94 Transactions. 



C. Globigerina Ooze. 



The first six limestones described here are generally called hydraulic 

 limestones. The others are generally classed as Amiiri limestone. 



(«.) Kaiwaka, Kaipam Harbour. Plate X, fig. 2. 



The only distinct organism is Globigerina, which is present in great abun- 

 dance. The chambers are generally filled with secondary calcite, though 

 here and there with glauconite. Several sponge-spicules of perfectly iso- 

 tropic silica. A few radiolarians. Some brown hydrous mica and a very 

 few extremely minute quartz grains. This limestone is associated with a 

 stratum of diatomaceous and radiolarian ooze. 



(6.) Por! Albert, Kaipara Harbour. 



Globigerina very abundant, and a small Dentalina ? Chambers generally 

 filled with calcite, but occasionally with pyrite. One radiolarian and many 

 calcified sponge-spicules. A small amount of glauconite and brown mica. • 



(c.) Port Albert WharJ. 



Much glauconite and a few minute grains of quartz. No Foraminifera 

 except Globigerina can be seen. There is a great deal of finely granular 

 calcite and some of the brown mica. 



((/.) Wellsjord, North Auckland. 



Slice much broken by small veins of crystalline calcite. Globigerina is 

 the only organism, but the greater part of the rock is formed of finely granular 

 calcite. There is a little glauconite and some of the brown mica. 



o* 



(e.) Limestone Island, Whangarei Harbour. 



A true Globigerina ooze, with crystallized calcite occupying the interior 

 of the chambers. Very few minute quartz grains, and some glauconite and 

 some pyrite. 



(/.) Mahurangi, North Auckland. 



Many small veins of secondary calcite. Globigerina the only recognizable 

 organism. The larger chambers are crushed. A little glauconite, but no 

 detrital grains. 



(^f.) Kaikoura. 



A pure Globigerina ooze, with a very occasional grain of glauconite. 

 Some sponge-spicules and several examples of a radiolarian. A little 

 brown mica. 



{h.) Otaio, Canterbury. 



A fine-grained type, with many minute quartz grains and a good deal of 

 glauconite. Mainly Globigerina, but one specimen of Amphistegina. 



(i.) Amuri, Blujj, Marlborough. 



The organic remains are nearly entirely Globigerina, the chambers of 

 which are separated. A few grains o glauconite and sponge-spicules. 

 Radiolaria are not infrequent. There is a little of the brown mica. 



