Vol. 62.] GEOLOGY OP DUNEDIN (NEW ZEALAND). 423 



The spberulitic structure in the tinguaite of Hooper's Inlet he ascribes to 

 zeolitization, especially the formation of natrolite. 



The spherulitic structure of the Blueskin phonolite is cousidered by him 

 as very remarkable and exceptional. 



In most other essential respects he approves of the classification 

 that I have adopted, so far as he has been able to judge from 

 the rock-slices sent him — that is, in all those instances concerning 

 which I was in doubt. — P. 31., November 15th, 1905J] 



EXPLANATION OF PLATES XXXVI-XXXIX. 



[The numbers B 165, etc., in Pis. XXXVII-XXXIX are those of the 

 microscope-slides preserved in the author's collection.] 



Plate XXXVI. 



Geological map of the neighbourhood of Dunedin, on the scale 

 of 2 miles to the inch. 



Plate XXXVII. 



Fig. 1. B 165. Foyaite ; Harbour Cone. Crystal of amphibole largely resorbed, 

 with a rim of pyrites and segirine and inclusions of apatite. It is sur- 

 rounded by decomposed felspar. X 45 diameters. 

 2. B 22. Tinguaite ; Limekilns, Otago Peninsula. Large crystal of 

 nepheline, embedded in a ground mass of nepheline-, segirine-, and 

 anorthoclase-microliths. x 45 diameters. 



Plate XXXVIII. 



Fig. 1. C 4. Tinguaite ; Hooper's Inlet. Besorbed amphibole, replaced 

 by aegirine and analcite. Groundmass of felspar and nepheline. 

 X 45 diameters. 

 2. C75- 'Analcite-rock.' Camptonite showing camptonitic structure. 

 Crystals of amphibole in a groundmass of analcite and felspar. X 45 

 diameters. 



Plate XXXIX. 



Fig. 1. C6. ' Analcite-rock ' (camptonite). Bounded grain of pink pyroxene 

 surrounded by amphibole. Groundmass of amphibole, analcite, and 

 felspar. X 45 diameters. 

 2. C 183. Kaiwekite ; Xaikorai Valley. Large crystal of anorthoclase 

 embedded in a groundmass of isometric felspars and felspar-laths. 

 X 45 diameters. 



Discussion. 



The Chairman (Mr. B,. S. Herries) congratulated the Society on 

 the presence of such an old and valued Fellow as Capt. Hutton, whose 

 last appearance at one of their meetings had been at Somerset 

 House, in the days of Lyell and Murchison. On behalf of the Society 

 he welcomed him back to England, and thought that the Fellows 

 were much indebted to him fox the able way in which he had 

 presented this very interesting paper. Although he (the Chairman) 

 had visited New Zealand, he had not been so far south as Otago, and 

 in the districts that he had seen (those of Aucklaud, the Waikato, the 

 Hot Lakes, the Otira Gorge, etc.) he had paid more attention to the 

 physiographical conditions than to the rocks. He had, however, noted 



