Geological Society of London. 377 



occurred on the surface of tlie Lower Greensand, and to a small 

 extent on the Weald Clay. A block of granite, weighing between 

 5 and 6 lbs., M'as found on the chalk escarpment at Kilhurst Hill. 



The angular flint-drift occurred mainly on the higher parts of the 

 area, and was wanting in the river-valleys, where, however, river- 

 gravels derived from the denudation of the older deposits were abun- 

 <iantly developed. This distribution of the angular drift was shown 

 to be incompatible with the theory of its origin advocated by Sir R. 

 Murchison and some other geologists, who attributed it to a violent 

 and transitory current. The author showed that not only in the 

 Wealden area, but throughout many of the neighbouring districts, 

 the angular drift consisted of the undenuded remnants of a deposit 

 formed before the present river-valleys were cut, and that many of 

 the river-gravels, though newer than the angular drift, were 

 deposited when the valleys had been less excavated than they now 

 are. This was Mr. Topley's view with respect to the northern 

 portion of the Wealden area. Mr. Searles V. Wood's marine theory 

 of the origin of these gravels was discussed, and shown to be refuted 

 by their mode of occurrence. It was, moreover, contended that the 

 drift, although composed of local materials, was probably of sub- 

 aqueous origin, and not merely subaerial. The discovery of a granite 

 boulder might, if confirmed by other discoveries, lead to a modifica- 

 tion of the views generally held as to the physical character of the 

 area during the Glacial period. 



8. '■' Report on Palseo-botanical Investigations of the Tertiary 

 Flora of Australia." By. Dr. Constantin Baron von Ettingshausen, 

 For.Corr.G.S. (This paper appears in full in this Magazine.) 



9. " On some new Features in PelanecMmts corallinus." By T. 

 T. Groom, Esq. Communicated by Prof. T. M'Kenny Hughes, M.A., 



F.G.S. 



The discovery by the author, in the Coral Rag at Calne, of an 

 additional and well-preserved specimen of the Echinoderm originally 

 described by Dr. Wright as a Semipedina, but subsequently made 

 the type of a new genus, PelanecMnus, by Mr. Walter Keeping, 

 afforded an opportunity of adding considerably to the known 

 characters of the type. The test proved to be flexible, as in the 

 Echinothuridge, a point already noted by Mr. Keeping. 



A number of details as to the interambulacral and ambulacral 

 areas, the imbricating peristomial plates, pedicellaria3, and teeth 

 were given. Pedicellarige did not appear to have been previously 

 observed in fossils. 



The genus appeared to occupy an intermediate position between 

 the Echinothuridee, Echinidas, and Diadematidte, and must form the 

 type of a distinct subfamily, perhaps referable to the last named. A 

 new description of the species was added. 



10. " On Boulders found in Seams of Coal." By John Spencer, 

 Esq., F.G.S. 



The discovery of a boulder weighing 6 lbs., and composed of 



