Park. — Marine Tertiaries of Otago and Canterbury. 513 



Of the above twenty-eight species, eight, or 28-5 per cent., 

 are living ; and of the twenty extinct forms nine were found 

 by me in the Hampden beds. Eight species have never, so 

 far as I can gather, been found in beds overlying the Waitaki 

 Stone. They are Ancilla hebera, Girsotrema broivni, Scaphella 

 corrugata, Dentalium mantelli, Limopsis insolita, Pseudamus- 

 sium hiittoni, Pecten williamsoni, Mactropsis traili. To these 

 should probably be added Natica darioini and Pleurotoma fusi- 

 formis. 



Cape Oamaeu. 



Proceeding southward from Oamaru Breakwater the sea- 

 cliffs are found to consist of lavas and agglomerates. About 

 15 chains past the first point, at a shallow indentation where a 

 blind gully descends to the sea, the agglomerates are under- 

 lain by a series of bedded ash-beds, greensands, silts, and 

 sandstones, the two former containing bauds or beds of 

 impure limestone. The ash-beds and sandstones dip towards 

 the north at an angle of about 25°, and rest upon a flow 

 of basalt which occurs in pillow-form masses aloug the base of 

 the cliff. The interstices between the masses are filled with 

 calcareous sandstone or impure limestone. 



The pillow- form structure of a lava is not often seen, and 

 this is, I believe, the first record of it in New Zealand. An 

 occurrence of this structure, almost identical with that at 

 Cape Oamaru, is exposed on the beach near Ballantrae, in 

 south-west Scotland. It has been described by B. N. Peach 

 and J. Home, and figured by them in the Memoirs of the 

 Geological Survey of the United Kingdom for 1899. * In this 

 case the interstices between the pillow-form masses are filled 

 with Silurian limestone. 



Stratigraphy. 



Here we have unmistakable evidence of contemporary 

 volcanic activity. The lava was poured over the floor of 

 the sea, and in cooling assumed a remarkable pillow-form 

 structure resembling a number of large pillows piled one 

 upon the other. The presence of impure limestone and sandy 

 matter filling the spaces between the pillow-form masses, 

 and the rapidly alternating character of the tuffs and fos- 

 siliferous beds immediately overlying, present conclusive 

 evidence of the submarine character of the eruptions. The 

 lithological features of the rocks and the fossil contents 

 serve to correlate these beds with the Hutchinson Quarry and 

 Kakanui limestone horizon. 



* " The Silurian Eocks of Scotland," vol. i. ; London, 1903. 

 33— Trans. 



