one time there was a small quantity only of material of the grades mentioned though all the while material was passing rapidly from a coarser to a finer state past this intermediate size. The gradually increasing fineness of grade as the water becomes deeper and deeper is most striking (Table 13, Nos. 5–17, but omitting No. 10 which is close to the breakwater and subject to unusual conditions of wave action for such a depth). It is at once apparent that there is a grading appropriate in its smallest details to the intensity of the wave disturbance which in its turn is directly dependent upon the depth of the water. The practical elimination of 0.250 — 0.177mm. grade in deeper water is most marked while the grade 0.149 — 0.074 mm. at first increases uniformly until it reaches a maximum of over 80 per cent; but at that point the increase of the material finer than 0.074 is such that the coarser material has to decrease in sympathy. It was interesting to notice that except for a few dead shells there were no organic remains at less depths than nine fathoms but in the two dredgings of greater depth there was an abundance of specimens of marine worms and of small species of Nucula. This seems to prove that at all depths less than nine fathoms the bottom is shifting but is stable when the depth is greater. This is somewhat surprising as it would be expected that wave action would be rather disturbing at such a depth. From the accepted formulae it would appear that with a swell five feet high and wave length of 1,000 feet there would be an oscillating movement of 0.3 feet per second on the sea floor. That the material is easily moved by water disturbance is proved by an observation made when the steamer Port Curtis was being anchored in seven fathoms of water. The vessel was drawing 22 feet and in order to stop her way the propellor was put at full speed astern. The movement of the water stirred up the bottom and from the water that rose to the surface a deposit was obtained that had practically the grading of the sea floor in all of its details, though 25 feet intervened between the bottom and the blade of the revolving propellor. The finest sand from 10 fathoms is not quite as fine as the material of the thick Tertiary sandstone formation which has such a wide distribution at Lake Waikare Moana and occurs generally on the flanks of the mountain range of Hawkes Bay. The grading of this sandstone is given in Table 2, No. A. It is also very similar to the deposit left by a heavy flood on the banks of the Wairoa River. This material was derived from the Tertiary rocks which consist of fine sandstones and shales. (Table 2, C). Relation Between The Slope Of A Beach And The Size Of Component Particless. It is a matter of common observation that those beaches that are composed of gravel are steeper than those that are formed of sand. Actual statements of the slope of beaches are however hard to find. The only measurements made so far are of the Napier beach of fine gravel and the Cape Farewell beach of fine sand. Both are fully exposed to heavy seas. The former when measured had an average slope of 6 ½ degrees, the latter of 1 degree only.