586 Transactions.— Geology. 
and in like manner the occurrence of the black oyster of the Waipara in the 
trigonia beds at Amuri Bluff affords us the means of comparing the very 
lowest beds in the two localities. Both the Amuri group and the saurian 
beds are much more indurated as they are followed north, and at Flax- 
bourne their lithological characters are very different to what they are 
either at Amuri Bluff or the Waipara ; heavy beds of volcanic rocks, with 
beds of indurated green sandstone, playing a prominent part in the compo- 
sition of the beds which underly the Amuri limestone. 
Having reviewed the opinions entertained by former workers in this 
field, and in part given a description of the beds in localities where they 
have come under my own observation, I now venture to place before you 
the views held by myself as to the age and conditions under which they 
have been deposited, and the after movements to which the beds have been 
subjected. 
As regards the question of their age, my labours in the field as collector 
to the Geological Survey Department have accumulated abundant evidence 
in the shape of fossil remains to prove the synchronism of the beds through- 
out, and also to indieate by means of highly characteristic forms, that all the 
rocks here specially treated of are of young secondary age; and if, as has 
been contended, some of the fossils obtained from the higher beds are also 
to be had in decidedly tertiary rocks, these beds thus objected to on account 
of their perfect conformity to the underlying and decidedly cretaceous rocks, 
cannot be considered as other than passage beds beiween it and the very 
lowest tertiaries ; and hence the classification of whole series of beds under 
ihe term ** eretaceo-tertiary," as proposed by Dr. Hector, even in the objec- 
tions of dissenters, receives its fullest verification. * 
The middle and lower beds of the series have generally been considered 
as of secondary age. Although Dr. Haast is not alone in assigning a ter- 
tiary age to these beds, in certain localities where the more characteristic 
secondary fossils are less abundant than at Amuri Bluff; as Captain 
Hutton considers the Saddle Hill and Green Island coal beds near Dun- 
edin to be of tertiary age, although many of the fossils from these beds 
are to be found associated with saurian remains at the Waipara and other 
localities, one or two cretaceous Cephalopods being common both to the 
Amuri Bluff and Otago deposits. As to the synchronism of the Waipara 
and Amuri Bluff beds, which Dr. Haast considers to be of different ages, at 
Amuri Bluff I obtained besides saurians of the same species many fossils 
common both to the Waipara and Malvern Hills; and at Flaxbourne and 
near Cape Campbell in beds that co-relate with the belemnite and trigonia 
* Although I here make use of the term ** passage beds " it is used in a paleontological 
sense only, a break occurring between these and our oldest tertiary rocks, 
