that Woods's specimen differs from true sacya and is very close to subsacya Marshall from a higher horizon. Considering all these points, and the faunas of the overlying Piripauan, we now suggest that the four divisions of the Clarentian outlined may be tentatively regarded as covering the period Albian to Coniacian. It is of interest that Belemnites superstes Woods is known only from the lower part of the Clarentian, and this species has been placed by Whitehouse (1924, p. 412) in Dimitobelus, known in Australia only from the Upper Albian.

Piripauan.

The Piripauan at its type locality (“beds at Amuri Bluff below the Teredo limestone”—Thomson, 1917, p. 409) consists of the following units:—basal sandstone with calcareous bands containing Mollusca, “sulphur sands,” black grit with shark teeth, and concretionary glauconitic sandstone (“saurian beds”). A detailed account has been given (Thomson, 1920, p. 341) of a similar succession in the not far distant Middle Waipara area, where basal coal-measures and Ostrea beds are followed by “saurian beds” and then by Waipara greensand; the occurrence of Cimoliosaurus australis (Owen) in the two latter, and of Pacitrigonia Marw. and Conchothyra Hutt. in the former, confirms the association with the type Piripauan. This is mentioned, since good micro-faunas have been obtained from the Mid-Waipara, but not as yet from Amuri Bluff. The Piripauan cannot be divided into several Cretaceous stages as conveniently as the Clarentian. It is only about 1000 feet thick and possibly covers a much shorter period of time. Most of its important Mollusca come from the basal beds, while Foraminifera are known only from the top of the “saurian beds” and basal Waipara greensands. Although the Clarentian and Piripauan are nowhere known to be in contact, the presence of different Inocerami in each, and the absence of any faunal agreement between the topmost Clarentian and any part of the Piripauan indicates that the two systems do not overlap. The characteristic Belemnite of the basal Piripauan, B. lindsayi Hector, has been made by Whitehouse (1924, p. 414) the monotype of Cheirobelus, as distinct from the Clarentian Dimitobelus; in the absence of related forms he accepted for it Woods's determination of a Senonian age.

The characteristic Inocerami of the Piripauan are australis and pacificus, both of Woods, but Heinz's work (1928) on these is somewhat contradictory. They occur together in the basal conglomerate, and black grit, and are certainly younger than the Clarentian forms, yet Heinz divided them into four different species, characterising four horizons from Cenomanian to Lower Emmscherian. Two other molluscan genera are of importance. Pacitrigonia Marwick (1932, p. 505) is a group apparently confined to the Upper Senonian of the Southern Hemisphere, while Conchothyra Hutton (see Finlay and Marwick, 1937, p. 64) has no outside close relatives, is limited in its type species to the Piripauan, but extends as another species to the Danian Wangaloan.

The North Island Tapuwaeroa Formation, from its rich micro-faunas may certainly be correlated with some part, if not all, of the Piripauan. It is therefore significant that at Mataikona, north of Castle Point, Tapuwaeroa beds with their index mollusc, Ostrea lapillicola Marwick (1926B), overlie a mudstone (probably the Mangaotane) carrying Inoceramus bicorrugatus Marwick, the index mollusc of the Clarentian Nidd mudstones; to the south-west of this, at Bush Grove Stream, beds similarly mapped as Tapuwaeroa contain the ammonite Parapuzosia aff. haughtoni Spath (1935, p. 11); this and other ammonites from the overlying Waipawa Series (Thomson, 1926B, p. 349) were referred by him to Senonian and Upper Senonian, but Whitehouse (1926, p. 279) has quoted Parapuzosia as indicative of a Lower Santonian age for the West Australian Gingin Chalk. The argillitic Whangai (= Waipawa) Series (see later) overlying the Tapuwaeroa is still intimately connected with it in micro-fauna, but not at all with the Eocene Bortonian (Wanstead and Upper Mangatu of North Island), so that it seems reasonable to refer both of these to the Piripauan, with a possible combined age of Santonian-Campanian.

“Teredo Limestone.”

It seems, however, that there are still higher horizons in the Cretaceous than any in the Piripauan System, the upper limit of which was inadvertently left open to confusion by Thomson. He defined it as including all beds below the “Teredo limestone,” but there are two Teredo limestones described (as Upper and Lower) by McKay (1877, p. 181) from the type locality. The upper of these is more persistent and constant in character, the lower being sometimes absent or overlooked when its facies changes to calcareous sandstone. Since McKay conceived these and the intervening greensands as a unit distinct from the underlying formation, the upper limit of the Piripauan is here fixed as the concretionary greensands below the Lower Teredo Limestone (see McKay's table, op. cit., p. 178). This definition is necessary since Belemnites have been collected by the Geological Survey not far south of Amuri Bluff, from the greensands four feet below the Upper Teredo Limestone. These are small and quite distinct from the Piripauan Cheirobelus, and presumably indicate a still higher stage, perhaps the Maestrichtian. At Shag Point Professor Park collected a few Beleminites from near the base of the Katiki Series (see Brown, 1938, p. 11); these are also small, but distinct from those at Amuri; the accompanying micro-fauna contains Dorothia elongata Finlay, characteristic of the Piripauan. Between this horizon and the Eocene Hampden section are the Katiki-Moeraki beds, whose micro-faunas have a pre-Tertiary aspect and little affinity with the overlying Bortonian, yet lack the characteristic Cretaceous species of the Piripauan—a description which has already been applied by Finlay and Marwick (1937, p. 7) to the Molluscan fauna of the Wangaloan. These beds may be approximately coeval, therefore, with either the Lower Teredo Limestone or the Wangaloan, neither of which has yet yielded a micro-fauna.

Approximate correlatives of these high Cretaceous horizons occur in the North Island, and have generally been referred to the Mangatu Series of Henderson and Ongley (1920, p. 34) and the Otamatea Series of Ferrar (1934, p. 25). The former name has been widely employed for formations ranging from Lower Piripauan to Upper Oligocene, and is too wide in application. It is at present being re-investigated and the type locality systematically collected for micro-faunas. Restriction and use of the name should await results from these. Because of this uncertainty, the term Whangai was proposed by Quennell (1937, p. 3) for the argillitic series of Hawke's Bay. It is equivalent in part at least to the Mangatu and perhaps partly to the Tapuwaeroa, but is also being re-investigated at present. Chocolate shales occurring above the Whangai have a micro-fauna comparable with that of the Moeraki beds, and are similarly overlain by a formation (Wanstead whitish mudstones) with Bortonian faunas, both Lower and Upper.

Kaitangatan and Wangaloan.

One other System-Name, the Kaitangatan, needs mention. Thomson proposed it to include the Kaitangata upper and lower coal-measures as described by Park (1911) and the intermediate marine horizon, but excluded the Oamaruian coal series and overlying Oamaruian marine rocks. He did not know this section at first hand, and accepted Park's sequence; Ongley (1926, p. 7, and 1939), however, has shown that the “intermediate” marine horizon really overlies both coal-measures (see also the columnar sections comparing Kaitangata, Brighton, and Boulder Hill in Finlay and Marwick, 1937, Pl. 18). The coal-measures with quartz conglomerate may be the same age in the various localities, but whether this is so or not, at Brighton the overlying marine horizon contains Belemnites, while at the other two places the Danian Wangaloa beds (without Belemnites) overlie the coal measures. The Belemnites belong to the Dimitobelidae and are very poorly preserved; they were thought by Whitehouse to be possibly Albian (which would mean a Clarentian age), but the subsequent finding of Pacitrigonia Marw. and Venericardia Lamk. in the Brighton Limestone (Ongley, 1939, p. 55) makes correlation almost certain with the Piripauan. Two very different horizons are concerned, the Wangaloan being much younger and either equivalent to the mudstones above the Belemnite bed containing Lahilleona Marw., or even higher. It is, however, obvious that most of the Kaitangatan System below the actual Wangaloan is Piripauan or older and, since the Kaitangatan can hardly be thus restricted to one stage, it has to be dropped entirely from the column of marine stages. The Dimitobelid Belemnites in the Brighton Limestone place it below the Teredo Limestone, while the Wangaloan itself, from the absence of Belemnites, etc., must be younger; the evidence for a suggested Danian age has been presented by us previously (1937). Chapman (1934, p. 119) has reported the Upper Cretaceous fish genus Portheus from the glauconitic mudstone overlying the Brighton Limestone at Abbotsford. From shaft spoil in the neighbourhood, McKay collected Lahilleona, Trigonia cf. waiparaensis Woods, and Dentalium morganianum Wilck.; these were considered