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Transactions. 



on rocks with Tertiary fossils. It is not known south of the Trelissick 

 Basin. 



A further argument advanced by Marshall in support of his correlation 

 is the statement that Thomson and Speight have discovered a (Miocene) 

 molluscan fauna in the beds beneath the Amuri limestone in the Trelissick 

 Basin. In this cate Professor Marshall seems to have misunderstood a 

 verbal statement. There is a molluscan fauna beneath the Amuri lime- 

 stone of the Trelissick Basin, the genera represented being Ostrea and 

 Inoceramus. The fauna intended to be indicated by Marshall is of an 

 Oamaruian type, and lies near the top of the Amuri limestone. There 

 is no reason, however, to regard it as Ototaran rather than Waiarekan. 



The substantial palaeontological arguments advanced by Marshall thus 

 have no reference to the typical Amuri limestone of Marlborough and North 

 Canterbury, and apply to rocks of other districts which are correlated on 

 lithological grounds alone with the Amuri limestone. The evidence advanced 

 by myself (1916, No. 2) is drawn from the district within which the typical 

 Amuri limestone occurs, and is the only evidence at present available on 

 which an opinion may be based. 



Marshall (1916, No. 2) has himself brought forward new evidence which 

 militates directly his position. From his description of the fossils of the 

 beds at Wangaloa it is clear that this fauna occupies a position inter- 

 mediate between the Senonian and the Oamaruian.* If the Amuri lime- 

 stone follows the Senonian conformably, as Marshall believes, and correlates 

 with the Ototaran, then between it and the Senonian beds there should be 

 developed beds which are the equivalent of the Waiarekan, the Ngaparan, 

 and the Wangaloa beds. The section observed by me in the Waipara River 

 between the limestone gorge and the Doctor's Gorge is as follows :- — 



Oamaruian Weka Pass stone. 

 j Hard white short-fractured limestone in- 

 cluding a few marly bands . . 

 , Grey marly limestone 

 Grey marly limestone passing gradually 

 down into a dark blue-grey mudstone 

 with plant remains, glauconitic at 

 the base 

 I A few well-marked hard bands of green- 

 sand with Saurian teeth 

 Black glauconitic mudstone with yellow 



efflorescence 

 Concretionary greensands 

 Purple mudstones (Saurian beds) with 



yellow efflorescence ... 



Sulphur sands passing down into white 



sands 

 Poecilitic sandstone ] 

 Ostrea bed ) 



Sandstones and fine conglomerates with 

 , coal 



Amuri limestone 



Senonian 



Feet. 



100 



60 



150 



6 



80 

 150 



100 



200 

 15 



40 



* This discovery is one of the highest importance, and greatly simplifies our problems 

 of classification. It fills the palaeontological gap caused by the unfossiliferous nature 

 of the Amuri limestone, and thus removes one of our greatest stumbling-blocks. Pro- 

 fessor Marshall is to be heartily congratulated on his discovery. 



