456 EH. Neaverson—Foraminifera of the Hartwell Clay. 
which seem to be the typical Hartwell forms. The deposit at 
Long Crendon, near Thame, represents a lower horizon than that 
usually worked at Hartwell. It contains some of the characteristic 
Hartwell Clay fossils, but the ammonites present different characters, 
being large inflated Perisphinctids with fairly coarse ribs. Similar 
ammonites were found at Hartwell years ago when the workings 
were deeper. At Wheatley and Shotover Hill the clays contain 
nodules enclosing ammonites of a still different type—fine-ribbed 
Perisphinctids involute in youth becoming evolute later; coarse- 
ribbed species, however, occur at both localities. These clays have 
until recently been referred to the Kimmeridge Clay, but an 
_examination of the residues has disclosed the presence of glauconite, 
a mineral which appears to be absent from the typical Kimmeridge 
Clay of the district.1_ This, and the occurrence of typical Hartwell 
Clay belemnites in the clay at Wheatley appear to indicate that 
these beds should be classified with the Hartwell Clay as Bononian.? 
The following is a summary of the beds under discussion :— 
4. Typical Hartwell Clay of Hartwell, Aylesbury, Bierton, and 
Whitchurch. 
3. Hartwell Clay of Long Crendon—a lower horizon than that 
usually worked at Hartwell. . 
2. Highest ‘“‘ Kimmeridge Clay”? of Wheatley and Shotover 
Hill—a sandy clay. 
1. Blue Clay of Wheatley and Shotover Hill with nodule band 
as basement bed. 
GENERAL CHARACTERS OF THE CLAYS AND OF THE MICROZOA. 
The following notes give the general characters of the microzoa ; 
and also of the sediments from the various localities, pending a 
complete petrographical description. 
Hartwell.—Abundant quartz and glauconite grains occur, many of 
the latter being casts of Foraminifera; marcasite is common, 
sometimes filling tests of Foraminifera, more often as spherical 
concretions. Ostracods * are common, and Foraminifera abundant ; 
hooklets from the tentacles of a belemnoid, remains of echinoderms, * 
fish-teeth, otoliths, and scales are also found. 
Aylesbury and Bierton. — Quartz and glauconite grains are 
abundant as at Hartwell; spherical concretions of marcasite also 
are common. Foraminifera and ostracods are common, but the 
number of species is relatively small. 
Whitchwrch._—Selenite is the commonest mineral in the residues, 
occurring often in well-formed crystals. Quartz and glauconite 
are common, whilst marcasite frequently occurs. Foraminifera 
1 See also A. M. Davies, Q.J.G.S., vol. Ixviii, 1997, p. 36. 
2 See A. M. Davies, Introd. to Paleontology, 1920, p. 385. 
3 Chapman, Proc. Geol. Assoc., vol. xv, 1897, p. 97 (list of species). 
« Bather, Grou. Mac., 1916, p. 302. 
