336 MR. F. W. HAEMEE OJS" THE LEN^HAM BEDS [Aug. 1 898, 



the water-level, of the unaltered type, but there is a roadside section 

 (No. 3 in fig. 4), near Butley Ferry, in the immediate neighbourhood, 

 where ferruginous Crag, made up of comminuted material without 

 fossils, comes down almost to the level of the marsh (see fig. 5, 

 p. 328). This belongs to zone G, the upper part of the formation, 

 according to Prestwich, but as such it seems there out of place, 

 being probably within 10 feet of the London Clay. The difficulty 

 disappears if we regard it as merely the altered form of the shelly 

 Crag present in the adjoining field. 



At Gedgrave Hall there is a large pit (No. 6) showing about 20 

 feet of indurated Crag, but immediately below it towards the marsh 

 is another (No. 7) composed of whitish shelly sand, the upper part 

 irregularly coloured by recent infiltration, in which few but the 

 smallest species of mollusca are present, Nucula nucleus and Donaoc 

 politus being specially abundant.^ A boring at this spot was 

 interrupted by tabular layers of limestone, very hard, and difficult 

 to penetrate. These were considered by Prestwich to be distinctive 

 of his zone D. We met with them, however, in no other boring, 

 though they may be occasionally observed elsewhere above the 

 water-line. I look on these bands as purely local, due to infil- 

 tration and redeposition of the calcareous matter, and as of no 

 stratigraphical significance. 



At the Broom Hill pit (No. 11), near the Keeper's Lodge, so much 

 resorted to by collectors, at which few specimens of gasteropoda are 

 found, the junction of the Crag with the London Clay was only 

 reached at a depth of 22 feet (probably 19 or 20 feet below the 

 marsh), Fragments of large lamellibranchs, and small shells, 

 perfect, were brought up constantly by the borer. Layers of 

 the former seemed to occur at 5 feet, 9 feet, and at the base of the 

 Crag. The upper part of the section exposed at this place has been 

 more or less affected by infiltration. The lowest beds are of a whitish 

 colour, but they gradually become more ferruginous upwards; in 

 places they seem to shade off into each other, so that it is difficult to 

 draw the line between them. Prestwich called the beds at Broom 

 Hill D & E, but if colour be a test, some of them should rather have 

 been placed in his zone G. The section is, however, instructive, 

 showing the process by which the upper part of the Coralline Crag 

 has been transformed.^ 



^ This is the bed regarded by Mr. Burrows as belonging to zone F ; see p. 325. 

 ' Among the material brought up by the borer at the Broom Hill pit I 

 noticed the following species : — 



Anomia striata. 

 Ostrea ungulata. 

 Pecten Gerardii. 



„ tigrinus. 

 Vectuncidus glycimeris. 

 Lucina horealis. 

 Cardita corbis. 



,, scalaris. 



,, senilis. 

 Astarte Basterotii. 



„ Burtinii. 



„ „ YSir.pisiformis. 



„ Galeottii. 



Astarte parvula. 

 Venus ovata. 



„ casina. 

 Cyprina islandica. 

 Tellina donacina. 

 Mactra triangula. 

 Corhula nucleiis. 



Turritella incrassata. 

 „ acutangula. 

 Bingicula buccinea. 

 Adeorbis. 



