914 J. S. GARDNER—DESCRIPTION AND 
point, the watch-house, are 25 feet thick. In various places sections 
are exposed, as at the N. corner of the Head, where under 3 feet of 
peat we see 12 feet brown and yellow sand; yellowish sand with 
four thin layers of pipeclay, 2 feet 5 inches ; white sand shading to 
orange, 1 foot 3 inches ; deep orange-mottled clayey sand, 11 inches, 
resting upon brownish sandy clay with septaria. At the S.H. 
corner we notice 6 feet whitish sand shading to orange, with 1 foot 
9 inches orange sandy clay at base. The 8.H. extremity presents a 
good section of the white sands :— 
ft. im. 
Hich White sand with a few yellow bands .................2s0000- (280 
ice Hard: whitesan deesereeeen cere eeepencesatencsnare se o-s Masa it © 
es A Yellowish and orange clayey sand...............00seeeeeeeee 14: 
Sands. | Hard white sand ((lcealijpatiel)) reeeretes- seekers sees eee Le 10 
Heng- ( Dark clays and light sand in irregular layers ............... 1 9 
istbury- } Hard white sand (local patch) ...........-.12-s1se-seeeeeee eee 3.3 
Head ) Brownish sandy clay with iromstone................s.ceceeeees 44 0 
Beds. | Débris concealing 12-feet bed of greensand. 
The white sands are 30 feet thick at Highcliff, having thinned out 
from 42 feet at Alum Bay, and are therefore probably originally even 
less in thickness here. At Alum Bay and at the Head the junction 
or base bed is strongly ochreous in colour. 
Hengistbury-Head Bed.—The next stratum does not, so far as 
the coast-line of the mainland is concerned, extend beyond the 
Head itself. It is composed of brownish-drab, laminated, sandy 
loam, about 45 feet thick, with from 3 to 5 nearly parallel layers of 
large tabular ironstone * concretions. It is well exposed on the 
S.W. and §8.E. sides, and in an extensive quarry which nearly 
cuts the headland in two, E. and W. ‘These septaria are con- 
spicuous objects in the cliffs and form a reef running out to sea. 
They sometimes contain sharks’ teeth, of both the Otodus and 
Lamna type, and vertebrae. Frequently, also, compressed tree-stems 
of considerable size traverse them; one of these, according to Sir C. 
Lyell, measured 4 x 23 feet with 4 in. of bark like black shining coal ; 
I have measured others 5 feet in length, but not so wide. All the 
wood is riddled with Teredo-borings of large size. Prof. Prestwich 
records the occurrence of seeds in the septaria; but I have looked 
in vain for them, although layers of washed and fragmentary lig- 
nitic matter are not unfrequent. Itis probable that the dicoty- 
ledonous leaves in the list of fossils from Hengistbury Head on the 
Geological Survey map were from this stratum ; since although I have 
failed to discover any trace of such here, I have found a tolerably 
perfect leaf at St. Catharine’s Hill in the same beds further inland. 
The four bivalve shells in the same list are probably, like the Modiola 
found by Prestwich “in the lower part of the clay,” from the green- 
sand next described, in which I some years ago met with a few 
casts of bivalves. 
Succeeding the 45 feet of ironstone-bearing sandy clay, and at 
about 7 feet 6 inches below the bottom line of nodules, is a distinct 
* Mr. Tylor, Quart. Journ. Geol. Soe. vol. vi. p. 138, gives a brief account of 
these blocks. 
