Micro-Faunas. Since Allan's paper appeared much light has been thrown on correlation problems by intensive study of the Foraminifera. The well-known advantage of this group is that excellent faunas can frequently be obtained from important localities poor in or lacking macro-fossils. The result is that where, before, we had relatively few abundant mollusc or branchiopod faunas, unequally distributed, we now have hundreds of rich rhizopod faunas covering almost the whole Tertiary, and can observe and separate faunal changes due to the time factor in a way previously impossible. Although the stratigraphic implications of the Foraminifera have received special attention for several years, the systematic descriptions are only now being published. In the first of these papers to appear, a revised classification of New Zealand stages has been put forward, based on both macro and micro-faunas (Finlay, 1939A, p. 531). This is the table adopted here, with the exception that the Upper Cretaceous is added, and the two divisions of the Taranakian have been reinstated for reasons given later. Table of New Zealand Stages. Upper Castlecliffian (Thomson) Pliocene Middle Nukumaruan (Morgan) Lower Waitotaran (Thomson) Opoitian (Finlay) Urenuian (Henderson) (Taranakian) Upper Tongaporutuan (Marwick) Miocene Middle Awamoan (Thomson) Lower Hutchinsonian (Thomson) Waitakian (Park) Upper [includes Duntroonian (Allan)] Oligocene Middle Whaingaroan (Finlay) Lower Kaiatan (Morgan) (Ototaran) [includes Waiarekan (Thomson)] Eooene Upper Tahuian (Allan) Middle Bortonian (Park) (Waimatean) Lower (present but not named) Danian Wangaloan (Morgan) Maestrichtian ? Campanian “Mangatu” (Piripauan) Santonian “Tapuwaeroa” Cretaceous Coniacian Turonian (Clarentian) Cenomanian “Raukumara” Albian Aptian “Taitai”