Aptychi seem to be extremely rare in the Japanese Jurassic, Cornaptychus nagatoensis NAGAO from the Lias of the province of Nagato being the unique example hitherto recorded. Recently Prof. H. YABE of the Institute of Geology and Palaeontology, Tohoku Imperial University, kindly submitted for determination to the. writer an aptychus obtained from the Upper Jurassic rocks in the southern part of the Kitakami Mountainland ill Northern Honsyii. The specimen is, as described below, represented by a cast of a two-valved operculum with the ornamentation of either outer or inner surface impressed on the matrix. The parent ammonite is unknown at present. In the district where this operculum has been obtained, the Upper Jurassic rocks composed mainly of dark coloured hard slaty shale alternated with sandstone are developed. On the label sent to the writer together with the specimen is recorded that it had been found at a locality with, separately, a specimen of Perisphinctes (Aulacosphinctes?) sp. No ammonite of other genera is yet reported to occur in this complex, it will be very natural to suppose that this operculum belongs to some form of this genus.

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The, present specimen was collected by the writer from the southern slope of Doniwayama, Nenosiroisi-mura, Miyagi-gun. Although represented by only a single cast, it appcars io he new lo science and is given the following name and description.

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During a short trip to several localities within Aomori Prefecture, the writers had a chance to visit the Hukaura beds, and to collect some fossils from the beds. Hitherto, the Hukaura beds have been known to be very young in aspect, but as to the geological age from fossil-content, nothing was known. This is due to the fact, that the Hukaura beds are very scanty in fossil content, and that to collect even a few fragments, considerable time is required. The fragments collected by the writers are briefly mentioned in this article in order that other authors in concern may get an idea of the kind of fossils the Hukaura beds contain.
The Hukaura beds, as worked out by S. SHIBAYAMA in his graduation thesis, is the youngest Neogene deposit found in Nisi-Tugaru District, and consists of soft pumiceous tuff, cross-bedded loose sandstone, coarse-grained sandstone, sandy conglomerate and rather calcareous sandstone, with some shale. The present fossils of the writers are from the calcareous sandstone and coarse-grained sandstone layers. The Hukaura beds unconformably overlie the next older Azigasawa beds, which in turn is conformable to the underlying Akaisi beds; the Akaisi beds are unconformable to the next older Tanosawa beds, which in turn unconformably overlie the lowest or Odose beds.

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The Amaze Oil Field is situated in Izumozaki-mati, Niigata-ken and eight samples collected therefrom-constitute the material of this research. More precisely, three of them were collected from the Haizume Formation, one from the Nisivama Formation, three from the Siiva Formadon, and one from the Teradomari Formation, Fig. 1 shows these fossil localities. The significallt Foraminiferas of the faunas contained are listed in Table 2.
Haizume Formation: Loc. 55 and Loc. 57 are situated nearly in the same horizon. Loc. 58 is somewhat upper in horizon than the former two localities. The leading members of the Foraminiferan fauna from Loc. 55 and Loc. 57 are Textularia sagittula, Quinqueloculina vulgaris, Cassidulina japonica, Globigerina bulloides and Cbicides lobatulus. Cibicides refulgens is predominant in Loc. 58, but Cassidulina japonica is not found in it. The Foraminiferan fauna from Loc. 55 and Loc. 57 reveals a close affinity with that of Kutta which YABE and HANZAWA reported in 1923, Here I suggest the Kutta assemblage to designate this fauna in the Amaze and the Nisiyama Oil Fields.
Nisiyama Formation: Only one sample was collected, and the Foraminiferan fauna is very small in the number of species and individuals.
Siiya Formation: Three samples were at hand. Haplophragmoides subgrobosum and Goesella sp. 1 are dominant in the one from Loc. 66 and a few species of Nonionides, Buliminidae and Rotaliidae are contained in the two others, but the predominant species in the Haizume Formation can not be found in this.
Teradomari Formation: Cyclamina pauciloculata is common.
In order to show the relative abundance of different families in the three localities, Loc. 58, Loc. 55 and Loc. 57, in the Haizume Formation, a value is arbitrarily assigned to each letter in the cheek list: R=1, C=10, A=20. Table 3 shows the number of abundance for each family based on these approximate figures and the percentage of abundance for each family in the three localities when the total number of abundance in Loc. 57 was taken as 100. Fig. 2 A is a graphic interpretation of this table. Fig. 2B shows the relationship of the families in twelve localities in the Higasiyama and Araya Formations of the Higasiyama Oil Field.

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As fossil elephants have not been known from the prefecture except Stegodon orienatalis shodoensis described by H. MATSUMOTO, the present occurrences are of special interest. The one discovered in the Wanazu sandstone formation at Okada, Takayanagi-mura, Kariha-gun is Parastegodon cf. akashiensis and the other found in the Oguni brown coal bearing formation at Sizyuppo, Tatibana-mura, Naka-Uonuma-gun, is Palaeoloxodon namadicus naumanni.
In regard to the horizons whieh yielded the fosgils, the former is indicative of the early Pleistocene age and the latter of the late Pleistocene.Since Pleistocene deposits are not very well represented in the region and opinion has generally been that the Wanazu sandstone formation is late Pliocene, the find of Pleistocene mammalian remains provides important keys for future research. Finally it may be noted that MATSUMOTO's specimen may possibly be misidentified for it appears to me to be identical with Parastegodon cf.akashiensis.

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