Makshall. —Magnesia/it Bocks at Milford Sound. 481 



Length, 17 mm.; width, 19 mm.; thickness, 13 mm. 



Locality. — Broken Kiver. 



Easily distinguished from the last by its finer and more 

 numerous ribs. I have seen very large fossil specimens from 

 Patagonia. It is still living south of Kerguelen Island, 



EXPLANATION OF PLATES. 

 Plate XLV. 

 Fig. 1. Tercbratula conccntrica , Broken River. 

 Fig. 2. Magellania lenticularis, var. ovalis, Wanganui. 

 Fig. 3. Magellania novara, Weka Pass district. 

 Fig. 4. Magellania parki, Oamaru. 

 Fig. 5. Magellania' msolita, Duntroon. 



Plate XL VI. 

 Fig. 1. Magellania sufflata, Canterbury. 

 Fig. 2. Terebrarella radiata, Broken River. 

 Fig. 3. Tcrebratella neglecta, Curiosity Shop. 

 Fig. 4. Tcrebratella gaulteri, Curiosity Shop. 

 Fig. 5. Tcrebratella gaulteri, Cobden limestone. 

 Fig. 6. Bouchardia tapirina, Curiosity Shop. 

 Fig. 7. BoucJiardia rhizoida, Weka Pass district. 



Art. LIU. — Magncsian Bocks at Milford Sound. 



By Dr. P. Marshall. 



[Read befoie the Otago Institute, 13th September, 1904.] 



Plate XL VII. 



The remarkably wide occurrence of magnesian rocks in New 



Zealand has often been remarked upon. The well-known 



Dun Mountain region was described by Hochstetter in 1865. 



In 1887 the reports of the Geological Survey of New Zealand 



contained a paper by Professor Park on the Big Bay district, 



where a very large mass of these rocks constitutes the Red 



Hill Eange and some neighbouring portions of the coastal 



regions. This district was more fully described by the late 



Professor Ulrich in the Quarterly Journal of the Geological 



Society of 1890, when the occurrence of the nickel-iron alloy 



awaruite in these rocks was first mentioned. 



A small occurrence of these rocks, hitherto only briefly 

 referred to in Hutton's " Geology of Otago," has long been 

 known to exist at Milford Sound, but beyond the fact that 

 bowenite was found there little more has been known. A 

 recent visit to Anita Bay, at the entrance to Milford Sound, 

 enabled the author to make a cursory examination of the 

 district, and bring away specimens for microscopical and 

 chemical investigation. 



At the east end of the bay there is a large outcrop of 

 gneissic granuhte, much contorted. A small beach separates 

 this from a- mass of dunite about 150 ft. wide, striking ap- 

 parently S. 80° W., and dipping 70° S. The dunite is per- 



31— Trans. 



