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for analysis, whereupon it was found to be a" rich rock phosphate, containing phosphoric! acid equivalent to 71 per cent, of phosphate of 1909 a sample of limestone from the Onewhero district was found to contain 4-855 per cent, of phosphoric acid, equivalent to 10-60 per cent, of phosphate of lime.f Such material, if present in quantity, would have considerable value as a fertilizer. The only preparation required before application to the land would be to grind it to a powder. General Geology of Country examined. The sedimentary rocks of the North. Auckland Peninsula fall into three groups, one probably of Early Mesozoic, one of Cretaceous, and one of Tertiary age. Igneous rocks of various types and ages have a wide distribution, but seeing that they are nowhere of a character resembling the apatite-bearing rocks of Quebec Province, Canada, phosphate-deposits need not be expected to occur in association with them. Since phosphate of lime is commonly associated with limestone, calcareous rocks are of the most importance in connection with the search for that substance. In North Auckland, according to Professor Park, the Cretaceous rocks include two limestones —the " Whangarei limestone " and the " hydraulic limestone." The former is a hard crystalline rock containing, as a rule, a very high percentage of carbonate of lime, whilst the latter is a soft, impure, argillaceous limestone, of great value as a material for cement-manufacture. Both classes of rOck are typically seen near Whangarei—the Whangarei limestone at the Abbey Rocks and at To Waro, near Hikurangi ; the hydraulic limestone at Limestone Island and at M'angapai. Thick beds of the last-named rock appear near Warkworth and in other localities, but very commonly it is in thin bands of a lenticular character interbedded with claystone, as at Kaipara Flats, Maungaturoto, and many other localities. Greensands sometimes contain phosphatic; concretions in sufficient quantity to form deposits of economic importance, and therefore the greensands of various localities in North Auckland deserve some investigation. Another rock that may be|associated with phosphate-deposits is the so-called firestone—a hard flinty rock, in places present in continuous bands, as at Snell's Beach, east of Mahurangi (Warkworth) Harbour, but more commonly occurring as concretions. In the Onewhero district the chief rocks are Miocene claystones and a soft, impure, sandy limestone. At the township and for some distance around, especially to the north and north-east, these rocks are capped by volcanic debris, which has formed a deep clay-loam soil of fertile character. Data obtained. Kaipara Flats District. —About 20 chains north of Kaipara Flats Railway-station is a cutting where much-broken calcareous claystone of probable Cretaceous age is exposed. Impure hydraulic limestone and a dark flinty concretion from this cutting were analysed in the Dominion Laboratory, and found to contain only a very small percentage of phosphoric anhydride (or phosphoric acid). A sample of hydraulic limestone from Williams's farm (collected by Dr. J. Henderson in July, 1913) on being powdered and treated with nitric acid yielded a solution that with, ammonium molybdate gave a small precipitate, indicating that phosphoric anhydride was present only in the ordinary small amount (probably about 0.1 per cent.). Warkworth District. No indication of phosphate was seen during the writer's brief visit. The firestones of Snell's Beach, which may possibly be associated with some phosphate, were not examined, owing to lack of time. They were, however, visited by Dr. Henderson in July, 1913, when no unusual characters were observed. Maungaturoto District.- --Two samples of impure limestone —one of hydraulic character, the other hard and probably magnesian—were obtained from the neighbourhood of the railway-line now under construction. These were found to contain phosphoric anhydride in ordinary amount only —namely, 0-10 and 0-14 per cent- respectively. Nothing appearing to have the characters of phosphate rock was seen near Maungaturoto or in the direction of Paparoa, which was also visited. Whangarei District. —Under the guidance of Major G. Clark-Walker, who has discovered specimens of phosphate rock in several, localities, the writer visited Otaika and Tikorangi (near Mangapai). A mixed sample, mainly of hard, more or less flinty, rock collected on the roadside near Mr. Dwyer's house, Otaika, when analysed yielded only o'lo per cent, of phosphoric anhydride. A few yards away, however, inside a gate, the writer collected a sample of soft pale-brown to cream-coloured porous rock that on analysis was found to contain 24'40 per cent, of phosphoric anhydride (equal to 53-31 per cent, of tricalcic phosphate). The specimen was broken from a small boulder on the surface. The underlying rock was not to be seen, owing to the somewhat thick covering of soil and subsoil. On the roadside near Tikorangi Hill is a small excavation, where Major Clark-Walker some years ago found a lump of high-grade phosphate rock weighing about 1.6 lb. A mixed sample of claystone and other material taken here gave on analysis only 0-10 per cent, of phosphoric anhydride. The overlying clay was even lower in its phosphoric-anhydride content, and material collected on the road was little better, so that evidently there is here no phosphate-deposit. J Between the spot last mentioned and an old limestone-quarry nearer Whangarei a sample from various hard but narrow bands seaming the claystone exposed in the road-cuttings was taken. On analysis this yielded 0-32 per cent, of phosphoric anhydride, equivalent to 0-70 per cent, of tricalcic phosphate. Samples of greyish fine-grained limestone and of the prevailing white crystalline limestone from the Abbey Rocks contained 0-20 per cent, and 0-11 per cent, of phosphoric anhydride respectively.

* Dom. Lab. Rep. No. 38, 1905, pp. 9-10. fDom. Lab. Rep. No. 43, 1910, p. 13. P a 0 6 calculated by writer from percentage of triealeie phosphate. J The same locality has also been examined by Mr. B. C. Aston vrith similar results. See " Rock Phosphate inNew Zealand," tho Journal of Agriculture, vol. x, No. 6,_lst June, 1915, p. 501.