UPPER EOCENE FORMATIONS. 
257 
withstanding the intervention of the St. Helen’s series. The 
white and green marls of the Headon series, and some of the 
accompanying limestones, often resemble the Eocene strata 
of France in mineral character and color in so striking a 
manner as to suggest the idea that the sediment was derived 
from the same region or produced contemporaneously under 
very similar geographical circumstances. 
At Brockenhurst, near Lyndhurst, in the New Forest, ma¬ 
rine strata have recently been found containing fifty-nine 
shells, of which many have been described by Mr. Edwards. 
These beds rest on the Lower Headon, and are considered as 
the equivalent of the middle part of the Headon series, many 
of the shells being common to the brackish-water or Middle 
Headon beds of Colwell and White- 
cliff Bays, such as Cancellaria mu- 
ricata^ Fusus lahiatus^^ow,^ 
etc. In these beds at Brocken¬ 
hurst, corals, ably described by Dr. 
Duncan, have recently been found 
in abundance and perfection ; see 
Fig. 180, Solenastrcea cellulosa. 
Baron Von Konen* has pointed 
out that no less than forty-six out 
of the fifty-nine Brockenhurst shells, 
or a proportion of 78 per cent., agree 
with species occurring in Dumont’s 
Lower Tongrian formation in Belgium. This being the case, 
we might fairly expect that if we had a marine equivalent 
of the Bembridge series or of the contemporaneous Paris 
gypsum, we should find it to contain a still greater number 
of shells common to the Tongrian beds of Belgium, but the 
exact correlation of these fresh-water groups of France, Bel¬ 
gium, and Britain has not yet been fully made out. It is 
possible that the Tongrian of Dumont may be newer than 
the Bembridge series, and therefore referable to the Lower 
Miocene. If ever the whole series should be complete, we 
must be prepared to find the marine equivalent of the Bem¬ 
bridge beds, or the uppermost Eocene, passing by impercepti¬ 
ble shades into the inferior beds of the overlying Miocene 
strata. 
Among the fossils found in the Middle Headon are Cythe- 
rea hicrassata and Cerithium pUcatum (Fig. 160, p. 245). 
These shells, especially the latter, are very characteristic of 
the Lower Miocene, and their occurrence in the Headon se¬ 
ries has been cited as an objection to the line proposed to be 
* Quart. Geol. Journal, vol. xx., p. 97. 1864. 
