208 T. Thompson — Discovery of Hippopotamus, 8fc. 



the skull and horn-cores of Bison prisons in 1867. It will be ob- 

 served that the upper layers of the Drift are totally distinct in 

 character from this, being such as might be attributed to the rapid 

 action of a series of floods sufficiently violent to silt up the Post- 

 pliocene river-bed. The component materials are almost exclusively 

 derived from the adjoining Green Sandstone formation ; the only 

 exception being that the Blue clay mentioned as occupying a middle 

 position appears to be the surrounding Kimmeridge clay altered by 

 water action. The deposit is on tlie side of Hawkers' Hill, 

 towards the far higher elevation of Green Sandstone and Gault on 

 which Shaftesbury stands. The portion hitherto dug out is nearly 

 200 feet long, consisting, at its commencement on the hill side, of 

 the old river bed, but slightly marked at first, with perhaps one 

 foot of the loose sandy strata above it. Partly by the rise of the hill 

 and partly by a slight dip of the river-bed in the contrary direction, 

 the final thickness is increased to about 10 feet. The width excavated 

 is only some 12 feel. We are here evidently at one margin of the 

 Post-pliocene river, the Drift coming to an end against an abrupt 

 bank of undisturbed Kimmeridge clay 10 feet high (see Section 3). 



The surface of the hill is perfectly uniform, looking as exclusively 

 Kimmeridgian as the seven or eight miles of that formation which stretch 

 from it westward across the low lands. It will be understood that 

 Shaftesbury hill is a high eminence composed of Upper Green Sandstone 

 resting on Gault, and is separated from Hawker's Hill by a valley of 

 gentle declivity. The Gault crops out some 600 yards from the Drift, 

 and is succeeded on the steep hillside by Green Sandstone, like that 

 from which the materials for the latter were derived. As regards 

 the general configuration of the country, it seems hopeless to con- 

 jecture how the river could ever have flowed where its indelible traces 

 still remain. Under present circumstances, it would be a physical 

 impossibility. Is' or is there any existing river in any direction for 

 some miles. It should be added that most anxious search was made 

 for any shells that might aid in determining the climate probably 

 prevailing when the Drift was deposited, but the only acquisition 

 was one battered and flattened snail shell — either Helix arbustorum 

 or nemoralis. No flint implements or human relics of any kind have 

 been found in this deposit. 



The writer is indebted to Dr. Blackmore, of Salisbury, for 

 his kindness in making a careful examination of the remains dis- 

 covered, and is permitted to quote his valuable authority for the cor- 

 rectness of the names assigned them. It is Dr. B.'s opinion that 

 there are indications of at least three individuals of Jjison priscus. 



The writer will be happy to answer to the best of his ability any 

 communications that may be addressed to him on this subject. 



GiLLINGHAM, DOKSET. 



V. — The Discovert of Diamonds at the Cape of Good Hope. 

 By "W. GuYBON Atherstone, M.D., F.G.S., of Graham's Town, Cape of Good Hope. 



IN the Geological Magazine of December, 1868, appears an article 

 on this subject by Mr. J. E. Gregory, declaring the whole story 



