Hutton. — The Wanganui System. 889 



of blue clay (PI. XII., fig. 1, a), about 40 feet thick, and full 

 of fossils. A layer of yellow sand (b) rests upon this clay, 

 apparently quite conformably; it is about 20 feet thick, and 

 contains broken shells. Then conies a thin bed of sand, 

 about 4 feet thick, with abundance of fossils. Then another 

 bed of sand, about the same thickness, followed by a bed ol 

 gravel (c) cemented by iron oxide. This is followed by a bed 

 of dark green sand [b). All these belong to the Wanganui 

 system ; they have suffered much denudation, and are overlain 

 quite unconformably by a series of silts and gravels (d) which 

 are unfossiliferous. 



At Landguard Bluff, or Putiki, near the mouth of the river 

 on the left bank, the blue clay is not seen, but the upper beds 

 are largely developed. The lowest stratum is yellow sand with 

 broken shells, followed by sand with shells (Fig. 2, b), sands and 

 clay, cemented gravel (c), and greensand, as at Shakespeare Cliff. 

 But above the greensand is another bed of sand with shells (b) 

 and white clay. At the point forming the Bluff, there is a fault 

 of about 30 feet (x), caused apparently by a laud slip. Round 

 the point some small beds of lignite lie on the cemented gravel. 

 The upper beds are denuded, and overlain unconformably by 

 unfossiliferous silt and gravels, as at Shakespeare Cliff. 



The Wanganui system in this district may therefore be 

 represented as follows, the known thickness being between 150 

 and 200 feet :— 



Putiki Series, near Wanganui. 



9. White clay, about 4 feet. 



8. Sand, about 12 feet. 



7. Sand with fossils, about 5 feet. 



6. Greensand, current bedded, about 25 feet. 



5. Cemented gravel, from 10 to 20 feet. 



4. Sand with clay, from 4 to 50 feet. 



3. Sand with fossils, from 4 to 10 feet. 



2. Sand with broken shells, from 12 to 20 feet. 



1. Blue clay with fossils, 40 + feet. Bottom not known. 



No pumice has been found in any of these beds. The blue 

 clay is quite conformable to the upper beds, and contains the 

 same fossils. I know 133 species of mollusca from the blue 

 clay, all but 21 of which also occur either in the upper beds or 

 in the Petane series. But of these 21, thirteen are still living in 

 the New Zealand seas, and must therefore have been living when 

 the upper beds were being deposited, although their remains 

 have not yet been found in them. This leaves eight species out 

 of 133, as distinctive of the blue clay, and of these only one — 

 Vermetus moniliferus — is found in the Pareora system. This 

 small difference between the fossils of the blue clay and those of 

 the upper beds is easily accounted for by difference of station ; 



