terehratulce, Inoceramus concentricus Park., and fish- 

 scales, overlain in turn by paler Gault with Inoceratniis sulcatus 

 (common) and ammonites of the rostratus-ieMna., chiefly in a 

 phosphatic bed. 



At Clophill, near Ampthill, the i)iterruptiit-Gau\t is again seen at 

 the outcrop, with +he mammillatuf^-zone below it. At Biggleswade 

 the same beds were found in a well-sinking below Boulder Clay, on 

 which rests the remarkable transported mass of Ampthill Clay 

 described in 1903 by Mr. H. Home.^ 



Norfolk. — North-east of Cambridge the Gault, which is poorly 

 exposed, disappears beneath the alluvium of the Fenland east of 

 Ely and does not reappear until the neighbourhood of West Dereham 

 is reached. Nothing was known of the characters of the formation 

 where it is concealed beneath the Fens until lecently, when several 



1 F. L. Kitchin & J. Pringle, Geol. Mag., Vol. LVII, 1920, pp. 52,53. 

 ^ See also F. L. Kitchin & J. Pringle, " Excursion to Leighton Buzzard " : 

 Pt-oc. Geol. Assoc, vol. xxxii, 1921, p. 173. 

 * Quart. Journ. Geol. Soc, vol. lix, p. 375. 



