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rather close texture, in others they are irregular in shape, looser in 
texture, and more sandy, and in these masses some of the bones occur ; 
other bones are lying in the sandy material which is the matrix of all the 
concretions and boulders. The silicified wood occurs both in the loose 
calcareous concretions and in the sandy clay. The bones in the concre- 
tions are calcified, and the hollow interior is lined with calcite crystals. 
Many bones in the sandy matrix are in a similar condition, but some of 
them in this position are free from any noticeable deposit of carbonate of 
lime. The matrix near, the bottom of the well is very like the material 
above, perhaps rather more clayey. An examination of the calcareous 
grit in which the concretion and bones lie was made by dissolving as 
much as possible in dilute hydrochloric acid, washing off the considerable 
quantity of clayey material, and looking at the remainder under the 
microscope. Eliminating the grit of quartz and felspar a millimetre or 
over in diameter, the smaller fragments consist of quartz, microcline, and 
perthite, usually sharp-edged and very little weathered, and small lumps 
of opaque clayey stuff which break down into indeterminable dust. The 
smaller clayey pellets in the pale matrix of the rock consist of clay and 
grains of quartz and felspar without an appreciable quantity of carbonate 
of lime. The only difference I could detect in the last 10 feet and what 
lies above is due to the presence of the thin layers of fibrous calcite, con- 
cretions, wood, bones, and large fragments of bed-rock. The siliceous 
concretions are traversed by cracks lined with small crystals of quartz, 
sometimes arranged in a roughly radial manner rather like the cracks in 
calcareous " septarian " nodules from clays and shales. 
There were two tunnels at the bottom of the well, each about 6 feet 
high, one was 30 feet long and the other 10 feet. The walls and roof of 
these presented an appearance similar to that of the corresponding part 
of the well. The longer tunnel has since been extended to the east side 
of the valley, where the gneiss was exposed. 
The whole of the deposit appeared to be the result of the gradual 
fining in of the valley by local debris at a time when the rainfall no longer 
sufficed to keep the stream-bed free of detritus. At the time of my first 
visit no teeth had been found, and the fragments of bone, some of which 
were taken from the dump or had been brought to O'okiep, while others I 
extracted from the wall of the well and tunnels, did not fit together to 
make one complete bone. Mr. Coetzee said he would keep all fragments 
found till I could go there again. At the time it seemed that the bones 
might belong to a large buck, but on a second visit, in 1914, when the 
geological survey was extended to that area, Mr. Coetzee gave me a tooth 
which looked as if it were dinosaurian." On this occasion there was 
* Dr. Smith Woodward, to whom a cast of the tooth was sent, says it undeniably 
belongs to a herbivorous dinosaur. 
