F. R. C. Reed — Eocene of Hengistbury Head. 101 



It only remains to add that, since planning this paper, I have 

 found that my explanation is not altogether original. It has 

 substantially been given by Seeley, as follows: "As new matter 

 is aggrej>ated to the outside, it is soft, and consists more of clay 

 than of carbonate of lime. Afterwards the carbonate of lime 

 becomes infiltrated into the outer clayey layer, and enters into 

 crystalline combination, so as to expand the outer layer more than 

 the internal part. This splits the concretion internally but not 

 externally, and thus, as the whole mass enlarges, the system of 

 internal cracks also becomes better developed " (Phillips's Manual of 

 Geology, pt. i, edited by H. G. Seeley, p. 103). 



As this passage does not seem to have attracted attention, and the 

 Manual has long been out of print, the present paper seems justifiable. 



III. — Note on^ the Eocene Beds of Hengistbury Head. 



By F. R. CowPER Reed, M.A., F.G.S. 



niHE succession of the Eocene beds exposed on Hengistbury Head, 

 X near Christchurch, vs^as described in some detail by Mr. J. S. 

 Gardner in 1879.^ Four divisions were recognized by him, and they 

 were termed in descending order (1) the Highcliff Sands, (2) (3) the 

 Upper and Lower Hengistbury Head Beds, and (4) the Boscombe 

 Sands. No list of fossils from any of these divisions appears to have 

 been published, but on the Survey Map, Sheet 16, the following 

 fossils are mentioned in the beds of Hengistbury Head, though no 

 precise horizon is given : — 



Cardmm semigranidatuvi. 



Cytherea obliqua. 



Solen affinis. 



Thracia sp. 



Lamna elegans. 



Otodus appendiculatus. 



Leaves of Dicotyledonous plants. 



Prestwich" mentioned a Modiola, and Mr. Gardner records " a few 

 casts of bivalves " from the lower part of the Hengistbury Head Beds 

 (without giving any generic determinations), as well as sharks' teeth 

 from the ironstones. 



During a recent brief visit to the headland a considerable number 

 of fossils were collected by me in the clays between the two upper 

 bands of ironstone concretions exposed in the large quarry on the 

 Head. The upper band of ironstone concretions is here about 

 5-6 feet below the base of the High cliff Sands which cap the sides 

 of the quarry, and it was in tlie lower part of the 6 feet of buff or 

 pale chocolate-coloured sandy clays which lie between this band and 

 the second band of ironstone nodules that the fossils were found. 

 Nearly all of them are in the state of casts and are difficult to 

 extract whole, so that their determination is sometimes difficult or 



' Gardner, Q.J.G.S., vol. xxxv, p. 209, 1879. 

 " Prestwich, Q.J.G.S., vol. v, p. 43, 1848. 



