Thomson. — Stage Names applicable to Divisions of Tertiary. 39 



{Dacrydium capressinum and Ulmophylluni latijolium) whieli are known from 

 the Pakawau horizon. 



Although relatively very little is known of the fossil floras of undoubtedly 

 Oamaruian horizons, the absence of any common species in the few species 

 known and in the relatively well-known Pakawau-Brunner flora suggests 

 that the latter is older than the Oamaruian ; but until either the flora has 

 been shown to be distinct from the Ngaparan flora or the fauna of the Kaiata 

 mudstone and Island sandstone has been shown to be distinct from the 

 Waiarekan fauna it would be unsafe to base a stage name on the Brunner 

 series. It is certain, however, that even if the latter is Ngaparan the 

 Paparoa series is older, and a stage may be safely based on it, and may 

 be termed the Paparoan. 



V. Summary and Conclusions. 



Care has been taken in the above discussion to admit no stages that 

 are likely to overlap on others. The following table gives the complete 

 sequence of those proposed, and indicates the. possible gaps : — 



Marine Stages. Coal-beds. 



„r ■ { Castlecliffian. 



Wangamuan .. j Waitotaran. 



(Other stages possible.) 

 Awanioan. 

 Oamaruian . . Hutchinsonian. 



Ototaran. 

 Waiarekan. 



(Other stages possible.) 



Ngaparan. 

 Paparoan. 



Other stages for coal-beds are clearly necessary. Thus at Maharahara 

 the coal-measures are immediately folloAved by marine beds with a Wanga- 

 nuian and probably a Waitotaran fauna. The naming of these is best 

 postponed until the correlation of the overlying marine beds with the 

 named marine stages is rendered more definite. 



The determination of the molluscan and brachiopodan fauna of the above 

 marine stages has occupied the attention of Mr. Suter and myself for some 

 considerable time, and it is hoped to publish the results before long.. Fiesh 

 collections from any of the localities chosen as the types for stages will be 

 gladly welcomed, for, although large collections have been examined, it is 

 certain that much further collecting is still necessary before the complete 

 range of the species can be stated, and until that is known correlations 

 based on purely palaeontological grounds cannot have much value. The 

 determinations so far made show that there a number of species which 

 have a wide range in horizon and are also widespread in occurrence and 

 abundant in the beds in which they occur. Such fossils are of little use as 

 indications of horizon when taken singly. Fossils that are rare, and known 

 from few localities, are obviously also of little use, for their rarity prevents 

 their range being adequately known, while their absence in any given 

 locality cannot be taken as evidence that they did not exist elsewhere at 

 the time the beds of the said locality were being deposited. What must 

 be sought are fossils which are at least moderately abundant and yet 

 restricted in range. If such species can be found— and the experience of 

 other countries suggests that they can — correlation will be enormously 



