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regular hill face running north- west and south-east. The hills on the western 

 side of both bays also present an equally regular slope running in the same 

 direction. The distance between these two ridges is about half a mile, and 

 the space intervening between the waters at the heads of Lyall's and Evans' 

 Bays is occupied by a boulder bank and sand-dunes, about a mile or a mile 

 and a quarter in width. The boulder bank lies in the middle of this space, 

 and forms a ridge sloping from a summit towards both bays — the summit 

 being slightly higher than the general level of the sand-dunes on either side of 

 it. Between the boulder bank and the water line in each of the bays, lie 

 these sand-dunes, composed of ordinary siliceous sea sand, here and there 

 clothed with the vegetation usual to such habitats. The stones composing the 

 boulder bank are chiefly sandstones, varying much in size and hardness, and in 

 some instances intersected with little veins of quartz. 



Now you are aware that the prevalent winds here are north-west and south- 

 east, and blowing as they frequently do with considerable force through the 

 opening between Evans' and Lyall's Bays, they are constantly carrying the sand of 

 the dunes from one side of the boulder bank to the other. The motion of drift- 

 sand is by a succession of jumps along the surface of the ground, and, strange 

 as it may seem, it is the cutting action of the sand in its passage over the 

 boulder bank which produces these stones. This is evident from an examina- 

 tion of the series of specimens before you, and becomes the more so when they 

 are seen in the locality indicated. The action of drift-sand in cutting rock has 

 long been observed, and, indeed, in the Museum you have many specimens 

 illustrative of this action, but in no instance that I am aware of, has it been 

 noticed as producing results of so remarkable a character, as those which I 

 have so imperfectly brought before you. 



The cutting action of drift sand has received much attention from geolo- 

 gists and engineers engaged in examining the line of the great Bacific railway, 

 and it would be interesting to ascertain whether anything of the same kind had 

 been observed by them. 



