4 W. N. BENSON 



platform beneath the younger formations. Their occurrence 

 also supports the hypothesis that the dioritic rocks are not younger 

 than early Mesozoic. 



Silurian. — The fossiliferous Silurian strata are known in two 

 localities only, both in the northwest of the South Island. They 

 strike in a direction usually about north-northwest, the same as 

 that of the Ordovician rocks, but their relation thereto is as yet 

 unknown, nor are the conditions at all favorable for investigating 

 this. In the northern of the two areas (Baton River) the rocks are 

 calcareous argilHtes, but in the southern occurrence (Reefton) 

 they are of more littoral and varied nature, with a consequent 

 difference in faunal facies. Both faunas are apparently closely 

 related to the Upper Silurian (Wenlock) faunas of Southeastern 

 Australia, but have not yet been very critically examined. 



" Permo-Carboniferous'' and Lower Mesozoic. — No further infor- 

 mation is available until the close of the Paleozoic era, when com- 

 menced the more nearly continuous portion of the stratigraphical 

 record. The greater part of the mountainous country of New 

 Zealand is made up of steeply folded and shattered argillites and 

 graywackes, generally devoid of fossils. They contain, though 

 rarely, lenticular masses of limestone, and also, especially in the 

 upper portions intercalated plant beds. Widespread basic tuffs, 

 etc., occur in the lower portion. On one higher horizon basalt flows 

 are present. Numerous subdivisions and groupings have been 

 proposed for this series, and Trechmann's recent paleontological 

 work, supported by that of Arber, Wilckens, and Boehm, seems 

 to place on a firmer basis than formerly the division of the complex 

 into a series of formations ranging from Permian to early Creta- 

 ceous age. 



Permian. — The oldest fossiliferous rocks seem to rest conforma- 

 bly on an extensive series of basic breccias, which are probably coeval 

 with similar breccias which elsewhere rest unconf ormably on Silurian 

 rocks. The fossihferous beds, limestones, and argillites contain 

 at one locality (near Nelson) a few poorly preserved shells and 

 corals which have been compared with Eastern Australian Permo- 

 Carboniferous (Permian) forms. Among these is a large, indefinite 

 myalinid shell which was referred doubtfully to Inoceramus and 



