TRANSACTIONS OF SECTION OC. 483 
The Geological Survey found its stratum to be a convenient line of demarca- 
tion, as it rested upon a base of limestone graduating into the Stonesfield series. 
The discovery of other strata on the borders of Hast Oxfordshire and West 
Oxfordshire necessitates the division of the Great Oolite and the separation of 
the new beds proposed to be classed as Sub-Bathonian. The old survey lines are 
thus sustained. The sequence suggested is as follows :— 
Urrrr Great Ooxire.—l. Terebratula mazillata beds. 2. Calcaire a 
Echinodermes. ‘ 
Lower Great Oouire.—l. Striped Limestones. 2. Rhynchonella concinna 
beds. 3. Stonesfield Slate. 
Sus-Barnontan.—l. Striped Limestone and Crinoid beds. 2. Nezran series. 
3. Striped Crinoid Marls. 4. Chipping Norton Limestones. 
The new railway (Aynhoe and Ashendon) is cut along the divide between the 
Cherwell and Ouse rivers. The missing Sub-Bathonian series of the West lands 
were brought to view. Prominent there were White Calciferous Limestones and 
Striped Marls and Limestones. The author found the chalk-like limestone to be 
crowded with the decayed heads of large crinoids of which it was made. Above 
it passed into a blue crystalline limestone, here and there; a packed mass of 
the brachial joints of the crinoids. At the base of all was the stratum of black 
vertical stripes (the striped beds), the place of crinoid column and rootlets filled 
with carbonaceous granules from dark beds above. The beds are now known 
to be marine, not estuarine, as previously described. Sections of the chalk-like 
limestone showed a pavement of discs of the crinoid (Apiocrinus) calyx. 
9. The Value of a Knowledge of the Rock Soil Distribution of Plants in 
Tracing Geological Boundaries. By A. R. Horwoop. 
During the last ten years the new science, Ecology, has made great strides, 
and one branch of it—that which deals with the distribution of plants upon 
different soils—has become recognised as a sure means of determining the type 
of vegetation which characterises each soil. Conversely, the type of vegetation is 
an indication of the soil. 
Whilst the geological formations, with the sub-divisions, are numerous, the 
soils may be roughly divided into six classes, and the influence of lime in the 
soil upon plant distribution is especially marked. 
These facts now systematically studied have an important bearing upon 
geology, more especially in the delineation of zones and sub-zones. 
It is well known that certain formations, such as the coal measures, Keuper, 
Rheetics, Lias, &c., have intermittent thin bands of limestone, &c., which are 
not always to be seen in the field, in section or otherwise, and difficulty arises 
in tracing them across country for this reason. 
In a similar way the existence of irregular beds of sand in glacial deposits 
is often obscured by vegetation or other causes, and their existence is frequently 
a matter of conjecture. As these details of mapping are of importance, especially 
to the builder, agriculturist, and horticulturist, and economic geology is to-day 
a great factor in survey work, any accessory aids that can be rendered by the 
ecologist are worthy of the consideration of geologists. 
Moreover, ecology has advanced so far already that surveys of several 
regions have been made and exact vegetation maps published, so that it is 
expected that this science, which is of such importance from the economic, as 
well as the stratigraphic, standpoint, will have shortly to be established upon 
a national basis, and ecological surveys carried out by the State. This neces- 
sity arises primarily from the purely ecological value of the work, and since 
ecology and geology are interdependent, there is additional reason for urging 
that the former be recognised as fully as the latter as of national importance. 
It is therefore suggested that till this is accomplished geological survey work 
should be carried out in conjunction with ecological surveys, or, at any rate, that 
those at work in each district upon ecological surveys be asked to co-operate, 
where required, with geological surveyors, especially in those areas where this 
co-operation would be of great assistance in tracing boundaries of local beds. 
Further, it is suggested that a definite effort should be made to accomplish 
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