170 Transactions. — Geology. 



covered by marine rocks, which culminated in a hmestone, 

 well known as a building-stone, in many parts of New Zea- 

 land. This stone, under various names, is found in patches 

 all round the coasts of New Zealand, from Wiuton in the 

 south to the Bay of Islands in the north, as well as in many 

 of the inland valleys. It belongs to that variety called poly- 

 zoal limestone, . because it is made up principally of small 

 fragments of calcareous Polyzoa, &c. ; and it is, no doubt, the 

 remains of a reef which in the Ohgocene period encircled New 

 Zealand. These Tertiary rocks lie unconformably on those of 

 the Waipara system at the Weka Pass, Mount Somers, and a 

 few other places ; but elsewhere they lie upon older rocks, 

 belonging to the Hokanui and other systems. At the time of 

 the formation of the Oamaru limestone there were living in 

 our seas a Zeuglodont whale {Kekenodon onamata), as well as 

 true cetaceans {Squalodo,i serratus), a penguin {Palceeudyjites 

 antarcticus) , the huge shark (Carcharodoii ang list id ens), rays 

 (Trygon and Myliohates), and a sparoid fish {Sargus laticonus), 

 as well as the nautilus called Aturia australis. But with them 

 are found some Cretaceous-looking Echinoderms belonging to 

 the genus Holaster. These last were no doubt survivors from 

 Mesozoic times, and I agree with Dr. Stache and Sir F. 

 McCoy in thinking that the rocks in which they occur belong 

 to the Oligocene period.* A species of Unio has been de- 

 scribed from the coal-beds in Otago. 



In the neighbourhood of Oamaru basic volcanic rocks 

 underlie the marine beds, and in other places of Otago and 

 Canterbury volcanic rocks are interbedded with the sediment- 

 aries which belong to the earlier part of the Oamaru series. 

 The most remarkable of these is a hydrated tachylyte, which 

 is found in several places between Lookout Bluff, near Hamp- 

 den, and Castle Hill, in the valley of the Waimakariri, a 

 distance of a hundred and fifty miles. f The volcanic system 

 of Dunedin probably belongs to the close of this period, as 

 also do the volcanic rocks in the neighbourhood of Palmers- 

 ton South, and those on the northern side of the Hurunui 

 Plains at Culverden and Pahau, as well also as a large part 

 of the volcanic rocks of Banks Peninsula. The older rocks 

 in the Dunedin Peninsula are andesites, followed by olivine 



* Mr. G. F. Harris is also of opinion that they are younger than the 

 Eocene of London, Paris, &c. (see " Catalogue Australasian Tertiary Mol- 

 lusea in the British Museum," p. 15 ; 1897). In the Geological IMagazine 

 for 1891, vol. 7, paga 491, Dr. T. W. Gregory quotes me as having oiioe 

 been of opinion that the Echinoderms belonged to Dr. Hector's Cretaceo- 

 tertiary. This is a curious mistake, for my paper on the correlations of 

 the Curiosity-shop beds was written to show that there was no Crctaceo- 

 tertiary formation in New Zealand. 



t Journ. Koy. Soc. of N.S.W., vol. xxiii., p. 152. 



