4 Observations on Sand-dunes. 



several bone spikes or needles, relics of the past tribes of the 

 Cape. At about the same distance from the lighthouse, in a 

 mixture of beach material, pebbles, humus, and broken 

 shells, resting on the Carbonaceous sandstone forming the 

 high cliffs of the cape, and apparently intermediate between 

 it and the overlying dunes, I, in company with Mr. H. Ford, 

 obtained a similar bone spike, with numerous seal bones, a 

 ramus of the lower jaw, pieces of vertebrae, bones of the 

 limbs, and a few pieces of ribs, whilst the shells appeared to 

 be those existing on the coast at the present day. 



Both at the Cape and along the South Australian coast 

 peculiar concretions are to be met with in the dunes, often 

 assuming fantastic shapes and forms, generally resembling 

 trees with their branches. Indeed, for such they have fre- 

 quently been taken ; for, amongst others, Mr. T. Burr 

 describes calcified stems of trees standing in the position of 

 their growth in the sand-dunes of St. Vincent's Gulf, near 

 Adelaide* The same phenomena were likewise noticed by 

 the late Professor Jukes at the entrance of the Swan River, 

 Western Australia. t Along that coast, hills 200 to 300 feet 

 high, forming districts stretching as much as ten miles 

 inland, are formed of once drifted sand, now consolidated, and 

 supporting a good forest vegetation. This deposit consists 

 chiefly of fragmentary shells solidified into a compact stone, 

 sufficiently hard for building purposes. Scattered plentifully 

 through such material, Professor Jukes saw similar pipe and 

 tree-like concretions, often ending downwards in tapering 

 forms like stalagmites. According to the Rev. J. E. T. Woods, 

 these " pseudo trees " are composed of a magnesian lime- 

 stone, j 



On comparing the sand-dunes of the British coasts we 

 find nothing to equal those of the coasts of Australia, although 

 Sir C. Lyell has placed on record a rather interesting case of 

 the shifting nature of sand, which may be of interest. All 

 that now remains of the ancient village of Eccles, on the 

 coast of Norfolk, is the ruined tower of the once considerable 

 chapel, which, extant in 1605 A.D., was in 1839 almost com- 

 pletely buried in large dunes, locally called " Marrams." 

 The action of the wind between this and 1862, a space of 

 23 years, was such that at that date the foundations of the 

 edifice were exposed, and the surrounding dunes almost 



* Inst. Jour. Geol. Soc, xvi. 



t Manual of Geology, 1862, p. 155. 



I Geol. Observations, 1862, p. 168, 



