312 SECTIONAL TRANSACTIONS.—C. 
(c) An Hpidermis of fusiform cells. A thick cuticle is present. Stomata occur 
sparingly. 
The internal morphology of the rhizome and sporangium is also described. Other 
genera are represented, including types closely allied to Thursophyton and other 
types still under investigation. 
9. Mr. EH. Sr. Jonn Burton.—The Barton Beds of Barton Clef. 
The beds described belong to the upper division of the Eocene System, and they 
form the cliff section along the Hampshire coast at Christchurch Bay, beginning close 
to Cliff End near Mudeford, and ending at Long Mead End near Hordle, a distance of 
four miles. 
A remarkable sequence of Lower Tertiary strata is exhibited, containing a fine 
and varied assemblage of fossils which are principally of marine origin. The cliffs 
themselves attain a height of close on a hundred feet, though rather more than that 
at the highest point near Barton Court. They are made up of clays and sands, capped 
by plateau gravel which reaches a thickness of 25 feet. The clifis show, however, 
this important difference when compared with those at Bournemouth, that they 
possess far fewer and shorter chines. 
The succession may be briefly summarised :— 
90 Feet. 
1. White and yellowish sand with numerous fossils (Long Mead End Bed). 
H a Batillaria pleurotomoides in sand. 
Bie 42. Hard dark sand (Oliva branderi Zone), merging into grey and white sand 
Ps | generally unfossiliferous, 
3. Bluish grey sandy clay (Chama Bed). Conus scabriculus. 
53 Feet. 
fae 4. Grey and brown stiff clays, with well-preserved marine fossils, including 
38 [tie large Hippochrenes amplus. Chrysodomus lima. (Fusus.) 
= 8 15. Dark sandy clays with glauconite and abundant marine fauna. Rare 
ts Gane: remains, 
49 Feet. 
6. Grey clays with sand drifts and pockets containing a large number (400 
# ¢ |species) of minute well-preserved shells. Rare examples of the teeth of 
E = Carcharodon auriculatus occur in the higher beds. Canarium. bartonense. 
a ss |7. Dark glauconitic clay with fir-cones (Pityostrobus dixoni) and fragments 
of Chelonia (Nummulites elegans Zone). 
8. Band of rolled flint pebbles in buff sand. Casts of bivalves, &c., in 
whitish sand (Bracklesham Beds ?) 
The effect of a gentle dip of the strata te the east, or rather south-east, is to bring 
down successive fossiliferous zones to the level of the shore, and we observe that those 
which contain layers of Septaria maintain a shelf fronting the sea, while others are 
constantly giving way and breaking up through the action of rainwater or frost, so 
that a good deal of the succession is confused in places. 
Denudation proceeds at a rapid rate on this part of the Hampshire coast, and the 
rate of recession cannot be much less than 2 feet per annum. ‘The average may be 
slightly under this estimate, taking the line of cliffs as a whole, yet there is abundant 
evidence of great changes effected in recent years. The whole of the cliff side laid out 
as pleasure grounds below the former Barton Court Hotel suddenly founderéd. It 
was carried bodily forward towards the sea, and the pathways, &c., were destroyed. 
So great was the erosion that it became necessary to pull down part of the hotel 
buildings, while private attempts to drain and preserve the cliffs further west, near 
Highcliff, have repeatedly failed. ; 
The denudation in past ages which led to the removal of so great a portion of the 
Tertiary strata, following on the destruction of the Chalk barrier to the south, permitted 
the formation of Christchurch Bay and Bournemouth, or Poole Bay, and also deepened 
the waters of the Solent. There is little room to doubt that the erosion of Eocene 
strata has been very great since the breach was made between the chalk cliffs near 
Swanage in Dorset, and the western extremity of the Isle of Wight. Hengistbury Head, — 
on the western flank of Christchurch Bay, has nevertheless retarded the progress of 
erosion, by reason of the ironstone concretions encountered in the cliff, aided by the 
“ieee Sate 
oe eee re 
