402 Transactions. — Geology. 



probably T. pseudo-simpl&x and T. lomariopsis, Ettings. ; and a 

 species of Taxitesr' 



The conformable relation of the Mataura Falls beds to the 

 Trias is clearly seen in the section from Mataura to Gore. 



The conformable relations of the Mataura series (syu., 

 Matai series) of Sandy Bay and Catlin's beds to the Trias of 

 Nugget Point have already been described. 



Age of Mataura Series. 



Baron Von Ettingshausen, who examined a collection of 

 plants from the Mataura Falls beds, stated that "the species 

 bear more or less the facies of those of the Triassic flora,"! a 

 •conclusion quite in harmony with the stratigraphical evidence, 

 which shows that the plant beds follow the Upper Trias. The 

 boundary between the two formations is quite arbitrary, and 

 might easily be fixed so as to place the plant beds in the Trias. 



On the other hand, the presence of Inoceramus, Beleinnites, 

 and Ammonites in the Mataura beds, and Inoceramus in the 

 Maitai and Dun Mountain beds, clearly establishes a relation- 

 ship to the Jurassic rather than to the Triassic period. 



No attempt has been made to subdivide the Jurassic and 

 Trias rocks into minute groups of beds. This is a work 

 that can only be successfully accomplished when the fossils 

 have been determined by a palaeontologist. Minute subdivi- 

 sion vv'hich is not supported by accurate detail and clear 

 definition is certain to be abandoned, and this has been the 

 history of many attempts at subdivision in New Zealand 

 where the facts were not sufliciently ascertained or supported 

 by accurate data. 



To avoid confusion in the literature of the subject I have 

 ■discarded many of the old names, some of which were used 

 by different authors with different meanings. The local 

 names adopted by me refer to places where the rocks thus 

 ■designated are typically developed, and where their relation- 

 ship to the associated formations is clearly defined. 



Distribution of Mataura Series. 

 In my paper on the Jurassic age of the Maitai series I 

 showed that the rocks of that series, as typically developed 

 in Nelson, overlaid the Trias conformably, and contained tlie 

 Secondary genus Inoceramus in abundance. On these grounds 

 I contended that the Maitai rocks could not be Carboniferous, 

 but must be subsequent to the Trias ; and I therefore referred 

 tliem back to the Jurassic period, where they were originally 

 placed by Captain Hutton in 1875. The evidence seems 

 conclusive tliat the Maitai and Mataura rocks are contem- 



• Eeps. Gcol. Expl., 1886-87, p. 146. 

 t Trans. N.Z. Inst., vol. xxiii., p. 42. 



