350 Transactions. 



It will be seen that the hard white limestone at the top consists of 

 80 to 88 per cent, of carbonate of lime and 14 to 6 per cent, of silica. The 

 grey limestone 50 ft. to 80 ft. below the upper surface contains only 66 per 

 cent, of carbonate of lime. 



The Amuri limestone contains few microscopic fossils either within 

 the district or elsewhere. In the small gorge above the viaduct in the 

 Weka Pass I observed a small fragment of a Pecten about 25 ft. below the 

 upper surface. Foraminifera constitute a fair proportion of the rock, and 

 from a collection which I made from the uppermost 3 ft. in the above 

 locality Mr. F. Chapman determined the following forms : Guembelina 

 globulosa (Ehr.), Bulimina obtusa d'Orb., Bulimina sp. nov., Globigerina 

 cretacea d'Orb., Anomalina ammonoides (Eeuss), and Pulvinulina elegans 

 (d'Orb.). From the same locality, 25 ft. to 30ft. below the upper surface, 

 he determined Nodosaria annulata Reuss, Globigerina bulloides d'Orb., ^ 

 Anomalina ammonoides (Reuss), and Pulvinulina elegans (d'Orb.). These 

 forms, he considers, establish the Danian age of the rock. 



The underlying glauconitic mudstones yield Foraminifera, Ostracoda, 

 fish -scales and vertebrae, and fragments of molluscs and brachiopods. 

 The fossiliferous nature of this horizon has only recently been established, 

 and the specimens, excepting the brachiopods, have not been examined 

 by specialists. The brachiopods include a species of Aetheia hardly dis- 

 tinguishable from the Oamaruian A. gaidteri. The remainder bear no 

 resemblance to Oamaruian species, and include a new genus of Terebratellid. 

 I hope to describe these and other Cretaceous brachiopods in the near future. 



Waipara River. — The best section through the Amuri limestone is that 

 afforded by the banks of the Waipara River at the Limestone Gorge and 

 on the south bank for some distance above it. The following beds are 

 exposed : — - 



Hard, white (chalky), closely-jointed limestone, including Feet. 

 a few marly bands near the base . . . . 100- 



Softer, grey, argillaceous (marly) limestone with 'Coarser 



bedding and jointing . . . . . . . . 60 



Grey mudstone, passing down into dark blue-grey streaky 

 mudstone, with nests and streaks of glauconite . . 300 



The upper white hmestone is thin-bedded and closely jointed in all directions. 

 It forms nearly vertical cliffs, passing below into grassy talus-slopes. The 

 grev limestone is thicker-bedded and less jointed, and has a spheroidal 

 weathering like a mudstone. It is sometimes known as the " fucoidal 

 limestone,"" from the presence of a peculiar fossil (?) known as the Amuri 

 '' fucoid,"" shown in fig. 5. This consists of rudely conical masses of limestone, 

 with the apex of the cone directed upwards, the diameter of the base ranging 

 from a few inches up to 3 ft. From the apex of the cone coarse flutings 

 radiate to the exterior, the flutings being rounded on the bottom, and the 

 intervening ridges rounded or angular according to the shape of the flutings. 

 The surfaces on which the latter are developed are not strictly conical, 

 but sometimes almost spiral, as in the figure. Occasionally the flutings 

 bifucate. The " fucoids "' occur chiefly in the main mass of the grey marly 

 limestone, but are best displayed in a marly band, about 18 in. thick, 10 ft. 

 above the base of the white limestone. Besides the " fucoids " the grey 

 limestone contains numerous Foraminifera and many small chitinous flakes. 

 It was to a small fragment of the Amuri " fucoid," labelled " Culverden," 

 but more probably from the Waipara or Amuri Bluff, that Hutton gave 

 the name of Pinna jolicata. 



