58 D. G. Lillie—Fossil Flora, Bristol Coal-field. 
EXPLANATION OF PLATE VI. 
Fie. 1. This photograph of the northern escarpment of the South Downs near 
Ditchling Beacon affords an admirable illustration of the simple steep - 
coombes to which reference is made in the paper. Ditchling Beacon is 
shown on the high point about the middle of the view. At the foot of 
the steep escarpment is shown the ancient hedge which separates the 
down land trom the arable land of the Weald. The latter in prehistoric 
and early historic times was largely forest land. 
., 2. The Seven Sisters, a series of alternate valleys and lofty cliffs, owe their 
shapes to a former system of branching dry valleys, much of which has 
been destroyed, probably by marine erosion. 
IJ.—Nores on rue Fosstr Frora oF tur Brisrot CoaL-FIEerD. 
By D. G. Lrizin, B.A., St. John’s College, Cambridge. 
(Rl ACRE AVele) 
ORE than twenty-three years have now passed since Dr. Kidston 
published his memoir on the fossil flora of the Somerset and 
Bristol Coal-field, and in the meanwhile no further additions .to our 
knowledge have been made. Kaidston’s paper was chiefly concerned 
with the plant-remains of the southern or Radstock portion of the 
basin. ‘lhose from the northern or Bristol area have only been studied 
incidentally. This would seem quite natural on account of the greater 
size and industrial importance of the Radstock Coal Series, and from 
the fact that this locality has been long known to yield the finest and 
best preserved impressions of fossil plants to be found in any coal-field 
in the British Isles. The collieries in the Bristol district are com- 
paratively few and smaller, fossil plants being much scarcer and less 
well preserved. 
In view of the fact that the Bristol area is becoming less extensively 
worked every year, it has seemed to me worth while to collect as 
many plants as possible from this district, in the hope of adding to 
those already recorded. It also has been desired to obtain a flora 
sufficiently characteristic to mmdicate the paleobotanical horizon as 
compared with those of the Radstock district and other coal-fields. At 
present the evidence rests entirely on stratigraphical data. With this 
end in view, I spent some weeks, during the last two summers, in 
collecting fossil plants from the waste-heaps of the seven collieries 
which alone appeared to be still working in the Bristol district. 
In recent times several collieries have been completely abandoned, 
including all those on the Nailsea basin, and the possibility of obtaining 
plant-remains from this coal-field is becoming less every year. The 
spoil-heaps of four of the collieries now working proved to be almost 
completely barren on both occasions when [ visited them, the shale 
being much slickensided and all organic remains obliterated. Thus 
there remained only three collieries from which plants can be collected, 
und one of these is exceedingly small. A week’s work was con- 
sequently sufficient each year to practically exhaust the spoil-heaps. 
The physical features and stratigraphy of the Bristol district 
have been described by several writers! in tke past. In more recent 
1 See Kidston, Trans. Roy. Soc. Edinb., vol. xxxiii, pt. ii, p. 338 note. 
