B. Thompson— Clay Beds by the Ouse. 25 
Stoke Goldington. The attack was a short one, and the victory 
complete for the Upper Lias theory. Below is the section then 
made :— 
Section at SroKE Gotprneron Brickyarp (August, 1906). 
ft. in. 
1. Som ... : or 2feetto 38 0 
2. River GRAVEL. Ae gray el almost exactly like that to be found at several 
other places between here and Olney, containing chalk, flint, Bunter 
pebbles, Great Oolite limestone, etc. ... 4 0 
In one part of the section only there is a kind of junction clay 
containing fragments of Ostrea, and therefore probably Oolitic in 
origin, though “not necessarily so. ‘Thickness not more than about 
6 inches. 
3. Upprr Lias Cray. Good typical material, not variegated, not bleached, 
not disturbed. Containing some iron pyrites in thin slabs, also larger 
pieces up to 2 or 3 lbs. in weight. The iron pyrites is not obtrusive 
in the clay, either as lumps or by discoloration ae 506 FUSE Os 
Fossils foun :— 
Ichthyosaurus (vertebra). 
Ammonites fibulatus (singly and in bunches). 
Ammonites of the subplanatus group? (fragments). 
Belemnites and phragmocones (fragmentary). 
Cerithium costellatum, Munst. (part only, but that good). 
The clay has been proved to be the same for a further depth of 
10 feet by means of a well (or sump), so that a uniform clay 
extends for a depth of at least 18 feet below the river gravel. The 
fossils recorded above came from below the 8 feet now exposed, say 
from a depth of 10 feet at least; and considered in conjunction with 
the rareness of all fossils, they indicate the upper part of the 
‘Unfossiliferous’ beds a little below the ‘ Cerithium’ beds or 
‘Lower Leda-ovum’ beds of Northamptonshire,’ Cerithium costellatum 
being one of the forms nearly always found associated with the 
abundant Cerithium armatum. Mr. Woodward’s record of ‘ Nail-head 
spar’ fits in admirably with the horizon suggested. 
In my own cabinets the fossils from the unfossiliferous beds (of 
Judd) are labelled ‘ Fibulatus” zone, not that Ammonites fibulatus 
is confined to the zone; indeed, the best specimens I have come from 
the Leda-ovum beds of the south-western parts of Northamptonshire,” 
but because for some 70 feet of Upper Lias, at least in Northampton- 
shire, it is the only ammonite that one is pretty certain to find traces. 
of, and if it is found where all other fossils are very rare the zone 
is identified, but near the bottom and near the top of the zone other 
fossils are not quite so rare. 
Some interesting problems are suggested by the occurrence of 
such comparatively low beds of the Upper Lias on the border of the 
Ouse Valley, such as—Are the upper beds of the Upper Lias missing ? 
Does the Great Oolite rest directly on the Upper Lias? Is the 
Northampton Sand entirely absent, and if absent, why? etc. We 
will consider the evidence available on these points. 
1 Beeby Thompson, ‘‘ The Upper Lias of Northamptonshire,’’ pt. vi: Journ. 
Northants Nat. Hist. Soc., vol. v (1888), p. 54. 
2 Ammonites fibulatus appears to continue into successively higher beds of the 
Upper Lias as we go in a south-westerly direction. 
