Vol. 58.] GAPS IN THE LAs. 275 
Westerly vales draining into the Stour from the western escarp- 
ments and with a westerly fall show similar results in that area. 
The fall is also short. The Middle Liassic calcareous (ironstone) 
beds thin down to 4 or 5 feet.’ At the hill dipping into Brailes the 
thickness is greater. I have spoken before of a remnant of the 
Transition-Bed, and of the fish-bearing limestones and paper-shales 
of the Ammonites-serpentinus zone in that part of the Stour Vale, 
preserved in like manner to similar beds in the Cherwell area 
draining westward. 
There is no reason to doubt that the calcareous (ironstone) beds 
of the zone of Ammonites spinatus were formerly as thick on the 
eastern side of the Cherwell Vale as on its western side. We must 
not overlook the fact that there was some difference in the 
organisms and growth of the Ferrocrinoid-bank of the east. Why 
should not the waste be the same, with the overlying clays and 
limestones of the east side of the Vale, with the shorter fall? Vales 
of shorter drainage, whether on the scarp-edge to the west, or on 
the east side of the Cherwell, show preservation of minor zones of 
the Upper Lias constituting elsewhere gaps 1, 2, and 3. On the 
west side of a divide, with a fall opposite to the common 
dip of the country, massive calcareous beds dwindle in thickness, 
while overlying thin strata of limestone and clay, as well as the 
greater capping of tenacious clays, are better preserved than on 
the long fall with the common dip. 
I find the same preservation of minor zones of the Inferior and 
Great Oolite systems on the short flanks of a divide. Thus, in the 
long ridge of the boundary-lines of North-western Oxfordshire and 
South-eastern Warwickshire, remains of several of the lower 
divisions of the Great Oolite are found in faulted troughs on the 
side away from the prevailing easterly dip. In 1883,’ I pointed 
out the existence of these remnants and the great interest of their 
fauna. The lesser volume of drainage of the short slope made less 
waste of strata. ‘The faulted areas on the short slope appear also 
to have been of a more recent date of displacement than the longer 
underdrained slopes of the Cherwell Vale. When I am able to take 
up the description of the Great Ooijite remanié deposits that I 
have discovered, I shall hope to enter more fully into the question 
of their time and conditions of displacement. 
On p. 274 I have given a stratigraphical Table illustrating 
the gaps in the Upper and Middle Lias of England; and on 
pp- 276-77 Lists of the (more important) Fossils of the Upper and 
Middle Lias. 
* Later search has proved 13 feet at the head of the vale draining into 
Tysoe. 
2 * On the Relation of the so-called Northampton Sand of North Oxon to the 
Clypeus-Grit’ Quart. Journ. Geol. Soc. vol. xxxix (1883) p. 233. 
Q. J. G. $..No, 230. : 
