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J. D. ENTS OH" SAND-WORN STONES FROM NEW ZEALAND. 



8. On Sand-worn Stones from New Zealand. 

 By J. D. Enys, Esq., F.G.S. (Bead April 11, 1877.) 



Before describing the Eolian or wind-worn stones, specimens of 

 which are exhibited, I will give a short description of the locality 

 from which they come. On the western side of the entrance to the 

 Harbour of Wellington (situated on Cook's Straits, at the southern 

 end of the North Island of New Zealand) is a peninsula attached to the 

 mainland by an isthmus which has only a slight rise above the sea. 

 This peninsula runs parallel to the mainland for two or three 

 miles ; and the connecting isthmus is about a mile across, dividing this 

 space unevenly into two bays, which are known as Evans Bay 

 and Lyells Bay. 



On each side of the isthmus is a line of low sand hills; and 

 between them is situated a flat piece of sand which is mixed with 

 sufficient clay to form a hard bottom. On this rest the stones which 

 are the subject of this paper. 



Fig. 1. — Sand-worn Stone 

 showing an early stage of 

 Eolian action. (Half 

 natural size.) 



Fig. 2. — Sand-worn Stone 

 showing completed Eolian 

 action. (Half natural 

 size.) 



From the ground on both sides of these bays being of considerable 

 height and lying north-west and south-east, the prevailing winds, 

 which blow from the same directions with great force, drive a cloud 

 of siliceous sand from one set of sand dunes to the other. This sand, 

 on a windy day, forms a dense mass reaching to about the knees of 

 any one walking over the ground. The result of this is the gradual 



