奈良教育大学学術リポジトリNEAR
Nannofossils from Japan III. Miocene
Coccolithophorids from Noto, Central Japan
著者 NlSHIDA Shiro
journal or
publication title
奈良教育大学紀要. 自然科学
volume 19
number 2
page range 119‑130
year 1970‑11‑30
URL http://hdl.handle.net/10105/3033
Bull Nara IJ Educ., Vol. 19, No.2, (Nat.), 1970
Nannofossils from Japan IE. Miocene Coccolithophorids from Noto, Central Japan
(With 3 plates)
Shiro NlSHIDA
(Department of Earth Science, Nara University of Education, Nara, Japan) (Received May 28, 1970)
Introduction
The author previously reported on the Miocene discoaster assemblage from Noto, Central Japan (NlSHIDA, 1969). Before then, he reported briefly and orally on the nannofossil assemblage from the same samples (NlSHIDA, 1968a & 1968b).
In the present paper the author described seventeen species of coccolithophorids occurred with the discoaster assemblage. Descriptions on the samples studied, their stratigraphic relationships and the method of study are the same as written in the previous reports. The occurrences of the coccolithophorids from the Suzu formation are as follows ', Seven species of coccolithophorids occurred respectively from the Akagami shale and Hojuji diatomaceous mudstone members. They are Calcitrema sp., Coccolithus aff. C. helis, C. pelagicus (WALLICH), Cyclococcolithus sp., Discolithina multipora (KAMPTNER), Ellipsoplacolithus cf. E. productus and Helicopontosphaera kamptneri. From the Iida diatomaceous mudstone member eleven species of coccolithophorids occurred. They are Coccolithites sp., Coccolithus consuetus, C. doronicoides, C. pelagicus (WALLICH), C. sp., Cyclococcolithus formosus, Discolithina cf. D. cristata (KAMPTNER), D. sp., Tiarolithus sp.,
Umbilicosphaera aff. U. cricota (GARTNER) and U. cf. U. mirabilis. From the Najimi mudstone member Coccolithus pelagicus (WALLICH) and Helicopontosphaera kamptneri occurred. In these coccolithophorid species Coccolithus pelagicus
(WALLICH) commonly occurs from the three members. Its considerable occurrence is significant in the assemblages. A discussion about the present coccolithophorid assemblages is not intended.
The writer wishes to express his sincere thanks to Professor Misaburo SHIMAKURA of Nara University of Education for his constant encouragement and valuable suggestion.
119
120 Shiro NlSHiDA
The present paper was read at the 104th regular meeting of the Palaeontological Society of Japan held at Tohoku University, Sendai in January 19, 1970.
Systematic description
PLANT KINGDOM
Division PHAEOPHYTA WETTSTEIN (1901)
emend. ROTHMALER, 1949
Class COCCOLITHOPHYCEAE ROTHMALER, 1951
Order HELIOLITHAE DEFLANDRE, 1952
Family COCCOLITHOPHORIDAE LOHMANN,1902
Genus Calcitrema KAMPTNER, 1963
Calcitrema sp.
PL I, Figs. 4-5
Description : Elliptical or nearly circular shield with a wide central opening.
Ring-like shield composed of thirty-six rectangular segments which imbricate sinis- trally. Inner circle of the shield serrate sharply. Fine structures in the central opening are broken off.
Diameter of the specimen is about 5.5/*. Diameter of the central opening ranges from 2.5a to 3.2/«.
Hypotype : PI. I, Figs. 4-5 (1-4;NC4R-68, 1-5."NC1R-51).
Remark : Precise position on the taxonomy of the specimen is not determi- nable at present.
Genus Coccolithites KAMPTNER, 1955 Coccolithites sp.
pi. n, Fig. io
Description : Placolith, elliptical in plane view with thick rim and a central pore. Fine structures of the specimen are obscure for the later external calcite deposition on the surface.
Diameter of the hypotype is approximately 3. 5/*.
Hypotype : PL fl , Fig. 10 (NC9R-168).
Genus Coccolithus SCHWARTZ, 1894
Coccolithus consuetus BRAMLETTE & SULLIVAN 1961 PL I,Fig.9
Coccolithus consuetus Beamlette & Sullivan 1961, p. 139, pi. 1, fig. 8 ; BouCHfi, 1962, p. 83, pi. 1, fig. 18 ; Sullivan, 1964, p. 180, pi.3, fig. 1 ; Levin & Jobrger, 1967, p. 164, pi. 1, fig. 1.
Nannofossils from Japan I. Miocene Coccolithophorids from Noto, Central Japan 121
Description : Placolith, elliptical in plane view with closely appressed shield, convex distally, concave proximally. Sutures on the distal shield radiate straightly.
Rectangular segments imbricate dextrally. X-shaped structure spans transeversely on the central opening.
Diameter of the hypotype is about 5.5/<. Diameter of the central opening is about 2.5A.
Hypotype : PI. I , Fig. 9 (NC9R-46).
Remark : Reported stratigraphic distribution of this species ranges from the Paleocene to the Lower Eocene.
Coccolithus doronicoides BLACK & BARNES 1961 PI. I, Figs. 4-6 & 10-ll, &PL E, Fig. 8
Coccolithus doronicoides Black & Barnes 1961, p. 142, pi. 25, fig. 3 ; McIntyre et al., 1967, pp.
8-9, figs. A-B; Cohen & Reinhardt, 1968, p. 293, pi. 20, fig. 4.
Description : Placolith, elliptical or almost circular in plane view with closely appressed and nearly equal sized shields. Shields convex distally and concave proximally. Segments of the both shields are equal in number, gently curved and bluntly pointed. Segments on the each shield are about fifty in number. Central opening of some specimen is large and fine structures are obscure (vid. PI. I , Figs. 10-ll). Another central opening of this species is small and has bowl-like bottom (vid. PI. I , Figs. 4-6). Well preserved specimen has a grill-like structure in the central pore (vid. PI. H, Fig. 8).
Diameter of the hypotype ranges from 4.0/< to 7.0A-
Hypotype: PI. I, Figs. 4-6 & 10-ll, & PI. E, Fig. 8. (I-4;NC9R-39,
I-5JNC9R-94, I-6;NC9R-98, I-10;NC9R-10, I-ll;NC9R-96, H-8;
NC9R-76).
Remark : Reported stratigaraphic distribution of this species ranges from the Tertiary to the Recent deep-sea ooze.
Coccolithus aff. C. helis STRADNER 1963 PL H,Fig.5
Coccolithus helis Steadnee 1963, p. 7, pi. 1, fig. 9 ; Beamlette & Maetini, 1964, pp. 298-299, pi.
7,figs.5-6.
Coccolithus aff. C. helis Gaetnee 1968, p. 18, pi. 4, fig. 8.
122 Shiro NlSHlDA
Description : Placolith, elliptical in plane view with closely appressed shield convex distally, concave proximally and a small central opening. Proximal shield smaller. Central opening is spanned by delicate crossbars along the short and long axes.
Diameter of the hypotype is about 9. 9,« along the longitudinal axis. Diameter of the central opening is approximately 2. 0/^.
Hypotype : PL E, Fig. 5 (NC1R-62).
Remark : Coccolithus helis is reported from the Danian.
Coccolithus pelagicus (WALLICH) SCHILLER 1930 PL H, Figs. 1-4 & PL ffi, Figs. 1 & 8-9
Coccosphaera pelagica Wallich 1877, p. 348, pi. 17, fig. 1.
Coccolithus pelagicus (Wallich) Schiller ; Black, 1965, p. 133, fig. 4 ; Haq, 1966, p. 31, pi. 1, fig. 5 ; McIntyee & Be, 1967, pp. 569-570, pi. 8, figs. A-C ; McIntyre et al., 1967, p. ll, pi.
4,figs.a-b.
Description : Placolith, oval in plane view with wide shields convex distally, concave proximally and a narrow elliptical central pore. In the distal view the outer elements have radial suture with dextral imbrication. In the center a number of rhomboidal elements arranged helically. The proximal shield is smaller and the fine striae incline dextrally. Normally there is a bar made of rhombic elements that croses the pore at its center and right angles to the long axis of tha pore (vid.
PL n,Figs.2&3).
Length of the distal shield of the hypotypes ranges from 7.5/^ to 10.5/*.
Width ranges from 6.0/n to 8.7/*.
Hypotype: PL H, Figs. 1-4 & PL El, Figs. 1 & 8-9. (I-1; NC9R-38,
H-2;NC9R-149, II-3;NC9R-26, H-4;NC9R-118, I-1;NC13R-4, IB-8;
NC1R-17, I-9 :NClR-2).
Remark : Stratigraphic distribution of this species ranges from the Jurassic to the Recent. Living organisms of this species are reported from cold water region and supposed as a indicator of transitional or subarctic condition in both of the Atlantic and Pacific Ocean (MdNTYRE & BE, 1967, & MclNTYRE & LOUISE, 1969).
Coccolithus sp.
PL I,Fig.8
Description : Placolith, elliptical in plane view with closely appressed shields
Nannofossils from Japan I. Miocene Coccolithophorids from Noto, Central Japan 123
convex distally, conave proximally and a oval central opening. A short sturdy bridge transversely span in the central opening. Fine structures on the shield are obscure for the later external calcite deposition on the surface.
Length of the hypotype is 6.5/*. Width is about 5.0^. Longitudinal diameter of the central opening is approximately 2.0/t.
Hypotype : PL I , Fig. 8 (NC9R-48).
Remark : The present specimen partilly resembles to Coccolithus britardcus STRADNER, especially in the features of the central opening and its bridge structure.
But it differs in its width of the shield and reported stratigraphic range. Occurrence of C. britanicus is commonly reported from the Jurassic (STRADNER, 1963 & others).
Genus Cyclococcolithus KAMPTNER, 1954
Cyclococcolithus formosus KAMPTNER 1963 PI. I, Fig. 3
Cyclococcolithus formosus Kamptner 1963, pp. 163-164, text-fig. 20, pi. 2, fig. 8 ; Reinhardt, 1966, p.22,pi.21.
Cyclococcolithus cf. formosus Kamptner ; Cohen, 1965, p. 26, pi. 19, figs, c-e.
Description.' Placolith, circular in plane view with a shield convex distally and a large central pore. Segments petaloid with dextral imbrication in the distal shield. The suture line on the distal surface of the shield is radial for about one- half the distance from the central column and then curves sinistrally. The distal shield composed of about twenty-three segments.
Diameter of the distal shield is about 6.5/*.
Hypotype : PI. HI, Fig. 3 (NC9R-167).
Remark : Stratigraphic distribution of the present species ranges from the Lower Tertiary (before the Upper Eocene) to the Lower Miocene.
Cyclococcolithus sp.
PI. I,Fig.7
Description : Placolith, circular in plane view with closely appressed shields convex distally, concave proximally and a central pore. Both shields are respectively composed of about forty-five wedge-shaped segments. Combined pattern of radial and tangential striae is conspicuous on the proximal surface of the proximal shield.
Diameter of the distal shield is 7.5/*. Diameter of the proximal shield is about 6.0/^. The one of the central pore is l.OA-
Hypotype : PI. I , Fig. 7 (NC13R-21).
124 Shiro Nishida
Genus Discolithina LOEBLICH & TAPPAN, 1963 Discolithina cf. D. cristata (KAMPTNER)
PI. ID, Fig. 10
Coccolithites cristatus Kamptner 1955, p. 20, pi. 3, fig. 28.
Discolithus cristatus Kamptnek 1956, p. 9.
Description : Discolith, elliptical in plane view. The shield has dextral imbrication and the fine structure of the basal part is broken off. Judging from partial observation, the number of segments composing the shield are supposed to be about fifty.
Diameter of the specimen is about 5.0^.
Hypotype : PI. ffl, Fig. 10 (NC9R-151).
Remark : The holotype of this species is reported from the Tertiary of Indonesia.
Disoclithina multipora (KAMPTNER) MARTINI 1965 PL HI, Fig.2
Discolithus mulihiporus Kamptneb ; Stradner, 1964, text-figs. 3-8 ; Stradner & Adamikeh, 1966, p. 340, pi. 3, fig. 1.
Discolithina multipora (Kamptner) Martini ; Martini, 1969, p. 288, pi. 26, figs. 5-6.
Description : Discolith, elliptical in plane view with thick rim and a wide perforated central area. About twenty large pores are distributed in the central area. The rim is composed of fine rhomboidal elements arranged tangentially.
Length of the hypotype is about 7.5p. Width is 5.6/*. Diameter of the pore in the central area is about 0.5/<.
Hypotype : PL I, Fig. 2 (NC1R-48).
Remark : Stratigraphic distribution of this species ranges from the Eocene to the Miocene.
Discolithina sp.
PI. II, Fig.ll
Description : Discolith, elliptical in plane view with wide central area. Fine structures on the discolith are obscure in the present specimen.
Longitudinal diameter of the hypotype is 2.8,«- Width is 1.6/^. Length of the central area is 1.8A-
Hypotype : PL E , Fig.ll (NC9R-101).
Nannofossils from Japan H. Miocene Coccolithophorids from Noto, Central Japan 125
Genus Ellipsoplacolithus KAMPTNER, 1963 Ellipsoplacolithus cf. E. productus KAMPTNER 1963
PI. ffi, Fig. 6
Ellipsoplacolithus productus Kamptner 1963, pp. 172-173, pi. 8, figs. 42 & 44.
Description : Placolith, ellptical in plane view with shields convex distally, concave proximally. Segments petaloid with slightly sinistral imbrication in the proximal shield at the view from the proximal side. Central longitudinal slit is conspicuous.
Longitudinal diameter of the distal shield is approximately 2. 4/«.
Hypotype : PL I, Fig. 6 (NC1R-13).
Remark : Holotype of the present species was reported from a deep-sea core of the Equatorial Pacific.
Genus Helicopontosphaera HAY & MOHLER, 1967 Helicopontosphaera kamptneri HAY & MOHLER 1967
PL HI, Figs. ll-13
Coccolithus carteri (Wallich) Kamptner 1941, p. 93, pi. 8, figs. 134-136.
Helicosphaera carteri (Wallich) Kamptner 1954, p. 22, figs. 17-19 ; Black & Barnes, 1961, p. 139, pi. 22, fig. 1 & pi. 23, figs. 1-2 ; Kamptner, 1963, p. 173, pi. 3, figs. 19 & 21 ; Cohen, 1964, p.
238, pi. 4, fig. 1 ; Cohen, 1965a, p. 340, pi. 2, fig. A ; Cohen, 1965b, p. 21, pi. 17, figs, a-d ; McIntyre & Be, 1967, p. 571, pi. ll, fig. A ; McIntyre et al., 1967, pp. 12-13, pi. 6, figs, a-b ; Cohen & Reinhardt, 1968, p. 298, pi. 20, figs. 5 & 8.
Helicopontosphaera kamptneri Hay & Mohler, 1967, p. 448, pi. 10-ll, fig. 5.
Description : The center of the proximal surface is covered by a large flat ellptical shield, consisting of elongate plates disposed approximately at right-angles to the periphery of the shield. For this arrangement of the plates, they meet at a forcal point of the shield and normally make two wedge-shaped pores. But the present specimen from the Suzu formation have not distinct pore (vid. PI. H , Figs.
ll-13). Surrounding of the central shield is a flange of narrow radial plates.
They wind round the shield dextrally viewing from the proximal side, and form a wing-like expansion. Proximal shield is formed by the tangentially arranged crystals concealing the structure seen on the distal surface except the wing.
Length of the hypotype ranges from 8.2/< to 10.2^. Width ranges from 5.5ft to6.2/t.
Hypotype : PI. ffi, Figs. ll-13 (I-ll >-NC1R-95, lfl-12:NC1R-22, 1-13;
NC1R-8),
126 Shiro NiShida
Remark : Reported stratigraphic distribution of this species ranges from the Paleocene to the Recent.
Genus Tiarolithus KAMPTNER, 1958 Tiarolithus sp.
PL H, Fig.9
Description : Circular shield consisting of about twenty-eight segments with a wide central pore. Wedge-shaped segments imbricate sinistrally. Fine structures in the central pore are obscure.
Diameter of the specimen is about 2.8^. Diameter of the central pore is aboutIfi.
Hypotype : PI. E , Fig. 9 (NC9R-166).
Remark : Precise position on the taxonomy of the specimen is not determinable at present,
Genus Umbilicosphaera LOHMANN, 1902
Umbilicosphaera aff. U. cricota (GARTNER) COHEN & REINHARDT 1968 PI. H, Fig.6
Umbilicosphaera cricota (Gartner) Cohen & Reinhardt 1968, p. 296, pi. 21, fig. 3.
Description : Placolith, elliptical in plane view with closely appressed shields convex distally, concave proximally and a wide central opening. The larger distal shield is composed of about thirty wedge-shaped segments. The proximal shield is narrow in width and composed of short narrow segments.
Length of the hypotype is about I.lfi. Length of the central opening is 1.2ft.
Hypotype : PI. fl, Fig. 6 (NC9R-179).
Remark : Reported stratigraphic distribution of Umbilicosphaera cricota (GARTNER) ranges from the Pleistocene to the Recent.
Umbilicosphaera cf. U. mirabilis LOHMANN 1902 PI. I, Fig.7
Umbilicosphaera mirabilis Loiimann ; Black & Barnes, 1961, p. 140, pi. 25, figs. 4-5.
Description : Placolith, circular in plane view with closely appressed shields convex distally and a wide central pore. Fine structures of the specimen are obscure for the later external calcite deposition on the surface.
Diameter of the hypotype is about A-5ft. Diameter of the central pore is 1.6ft.
Hypotype : PL I, Fig. 7 (NC9R-24).
Remark : Reported stratigraphic distribution of Umbilicosphaera mirabilis ranges from the Pleistocene to the Recent.
Nannofossils from Japan I. Miocene Coccolithophorids from Noto, Central Japan 127
References
Black, M. & B- Barnes (1961) : Coccoliths and discoasters from the floor of the South Atlantic Ocean.
Jour. Roy. Micr. Soc, 80, 137-147.
(1965) : Coccoliths. Endeavour, 93, 131-137.
BoUCHfi, P. M. (1962) : Nannofossiles calcaires du Lutetien du Bassin de Paris. Rev. Micropal., 5, 75- 103,pis.1-4.
Bramlette, M. N. & F. R. Sullivan (1961) : Coccolithophorids and related nannoplankton of the early Tertiary in California. Micropal., 7, 129-188, pis. 1-14.
& E. Martini (1964) : The great change in calcareous nannoplankton fossils between the Maest- richtian and Danian. ibid., 10, 291-322, pis. 1-7.
Cohen, C. L. D. (1964) : Coccolithophorids from two Caribbean deep-sea cores, ibid., 10, 231-250, pis. 1-6.
(1965a) : Coccoliths and discoasters. Some aspect of their geologic use. Geol. en Mijn., 55, 337-344.
(1965b) : Coccoliths and discoasters from Adriatic Bottom sediments. Leidse Geol. Meded., 35, 1-44, pis. 1-25.
& P. Reinhardt (1968) : Coccolithophorids from the Pleistocene deep-sea core CP-28. N. Jb.
Geol. Palaont. Abh., 131, 289-304, pis. 19-21.
Deflandre, G. (1952a) : Classe de Coccolithophorides. In : Grasse, P. P. (Ed.), Traite de Zoologie, 1, 439-470.
(1952b) : Sous-embranchement des flagelles. In : Piveteau, J. (Ed.), Traite de Paleontologie, 1, 99-130.
Gartner, S. Jr. (1968) : Coccoliths and related calcareous nannofossils from upper Cretaceous deposits of Texas and Arkansas. Univ. Kansas Paleontol. Contr., 48, 1-56, pis. 1-28.
Haq, U. Z. B. (1966) : Electron microscope studies on some upper Eocene calcareous nannoplankton from Syria. Stockholm Contr. Geol., 15, 23-37, 6pls.
Hay, W. W., H. P. Mohler, P. H. Roth, R. R. Schmibt & J. E. Boudreaux (1967) : Calcareous nannoplankton zonation of the Cenozoic of the Gulf Coast and Caribbean Antillean Area and transoceanic correlation. Trans. Gulf Coast Assoc. Geol. Soc, 17, 428-459, 13pls.
Kamptner, E. (1941) : Die Coccolithineen der Sudwestkilste von Istrien. Naturh. Mus. Wien, Ann., 51, 54-149, pis. 1-15.
(1954) : Untersuchungen iiber den Feinbau der Coccolithen. Arch. Protistk., 100, 1-90.
(1955) : Fossile Coccolithineen-Skelettreste aus Insulinde. K. Nederl. Akad. Wetensch., Afd.
Naturk., Verh., ser. 2, 50, 2, 1-105, pis. 1-9.
(1956) : Zur Systematik und Nomenklatur der Coccolithineer. Osterreich. Akad. Wiss., Math.- Naturw. KL, Anz., 93, 4-ll.
(1963) : Coccolithineen-Skelettreste aus Tiefsee ablagerungen des Pazifischen Ozeans. Naturh.
Mus. Wien, Am., 66, 139-204, 9pls.
Levin, H. L. & A. P. Joebgeb (1967) : Calcareous nannoplankton fxom the Tertiary of Alabama, Micropal., 13, 163-182, pis. 1-4,
128 Shiro NlSHlDA
Lohmann, H. (1902) : Die Coccolithophoridae, eine Monographie der Coccolithen bildenden Flagellaten, zugleich ein Beitrage zur Kenntnis des Mittelmeerautriebs. Arch. Protistk., 1, 89-165, pis. 4-5.
Martini, E. (1969) : Nannoplanktons aus dem Miozan von Gabon. N. Jb. Geol. Palaont. Abh., 132, 285-300, pis. 26-29.
McIntyre, A., A. W. H. Be & R. Preiktas (1967) : Coccoliths and Pliocene-Pleistocene boundary.
Progress in Oceanography, 4, 3-24.
& (1967) : Modern Coccolithophoridae of the Atlantic Ocean-I. Placoliths and Cyrtoliths.
Deep-Sea Res., 14, 561-597, pis. 1-12.
& H. Louise (1969) : Biogeography of modern Pacific Coccolithophoridae. (abstract). Jour.
Paleontl., 43, 893.
Nishida, S. (1968a) : Preliminary note on the calcareous sediments and nannofossils in Noto Peninsula, Japan. Bull. Nara Univ. Educ, 16-2, 53-57, lpl. (in Japanese).
& M. Shimakura (1968b) : Coccoliths from the Iida diatomaceous mudstone, Noto. (abstract).
Jour. Geol. Soc. Japan, 74, 98-99. (in Japanese).
(1969) : Nannofossils from Japan I. Discoasters from Noto. Trans. Proc. Palaeont. Soc. Japan, N. S., 75, 136-152, pis. 15-17.
Reinhardt, P. (1966) : Zur Taxonomie und Biostratigraphie der fossilen Nannoplanktons aus dem Malm, der Kreide und dem Altteriar. Freiberg. Forsch. Heft., C153, 5-109, 23pls.
Stradner, H. (1963) : New contributions to Mesozoic stratigraphy by means of nannofossils. 6tk World Petr. Congr., sec. 1, pap. 1, 1-16.
(1964) : Die Ergebnisse der Aufschlussarbeiten der OMVAG in der Molassezone Niederosterreichs in den Jahren 1957-1963. Ergebnisse der Nannofossil-Untersuchungen (Teil 1). Erdoel-Z., 80, 133-139.
& D. Adamiker (1966) : Nannofossilen aus Bohrkerner und ihre elektronmikroskopische Bearb- eitung. ibid., 82, 330-341, 3pls.
Sullivan, F. R. (1964) : Lower Tertiary nannoplakton from the California Coast Range. I. Paleocene.
California Univ., Publ. Geol. Sci., 44, 163-228, pis. 1-12.
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Nannofossils from Japan jn. Miocene Coccolithophorids from Noto, Central Japan 129
Explanation of Plates
Electronmicrographs of carbon replica.
All figures presented are magnified to about 6000 times.
Plate I Fig. 1 Coccosphere
A coccosphere of Coccolithus doronicoides Black & Barnes. NC9S-90. Iida diatomaceous mudstone. Morikoshi, Suzu City.
Fig. 2 Coccosphere
A coccosphere of Umbilicosphaera cf. U. mirabilis Lohmann. NC9R-2. Iida diatomaceous mudstone. Morikoshi, Suzu City.
Fig. 3 Coccosphere
A coccosphere of undeterminable species. NC9R-175. Iida diatomaceous mudstone. Morikoshi, Suzu City.
Fig. 4 Coccolithus doronicoides Black & Barnes
Proximal view. NC9R-39. Iida diatomaceous mudstone. Morikoshi, Suzu City.
Fig. 5 Coccolithus doronicoides Black & Barnes
Proximal view. NC9R-94. Iida diatomaceous mudstone. Morikoshi, Suzu City.
Fig. 6 Coccolithus doronicoides Black & Barnes
Proximal view. NC9R-98. Iida diatomacaeous mudstone. Morikoshi, Suzu City, Fig. 7 Cyclococcolithus sp.
Proximal view. NC13R-21. Akagami shale. Awazu, Suzu City.
Fig. 8 Coccolithus sp.
Distal view. NC9R-48. Iida diatomaceous mudstone. Morikoshi, Suzu City.
Fig. 9 Coccolithus consuetus Bramlette & Sullivan
Distal view. NC9R-46. Iida diatomaceous mudstone. Morikoshi, Suzu City.
Fig. 10 Coccolithus doronicoides Black & Barnes
Proximal view. NC9R-10. Iida diatomaceous mudstone. Morikoshi, Suzu City.
Fig. ll Coccolithus doronicoides Black & Barnes
Proximal view. NC9R-96. Iida diatomaceous mudstone. Morikoshi, Suzu City.
Plate n Coccolithus pelagicus (Wallich) Schillek
Distal view. NC9R-38. Iida diatomaceous mudstone. Morikoshi, Suzu City.
Coccolithus pelagicus (Wallich) Schilleb
Proximal view. NC9R-149. Iida diatomaceous mudstone. Morikoshi, Suzu City.
Coccolithus pelagicus (Wallich) Schillek
Proximal view. NC9R-26. Iida diatomaceous mudstone. Morikoshi, Suzu City.
Coccolithus pelagicus (Wallich) Schilleb
Proximal and diagonal view. NC9R-118. Iida diatomaceous mudstone. Morikoshi, Suzu City.
Coccolithus aff. C. helis Stradnek
Proximal view. A part of the proximal shield is broken off. NC1R-62. Hojuji diatomaceous mudstone. Uwado-cho, Suzu City.
Umbilicospaera aff. U. cricota (Gartner) Cohen & Reinhaedt
Proximal view. NC9R-179. Iida diatomaceous mudstone. Morikoshi, Suzu City.
130 Shiro NlSHlDA
Fig. 7 ? Umbilicosphaera sp.
NC1R-30. Hojuji diatomaceous mudstone. Uwado-cho, Suzu City.
Fig. 8 Coccolithus doronicoides Black & Barnes
Proximal view. NC9R-76. Iida diatomaceous mudstone. Morikoshi, Suzu City.
Fig. 9 Tiarolithus sp.
NC9R-166. Iida diatomaceous mudstone. Morikoshi, Suzu City.
Fig. 10 Coccolithites sp.
NC9R-168. Iida diatomaceous mudstone. Morikoshi, Suzu City.
Fig. ll Discolithina sp.
NC9R-101. Iida diatomaceous mudstone. Morikoshi, Suzu City.
Fig. 12 Coccosphere
A part of a coccosphere of Coccolithus pelagicus (Wallich) Schiller. NC9R-60. Iida diatomaceous mudstone. Morikoshi, Suzu City.
Plate I Fig. 1 Coccolithus pelagicus (Wallich) Schiller
Proximal view. NC13R-4. Akagami shale. Awazu, Suzu City.
Fig. 2 Discolithina muitipora (Kamptner) Martini
NC1R-48. Hojuji diatomaceous. mudstone. Uwado-cho, Suzu City.
Fig. 3 Cyclococcolithus formosus Kamptner
Distal view. NC9R-167. Iida diatomaceous mudstone. Morikoshi, Suzu City.
Fig. 4 Calcitrema sp.
NC4R-68. Hojuji diatomaceous mudstone. Hojuji, Uwado-cho, Suzu City.
Fig. 5 Calcitrema sp.
NC1R-51. Hojuji diatomaceous mudstone. Uwado-cho, Suzu City.
Fig. 6 Ellipsoplacolitkus cf. E. productus Kamptner
Distal view. NClR-13. Hojuji diatomacaeous mudstone. Uwado-cho, Suzu City.
Fig. 7 Umbillicosphaera cf. U. mirabills Lohmann
Distal view. NC9R-24. Iida diatomaceous mudstone. Morikoshi, Suzu City.
Fig. 8 Coccolithus pelagicus (Wallioh) Schiller
Proximal view of the distal shield. NC1R-17. Hojuji diatomaceous mudstone. Uwado-cho, Suzu City.
Fig. 9 Coccolithus pelagicus (Wallich) Schiller
Proximal view of the distal shield. NC1R-2. Hojuji diatomaceous mudstone. Uwado-cho, Suzu City.
Fig. 10 Discolithina cf. D. cristata (Kamptner)
NC9R-151. Iida diatomaceous mudstone. Morikoshi, Suzu City.
Fig. ll Helicopontosphaera kamptneri Hay & Mohleb
Distal view. NC1R-95. Hojuji diatomaceous mudstone. Uwado-cho, Suzu City.
Fig. 12 Helicopontosphaera kamptneri Hat & Mohler
Distal view. NC1R-22. Hojuji diatomaceous mudstoae. Uwado-cho, Suzu City.
Fig. 13 Helicopontosphaera kamptneri Hay & Mohler
Distal view. NC1R-8. Hojuji diatomaceous mudstone. Uwado-cho, Suzu City.
