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‘JURASSIC BIVALVIA AND
TROPODA FROM TANGANYIKA
_ AND KENYA

bh RY COX

‘BULLETIN OF

eae Supplement 1
| LONDON > 1965

PeRASSIC BIVALVIA AND GASTROPODA
FROM TANGANYIKA AND KENYA

BY

EESLIE REGINALD COX, M.A., Sc.D.,F.B-S.
kul

“Vv

30 Plates ; 2 Text-figures

BULLETIN OF
THE BRITISH MUSEUM (NATURAL EST ORY)
GEOLOGY Supplement 1 |
LONDON : 1965

THE BULLETIN OF THE BRITISH MUSEUM
(NATURAL HISTORY), instituted in 1949, 18 issued
in five series corresponding to the Departments of
the Museum, and an Historical series.

Parts will appear at irregular intervals as they become
veady. Volumes will contain about three or four
hundred pages, and will not necessarily be completed
within one calendar year.

In 1965 a separate Supplementary series of longer
papers was instituted, numbered serially for each
Department.

This paper is Supplement No. 1 of the Geological
(Palaeontological) series. The abbreviated titles of
periodicals cited follow those of the World List of
Scientific Periodicals.

© Trustees of the British Museum (Natural History) 1965

TR Sise Ss OP EE
BRITISH MUSEUM (NATURAL HISTORY)

Issued October, 1965 Price: 76

HeIRASSIC BIVALVIA AND- GASTROPODA
FROM TANGANYIKA AND KENYA

By L. R. COX
CONTENTS
Page

I INTRODUCTION . : 4
Il HISTORY OF INVESTIGATION OF Jurasstc Motiusca OF Bast Ae RICA 5

Ill East AFRICAN JURASSIC BIVALVE AND GASTROPOD FAUNAS AND
THEIR CHARACTERISTICS . E ‘ : : : : : 10
IV SYSTEMATIC DESCRIPTIONS. : : F ‘ : : 25
V_ List OF FOSSIL LOCALITIES, WITH SPECIES COLLECTED FROM EACH . 174
VI REFERENCES . : : ; : : , , : : 198

SYENOW SES

Jurassic Bivalvia and Gastropoda from Tanganyika and Kenya in the collections of the
British Museum (Natural History) are described in this memoir. The bulk of the material has
come from three sources, the British Museum East Africa Expeditions (1924-31), the Geological
Survey Departments of the two territories concerned, and the B.P.—Shell Petroleum Development
Company of Tanganyika, Ltd. 207 species of Bivalvia and 56 of Gastropoda are described, but
among them are ro identified only generically and 12 of which the specific identifications have
been qualified or queried. The totals include 84 new species of Bivalvia and 33 of Gastropoda,
while one bivalve species has been re-named on account of homonymy. One new subgenus of
Bivalvia, A fricomiodon (subgenus of Eomiodon), and one new genus of Gastropoda, A fricoconulus,
are erected.

The strata which have yielded the specimens described range from Toarcian to uppermost
Jurassic in age. The occurrence of many species found also in the European Jurassic confirms
evidence from other parts of the world of the very wide geographical distribution of such forms.
These widespread species are particularly abundant in the Callovian and Oxfordian material.
At the same time, the existence of a subprovince which included countries surrounding the
western part of the Indian Ocean (Madagascar, Arabia, India and Pakistan, as well as East
Africa) is indicated by the occurrence of a number of well-characterized species found in one or
more of the other countries mentioned, but not in Europe. Ignoring the qualifications (“ cf.”
and “ aff.’’) of a few identifications, these results are summarized in the following table:

Species Species
Species New known Species found in
Geological Stage heve species only from found in India etc.
vecorded E. Africa Europe but not
Europe
Kimmeridgian . ; 92 35 56 32 3
Oxfordian . , : 53 16 21 27 5
Callovian . : , 46 5 8 32 6
Bathonian* , , 10 4 4 4 2
Bajociant . 5 F 44 29 27, 12 4
Toarcian . 30 22 22 7 I

*Including Asaharbito Beds.
+Including Pindiro Shales.

4 JURASSIC BIVALVIA AND GASTROPODA
Ll INTRODUCTION

DuRING the past 40 years numerous fossil invertebrates from the Jurassic rocks of
East Africa have been added to the collections of the British Museum (Natural
History). This material has come from several sources. From 1924 to early in
1931 the Museum sent a series of expeditions to collect from the dinosaur beds of
Tendaguru, Tanganyika, under the leadership of W. E. Cutler, J. Parkinson and
I. W. H. Migeod in succession, and the material brought back to England included
many invertebrate specimens as well as dinosaur bones. [Irom about the same
period to the present day the Geological Survey Departments of Tanganyika and
Kenya have from time to time sent collections of fossils to London for identification,
and the material from these sources which has been deposited in the Museum during
the past few years has been particularly extensive. From 1951 to 1959 the B.P.—
Shell Petroleum Development Company of Tanganyika Ltd. investigated a con-
siderable area of the coastal region of the two territories and a selection from the
Jurassic specimens collected has been generously presented to the Museum. Small
collections from East Africa have also been acquired by the Museum from other
sources. Preliminary reports on some of the Geological Survey material have
appeared in the publications of these institutions, and in a few cases these have
included illustrations of some of the fossils. Otherwise, the only publications
dealing with Jurassic bivalves and gastropods from this region now in the Museum
consist of two short notes by the present writer (Cox, 1937a, 1937b). It has, there-
fore, now seemed appropriate to describe in a single memoir all the East African
Jurassic material belonging to these classes which is now available in London.

This account has been written at a time when there are movements afoot to
stabilize Jurassic stratigraphical nomenclature by international agreement. It
seems probable that the decision may be reached to restrict the range of the Kim-
meridgian stage in accordance with non-British usage, and possible that the term
Portlandian may be abandoned. It is, however, uncertain what stage name (Vol-
gian or Tithonian) will be accepted for Jurassic beds of later date than the restricted
Kimmeridgian. In East Africa ammonite evidence establishes the age of the pre-
Cretaceous marine beds at Tendaguru as Upper Kimmeridgian in the British sense
(Arkell 1956 : 355), and there is no palaeontological evidence for correlating any
deposits with the type Portlandian or with post-Kimmeridgian (sensu anglico)
horizons of the European Tithonian. It has therefore been decided to use the term
Kimmeridgian in the British sense in the present memoir, to dispense with the
terms Portlandian and Tithonian, and merely to allude to very late Jurassic beds,
the exact age of which is unestablished, as “‘ uppermost Jurassic ”’

The writer expresses his great indebtedness to all who have placed specimens and
information at his disposal, particularly successive Directors and members of the
staffs of the Tanganyika and Kenya Geological Surveys, and Dr. F. E. Eames and
his colleagues of the palaeontological staff of the British Petroleum Company, Ltd.
Mr. D. L. F. Sealy, of the Department of Palaeontology of the British Museum

T
Ni «

(Natural History), has drawn the two sketch-maps appearing as text-figures, and

FROM TANGANYIKA AND KENYA 5

Mr. C. P. Palmer, of the same Department, has rendered invaluable assistance with
the preparation of many of the fossil illustrations.

II HISTORY OF INVESTIGATION OF JURASSIC MOLLUSCA OF EAST AFRICA

Knowledge of the Jurassic stratigraphy and palaeontology of East Africa has
been reviewed at rather frequent intervals as it has progressed during the past
hundred years. Successive works which may be particularly mentioned in this
connection are those of Neumayr (1885), Dacqué & Krenkel (1909), Behrend (1918),
Krenkel (1925), Arkell (1956), Aitken (27 Quennell e¢ al., 1956 ; also 7m Quennell
et al., 1957), and Pulfrey (1963). In view of the existence of these works, particularly
the later ones, it is necessary for the purposes of the present memoir to do little
more than summarize the history of the study of the Jurassic bivalves and gastro-
pods of the region, although a few passing references may be made to work on the
ammonites.

The earliest record of the occurrence of marine Jurassic rocks in East Africa was a
short note by Fraas (1859) recording the discovery by a missionary, J. L. Krapf, of
an ammonite at Kisaludini, near Mombasa. This specimen, originally identified
as Ammonites annularis Reinecke, was subsequently described as Perisphinctes
(Virgatosphinctes) krapfi by Dacqué (1910 : 13, pl. 3, fig. 3), who showed that its age
was Upper Oxfordian and not Upper Dogger (Callovian), as supposed by Fraas.

Beyrich (1877, 1878) published two short papers on ammonites which the ex-
plorer J. M. Hildebrandt had sent to him from localities near Mombasa, his con-
clusion being that various stages of the Jurassic are represented in the district. In
the account of his journey Hildebrandt (1879 : 254, 272) mentioned the occurrences
of Jurassic beds in the district. Further south, in Usambara, the northern coastal
district of Tanganyika, fossiliferous rocks now known to belong to the Jurassic were
recorded by the English traveller J. Thomson (1879, 1881), but he thought that their
fossils suggested a Carboniferous age. Farler (1879 : 87) referred to the occurrence
of a fossiliferous pisolitic limestone in the same area but made no suggestion regard-
ing its age.

Baumann (1891 : 4, 116), in his work on Usambara, definitely recorded the pre-
sence of Jurassic rocks in that area but cited none of the included fossils by name,
and in the same year Stuhlmann (1891) referred to the outcrop of a narrow belt of
Jurassic rocks behind the Tertiary formations near Pangani, further south, mention-
ing that they contained ammonites. A number of fossils, mostly ammonites,
collected by Stuhlmann at the locality Mtaru were described by Tornquist (1893),
who assigned an Oxfordian age to them ; no bivalves or gastropods were mentioned.
In the same year, Jaekel (1893) published a short note on some Jurassic fossils from
Usambara sent to Germany by G. Lieder, by then established as official geologist in
what was at that time German East Africa. For the first time reference was made
to some Bivalvia, including an oyster said to be scarcely separable from Ostrea
dextrorsum Quenstedt (a probable synonym of Lopha solitaria (J. de C. Sowerby)),
a Lima and a Pseudomonotis?, neither identified specifically. An Upper Jurassic
age was assigned to these forms. In the next year Stuhlmann himself (1894a, 5)

6 JURASSIC BIVALVIA AND GASTROPODA

published two short papers in which he referred to the presence of Jurassic rocks
in the hinterland of Dar es Salaam and Bagamoyo, mentioning the occurrence of
fossil molluscs in them without citing any specific names.

Futterer (1894) reviewed occurrences of Jurassic rocks in the hinterland of Mom-
basa, Tanga, Saadani and Dar es Salaam in the light of fossils sent to Germany by
Hildebrandt, Lieder and von dem Borne. Although mainly devoted to ammonites,
thought to belong to stages ranging from Callovian to Kimmeridgian or possibly
Tithonian, this paper may be noted particularly as containing the description of the
first supposedly new bivalve species from the East African Jurassic. It was a
Chlamys described (Futterer 1894 : 91, pl. 5, figs. 4, 4a) as Pecten bipartitus and
came from beds at Mkusi', near Tanga, thought to be Oxfordian in age. In the
present work it is suggested that the form in question should be regarded as a syno-
nym of the European species Chlamys subtextoria (Minster).

The most important contribution to the Mesozoic palaeontology of East Africa
that had so far appeared was Miiller’s (1900) description of the fossils collected by
W. Bornhardt. This material came from 23 localities in Tanganyika. The beds at
nine of these were assigned to various stages of the Jurassic and those at 14 to the
Cretaceous, but it has since been suggested that two of the 14 belonged to the upper-
most Jurassic and a third to an earlier stage of that system. Most of the Jurassic
localities were situated in the hinterland of Kiswere, in the southern part of the
territory, but one lay to the north-west of Kilwa and others in the hinterland of
Dar es Salaam and Bagamoyo. The Jurassic bivalves and gastropods described by
Miller included a number of forms definitely or tentatively referred to species pre-
viously known from Europe, but the following were regarded as new: Cucullaea
lasti, Isocardia subtenera, Ceromya aequatorialis, Avicula liebertt, Arca uitenhagensis,
Trigoma beyschlagi, Protocardia schencki, Exogyra solea, Straparollus suprajurensis,
Nerinea crednert. In the present memoir some of these are regarded as synonyms
of species which had been described previously, and one or two are recorded from
further localities ; five, however, have not been encountered in the material studied.

A note published by Menzel (1902) dealt with Jurassic fossils collected by Dantz
in Tanganyika. These included a number of bivalves, some of which were referred
to species already known from Europe ; two, however, to which the new names
Pecten muellert and Gervillia dantz were assigned, but which are not identifiable from
the brief descriptions, were recorded from beds thought to be Bathonian in age at a
locality near Kibwendere on the Ngerengere river. Koert (1904) recorded the
presence of Callovian beds, identified by their ammonites, near Tanga, but did not
list any other mollusca. Fraas (1908a) gave an account of his observations on the
dinosaur beds at Tendaguru and neighbouring localities in the Lindi hinterland,
mentioning the abundance of a trigoniid which he recorded as Tvigonia beyschlagi
Miller, and referring also to a limestone full of nerineids. He considered all the
beds to be Cretaceous in age. The same author (1908d) also published a short
account of observations on Jurassic rocks exposed along the railway lines running
inland from Dar es Salaam and from Mombasa respectively. Among the sections

‘See Aitken, in Quennell e/ al., 1956 : 157.

FROM TANGANYIKA AND KENYA 7

of beds illustrated was one near Pendambili (now Magindu) station?, from which an
engineer, Kinkelin, had forwarded a series of fossils to Germany. E. Dacqué’s
determinations of the fossils from this locality, which included a few bivalves, were
cited in the paper.

In 1910 Dacqué published a memoir on the Jurassic fossils from Mombasa and
from the Pendambili quarry which Fraas, Kinkelin, and others had collected. The
Mombasa material consisted only of cephalopods of Upper Jurassic age. The
Pendambili fossils, which were evidently Callovian in age, included a number of
bivalves, some of which were referred to species already known from Europe.
Among them, however, was a new astartid, Astarte muellert, considered to be identical
with a form from southern Tanganyika which Miller (1900 : 534, pl. 17, fig. 7) had
figured under the name Astarte sp. In the same year Krenkel (1910) published an
account of invertebrate fossils collected by Fraas from the neighbourhood of Tenda-
guru. These were still all considered to be Cretaceous in age, but included some
forms now known to have come from Upper Jurassic beds. Among the last were the
supposedly new species Avicula tschingiva, Pinna “‘g. miillerv’’, Perna tendagura, and
Trigonia matapuana, the last founded on what was probably a young specimen of
the “‘ Trigonia smeet’’ group.

The scientific results of the German expeditions (1909-12) to collect from the
dinosaur beds of Tendaguru were published in 1914. Dietrich, in his account of the
gastropods, described the following new species of Upper Jurassic age : Rhytidopi-
lus obliquus, Physa tendagurensis, Patella kindopensis, Nerita (Lissochilus) stremmet,
Pseudomelania (Oonta) recki, and Nerinea hennigi. He also recorded the common
Tendaguru nerineid under the name Nerinella crednert (Miller), the original type-
specimens of which had come from beds of Callovian age. At the same time Hennig
(19146) described the bivalves of the saurian beds, apart from the trigoniids, which
were dealt with in a separate paper by Lange (1914). Hennig recorded a number of
species already known from the Jurassic of Europe, but described three supposedly
new forms, Cucullaea irritans, Gryphaea bubo, and Pseudomonotis tendagurensis.
Lange referred the common trigoniid from the Tendaguru series to the species
Trigoma smeet J. de C. Sowerby, originally described from India, placing T. beyschlagi
Miller in its synonymy, and a second Jurassic species was described by him under
the new name T. dietrichi.

In a subsequent paper Hennig (1917) referred to a small series of molluscs which
he had obtained from black calcareous concretions occurring in a shale formation
(the Pindiro Shales) along the Pindiro valley, north-west of Lindi, in southern
Tanganyika. The specimens collected, which were not figured, were recorded as
Gervillia aff. iyaonensis Newton, Cypricardia aff. nuculiformis (Roemer), Neaera sp.,
“Alaria, Gruppe der Al. hamus’’, and “? Cryptaulax, Gruppe der armata Goldf. sp.”’
The age of this assemblage was thought to be most probably ‘‘ Upper Dogger’’. It
is probable that most of the forms recorded belonged to species found in the shales
themselves and described under other names in the present memoir.

*See Aitken, m Quennell ef al., 1956 : 178, footnote, for information about the position of the Pen-
dambili quarry, which was about 2 km. east of Magindu station.

8 JURASSIC BIVALVIA AND GASTROPODA

In the same year Lange (1917) reverted to the subject of the Tendaguru trigoniid
which he had recorded as Trigonia smeet J. de C. Sowerby in 1914. He remarked
that this species appeared to be a characteristic fossil of the Tithonian, and also
noted that there was some similarity between it and a South American form which
Jaworski had described as Trigonia burckhardtt.

Reck (1921) described a small series of molluscs collected along the railway running
inland from Dar es Salaam. The specimens came from a section between 139°5 and
139°75 km. from that town (according to the former alignment of the railway, since
changed), that is, a little to the west of Kidugallo station. In addition to several
forms identified only generically, the species recorded included a representative of
a new genus of Arcticidae (Dietrichia parvula gen. et sp. nov.) and a small gastropod
described as Neritodomus subkidugallensis sp. nov. The fossil evidence was not
clear enough to enable an exact date to be assigned to this bed, but Reck considered
that not only was it the lowest fossiliferous horizon exposed locally, but also that it
was the lowest horizon with marine Jurassic fossils which up to then had been found
anywhere in East Africa. He considered that it might lie close to the boundary of
the Upper Lias and Dogger. In 1924 Hennig published a detailed account of the
Jurassic beds, ranging from the Lower Dogger to the Lower Malm in German termino-
logy, exposed along and near the same railway, between Kidugallo and Ngerengere.
He recorded and in some cases figured a number of bivalve and gastropod species
previously known from Europe or elsewhere, and described the following as new:
Modiola menzeli [Upper Dogger ; not figured], Ostvea (Alectryonia) bornhardti
[Upper Dogger], Isocardia substriata {Callovian], Pteroperna africana |*‘ Lower
Malm ”’], Corbula pseudomucronata [Oxfordian], Antsocardia recki [Oxfordian].

Dietrich (1925) gave an account of fossils collected in the Mandawa-Mahokondo
area of Tanganyika, where the succession of Upper Jurassic beds is entirely marine
and uninterrupted by dinosaur-bearing beds as at Tendaguru. His paper dealt
mainly with the cephalopods, but the small number of bivalves recorded included a
new species, Gryphaea hennigi, thought to be Kimmeridgian inage. Gregory (1927)
placed on record the discovery near Mombasa of a specimen of the species then
known as Parallelodon egertonianus (Stoliczka), already discovered in Somaliland
and Arabia as well as in the Himalayas, where it occurs typically in the Spiti Shales.
Two years later a note by Parsons (1929) recorded the presence of the bivalve
Posidoma cf. ornati Quenstedt in the Miritini Shales (Callovian) of the Mombasa
district.

This period was marked by a renewal, on the part of Kitchin (1926, 1929), of the
discussion initiated by German workers regarding the age of the dinosaur beds at
Tendaguru. Kitchin (1929 : 208), as the result of his work on the Cutch Jurassic
bivalves, had concluded erroneously that T7igonia smeei occurs in that area in Lower
Cretaceous beds, and was therefore loath to accept the conclusion that the “7.
smeet’’ beds at Tendaguru belonged to the Upper Jurassic, particularly as certain
species (Tvigonia ventricosa (Krauss), Seebachia bronni (Krauss), Astarte herzogi
(Goldfuss) and Gervillia dentata (Krauss)) originally described from the Lower Cre-
taceous Uitenhage beds of South Africa had been recorded from them. Ammonites

FROM TANGANYIKA AND KENYA 9

which Spath had pronounced to belong to the Middle Kimmeridgian had, it is true,
also been found at Tendaguru, but Kitchin suggested that these were derived speci-
mens and maintained that all the beds exposed there belonged to the Lower Cre-
taceous. This contention evoked rejoinders from Dietrich (1927) and Hennig (1927).
It was, however, not long before Spath showed that in India 7. smeez occurs in
Oxfordian and not in Lower Cretaceous beds, and the dispute about the beds at
Tendaguru was not continued. Actually, the records of Uitenhage species from the
“T. smeei’’ beds appear to have been unreliable.

In the third of a series of monographs, inspired by J. W. Gregory, on collections
of fossils from N.E. and E. Africa which had been presented to the Hunterian
Museum, Glasgow University, Weir (1930) described a series of molluscs and brachio-
pods from the Mombasa district, largely collected by Miss M. McKinnon Wood.
The formations from which the material described was collected ranged from the
Kambe Limestone (Upper Bajocian-Bathonian) to the Changamwe Shale (Upper
Oxfordian-Kimmeridgian). Bivalves described included a number of forms assigned

either definitely or with qualification to European species and no new species were
described.

An important monograph by Dietrich (1933) supplemented the earlier works deal-
ing with ammonites and bivalves collected by the German expeditions to Tendaguru.
‘gi bivalves (53 from the Upper Jurassic and 38 from the Cretaceous) were recorded
in this work, the Jurassic forms including the following new species or varieties :
Lithophaga suboblonga, Oxytoma inequivalvis var. hennigi, Stegoconcha solida var.
tendagurensis {previously described by Krenkelas Pinna g. miilleri|, Pecten (Chlamys)
curvivarians, Alectryonia hennigi, Epithippopodium quenstedti, Astarte reckt, Astarte
subobovata, Astarte krenkeli, Astarte weissermeli, Seebachia janenschi, Corbis (Sphaera)
subcorrugata, Cardium (Tendagurium) propebanneianum, Arcomya (Pachymya?)
robustissima.

A memoir by Hennig (1937) on the sedimentary formations of the Lindi-Kilwa
hinterland included a palaeontological section in which, in addition to a number of
previously known forms, the following new gastropod and bivalve species were
described: Nummocalcar (Platybasis) dietricht [Kimmeridgian, Tunduru}, Clavotri-
gonia discordans |‘ Trigonia smeei’’ bed, Tunduru]}, Lima matumbiana | Dogger,
Matumbi]. In the same year the present writer (Cox 19374, b) published two papers
in which a few bivalves collected by G. M. Stockley, of the Tanganyika Geological
Survey, were described. A new subgenus, /udogrammatodon, was founded for the
reception of the Indian Jurassic species Cucullaea virgata J. de C. Sowerby and rela-
ted forms, and a new species, Grammatodon (Indogrammatodon) stockleyi, was
described from beds of Callovian age about 11 miles S.E. of Lugoba, Tanganyika.
A new trigoniid species, Tvigonia tealei, was based on specimens from the same
locality, and was also recorded, with several other species, from Callovian beds east
of Magindu station on the Tanganyika Central Railway.

A second collection made by Miss M. McKinnon Wood from the coastlands of
Kenya included material dealt with by Weir in a further paper (1938). The Kambe

10 JURASSIC BIVALVIA AND GASTROPODA

Limestone, now definitely established by ammonites to include both Upper Bajocian
and Bathonian horizons, was the source of most of the material in this collection, but
there were also specimens from higher horizons of the Jurassic. Weir’s paper
included descriptions of the following new species: Nucula woodae [Kambe Lime-
stone], Nucula (Palaeonucula) gregoryt {Miritini Shales (Callovian)|, Lopha krumbeckt
(Oxfordian-Kimmeridgian], Chlamys (Aequipecten) spathi [Kambe Limestone],
Plesiopecten kenyana {Kambe Limestone], Lima (Pseudolimea?) woodae [Kambe

Limestone].

A series of bivalves and gastropods collected mainly from the locality Cud-
Finagubi, about 3 miles S. of Mandera, in N.E. Kenya near the frontier with Somalia,
formed the subject of a series of notes by Venzo (1942a, 6, 1943, 1944a-c, 1945),
followed by a larger memoir (Venzo 1949). About half the bivalves were identified
(some with qualification) with previously described species and it was concluded
that the age of the assemblage was Bathonian. Twenty species, a few with nume-
rous named varieties, were described as new. Later field work has led to the con-
clusion that the beds yielding this assemblage belong to a horizon very high in the
Jurassic and that some of Venzo’s specific identifications are to be queried. The
age of the Cud Finagubi assemblage is discussed later in the present memoir (p. 24).

Several reports of the Kenya Geological Survey published from 1952 onwards
have included lists of Jurassic bivalves and gastropods, mainly from N.E. Kenya,
based partly on identifications by the present writer, and in two of these (Saggerson
& Miller 1957 ; Joubert 1960) some of the specimens have been illustrated photo-
graphically. Of publications of the Tanganyika Geological Survey, particular
reference must be made to the Bulletin by Aitken (1961) dealing with the Mandawa-
Mahokondo area of southern Tanganyika. This work includes a statistical study
of African specimens of the trigoniid subgenus Indotrigonia, which comprises T77-
gonia smeei J. de C. Sowerby and related species. Aitken concludes that the true
T. smeet, which, as already mentioned, occurs typically in India in beds of Oxfordian
age, has not yet been found in East Africa, and that the common species of the
Upper Kimmeridgian beds at Tendaguru is a distinct form to which he assigns the
name Trigoma (Indotrigonia) africana. The following other trigoniids are also
described in the same paper: Tvigonia (Indotrigonia) mandawae sp. nov. [Lower to
Upper Kimmeridgian], 7. (J.) bevschlagi Miller [‘‘ Tithonian’”’}, T. (I.) robusta sp.
nov. [“‘ Tithonian ’’], T. (I.) v-stviata sp. nov. [‘ Tithonian ’’], T. (Tvigonia) tangany-
icensis sp. nov. [Middle or Upper Kimmeridgian], Laevitrigonia curta sp. nov.
(“* Tithonian ’’|], Opisthotrigonia curvata sp. nov. [“ Tithonian’”’]. In addition, many
bivalve species belonging to other families are listed from various horizons.

III EAST AFRICAN JURASSIC BIVALVE AND GASTROPOD FAUNAS
AND THEIR CHARACTERISTICS
Liassic Assemblage
The oldest beds anywhere in Kenya or Tanganyika assignable on fossil evidence to
the Jurassic system are limestones exposed at Didimtu Hill, 2 miles N.E. of Bur
Mayo, in N.E. Kenya. These beds are separated from the ancient rocks of the

FROM TANGANYIKA AND KENYA it

Basement System by the Mansa Guda formation (Ayers 1952: 6; Thompson &
Dodson 1960 : 15), a series of sandstones and conglomerates, some 1300 feet in
thickness, which so far have yielded no fossils. The Mansa Guda formation may be
the equivalent of the Lugh Series of Stefanini, consisting of some 400 ft. of sand-
stones, marls and limestones developed to the east, in Somalia. Stefanini (1932)
recorded a small mussel-like bivalve and a naticiform gastropod from these beds
and thought that their age might be Lower Liassic. The fossils are not, however,
diagnostic and might equally well be of Triassic age. In the coastal area of southern
Kenya the Duruma formation, except for part or all of its top division, the Mazeras
Sandstones, is probably of much the same age as the Mansa Guda formation. In
Tanganyika the Jurassic rocks are underlain by beds of the Karroo System. There
is at present no fossil evidence that the Karroo beds extend above the Trias.

The Lower Toarcian Didimtu Beds of N.E. Kenya were discovered by P. E. Kent
and F. M. Ayers in 1951 and first recorded by the latter (Ayers 1952: 9). They
have been described in more detail by Thompson & Dodson (1960 : 20), who quote
(: 22) a preliminary report on the Bivalvia and Gastropoda by the present writer.
These fossils are described in the present work and listed on p. 189. Of the 30
named species now recorded from Didimtu, 22 are described as new and eight (one
with the qualification “ aff.’’) are referred to forms described previously, one of
which is re-named. Seven of these are also known from Europe. The eighth,
Weyla ambongoensis, a representative of the Pectinidae, was originally described
from Madagascar and is also found in Pakistan and Morocco. It affords somewhat
meagre evidence that a faunal sub-province comprising the western part of the
present Indian Ocean region and extending over northern Africa had come into
existence. Affinities with the Lias of Morocco are also indicated by the occurrence
of the new gastropod genus Africoconulus, the type-species of which occurs in the
Domerian of that country. The Didimtu fauna includes a rather larger assemblage
of Toarcian gastropods and bivalves than the contemporaneous fauna from Mada-
gascar described by Thevenin (19080), which consisted of 18 bivalves and two gastro-
pods.

Bajocian Assemblages

The Upper Bajocian age of beds included in the Kambe Series, developed in the
coastal district of Kenya, was established on the basis of ammonites collected by
Miss M. McKinnon Wood. The bivalves and gastropods from her collections,
amounting to 22 and two species respectively (some, however, identified only generic-
ally), were described by Weir (1930, 1938). No specimens from these beds have been
examined in the course of the present work. The Kambe Limestone is, however,
underlain by the Mazeras Sandstones, yielding fossil wood considered by its most
recent students to be Upper Triassic in age (Caswell 1956 : 16), although it was
thought that the upper limit of the Sandstones might lie within the Lower Jurassic
(Caswell 1953 : 17 ; 1956: 17 ; Williams 1962: 10). A sample of hard sandstone
belonging to this formation and found at the locality Ribe, about 9 miles N.E. of
Mazeras, has yielded a small series of gastropod moulds, one of which is described in

12 JURASSIC BIVALVIA AND GASTROPODA

the present work as Cirrus mazerasensis sp. nov. Unfortunately, this material is in-
sufficient to establish the geological age of the sample, but it is improbable that it is
pre-Jurassic in view of the rareness of Civrus in rocks older than the Lias. It is
suggested that a Bajocian age may be assigned to the sample until further evidence
is forthcoming.

Bajocian depcesits occur along the Tanganyika Central Railway between Ngeren-
gere in the west and a point between Kidugallo and Magindu in the east, but it is
still uncertain where to draw their upper limit. They also crop out in the area to
the north and south. The geology of this district was described by Hennig, who
distinguished (1924 : 114, 121) between the Ngerengere Beds, continental deposits
belonging to the Karroo System and thought by him to be Liassic in age, and the
Ruvu Beds, which he considered to range from the Aalenian to the Oxfordian. No
specimens from “‘ Reck’s fossil bed”’ (see p. 8), thought to be the lowest fossiliferous
horizon of the local Jurassic series, have been examined in the course of the present
work. That the Lower Bajocian (Aalenian) is represented in this area is shown by
Arkell’s (1956 : 330) record of ammonites of this age in carboniferous shales en-
countered in boreholes in search of limestone north of Kidugallo. Some bedding
planes of these shales are covered with specimens of the bivalve Bositra buchi
(Roemer) [| = Posidonia ornati Quenstedt]. The “ Postdonia”’ from Kissemo, N. of
Kidugallo, recorded by Hennig (1924 : 43), may have come from about the same
horizon. The Kidugallo Oolite, a formation overlying “‘ Reck’s fossil bed ”’ and also
included by Hennig in his Lower Ruvu Beds, yielded a number of Pectinidae and
other molluscs recorded by Hennig (1924 : 14-20), but no fossils from this horizon
have been seen by the present writer. Some molluscs now described came, however,
from two small quarries north of Ngerengere Station, where the horizon is close to
the junction of gneiss and sediment and probably fairly low in the local succession of
fossiliferous Jurassic rocks. The bivalves include the species Eomiodon baroni
(Newton) and Bakevellia ivaonensis (Newton), both originally described from Mada-
gascar, the former from the Bathonian, the latter from Middle Jurassic beds the
precise age of which has not hitherto been recorded.

Hennig’s Middle Ruvu Beds and the Station Beds of King (1954 : 15) are approxi-
mately synonymous. Aitken (7m Quennell ef al., 1956 : 180-181) has compiled a
list of their fossils as recorded by Hennig. The majority are probably of Bathonian
age, but those from the more easterly localities (Hennig 1924 : 50-55) may be from
the Bathonian. Of the molluscs described in the present work, it is most probable
that, in addition to those from near Ngerengere, specimens localized as Kidugallo
and as 6 miles N.W., 5 miles N.W., 2} miles N.N.W., 14 miles N.N.W., and 1} miles
E. of that place are all of Bajocian age. The full list of Bajocian species definitely
identified from this area in the course of the present work is, therefore, as follows :

Modiolus anatinus (Smith)
Bositra bucht (Roemer)
Bakevellia vraonensis (Newton)
Lopha gregarea (J. Sowerby)
Trigonia costata Parkinson

FROM TANGANYIKA AND KENYA

Trigoma kenti sp. nov.

Trigonia kidugalloensis sp. nov.
Lucina despecta Phillips

Fimbria kidugalloensis sp. nov.
Pronoella kidugalloensis sp. nov.
Eotrapezium ? kentt sp. nov.
Eonuodon baron (Newton)
Eonuodon tanganyicensis sp. nov.
Corbula eamesi sp. nov.
Pholadomya lirata (J. Sowerby)
Goniomya trapezicostata (Pusch)
Osteomya dilata (Phillips)
Pseudomelania (Oonia) kidugalloensis sp. nov.
Coelostylina stockleyi sp. nov.
Ataphrus aff. acmon (d’Orbigny)

Beds which are probably Bajocian in age (although ammonite evidence on this
point is lacking) are also well developed towards the southern end of the Jurassic

outcrop, in the area N.W. of Lindi.

They consist largely of shales (the Pindiro

Shales of Hennig) but there are also limestone bands and layers of limestone nodules.
The shales, yielding numerous small molluscs, were encountered in trial borings for

oil near Mandawa.

The following list of species described in the present work

supplements (or most probably in part replaces) Hennig’s records of the species
found in these shales, which have been quoted by Aitken (im Quennell e¢ al., 1956 :

175) :

Parallelodon pindiroensis sp. nov.
Modiolus imbricatus (J. Sowerby)
Gervillella orientalis (Douvillé)
Pinna buch Koch & Dunker
Astarte pindiroensis sp. nov.
Astarte kenti sp. nov.

Protocardia bipi sp. nov.
Protocardia besairiei sp. nov.
Mactromya eamesi sp. nov.
Pronoella pindiroensis sp. nov.
Pronoella putealis sp. nov.
Corbula mandawaensis sp. nov.
Corbula pindiroensis sp. nov.
Corbula tanganyicensis sp. nov.
Ceratomya tanganyicensis sp. nov.
Thracia lens (Agassiz)

Coelostylina mandawaensis sp. nov.
Zygopleura mandawaensis sp. nov.

Procerithium (Rhabdocolpus) mandawaense sp. nov.

Exelissa africana sp. nov.

14 JURASSIC BIVALVIA AND GASTROPODA

Pietteia mandawaensis sp. nov.
Pietteia stockleyi sp. nov.

Pictavia tanganyicensis sp. nov.
Ampullospira besairiet sp. nov.

All except four of the species in the above list are new, and not one occurs in rocks
regarded as Bajocian in S.E. Kenya or in the Kidugallo district of Tanganyika.
Hennig (1917), however, recorded Gervillia aff. tyaonensis Newton from the Pindiro
Shales and the species in question, Bakevellia traonensis, is here recorded from Bajo-
cian beds at Ngerengere, west of Kidugallo. The four previously described species
in the above list from the Pindiro Shales include Pinna buchi1, Thracia lens and Modtio-
lus imbricatus, all of which occur in Europe in both the Bajocian and the Bathonian,
the third (as in East Africa also) ranging up into much later beds. The fourth
species, Gervillella orientalis, was originally described from the Moghara massif of
Sinai, where it is known from later collecting to occur in beds of undoubtedly
Bathonian age. On the other hand, one of the species of the Pindiro Shales now
described as new, Ampullospira besairiei, occurs in beds in Madagascar known to be
Bajocian in age. It would thus appear that the palaeontological evidence as to
whether the Pindiro Shales should be referred to the Bajocian or to the Bathonian
is still inconclusive.

Bathonian Assemblages

Uncertainty about exact delimitation of Bathonian beds from those of earlier and
later stages exists throughout East Africa (cf. Aitken Ig61 : 17-19), and none of
the Mollusca from Tanganyika here described can be unhesitatingly referred to this
stage. It is, however, probable that specimens of Liostrea dubiensis (Contejean)
from I mile and 2 miles west of Magindu Station, on the Tanganyika Central Rail-
way, are from the Bathonian. In the Rahmu area of N.E. Kenya the Murri Lime-
stones of Thompson & Dodson (1958 : 15) are considered to be largely or entirely
Bathonian in age, and have yielded the three species brachidontes (Arcomytilus)
asper (J. Sowerby), Chlamys curvivarians (Dietrich) and Lima (Plagiostoma) biinien-
sis sp. nov., as recorded in the present memoir. Further species from those lime-
stones have been recorded by Weir (1929), and also by Ayers (1952 : 27) on the basis
of identifications by J. A. Douglas, and are listed by Thompson & Dodson (1958 :
1g). Some of the determinations in question, for example, of the Oxfordian species
Cercomya stliqua Agassiz and Exogyra fourtaui Stefanini, appear suspect.

The most interesting assemblage from beds of approximately Bathonian age in
N.E. Kenya is that from the Asaharbito Beds of Thompson & Dodson (1958 : 21).
Not all the provisional identifications originally cited have been confirmed, and the
following revised list from this horizon (omitting forms identified only generically)
can now be presented :

Grammatodon sublaevigatus (Zieten)
Liostrea dubiensis (Contejean)
Trigonia cf. brevicostata Kitchin
Astarte ayersi sp. nov.

FROM TANGANYIKA AND KENYA 15

Sphaeriola madridi (d’ Archiac)
Corbula asaharbitensis sp. nov.
Cuspidaria ayerst sp. nov.

Unfortunately, the Asaharbito Beds have yielded no ammonites and on the basis
of the assemblage listed above it is not possible to say anything more definite than
that they are of Bathonian or Callovian age. The Grammatodon and Sphaeriola,
both species found in Europe, suggest a Bathonian age, but Tvigonia brevicostata
occurs in India in the Callovian. Lzostrea dubiensis is a widely distributed species
with an extended geological range. So far, the two species most characteristic of
the Bathonian rocks of Madagascar and N.W. India, Protocardia grandidiert (Newton)
and Corbula lyrata J. de C. Sowerby, have not been reported from East Africa.
Most of the previously described species identified in the Bathonian of this area have
also been found in Europe. Chlamys curvivarians (Dietrich), however, a form with
an extended geological range, is known only from E. and N.E. Africa, Arabia and
India.

Callovian Assemblages

Callovian rocks are well developed in Tanganyika and Kenya, but in this case
also it is not yet possible to determine exactly their upper and lower limits in the
field. Aitken (1961 : 19-27) has compiled a list of the Mollusca recorded by earlier
workers and collected by himself in beds in S.E. Tanganyika belonging to the “‘ Upper
Bathonian-Oxfordian ”’ part of his Mandawa-Mahokondo Series and has indicated
which of these are probably from the Callovian. The following list of Bivalvia and
Gastropoda from the Callovian of this area is based on material examined by the
present writer and on Aitken’s records, marked with an asterisk in the case of species
not represented in this material (the “‘ Ceromyopsis sp.” of Aitken is here identified
as Ceratomyopsis basochiana (Defrance)) :

Grammatodon (Indogrammatodon) virgatus (J. de C. Sowerby)
*Lycettia indica Cox
*Modtolus glendayi Weir

Eopecten aubryi (Douvillé)

Entolium corneolum (Young & Bird)

Chlamys (Spondylopecten?) badiensis Cox
*Trigonia prova Kitchin

Trigonia elongata J. de C. Sowerby
*Tnigonia aff. propinqua Kitchin
*M yophorella (Orthotrigonia) cf. kutchensis (Kitchin)
*A starte muellert Dacqué

Astarte unilateralis J. de C. Sowerby

Astarte aitkeni sp. nov.
*Ceratomya concentrica (J. de C. Sowerby)
*Ceratomya cf. wimmisensis (Gilliéron)
*Ceratomyopsis basochiana (Defrance)
*Tellurimya telluris (Lamarck)

16 JURASSIC BIVALVIA AND GASTROPODA

Thracia viceliacensis d’Orbigny
Pseudorhytidopilus lonjiensis sp. nov.
Pseudomelania aspasia (d’Orbigny)
Bourguetia saemanni (Oppel)
Harpagodes aft. oceani (Brongniart)
Ampullospira quennelli sp. nov.
Akera tanganyicensis sp. nov.

According to Hennig’s (1924 : 56) profile, Callovian beds are exposed along the
Central Railway in Tanganyika in the cuttings from about 2 km. to nearly 4 km.
east of Magindu Station, but he ignored the fact that Kinkelin’s Callovian fossils,
described by Dacqué (1910), came from very close to Magindu Station (see p. 7).
As summarized by Aitken (7m Quennell e¢ al., 1956 : 180), Hennig (1924 : 57-92)
recorded a number of molluscan species from these beds, but some of the determina-
tions need revision. The following Callovian species from this part of the railway
are recorded in the present memoir :

Liostrea (Catinula) alimena (d’Orbigny)
Trigonia (Frenguelliella) tealer Cox
Astarte muelleri Dacqué

Ceratomyopsis basochiana (Defrance)
Ceratomya pittieri (de Loriol)
Pholadomya lirata (J. Sowerby)

To these may be added the following species, obtained from rocks of about the
same age in the district south of Tarawanda, north of Magindu :
Grammatodon (Indogrammatodon) stockleyi Cox
Meleagrinella echinata (Smith)
Chlamys subtextorta (Minster)
Protocardia consobrina (Terquem & Jourdy)
Neritoma (Neridomus) aft. gea (d’Orbigny)
At localities near Tanga, in the extreme N.E. of Tanganyika, Callovian beds
yielded the following species :
Grammatodon (Indogrammatodon) virgatus (J. de C. Sowerby)
Modiolus bipartitus J. Sowerby
Oxytoma inequivalvis (J. Sowerby)
Chlamys (Spondylopecten?) badiensis Cox
Trigonia (Frenguelliella) tealer Cox
Goniomya trapezicostata (Pusch)

In N.E. Kenya, at localities near the Daua river, the Rukesa Shales of Joubert
(1960 : 13) are dated as Callovian on the evidence of a nautiloid cephalopod referred
to Paracenoceras and of the bivalve assemblage. The presence of Eligmus rollandi
Douvillé suggests that the succeeding Muddo Erri Limestones are at least in part not
later than Callovian, although brachiopod evidence has been considered to indicate
that these beds extend upwards into the Lower Oxfordian. Joubert (1960 : 14-15,
17-18) has compiled lists of molluscs and other invertebrates which have been cited

FROM TANGANYIKA AND KENYA 17,

from these formations. Species represented in the collections examined by the pre-
sent writer may be listed as follows (R, Rukesa Shales ; ME, Muddo Erri Lime-
stones) :

Brachidontes (Arcomytilus) asper (J. Sowerby). ME

Brachidontes (Arcomytilus) laitmairensis (de Loriol). ME

Eligmus rollandi Douvillé. ME

Entolium corneolum (Young & Bird). ME

Eopecten aubryi (Douvillé). R, ME

Camptonectes auritus (Schlotheim). ME

Chlamys curvivarians (Dietrich). R, ME

Lima (Plagiostoma) cf. schardti de Loriol. R, ME

Lima (Plagiostoma) cf. jumaraensis Cox. ME

Lima (Plagiostoma) muddoensis sp. nov. ME

Pseudolimea duplicata (J. de C. Sowerby). ME

Lopha costata (J. de C. Sowerby). R, ME

Lopha gregarea (J. Sowerby). R, ME

Liostrea (Catinula) alimena (d’Orbigny). R, ME

Lucina cf. lirata Phillips. ME

Mactromya aequalis Agassiz. R, ME

Ceratomyopsis basochiana (Defrance). R, ME

Amisocardia minima (J. Sowerby). R

Pholadomya livata (J. Sowerby). R

Pholadomya ovalis (J. Sowerby). ME

Homomya inornata (J. de C. Sowerby). R

Ceratomya concentrica (J. de C. Sowerby). R, ME

Ceratomya wimmisensts (Gilliéron). ME

If these lists of Callovian species are examined it would appear that the East African
assemblages during that stage differed less from those living contemporaneously in
Europe than during the Bajocian and Toarcian. The number of species, whether
new or previously described, unknown from Europe is relatively small. Previously
described species in these lists known only from East Africa are Grammatodon
(Indogrammatodon) stockleyi, Trigonia (Frenguelliella) tealei and Astarte muellert.
Species common to India and East Africa but unknown from Europe are Grammato-
don (Indogrammatodon) virgatus, Lycettia indica, Modiolus glendayi, Eopecten aubryt,
Chlamys curvivarians, Chlamys (Spondylopecten?) badiensis, Trigoma prora, and
Astarte unilateralis (omitting those forms of which the identifications are qualified).
The incoming of the subgenus Jnudogrammatodon, abundant in this region as well as
in Arabia and N.W. India but unknown in Europe, may be particularly noted at this
stage.

Oxfordian Assemblages

Aitken (1961 : 21) has listed a series of ammonites which establish the Upper
Oxfordian age of part of the succession in the area of southern Tanganyika dealt
with in his paper, but the only identified bivalve species collected by him at one of

18 JURASSIC BIVALVIA AND GASTROPODA

the same localities seems to be Grammatodon (Indogrammatodon) virgatus (J. de C.
Sowerby). Material from the same area collected by geologists of the British
Petroleum Company Ltd. includes a number of bivalves and gastropods stated to
come from Upper Oxfordian beds. These may be listed as follows :

Eopecten aubryi (Douvillé)

Pseudolimea mandawaensis sp. nov.

Liostrea polymorpha (Minster)

Astarte sowerbyana Holdhaus

Pholadomya hemicardia Roemer

Pleuromya calceiformis (Phillips)

Aitken’s locality WA. 1817, which he informs me is probably Upper Oxfordian,
has yielded the gastropod recorded herein as Nerinella ?muellert Cox, associated with
Grammatodon (Indogrammatodon) virgatus and an indeterminate perisphinctid
ammonite.

Ammonite-bearing Oxfordian beds in the Bagamoyo hinterland of Tanganyika
have yielded the following species, as also recorded in the present memoir :
Grammatodon (Indogrammatodon) stockleyi Cox
Pteria tanganyicensis sp. nov.
Meleagrinella radiata (Trautschold)
Entolium corneolum (Young & Bird)
Limatula moorei sp. nov.
Gryphaea hennigi Dietrich
Trigonia (Frenguelliella) tealer Cox
Astarte episcopalis de Loriol
Fimbrnia quennelli sp. nov.
Pleuromya uniforms (J. Sowerby)
Goniomya literata (J. Sowerby)
Bourguetia saemanni (Oppel)

No extensive collections of Oxfordian bivalves have yet been made in the coastal
area of Kenya, although a few species were recorded by Weir in the Hunterian
Museum Monographs. In the Tajabba-Wergudud area of N.E. Kenya Saggerson &
Miller (1957 : 13) have referred to the Oxfordian a series of pink and yellow fossili-
ferous limestones to which they have given the name Golberobe Beds. Unfortunate-
ly, however, there is no ammonite evidence for the exact dating of these deposits.
Bivalves from these beds which have been named specifically and are dealt with in
the present memoir are as follows :

Modiolus imbricatus (J. Sowerby)

Modiolus (Inoperna) sowerbianus (d’Orbigny)
Mytilus (Falcimytilus) tifoensis sp. nov.

Mytilus (Falcimytilus) dietrichi sp. nov.
Brachidontes (Arcomytilus) laitmairensis (de Loriol)
Gervillia saggersom sp. nov.

Gervillella siliqua (Eudes-Deslongchamps)

Pee

FROM TANGANYIKA AND KENYA 19

Meleagrinella radiata (Trautschold)
Lopha solitaria (J. de C. Sowerby)
Lopha tifoensis sp. nov.

Liostrea dubiensis (Contejean)
Exogyra nana (J. Sowerby)
Mactromya quadrata (Roemer)
Corbula kailtaensis sp. nov.

Of the above

species, Meleagrinella radiata occurs in abundance at one horizon.

Further north, near the Daua river, the Rahmu Shales of Joubert (1960 : 19) are

referred to the

Oxfordian on ammonite evidence and have yielded the following

bivalves, as now identified :

Mytilus (Falcimytilus) yurensis Roemer
Camptonectes auritus (Schlotheim)
Lima (Plagiostoma) rahmuensis sp. nov.
Lopha gregarea (J. Sowerby)

Lopha solitaria (J. de C. Sowerby)
Lopha cf. intricata (Contejean)

Exogyra nana (J. Sowerby)

Protocardia rahmuensts sp. nov.
Homomya rahmuensis sp. nov.

The succeeding Seir Limestones of Joubert (1960 : 20) have been dated as at least
in part Upper Oxfordian (tvansversarium Zone) on ammonite evidence, although it

is thought that

their upper part may belong to the Lower Kimmeridgian. It is

probable that all of the following forms dealt with in the present memoir, which are
mainly from the Wilderri Hill and Dussé localities, are from the Oxfordian part of

the limestones :

Grammatodon (Indogrammatodon) stockleyi Cox
Grammatodon (Indogrammatodon) irritans (Hennig)
Mytilus (Falcimytilus) jurensis Roemer

Stegoconcha gmuellerit (Krenkel)

Meleagrinella radiata (Trautschold)

Entolium corneolum (Young & Bird)

Camptonectes auritus (Schlotheim)

Eopecten thurmanni (Brauns)

Eopecten aff. albus (Quenstedt)

Chlamys (Radulopecten) inaequicostata (Young & Bird)
Pseudolimea duplicata (J. de C. Sowerby)

Lopha gregarea (J. Sowerby)

Lopha solitaria (J. de C. Sowerby)

Liostrea dubiensis (Contejean)

Astarte huralensis Stefanini

Ceratomya wilderriensis sp. nov.

Mactromya quadrata (Roemer)

Pseudomelania (Rhabdoconcha) wilderriensis sp. nov.

20 JURASSIC BIVALVIA AND GASTROPODA

Bourguetia saemanni (Oppel)

Pietteia dusseensis sp. nov.
Ampullospira dejanira (d’Orbigny)
Globularia phasianelloides (d’Orbigny)
Nerinella cutleri sp. nov.

Species known to occur in Europe in beds belonging to the same stage predominate
in these Oxfordian assemblages. The number of forms described as new is not large,
and previously described species known only from East Africa consist merely of
Grammatodon (Indogrammatodon) stockleyi, Trigonia (Frenguelliella) tealei and
Astarte huralensis. Species common to East Africa and India but unknown from
Europe are Grammatodon (Indogrammatodon) virgatus, Astarte sowerbyana, Eopecten
aubryi, Gryphaea hennigi and Stegoconcha gmuelleri. The subgenus Indogramma-
todon continues to be well represented.

Kimmeridgian Assemblages

In the area of southern Tanganyika dealt with in his memoir Aitken (1961 : 24-31)
distinguishes between the Septarian Marl, yielding Lower Kimmeridgian ammonites
(perhaps also Upper Oxfordian ones at the base of the formation) and the Tendaguru
Series, the lower part of which is classified as Middle-Upper Kimmeridgian and the
upper part as Upper Kimmeridgian-Tithonian. Aitken (1961 : 29) suggests that the
marine beds at Tendaguru itself all belong to the last of these divisions.

The same worker (1961 : 25-26) has compiled a list of bivalves found in the
Septarian Marl based on the records of German workers. No specimens from this
formation have been examined in the course of the present work. He has also
recorded six named species and a number of forms identified only generically from
his Middle-Upper Kimmeridgian division of the Tendaguru Series. No bivalves
from this division have been examined in the course of the present work, but the
following gastropods from Dr. Aitken’s collection are described :

Bathrotomaria aitkent sp. nov.
Lissochilus stremmei Dietrich
Pseudomelania vittata (Phillips)
Pseudomelania (Oonia) attkent sp. nov.
Globularia aff. phasianelloides (d’Orbigny)
Pseudonerinea clio (d’Orbigny)

Nerinella mandawaensis sp. nov.

The presence of Pseudonerinea clio at this horizon is in keeping with its known
occurrences in Europe, but the presence of Pseudomelania vittata, a Cornbrash species
in Europe, in the Kimmeridgian of East Africa, is worthy of comment. As now
suggested in the discussion of this species, it is, however, possible that the distinc-
tions drawn between it and certain related but supposedly distinct species by
European workers are of no significance.

ce

The following is a combined list of the species now recorded from the “ Upper
Kimmeridgian-Tithonian ”’ division of Aitken’s Tendaguru Series in the Mandawa-

FROM TANGANYIKA AND KENYA

Mahokondo area (M) and in the Tendaguru area (T) :

Grammatodon (Indogrammatodon) irritans (Hennig). T
Grammatodon (Indogrammatodon) matapwaensis sp. nov.
Apolinter kindopeensis sp. nov. T

Cucullaea kipandeensis sp. nov. T

Lithophaga suboblonga Dietrich. T

Modiolus bipartitus (J. Sowerby). T

Modiolus (Inoperna) perplicatus (Etallon). T
Mytilus (Falcimytilus) dietricht sp. nov. T
Brachidontes (Arcomytilus) laitmairensts (de Loriol). M
Musculus kindopeensis sp. nov. T

Gervillella aviculoides (J. Sowerby). T

Pinna constantin de Loriol. T

Stegoconcha gmuellert (Krenkel). T

Oxytoma inequivalvis (J. Sowerby). T
Meleagrinella radiata (Trautschold). T

Bositra somaliensis (Cox). T

Entolium corneolum (Young & Bird). T

Chlamys matapwaensis sp. nov. M

Chlamys (Radulopecten) kinjeleensis sp. nov. T, M
Lima (Acesta) kindopeensis sp. nov. T

Lima (Acesta) cutlert sp. nov. T

Pseudolimea duplicata (J. de C. Sowerby). T
Limatula migeodi sp. nov. T

Lopha hennigi (Dietrich). T

Lopha? kindopeensis sp. nov. T

Liostrea dubiensis (Contejean). T

Exogyra nana (J. Sowerby). T

Trigonia migeodi sp. nov. T

Trnigoma (Indotrigomia) africana Aitken [smeez auct.]. T
Trigonia (Indotrigonia) dietrichs Lange. T
Myophorella kiwawaensis sp.nov. M
Laevitrigonia dwantka sp. nov. T

Opisthotrigonia curta (Aitken). M

Hippopodium quenstedti (Dietrich). T

Astarte subobovata Dietrich. T

Astarte reckt Dietrich. T

Astarte sowerbyana Holdhaus. T

Astarte weissermeli Dietrich. M, T

Astarte mandawaensis sp. nov. M

Astarte lonjiensis sp. nov. M

Astarte mitoleensis sp. nov. M

Coelastarte dietricht sp. nov. T

Seebachia janenschi Dietrich. M

dh

21

22 JURASSIC BIVALVIA AND GASTROPODA

Lucina cutlert sp. nov. T

Sphaera subcorrugata Dietrich. T

Protocardia schencki Miller. T

Protocardia suprajurensis (Contejean). M

Protocardia (Tendagurium) propebanneiana (Dietrich). T

Amisocardia kinjeleensis sp. nov. T

Eomiodon dinosaurianum sp. nov. T

Eomiodon (Africomiodon) cutlert sp. nov. T

Homomya hortulana Agassiz. T

Pleuromya uniformis (J. Sowerby). T

Nummocalcar mitoleensis sp. nov. M

Scurriopsis (Dietrichiella) kindopensis (Dietrich). T
- Chrysostoma staffi Dietrich. T

Lissochilus stremmet Dietrich. T

Chartronella mitoleensis sp. nov. M

Pseudomelania (Oonta) dietricht sp. nov. T

Purpuroidea aff. gigas (Thurmann & Etallon). M

Paracerithium lonjiense sp. nov. M

Cossmannea hennigi (Dietrich). T

Nerinella cutleri sp. nov. T

South of the Daua river, in N.E. Kenya, the Hereri Shales of Joubert (1960 : 24)
are referred to the Kimmeridgian mainly on stratigraphical grounds, as no ammonites
identifiable with certainty have been found in them. The following species from
Hereri are recorded in the present work :

Grammatodon (Indogrammatodon) irritans (Hennig)
Mytilus (Falcimytilus) jurensis Roemer

Eopecten thurmannt (Brauns)

Chlamys curvivarians (Dietrich)

Exogyra nana (J. Sowerby)

Protocardia (Tendagurium) bannesiana (Contejean)
Ceratomyopsis striata (d’Orbigny)

Ceratomya excentrica (Roemer)

Bourguetia saemanni (Oppel)

The presence of Protocardia bannesiana appears, from its known European
occurrences, to confirm the Kimmeridgian age of the above assemblage.

In the same area the succeeding Dakacha Limestones are considered by Joubert
(1960 : 28) as “ probably bridging the uppermost Kimmeridgian and the lowest part
of the Tithonian ’’, thus being approximately contemporaneous with the dinosaur
beds of Tendaguru. No ammonites have been found in them, but they have
yielded the following bivalves and gastropods, described in the present work :

Nuculoma (Palaeonucula) bellozanensis sp. nov.
Modiolus virgulinus (Thurmann & Etallon)
Modiolus (Inoperna) perplicatus (Etallon)

a

FROM TANGANYIKA AND KENYA 23

Chlamys curvivarians (Dietrich)

Lima (Plagiostoma) sublaeviuscula Krumbeck
Ctenostreon proboscideum (J. Sowerby)
Lopha gregarea (J. Sowerby)
Rutitrigonia stefaniniu (Venzo)
Mactromya quadrata (Roemer)
Quenstedtia joubertt sp. nov.
Ceratomya excentrica (Roemer)
Pholadomya hemicardia Roemer
Harpagodes thirriae (Contejean)
Globularia hemisphaerica (Roemer)
Globularia hennigi sp. nov.

Trochalia depressa (Voltz)

The assemblage listed above includes none of the characteristic trigoniids or other
elements of the Tendaguru fauna. The occurrence of such species as Modiolus
virgulinus and Harpagodes thirriae, found apparently in the top bed of the Dakacha
Limestones (Joubert 1960 : 27), suggests, from the known European occurrences of
these species, that this bed is Kimmeridgian in age (even in the more restricted
sense) and not later. The presence of Rutitrigonia stefanini, however, serves as a
link between this fauna and that of the beds at Cud Finagubi, discussed a little
later, and is interesting as constituting the earliest known occurrence of Rutitrigonia.

If the East African Kimmeridgian assemblages listed above are considered as a
whole, it will be seen that, while, like those from lower horizons, they include a large
number of species found in the Jurassic of Europe, they have an Indian element
which is rather more pronounced than in the earlier faunas. Affinity with the Indian
fauna is particularly marked among the trigoniids, as seen by the abundance (in
southern Tanganyika) of Indotrigonia and by the presence there of Opisthotrigonia.
Other forms common to the two areas but not found in Europe are A starte sowerbyana
Holdhaus and Stegoconcha gmuelleri (Krenkel). Indogrammatodon continues
to be an important element of the African fauna, although the actual species of
Kimmeridgian age here recorded are distinct from those found in India. The only
known post-Liassic occurrence of the genus Hippopodium is in these East African
beds, while it is interesting to find in the Upper Jurassic of this region the remarkable
astartid genus Seebachia, otherwise known only from South Africa, where it occurs
in the Neocomian. Quite a number of Kimmeridgian species, some here described
as new and others described in earlier monographs by Miller, Dietrich, Hennig and
Aitken, have so far been found only in East Africa.

In the extreme north-east of Kenya a series of beds is developed the age of which
has given rise to some controversy. Termed by Dixey (1948 : 84) the Mandera
Series, these beds have been described by Joubert (1960 : 31-39), who cites
evidence from N.E. of Melka Dakacha that they succeed the Dakacha Limestones
conformably. Some 4o ft. from the base of this series is a fossiliferous deposit
(the basal bed of the subdivision termed by Joubert the Gudediye Beds)
yielding the two bivalve species here described as Tancredia manderaensis sp. nov.

24 JURASSIC BIVALVIA AND GASTROPODA

and Myopholas manderaensis sp. nov. Some hundreds of feet higher (according to
Joubert’s reading of the succession), and separated from this bed by almost unfossili-
ferous deposits, are the Finaguba Beds, which are of interest to palaeontologists as
yielding the assemblage monographed and regarded as of Bathonian age by Venzo
(1949). No specimens from the locality Cud Finagubi itself (the source of most of
Venzo’s material) have been examined, but a short discussion on the age of this
assemblage, based on his illustrations, may be appropriate at this point.

The most abundant fossils are trigoniids, belonging to what I would regard as only
two species, Tvigonia dainellit Venzo (this includes specimens identified by Venzo
as the Callovian species T. brevicostata Kitchin) and T. stefaninit Venzo. T. dainellit
belongs to a subgenus of Tvigonia which has not yet received a name but is represented
in the Upper Jurassic of Europe by a species identified by de Loriol (1868 : 160, pl.
10, figs. 12-16 ; 1872: 295, pl. 16, fig. 20) as Tvigonia truncata Agassiz. In the
Yonne Department of France this species occurs (de Loriol 1868 : 252) only a few
feet below the Cretaceous in beds which appear to be referable to the Portlandian
(as restricted by British geologists), but in the Haute-Marne it occurs (de Loriol
1872 : 498, 499) in beds which would be included in the Kimmeridgian in the British
sense, while in northern Germany Credner (1863 : 22, 36) records it from well down
in the Kimmeridgian. The similarity between 7. dainellit and T. truncata, possibly
amounting to the specific identity of the two forms, thus strongly suggests that the
Finaguba Beds are Upper Jurassic (Kimmeridgian or Portlandian) in age. The
second trigoniid, Tvigonia [now Rutitrigonia] stefaninit Venzo, has already been
commented upon when discussing the fauna of the Dakacha Limestones. Although
belonging to a genus previously reported only from the Cretaceous, the presence of
this species in N.E. Kenya in beds of which the Upper Jurassic age could not be
disputed shows that it does not provide evidence for a Cretaceous age for the
Finaguba Beds. Apart from the trigoniids and some small nondescript oysters,
these beds yielded a large number of internal moulds of bivalve shells not all identifi-
able with any certainty even generically. Venzo’s application to these of the names
of such Bathonian species as Eonavicula eudesii (Morris & Lycett), Anisocardia
loweana (Morris & Lycett), Sphaera madagascariensis (Newton) and Quenstedtia
morrist (Cossmann) has no stratigraphical significance. The same remark applies
to the identification of Grammatodon (Indogrammatodon) virgatus (J. de C. Sowerby)
in this fauna. This subgenus Indogrammatodon is undoubtedly represented by more
than one species, but it is not obvious what specific names should be applied to such
poor material. My present view, taking into consideration the stratigraphical
evidence adduced by Joubert, is that the Finaguba Beds are of Upper Kimmeridgian
if not of still later Jurassic age.

The beds of the Mandera Series are succeeded by deposits for which the term
Marehan Series has been adopted (Saggerson & Miller 1957 : 23 ; Joubert 1960 : 39).
The lower of the two divisions of this series (the Danissa Beds) has been dated as
Lower Cretaceous on palaeobotanical evidence which is not altogether convincing.
A fossiliferous horizon in these beds has yielded a form (Tvigonia dainellit Venzo)

FROM TANGANYIKA AND KENYA 25

already discussed and, limited though this evidence is, it favours the inclusion of
the Danissa Beds, like the Mandera Series below them, in the Jurassic.

IV SYSTEMATIC DESCRIPTIONS

Class BIVALVIA Linnaeus
Superfamily NUCULACEA
Family CTENODONTIDAE Wohrmann 1893
Genus PALAEONEILO Hall 1869

Palaeoneilo asahar bitensis sp. nov.
Pit, fig. 1

Diacnosis. Of medium size for the genus (length of holotype 20 mm.), sub-
elliptical, height about three-fifths of length ; moderately inequilateral, with the
umbo near the anterior third of the length ; inflation rather strong for the genus.
Umbo narrowly rounded, its outline continuous with the almost straight, gently
sloping postero-dorsal outline of the shell ; antero-dorsal outline strongly excava-
ted. Anterior margin broadly rounded, posterior margin more narrowly rounded,
ventral margin strongly and nearly symmetrically convex. Details of ornament
unknown.

HototyrPe. No. L.83864, the internal mould of a left valve. The only specimen.

LOCALITY AND HORIZON. I mile N. of Asaharbito, N.E. Kenya ; Bathonian
[? or Callovian], Asaharbito Beds.

REMARKS. The muscle scars and pallial line are not seen in the holotype, and
impressions of taxodont teeth, while clearly visible along the postero-dorsal and
antero-dorsal margins, are obscured immediately below the umbo. Hence the
reference of the species to the genus Palaeoneilo is based on its general morphology.
The most closely comparable form described from the Middle or Upper Jurassic is
P. longiuscula (de Loriol) (1899 : 159, pl. 10, figs. 23-25, ex Merian MS.), Lower
Oxfordian of Switzerland, which is slightly more elongate.

Family NUCULIDAE
Genus NUCULOMA Cossmann 1907
Subgenus PALAEONUCULA W. Quenstedt 1930
Nuculoma (Palaeonucula) bellozanensis (de Loriol)
Pl. 1, figs. 3a, b
1875. Nucula bellozanensis de Loriol : 138, pl. 17, figs. 16a—c.

MATERIAL. One specimen (no. L.g2293).

26 JURASSIC BIVALVIA AND GASTROPODA

LOCALITY AND HORIZON. 2 miles S. of Melka Dakacha, N.E. Kenya ; Upper
Kimmeridgian, Dakacha Limestones.

REMARKS. This small, evenly ovate specimen, which is just under 10 mm. long,
agrees so well in size and shape with de Loriol’s figures of N. bellozanensis that there
seems no reason to qualify its identification. Of other comparable species, Nucula
saxatilis Contejean (1860 : 284, pl. 21, fig. 13), from the Kimmeridgian of the French
Jura, is less elongate. Nucula ornati Quenstedt (1851 : 528, pl. 44, fig. 7), which, if
Quenstedt’s conception of the species is accepted, ranges in Europe from the Upper
Bajocian to the Oxfordian, has a slightly more prominent umbo. De Loriol’s types
of N. bellozanensis were from the Lower Kimmeridgian of northern France.

I follow Van de Poel (1955) in regarding Palaeonucula as a subgenus of Nuculoma
rather than of Nucula.

Family NUCULANIDAE
Genus NUCULANA Link 1807
Subgenus DACRYOMYA Agassiz 1840

Nuculana (Dacryomya) thompsoni sp. nov.
Plo tyhigs.4¢@, bee

SPECIFIC NAME. After Mr. A. O. Thompson, of the Geological Survey of Kenya,
collector of the holotype.

DiaGNosis. Small (length of holotype 8-6 mm.), pyriform, height two-thirds of
length ; gibbose ; with strongly opisthogyrous, submedian umbones and a short
posterior rostrum the narrow extremity of which is slightly below mid-height.
Postero-dorsal outline strongly concave ; escutcheon broad, cordate, well impressed,
bordered by umbonal ridges. Antero-dorsal outline and anterior and antero-ven-
tral margins forming an uninterrupted, parabolic curve ; posterior end of ventral
margin almost straight. Surface, except for the smooth escutcheon, ornamented
with regular concentric threads, the tops of which are about 0-2 mm. apart.

HoLotyPe. No. LL.35000. The only specimen.

LOCALITY AND HORIZON. Didimtu hill, 2 miles S. of Bur Mayo, N.E. Kenya ;
Upper Lias, Toarcian, Didimtu Beds.

REMARKS. Nuculana zietent (Brauns) (1871 : 373) (non d’Orbigny sp.), Middle
Lias of Europe, is less gibbose and has its posterior rostrum accentuated by a sinus
of the ventral margin. The type species of Dacryomya, Nuculana lacryma (J. de C.
Sowerby) (1824a : 119, pl. 476, fig. 3), Bathonian of Europe and Asia, is less gibbose
and has a more elongate rostrum. In Nuculana gutta (Minster) (= Nucula muc-
vonata Goldfuss 1837, pl. 125, figs. ga—-d, non Sowerby), also known as N. diana
(d’Orbigny), Toarcian and Aalenian of Europe, the postero-dorsal profile is less
strongly concave and the rostrum less well defined.

FROM TANGANYIKA AND KENYA 27

Nuculana (Dacryomya) dodsoni sp. nov.
PE aiies: 2450) *c

SPECIFIC NAME. After Mr. R. G. Dodson, of the Geological Survey of Kenya.

DiaGnosis. Of medium size (length of largest specimens 15 mm.), pyriform, with
the height slightly exceeding half the length ; inflation moderate ; with strongly
opisthogyrous umbones placed just anterior to mid-length and a slightly upcurved
posterior rostrum, the extemity of which is truncated and situated below mid-height.
Postero-dorsal outline strongly concave ; antero-dorsal outline and anterior and
ventral margins forming an uninterrupted, parabolic curve, the ventral margin
convex as far as its posterior extremity. External features of shell unknown.

HOLOTYPE AND PARATYPES. Numerous internal moulds exposed, together with
moulds of a species of Nucula, on a bedding plane of hard brownish limestone. The
holotype (no. L.g8280) is the specimen represented in Pl. 1, fig. 2c.

LOCALITY AND HORIZON. Hagardulun, 25 miles N.E. of Tarbaj, N.E. Kenya ;
Bathonian-Callovian, Bur Mayo Limestones.

REMARKS. Nuculana decorata (Douvillé) (1916 : 61, pl. 5, figs. 56-62), Bathonian
of Sinai, is very similar to this species, but differs in its broader umbonal region.
The widespread Bathonian species N. /acryma (J. de C. Sowerby) has a more sharply
pointed and upcurved rostrum and a more strongly convex ventral margin. The
Callovian species N. moreana (d’Orbigny) (types figured by Cottreau 1925 : 12, pl.
38, figs. 4, 5), which is doubtfully distinct from N. lacryma, differs in the same manner.
The Toarcian-Aalenian species N. rostralis (Lamarck) (type figured by Favre 1914,
pl. 35, figs. 242a, b) has less prominent umbones and a less strongly concave postero-
dorsal margin. The Oxfordian species N. acuta (de Loriol) (1899 : 164, pl. 10, figs.
29-32, ex Merian, MS.) has a narrower posterior extremity, a less concave postero-
dorsal margin, and a distinct sinus at the posterior end of the ventral margin. JN.
matheyr (Rollier) (1912 : 62, pl. 6, fig. 5), another Oxfordian species, has a less
prominent umbo.

Subgenus RYDERIA Wilton 1830

Nuculana (Ryderia) kenyana sp. nov.
Pl. xy figs. 6a, b,c

DiaGnosis. Of medium size (height up to 9 mm., original length possibly three
times that amount), very compressed, inequilateral, with an evidently long posterior
rostrum, the extremity of which, however, is broken away in all the specimens.
Umbones very obtuse, only feebly opisthogyrous, level with the almost straight, sub-
horizontal antero-dorsal margin. Anterior margin flattened, forming an obtuse
angle with antero-dorsal margin ; ventral margin almost straight except for a slight
sinus at beginning of posterior rostrum. Postero-dorsal outline feebly concave ;
escutcheon narrow, shallow, bordered by umbonal ridges which are well defined only

28 JURASSIC BIVALVIA AND GASTROPODA

near the umbones. Surface apparently bearing concentric threads and rugae (the
former, however, almost obliterated by erosion in the available specimens).

HOLOTYPE AND PARATYPES. Nos. LL.35001 and LL.35002-04 respectively, four
specimens in all.

LOcALITY AND HORIZON. Didimtu hill, 2 miles S. of Bur Mayo, N.E. Kenya ;
Upper Lias, Toarcian, Didimtu Beds.

REMARKS. This species differs from the European Upper Liassic species Nuculana
vostralis (Lamarck) (synonym, N. claviformis (J. de C. Sowerby) (1824a : 119, pl. 476,
fig. 2)) in its more compressed form, its almost horizontal and more extended antero-
dorsal margin, and its flatter anterior margin. It is more closely comparable to N.
(Ryderia) doris (d’Orbigny) (= Nucula complanata Goldfuss 1837, pl. 125, figs. I1a—c,
non Phillips) and N. (R.) graphica (Tate) (1870 : 407, pl. 26, fig. 12), both of Liassic
(Pliensbachian) age, but it differs from these species in its more quadrate anterior
end and its flatter ventral margin.

Lemoine (1906 : 112) recorded N. doris from a locality south of Kola, Madagascar,
where it was associated with a Posidonia identified as P. alpina Gras, and where he
thought the beds might be Aalenian in age. As the specimens from that locality
have not been figured, it is impossible to say if they belong to the species now
described.

Subgenus PRAESACCELLA Cox 1940

Nuculana (Praesaccella) camelorum sp. nov.
Pl. 2, figs. 10a, b

1960. Nuculana (Praesaccella) cf. juriana Cox ; Thompson & Dodson : 23 (listed).

DiaGnosis. Of medium size for the genus (length of largest specimen 9-3 mm.),
pyriform, with height about one-half of length ; inflation rather weak ; with
obtusely subangular umbones placed at about anterior third of length and an acutely
pointed posterior extremity which is almost at mid-height. Postero-dorsal outline
straight or slightly concave ; escutcheon narrow, not well seen in available specimens.
Antero-dorsal outline and anterior and ventral margins forming an uninterrupted
curve ; ventral margin in some specimens convex as far as its extremity, in others
with a small sinus at its posterior end. Ornament of very fine, regular concentric
threads.

HOLOTYPE AND PARATYPES. Numerous specimens exposed on a bedding-plane
of hard brownish limestone. The holotype (no. L.g8280) is the one represented in
the bottom right-hand corner of Pl. 2. fig. 10}.

LOCALITY AND HORIZON. Camel track about 5 miles S. of Singu and g miles E. of
Tarbaj, N.E. Kenya ; Toarcian or Bajocian, top of Didimtu Beds.

REMARKS. Nuculana (Praesaccella) juriana Cox (1940 : 33, pl. 2, figs. 6-9), from
the Oxfordian of Cutch, India, is less inequilateral, higher in proportion to its length,
and ornamented with slightly coarser concentric threads. No more closely com-
parable species can be cited.

FROM TANGANYIKA AND KENYA 29

Genus ROLLIERIA Cossmann 1920

Rollieria aequilatera (Koch & Dunker)
Pi. 1, figs. 5a, 0, ¢

1837. Tellina aequilatera Koch & Dunker ; 30, pl. 2, fig. 9.
1850a. Leda delila d’Orbigny : 253.

1869. Leda aequilatera (Dunker & Koch) ; Brauns: 267.

1908a. Leda delila d’Orbigny ; Thevenin : 57, pl. 14, figs. 28-30.

MATERIAL. One specimen (no. LL.35005).

LOCALITY AND HORIZON. Didimtu hill, 2 miles S. of Bur Mayo, N.E. Kenya ;
Upper Lias, Toarcian, Didimtu Beds.

REMARKS. Rollieria includes the small, ovate, equilateral, compressed nuculanids
which range throughout the Jurassic and are difficult to separate into species.
Elsewhere (Cox 1936 : 464) I have applied the name Nuculana (Rollierta) bronni
(Andler) to a species ranging from Lower to Middle Lias. I refer the present Upper
Liassic specimen to R. aequilatera (Koch & Dunker), a species based on an Inferior
Oolite specimen, and I place Leda delila d’Orbigny, based on a Toarcian specimen,
in synonymy, as was suggested by Brauns (1869). The range of R. aequilatera
extends, according to that author, to the orvnatus-beds (Callovian). The specimen
from the Yorkshire Upper Lias figured as Leda aequilatera by Tate (1876, pl. 11,
fig. 10) was wrongly identified and not even a Rollieria. The present specimen from
Kenya, which is 9 mm. long, has the outline of a typical Rollieria, and is referred to
the genus with confidence although it shows no hinge-teeth.

Superfamily ARCACEA
Family PARALLELODONTIDAE Dall 18908
Genus PARALLELODON Meek & Worthen 1866

Parallelodon pindiroensis sp. nov.
Pl. i, figs. 76, b, 6a, 6

DiaGnosis. Of medium size (length of holotype c. 33 mm.), subrectangular to
trapeziform in shape, variable also in ratio of length to height. Umbones rising very
little above hinge-margin, broadly rounded or with a slight median depression ;
beaks at anterior third or quarter of length of shell. Hinge-margin extended
posteriorly as a short, acutely pointed wing, the tip of which lies almost exactly
above posterior end of body of shell. Posterior area much compressed, not sepa-
rated from the flank by a distinct carina, but bordered near the umbo by a broadly
rounded ridge which soon dies out. A median depression of the flank and a corres-
ponding broad sinus of the ventral margin are variably developed. Cardinal area
rather narrow. Posterior area bearing very weak radial riblets, the remainder of the
surface radial threads which are obscure except on the antero-dorsal region ; growth-
rugae present at irregular intervals.

30 JURASSIC BIVALVIA AND GASTROPODA

HOLOTYPE AND PARATYPES. Nos. LL.35086 and LL.35087-88 respectively, three
specimens in all, ex B.P. Coll.

LOCALITY AND HORIZON. Lihimaliao creek, at a point near Mbaru creek, Mand-
awa area, Tanganyika ; Bajocian (?), Pindiro Shales.

REMARKS. The variability is illustrated by the following measurements of the
holotype and of the better preserved paratype. Holotype : length 33-3 mm., height
17-0 mm,, inflation 12:5 mm. Paratype: length 32-5 mm., height 18:2 mm.,
inflation 13-5 mm.

Parallelodon elongatus (J. de C. Sowerby) (1824a: 67, pl. 447, fig. 1), a widespread
European Bajocian species, and P. buckmamni (Richardson) (1843 : 504, text-fig. 243),
Lower Lias of England, are more elongate, less compressed postero-dorsally, and
without the wing-like extension of the hinge-margin.

Genus GRAMMATODON Meek & Hayden 1860
Grammatodon kenyanus sp. noy.
Pl 2; figs. 2@,00) 6, 24, 0

DiaGnosis. Small (length of largest specimen 15 mm.), rectangularly ovate, not
much elongated (height two-thirds of length), well inflated, most so just posterior to
middle of shell. Umbones at about anterior two-fifths of length, broadly rounded
except for a slight median depression, projecting slightly above hinge-margin.
Posterior margin nearly straight, meeting hinge-margin in a fairly well-marked,
slightly obtuse angle. Posterior area somewhat compressed dorsally, not separated
from flank by a carina. Ornament consisting of concentric ribs which become
irregular in later growth-stages ; radial threads, traces of which are seen in places,
may have been present on the whole surface, but, if so, have been largely removed
by erosion in the available specimens.

HOLOTYPE AND PARATYPES. Nos. LL.35006 and LL.35007—09 respectively, four
specimens in all.

LOCALITY AND HORIZON. Didimtu hill, 2 miles S. of Bur Mayo, N.E. Kenya ;
Upper Lias, Toarcian, Didimtu Beds.

Remarks. As the hinge-structure cannot be observed, it is not certain that this
species belongs to Grammatodon rather than to Cucullaea, but it is included in the
former genus on account of its small size. It is less elongate but has a relatively
longer hinge-margin than G. muensterii (Zieten) (1833 : 75, pl. 56, figs. 7a-c), Middle
(?-Upper] Lias of Europe, and also differs in the presence of the concentric ribs.

Grammatodon sublaevigatus (Zieten)
Bl 2, te. 7,

1833. Cucullaea sublaevigata Hartmann [MS.] ; Zieten: 75, pl. 56, figs. 3a~-c.

1837. Arca cucullata Minster [MS.] ; Goldfuss : 148, pl. 123, figs. 7a-c.

1837. Arca concinna (Phillips) ; Goldfuss: 148, pl. 123, figs. 6a, b (non Cucullaea concinna
Phillips).

1952. Grammatodon cf. bathonicus Cox & Arkell ; Ayers : 22.

FROM TANGANYIKA AND KENYA 31

MATERIAL. Two internal moulds (nos. L.83863, L.83869) preserved in pink lime-
stone with numerous other bivalve remains.

LOCALITY AND HORIZON. I mile N. of Asaharbito, N.E. Kenya ; Bathonian
[2 or Callovian], Asaharbito Beds.

ReMARKS. Largely owing to differences in the state of preservation of material
from different formations, specific discrimination among the Bajocian, Bathonian
and Callovian forms of the group of Grammatodon concinnus (Phillips), itself a species
of Oxfordian age, presents some difficulty. Zieten’s Cucullaea sublaevigata was the
first species of this group to be founded on specimens from one of these stages (Bajo-
cian), and, since his figure agrees quite well with the specimens now recorded, parti-
cularly the more elongate one, his specific name is here applied to them. Later
names which seem to be synonymous with it include Cucullaea inflata Roemer (1836 :
105, pl. 6, fig. 22), Avca cucullata Goldfuss 1837, Arca subconcinna d’Orbigny 1850
(= Arca concinna Goldfuss, 1837, pl. 123, figs. 6a, b, non Phillips sp.), Grammatodon
goldfusst Arkell 1930 (based on the same figures of Goldfuss), and possibly G. bathoni-
cus Cox & Arkell 1948 (= Cucullaea concinna Morris & Lycett 1853, pl. 5, fig. 7, non
Phillips sp.).

Subgenus INDOGRAMMATODON Cox 1937

Grammatodon (Indogrammatodon) virgatus (J. de C. Sowerby)
Pl? 2, figs.4,5

1840b. Cucullaea virgata J. de C. Sowerby, pl. 22, figs. 1, 2 and explanation.
1900. Cucullaea lasti Miller : 533, pl. 17, figs. 1, 2.
1940. Gvammatodon (Indogrammatodon) virgatus (J. de C. Sow.) ; Cox : 47, pl. 2, figs. 22-30.

MATERIAL. Several specimens, ex B.P. Coll., those presented to the Museum
bearing the numbers LL.35089—90.

LOCALITIES AND HORIZONS. 4 mile N.W. of bridge over Mkulumuzi river, 2 miles
W. of Tanga, Tanganyika ; Callovian. Lonji creek, W. of Mandawa, Tanganyika ;
Callovian(?). Along Lihimaliao stream at a point about ? mile E. of Njenja, Tangan-
yika ; Upper Oxfordian(?).

REMARKS. These specimens agree, on the one hand, with “ Cucullaea’’ lasti,
originally described from Callovian beds at a locality west of the Mahokondo creek,
N.W. of Kiswere, Tanganyika, and, on the other hand, with specimens of ‘‘ Cucu-
laea”’ virgata from its type-area, Cutch. The number of ribs on the left valve,
omitting a few weak ones, some intercalated between the main ones, others occupying
the posterior area, varies from about 17-24 ; the number on the right valve is con-
siderably larger and at the same time even more variable.

Grammatodon (Indogrammatodon) stockleyi Cox
Bl zyiies@

19374. G. (I.) stockleyi Cox : 197, 200, pl. 16, fig. I.
1960. _ 4G. (J.) stockleyi Cox ; Joubert, pl. 6, figs. 8a, b.

32 JURASSIC BIVALVIA AND GASTROPODA

MATERIAL. The holotype (no. L.54109), described previously, and several para-
types and later collected specimens.

LOCALITIES AND HORIZONS. S. of Tarawanda, 11 miles S.E. of Lugoba, Tangan-
yika ; Callovian. Scarp face, eastern margin of Makoko plain, Bagamoyo hinterland,
Tanganyika ; Oxfordian. Wilderri hill, rr miles S.S.W. of Rahmu, N.E. Kenya ;
Upper Oxfordian, Seir Limestones.

REMARKS. The largest specimens are go mm. long. Among representatives of
Indogrammatodon this species is exceeded in size only by G. (I.) iddurghurensis Cox,
from the Argovian of India. The number of main ribs on the left valve may be as
few as II, but is usually about 15.

Grammatodon (Indogrammatodon) irritans (Hennig)
Pl. 2, fies 3

1914). Cucullaea ivvitans Hennig : 175, pl. 14, fig. 6.
1933. Cucullaea ivvitans Hennig ; Dietrich : 26, pl. 2, figs. 23-32.
1960. Gvammatodon (Indogrammatodon) ivrvitans (Hennig) ; Joubert, pl. 6, fig. 7.

MATERIAL. Numerous specimens.

LOCALITIES AND HORIZONS. Tendaguru neighbourhood (1 mile N.W. of Tendaguru
hill, Kindope, and Kipande path), Tanganyika ; Upper Kimmeridgian, Nerinella
and “‘ Trigonia smeei’’ Beds. Kinjele, 5 miles W. of Mtapaia, N. of Tendaguru,
Tanganyika ; Upper Kimmeridgian, Indogrammatodon Bed. Dussé, 1} miles S.E.
of Rahmu, N.E. Kenya ; Upper Oxfordian, Seir Limestones. Hereri river crossing,
3 miles S. of Melka Kunha, N.E. Kenya ; Kimmeridgian, Hereri Shales.

REMARKS. Compared with G. (J.) virgatus, this species is smaller, less elongate,
more strongly inflated, and more sharply carinate posteriorly, with a more pronounced-
ly concave posterior area. The largest specimens examined are about 35 mm. long.
The number of ribs anterior to the carina on the left valve is usually about 15, but
there may be one or two fewer. In some specimens the number on the right valve
is about the same, but in others it is considerably greater. In some right valves the
ribbing is only feebly developed near the posterior carina.

Grammatodon (Indogrammatodon) matapwaensis sp. nov.
Ply 2; fies. 64;

Di1aGNnosis. Small (length of larger specimen 17 mm.), rectangularly ovate, sub-
equilateral, not much elongated, well inflated, most so anteriorly to mid-length.
Umbo almost median, projecting to a moderate extent above hinge-margin. Poster-
ior area feebly concave, the boundary between it and the flank rounded off, not form-
ing a distinct carina. Flank and area ornamented with well separated, unevenly
spaced radial threads, with densely and regularly arranged concentric threads over-
riding them and occupying their intervals ; the radial threads are slightly the more
closely arranged on the right valve, where one or (rarely) two weaker intercalary

FROM TANGANYIKA AND KENYA 33

threads may occupy the main intervals ; the total number anterior to the carina on
the left valve is uncertain, but must have exceeded 20.

HOLOTYPE AND PARATYPE. Nos. LL.35091, LL.35092 respectively, both ex B.P.
Coll.

LOCALITY AND HORIZON. N. of Matapwa, Pindiro area, Tanganyika ; Upper
Kimmeridgian.

REMARKS. This species is more nearly equilateral than G. (I.) tvritans and has a
blunter boundary between its flank and posterior area and more numerous ribs.
The delicate concentric threads which form part of its ornament have not been
observed in G. (J.) ivritans.

Genus APOLINTER Casey 1961

Apolinter kindopeensis sp. nov.

Pl. 3, figs. 3a, b, 4a, b

Diacnosis. Small, with the length (16 mm. in the larger specimen, the holotype)
slightly less than twice the height ; convexity moderate. Ventral margin evenly
convex, its general direction diverging from the hinge-margin in a posterior direction,
so that the shell is highest near its posterior end. Umbo broadly rounded, placed at
about anterior third of length of shell, protruding slightly above the hinge-margin.
A well-defined umbonal ridge, curved with an upward-facing convexity, runs to the
postero-ventral corner of the shell and delimits a narrow, concave posterior area.
Hinge-margin about three-quarters of length of shell ; postero-dorsal angle obtuse.
It is evident that the ligamental area, although not seen in available specimens, was
narrow, and that the umbones of the two valves were very little separated. Orna-
ment of regular, close-spaced, depressed concentric ribs.

HOLOTYPE AND PARATYPE. Nos. L.56243, L.56244 respectively.

LOCALITY AND HORIZON. Kindope, 2 miles N.N.W. of Tendaguru, Tanganyika.
Upper Kimmeridgian, Nerinella Bed.

REMARKS. The specimens are casts preserved in sandstone and retain traces of
the concentric ornament of the original shell, although not of any radial ornament
that may have been present at its extremities. There is no evidence as to the arrange-
ment of the hinge-teeth. The species is referred to Afolinter on account of its very
close resemblance to the type-species of that genus, Avca aptiensis Pictet & Campiche,
as figured by Woods (1899 : 35, pl. 6, figs. 8, 9). The dentition of Apolinter, figured
by Casey (1961 : 589, fig. 11a) is of the general type characteristic of the genera
Parallelodon and Grammatodon.

No very closely comparable described Jurassic species can be cited. In the
Lower Volgian species “‘ Cucullaea’’ schourovskii Rouillier, referred to Macrodon by

34 JURASSIC BIVALVIA AND GASTROPODA

Borissiak (1905 : 12, pl. 2, figs. 10-14), the ventral margin is usually parallel with
the hinge-margin, although in Borissiak’s “‘ var. a ”’ (fig. 13) there is a slight tendency
for them to diverge posteriorly. In the Callovian species ‘‘ Cucullaea”’ rouilleri
Trautschold, referred to Macrodon by Borissiak (1905 : 8, pl. 2, figs. I-4) and to
Beushausema by Cossmann (1923 : 15, pl. 6, figs. 14-17), the two margins are as
strongly divergent as in the new species, but the shell is more inequilateral and dis-
tinctly irregular in form, some specimens having a broad, shallow sinus of the ventral
margin.

Family CUCULLAEIDAE Stewart 1930
Genus CUCULLAEA Lamarck 1801

Cucullaea kipandeensis sp. nov.
Pl. 3, figs. 1a, b

DiaGnosis. Of medium size, with the length (48-5 mm. in the holotype) well
exceeding the height (38 mm.), strongly inflated, most so anterior to mid-length,
tapering slightly in a posterior direction, with posterior half of ventral margin
flattened or very feebly concave. Umbonal region very broadly rounded and
prominent, the summit just anterior to mid-length. Posterior carina well marked
although rounded off, with a slight sigmoidal curvature, and delimiting a concave
posterior area which is just visible in the side view of the shell. Anterior two-
thirds of flank ornamented with strong, narrow, widely and irregularly spaced radial
ribs, which on its posterior third are replaced by closely spaced, weak riblets crossed
by concentric threads ; posterior area with a few faint radial threads. A few coarse
concentric corrugations mark the later growth-stages of the shell.

HOLOTYPE AND PARATYPES. Holotype, no. L.53146. There are two paratypes,
both ill-preserved.

LocaLITyY AND HORIZON. Kipande, W. of Tendaguru, Tanganyika ; Upper
Kimmeridgian, Nervinella Bed.

REMARKS. The posterior part of the hinge is not clearly exposed and it is un-
certain if the species is correctly included in Cucullaea. It is not so elongate as
typical species of Parallelodon, while its better defined posterior area and its poster-
ior taper distinguish it from /ndogrammatodon. This species recalls a Toarcian shell
figured by Cossmann (1915a : 16, pl. 6, figs. 6-8) under the name Parallelodon guibali,
but its radial ornament is stronger than in Cossmann’s shell and it is less inequi-
lateral. There is also a general similarity to Cucullaea elegans Roemer (1836 : 103,
pl. 6, figs. 16a, b), also from the Upper Lias, and it is to be suspected that Cossmann’s
specimen should have been referred to Roemer’s species. Imperfect specimens from
Tendaguru figured by Dietrich (1933 : 27, pl. 2, figs. 33-35) as a Cucullaea of the
group of C. contracta (Phillips) may have belonged to the present species, but the
radial ribs indicated in that author’s illustrations are indistinct, perhaps owing to the
eroded condition of the specimens.

FROM TANGANYIKA AND KENYA 35

Family ARCIDAE
Genus EONAVICULA Arkell 1929

Eonavicula sp. “ A”
Pi. 2, figs. 8¢,. 0

MATERIAL. One specimen (no. L.g2046).

LocALITY AND HORIZON. Muddo Erri, 12 miles W. of Rahmu, N.E. Kenya ;
Callovian {?—Lower Oxfordian], Muddo Erri Limestones.

DEscRIPTION. This specimen is 31:5 mm. long, well elongated and strongly in-
equilateral, with the umbo at about the anterior quarter of the length. The sym-
metrically arched ventral margin is almost flat in the middle ; the growth-lines show
that it had a shallow median sinus at an earlier stage of growth. The well-marked
posterior carina has a gentle upward-facing concavity and borders a posterior area on
which the internal mould has one conspicuous radial sulcus and traces of at least one
other above it. Although mainly an internal mould, the specimen retains a few
portions of the original shell on which well-marked growth-rugae are crossed by fine
radial threads.

REMARKS. This specimen, which has the general appearance of an Eonavicula
although its hinge-structure is not seen, is more strongly inequilateral than the
Bathonian species E. minuta (J. de C. Sowerby), the best figure of which, published
by Morris & Lycett (1853, pl. 5, fig. 17), is misidentified as Arca aemula. The
Oxfordian (Corallian) species EF. guadrisulcata (J. de C. Sowerby) (Arkell, 19294, pl. 1,
figs. 3-5) is less elongate and inequilateral, and has four sulci on its posterior area.
The Kimmeridgian species FE. fracta (Goldfuss) (1837 : 141, pl. 121, figs. 10a, b) is as
elongate as the present specimen but is not quite so strongly inequilateral, while,
according to Goldfuss’s figure, its posterior area is without sulci. The specimen now
described may thus belong to a new species, but it seems undesirable to assign a name
to it as it retains so little of its shell.

Eonavicula sp. “ B”’
Pi hie

MATERIAL. One specimen (no. LL.11517).

LOCALITY AND HORIZON. Kindope, N.N.W. of Tendaguru, Tanganyika ; Upper
Kimmeridgian, Nerinella Bed.

DESCRIPTION. This specimen, an internal mould, is 22:5 mm. long, well elonga-
ted, and moderately inequilateral, with the umbo at about the anterior third of the
length. The whole of the posterior half of the ventral margin forms a broad sinus.
The well-marked posterior carina has a gentle upward-facing concavity, and above
it are two radial sulci.

REMARKS. This specimen differs from the equally elongate Eonavicula sp. “A”
in the more anterior position of its umbo and in the broad sinus of the posterior part

36 JURASSIC BIVALVIA AND GASTROPODA

of the ventral margin. It is much more elongate than a specimen from Tendaguru
recorded by Dietrich (1933 : 26, pl. 2, fig. 36) as Arca (Eonavicula) cf. quadrisulcata
(Sow.). E. fracta (Goldfuss) (1837 : 141, pl. 121, figs. 10a, b), from the Kimmerid-
gian of Germany, is similarly elongate, but the broad sinus of its ventral margin
occupies a more anterior position.

Superfamily MYTILACEA
Family MYTILIDAE Rafinesque 1815
Genus LITHOPHAGA Roding 1797
Lithophaga suboblonga Dietrich

1933. Lithophaga suboblonga Dietrich : 73, pl. 7, figs. 94, 95.

MATERIAL. Numerous crypts preserved in limestone.

LOCALITIES AND HORIZONS. Kipande creek, Lilomba creek, Tingutitinguti creek,
and N.E. of Nguruwe, all near Tendaguru, Tanganyika ; Upper Kimmeridgian,
“Trigoma smeet’’ Bed. Kindope, 2 miles N.N.W. of Tendaguru, Tanganyika ;
Upper Kimmeridgian, Nevinella Bed.

Genus MODIOLUS Lamarck 1799

Modiolus imbricatus (J. Sowerby)
Pl. 3, figs. 5, 6

1818a. Modiola imbricata J. Sowerby : 21, pl. 212, figs. I, 3.
1935a. Mytilus (Modiolus) imbricatus (J. Sowerby) ; Cox: 162, pl. 16, figs. 3-5.

MATERIAL. About four specimens.

LOCALITIES AND HORIZONS. Lihimaliao creek, at a point near Mbaru creek,
Mandawa area, Tanganyika ; Bajocian (?), Pindiro Shales. Tifo, 14 miles N. of
Wergudud, and Korkai Hammassa, 19 miles E. of Takabba, both N.E. Kenya ;
Oxfordian, Golberobe Beds.

Remarks. Although from two well separated horizons, all the specimens now
recorded seem indistinguishable from the typical M. imbricatus. The range of this
species in Europe is generally accepted as from Bajocian to Callovian, and closely
comparable forms found in the Oxfordian and Kimmeridgian have usually been
identified as M. aequiplicatus (Strombeck) (M. subaequiplicatus (Roemer)). The
view that such forms are specifically inseparable from M. imbricatus was adopted by
me in 1935 when recording specimens from both the Callovian and the Oxfordian of
British Somaliland, and I am still convinced of its correctness.

FROM TANGANYIKA AND KENYA 37

Modiolus anatinus (Smith)
Ping; fie) 7

/ 1817. Modiola anatina Smith: 89.

| 1818a. Modiola cuneata J. Sowerby : 19, pl. 211, fig. 1.

_ 1818a. Modiola gibbosa J. Sowerby : 19, pl. 211, fig. 2.
1818a. Modiola veniformis J. Sowerby : 20, pl. 211, fig. 3.

MATERIAL. About ten specimens.

LOCALITY AND HORIZON. Kidugallo Station and 14 miles to the east, Central
_ Railway, Tanganyika ; Bajocian, Station Beds.

| Remarks. The type-specimens of the above-cited species described by J.
_ Sowerby, which are in the British Museum (Natural History), are all from the Fuller’s
_ Earth (Bathonian), although Sowerby wrongly stated that those of M/. cuneata and
_M. reniformis were from the Inferior Oolite. They all belong to the same species,
which Smith (1817) had described as M. anatina. In Europe it is wide-
_ spread in the Bajocian and Bathonian and has been recorded from the Callovian.

This species differs from M. imbricatus in its greater inflation, its shorter form and
_ more distinctly cuneiform outline, and shorter and more bulging antero-ventral lobe,
' which is separated from the flank by a furrow which tends to become accentuated
_ when specimens, like those now recorded, have been partly flattened by pressure.

Modiolus bipartitus (J. Sowerby)
Pir 3, fs. 9

1818a. Modiola bipartita J. Sowerby : 17, pl. 210, figs. 3, 4.
| 1929a. Modiola bipartita J. Sowerby ; Arkell: 55, pl. 2, figs. 1-4.
1948. Modiolus bipartitus J. Sowerby ; Cox & Arkell; 4.

MATERIAL. Two specimens (nos. L.52087, LL.35093), the latter ex B.P. Coll.

LOCALITIES AND HORIZONS. 4} mile N.W. of bridge over Mkulumuzi river, 2 miles
W. of Tanga, Tanganyika ; Callovian. Tingutitinguti creek, Tendaguru, Tangan-
_yika ; Upper Kimmeridgian, “ Tvigonia smeer”’ Bed.

REMARKS. These specimens have a shorter hinge-margin, a less pronounced
postero-dorsal angle, and a more convex antero-ventral lobe than those referred to
_M. imbricatus. They are smaller than the holotype of M. bipartitus and the other
_ English specimens figured by Arkell, but agree with them in shape. The affinities of
| a specimen from Tendaguru recorded by Dietrich (1933 : 72, pl. 2, fig. 42) as ““ Modto-
lasp., Gruppe der M. bipartita’”’ are less certain. The range of the species in England
is Upper Bathonian (Lower Cornbrash) to Kimmeridgian, but it is rare above the
Oxfordian.

38 JURASSIC BIVALVIA AND GASTROPODA

Modiolus virgulinus (Thurmann & Etallon)
P58, He’

1862. Mytilus virgulinus Thurmann & Etallon : 224, pl. 29, fig. 6.
1875. Mytilus virgulinus Etallon ; de Loriol : 152, pl. 18, figs. 17, 18.
1960. Modiolus virgulinus (Etallon) ; Joubert, pl. 6, figs. 12a, b.

MATERIAL. One specimen (no. L.g2181).

LOCALITY AND HORIZON. 3 miles N.E. of Melka Dakacha, N.E. Kenya ; Upper
Kimmeridgian, Dakacha Limestones.

REMARKS. This specimen agrees very closely in shape with de Loriol’s fig. 18,
cited above. It is, however, rather eroded near the dorsal margin and so does not
show the strong growth-rugae which are confined to this region in typical specimens
of the species. M. virgulinus, as its name suggests, occurs in France in the “ Virgu-
lian ’’ stage of the Kimmeridgian.

Subgenus INOPERNA Conrad 1875

Modiolus (Inoperna) sowerbianus (d’Orbigny)
Pl. 3), figs, 10,07

1819a. Modiola plicata J. Sowerby : 87, pl. 248, fig. 1 (non Mytilus plicatus Gmelin 1791).
1850a. Mutylus |sic| sowerbianus d’Orbigny : 282.

1910. Modiola plicata Sow. ; Dacqué : 30, pl. 5, fig. to.

1940. Modiolus (Inoperna) plicatus J. Sowerby ; Cox: 71, pl. 5, figs. 13, 14.

MATERIAL. Two fragments from the Toarcian ; several specimens from higher
beds.

LOCALITIES AND HORIZONS. Didimtu hill, 2 miles S. of Bur Mayo, N.E. Kenya ;
Upper Lias, Toarcian, Didimtu Beds. Korkai Hammassa, 19 miles E. of Takabba,
N.E. Kenya, and Tifo, 14 miles N. of Wergudud, N.E. Kenya ; Oxfordian, Golberobe
Beds.

Remarks. In this species each of the strong oblique ribs which meet the dorsal
margin of the shell splits up half-way to the diagonal carina into from three to
several weak ribs, or is replaced by them without distinctly splitting up. This
feature of the ribbing is observable in the Toarcian specimens now recorded and in
the best preserved one from higher beds.

D’Orbigny’s replacement name is here adopted for the species in consequence of
the Article 59(b) of the International Code, whereby secondary homonymy pro-
duced prior to 1961 (in this case by d’Orbigny’s transference of Sowerby’s species to
Mytilus) requires a permanent change of the specific name.

FROM TANGANYIKA AND KENYA 39

Modiolus (Inoperna) perplicatus (Etallon)
Pl. 3;-fig. 14

1862. Mytilus perplicatus Etallon, in Thurmann & Etallon : 223, pl. 29, fig. 8.
1913. Modiola (Pharomytilus) perplicata (Etallon) ; Dietrich : 73.

1914b. Modiola perplicata (Etallon) ; Hennig: 176, pl. 14, fig. 4.

1960. Modiolus (Inoperna) perplicatus (Etallon) ; Joubert, pl. 6, figs. 13a, b.

MATERIAL. Six specimens.

LOCALITIES AND HORIZONS. 3 miles N.E. of Melka Dakacha, N.E. Kenya ;
Upper Kimmeridgian, Dakacha Limestones. Tendaguru, Tanganyika ; Upper
Kimmeridgian. Kinjele, 5 miles W. of Mtapaia, N. of Tendaguru, Tanganyika ;
Upper Kimmeridgian, [ndogrammatodon Bed.

RemARKS. This species differs from M. (I.) sowerbianus in that each of the oblique
ribs meeting the dorsal margin bifurcates half-way to the diagonal carina and is thus
replaced by exactly two weaker ribs. In Europe this form occurs only in the
Kimmeridgian.

Genus MUSCULUS Roding 1797
Musculus kindopeensis sp. nov.
Pl. 4; figs. za, 6

DiaGnosis. Small (length of holotype 9:3 mm.), moderately elongate, with the
length, measured parallel to the hinge-margin, rather less than twice the height, not
greatly oblique, ornamented, as in typical Musculus, with radial threads which are
absent from the concave area separating the antero-ventral lobe from the most
inflated part of the shell, which runs diagonally from the beak to the postero-ventral

corner. The threads of the posterior series number about 36 where they meet the
margin; those of the anterior series about 12.

HOLOTYPE AND PARATYPES. Holotype, no. LL.11331. Six paratypes, nos.
Pa50284, LL.11328—30, LL.11332, LL.11516.

LOCALITY AND HORIZON. Scarp at Kindope, 2 miles N.N.W. of Tendaguru,
Tanganyika ; Upper Kimmeridgian, Nerinella Bed.

REMARKS. This form is less elongate and smaller than the European Kimmerid-
gian-Portlandian species M. autissiodorensis (Cotteau) (de Loriol 1868 : 625, pl. 12,
fie. 8 ; 1875 : 152, pl. 18, fig. 14).

Genus MYTILUS Linnaeus 1758
Subgenus FALCIMYTILUS Cox 1937
Mytilus (Falcimytilus) tifoensis sp. nov.
Fl. 3; figs. 52, 13
1957. Lycettia dalpiazt Venzo ; Saggerson & Miller: 14.

Dracnosis. Of medium size (diagonal measurement from beak to postero-
ventral corner 39 mm. in the holotype), markedly falciform, oblique (the diagonal

40 JURASSIC BIVALVIA AND GASTROPODA

forming an angle of about 45° with the hinge-margin), variable in breadth, moderate-
ly inflated ; dorsal margin not much elongated, meeting the convex posterior margin
in a broad curve. A very sharp ridge, strongly curved and forming almost a quad-
rant, runs from the beak to the ventral extremity and separates the flank from a
narrow antero-ventral region which slopes steeply to the margin and protrudes
beyond the ridge, so as to be visible in the side-view of the shell only near the beak.
Surface ornament unknown, the specimens being internal moulds.

HOLOTYPE AND PARATYPES. Holotype, no L.g3615. Three paratypes, nos.
L.93581, L.93616-17.

LOCALITIES AND HORIZON. Tifo, 14 miles N. of Wergudud, and Ogar Wein hills,
17 miles N.W. of Wergudud, N.E. Kenya ; Oxfordian, Golberobe Beds.

REMARKS. The specimens upon which this species is founded were originally
recorded (Saggerson & Miller 1957 : 14) as Lycettia dalpiazt Venzo. On careful
examination, however, they prove to belong to a species of Falcimytilus in which the
diagonal ridge is unusually sharp, as they differ from Lycettia in the distinct protru-
sion of the anterior margin beyond the ridge. Mytilus (Falcimytilus) suprajurensis
Cox (1925 : 142, pl. 1, fig. 9 ; pl. 3, fig. 2°; 1937¢ : 344, pl. 17, figs. 1-3), from the
Kimmeridgian and Portlandian of England, is a closely related but rather larger
species.

Mytilus (Falcimytilus) jurensis Roemer

1836. Mytilus jurensis [ex Merian MS.] Roemer : 89, pl. 4, fig. 10.
1935a. Mytilus jurensis Roemer ; Cox: 161, pl. 15, figs. 15-17.

MATERIAL. Six specimens.

LOCALITIES AND HORIZONS. Romicho, 25 miles S.W. of El Wak, N.E. Kenya ;
beds just underlying Golberobe Beds (Oxfordian). 23 miles S.W. of Rahmu, N.E.
Kenya ; Oxfordian, Rahmu Shales. Dussé, 13 miles S.E. of Rahmu, N.E. Kenya ;
Upper Oxfordian, Seir Limestones. Hereri river crossing, 3 miles S. of Melka
Kunha, N.E. Kenya ; Kimmeridgian, Hereri Shales.

ReMARKS. Like those from Somaliland figured in the work cited (Cox 19354),
these specimens vary considerably in obliquity and in the development of an antero-
ventral bulge, which gives some of them a modioliform outline.

Mytilus (Falcimytilus) dietrichi sp. nov.
Pl.°3) figs. 35, 16

1914b. Mytilus cf. galliennei d’Orbigny ; Hennig: 157, pl. 14, figs. 3a, b.
1933. Mytilus sp. ; Dietrich: 72.

Diacnosis. Of medium size (diagonal measurement from beak to postero-ventral
corner 33 mm. in holotype), oblique (the diagonal forming an angle of about 45°
with the hinge-margin), variable in breadth, moderately inflated ; dorsal margin not
much elongated, meeting the convex posterior margin in a broad curve. A blunt

FROM TANGANYIKA AND KENYA 41

and scarcely curved ridge runs from the beak to the ventral margin and separates the
flank from a narrow antero-ventral region, the margin of which presents only a slight
concavity below the beak and does not project anteriorly to it. Surface unornamen-
ted.

HOLOTYPE AND PARATYPES. Holotype, no. L.52187 ; numerous paratypes.

LOCALITIES AND HORIZONS. Dirahara, 24 miles E.N.E. of Aus Mandula, N.E.
Kenya, and Tifo, 14 miles N. of Wergudud, N.E. Kenya ; Oxfordian, Golberobe
Beds. Tendaguru neighbourhood (Kindope valley, Tingutitinguti creek, Lilomba
creek), and Kinjele, 5 miles W. of Mtapaia, N. of Tendaguru, Tanganyika ; all
Upper Kimmeridgian, “ Tvigonia smeei’’ Bed.

REMARKS. Mytilus galliennei d’Orbigny, the Cenomanian species from France
to which this form was originally compared by Hennig, has a less marked diagonal
ridge, lacks any convexity of the anterior margin below the beak, and has weak
transverse striations on its antero-ventral region.

Genus BRACHIDONTES Swainson 1840
Subgenus ARCOMYTILUS Agassiz 1842

Brachidontes (Arcomytilus) asper (J. Sowerby)
Pl. 4, figs. 2a, b
1818a. Modiola aspera J. Sowerby : 22, pl. 212, fig. 4.

1948. Bvrachidontes (Acromytilus) asper (J. Sowerby) ; Cox & Arkell: 5.
1960. Bvrachidontes (Arcomytilus) asper (J. Sowerby) ; Joubert, pl. 6, figs. 1oa—c.

MATERIAL. Two specimens (nos. L.g2067, L.g2177).

LOCALITIES AND HORIZONS. 2 miles W. of Melka Biini, N.E. Kenya ; Bathonian,
Murri Limestones. Kulong, 2 miles S.W. of Muddo Erri, N.E. Kenya ; Callovian
[?-Lower Oxfordian], Muddo Erri Limestones.

REMARKS. The specimens now recorded are typical examples of this species,
which in England appears to be restricted to the Bathonian, but is known from the
Callovian of various other areas.

Brachidontes (Arcomytilus) laitmairensis (de Loriol)
Blo 4 fies. 3

1883. Mytilus laitmaivensis de Loriol: 57, pl. 8, figs. 6-12.
1935a. Mytilus (Arcomytilus) laitmaivensis de Loriol ; Cox : 164, pl. 15, figs. 13, 14.
1960. Mytilus (Arcomytilus) sp. ; Joubert, pl. 6, fig. 9.

MATERIAL. Four specimens.

LOCALITIES AND HORIzONS. Kulong, 2 miles S.W. of Muddo Erri, N.E. Kenya ;
Callovian [?-Lower Oxfordian], Muddo Erri Limestones. Tifo, 14 miles N. of
Wergudud, N.E. Kenya ; Oxfordian, Golberobe Beds. N. of Matapwa, Pindiro
area, Tanganyika ; Upper Kimmeridgian.

42 JURASSIC BIVALVIA AND GASTROPODA

REMARKS. The differences between this species and B. (A.) subpectinatus (d’Or-
bigny) (= pectinatus (J. Sowerby)) were discussed by me in the work cited above.
The specimens now recorded, including those from the Kimmeridgian, agree with
B. (A.) laitmairensts in their rounded postero-ventral margin and in the absence of a
definite ridge running from the umbo to the posterior end of this margin. This
species occurs most commonly in the Callovian, but Arkell has recorded its occurrence
in the English Oxfordian. It has not been recorded previously from the Kimmerid-
gian. The true B. (A.) subpectinatus has been recorded from Tendaguru by Dietrich
(1933 : 72, pl. 2, fig. 47), but is not represented in the collections from that locality
in the British Museum (Natural History).

Superfamily PTERIACEA
Family PTERIIDAE Gray 1847
Genus PTERIA Scopoli 1777
Pteria tanganyicensis sp. nov.
Pl. 4, fig. 4

Diacnosis. Large (original length at least 9 cm.), well inflated, obliquely elon-
gate, with a rather narrow body which has a slight sigmoidal curvature. Anterior
wing large, acute, not compressed ; posterior wing more compressed and differentia-
ted from the body than the anterior one, appearing (from its earlier growth lines) to
have had an acutely pointed tip (it is broken away distally in the holotype). Sur-
face of shell without radial ornament.

Ho.totyrPe. No. LL.16793, aright valve damaged posteriorly. The only specimen.

LOCALITY AND HORIZON. Usigiwa river, 6 miles W.S.W. of Kiwangwa, Baga-
moyo hinterland, Tanganyika ; Upper Oxfordian,

REMARKS. The cardinal area is not seen in the holotype, so that the number of
ligamental pits cannot be ascertained, but the species is referred to Pteria as its
general form is more suggestive of that genus than of any representatives of the family
Bakevelliidae. In size and shape it much resembles Avicula struckmanni de Loriol
(1875 : 164, pl. 20, fig. 1), from the Kimmeridgian of France, but it differs in the
much larger size of its anterior auricle. No comparable form has been recorded
previously from East Africa.

Family BAKEVELLIIDAE King 1850
Genus BAKEVELLIA King 1848
Bakevellia iraonensis (Newton)
1895. Gervillia ivaonensis Newton : 80, pl. 2, figs. 8, 9.

MATERIAL. [our specimens (nos. LL.7224—27).
LOCALITY AND HORIZON. Quarries N.N.E. of Ngerengere, Central Railway,
Tanganyika ; Bajocian (?).

PROM TANGANYIKA AND KENYA 43

Remarks. Although ill-preserved, these specimens can be seen to have the strong
inflation and the general outline of Newton’s species, the holotype of which, from
the Bathonian of Madagascar, is in the British Museum (Natural History). Hennig
(1914a : 65 ; 1924 : 31) has already recorded the presence of a form identified as
Gervillia aff. 1vaonensis in Tanganyika.

Genus GERVILLELLA Waagen 1907

Gervillella didimtuensis sp. nov.
Pl. 4, figs. 5a, 5, 6

Diacnosis. Of medium size (measuring up to 50 mm. from anterior end of
hinge-line to extremity of body), moderately inflated, trapezoidal, oblique ; shell-
wall very thick. Anterior and ventral margins forming a strongly convex, uninter-
rupted curve. Body of shell broad, evenly inflated, its level descending gradually
to the anterior margin and to the posterior wing. Length of hinge-margin about
four-fifths of that of shell ; posterior wing obtusely angular, apparently not acutely
pointed at its tip in any stage of growth. Anterior auricle absent ; beak terminal
in most specimens, but in some the anterior margin projects very slightly beyond it.
Umbo projecting only very slightly above hinge-margin. Ligamental pits four or
fewer, extending from beak along about two-thirds of hinge-margin. A rather long,
oblique, ridge-like tooth, inclined at an angle of about 45° with the hinge-margin,
originates just below the beak ; posterior to it are several small, similarly oblique
teeth, and near the posterior end of the hinge-margin and diverging only slightly
from it is a strong, elongate tooth.

HOLOTYPE AND PARATYPES. Nos. LL.35012 and LL.35013-16 respectively, five
specimens in all.

LOCALITY AND HORIZON. Didimtu hill, 2 miles S. of Bur Mayo, N.E. Kenya ;
Upper Lias, Toarcian, Didimtu Beds.

REMARKS. The absence of an anterior auricle readily distinguishes this species
from the Bajocian form, Gervillella orientalis, described next.

Gervillella orientalis (Douvillé)
Pl. 4, figs. 7a, b, 8

1916. Gervillia orientalis Douvillé : 59, pl. 4, figs. 14-17.

MATERIAL. Several specimens ; ex B.P. Coll.

LOCALITIES AND HORIZON. Lihimaliao creek, at a point near Mbaru creek,
Mandawa area, Tanganyika ; near site of Mandawa well no. 1, Tanganyika ; depth
50-52 feet in Mandawa well no. 6, Tanganyika ; all Bajocian (?), Pindiro Shales.

DEscRIPTION. The shell is of medium size (measuring up to 40 mm. from tip of
anterior auricle to extremity of body), subequivalve, oblique. The length of the

44 JURASSIC BIVALVIA AND GASTROPODA

hinge-margin is about three-fifths of that of the shell. When not broken away, an
acute anterior auricle extends well beyond the umbo, which projects only slightly
above the hinge-margin. The anterior and ventral margins form a strongly convex,
uninterrupted curve. The body of the shell, which varies considerably in breadth
and obliquity, is evenly and moderately inflated, its level descending gradually to the
anterior margin and to the posterior wing. The growth-lines show that the posterior
wing, which is obtusely triangular in general shape, was acutely pointed at its
extremity in earlier growth-stages. In the material examined some shell fragments
show traces of hinge-teeth, but the complete dentition is not displayed.

REMARKS. This species was based on several broken specimens from Jebel
Aroussieh, Sinai. Douvillé queried their age as Callovian, but a specimen collected
more recently is from beds which are undoubtedly Bathonian in age. Douvillé’s
figures indicate a range of variation similar to that shown by the specimens now
described, and justify the inclusion of all of these in the same species. The present
specimens, however, lack the radial sulcus of the body of the shell observable in
specimens from Sinai. The less expanded specimens of the species rather resemble
Gervillella ovata (Morris & Lycett), an English Bathonian form, differing mainly in
the presence of the pointed anterior auricle. G. ivaonensis (Newton), Bathonian of
Madagascar, is a more gibbose shell with a broad sinus of the anterior margin.

Gervillella siliqua (Eudes-Deslongchamps)
Pl A, fig. 10

1824. Gervillia siliqua Eudes-Deslongchamps : 128, pl. 4.
1940. Gervillella siliqua (Eudes-Deslongchamps) ; Cox : 112, pl. 7, figs. 12-14.

MATERIAL. One specimen (no. L.92032).

LOCALITY AND HORIZON. Tifo, 14 miles N. of Wergudud, N.E. Kenya ; Oxfordian,
Golberobe Beds.

REMARKS. The specimen now recorded, which is about 45 mm. long, closely
resembles one from the Oxfordian of Cutch, India, represented in fig. 13 of the work
cited above. To the synonyms of G. siliqgua there given should probably be added
Gervillia mayert Moesch (1867 : 308, pl. 5, figs. 10a, b).

Gervillella aviculoides (J. Sowerby)

1814a. Peyna aviculoides J. Sowerby : 147, pl. 66, figs. 1-4.

1836. Gervillia tetvragona Roemer : 85, pl. 4, fig. 11.

1875. Gervillia tetvragona Roemer ; de Loriol: 165, pl. 19, figs. 3-5.
1933a. Gevvillia aviculoides (J. Sowerby) ; Arkell : 203, pl. 26, figs. 1-5.
1933. Gevvilleia (Gevvillella) sp., aviculoides-Gruppe ; Dietrich : 60.

MATERIAL. Several imperfect specimens.

LOCALITIES AND HORIZONS. I mile N.W. of Tendaguru hill and scarp at Kindope,
N.N.W. of Tendaguru, Tanganyika ; Upper Kimmeridgian, Nerinella Bed. Tin-

FROM TANGANYIKA AND KENYA 45

gutitinguti creek, Tendaguru ; Upper Kimmeridgian, “ Tvigonia smeei’’ Bed.
Just W. of Mabokweni, 4 miles N.W. of Tanga, Tanganyika ; Kimmeridgian.

REMARKS. De Loriol and other authors have applied Roemer’s name Gervillia
tetragona to a species which occurs in the Kimmeridgian of France and other Euro-
pean countries. Comparison of French specimens of that age with typical English
specimens of G. aviculoides, from the Corallian Beds (Oxfordian), has convinced me
that all belong to the same species. The East African specimens now recorded
cannot be distinguished from the European species.

Genus GERVILLIA Defrance 1820

Gervillia saggersoni sp. nov.
Pl. 4, fie. 15

SPECIFIC NAME. After Dr. E. P. Saggerson, of the Kenya Geological Survey.

Diacnosis. Of medium size (length of holotype 62-5 mm.), broadly falciform,
not greatly oblique, diagonal from umbo forming an angle of about 15° with hinge-
margin. Hinge-margin about one-half of length of shell ; umbo protruding only
slightly and situated near anterior end of hinge-margin. Anterior and ventral
margins forming an uninterrupted, strongly convex curve ; posterior extremity
bluntly rounded. Body of shell, which attains a maximum width of about 17 mm.
in the holotype, evenly convex ; posterior wing narrow, flattened but not well
differentiated, with an obtuse outer angle.

Hototyre. No. L.93622, consisting of internal and external moulds of a left
valve. A second internal mould (no. L.g3499) is too ill-preserved to rank as a para-
type.

LOCALITIES AND HORIZON. Korkai Hammassa, 19 miles E. of Takabba, N.E.
Kenya (type-locality), and Ogar Wein, 17 miles N.W. of Wergudud, N.E. Kenya ;
Oxfordian, Golberobe Beds.

Remarks. This form was originally recorded (Saggerson & Miller 1957 : 14) as
Gervillia cf. monotis Eudes—Deslongchamps, but the true G. monotis, from the Bathon-
ian of Europe, is a smaller form with a narrower body. The most closely comparable
species is Gervillia pancict Radovanovié (1900 : 64, pl. 1, figs. 4, 5), from the Lower
Lias of Yugoslavia, but this appears to have a longer dorsal margin. In view of
their falciform outline these forms seem better included in Gervillia than in Gervillella.

Family PINNIDAE
Genus PINNA Linnaeus 1758
Pinna buchii Koch & Dunker

Pl. 4, fig. 9

1837. Pinna buchii Koch & Dunker : 33, pl. 2, fig. 18.
1869. Pinna buch K. & D.; Brauns: 230.
1899. Pinna buchi K. & D.; Greppin : 99, pl. 13, figs. 5, 6.

40 JURASSIC BIVALVIA AND GASTROPODA

MATERIAL. One specimen (no. LL.35095).

LOCALITY AND HORIZON. Near site of Mandawa well no. 1, Tanganyika ; Bajo-
cian (?), Pindiro Shales.

REMARKS. The specimen is a crushed right valve with a sub-median carina on the
dorsal side of which are about 12 radial riblets ; the ventral side bears well-marked
growth-folds but is devoid of radial ornament. In having its radial ornament con-
fined to the dorsal half of the surface the specimen resembles the original figure of the
species, which represents a specimen from the Inferior Oolite of Holtensen, northern
Germany ; its riblets, however, are more numerous than in the German specimen.
In the specimens from the Upper Bajocian of Switzerland figured by Greppin radial
riblets are present also on the ventral side of the median carina.

Pinna mitis Phillips

1829. Pinna mitis Phillips : 137, pl. 5, fig. 7.

1883. Pinna mitis Phil. ; Lahusen: 27, pl. 2, fig. 12.
1910. Pinnasp. ; Dacqué: 29, pl. 5, fig. 4.

1924. Pinna nutis Ziet. ; Hennig: 71, pl. 2, fig. 7.
1934. Pinna mitis Phil. ; Stoll: 109, pl. 2, fig. 9.

MATERIAL. Several specimens.

LOCALITY AND HORIZON. 6} miles N.E. of Pande (village on Mkwaja—Mkata road)
and 2} miles N. of Msangasi stream, N.E. Tanganyika ; Callovian.

REMARKS. The specimens, the largest of which were about 60 mm. long when
complete, are preserved in a hard sandstone and, when an attempt is made to extract
them, usually break in such a manner that part of the wall of the shell adheres to
each counterpart. Sufficient of their ornament can, however, be seen to show that
it agrees with that of Pinna mitis, already recognized by Hennig (1924) in the Callo-
vian of Tanganyika.

Pinna constantini de Loriol

1875. Pinna constantini de Loriol : 161, pl. 19, fig. 2.
1897. Pinna constantim de Loriol ; Futterer : 596, pl. 20, figs. 5, 5a.
1933. Pinna cf. constantini de Loriol ; Dietrich : 60, pl. 8, figs. 131-134.

MATERIAL. Several specimens.

LOCALITIES AND HORIZONS. Valley and scarp at Kindope, N.N.W. of Tendaguru,
Tanganyika ; Upper Kimmeridgian, “ 7vigonia smeei”’ and Nerinella Beds.

REMARKS. The specimens from East Africa agree so well with de Loriol’s illustra-
tion of the type specimen from the “ Portlandien moyen ”’ of France, that there
seems no need to qualify the identification. The number of ribs on the dorsal side
of the median carina of each valve is 5—7, while the number below the carina in-
creases during growth to 6 or more, the extreme ventral part of the surface bearing
only growth-folds.

FROM TANGANYIKA AND KENYA 47

There is some doubt whether this form should be considered synonymous with
Pinna ornata d’Orbigny, a French Kimmeridgian species, one of the syntypes of
which has been figured by Cottreau (1932, pl. 66, fig. 15). The ribs below the median
carina seem to be weaker in P. ornata, but the difference is not great and only
relatively small specimens have so far been figured.

Genus STEGOCONCHA Bohm 1907

Stegoconcha gmuelleri (Krenkel)
Pl. 5, fig. 8

1910. Pinna G. Miilleri Krenkel : 203, pl. 21, fig. 5.
1933. Stegoconcha solida Bohm var. tendagurensis Dietrich : 61, pl. 9, figs. 138, 139.

MATERIAL. Several specimens.

LOCALITIES AND HORIZONS. I mile N.W. of Tendaguru hill, Tanganyika, around
Kipande, W. of Tendaguru, and Kindope, N.N.W. of Tendaguru ; all Upper
Kimmeridgian, Nerinedla Bed. Dussé, 1} miles S.E. of Rahmu, N.E. Kenya ;
Upper Oxfordian, Seir Limestones.

Family MALLEIDAE Gray 1823
Genus ELIGMUS Eudes-Deslongchamps 1856

Eligmus rollandi Douvillé
Pl. 5, figs. 5, 6

1907a. Heligmus rollandi Douvillé : 105, pl. 15, figs. 1-3.
1929. Heligmus rollandi Douvillé ; Weir: 23, pl. 1, figs. 24-28.
1935a. Eligmus rollandi Douvillé ; Cox : 168, pl. 16, figs. 6-10.
1960. Eligmus rvollandi Douvillé ; Joubert, pl. 8, fig. 11.

MATERIAL. Several specimens.
LOCALITIES AND HORIZON. Muddo Erri ; Kulong, 2 miles S.W. of Muddo Erri ;
Muddo river bed 4 miles S.W. of Muddo Erri ; S. of Rahmu—Melka Murri road, 6 miles

W. of Rahmu ; 14 miles W.S.W. of Rahmu ; all N.E. Kenya : Callovian [?-Lower
Oxfordian], Muddo Erri Limestones.

Superfamily PECTINACEA
Family OXYTOMIDAE Ichikawa 1958
Genus OXYTOMA Meek 1864
Oxytoma inequivalvis (J. Sowerby)
Plessiiee7
1819a. Avicula inequivalvis J. Sowerby : 78, pl. 244, figs. 2, 3.

1933. Oxytoma inaequivalvis var. hennigi Dietrich : 58, pl. 7, figs. 99-101.
1940. Oxytoma inequivalve (J. Sowerby) ; Cox : 98, pl. 6, figs. 9-12.

48 JURASSIC BIVALVIA AND GASTROPODA

MATERIAL. Two specimens.

LOCALITIES AND HORIZONS. Chinamba, ? mile S. of Amboni quarries, Tanga,
Tanganyika ; Callovian (?) (ex B.P. Coll.). Kindope valley, N.N.W. of Tendaguru,
Tanganyika ; Upper Kimmeridgian, Nevinella Bed.

Genus MELEAGRINELLA Whitfield 1885
Meleagrinella echinata (Smith)

1817. Avicula echinata Smith : 67.
1940. Echinotis echinata (Smith) ; Cox : 92, pl. 6, figs. 2-7.
1948. Meleagrinella echinata (Smith) ; Cox & Arkell: 7.

MATERIAL. Two specimens.

LOCALITY AND HORIZON. S. of Tarawanda, 11 miles S.E. of Lugoba, Tanganyika ;
Callovian.

REMARKS. The specimens now recorded are not well preserved, but the number
of their ribs is the same as in typical specimens of M. echinata and considerably fewer
than in the specimens recorded below as M. radiata ; the ribs, moreover, are more
equal in strength than in M. radiata. Miller and Hennig have reported M. echinata
from the “ Dogger ’”’ of Tanganyika.

Meleagrinella radiata (Trautschold)
Pl..5, figs. 14, 6:24, 0934, 0, 4a,°0

1860. Aucella vadiata Trautschold : 343, pl. 6, figs. 7, 8.

1870. Avicula (Monotis) tenuicostata Greppin : 350, pl. 5, figs. 7a, b (non Avicula tenuicostata
Roemer 1841).

1899. Pseudomonotis tenuicostata (Greppin) ; de Loriol : 169, pl. ro, fig. 36.

1900. Pseudomonotis tenuicostata (Greppin) ; de Loriol : 126, pl. 6, fig. 44.

1900. Avicula heberti Miller : 542, pl. 19, figs. 14-17.

1910. Avicula tschingiva Krenkel : 203, pl. 20, fig. 12.

1912. Pseudomonotis radiata (Trautschold) ; Sokolov : 108, pl. 2, figs. 11-13.

1914. Pseudomonotis loyioli Rollier : 312 (for P. tenwicostata de Loriol non Greppin sp.).

1914). Pseudomonotis tendagurensis Hennig: 182.

1924. Pseudomonotis epechinata Hennig : 87.

1933. Pseudomonotis tendagurensis Hennig ; Dietrich : 57, pl. 8, figs. 107-117.

1938. Pseudomonotis lieberti (Miller) ; Weir : 45, pl. 3, fig. 5.

MATERIAL. Numerous specimens.

LOCALITIES AND HORIZONS. Korkai Hammassa, 19 miles E. of Takabba, Ogar
Wein, 17 miles N.W. of Wergudud, and Chimpa, all N.E. Kenya ; Oxfordian,
Golberobe Beds. Plantations N. of Dakatcha village, and also 3 mile E. of Merikano,
both in Malindi district, Coast Province, Kenya ; in loose boulders, respectively of
hard sandstone and of limestone, of uncertain age. Usigiwa river, 6 miles W.S.W.
of Kiwangwa, Bagamoyo hinterland, Tanganyika ; Upper Oxfordian. Kiwate-
Mkange track, 5 miles S.S.E. of Mkange, Bagamoyo hinterland, Tanganyika ;

FROM TANGANYIKA AND KENYA 49

Oxfordian or Kimmeridgian. 17 miles S. of Rahmu, N.E. Kenya ; Upper Oxford-
ian, Seir Limestones. Several localities around Tendaguru, Tanganyika ; Upper
Kimmeridgian, “‘ Tvigonia smeei’’ and Nerinella Beds. Kinjele, 5 miles W. of
Mtapaia, N. of Tendaguru, Tanganyika ; Upper Kimmeridgian, Indogrammatodon
Bed.

REMARKS. Hennig and Dietrich did not adopt Miller’s specific name /ieberti, the
first to be applied to East African specimens of this species, when recording speci-
mens from Tendaguru, because Miiller’s description and figures suggested that he
was dealing with a form in which the shell was completely smooth. The material
from this locality now studied, however, includes specimens which appear smooth
either because their outer shell layer has disappeared or because they are merely
internal moulds. It thus seems evident that Miiller’s types were specimens pre-
served in one of these ways. Hennig apparently overlooked Krenkel’s description
of Avicula tschingiva when founding his species Pseudomonotis tendagurensis.

In specimens from the Tendaguru district the left valve is ornamented with
numerous closely arranged, narrow, round-topped riblets of unequal strength,
increasing by intercalation. Details vary considerably in different shells. On parts
of the surface in many specimens the riblets alternate in strength or weaker ones
alternate with pairs of stronger ones. On some specimens the stronger ribs bear
obscure, evenly spaced, imbricating scales. Right valves are of feeble convexity
and bear well separated radial riblets. It has seemed important to reach a decision
as to the identity of the Meleagrinella which is the most abundant species found in
the Golberobe Beds of northern Kenya, and has been figured by Saggerson & Miller
(1957 : 19, figs. b-d). Iam now convinced that it is not possible to draw any specific
distinction between this form and the Tendaguru species, as specimens with closely
similar ornament occur in both areas. Those now illustrated include one (figs. 3a,))
with particularly numerous and closely spaced ribs. In the Golberobe specimens
the right valve is almost smooth, with faint radial ribbing appearing in its later
growth-stages. The largest of these specimens are about 15 mm. long.

It is also necessary to discuss whether previous workers have been justified in
asssuming that the Tendaguru species is distinct from any found in Europe. In M.
echinata, a European form recorded above from Tanganyika, the left valve is more
strongly inflated and the ribs are less numerous, stronger, and more uniform in
strength. In M. braamburiensis (Phillips), which occurs in the European Callovian
and Oxfordian and has been well figured by Douglas & Arkell (1932 : 163, pl. 12,
figs. 5, 6), the ornament is very similar to that of the Tendaguru form, but specimens
commonly attain a length of 25-30 mm., which much exceeds the usual size of the
latter. The species described by Trautschold as Aucella radiata and discussed in
1912 by Sokolov (who has included Avicula tenuicostata Greppin in its synonymy)
appears, however, to be indistinguishable from the East African form, as inspection
of de Loriol’s figures of A. tenwicostata willshow. In Europe M. radiata occurs in the
Lower Oxfordian, so that its recognition in the Golberobe Beds of Kenya is in keep-
ing with the supposed Oxfordian age of these beds. In view of its occurrence at

50 JURASSIC BIVALVIA AND GASTROPODA

Tendaguru also, it is clear that in East Africa it has a moderately extended geological
range.

Family POSIDONIIDAE
Genus BOSITRA de Gregorio 1886

Bositra buchii (Roemer)
Pleo fig er.

1836. Posidonia Buchii Roemer : 81, pl. 4, fig. 8.

1851. Posidonia orvnati Quenstedt : 517, pl. 42, fig. 16.

1852. Posidonomya alpina Gras: 11, 48, pl. 1, fig. 1.

1869. Posidonomya Buchii (Roemer) ; Brauns : 242.

1896. Posidonomya Buchi (Roemer) ; Stremoouchow : 391, pl. 10.
1924. Posidonomya Buchii (Roemer) ; Hennig: 43.

1928. Posidonomya alpina Gras ; Guillaume : 228, pl. ro, figs. 4-13.
1930. Posidonia orvnati Quenstedt ; Weir : 83, pl. ro, figs. 14-21.
1938. Posidonia ornati Quenstedt ; Weir: 45, pl. 3, fig. 5.

1940. Posidonia ornati Quenstedt ; Cox : 103, pl. 7, figs. 10, 11.

MATERIAL. Numerous specimens.

LOCALITIES AND HORIZONS. Kidugallo Station, Central Railway, Tanganyika ;
Bajocian, Station Beds. Boreholes 5 miles N. of Kidugallo and at Lugoba, Tangan-
yika ; Lower Bajocian (Aalenian) (see Arkell, 1956 : 330). About 23 miles S.S.W. of
Tengeni (village on Pangani river), N.E. Tanganyika ; horizon uncertain. Kaya
Kauma, 8 miles W. of Kilifi, Kenya ; Upper Callovian, Miritini Shales.

REMARKS. Many authorities have recognized that Posidonia buchi was founded
on an unusually elongate specimen of the species more commonly known as P. ornati
Quenstedt or as P. alpina (Gras), and this view is here accepted, although in previous
works I have used Quenstedt’s name for the species. It has an exceptionally long
geological range, extending from the Toarcian (in Argentina) to the Upper Callovian.
The recent work of R. P. S. Jefferies has shown that there are good grounds for the
generic separation of P. buchii and related Jurassic forms from the type-species of
Posidonia, P. becheri Bronn of the Carboniferous, and the generic name Bositra has
long been available for them.

Bositra somaliensis (Cox)
PI..6, fig, 2

1935a. Posidonia somaliensis Cox : 166, pl. 15, figs. 7, 8.

MATERIAL. One specimen (no. L.51207).

LOCALITY AND HORIZON. Kindope valley, N.N.W. of Tendaguru, Tanganyika ;
Upper Kimmeridgian, Nerinella Bed.

REMARKS. This valve of a Bositra, which is about 20-5 mm. long and slightly less
in height, seems referable to B. somaliensis in view of its size and known geological
age. B. bononiensis (de Loriol) (1875 : 170, pl. 21, figs. 3-5), from the Kimmeridgian
of France, is a much smaller form.

FROM TANGANYIKA AND KENYA 51

Family AMUSIIDAE Ridewood 1903
Genus ENTOLIUM Meek 1865
Entolium corneolum (Young & Bird)

1828. Pecten corneolus Young & Bird : 234, pl. 9, fig. 5.

1900. Pecten demissus Phillips ; Miiller : 527, pl. 17, fig. ro.

1924. Pecten demissus Phillips ; Hennig: 14, pl. 2, figs. 1, 2.

1929. Entolium solidum (Roemer) ; Weir : 23, pl. 1, fig. 33.

1930a. Entoliwm demissum (Phillips) ; Arkell: 91, pl. 7, fig. 4; pl. 9, fig. 8.
1930. Entolium demissum (Phillips) ; Weir: 87, pl. 10, figs. 4, 9.

1933. Pecten (Entolium) solidus Roemer ; Dietrich : 65, pl. 8, figs. 118, 119.
1938. LEntolium demissum (Phillips) ; Weir: 46, pl. 3, fig. 8.

1948. Entolium corneolum (Young & Bird) ; Cox & Arkell: 15.

MATERIAL. Several specimens.

LOCALITIES AND HORIZONS. Kulong, 2 miles S.W. of Muddo Erri, N.E. Kenya ;
Callovian {?-Lower Oxfordian], Muddo Erri Limestones. Wilderri hill, rz miles
.S.S.W. of Rahmu, N.E. Kenya ; Upper Oxfordian, Seir Limestones. Manyuli
stream, just W. of Nautope, Mandawa—Mahokondo anticline, Tanganyika ; Callo-
-vian. Scarp face, E. margin of Makoko plain, Bagamoyo hinterland, Tanganyika ;
Upper Oxfordian. Hillside overlooking Lake Mbuo, Pindiro area, Tanganyika ;
Middle Kimmeridgian. Valley and scarp at Kindope, N.N.W. of Tendaguru, Tang-
| anyika ; Upper Kimmeridgian, Nerinella and “‘ Trigonia smeet’’ Beds. Kinjele, 5
miles W. of Mtapaia, N. of Tendaguru, Tanganyika ; Upper Kimmeridgian,
Indogrammatodon Bed.

_ Remarks. Authors who have drawn a specific distinction between Pecten solidus

Roemer and P. demissus Phillips have admitted that stratigraphical rather than
morphological considerations have led them to do so. Mlle C. Dechaseaux (1936 :
| 61) has regarded them as synonymous. Arkell has shown that Pecten corneolus was
_the earliest name for the species commonly known as Entoliwm demissum.

Entolium briconense (Cossmann)
PY 6ztig. 6

1907. Chlamys (Syncyclonema) briconensis Cossmann : 108, pl. 3, figs. 14, 15.
1913a. Chlamys (Syncyclonema) briconensis Cossmann ; Cossmann : 3, pl. I, fig. 20.
/1917. Chlamys (Syncyclonema) briconensis Cossmann ; Couffon : 120, pl. 4, fig. 1.
1924. Syncyclonema briconense Cossmann ; Cossmann : 30, pl. 5, figs. 1, 2.

MATERIAL. Three imperfect specimens (two in B.P. Coll.).
_ LOCALITIES AND HORIZONS. Plantation 43 miles N. of Dakatcha village, Coast
Province, Kenya ; in loose boulder. 24 miles N. of Msaka road junction, Baga-
moyo district, Tanganyika ; Callovian.

REMARKS. The specimens referred to this species, which was previously known
only from the Callovian of France, have a characteristic ornament of concentric lines
arranged in pairs a constant distance apart. They agree particularly well with the

52 JURASSIC BIVALVIA AND GASTROPODA

shell figured by Cossmann (1913@), who considers each pair of lines to mark the bases
of attachment of concentric lamellae which formed the ornament of the uneroded
shell.

Entolium cingulatum (Goldfuss)

Pl. 6, fig. 5

1836. Pecten cingulatus Goldfuss : 74 (partim), pl. 99, figs. 3a, b(?).
1926. Entolium cingulatum (Goldfuss) ; Staesche : 93, pl. 4, figs. 3, 4.

MATERIAL. One valve (counterparts), no. LL.35202.

LOCALITY AND HORIZON. 5 miles N.E. of Tengeni (village on Pangani river), at
S. end of divide separating western tributary from main Maweni valley ; Upper
Jurassic.

REMARKS. This specimen, a valve about 30 mm. high, clearly shows the two
internal laminae, diverging from the beak and forming very acute angles with the
dorsal margins of the body of the shell, which are characteristic of this and certain
related species. There has been some difference of opinion as to the exact species to
which Goldfuss’s name cingulatus should be applied. In his original description
Goldfuss attributed the species to Phillips and gave a reference to a figure published
by that author (1829, pl. 5, fig. 11), representing a specimen from the Oxford Clay of
England. Phillips, however, had merely recorded his specimen as Pecten sp. and for
that reason it had been given the name Pecten phillips by Thurmann (1833 : 32).
Thus Goldfuss, not Phillips, was the author of the name cingulatus, and when describ-
ing the species he recorded it from localities belonging partly to the Lias and partly
to the White Jura, without stating from which his figured specimens came. D’Orbigny
(1850a : 238, 257) assigned the names Pecten philenor and P. proeteus to species found
at different horizons of the Lias, in each case referring to Goldfuss’s figures of P.
cingulatus. Staesche has maintained that this action amounted to the restriction of
Goldfuss’s species to specimens from the White Jura, a doubtful conclusion, particu-
larly in view of the fact that d’Orbigny did not adopt the name cingulatus for speci-
mens from any horizon. The matter could be finally resolved only by the definite
selection of one of Goldfuss’s figured specimens as lectotype of P. cingulatus, if the
specimens can be traced and their horizons are determinable. The name cingulatus
is, however, now adopted in the sense advocated by Staesche, according to whom
the species to which it is applied ranges throughout the White Jura in Germany.
The Oxford Clay specimen figured by Phillips, holotype of Pecten phillipsti Thurmann,
belonged to a species which is certainly distinct although not readily identified.

Family PECTINIDAE Rafinesque 1815
Genus EOPECTEN Douvillé 1897

Eopecten aubryi (Douvillé)
Pl. 6, figs. 3, 4

1886. Pleuronectites aubryi Douvillé : 228, pl. 12, fig. 3.
1929. Velata inaequistriata (Futterer) ; Weir: 25, pl. 1, fig 24 only. (non Futterer sp.).

FROM TANGANYIKA AND KENYA 53

1939. Velata aubryi (Douv.) ; Stefanini : 186, pl. 20, figs. 10, 11 ; pl. 21, fig. 1.
1952. LEopecten aubryi (Douv.) ; Cox : 31, pl. 3, figs. 8-10.

1960. LEopecten aubryi (Douv.) ; Joubert, pl. 8, figs. 1a, b.

1960. Eopecten abjectus (Phillips) ; Joubert, pl. 7, fig. 7 (non Phillips sp.).

MATERIAL. Several specimens, one ex B.P. Coll.

LOCALITIES AND HORIZONS. 34 miles W. of Melka Biini, N.E. Kenya ; Callovian,
Rukesa Shales. Muddo Erri, 12 miles W. of Rahmu, N.E. Kenya, Kulong, 2 miles
to the S.W., and S. of Rahmu—Melka Murri road, 6 miles W. of Rahmu ; all Callovian
[?-Lower Oxfordian], Muddo Erri Limestones. Manyuli stream, just W. of Nautope,
Mandawa—Mahokondo anticline, Tanganyika ; Callovian. Mandawa—Lonji creek
traverse, Mandawa area, Tanganyika ; Upper Oxfordian.

REMARKS. Specimens from N.E. Kenya are mostly quite typical of this species,
as described in the works cited above, although the one figured under the name E.
abjectus by Joubert (1960) has very unevenly spaced ribs. Those from the Upper
Oxfordian of Tanganyika, while agreeing with the typical E. aubryi in the number,
equality, and fairly regular distribution of the main radial ribs, differ in the almost
complete smoothness of the intervals, which bear at the most a faint median riblet,
finer interstitial threads being absent. There are insufficient grounds at present for
distinguishing them even as a new sub-species, although they seem to be of rather
later age than the hitherto recorded range (Bathonian—Lower Oxfordian) of E.
aubryt. There are three specimens of the right valve of this species in the material
studied, and their ornament consists of numerous fine, subequal, weakly granose

radial riblets.

Eopecten thurmanni (Brauns)
Pl. 6, fig. 8

| 1850b. Hinnites inaequistriatus d’Orbigny : 22 (ex Voltz MS. ; a secondary homonym of: Lima
inaequistriata Goldfuss, 1836, also an Eopecten).

1862. Himnnites inaequistriatus d’Orb. ; Thurmann & Etallon : 267, pl. 37, fig. 13.

| 1863. Hinnites inaequistriatus d’Orb. ; Dollfus : 26, pl. 16, figs. 1-3.

| 1872. Hinnites inaequistriatus (Voltz) ; de Loriol : 391, pl. 23, figs. 1, 2.

1874. Hinnites thurmanni Brauns : 343.

|1881. Hinnites inaequistriatus (Voltz) ; Boehm: 181, pl. 40, fig. 1.

1881. Hinnites gigas Boehm : 182, pl. 40, figs. 11, 12.

|1897. Hinnites (Pleuronectites) inaequistriatus (Voltz) ; Futterer : 588, pl. 19, figs. 6, 7.

1915. Huinnites (Prospondylus) orbignyi Rollier : 464.

1915. Hinnites (Prospondylus) dollfusi Rollier : 465.

1933. Velata inaequistriata (Voltz) ; Dietrich : 67, pl. 8, fig. 129.

1936. Velata inaequistriata (Etal.) ; Dechaseaux : 71.

MATERIAL. Two left valves (nos. L.83900, L.g2195).

LOCALITIES AND HORIZONS. 7 miles N.N.E. of Raiya hills, N.E. Kenya ; Upper
_Oxfordian, Seir Limestones. Hereri river crossing, 3 miles S. of Melka Kunha, N.E.
Kenya ; Kimmeridgian, Hereri Shales.

REMARKS. One of these two specimens is remarkable for its size, its diameter

54 JURASSIC BIVALVIA AND GASTROPODA

being about 90 mm. It is a well-inflated valve, ornamented with a relatively small
number (about 8) of rather unevenly spaced, prominent ribs, separated by wide
intervals occupied by numerous radial threads which alternate in strength more or
less regularly ; there is a slight tendency for the middle thread of each main interval
to be more prominent than the others. This specimen seems to be larger than any
hitherto recorded under the specific name imnaequistriata, but it is smaller than
Boehm’s Hinnites gigas, a shell 155 mm. high. Notwithstanding the very irregular
arrangement of its ribs, it is now suggested that Boehm’s species should be considered
a synonym of the imaequistriata of authors. The necessity for adopting Braun’s
name thurmanni for this species is indicated by the synonymy here given. The
European range of this species is from the Upper Oxfordian to the Kimmeridgian.

Eopecten aff. albus (Quenstedt)
Pl, 6sfige7

1836. aft. Spondylus velatus Goldfuss : 94, pl. 105, figs. 4a—-d (secondary homonym of Pecten
velatus Goldfuss, 1833 : 45, also an Eopecten).

1857. aff. Pecten velatus albus Quenstedt : 628, pl. 78, fig. 3.

1878. aff. Hinnites astartinus Greppin ; de Loriol : 163, pl. 23, fig. 3.

1904. aff. Hinnites bonjouri de Loriol : 231, pl. 25, figs. I, 2.

1926. aff. Velopecten velatus (Goldfuss) ; Staesche : 122, pl. 6, fig. 11.

1936. aff. Velata bonjouri (de Loriol) ; Dechaseaux : 70, pl. 8, fig. 14.

1960. Eopecten cf. bonjouri (de Loriol) ; Joubert, pl. 8, fig. 2.

MATERIAL. One specimen (no. L.g2247).

LOCALITY AND HORIZON. Wilderri hill, 11 miles S.S.W. of Rahmu, N.E. Kenya ;
Upper Oxfordian, Seir Limestones.

REMARKS. This specimen, a strongly convex left valve of an Eopecten, is only
about 22 mm. high and not identifiable specifically with any certainty. There are
about 13 rather irregularly spaced, weak, narrow principal radial costae which are
separated by flat intervals ; a weak thread of secondary strength is present in one
or two of these, but otherwise they appear smooth. It is probable that a few more
ribs of primary strength would have appeared as the shell grew. The specimen
bears some resemblance to de Loriol’s fig. 2 of Hinnites bonjouri, a species considered
by Staesche to be a synonym of the form to which he applies the name V elopecten
velatus, a secondary homonym. The name albus Quenstedt is here accepted for the
species. In Germany, according to Staesche, this ranges throughout the Malm, or
Upper Jurassic.

Genus CAMPTONECTES Meek 1864

Camptonectes auritus (Schlotheim)

1813. Chamuites auritus Schlotheim : 103.

1929. Chlamys (Camptonectes) lens (Sowerby) ; Weir: 25, pl. 1, fig. 39.
1930a. Camptonectes lens (Sowerby) ; Arkell : 94, pl. 7, fig. 1 ; pl. 9, figs. 4-7.
1948. Camptonectes auritus (Schlotheim) ; Cox & Arkell: 14.

1960. Camptonectes aurites {sic} (Schlotheim) ; Joubert, pl. 7, figs. 3a-e.

FROM TANGANYIKA AND KENYA 55

MATERIAL. Several specimens.

LOCALITIES AND HORIZONS. Kulong, 2 miles S.W. of Muddo Ermi, also top of
hills S. of Rahmu—Melka Murri road, 10 miles W. of Rahmu, N.E. Kenya ; Callovian
[?-Lower Oxfordian], Muddo Erri Limestones. 2} miles S.W. of Rahmu, N.E.
Kenya ; Oxfordian, Rahmu Shales. Dussé, 13 miles S.E. of Rahmu; Upper Oxford-
ian, Seir Limestones.

Genus CHLAMYS Roding 1708
Chlamys curvivarians (Dietrich)

1929. Chlamys aff. palmyrensis (Krumbeck) ; Weir : 24, pl. 1, figs. 34, 35.
1929. Chlamys sp. ; Weir: 25, pl. 1, fig. 38.

1933. Pecten (Chlamys) curvivarians Dietrich : 63, pl. 8, figs. 122, 123.
1935a. Chlamys curvivarians (Dietrich) ; Cox: 176, pl. 18, figs. 14, 15.
1939. Chlamys curvivarians (Dietrich) ; Stefanini: 183, pl. 20, fig. 9.
1952. Chlamys curvivarians (Dietrich) ; Cox : 8, pl. 2, figs. 5, 8.

1960. Chlamys curvivarians (Dietrich) ; Joubert, pl. 7, fig. 5.

MATERIAL. Several specimens.

LOCALITIES AND HORIZONS. 2 miles S. of Melka Biini, N.E. Kenya ; Bathonian,
Murri Limestones. 34 miles W. of Melka Biini ; Callovian, Rukesa Shales. Ku-
long, 2 miles S.W. of Muddo Erri ; also top of hills S. of Rahmu—Melka Murri road,
to miles W. of Rahmu, N.E. Kenya ; Callovian [?-Lower Oxfordian], Muddo Erri
Limestones. Hereri river crossing, 3 miles S. of Melka Kunha, N.E. Kenya ; Kim-
meridgian, Hereri Shales. Finno, Hegalu hills, N.E. Kenya ; Upper Kimmeridgian,
Dakacha Limestones.

Remarks. This species has been fully discussed in the papers cited. Its long

range in East Africa is indicated by the occurrences stated above.

Chlamys subtextoria (Minster)
Pl..7, fig. 8

1833. Pecten subtextorius Miinster in Goldfuss : 48, pl. 90, figs. 114, b.

1857. Pecten textorius albus Quenstedt : 627, pl. 77, figs. 25, 26.

1894. Pecten bipartitus Futterer : 32, pl. 5, figs. 4, 4a.

1926. Chlamys subtextoria (Minster) ; Staesche : 40 (partim) (non pl. 1, fig. 4).
1936. Chlamys subtextorius (Goldfuss) ; Dechaseaux : 109, pl. 3, fig: 2.

1936. ?Chlamys Etiveyensis (de Loriol) ; Dechaseaux, pl. 3, figs. 3, 4.

MATERIAL. One specimen (no. L.54116).

LOCALITY AND HORIZON. S. of Tarawanda, 11 miles S.E. of Lugoba, Tanganyika ;
Callovian.

DEscriPTIon. This specimen, a right valve about 22 mm. high, is characterized
by its rather tall, trigonal outline, its slightly acute umbonal angle, and the relatively
elongate dorsal margins of the disc. Its narrow, acutely angular costae, about 33
in number, are distributed a little irregularly, with no pronounced tendency to be

56 JURASSIC BIVALVIA AND GASTROPODA

arranged in pairs. On the least eroded parts of the surface the ribs and their inter-
vals are seen to be crossed by concentric lamellae. The upper margin of the anterior
auricle slopes upward from the umbo. Growth stages of the inner margin of the
subauricular notch are marked by a series of lamellae.

REMARKS. Staesche has placed Pecten etiveyensis de Loriol (1904, pl. 24, fig. 1)
in the synonymy of C. subtextoria, but Mlle Dechaseaux has regarded the two forms
as distinct, stating that etiveyensis differs in the regularity, equality, and rounded
(rather than angular) cross-section of its numerous ribs, points of distinction also
emphasized by de Loriol when describing the species. By these criteria, Staesche’s
figured specimen of “ subtextoria’’ would be referable to etiveyensis. Mlle De-
chaseaux’s figures (pl. 3, figs. 3, 4) of specimens referred to etiveyensis rather contra-
dict this distinction, however, as they indicate a decidedly irregular arrangement of
the costae, which also appear to have broader intervals than in the typical etiveyensis.
In its tall, trigonal form and acute umbonal angle the East African specimen now
recorded more closely resembles the specimens which Mlle Dechaseaux figures as
etiveyensis than the one attributed to subtextoria, although the obtusely angular ribs
are like those of the last specimen. It is possible that Staesche’s broader conception
of the species subtextoria is justified. The references given in the above synonymy
are, however, to illustrations of specimens in which the ribbing is less regular and the
intervals are broader than in the typical etiveyensis. Pecten bipartitus Futterer (1894:
32, pl. 5, figs. 4, 4a), from Oxfordian beds at Mkusi, 16 miles N.E. of Mtaru, Tangan-
yika, does not seem to differ from C. subtextoria ; whereas it was described as having
18—20 ribs, 30 can be counted in the figure.

Chlamys matapwaensis sp. nov.
Pl. 7, figs. 1a, b, 2a, b

Di1AGNosIs. Small, subequivalve, of slight convexity, inequilateral, height (c. 11
mm. in larger specimen) just exceeding length (10 mm.). Valves ornamented with
22 or rather more slightly unevenly spaced, rounded, smooth riblets of moderate
prominence, the outer ones curving outwards towards the adjacent margin ; the
riblets may increase in number to a small extent during growth by dichotomy or by
intercalation, the latter occurring mainly at a late growth-stage and only in some of
the outer intervals. Intervals flat, their average width about the same as that of the
riblets, ornamented with very fine concentric threads. Right posterior auricle
obtusely triangular ; other auricles unknown complete ; byssal sinus unknown ;
part of right anterior auricle closest to body of shell bearing series of closely spaced,
equal threads perpendicular to the hinge-margin.

HOLOTYPE AND PARATYPE. Nos. LL.35096, LL.35097 respectively (ex B.P. Coll.).

LOCALITY AND HORIZON. N. of Matapwa, Pindiro area, Tanganyika ; Upper
Kimmeridgian.

REMARKS. In Chlamys curvivarians (Dietrich), recorded above, the riblets are
narrower and more numerous.

FROM TANGANYIKA AND KENYA 57

Subgenus RADULOPECTEN Rollier 1911
Chlamys (Radulopecten) inequicostata (Young & Bird)
Pl. 7, fig. 5

1822. Pecten inequicostatus Young & Bird : 236, pl. 9, fig. 7.
1829. Pecten inaequicostatus Phillips : 129, pl. 4, fig. ro.
1931a. Chlamys (Radulopecten) inaequicostata (Phillips) ; Arkell: 118, pl. 8, figs. 4-7 (also

1935, pl. 52, figs. 1, 3).
1960. Chlamys (Radulopecten) cf. inaequistriata (Phillips) ; Joubert, pl. 7, fig. 4.

MATERIAL. One specimen (no. L.g2228).

LOCALITY AND HORIZON. Dussé, 1} miles S.E. of Rahmu, N.E. Kenya ; Upper
Oxfordian, Seir Limestones.

DeEscrIPTION. This specimen, which lacks the umbonal region and auricles and
is rather eroded, was originally about 67 mm. high and 50 mm. long. The right
valve has about six broad, depressed, rounded ribs which are separated by equally
broad intervals ; ribs and intervals are crossed by fine, closely spaced, rather
irregular, erect lamellae. The left valve has six ribs which are narrower than those
of the right valve and are separated by intervals most of which are slightly broader
than the ribs. One of the outer ribs on the anterior side bears short, spine-like
projections, but details of the ornament are not preserved on the others.

REMARKS. The African specimen differs from most examples of the species from
the Corallian Beds of England, the type occurrence, in the relative broadness of the
intervals between the costae of the right valve, but in occasional specimens from
England the intervals are just as broad. I see no reason, therefore, for separating
the African specimen from C. imaequicostata, which is also known from France,
Germany, Poland, and Switzerland. In Europe the species occurs in the Upper
Oxfordian and Lower Kimmeridgian.

Chlamys (Radulopecten ?) kinjeleensis sp. nov.
Pl. 7, figs. 6a, b, 7a, b

DiaGnosis. Shell small (height of holotype, the largest specimen, c. 13 mm.),
suborbicular, subequivalve, moderately convex. Ornament consisting of about 10
regularly arranged, broad, rounded radial costae, separated by slightly narrower,
rounded intervals ; ribs and intervals crossed by concentric threads (removed by
erosion except on a few small areas of the surface in the available specimens). Right
anterior auricle small, bearing two weak radial riblets ; posterior auricles rather
small, obtusely triangular. Byssal notch deep.

HOLOTYPE AND PARATYPES. Holotype, no. L.51955, a right valve. Three para-
types (including nos. L.52145 and LL.35008, ex B.P. Coll.).

LOCALITIES AND HORIZONS. N. of Kinjele, 5 miles W. of Mtapaia, N. of Tenda-
guru, Tanganyika (type-locality) ; Upper Kimmeridgian, Nerinella Bed. Lilomba

58 JURASSIC BIVALVIA AND GASTROPODA

creek, Tendaguru, Tanganyika ; Upper Kimmeridgian, “ Trigomia smeet’’ Bed.
Mpilepile stream bed, near Mitole, and Kiwawa stream, both northern Mandawa
area, Tanganyika ; Upper Kimmeridgian.

REMARKS. This species appears to be closely related to Chlamys (Radulopecten)
inaequicostata, recorded above, but is much smaller and has more ribs. The speci-
mens, although from four different localities, are all of about the same size, so that
it has been assumed that they are full-grown.

Subgenus SPONDYLOPECTEN Roeder 1882
Chlamys (Spondylopecten ?) badiensis Cox

Pi 7; figs: 33.4
1952. Chlamys (Spondylopecten ?) badiensis Cox : 16, pl. 1, figs. 14a, b.

MATERIAL. Two specimens (nos. L.g3552, LL.35099), the latter ex B.P. Coll.

LOCALITIES AND HORIZON. Namakambe stream, Mandawa—Mahokondo anticline,
Tanganyika ; probably Callovian. 4 mile N.W. of bridge over Mkulumuzi river,
2 miles W. of Tanga, Tanganyika ; Callovian.

DESCRIPTION. Both specimens have 23 rounded, moderately prominent ribs, as
in the holotype of C. badiensis. In one specimen the dorsal margins of the body of
the shell are concave and extend almost to the middle of the height of the valve,
the ventral margin of which forms a semicircle. In the second specimen the dorsal
margins are relatively short, extending only to the dorsal third of the height of the
valve, and the ventral margin is semi-elliptical. Although the two specimens thus
differ considerably in outline, it is thought that they belong to the same species. In
the first and less eroded specimen, a right valve 28 mm. high, the ribs bear a median
and two lateral rows of small scales, together with regular, delicate transverse
striations which are arched towards the umbo. The narrow, V-shaped intervals
are also transversely striated and are bordered on each side by a longitudinal thread
at the base of the adjacent rib. The second specimen, a left valve of about the same
height, retains traces of similar ornament in places. The auricles are imperfect in
both specimens, but can be seen to bear squamose or beaded radial riblets.

REMARKS. C. badiensis, the holotype of which came from the Callovian of Cutch,
is closely related to the French Callovian species C. palinurus (d’Orbigny) (see
Cossmann, 1913a : 2, pl. 11, figs. I-4 ; 1924 : 29, pl. 5, figs. 5, 6), but in that species
the number of ribs is only 20. Other related forms are C. syviaca Cossmann (1925 :
325, pl. 8, figs. 7a—-c), with about 30 ribs, and C. macfadyent Cox (19354 : 176, pl. 18,
figs. 1a, b), with 19 ribs. All possibly could be geographical races of C. palinurus.
The ligamental area of the right valve has not been observed in any of these forms,
but their tentative reference to Spondylopecten is suggested by their external simi-
larity to Pecten erinaceus Buvignier, its type species.

FROM TANGANYIKA AND KENYA 59

Genus WEYLA Boehm 1920

Weyla ambongoensis (Thevenin)
PI..7; figs..9@,.b, c

1908b. Pecten ambongoensis Thevenin : 24, pl. 4, figs. 2, 3.
1948. Pecten ambongoensis Thev. ; Dubar: 220, pl. 29, figs. 7-9.

MATERIAL. Numerous specimens.

LOCALITY AND HORIZON. Didimtu hill, 2 miles S. of Bur Mayo, N.E. Kenya ;
Upper Lias, Toarcian, Didimtu Beds.

REMARKS. The specimens now recorded are quite typical of this species, which
is known from the Upper Lias of Pakistan and Morocco as well as from the type-
locality in Madagascar.

Superfamily LIMACEA
Family LIMIDAE Rafinesque 1815
Genus LIMA Cuvier 1798
Subgenus PLAGIOSTOMA J. Sowerby 1814
Lima (Plagiostoma) biiniensis sp. nov.
Ph. 8; figs x

1929. Cf. Lima (Plagiostoma) cf. rigida Sow. ; Weir: 27, pl. 2, fig. 2.
1960. Lima (Plagiostoma) sp. nov. ; Joubert, pl. 8, fig. 4.

Diacnosis. Of medium size (height of holotype c. 53 mm.), suborbicular,
slightly higher than long ; inflation even and moderate. Ventral margin strongly
convex and not pronouncedly asymmetrical ; umbonal region obtusely angular in
outline, its angle about 100° ; anterior umbonal ridge rounded off, relatively short.
Main part of surface bearing numerous (probably about 70) radial riblets which
project very little, are flat-topped in the holotype, and are separated by much
narrower intervals which are seen to be punctate where the shell is least eroded.
Auricles not preserved.

HoLotyPe. No. L.g2174. A few other specimens in the material studied may
belong to the same species but are all imperfect and cannot rank as paratypes.

LOCALITIES AND HORIZONS. 2 miles W. of Melka Biini, N.E. Kenya ; Bathonian,
Murri Limestones. Possible representatives of the species from Kulong, 2 miles
S.W. of Muddo Erri, N.E. Kenya ; Callovian [?-Lower Oxfordian], Muddo Erri
Limestones.

REMARKS. The ornament of this species much resembles that of the Bajocian
species L. semicircularis Goldfuss, discussed by the present writer (Cox 1943 : 160,
pl. 10, figs. 13, 14). The new species differs, however, in its more even inflation, its
shorter and less marked anterior umbonal ridge, and its fewer radial ribs (their
number is 80—90 in L. semicircularis). There are many records of L. semicircularis

60 JURASSIC BIVALVIA AND GASTROPODA

from the Bathonian, but not one where the recorded specimens are illustrated can be
accepted. The specimen figured under this name by Morris & Lycett (1853, pl. 3,
fig. 3) has been made the type of a new species L. bynet by Cox & Arkell (1948 : 17)
and has fewer ribs than the form now described. Weir (1938, pl. 4, fig. 16) has
figured a specimen from the Kambe Limestone (Upper Bajocian or Bathonian) of
Kenya as L. cf. semicircularis. Its ribbing has been largely removed by erosion, but
its outline resembles that of the species now described.

Lima (Plagiostoma) cf. schardti de Loriol

1883. Cf. Lima schardti de Loriol : 71, pl. ro, figs. 5-11.
1960. Lima (Plagiostoma) cf. schardti de Loriol ; Joubert, pl. 8, fig. 3.

MATERIAL. Several imperfect specimens.

LOCALITIES AND HORIZONS. Hills S. of Melka Murri-Rahmu road, 13 miles W. of
Rahmu, N.E. Kenya ; Callovian, Rukesa Shales. Kulong, 2 miles S.W. of Muddo
Erri, N.E. Kenya ; Callovian [?-Lower Oxfordian], Muddo Erri Limestones.

RemARKs. In this species, originally described from the Mytilus Beds (Bathonian—
Callovian) of Switzerland, the valves bear about 26 scaly ribs separated by intervals
which are of the same width as the ribs over the greater part of the surface but become
wider than them near the ventral margin. The ribs cannot be counted exactly in the
specimens now recorded but their spacing is exactly as indicated in de Loriol’s figures
and their scaly character can be seen in places. The general outline of the shell is
also as indicated by de Loriol.

Lima (Plagiostoma) muddoensis sp. nov.
Pl 8ptigs2

1960. Lima (Plagiostoma) cf. complanata Laube ; Joubert, pl. 8, fig. 5.

Diacnosis. Of small-medium size (height of holotype c. 35 mm.), trapezoidal,
length and height almost equal ; inflation rather weak in holotype, but this is
probably partly due to compression in fossilization. Ventral margin moderately
asymmetrical ; umbonal region not protruding, very slightly obtuse in outline, its
angle about 100° ; anterior umbonal ridge rounded off, straight, forming an angle
with the hinge-line which slightly exceeds 45°. Lunule scarcely excavated. Poste-
rior auricle relatively large, its outer angle only slightly obtuse ; anterior auricle not
seen. Main surface bearing about 30 prominent, rounded ribs which are equal in
strength and appear smooth except in late stages of growth, when they bear trans-
verse imbrications. Intervals about same width as ribs and apparently without
punctations. Posterior auricle with about 6 nodose radial ribs.

Hototyre. No. L.g2065 ; the material examined includes about two other
specimens which probably belong to the same species but are too imperfect to rank
as paratypes.

FROM TANGANYIKA AND KENYA 61

LOCALITY AND HORIZON. Muddo Erri, N.E. Kenya ; Callovian [?-Lower Oxford-
ian], Muddo Erri Limestones.

Remarks. This Lima, although rather similar to several previously described
species, cannot be identified definitely with any of them. L. complanata Laube
(1867 : 24, pl. 1, fig. rr), Callovian of Poland, has a narrower body and umbonal
region, a smaller posterior auricle, and more ribs. In L. paoli Stefanini (1939 : 164,
pl. 19, figs. 7, 8), from the “‘ Lower Oolitic’ of Somaliland, there are 36-38 ribs
which are much more depressed than in the new species and have narrower intervals.
In L. subcardiiformis Greppin, a widespread Bathonian species, the ribs are much
more numerous. Of the varied series of Limidae occurring in the Bajocian of England,
L. bradfordensis Cox (1943 : 159, pl. 9, fig. 10) is quite closely similar to the present
species, but its ribs are relatively broader and their intervals narrower. L. notata
Goldfuss (1836 : 83, pl. 102, figs. 1a, b), of the Upper Oxfordian and Kimmeridgian,
is more equilateral in outline.

“e

Lima (Plagiostoma) cf. jumaraensis Cox

1952. Cf. Lima (Plagiostoma) jumaraensis Cox : 52, pl. 5, figs. 4a, b, 5.

MATERIAL. About four ill-preserved specimens.

LOCALITY AND HORIZON. Kulong, 2 miles S.W. of Muddo Erri, N.E. Kenya ;
Callovian {?-Lower Oxfordian], Muddo Erri Limestones.

Remarks. In this species, originally described from the Bathonian and Callovian
of India, the narrow ribs are very depressed, projecting only slightly between the
radiating linear grooves which separate them. In the specimens now recorded the
ornament agrees well with that of the Indian ones, but not one is well enough pre-
served to show the complete outline of the shell. The specimens from Somaliland
recorded by Stefanini (1939 : 162, pl. 19, figs. 5a, b, 6a, b) as Lima (Plagiostoma)
strigillata Laube are very similar to those now described, some of which were pro-
visionally identified (Joubert 1960 : 18) as Laube’s species after comparison with
Stefanini’s figures.

Lima (Plagiostoma) rahmuensis sp. nov.
Pl,7, figs. roa, b

Diacnosis. Of medium size (height of holotype c. 35 mm.), trapezoidal, slightly
higher than long, well inflated. Ventral margin moderately asymmetrical ; um-
bonal region obtusely angular in outline, its angle about 120° ; anterior umbonal
ridge rounded off, straight, not greatly elongated, forming an angle of about 45°
with the hinge-margin ; lunule well excavated. Main part of surface bearing
numerous punctate linear radial grooves, about 7 of which occcupy a width of 5 mm.
near the ventral margin ; spaces between grooves quite flat.

HototyPe. No. L.83892. The only specimen.

LOCALITY AND HORIZON. 23 miles S.W. of Rahmu, N.E. Kenya ; Oxfordian,
Rahmu Shales.

62 JURASSIC BIVALVIA AND GASTROPODA

REMARKS. This species closely resembles Lima (Plagiostoma) punctata J. Sowerby,
of the Lias. Of comparable Upper Jurassic species, L. botdini Sauvage (de Loriol
1875 : 171, pl. 21, figs. 8, 9), Portlandian of northern France, is elongated in a more
oblique direction and its punctate grooves are more broadly spaced. L. libanensis
Krumbeck (1905 : 99, pl. 10, fig. 5), Lower Kimmeridgian of Syria, is described as
having distinctly raised but at the same time very depressed ribs, although this is not
obvious in the figures. JL. harronis Dacqué (1905 : 133, pl. 15, figs. 13, 14), Kim-
meridgian of Somaliland, is a narrower and more oblique shell with distinctly raised
ribs. L. thisbe de Loriol (1888 : 322, pl. 36, figs. 1-4), Lower Kimmeridgian of the
French Jura, and L. burensis de Loriol (1893 : 331, pl. 34, figs. 11, 12 ; 1895 : 47,
pl. 9, fig. 2) and L. trembiazensis de Loriol (1901 : 102, pl. 5, fig. 24), both from the
Upper Oxfordian of the Swiss Jura, have distinctly raised ribs separated by punctate
grooves which are more closely spaced than in the form now described.

Lima (Plagiostoma) sublaeviuscula Krumbeck
Pl. 8, figs. 5, 6

1905. Lima sublaeviuscula Krumbeck : 99, pl. 3, figs. 3a, b.

MATERIAL. Two specimens.

LOCALITY AND HORIZON. 5 miles S. of Galgali Gambo, N.E. Kenya ; Upper
Kimmeridgian, Dakacha Limestones.

REMARKS. These specimens, the larger of which is about 80 mm. high, are larger
than Krumbeck’s type-specimen, but are similar to it in shape and have exactly the
same characteristic ornament of very depressed radial ribs which are unequal and
irregularly spaced, and are confined to the anterior, posterior and ventral parts of
the surface, the middle of which is smooth. The intervals between the ribs are
relatively narrow and do not seem to be punctate. It seems doubtful if L. informis
Krumbeck (1905 : 100, pl. 3, figs. 7a—c) is specifically distinct from L. sublaeviuscula,
although stated to be less inequilateral, higher in proportion to its breadth and more
gibbose, and to have a shorter and broader lunule. Both forms, described originally
from the Lower Kimmeridgian of Syria, differ only in minor details from the Upper
Oxfordian species L. laeviuscula (J. Sowerby), in which the shell seems to be slightly
broader and the ribs less numerous. A specimen (L.g2235) from the Seir Limestones
(Oxfordian) of N. Kenya identified (Joubert 1960, pl. 8, fig. 6) as Lima (Plagiostoma)
cf. laeviuscula may well belong to Sowerby’s species, but is broken anteriorly and too
imperfect for definite identification.

Subgenus ACESTA Adams 1858

Lima (Acesta) kindopeensis sp. nov.
PLS, fig. xO

Di1aGnosis. Of medium size (height of holotype c. 47 mm.), ovate-trapezoidal,
with a slight lunate tendency ; length, parallel to hinge-margin, almost equal to

FROM TANGANYIKA AND KENYA 63

height ; posterior margin short, ventral margin strongly asymmetrical, feebly con-
vex posteriorly, strongly convex anteriorly. Inflation weak. Umbonal region
sharply rounded in outline, its angle less than a right angle. Anterior umbonal
ridge rounded off, fading away before reaching somewhat upturned antero-ventral
part of shell. Lunule short, well excavated. Posterior auricle small and obtuse,
anterior auricle virtually absent. Ornament consisting of 43 broad, depressed ribs
which are interrupted by irregularly and rather distantly spaced growth-rugae and
in the holotype are deflected in an anterior direction at the stage when the shell was
about three-quarters fully grown. Intervals between ribs narrow and shallow,
apparently not punctate.

HorotyrPe. No. L.56240. The only specimen.

LOCALITY AND HORIZON. Kindope, N.N.W. of Tendaguru, Tanganyika ; Upper
Kimmeridgian, Nerinella Bed.

Remarks. Although much of the holotype is an internal mould, the original
shell is preserved in places, particularly in the antero-ventral region. This species
is comparable to L. monsbeliardensis Contejean (de Loriol 1872 : 377, pl. 22, figs. 2,
2a), from the Lower Kimmeridgian of Europe, but has fewer ribs and also differs in its
somewhat lunate outline. In L. virvgulina Contejean (1860 : 308, pl. 23, figs. I, 2),
another rather similar species from the Kimmeridgian of Europe, the ribs are even
more numerous. In L. meroe de Loriol (1894a : 151, pl. 10, figs. 17, 18), Lower
Kimmeridgian of France, there are about 60 ribs and a distinct anterior auricle is
present.

Lima (Acesta) cutleri sp. nov.
P18; fig..9

SPECIFIC NAME. After the late W. E. Cutler, the first leader of the British Mu-
seum East Africa Expedition.

Diacnosis. Relatively small, narrowly subovate, broadening ventrally, and
with a slight lunate tendency ; height much exceeding length ; inflation moderate.
Posterior and ventral margins forming an uninterrupted curve, the lower part of
which is strongly and asymmetrically convex ; anterior margin very slightly con-
cave. Umbonal region narrow, no distinct umbonal ridges ; no lunule. Posterior
auricle obtuse, not distinctly delimited from body of shell ; anterior auricle virtually
absent. Ornament consisting of slightly sinuous, punctate, linear grooves, the
intervals between which are flat and do not form distinct ribs except on anterior part
of surface, where they are slightly elevated. Grooves close together on posterior
part of surface but more widely spaced on anterior part ; their total number exceeds
60. There are also a few well-marked and very irregularly distributed growth-
rugae.

HOLOTYPE AND PARATYPES. Holotype, no L.52033. There are several paratypes.

LOCALITIES AND HORIZON. Tingutitinguti creek (type-locality) ; Nitongola
creek, and Kindope valley, all near Tendaguru, Tanganyika ; Upper Kimmerid-
gian, “ Trigonia smeei’”’ Bed.

64 JURASSIC BIVALVIA AND GASTROPODA

REMARKS. This shell is much narrower than L. kindopeensis sp. nov., described
above, and also differs in the absence of a distinct anterior umbonal ridge and lunule
and of distinct radial ribs except on the anterior part of the surface.

Genus PSEUDOLIMEA Arkell 1932

Pseudolimea duplicata (J. de C. Sowerby)
Pl. 8, figs. 8a, b

1827a. Plagiostoma duplicata J. de C. Sowerby : 114, pl. 559, fig. 3.

1932a. Lima (Pseudolimea) alternicosta Buvignier ; Arkell : 140, pl. 13, figs. 3-5.
1933. Lima (Radula) sp. ; Dietrich : 63, pl. 7, figs. 96-98.

1944a. Pseudolimea duplicata (Sow.) ; Cox: 84.

1952. Pseudolimea duplicata (Sow.) ; Cox: 60, pl. 5, figs. 11, 12.

MATERIAL. Several specimens.

LOCALITIES AND HORIZONS. Kulong, 2 miles S.W. of Muddo Erri, N.E. Kenya ;
Callovian [?-Lower Oxfordian], Muddo Erri Limestones. Dussé, 14 miles S.E. of
Rahmu, N.E. Kenya ; Upper Oxfordian, Seir Limestones. Kindope, N.N.W. of
Tendaguru, Tanganyika ; Upper Kimmeridgian, Nerinella Bed.

REMARKS. The Pseudolimea which occurs in some abundance at Tendaguru and
was recorded as Lima (Radula) sp. by Dietrich does not appear to be distinguishable
specifically from the long-ranging species P. duplicata, the synonymy of which is
given in my two papers cited above. The largest Tendaguru specimens are, indeed,
only 13 mm. high and thus smaller than specimens from many localities, but the
general proportions of the shell, the number of ribs (22) and their V-shaped cross-
section, and the presence of a radial thread in each interval are exactly as in P.
duplicata. The specimens from lower horizons in northern Kenya are in every way
typical. The known range of the species in Europe is from Toarcian to Upper
Oxfordian, with an unconfirmed record from the Portlandian.

Pseudolimea mandawaensis sp. nov.
BLS ne .3

DiacGnosis. Large for a Pseudolimea, broadly trapeziform, length and height
about equal (c. 40 mm.), ventral margin strongly asymmetrical, umbonal region
slightly obtuse. Postero-dorsal region only slightly impressed ; auricles unknown.
Main ribs about 23, obtusely angular, depressed, with broadly rounded, slightly un-
equal intervals bearing numerous fine, unevenly spaced radial threads with one near
middle slightly more prominent than the others ; in addition, a few weak, jagged radial
riblets occupy anterior and posterior ends of shell. Concentric ornament, except
near ventral margin, consisting of closely and evenly spaced threads which are even
more delicate than the radials ; late growth stages, however, are marked by irregular
concentric rugae.

FROM TANGANYIKA AND KENYA 65

HoLtotyrPe. No. LL.35100, ex B.P. Coll. The only specimen.

LOCALITY AND HORIZON. Lihimaliao creek, Mandawa area, Tanganyika ; Upper
Oxfordian.

REMARKS. The original convexity of the holotype, a rather crushed specimen,
does not appear to have been very strong. The ornament recalls that of the two
Liassic species Pseudolimea pectinoides (J. Sowerby) and P. rvoemeri (Brauns), and,

although its internal characters are unknown, the species is referred to Pseudolimea
with some confidence. Lima mistrowitzensis Boehm (1883 : 638, pl. 69, figs. 21, 22),
from the Tithonian Stramberg beds, is a comparable species, but has fewer radial
_tibs.

Genus LIMATULA Wood 1839

Limatula moorei sp. nov.
Pl. 8, figs. 7a, b

SPECIFIC NAME. After Mr. W. R. Moore, of the Tanganyika Geological Survey,
collector of the holotype.

DiaGnosis. Small (height 9:0 mm., length 7-0 mm.), tall, ovate, slightly asym-
metrical, with prominent umbo ; surface evenly inflated. Ornament confined, as
in all Limopsis, to median part of flank, and consisting of smooth, rounded, not very
prominent ribs separated by intervals which are only about one-third as wide as
ribs and bear delicate growth-threads near ventral margin. Ribbed part of surface
merges gradually on both sides into smooth anterior and posterior parts ; number
of ribs, apart from very weak outer ones, about 15.

Ho.LotyPe. No. LL.16799, a right valve. The only specimen.

| Locality AND HORIZON. Usigiwa river, 6 miles W.S.W. of Kiwangwa, Baga-
moyo hinterland, Tanganyika ; Upper Oxfordian.

Remarks. The broadly rounded ribs and narrow intervals distinguish this form
from most of the species of Limatula described previously from the Middle and Upper
| Jurassic, including L. boehmi de Loriol, L. consobrina (d’Orbigny), L. gerassimovi
| Pchelintsev, L. gibbosa (J. Sowerby), L. globularis Laube, L. helvetica (Oppel), L.
oxfordiana Maire, L. praedispersa Krause, and L. rauracica Cossmann. In L.
minutissima (d’Orbigny) (= Lima minuta Roemer non Goldfuss ; synonym, Lima
_ suprajurensis Contejean) the ribs are just as broad as in the species now described,
but they are scaly or tuberculate, while the shell itself is more distinctly truncated
posteriorly.

\

Limatula migeodi sp. nov.
Pl. 8, figs. 4a, b

_ SPECIFIC NAME. After the late F. W. H. Migeod, for some years leader of the
British Museum East Africa Expedition.

DraGnosis. Small (height of holotype 10-5 mm.), ovate, breadth nearly three-
quarters of height ; slightly oblique. Auricles moderately large, obtuse-angled, the

66 JURASSIC BIVALVIA AND GASTROPODA

posterior slightly the larger. Median part of valve ornamented with 13 angular
costae which are separated by slightly narrower, angular intervals and bear small,
evenly spaced nodes. Ribbed area sharply separated from anterior and posterior
parts of surface, which are smooth except for a few faint radial lines and growth-
lines.

HOLOTYPE AND PARATYPE. Nos. LL.11514, LL.11515 respectively.

LOCALITY AND HORIZON. Kindope, N.N.W. of Tendaguru, Tanganyika ; Upper
Kimmeridgian, Nerinella Bed.

REMARKS. A species Limatula tendagurensis Lange (1914 : 207, pl. 15, figs. 6a, b)
was described from the Neocomian of Tendaguru, and Dietrich (1933 : 63) has stated
that it ranges throughout the whole series of beds at that locality. The Jurassic
form now described differs, however, from Lange’s figures in its more strongly con-
vex anterior and posterior margins and its broader proportions. It also has fewer
ribs, the number mentioned by Lange being 15-17 in addition to some weaker ones
which extend on to the lateral parts of the surface.

Genus CTENOSTREON Eichwald 1862
Ctenostreon proboscideum (J. Sowerby)

1820a. Lima proboscidea J. Sowerby : 115, pl. 264.

1932a. Ctenostreon proboscideum (Sowerby) ; Arkell: 145, pl. 15, fig. 3.
1937. Ctenostveon proboscideum (Sowerby) ; Hennig: 180.

1960. Ctenostreon proboscideum (Sowerby) ; Joubert : pl. 8, fig. 7.

MATERIAL. One specimen (no. L.g2184).

LOCALITY AND HORIZON. Melka Dakacha, N.E. Kenya ; Upper Kimmeridgian,
Dakacha Limestones.

RemARKsS. The specimen now recorded is a relatively small, ill-preserved internal
mould with about nine radial ribs. The species was recorded by Hennig from beds
thought to be Kimmeridgian in age at a locality in the Mandawa district of Tangan-
yika.

Superfamily OSTREACEA
Family OSTREIDAE Rafinesque 1815
Genus LOPHA Roeding 1798
Lopha costata (J. de C. Sowerby)
Pls; Hes: Fa, 07 €

1825a. Ostvea costata J. de C. Sowerby : 143, pl. 488, fig. 3.

1853. Ostrea costata Sow. ; Morris & Lycett : 3, pl. 1, figs. 5, 5a.
1856. Ostrea costata Sow. ; Quenstedt : 497, pl. 66, figs. 43, 44.
1863. Ostrea costata Sow. ; Martin : 65, pl. 5, figs. 12-15.

1868. Ostrea costata Sow. ; Lycett, pl. 34, fig. 3.

:
:
.

FROM TANGANYIKA AND KENYA 67

1883. Ostrea costata Sow. ; de Loriol : 77, pl. 11, figs. 8-17.

1888. Ostrea (Alectryonia) costata Sow. ; Schlippe : 113, pl. 1, figs. 11, 12.

1912. Alectyyonia costata Sow. ; Lissajous : 65, pl. 8, figs. 19, 20.

1916. Ostrea (Alectryonia) costata Sow. ; Jekelius : 230, pl. 4, figs. 3-6; pl. 6, fig. 9.
1923. Alectvyonia costata Sow. ; Cossmann : 4, pl. 5, figs. 5-8.

1924. Ostvea costata Sow. ; Cossmann : 24, pl. 2, figs. 61-64.

1924. Ostvea (Alectryonia) costata Sow. ; Hennig : 33, pl. 3, fig. 2.

1929. Avrctostrea costata (Sow.) ; Weir: 21, pl. I, fig. 17.

1933. Ostvea (Alectryonia) costata Sow. ; Ruiz, in Fabiani & Ruiz: 14, pl. 2, fig. 1.
1934). Lopha costata (Sow.) ; Arkell: 48, pl. 1, figs. 3-6.

1935. Lopha costata (Sow.) ; Cox: 173, pl. 17, fig. 13.

MATERIAL. One specimen (no. LL.35025) from the Toarcian and several from
later beds.

LOCALITIES AND HORIZONS. Didimtu hill, 2 miles S. of Bur Mayo, N.E. Kenya ;
Upper Lias, Toarcian, Didimtu Beds. 34 miles W. of Melka Bini, N.E. Kenya ;
Callovian, Rukesa Shales. S. of Rahmu—Melka Murri road, 6 miles W. of Rahmu,
N.E. Kenya ; Callovian [?-Lower Oxfordian], Muddo Erri Limestones.

DEscRIPTION. The Toarcian specimen now recorded is about 17 mm. high, with
a deep lower valve, the sides of which rise steeply from a rather large attachment
area. The sides have about 13 irregularly arranged costae, some of which have
arisen during growth by bifurcation of single costae, and which are prominent except
on the posterior and anterior ends of the valve. The costae are rounded at their
crests and are separated by deep but rounded intervals of about their own average
width. The upper valve is flat except for some irregularities and has a few weak
radial plications. The specimens from later formations call for no particular com-
ment.

REMARKS. I have hesitated before referring the Upper Liassic specimen to L.
costata, as typically this is a Bathonian species and records of its occurrence even as
early as the Bajocian have been queried (Whidborne 1883 : 492). Specimens from
the Bajocian of the Cotswolds which I would refer to the species are, however, in the
British Museum (Natural History). In typical specimens from the Great Oolite of
England, such as those figured by Morris & Lycett (1853) and by Arkell (19340), the
plications are smaller and more numerous than in the specimen now recorded, and
this is also the case in European Bathonian specimens figured by Schlippe (1888) and
Cossmann (1923). In those figured by Lissajous (1912), however, the ribbing is of
about the same strength as in the present shell, and this is also the case in the English
Inferior Oolite specimens already mentioned. Cossmann (1924) has referred to the
variability of specimens of L. costata from the French Callovian, and has stated that
the number of ribs ranges from 12 to 18 irrespective of the geological horizon. L.
costata is here accepted as a species ranging from Toarcian to Callovian, the present
being the first record of its occurrence in the former stage. Thevenin (19080 : 21,
pl. 4, figs. 10, 10a) has recorded a small plicated oyster from the Upper Lias of
Madagascar under the name Ostrea subserrata Goldfuss, although Goldfuss’s species
is now known to have been a Plicatula. The specimen from Madagascar has narrow-

68 JURASSIC BIVALVIA AND GASTROPODA

and, apparently, more lamellose plications than the shell now recorded ; it most
probably also belongs to L. costata.

Lopha olimvallata nom. nov.
Pl. 9, figs. 2a, b

1874. Ostvea vallata Dumortier : 203, pl. 45, figs. 7, 8 (won Thurmann & Etallon, 1862).
1905. ? Osivea sp. ; Benecke: 16x, pl. 12, fig. 12.

1929. Alectryonia vallata Dumortier ; Schafle : 64, pl. 6, figs. 6-8.

1935. Alectryonia vallata Dumortier ; Kuhn : 1109, pl. 8, fig. 30.

MATERIAL. One specimen (no. LL.35026).

LOCALITY AND HORIZON. Didimtu hill, 2 miles S. of Bur Mayo, N.E. Kenya ;
Upper Lias, Toarcian, Didimtu Beds.

DESCRIPTION. This specimen is an elongated, linguiform, shallow left valve 51
mm. high and 20 mm. broad, attached by almost its entire surface to a lamina of
fibrous calcite, to the other side of which some smaller and less complete right valves
are attached. The low sides of the valve rise steeply from the attachment area and
have a number of rather weak, irregular plications. The umbo is directed in an
anterior direction to a slight extent.

REMARKS. In the type-specimen of Ostvea vallata, which came from the Upper
Lias of southern France, and in specimens from the Upper Lias of Germany figured
by Schafle, the height of the shell is only slightly in excess of the breadth. In the
shell from the Aalenian of Lorraine figured by Benecke as “ Ostrea sp.’’, and con-
sidered by Schafle to belong to Dumortier’s species, the shape is narrow and lingui-
form and the umbo is directed anteriorly exactly as in the specimen now recorded,
although the plications of the shallow sides of the valve are stronger and more
numerous. The present specimen is thought to be referable to Dumortier’s species
as interpreted by Schafle and now renamed.

Lopha gregarea (J. Sowerby)
Pl. 9, fig. 5
1815a. Ostvea gregavea J. Sowerby : 109, pl. 111, figs. 1, 3.
1933a. Lopha gregavea (Sowerby) ; Arkell: 183, pl. 22, figs. 5,6; pl. 23, figs. 1-4.
1952. Lopha gregavea (Sowerby) ; Cox: 96, pl. 4, fig. 2 ; pl. 10, figs. 7-13.
1960. Lopha gregavea (Sowerby) ; Joubert, pl. 9, fig. 1.

MATERIAL. Several specimens.

LOCALITIES AND HORIZONS. 34 miles W. of Melka Biini ; also hills S. of Rahmu-
Melka Murri road, 11 miles and 13 miles W. of Rahmu, N.E. Kenya ; Callovian,
Rukesa Shales. S. of Rahmu—Melka Murri road, 6 miles W. of Rahmu, N.E.
Kenya ; Callovian [?-Lower Oxfordian], Muddo Erri Limestones. 13? miles S.W. of
Rahmu and 6} miles S.S.W. of Rahmu, N.E. Kenya ; Oxfordian, Rahmu Shales.
Wilderri hill, 1r miles $.S.W. of Rahmu, N.E. Kenya ; Upper Oxfordian, Seir

FROM TANGANYIKA AND KENYA 69

Limestones. 3 miles N.E. of Melka Dakacha, N.E. Kenya ; Upper Kimmeridgian,
Dakacha Limestones. 14 miles E. of Kidugallo Station, Central Railway, Tangan-
yika ; Bajocian, Station Beds.

Lopha eruca (Defrance)

1821. Ostvea evuca Defrance : 31.

1857. Ostrea hastellata [vastellata] Quenstedt : 750, pl. 91, figs. 26, 27.

1930. Arctostrea hastellata (?non Quenstedt ; de Loriol) ; Weir: 85, pl. 9, fig. 4.
1938. Lopha krvumbecki Weir: 45, pl. 3, fig. 7.

1952. Lopha eruca (Defrance) ; Cox: 103, pl. 11, figs. 1-7.

MATERIAL. One internal mould (no. LL.35101), ex B.P. Coll.

LOCALITY AND HORIZON. 4} mile from Msata on road to Bagamoyo, Tanganyika ;
Callovian or Oxfordian (in friable brown sandstone).

Remarks. Although merely an internal mould, this specimen undoubtedly be-
longs to Defrance’s species, the full synonymy of which is given in my paper cited
above. There is little doubt that the specimens from Kenya recorded by Weir
(1930, 1938) belong to this species.

Lopha cf. intricata (Contejean)
Pl. 9, figs. 8a, b

1860. Cf. Ostvea intricata Contejean : 323, pl. 25, figs. 6-8.

MATERIAL. One specimen (no. L.83899).

LOCALITY AND HORIZON. 63 miles S.S.W. of Rahmu, N.E. Kenya ; Oxfordian,
Rahmu Shales.

Remarks. This is a tall, oval, slightly oblique and lunate, weakly inflated speci-
men, 44 mm. in height and 28 mm. broad, with a large attachment area from which
the walls of the lower valve, folded into plications of small amplitude, rise vertically
to the commissure. The upper valve, which has an irregular surface, is weakly con-
vex and also plicated at its margins. Except that its lower valve is not quite so deep,
this specimen agrees well with Contejean’s figure of the holotype of Ostrea intricata,
a specimen of Lower Kimmeridgian age. In O. vallata Etallon (de Loriol 1894) : 75,
pl. 9, figs. 5, 6), from the Swiss Oxfordian, the plications are sharper and more num-
erous. It is difficult to say whether or not these specimens are merely examples of
better-known species of Lopha in which the development of plications on both
valves has been restricted by an unusually large attachment-area.

Lopha solitaria (J. de C. Sowerby)
Plto} fig: 4

1824a. Ostrea solitaria J. de C. Sowerby : 105, pl. 468, fig. 1.

1933a. Lopha solitaria (Sowerby) ; Arkell: 185, pl. 22, fig. 4; pl. 23, figs. 5-7.
1935a. Lopha solitaria (Sowerby) ; Cox: 171, pl. 17, figs. 9-12.

1960. Lopha solitaria (Sowerby) ; Joubert, pl. 9, figs. 2a—-c.

7o JURASSIC BIVALVIA AND GASTROPODA

MATERIAL. Several specimens.

LOCALITIES AND HORIZONS. 1? miles S.W. of Rahmu, N.E. Kenya, and river
section W. of Rahmu-—E] Wak road, 54 miles S.W. of Rahmu ; Oxfordian, Rahmu
Shales. Golberobe hills, N.E. Kenya ; Oxfordian, Golberobe Beds. Dussé, 1}
miles S.E. of Rahmu, N.E. Kenya, and Wilderri hill, 11 miles S.S.W. of Rahmu ;

Upper Oxfordian, Seir Limestones. Chamgamwe, near Mombasa, Kenya ; Kim-
meridgian, Chamgamye Shales.

Lopha tifoensis sp. nov.
Pl. ros hes: 2, 05.7
1957. Lophasp. ; Saggerson & Miller : 20, fig. e.

DiaGnosis. Shell small (height of largest specimen 27 mm.), trigonal to ovate,
variable in proportions but usually higher than long, with deep but relatively thin-
shelled lower valve and flat upper valve. Attachment-area conspicuous, fairly large
in some specimens, terminal, truncating the umbonal region. Surface of lower valve
with a series of irregularly distributed, rounded costae, some fading away during
growth while others appear by intercalation and bifurcation, diverging to margins
from points close to attachment-area. Where they first appear the number of
costae is about 4-6 ; in the holotype, a specimen 14 mm. high, and in the largest
paratype, mentioned above, the number of costae reaching the margin is about 10,
but in another specimen, 18 mm. high, the number is 16. Upper valve with de-
pressed, rounded radial costae originating at same stage of growth as in lower valve.

HOLOTYPE AND PARATYPES. Holotype, no. L.g3574; several paratypes, of
which L.93561, L.93563 and L.93580 are figured.

LOCALITIES AND HORIZON. Tifo (type-locality), Korkai Hammassa, Ogar Wein,
Chimpa, and Asahaba, all N.E. Kenya ; Oxfordian, Golberobe Beds.

REMARKS. While in most specimens the height considerably exceeds the length,
the specimen represented in fig. 2 is remarkable for its quadrate outline. Its
attachment-area is unusually large and its ribs very weak. Some specimens of this
species were originally identified as Lopha costata (J. de C. Sowerby), to which it
appears to be closely related. It differs from Sowerby’s species, however, in its much
more depressed and rounded costae.

Lopha ? kindopeensis sp. nov.
Pi 10; figs=3, 44,0, 5

DiaGnosis. Moderately large (height of holotype 96 mm.), trapezoidal, typically
with more or less straight anterior and posterior margins diverging from the base of
a broad ligamental area, and tending to be subangular postero-ventrally. Both
valves fairly thick-shelled and almost flat, differing very little in convexity. (The
left valve, however, is known only by imperfect specimens mostly growing attached
to the greater part of the surface of right valves, the exteriors of which are thus

FROM TANGANYIKA AND KENYA 71

obscured although their interiors are well exposed.) Adductor scar large. Margins
of both valves with rounded, unevenly spaced plications which scarcely extend on
surface of shell even where this is not obscured by adherent specimens. In one
specimen which appears to be a left valve (although this is not altogether certain as
its dorsal half is broken away) the somewhat eroded surface bears unevenly arranged,
discontinuous pustules and superficial ribs.

HOLOTYPE AND PARATYPES. Holotype, no. L.54855 ; four paratypes, of which
L.54856 and L.54858 are figured.

LOCALITIES AND HORIZON. Kindope (type-locality), and N. of Kinjele, both near
Tendaguru, Tanganyika ; Upper Kimmeridgian, Nerinella Bed.

Remarks. This form, with its weak plications confined to the margins, appears
to lie on the border-line between Ostrea and Lopha. It is much larger but relatively
less inflated than Lopha intricata (Contejean), referred to above, and also differs in
its angular outline.

Lopha hennigi (Dietrich)
1933. Alectryonia hennigi Dietrich : 70, pl. 10, figs. 144, 145.

MATERIAL. Several specimens.

LOCALITIES AND HORIZONS. Mtapaia road and Kipande path, near Tendaguru,
Tanganyika ; Upper Kimmeridgian, “Tvigonia smeei’’ Bed. Kindope, near
Tendaguru, Tanganyika ; Upper Kimmeridgian, Nerinella Bed.

Remarks. This is a large, thick-shelled oyster with strong, angular, unequal
plications, bifurcating in places. It is closely related to the widespread Jurassic
species L. marsh (J. Sowerby), which occurs at lower horizons in East Africa, but
is represented only by poor and somewhat doubtful specimens in the material
studied.

Genus LIOSTREA Douvillé 1904
Liostrea dubiensis (Contejean)

1860. Ostvea dubiensis Contejean : 320, pl. 21, figs. 4-11.
1935a@. Ostrea (Liostrea) dubiensis Contejean ; Cox: 171, pl. 17, figs. 4, 5.

MATERIAL. Numerous specimens.

LOCALITIES AND HORIZONS. I mile and 2 miles W. of Magindu Station, Central
Railway, Tanganyika ; about Bathonian. 1 mile N. of Asaharbito, N.E. Kenya ;
Bathonian [? or Callovian}, Asaharbito Beds. Ogar Wein and Golberobe hills, N.E.
Kenya ; Oxfordian, Golberobe Beds. Dussé, 14 miles S.E. of Rahmu, N.E. Kenya ;
Upper Oxfordian, Seir Limestones. Kiwato—Mkange track, 5 miles S.S.E. of Mkange,
Bagamoyo hinterland, Tanganyika ; Oxfordian or Kimmeridgian. Tingutitinguti
creek and Kindope, both near Tendaguru, Tanganyika ; Upper Kimmeridgian,
“ Trigonia smeet”’ and Nerinella Beds.

72 JURASSIC BIVALVIA AND GASTROPODA

Liostrea polymorpha (Minster)
Plitg; fies! 33°7a, °b

1833. Gryphaea polymorpha Minster, in Goldfuss : 31, pl. 86, figs. 1a, b.
1835. ‘‘ Unbestimmt’’; Roemer, pl. 3, fig. 12.

1843. Ostrea rémeri Quenstedt : 434.

1857. Ostrea romeri Quenstedt ; Quenstedt : 625, pl. 77, figs. 22, 23 (?).
1878. Ostvea voemeri Quenstedt ; de Loriol : 165, pl. 23, fig. 4.

1881. Ostvea voemeri Quenstedt ; de Loriol : 96, pl. 13, fig. 7.

1917. Ostrea polymorpha (Minster) ; Rollier : 592.

1931. Gvryphaea roemeri (Quenstedt) ; Pchelintsev : 67.

MATERIAL. Three specimens, including nos. LL.35102-03, all ex B.P. Coll.

LOCALITY AND HORIZON. Lihimaliao creek, Mandawa area, Tanganyika ; Upper
Oxfordian.

REMARKS. Ostrea rvoemeri is included in the synonymy of Gryphaea polymorpha
on the authority of Rollier and Pchelintsev. G. polymorpha has been misinterpreted
by a number of authors as the Lower Bajocian species which has been well figured by
Benecke (1905 : 162, pl. 11, figs. 1-3) under its correct name Gryphaea ferruginea
(Terquem). Both forms lie on the border-line between Liostrea and Gryphaea, the
right valve being almost flat and the left valve feebly convex.

The specimens now recorded are subquadrate to suborbicular in outline and the
largest was originally about 70 mm. high. Their general shape is, therefore, rather
similar to that of the shell figured by de Loriol in 1881 as Ostrea roemeri. They are
broader than Roemer’s figure upon which this latter species was founded and Quen-
stedt’s fig. 22, but in the upper valve of the better preserved specimen (fig. 7b) the
beak is directed posteriorly in much the same manner as in the figures of these
authors. This specimen has a relatively large attachment area whereas that of the
specimens figured by previous authors is small.

The type specimen of L. polymorpha came from the Upper Jurassic (probably
Lower Kimmeridgian) of Streitberg,in Franconia. Of the oysters from Cutch, India,
described by the present writer (Cox 1952), ‘““Gryphaea sp. indet.” (pl. 9, figs. 3a-c)
from the Upper Oxfordian seems very close to the specimens now described and
could belong to L. polymorpha.

Subgenus CATINULA Rollier 1911

Liostrea (Catinula) alimena (d’Orbigny)
Pl. 9, figs. 6a, b
1840b. Exogyrva conica J. de C. Sowerby, pl. 22, fig. 27 (non J. Sowerby sp.).
1850. Ostrea alimena d’Orbigny : 343.
1934b. Ostrea (“ Catinula’’) alimena d’Orbigny ; Arkell : 34, pl. 5, figs. 1-15.
1952. Liostrea (Catinula) alimena (d’Orbigny) ; Cox : 76, pl. 6, figs. 7-10.
1960. Ostvea (Catinula) cf. ancliffensis Cox & Arkell ; Joubert, pl. 8, fig. 8.

MATERIAL. Several specimens.
LOCALITIES AND HORIZONS. 34 miles W. of Melka Biini, also 11 miles W. of

FROM TANGANYIKA AND KENYA 73

Rahmu, N.E. Kenya ; Callovian, Rukesa Shales. Kulong, 2 miles S.W. of Muddo
Erri, also top of hills S. of Rahmu—Melka Murri road, 10 miles W. of Rahmu, N.E.
Kenya ; Callovian [?-Lower Oxfordian], Muddo Erri Limestones. Magindu,
Central Railway, and 2 km. to the east, Tanganyika ; Callovian.

REMARKS. The specimens now recorded fall within the range of variation of L.
alimena as described (Cox 1952) from the Callovian and Oxfordian of Cutch, India.
It is difficult to define any difference between this species and L. ancliffensis Cox &
Arkell (1948 : 20), from the Bathonian, so far as the general form of the shell is
concerned, but L. ancliffensis does not exceed 11 mm. in height whereas L. alimena
commonly attains a much larger size. Certainly the numerous small specimens in
an oyster bed of which a fragment was figured by Joubert (1960) could not be sepa-
rated from L. ancliffensis, but other specimens from the same formation (the Rukesa
Shales) are larger. The radial ribs present in many English specimens referred to
this species and described by Arkell (19346) have not been observed in specimens
from Cutch or from East Africa.

Genus GRYPHAEA Lamarck 1801

Gryphaea hennigi Dietrich
Pl. 21, figs. ta, Bb
1900. Gvryphaea lobata Quenstedt ; Miiller : 521, pl. 16, figs. 6, 6a.

1925. Gvryphaea hennigi Dietrich : 6, pl. 2, fig. 4.
1952. Gryphaea hennigi Dietrich ; Cox: 83, pl. 8, figs. 7(?), 8, 9a-c.

MATERIAL. Three left valves (nos. LL.16848—50).

LOCALITY AND HORIZON. Look-out hill opposite Kingura village, north of Wami
river, Tanganyika ; Upper Oxfordian.

REMARKS. The most notable feature of these specimens is the protruding lobe-
like antero-ventral region, and in one specimen the growth-rugae show that this was
separated from the rest of the valve by a broad sinus of the ventral margin. The
specimens are broken away posteriorly, but the largest appears from the growth-
rugae to have had a rather similar postero-ventral lobe. They appear to belong to
Gryphaea hennigi, which, according to Aitken (1961 : 25) is abundant in the Lower
Kimmeridgian Septarian Marl of the Mandawa—Mahokondo anticline. They are also
extremely close to G. moondanensis Cox (1952 : 87, pl. 9, figs. 4, 7, 8), a species from
the Tithonian of Cutch, north-western India, in which an antero-ventral lobe is a
conspicuous feature.

Genus EXOGYRA Say 1820

Exogyra nana (J. Sowerby)
Phere digss 560510
1822a. Gryphaea nana J. Sowerby : 114, pl. 383, fig. 3.

1872. Ostvea bruntrutana Thurmann ; de Loriol : 399, pl. 24, figs. 7-18.
1929. Evxogyra nana (J. Sowerby) ; Weir : 20, pl. 1, figs. 11-13.

74 JURASSIC BIVALVIA AND GASTROPODA

1930. Exogyra nana (J. Sowerby) ; Weir: 85, pl. 10, figs. 27-29.
1952. Evxogyra nana (J. Sowerby) ; Cox: 92, pl. 10, figs. 2-4.

MATERIAL. Several specimens.

LOCALITIES AND HORIZONS. Ogar Wein and Tifo, N.E. Kenya; Oxfordian,
Golberobe Beds. 2} miles S.W. of Rahmu, N.E. Kenya ; Oxfordian, Rahmu Shales.
Hereri river crossing, 3 miles S. of Melka Kunha, N.E. Kenya ; Kimmeridgian,
Hereri Shales. Kiwate—Mkange track, 5 miles $.S.E. of Mkange, Bagamoyo hinter-
land, Tanganyika ; Oxfordian or Kimmeridgian. Kindope valley, near Tendaguru,
Tanganyika ; Upper Kimmeridgian, Nerinella Bed.

REMARKS. Most of the specimens are irregular in form, but some from the Rahmu
Shales are characterized by their regularly lunate outline, recalling that of the larger
form E. fourtauwi Stefanini (see Cox 19354 : 174, pl. 17, figs. 14a, b). Occasional
European specimens of FE. nana (e.g. de Loriol 1872, pl. 24, figs. 12, 12a, b) are, how-
ever, similar in shape.

Superfamily TRIGONIACEA
Family TRIGONIDAE Lamarck 1819
Genus TRIGONIA Bruguiére 1789

Trigonia costata Parkinson
Pl. 11, figs. 2a, b

1811. Tvigonia costata Parkinson : 175, pl. 12, fig. 4.
1875. Tvigonia costata Sowerby ; Lycett : 147, pl. 29, figs. 5—I0.
1932. Lyriodon costatum (Sowerby) ; Lebkiichner : rot, pl. 15, fig. 9; pl. 16, fig. 3.

MATERIAL. One specimen (no. LL.35104), ex B.P. Coll.

LOCALITY AND HORIZON. Magole, 5 miles N.W. of Kidugallo, Tanganyika ;
Bajocian.

REMARKS. This small specimen, about 18 mm. long and 16 mm. high, appears
to be referable to the true 7. costata, a Bajocian species which has been much mis-
interpreted. The angular concentric ribs, 16 in number, almost touch the marginal
carina in the right valve, but are separated from it in the left by an ante-carinal
depression which is fairly narrow, although broader than in the new species T. kentt,
described below. The posterior area bears a relatively prominent nodose rib the
position of which is anterior to median. Between this rib and the marginal carina
is a single nodose thread and on its posterior side are three other threads, irregularly
arranged. The escutcheon has a few transverse wrinkles. These features are similar
to those of English specimens of T. costata which have reached the same stage of
growth. Previous records of 7. costata from East Africa are from post-Bajocian
beds and are to be rejected.

FROM TANGANYIKA AND KENYA 75

Trigonia kidugalloensis sp. nov.
Ph x1,-fes. 3¢,°b, ¢

HOLOTYPE AND PARATYPE. Holotype, no. LL.35105 ; one paratype, no. LL.
35106. Both ex B.P. Coll.

DiaGnosis. Small (length of holotype, when complete, c. 17 mm.), rather
strongly inflated, length and height nearly equal, umbones not prominent ; curva-
ture of marginal carina very feeble ; posterior area moderately broad, concave
transversely and forming a relatively wide angle with the flank ; ventral margin
apparently evenly convex. Flank ornamented with relatively narrow and numer-
ous, evenly curved, round-topped concentric ribs separated by intervals of about
the same width ; number of ribs on each valve of holotype 27. ___Ribs end a short
distance from the prominent, serrated marginal carina, which is thus bordered by an
ante-carinal groove, slightly wider in left valve than in right. The area has no
marked median carina or groove, but bears 6-7 nodose radial threads, and the es-
cutcheon carina is also nodose.

LOCALITY AND HORIZON. 14 miles N.N.W. of Kidugallo, Tanganyika ; Bajocian.

REMARKS. This form resembles the European Bajocian species T. henusphaerica
Lycett (re-described Lycett 1877 : 174, pl. 31, figs. 4-8 ; pl. 33, figs. 4-6 (var. gre-
garia)) in the closeness of the spacing of its concentric ribs, but it is less elongate and
more strongly inflated, and has a more distinct ante-carinal groove, especially on the
left valve. The broader ante-carinal groove and less prominent umbo distinguish
the new species from T. hemisphaerica race asiatica Douvillé (1916 : 29, pl. 4, fig. 9),
from the Bajocian of Sinai. In the French Bajocian species T. gadoist Cossmann
(1912 : 8, pl. 1, figs. 6-8) the concentric ribs are still more closely arranged.

Trigonia kenti sp. nov.
Ply 11) figs. 4a, 0, €

SPECIFIC NAME. After Dr. P. E. Kent, of the British Petroleum Company,
Limited.

HOLOTYPE AND PARATYPE. Holotype, no. LL.35107 ; one paratype, no. LL.
@5108.. Both ex B.P. Coll.

Diacnosis. Small (length of holotype 22 mm.), moderately inflated, length
slightly exceeding height, umbones moderately prominent and acute ; ventral
margin tending to be subangular in middle and slightly sinuate posteriorly ; posterior
area rather narrow, forming relatively low angle with flank. Flank ornamented
with rather angular concentric ribs which are curved irregularly in places and are
moderately wide-spaced (about 2 mm. apart) until a relatively late growth-stage, but
become crowded together near ventral margin. The ribs extend in both valves al-
most to the sharp and not strongly nodose marginal carina, the ante-carinal depres-
sion being very narrow. Posterior area feebly convex, with a median rib which is most
conspicuous in earlier stages of growth and with about four very irregularly spaced

76 JURASSIC BIVALVIA AND GASTROPODA

radial threads. Escutcheon carina apparently weakly serrated (but eroded in
available specimens).

LOCALITY AND HORIZON. 6 miles N.W. of Kidugallo, Tanganyika ; Bajocian.

REMARKS. The crowding together of the concentric ribs near the ventral margin
suggests that the two specimens studied, although small, are full-grown representa-
tives of their species. This feature, the irregular curvature of the ribs in places, and
the very narrow ante-carinal depression distinguish this species from T. costata
Parkinson.

Trigonia cf. brevicostata Kitchin
Pl rr hie 7

1903. Cf. Tvigonia brevicostata Kitchin : 23, pl. 2, figs. 4, 5.
1939. Cf. Trigonia brevicostata Kitchin ; Stefanini: 224, pl. 24, figs. 11, 12.
1952. Cf. Trigonia brevicostata Kitchin ; Cox: 112.

MATERIAL. Four imperfect specimens.

LOCALITY AND HORIZON. 1 mile N. of Asaharbito, N.E. Kenya ; Bathonian [? or
Callovian], Asaharbito Beds.

REMARKS. The specimens are internal and external moulds of the original shells,
the largest of which was originally almost 30 mm. long although the others are much
smaller. The ornament consists of well separated, coarse concentric ribs which
swing down to some extent and swell out at their posterior end ; they are separated
from the marginal carina by a well-marked ante-carinal depression, which appears to
be a little wider in the left valve than in the right. The posterior area bears relative-
ly coarse radial threads. These specimens differ from typical examples of T. brevi-
costata in their slightly coarser ribbing (possibly due to their state of preservation)
and in the tendency of the ribs to swing down posteriorly, but it is quite possible that
they belong to that species. T. brevicostata occurs typically in the Callovian of Cutch,
India, and has been recorded by Stefanini from beds in southern Somalia which seem
to be approximately Callovian in age.

Trigonia elongata J. de C. Sowerby
PIPE, tig 8

1823a. Trigonia elongata J. de C. Sowerby : 39, pl. 431.
1903. Tvigonia chariensis Kitchin : 18, pl. 1, fig. 4; pl. 2, fig. 1.
1952. Tvrigonia elongata Sowerby ; Cox: 109, pl. 12, figs. 3, 4, 7.

MATERIAL. One specimen (no. LL.35109), ex B.P. Coll.

LOCALITY AND HORIZON. About 1} miles W. of Mandawa, Tanganyika ; Callo-
vian(?).

REMARKS. This specimen does not seem distinguishable from English examples
of T. elongata, a species discussed by the present writer in the above-cited work, in
which specimens from the Callovian of Cutch, India, are described. In England its
range extends from the Bathonian to the Oxfordian.

i

FROM TANGANYIKA AND KENYA a

Trigonia migeodi sp. nov.
Plo ies: 1ra, 6

SPECIFIC NAME. After the late F. W. H. Migeod, for some years leader of the
British Museum East Africa Expedition.

DiaGnosis. Small (length of holotype 17-5 mm.), moderately inflated, length
well in excess of height, umbones moderately prominent, marginal carina well
curved ; posterior area broad ; ventral margin rather feebly convex, almost straight
towards its posterior end. Flank ornamented with relatively narrow and numerous,
round-topped concentric ribs separated by intervals of almost the same width ;
number on each valve of holotype estimated at about 30 (those on umbonal region
worn away). Ribs almost reach carina on right valve. The posterior area has a
median groove and bears about 6 radial threads on its antero-ventral side and
probably about the same on its postero-dorsal side, where, however, they are not
well seen.

Hototyre. No. L.51193, a right valve. The only specimen.

LOcALITY AND HORIZON. I mile N.W. of Tendaguru hill, Tanganyika ; Upper
Kimmeridgian, Nerinella Bed.

REMARKS. This specimen differs from T. kidugalloensis in its more elongate out-
line, its more strongly curved marginal carina, and its more closely spaced ribs. It
is quite close to the European Bajocian species 7. hemisphaerica Lycett but has more
closely spaced ribs. It also much resembles 7. tenuis Kitchin (1903 : 35, pl. 3,
figs. 5, 6), from the Upper Jurassic of India (re-named 7. oomia by Strand 1928 : 72),

but it has more closely spaced ribs and a more conspicuous median groove on its

posterior area.

Trigonia dainellii Venzo
Pr, fie: 6
1945. TIvigonia (Lyriodon) dainellit Venzo : 15, figs. Ia—c.
1949. Tvigonia (Lyriodon) dainellii Venzo ; Venzo: 138, pl. 2, figs. 1-5.
)

1949. Tvigonia (Lyriodon) brevicostata Kitchin ; Venzo: 137, pl. 1, figs. 34, 35.
1960. Tvigonia sp. nov. (brevicostata Venzo non Kitchin) ; Joubert, pl. 7, figs. 1a, b.

MATERIAL. Several specimens.

LOCALITIES AND HORIZON. Odda, and W. slope of hill } mile E. of Hafura, both
N.E. Kenya ; Uppermost Jurassic or basal Cretaceous, Danissa Beds.

REMARKS. The general form and the flank ornament of this species are those of a

_ typical costate Trigonia, but there is a tendency for the ribs to undulate irregularly
in later stages of growth. A peculiar feature of the specimens now recorded is that

the ribs of the flank are continued across the marginal carina, some of them bifurcat-
ing at the same time. There is a shallow, linear ante-carinal groove. The posterior
area bears two or three strong radial ribs, and in later stages of growth these are
crossed by transverse ridges.

78 JURASSIC BIVALVIA AND GASTROPODA

The large series of specimens figured by Venzo (1949) as T. brevicostata Kitchin
and as varieties of his new species 7. dainellit seem to present all gradations between
shells in which the flank ribs continue on to the carina, as in the specimens now
recorded, and shells with a smooth ante-carinal area ; this area varies in width and
does not always have a well-defined anterior border. In some specimens included
by Venzo in the forma typica of T. dainellii (e.g. his fig. 3) some of the ribs bifurcate
on the carina, as in the present specimens.

T. dainellii bears a very close resemblance to the European species which has been
well figured by de Loriol (1868 : 160, pl. Io, figs. 12~16 ; pl. 11, fig. 3) under the
name 7. truncata Agassiz. The species in question has a wide range of variation
similar to that of T. dainelli1, and some of its variants have been considered by
Munier-Chalmas (1882 : 498-500) to belong to distinct species to which he has as-
signed names. The specimens from Kenya now recorded are close to de Loriol’s pl.
10, figs. 12, 14, re-named by Munier-Chalmas T. autissiodorensis and T. breom
respectively. The type-specimens of both of these “‘ species ’’ are from the “ Port-
landian ’’’ (probably Upper Kimmeridgian in the British sense) of Auxerre, Yonne,
France. It is possible and even probable that T. dainellit is synonymous with these
European forms, although perhaps not with the true 7. truncata, a species founded by
Agassiz on ill-preserved specimens.

Subgenus FRENGUELLIELLA Leanza 1942

Trigonia (Frenguelliella) tealei Cox
Plex fies 10,

1937b. Trigonia tealei Cox : 201, pl. 16, figs. 2, 3.

MATERIAL. Several specimens, including the holotype (no. L.54113).

LOCALITIES AND HORIZONS. 5S. of Tarawanda, 11 miles S.E. of Lugoba, Tangan-
yika (type-locality) ; Callovian. 2 miles E. of Magindu Station, Central Railway,
Tanganyika ; Callovian. Chinamba, ? mile S. of Amboni quarries, Tanga, Tangan-
yika ; Callovian? (ex B.P. Coll.). Scarp face, eastern margin of Makoko plain,
Bagamoyo hinterland, Tanganyika, also Usigiwa river, 6 miles W.S.W. of Kiwanga,
Bagamoyo hinterland ; Oxfordian.

RemArRKS. The flank ornament of this species resembles that of 7. brevicostata
Kitchin (1903 : 23, pl. 2, figs. 4, 5), from the Callovian of Cutch, India, but the orna-
ment of the posterior area, radial in 7. brevicostata and transverse in T. tealet, en-
ables the two forms to be distinguished.

Subgenus INDOTRIGONIA Dietrich 1933
Trigonia (Indotrigonia) smeei auct.

1914. Tvigonia smeet Sowerby ; Lange : 225, pl. 20, figs. 8-13 ; pl. 21, figs. 1-7.
1933. Tvrigonia (Indotrigonia) smeei Sowerby ; Dietrich : 30, pl. 3, figs. 48-51, 54-56.

FROM TANGANYIKA AND KENYA 79

MATERIAL. Very numerous specimens.

LOCALITIES AND HORIZON. Many localities around Tendaguru, Tanganyika ;
Upper Kimmeridgian.

REMARKS. The trigoniids of the T. smee: group occurring in Tanganyika have
recently been treated exhaustively by Aitken (1961), who considers that they belong
to at least five species, none identical with the true 7. smeez, which occurs in the
Upper Oxfordian of Cutch, India. The name T. (Indotrigonia) africana is assigned
by him (1961 : 75, pl. 8, figs. 2-7 ; pl. 9, figs. 1, 2) to the form most commonly found
at Tendaguru.

Trigonia (Indotrigonia) dietrichi Lange

1914. Tvrigonia dietrichi Lange : 233, pl. 20, fig. 7.
1933. Tvrigonia (Indotrigonia) dietricht Lange ; Dietrich : 32, pl. 2, figs. 38-41.

MATERIAL. Two specimens (nos. L.52640, L.52664).

LOCALITY AND HORIZON. Kindope valley, near Tendaguru, Tanganyika ; Upper
Kimmeridgian, “ Tvigonia smeei”’ Bed.

REMARKS. These specimens, which are imperfect, agree with T. dietrichi as
figured by Dietrich, and show the strong upward bend of the costae as they approach
the marginal carina. This is not a feature indicated in Lange’s original figure, but
his description refers to a slight upward bend of the costae.

Genus MYOPHORELLA Bayle 1878

Myophorella quennelli sp. nov.
PI 12, figs. ra, 6

SPECIFIC NAME. After Mr. A. M. Quennell, formerly Director of the Tanganyika
Geological Survey, collector of the type specimens.

Dracnosis. Of small-medium size (original length of paratype, the larger speci-
men, c. 30 mm.), length only slightly in excess of height ; umbo moderately pro-
minent ; anterior and ventral margins forming a broad curve. Marginal carina
strongly curved ; posterior area broad, forming a wide angle with the flank, and with
an almost vertical posterior margin. Flank ornamented with feebly curved, weakly
tuberculate costae which extend to the marginal carina and slope steeply down from

_ it except in the earlier growth-stages, where they are concentric about the umbo.

The intervals are about twice the width of the costae except in the posterior corner of
the flank, where they are narrower. Two short costae, seen in the holotype but
obscured in the paratype, occupy the space near the anterior margin corresponding
to the change in the curvature of the main costae. Area without sulcus or radial
ribs, but crossed by closely and evenly arranged ridges parallel with posterior
margin.

HOLOTYPE AND PARATYPE. Holotype, no. LL.11809 ; one paratype, no. LL.11810.
Both are left valves.

80 JURASSIC BIVALVIA AND GASTROPODA

LOCALITY AND HORIZON. Just W. of Mabokweni, 4 miles N.W. of Tanga, Tangan-
yika ; Kimmeridgian.

ReMARKS. There is no described Myophorella with which this species could be
confused. In M. kutchensis (Kitchin) (1903 : 84, pl. 8, figs. 7-9) the umbo is less
prominent and the costae are broken up into irregularly distributed tubercles on the
anterior part of the flank.

Myophorella kiwawaensis sp. nov.
Pil 312, fies. 22, 0

DiaGnosis. Small, ovate, almost orbicular, length (c. 16 mm.) only slightly
exceeding height. Umbones not prominent, at anterior third of length. Anterior
and ventral margins forming an even curve of strong convexity ; posterior margin
relatively long, erect. Marginal carina gently curved, obtusely angular, nodose ;
escutcheon carina nodose. Posterior area short, moderately broad, without median
groove, and bearing closely arranged transverse threads. Flank with rather deli-
cate nodose costae, those near posterior end straight and vertical, middle ones well
curved.

HOLOTYPE AND PARATYPES. Holotype, no. LL.35110, also three paratypes,
including no. LL.35111 ; all ex B.P. Coll.

LOCALITY AND HORIZON. Kiwawa stream, 2400 yards S.E. of Mitekera survey
beacon, northern Mandawa area, Tanganyika ; Upper Kimmeridgian.

REMARKS. The absence of a radial groove on the posterior area distinguishes this
species from young specimens of Myophorella striata (Miller) and of related Inferior
Oolite species.

Genus LAEVITRIGONIA Lebkichner 1932

Laevitrigonia dwanikana sp. nov.
Plrazg ie.S

DiaGnosis. Shell of medium size (length 35 mm.), ovate, rounded posteriorly ;
length not greatly exceeding height. Umbo not prominent, situated at about
anterior third of length ; ventral margin strongly and symmetrically convex.
Marginal carina an obscure ridge ; posterior area convex, forming a wide angle with
the flank ; no ante-carinal depression. Anterior part of flank ornamented with
broad, depressed rounded ribs, some split up into irregular nodes by transverse
furrows, separated by much narrower intervals. In earlier stages of growth the
ribs bend up to the marginal carina, but in later stages they end half-way to the
carina, leaving the rest of the flank smooth. Posterior area apparently without
ornament (but rather eroded in holotype).

HototyPe. No. L.52692 ; the only specimen.

LocaLITy AND HORIZON. Dwanika river, Tendaguru, Tanganyika ; Upper
Kimmeridgian, “‘ Tvigonia smeei’’ Bed.

FROM TANGANYIKA AND KENYA 81

REMARKS. This is a very typical Laevitrigonia, differing from the type-species,
L. gibbosa (J. Sowerby), in the absence of an ante-carinal depression, but comparable
to some other species from the Upper Jurassic of Europe, for example, L. acteon
(Munier-Chalmas) (1882 : 503, pl. 12, fig. 5) and L. owstalet: (Munier-Chalmas) (1882 :
503, pl. 12, fig. 7). It differs from previously known species in details of ornament.

Genus RUTITRIGONIA Van Hoepen 1929

Rutitrigonia stefaninii (Venzo)
Pl. 12, figs. 3a, 6
1942a. Trigonia (Laevitrigonia) stefaninii Venzo : 27, fig. 10.
1949. Trigonia (Laevitrigonia) stefaninii Venzo ; Venzo: 145, pl. 2, figs. 28-33 ; also figs.
34-50 (varieties).
1960. Trvigonia stefaninii Venzo ; Joubert, pl. 7, figs. 2a, b.

MATERIAL. Two specimens (nos. L.g2180, L.g2273).

LOCALITIES AND HORIZON. 3 miles N.E. of Melka Dakacha, N.E. Kenya, and 2
miles S. of Melka Dakacha ; Upper Kimmeridgian, Dakacha Limestones.

REMARKS. The better preserved specimen, now figured, is a trigonally ovate
shell in which the posterior carina fades away after an early stage of growth and the
weak, undulating ribs are confined to the anterior end of the flank. It is closely com-
parable to some of Venzo’s figures. This is obviously a variable species and the
_ numerous varietal names introduced by Venzo seem unnecessary.
_ This species is of some interest as it appears to belong to the genus Rutitrigonia,
_ hitherto known only from Cretaceous rocks. Its umbo is rather more prominent
_ than in the more typical representatives of the genus, but the fading away of its
| narrow, undulating flank costae on the posterior part of the flank, its smooth poste-
rior area, and its ill-defined marginal carina are exactly as in such species as R.
| excentrica (Parkinson) (figured Lycett, 1875 : 94, pl. 20, figs. 5,6; pl. 21, figs. 6, 7 ;
| pl. 22, figs. 5, 5a) and R. laeviuscula (Lycett) (1875 : 96, pl. 22, fig. 6).

Genus OPISTHOTRIGONIA Cox 1952
Opisthotrigonia curta (Aitken)
Pl. 12, fig, 4
1961. Laevitrigonia curta Aitken : 97, pl. 14, figs. 1-3.

MATERIAL. Two specimens (including no. LL.35112), ex B.P. Coll.

LOCALITY AND HORIZON. Mpilepile stream, 800 yards E.N.E. of junction of main
_road and Mahokondo road, Mitole, northern Mandawa area, Tanganyika ; Upper
_ Kimmeridgian.

Remarks. Prior to the publication of Aitken’s paper, these specimens had been
| described in MS. as a new species of Opisthotrigonia. One which is 43 mm. long and
considerably larger than any of Aitken’s specimens is here figured to illustrate the

82 JURASSIC BIVALVIA AND GASTROPODA

relative size of the depressed ante-carinal space in the right valve. Except in very
early growth stages the rather irregular ribs cross this space and terminate at or very
close to the blunt marginal carina. The species appears to be more closely related
to the typical species of Opisthotrigonia than to Laevitrigonia.

Superfamily MODIOMORPHACEA
Family HIPPOPODIIDAE nov.
Genus HIPPOPODIUM J. Sowerby 1819
Hippopodium quenstedti (Dietrich)
1933. Epihippopodium quenstedti Dietrich : 71, pl. 9, fig. 136; pl. 10, figs. 142, 143.

MATERIAL. Six specimens.

LOCALITIES AND HORIZONS. I mile N.W. of Tendaguru hill, Tanganyika ; Upper
Kimmeridgian, Nerinella Bed. Kindope road, Tingutitinguti creek, and 14 miles
N.N.W. of Tapaira, all near Tendaguru, Tanganyika ; Upper Kimmeridgian,
“ Trigonia smeei’”’ Bed.

Remarks. Although Dietrich founded a genus Epihippopodium on this species,
comparison of his figures showing the internal characters of the shell and of the
present specimens with examples of Hippopodium ponderosum J. Sowerby, the
Lower Liassic type-species of Hippopodium, shows such close agreement in all
essential characters that the generic separation of the Tendaguru form seems un-
justified. H. quenstedti differs from H. ponderosum only in its larger size and its
broader form. It would thus seem that Hippopodium lingered on in some remote
area after its disappearance from N.W. Europe at the close of the Middle Lias, to re-
appear almost at the top of the Jurassic in East Africa.

Superfamily CRASSATELLACEA
Family ASTARTIDAE d Orbigny 1844
Genus ASTARTE J. Sowerby 1816

Astarte lurida J. Sowerby
Pl a2 ire.

1816a. Astarte lurida J. Sowerby : 81, pl. 137, fig. 1.

1836. Astarte subtetvagona Miinster [previously nom. nud.] ; Roemer: 113.

1837. Astarte excavata Sow. ; Goldfuss : 190, pl. 134, figs. 6c, d (non a, b) (non J. Sowerby).
1837. Astarte subcarinata Miinster in Goldfuss : 190, pl. 134, figs. 7a, b.

1840. Astarte subtetragona Minster ; Goldfuss : 304 (Verbesserung, for pl. 134, figs. 6c, d.).
1842. Astarte subtetragona Miinster ; Roemer : 13.

1853. Astarte subtetragona Minster ; Chapuis & Dewalque : 150, pl. 22, fig. 4.

1869. Astarte subltetvragona Minster ; Brauns: 226.

1874. Astarte subtetragona Minster ; Dumortier : 176, pl. 40, figs. 5, 6.

FROM TANGANYIKA AND KENYA 83

1874. ?Astarte luvida Sow. ; Dumortier : 175, pl. 40, figs. 2-4.

1905. Astarte elegans Sow. ; Benecke: 214, pl. 16, figs. 1-3 (non J. Sowerby).

1923. Astarte sublaevis d’Orbigny ; Ernst: 67, pl. 1, figs: 13a, b only (non d’Orbigny).

1935. Astarte subtetragona Miinster (with vars. brevis, krumbecki and subcarinata) ; Kuhn :
123, pl. 8, figs. 39a, b ; pl. 9, figs. 17a, b, 20a, b, 28a, b ; pl. 10, figs. 20a, b.

MATERIAL. One specimen (no. LL.35044).

LOCALITY AND HORIZON. Didimtu hill, 2 miles S. of Bur Mayo, N.E. Kenya ;
Upper Lias, Toarcian, Didimtu Beds.

REMARKS. Sowerby’s holotype of Astarte lurida (B.M. (N.H.) no. 43082), from
the neighbourhood of Naunton, Gloucestershire, belongs to a widely distributed
Upper Liassic species. Abundant specimens from the Cotswold Cephalopod Bed
(Yeovilian) illustrate the variability of the species. There is complete intergrada-
tion between ovate shells in which the umbo is not terminal and the postero-dorsal
and posterior margins meet in a broad curve, and shells with a rectangular to rhom-
boidal outline in which the umbo is terminal and the margins mentioned meet in a
well-defined right or obtuse angle. There is also considerable variation in ornament,
some specimens having fairly regular concentric ribs and others irregular rugae.
These observations have led to the conclusion that A. subtetragona, based on rhom-
boidal specimens, should be regarded as a synonym of A. lurida.

The specimen now recorded is 38:5 mm. long and thus of about the same size as
many specimens from the Cotswold Cephalopod Bed. Like the holotype, it is a
relatively ovate representative of the species. In England this species ranges from
the bifrons Zone of the Whitbian stage of the Upper Lias to the sczsswm Zone, near
the base of the Inferior Oolite.

Astarte pulfreyi sp. nov.
Pl. 12, figs. r2a, b, 13

SPECIFIC NAME. After Dr. W. Pulfrey, lately Director of the Kenya Mines and
Geological Department.

Diacnosis. Of large-medium size (length of largest specimen c. 33 mm.), sub-
orbicular with a quadrate tendency, length very slightly exceeding height, moderately
inequilateral ; inflation weak. Umbones at about anterior third of length, not
incurved, directed anteriorly, their outline continuous with postero-dorsal outline,
which is feebly convex and gently inclined, joining the feebly convex, subvertical
posterior margin in an even curve or forming a rounded-off, obtuse angle with it ;
antero-dorsal outline feebly concave near umbo, steeply sloping ; anterior margin
rather strongly convex ; ventral margin strongly convex anteriorly, less convex
posteriorly, where it forms a rounded-off, obtuse angle with posterior margin.
Escutcheon and lunule narrow and shallow, almost absent. No ornament except
growth-rugae. Valve-margins denticulate internally.

HOLOTYPE AND PARATYPES. Holotype, no. LL.35027 ; 4 paratypes.

LocaLiTy AND HORIZON. Didimtu hill, 2 miles S. of Bur Mayo, N.E. Kenya ;
Upper Lias, Toarcian, Didimtu Beds.

84 JURASSIC BIVALVIA AND GASTROPODA

REMARKS. The hinge-teeth are not seen in any of the specimens but there is
little doubt that the species is an Astarte. It is more quadrate in outline and less
strongly inequilateral than A. lurida, recorded above. A. camertonensis Moore
(1867 : 213, pl. 7, fig. 21), from the Pliensbachian of England, is more elongate.

Astarte didimtuensis sp. nov.
Pl, 12; figs. 10a)-0;<eprna; 6,06

DiaGnosis. Small (length of largest specimen c. 12:5 mm.), ovate, inequilateral ;
height three-quarters to four-fifths of length, beaks from anterior fifth to quarter of
length ; inflation moderate. Umbones subangular, not incurved, prosogyrous ;
postero-dorsal outline straight, subhorizontal, meeting the strongly convex posterior
margin in an even curve which is continued by the strongly convex ventral and
anterior margins ; antero-dorsal outline strongly concave. Lunule moderately
impressed ; escutcheon narrow and shallow. Ornament consisting of fine, equal
concentric riblets which may show slight irregular undulations on posterior part of
surface.

HOLOTYPE AND PARATYPES. Holotype, no. LL.35032 ; 9 paratypes.

LOCALITY AND HORIZON. Didimtu hill, 2 miles S. of Bur Mayo, N.E. Kenya ;
Upper Lias, Toarcian, Didimtu Beds.

REMARKS. Astarte didimtuensis is more elongate and has finer concentric orna-
ment than its associated species A. subminima, described below. It is quite unlike
A. voltzii Roemer (1836: 112, pl. 7, fig. 17), the common small astartid of the
European Upper Lias, differing in its more elongate and much more compressed
form and in the even distribution and fineness of its concentric threads.

Astarte subminima sp. nov.
Pl. 12, figs. 14a, b

DiaGnosis. Small (length c. 6 mm.), subtrigonal with an orbicular tendency,
inequilateral ; height and length almost equal ; beak at about anterior quarter of
length ; inflation weak. Umbo sharply rounded in outline, not incurved, slightly
prosogyrous ; postero-dorsal outline slightly convex, gently sloping, forming a well-
marked, obtuse angle with the rather low, straight, subvertical posterior margin ;
ventral margin strongly convex, meeting posterior margin in an ill-defined, obtuse
angle ; anterior margin low ; antero-dorsal outline concave, steep. Lunule
moderately impressed, no escutcheon. Ornament consisting of fine, equal con-
centric ribs. Ventral margin denticulate internally.

HototyPe. No. LL.35042. The only specimen.

LOCALITY AND HORIZON. Didimtu hill, 2 miles S. of Bur Mayo, N.E. Kenya ;
Upper Lias, Toarcian, Didimtu Beds.

REMARKS, This species is rather similar to Astarte minima Phillips, from the

FROM TANGANYIKA AND KENYA 85

Bajocian of Europe, but is more finely ribbed and less rectangular in outline. A.
depressa Goldfuss, a Bajocian species well figured by Cossmann (1913a@ : 9, pl. 3,
figs. 18-27), is more trigonal in outline. <A. gillieront Mayer (1875 : 234, pl. Io,
fig. 4), Upper Lias of Switzerland, is a larger form with a more strongly prosogyrous
umbo.

Astarte sp.
Pl: 12) figssa5a) 6

MATERIAL. One specimen (no. LL.35043), defective postero-ventrally.

LocALITY AND HORIZON. Didimtu hill, 2 miles S. of Bur Mayo, N.E. Kenya ;
Upper Lias, Toarcian, Didimtu Beds.

DESCRIPTION. Small (length when complete c. 7-5 mm.), suborbicular, with a tri-
gonal tendency, inequilateral ; height and length almost equal, beaks at anterior
fifth of length ; inflation moderately strong. Umbo rather broadly rounded, well
incurved ; postero-dorsal outline moderately convex and sloping, forming a rounded-
off, obtuse angle with the low, almost straight, subvertical posterior margin ; ventral
margin rather strongly convex ; antero-dorsal outline very feebly concave, steeply
sloping ; anterior margin low. Lunule (rather obscured in this single specimen)
moderately impressed ; presence of escutcheon doubtful. Ornament consisting of
fine, equal concentric riblets.

REMARKS. This form is more gibbose than A. swbminima and has rather stronger
concentric riblets, but the single specimen seems too imperfect to serve as the type
of a new species.

Astarte kenti sp. nov.
Plo12 fies: 6a, 6, 7a, 6

SPECIFIC NAME. After Dr. P. E. Kent, of the British Petroleum Co., Ltd.

DiaGnosis. Small (maximum length c. 15 mm.), trigonally ovate, height two-
thirds to three-quarters of length ; inequilateral, beaks from anterior quarter to
third of length ; inflation weak. Umbones obtusely angular, not incurved, mode-
rately prominent ; postero-dorsal outline convex, gently sloping, antero-dorsal
outline almost straight, steeply sloping ; lunule absent or ill-defined ; escutcheon, if
distinguishable, narrow and limited by ill-defined umbonal ridges. Posterior margin
feebly convex, varying in height and inclination ; ventral margin flat to feebly con-
vex. Early growth-stages ornamented with regular, close-spaced concentric ridges,
later stages with rather irregular concentric undulations and rugae. Valve margins
denticulate internally.

HOLOTYPE AND PARATYPES. Holotype, no. LL.35113 ; about 18 paratypes.

LOCALITY AND HORIZON. Near site of Mandawa well no. 1, Tanganyika ; Bajo-
cian(?).

REMARKS. The most closely described Bajocian species is Astarte hauthali Wetzel
(IgII : 249, pl. 20, figs. Ig, 20), which is slightly more rectangular.

86 JURASSIC BIVALVIA AND GASTROPODA

Astarte pindiroensis sp. nov.
Pl. 13, figs. 4a, b, 5a, b

DiaGnosis. Small (length of holotype 5:5 mm ; of largest paratype II mm.),
rectangularly ovate, height from four-fifths to five-sixths of length, inflation mode-
rate. Inequilateral, umbones situated from anterior quarter to third of length,
scarcely incurved, directed anteriorly, their outline continuous with the feebly con-
vex, gently sloping to sub-horizontal postero-dorsal outline of the shell, which merges
in a broad curve with the feebly convex, only slightly oblique posterior margin ;
ventral margin moderately convex, forming a rounded-off, obtuse angle with poste-
rior margin and merging in an even curve with the broadly convex anterior margin ;
concavity of antero-dorsal outline confined to neighbourhood of beak. No diagonal
ridge. Escutcheon very narrow, bordered by blunt umbonal ridges ; lunule an un-
impressed cordiform area limited by faint striae. Ornament consisting of fine con-
centric threads, slightly unequal and irregularly arranged in places.

HOLOTYPE AND PARATYPES. Holotype, no. LL.35206, figured paratype, no.
LL.35207, both extracted from a piece of limestone containing a large number of
other paratypes.

LOCALITY AND HORIZON. Tributary of Namakumbira stream, 1 mile S.E. of
Nkomore, Mandawa-Mahokondo area, Tanganyika ; Bajocian (?), Pindiro Shales.

REMARKS. This species is smaller and less trigonal than A. kenti, described above.

Its very fine ornament distinguishes it from the European Bajocian form A. minima
Phillips.

Astarte ayersi sp. nov.
P].. 03, sfigs.-74, 6

SPECIFIC NAME. After Mr. F. M. Ayers, of the Kenya Geological Survey.

DiaGnosis. Rather small (length of holotype 15 mm.), triangularly subovate,
slightly longer than high, evenly and fairly strongly inflated. Umbo prominent,
narrowly rounded in outline, placed at about anterior third of length. Antero-
dorsal outline slightly convex, sloping gently, and forming a rounded-off, obtuse
angle with posterior margin ; posterior, ventral and anterior margins forming an
even curve which is almost a semicircle : antero-dorsal outline strongly excavated.
Ornament consisting of narrow, evenly spaced concentric ridges about 0-75 mm.
apart in later growth-stages.

HOLOTYPE AND PARATYPES. Holotype, no. L.83876 ; numerous paratypes,
mainly imperfect.

LOCALITY AND HORIZON. 1 mile N. of Asaharbito, N.E. Kenya ; Bathonian [? or
Callovian|, Asaharbito Beds.

REMARKS. This species bears some resemblance to the European Bathonian
species A starte oolitharum Cossmann (1925 : 663, pl. 22, figs. 14, 15) (= A. depressa
Morris & Lycett 1855, pl. 9, fig. 11, non Goldfuss), but is considerably larger. The

FROM TANGANYIKA AND KENYA ; 87

species Astarte daphne de Loriol (1891 : 244, pl. 26, figs. 25-27), Upper Oxfordian of
Switzerland, is comparable in size and shape, but its concentric ribs are more closely
spaced.

Astarte muelleri Dacqué

1900. Astarte sp ; Miiller : 534, pl. 17, fig. 7.
1910. Astarte miilleri Dacqué : 31, pl. 4, fig. 5.
19376. Astarte miilleri Dacqué ; Cox: 202.

MATERIAL. One specimen (no. L.54117).

LOCALITIES AND HORIZONS. 2 miles E. of Magindu Station, Central Railway,
Tanganyika ; Callovian. Miller’s original specimen came from a locality 1-5 km.
W. of the Mahokondo stream, 24:5 km. N.W. of Kiswere, where the beds are now
thought to be Callovian in age.

Astarte aitkeni sp. nov.
Pir, tes. 04,0; ¢

SPECIFIC NAME. After Dr. W. G. Aitken, lately Director of the Geological Survey
of Nyasaland, collector of the holotype.

Diacnosis. Rather small (length of holotype 12 mm.), trigonally orbicular,
slightly higher than long, compressed, early growth-stages flattened. Umbones just
anterior to median, obtusely angular. Postero-dorsal outline strongly convex, steep,
meeting almost semicircular ventral margin in an ill-defined angle ; anterior outline
very feebly convex, steep. Escutcheon narrow, no lunule. Surface, up to mid-
growth, bearing obtusely angular ridges, widely separated except near umbo, the
last two 3 mm. apart ; later growth-stages bearing only rather fine concentric
threads.

HototyrPe. No. LL.35189. The only specimen.

LOCALITY AND HORIZON. Nchia stream, 2 miles W.N.W. of Mandawa, Tangan-
yika ; Callovian.

REMARKS. This species differs from A. huralensis Stefanini, recorded below (p. 89),
in its taller form, in the wider spacing of its obtuse concentric ridges, and in the ab-
sence of such ridges in later stages of growth.

Astarte unilateralis J. de C. Sowerby
Pl. 14, figs. 2, 3

1840b. Astarte unilateralis J. de C. Sowerby : 327, pl. 21, fig. 14.

1863. Astarte hermanni Oppel : 272.

1865. Astarte unilateralis Sow. ; Salter in Strachey : 97, pl. 23, fig. 10.
1913. Astarte hermanni Oppel ; Holdhaus : 440, pl. 99, figs. 7-11, 14.

MATERIAL. Two specimens (nos. LL.35118—109), ex B.P. Coll.
LOCALITY AND HORIZON. Lonji creek, W. of Mandawa, Tanganyika ; Callovian?

88 JURASSIC BIVALVIA AND GASTROPODA

REMARKS. Specimens of this species from the Spiti Shales were described very
fully by Holdhaus, but it is not clear why he preferred Oppel’s specific name to the
earlier one of Sowerby. Sowerby’s type and the specimen from the Spiti Shales
figured by Salter are both in the British Museum (Natural History), where there are
also numerous topotypes from Cutch. The species is characterized by its strongly
inequilateral cuneiform shape and its strongly convex postero-dorsal outline, which in
many specimens rises appreciably above the umbo before beginning to slope steeply
downwards to join the low posterior margin in an uninterrupted curve. The
earlier growth stages are ornamented with well separated, regular, angular concentric
folds, which later are replaced by irregular rugae. This is the first record of the spe-
cies from East Africa. The specimens recorded are up to about 44 mm. long and
quite typical as regards shape and ornament.

In Cutch this species occurs most commonly in the Callovian athleta Beds and
Oxfordian Dhosa Oolite. Ill-preserved specimens which appear to be referable to it
occur in the Callovian Chari beds and also in the Upper Oxfordian.

Astarte sowerbyana Holdhaus
Pl. 13, figs. 6a, b

1840c. Astarte major J. de C. Sowerby, pl. 61, fig. 1 and explan. (non Astarte elegans major
Zieten).

1913. aisten sowerbyana Holdhaus : 443, pl. 99, figs. 12, 13, 15 ; pl. 100, fig. 1.

1933. Astarte kvenkeli Dietrich : 40, pl. 4, figs. 62, 64, 66.

MATERIAL. Three specimens (including nos. L.52688, LL.35120), partly ex B.P.
Coll.

LOCALITIES AND HORIZONS. Lihimaliao creek, Mandawa area, Tanganyika ;
Upper Oxfordian. N. of Kipande, also 1 mile N.W. of Tendaguru hill, Tanganyika ;
Upper Kimmeridgian, Nerinella Bed.

REMARKS. This species differs from A. wnilateralis in its more ovate outline and
larger size, although the difference in size is not so marked in the specimens from
the Spiti Shales described by Holdhaus as in those from India and East Africa. In
the African specimens, as in those from India, there is some variation in the relative
elongation of the shell. Sowerby’s type specimen of A. major, which is in the British
Museum (Natural History), is a relatively elongate shell and very similar to Dietrich’s
type of A. krenkeli: It is strange that Dietrich made no reference to Sowerby’s
species. In early stages of growth A. sowerbyana, like A. unilateralis, bears con-
centric folds. In later stages these are replaced by rather distant concentric undula-
tions in some specimens and by irregular corrugations in others.

In Cutch this species occurs at several localities in the Upper Oxfordian (Argovian)
Astarte Bed, and it reappears in the Tithonian of Moondan and elsewhere.

Astarte episcopalis de Loriol

1897. Astarte duboisi d’Orbigny ; de Loriol: 88, pl. 12, fig. 13 (non d’Orbigny).
1901. Astarte episcopalis de Loriol : 72, pl. 5, figs. 1, 2.

FROM TANGANYIKA AND KENYA 89

MATERIAL. Four specimens (nos. LL.16837—40).

LOCALITY AND HORIZON. Usigiwa river, 6 miles W.S.W. of Kiwangwa, Baga-
moyo hinterland, Tanganyika ; Upper Oxfordian.

REMARKS. The length of the largest specimen referred to this species is 72 mm.
The shell is ovate, with the height equal to about three-quarters of the length, and
is strongly inequilateral and of moderate and even convexity. The umbo is slightly
obtuse and not quite terminal. The postero-dorsal outline is of moderate convexity,
rising at first to a level slightly above that of the umbo, and then sloping down to
form a rounded-off, obtuse angle with the slightly oblique and flattened posterior
margin ; the antero-dorsal outline is scarcely excavated. The ventral and antero-
ventral margins are of strong convexity. The lunule is shallow and there is no
escutcheon. The surface bears concentric undulations, which are regular in early
stages of growth, but later become very irregular.

The African specimens do not appear to differ in any features of importance from
A. episcopalis which occurs typically in the “ Middle Oxfordian’”’ of the Bernese
Jura. Of the other species now recorded from East Africa, A. muelleri Dacqué is
more trigonal in outline. A. swbobovata Dietrich is more rounded posteriorly and
less elongate, A. vecki Dietrich has a more strongly convex postero-dorsal outline,
and A. mitoleensis sp. nov. is more elongate and tapers more towards its posterior
end.

Astarte huralensis Stefanini
Phy t5; figsan

1939. Astarte huralensis Stefanini : 234, pl. 24, figs. 19, 20a—c.
1960. Astarte sp. nov. ; Joubert, pl. 9, figs. 4a, b.

MATERIAL. Numerous specimens (nos. L.g2123, L.g2236—39), preserved on the
surface of blocks of limestone.

LOCALITY AND HORIZON. Dussé, 1} miles S.E. of Rahmu, N.E. Kenya ; Upper
Oxfordian, Seir Limestones.

REMARKS. The specimens now recorded agree well in size and ornament with
Stefanini’s figures, which do not, unfortunately, show the outline of the shell very
clearly. The Kenya specimens are up to about 9 mm. in length, rectangularly ovate
to subtrigonal, with the length slightly exceeding the height, and not strongly in-
_ flated. The umbo, which is obtusely angular and not incurved, is not quite terminal,
the anterior margin of the shell projecting slightly beyond it. The dorsal margin is
' convex, meeting the nearly straight and vertical posterior margin in a rounded-off,
obtuse angle. The ventral margin is strongly convex and the antero-dorsal outline
_ is moderately excavated below the beak. The ornament consists of relatively wide-
spaced, obtusely angular concentric ridges, the crests of which are about 1-8 mm.
apart ; no subordinate threads are present.

The most closely comparable European species appears to be Astarte cingulata
_ Contejean (1860 : 267, pl. 11, figs. 5-10), from the Kimmeridgian, in which the out-
line of the shell is more trigonal. A. huralensis was described originally from the
“ Oolitico medio” (? Oxfordian) of southern Somalia.

90 JURASSIC BIVALVIA AND GASTROPODA

Astarte mandawaensis sp. nov.
Pl. 14, figs. 6a, b

DiaGnosis. Of medium size (length of holotype 38 mm.), ovate, rather strongly
inequilateral, length exceeding height, beak at anterior third of length ; shell well
inflated for the genus. Umbo obtusely angular, depressed, slightly incurved to
prosogyrous beak. Postero-dorsal outline rather strongly convex, level with umbo
anteriorly, down-curved posteriorly, where it forms an obtuse angle with the some-
what flattened posterior margin ; ventral and anterior margins forming an uninter-
rupted curve of strong convexity ; antero-dorsal outline strongly concave. Lunule
broad, flattened and deep, bordered by well-defined ridge ; escutcheon narrow.
Ornament of irregular concentric undulations which are broad and relatively few on
anterior two-thirds of surface but increase in number by intercalation or bifurcation
on posterior part, where they are consequently of diminished width.

Anterior cardinal tooth of left valve stout and prominent, sloping back from beak
and separated by narrow space from lunular margin ; posterior cardinal tooth
elongate, slightly curved, forming very acute angle with ligamental nymph.

HototyPe. No. LL.35121, ex B.P. Coll. The only specimen.

LOCALITY AND HORIZON. Lonji creek, W. of Mandawa, Tanganyika ; Upper
Kimmeridgian.

REMARKS. Although the postero-ventral part of the holotype is broken away,
the well inflated, ovate form of the shell is very distinctive for an astartid, while the
ornament is also characteristic. It differs from the approximately contemporaneous
East African species A. weissermeli Dietrich, recorded below (p. 92), in its more
elongate outline, its broader and more unevenly arranged concentric undulations,
and its deep, distinctly bordered lunule.

Astarte lonjiensis sp. nov.
Pl a4 ie. 2

DiacGnosis. Large (length of holotype 74 mm.), ovate with slight trigonal tendency,
highly inequilateral, height six-sevenths of length ; inflation rather weak. Umbo
almost terminal, slightly incurved, rather sharply rounded in outline ; postero-
dorsal outline continuous with that of umbo, at first convex and rising very slightly
above level of latter, but almost straight and sloping gently downwards along greater
part of length ; it forms a slightly obtuse angle with the short, straight, subvertical
posterior margin. Antero-dorsal outline steep, slightly concave ; ventral margin
very strongly convex. Lunule narrow, moderately excavated ; no escutcheon.
Early growth-stages ornamented with regular, rather closely spaced concentric ribs,
which in later stages are replaced by coarse, irregular rugae. Interior not exposed.

HoLotyPe. No. LL.35122, ex B.P. Coll. The only specimen.

LOCALITY AND HORIZON. Lonji creek, W. of Mandawa, Tanganyika ; Upper
Kimmeridgian.

FROM TANGANYIKA AND KENYA 9!

REMARKS. This species is less tumid than A. sowerbyana, has a more strongly
convex ventral margin, and is more closely ribbed on its umbonal region. It is less
orbicular in shape than A. recki Dietrich, which is abundant in the Upper
Jurassic at Tendaguru.

Astarte subobovata Dietrich
Pl. 15, fig. 4
1933. Astarte subobovata Dietrich : 40, pl. 5, figs. 68, 74 ; pl. 9, fig. 141.

MATERIAL. One specimen (no. L.52683).

LOCALITY AND HORIZON. Maimbwi river, Tendaguru, Tanganyika ; Upper
Kimmeridgian, “ Tvigonia smeei”’ Bed.

REMARKS. Dietrich’s two figured syntypes showing the exterior of the shell
(pl. 5, fig. 68 ; pl. 9, fig. 141) differ considerably in shape. A study of the figures
suggests, however, that the distinction between this species and the closely com-
parable species A. vecki lies mainly in the broadness of the concentric folds on the
main part of the surface, which rather resemble those of a Cardinia. Other points
of distinction are the less strongly convex postero-dorsal margin and the stronger
inflation of the shell, especially in the umbonal region. On the basis of such differ-
ences, a single specimen in the material studied is assigned to A. subobovata.

It is not clear why Dietrich not only commented on the similarity between this
species and the Lower Cretaceous species A. obovata J. de C. Sowerby but also as-
signed a specific name to it suggesting affinity with the form in question. In 4A.
obovata the concentric folds on the main part of the surface of the shell are of much
smaller amplitude than in A. swbobovata and not in the least reminiscent of those of
a Cardinia.

Astarte recki Dietrich
Pl. 14, figs. 4, 5
1933. Astarte vecki Dietrich : 40, pl. 4, fig. 60 ; pl. 5, figs. 69-71.

MATERIAL. Several specimens.

LOCALITIES AND HORIZONS. Several localities around Tendaguru, Tanganyika ;
Upper Kimmeridgian, Nerinella and “ Trigonia smeei’’ Beds.

Remarks. A particular characteristic of this large species is the broad convexity
(almost an obtuse angularity) of the anterior part of the postero-dorsal margin, which
rises well above the level of the beak. The length of the shell exceeds the height very
_ slightly and the anterior margin projects beyond the beak to a variable extent, but
usually not very much. In most specimens the posterior margin is a little flattened,
but in some it is convex and merges with the ventral margin in an even curve. Up
to a height of 25 mm. the shell bears closely and regularly spaced concentric ridges,
_ but in later growth-stages these are replaced by irregular rugae and corrugations.
_ The length of the largest specimen examined is about 90 mm.

92 JURASSIC BIVALVIA AND GASTROPODA

Astarte weissermeli Dietrich
Pl) 18, fiese 25 3

1933. Astarte weissermeli Dietrich : 41, pl. 6, figs. 75-80.

MATERIAL. Several specimens.

LOCALITIES AND HORIZONS. Nitongola creek, Maimbwi river, Kindope valley,
and ? mile S. of Nautope, all Tendaguru district, Tanganyika ; Upper Kimmeridgian,
“ Trigonia smeet”’ Bed. Mpilepile stream, 800 yards E.N.E. of junction of main
road and Mahokondo road, Mitole, northern Mandawa area, Tanganyika ; Upper
Kimmeridgian.

ReMARKS. This is a fairly strongly and evenly inflated, suborbicular species with
a rather prominent umbo situated at about the anterior third of the length of the
shell and with ornament of strong, irregular concentric corrugations. The largest
specimen in the material studied is about 30 mm. high.

Astarte mitoleensis sp. nov.
Pir) fies

Diacnosis. Large (length of holotype 74 mm.), ovate, height four-fifths of length,
strongly inequilateral ; inflation moderate. Umbo not quite terminal, incurved,
convexly subangular in outline ; postero-dorsal outline strongly convex, rising at first
well above umbo and then curving down to form a rounded-off, obtuse angle with
the rather low, almost straight, vertical posterior margin. Antero-dorsal outline
strongly excavated ; ventral and antero-ventral margins of moderately strong
convexity. Lunule well excavated ; noescutcheon. Median part of flank flattened
ventrally. Ornament consisting of very irregular concentric undulations and rugae,
not more evenly arranged in early than in later growth-stages.

HoLotyPe. No. LL.35123, ex B.P. Coll. The only specimen.

LOCALITY AND HORIZON. Mpilepile stream, 1300 yards E.N.E. of Mitole road
junction, northern Mandawa area, Tanganyika ; Upper Kimmeridgian.

REMARKS. This species differs from Astarte stuhlmanni (Miller), Neocomian,
Tanganyika, and from A. subobovata Dietrich, Upper Kimmeridgian, Tanganyika,
in its less inflated form, its more strongly excavated antero-dorsal outline, and its flat
posterior margin. Compared with A. episcopalis de Loriol, it is higher at its poste-
rior end and less elongate. It very closely resembles the European Aptian species
Astarte obovata J. Sowerby.

Subgenus LECKHAMPTONIA Cox & Arkell 1948

Astarte (Leckhamptonia) hobleyi sp. nov.
Pl. 15, figs. 2a, b

SPECIFIC NAME. After the late C. W. Hobley, a pioneer in the investigation of
the geology of Kenya.

FROM TANGANYIKA AND KENYA 93

Diacnosis. Of medium size (length of larger specimen c. 30 mm.), rectangular,
height two-thirds of length, beaks at about anterior third of length ; inflation slight.
Umbo very broad, not incurved ; postero-dorsal outline straight, horizontal, form-
ing a slightly obtuse angle with the straight or feebly convex posterior margin ; ven-
tral margin straight, parallel with postero-dorsal outline ; antero-dorsal outline very
slightly concave, gently inclined ; anterior margin of feeble convexity. Ornament
consisting of almost equidistant, well separated, erect lamellae, with fine growth-
threads in their intervals.

HOLOTYPE AND PARATYPE. Holotype, no. LL.35045. One paratype only, no.
LL.35046.

LOCALITY AND HORIZON. Didimtu hill, 2 miles S. of Bur Mayo, N.E. Kenya ;
Upper Lias, Toarcian, Didimtu Beds.

REMARKS. This species seems closely related to Astarte (Leckhamptonia) inter-
lineata Morris & Lycett, of the Bajocian and Bathonian of England, but it is much
larger. It bears some resemblance to the internal mould from the Upper Lias of
Germany figured by Roemer (1836 : 120, pl. 8, fig. 3) as “Corbis laevis Sow.?’”’ and
re-named Astarte sublaevis by d’Orbigny.

Genus COE LASTARTE Boehm 1893

Coelastarte dietrichi sp. nov.

1933. Astarte (Coelastarte) cf. cotteausia (d’Orb.) de Loriol ; Dietrich : 42, pl. 4, fig. 61 (non
A. cotteausia d’Orbigny).

DiaGnosis. Shell of medium size (length of holotype c. 40 mm.), rectangularly
ovate, well elongated (length to height ratio 5 : 3), compressed. Beaks at about
anterior fifth of length, pointed, directed downward to some extent, with convex
dorsal margin rising above them ; antero-dorsal outline concave. Posterior margin
rounded except in earlier stages of growth, ventral margin flattened. Concentric
undulations strong and regular in earlier stages of growth, bending upward in a well-
defined angle posteriorly, irregularly spaced and rather weaker in later growth-stages.

HOLOTYPE AND PARATYPE. The specimen figured by Dietrich, which it has not
been possible to examine, is designated as holotype. One specimen (no. L.52113) in
the material examined is the only paratype.

LOCALITY AND HORIZON. Nitongola creek, Tendaguru, Tanganyika ; Upper
Kimmeridgian, “ Tvigonia smeet’”’ Bed. The holotype came from the same horizon
in the bed of the Maimbwi river, Tendaguru.

REMARKS. This species was considered by Dietrich to be closely comparable to
Astarte cotteausia d’Orbigny as figured by de Loriol (1875 : 100, pl. 15, fig. 42) from
the Lower Kimmeridgian of France, but it is more elongated and has a more pro-
nounced convexity of the antero-dorsal outline. According to Cottreau (1929 : 101),
d’Orbigny’s holotype of A. cotteausia is too ill-preserved to be worth figuring.
Astarte rzehaki Boehm (1883 : 558, pl. 62, fig. 33), Tithonian of Moravia, is higher at

O4 JURASSIC BIVALVIA AND GASTROPODA

its posterior extremity. Although species of Coelastarte are well known to be vari-
able, it seems desirable to regard the East African form as a separate species.

Genus PRAECONIA Stoliczka 1871
Praeconia rhomboidalis (Phillips)

1829. Isocardia rhomboidalis Phillips : 128, pl. 3, fig. 28.
1934a. Praeconia rhomboidalis (Phillips) ; Arkell : 251, pl. 33, figs. 14, 15.
1948. Pyvraeconia rhomboidalis (Phillips) ; Cox & Arkell: 28.

MATERIAL. One specimen (no. LL.35124), ex B.P. Coll.

LOCALITY AND HORIZON. Hill-top N. of Lugoba on road to Msata, Tanganyika ;
Callovian(?).

REMARKS. This specimen consists only of the posterior half of one valve, but is
an unmistakable representative of the species, the geological range of which in Europe
is from Bajocian to Oxfordian.

Genus SEEBACHIA Holub & Neumayr 1882
Seebachia janenschi Dietrich

1933. Seebachia janenschi Dietrich : 43, pl. 4, figs. 57, 63, 64; pl. 5, figs. 67, 73.

MATERIAL. Two specimens (including no. LL.35125), ex B.P. Coll.

LOCALITY AND HORIZON. Mpilepile stream, 800 yards E.N.E. of junction of main
road and Mahokondo road, Mitole, northern Mandawa area, Tanganyika ; Upper
Kimmeridgian.

REMARKS. These specimens, which are preserved in a coarse conglomerate, are
eroded, but have the unmistakable outline of B. janenschi. The larger is 52 mm.
long. The type locality of the species is Tendaguru, where it occurs in the “ Tvigonia
smeet”’ Bed.

Superfamily LUCINACEA
Family LUCINIDAE Fleming 1828
Genus LUCINA Bruguiere 1787
Lucina sp.

Pl. 15, figs. 5a, b

MATERIAL. Four internal moulds (nos. LL.35047-—50).

LOCALITY AND HORIZON. Didimtu hill, 2 miles S. of Bur Mayo, N.E. Kenya ;
Upper Lias, Toarcian, Didimtu Beds.

DeEscripTION. Of medium size (length of largest specimen c. 22 mm.), suborbi-
cular with a hexagonal tendency, length and height almost equal, umbones angular,

FROM TANGANYIKA AND KENYA 95

prosogyrous, at about anterior third of length ; inflation weak ; postero-dorsal
region compressed, limited in each valve by a strongly curved ridge running from
the umbo to the postero-ventral corner.

ReMARKS. This lucinid is not referable to any species recorded from the Upper
Lias of Europe, but the available specimens are too imperfect to serve as type
material of a new species. The species is smaller and less rectangular than Lucina
plana Zieten, in which, moreover, there is no compressed postero-dorsal area. The
presence of this area also distinguishes it from the Bajocian species L. despecta
Phillips, recorded below.

Lucina despecta Phillips
Pl. 15, fig. 9
1829. Lucina despecta Phillips : 150, pl. 9, fig. 8.

MATERIAL. Numerous specimens, all in the form of moulds, on the surface of
which traces of the original surface ornament are impressed.

LOCALITIES AND HORIZON. Kidugallo Station and 1} miles E. of Kidugallo
Station, Central Railway, Tanganyika ; Bajocian, Station Beds.

REMARKS. The specimens are slightly longer than high, with the umbo broadly
rounded, moderately prominent, and placed at about the posterior two-fifths of the
length ; the length of a typical specimen is 18:5 mm. The gently sloping postero-
dorsal outline forms a well-defined, obtuse angle with the nearly straight and verti-
cal posterior margin. The anterior margin is feebly convex and prosocline in its
general direction, joining the antero-dorsal margin in a broad curve. The surface is
ornamented with concentric ridges which are about I mm. apart on the middle of the
shell in the best-preserved specimen, with concentric threads in their intervals. Im-
pressions of anterior and posterior lateral teeth are preserved.

Lucina despecta, the holotype of which came from the Inferior Oolite of Yorkshire,
has been misinterpreted by many authors and the name has been applied to speci-
mens from later geological formations differing considerably from those from the
type-horizon. No satisfactory figure of the species, in fact, exists in the literature,
the original one of Phillips being a little foreshortened. The East African specimens
now recorded have been compared with specimens of L. despecta from Yorkshire,
and I can see no reason for separating them specifically from the English species.
Lucina paradoxa Waagen (1867 : 621, pl. 31, figs. 5a, b), from the Inferior Oolite of
Germany, seems very close to L. despecta, although a little more elongate.

Lucina cf. lirata Phillips

References to descriptions of the typical L. livata are as follows :
1829. Lucina livata Phillips : 140, pl. 6, fig. rr.
1934a. Lucina livata Phillips ; Arkell: 278, pl. 41, figs. 1-3, 7.

The form now recorded has been illustrated as follows :
1960. Lucinasp.: Joubert, pl. 9, figs. 6a, b.

96 JURASSIC BIVALVIA AND GASTROPODA

MATERIAL. One specimen (no. L.g2095).

LOCALITY AND HORIZON. Kulong, 2 miles S.W. ot Muddo Erri, N.E. Kenya ;
Callovian [?-Lower Oxfordian], Muddo Erri Limestones.

REMARKS. The fossil now recorded is an ill-preserved specimen of a well-inflated,
moderately large, suborbicular Lucina, the length and height of which were origin-
ally just over 40 mm. _ It is of much the same size and shape as typical specimens
of L. livata from the Lower Oxfordian of England, but its well-marked and fairly
evenly spaced concentric ridges are only about 0-75 mm. apart, whereas in specimens
of L. lirata from the type-locality the corresponding distance is I-I-5 mm.

Lucina cutleri sp. nov.
Ploxs, figs. 34,0

SPECIFIC NAME. After the late W. E. Cutler, the first leader of the British Museum
East Africa Expedition.

Diacnosis. Shell small (length 12 mm.), oval, only slightly longer than high,
feebly inflated. _Umbo very broadly rounded, placed at anterior two-fifths of
length, level with feebly convex postero-dorsal margin, which makes a fairly well-
defined, obtuse angle with the posterior margin. Posterior margin a little flattened,
but merging in an even curve with the strongly convex ventral margin, which is also
continuous with the anterior margin. Antero-dorsal margin straight, visible in side-
view of shell, sloping gently, and merging in a broad curve with the anterior margin.
No lunule or escutcheon. Ornament consisting of narrow concentric ridges about
one-third mm. apart in later growth-stages and separated by flat, smooth
intervals ; ridges absent from antero-dorsal region, where margin is bordered by
narrow, smooth area.

HorotyrPe. No. L.52141. The only specimen.

LocaALITy AND HoRIzON. Lilomba creek, Tendaguru, Tanganyika ; Upper
Kimmeridgian, “‘ Tvigonia smeei’’ Bed.

REMARKS. In shape this species is rather like Lucina cardinalis Contejean (1860 :
327, pl. 21, figs. 14, 15), from the Kimmeridgian of France, but it is very much
smaller. In L. tarichensis de Loriol (1895 : 33, pl. 5, figs. 5, 6), from the Oxfordian
of Switzerland, another much larger species, the antero-dorsal outline of the shell
is more excavated.

Family UNICARDIIDAE Fischer, 1887
Genus MACTROMYA Agassiz 1843
Mactromya eamesi sp. nov.

Pl. 15, figs. 8a, b, c

SPECIFIC NAME. After Dr. F. E. Eames, Chief Palaeontologist of the British
Petroleum Co., Ltd.

FROM TANGANYIKA AND KENYA 97

DiaGnosis. Small for genus (length 17 mm.), elongate-ovate, slightly inequi-
lateral, height less than two-thirds of length, beaks at anterior two-fifths of length ;
inflation moderate for genus. Umbones very broadly rounded, well incurved to
slightly prosogyrous beaks, and projecting a little above antero-dorsal outline, which
slopes gently and meets the feebly convex posterior margin in a broad curve ;
ventral margin of very feebly convexity, symmetrical ; anterior margin of feeble
convexity, not much shorter than posterior margin ; antero-dorsal outline feebly
concave, scarcely sloping. Ornament consisting of irregular concentric ribs and
rugae.

HototyrPe. No. LL.35127, ex B.P. Coll. No other material has been examined.

LOCALITY AND HORIZON. Near site of Mandawa well no. 1, Tanganyika ; Bajo-
cian(?).

REMARKS. This shell is even more elongate than Mactromya aequalis Agassiz
(1843 : 196, pl. od, figs. 5-8), a species of Bathonian-Callovian age, and is also more
strongly inflated.

Mactromya aequalis Agassiz
Pl. 15, fig. 7

1843. Mactromya aequalis Agassiz : 196, pl. od, figs. 5-8.
1912. Mactromya aequalis Agassiz ; Lissajous : 97, pl. 12, fig. 11.
19150. Arvcomya bicorvrugata Cossmann : 12, pl. 1, fig. 5 ; pl. 2, figs. 9-11 ; pl. 3, figs. 14-16.
1929. Mactromya rugosa auct. ; Weir, 34, pl. 3, figs. 16, 17 (non 18) (non Roemer).
1935a. Mactromya aequalis Agassiz ; Cox : 183, pl. 19, figs. 16, 17a, b.
1939. Mactromya aequalis Agassiz ; Stefanini: 259, pl. 27, fig. 1.
1960. Mactromya aequalis Agassiz ; Joubert, pl. 10, figs. 7a, b.
MATERIAL. Several specimens.

LOCALITIES AND HORIZONS. 33 miles W. of Melka Biini, N.E. Kenya ; Callovian,
Rukesa Shales. 14 miles W.S.W. of Rahmu, also Muddo Erri and Kulong, 2 miles
S.W. of Muddo Erri, all N.E. Kenya ; Callovian [?-Lower Oxfordian], Muddo Erri
Limestones.

REMARKS. These poorly preserved specimens are similar to those from British

Somaliland which I figured in 1935. They are characterized by the irregularity of
their concentric ridges and corrugations.

Mactromya quadrata (Roemer)
Pl. 55, figs. Lira, 6

1836. Mya vugosa Roemer : 125, pl. 9, figs. 16, 17 (non Gmelin).

1836. Mya quadrata Roemer: 126.

1840. Lutvaria concentrica Minster im Goldfuss : 258, pl. 153, figs. 5a, b.
1843. Mactromya rugosa (Roemer) ; Agassiz : 197, pl. 9c, figs. 1-23.
1872. Lucina rugosa (Roemer) ; de Loriol : 266, pl. 16, fig. 1.

1912. Mactrvomya rugosa (Roemer) ; Lissajous : 97, pl. 12, fig. 12.

MATERIAL. Four specimens.
LOCALITIES AND HORIZONS. Kailta, Golberobe hills, N.E. Kenya ; Oxfordian,

98 JURASSIC BIVALVIA AND GASTROPODA

Golberobe Beds. 17 miles S. of Rahmu, N.E. Kenya ; Upper Oxfordian, Seir
Limestones. 3 miles N.E. of Melka Dakacha, N.E. Kenya ; Upper Kimmeridgian,
Dakacha Limestones. Just W. of Mabokweni, 4 miles N.W. of Tanga, Tanganyika ;
Kimmeridgian.

REMARKS. This species, like M. aequalis, from which it scarcely differs, is
characterized by its rather elongate outline and by the irregularity of its concentric
ridges, which very commonly are undulating in places.

Family FIMBRIIDAE Nicol 1950
Genus FIMBRIA Mergele von Muhlfeld 1811

Fimbria kidugalloensis sp. nov.
Pl. 16, figs. 1a, b

Diacnosis. Shell of small-medium size (length 32 mm.), elongate, rather weakly
inflated. Umbones subangular, slightly anterior to median, protruding above
postero-dorsal outline, which is straight, sloping gently to low posterior extremity
of shell. Ventral margin of very feeble convexity ; antero-dorsal outline well
excavated ; anterior margin evenly rounded. Ornament consisting of closely and
rather unevenly spaced, thin concentric ridges, typically about 0-4 mm. apart in
later growth-stages ; many intervals between them bear one or more weak concentric
threads, together with traces of radial threads.

Horotype. No. L.54103. The only specimen.

LOCALITY AND HORIZON. I} miles E. of Kidugallo Station, Central Railway,
Tanganyika ; Bajocian, Station Beds.

REMARKS. The genus Fimbria is rare in the Bajocian. The species now described
is characterized by the fineness and close spacing of its concentric ridges. F. aspera
(Lycett) (1850 : 423, pl. 11, fig. 7), from the English Inferior Oolite, is much more
coarsely ornamented. The Kimmeridgian species F. formosa (Contejean)
(1860 : 275, pl. 13, figs. I-3) has equally fine concentric ornament but is less elongate.

Fimbria sp. “ A”’
Pl..25; fig. 6

MATERIAL. Several specimens.

LOCALITIES AND HORIZONS. Hills S. of Rahmu—Melka Murri road at localities 11
miles and 13 miles W. of Rahmu, N.E. Kenya ; Callovian, Rukesa Shales. Hills S.
of Rahmu—Melka Murri road at locality 9 miles W. of Rahmu ; also Muddo Erri,
N.E. Kenya ; Callovian {?-Lower Oxfordian], Muddo Erri Limestones.

REMARKS. Two species of Fimbria which occur in the Rukesa Shales and Muddo
Erri Limestones are represented in the material studied only by specimens which are
incomplete, much eroded, or in the form of internal moulds. The largest specimen

FROM TANGANYIKA AND KENYA 99

of the first of these species, which may be recorded as “ species A ’’, is about 60 mm.
long. The ornament consists of closely and irregularly arranged concentric ridges,
the average distance between which varies to some extent in different specimens but
is always well below 1 mm. No trace of radial ornament can be detected. This
form is less inflated than F. lajoyei (d’Archiac) (1843 : 372, pl. 27, figs. 1a—d), from
the Bathonian of north-western Europe, and differs further in the closer arrange-
ment of its concentric ridges and in the absence of radial ornament. In an English
Great Oolite specimen of F. Jajoyei figured by Morris & Lycett (1853, pl. 7, fig. 12)
the ribs are more closely spaced in later stages of growth than in early stages, but
they are further apart than in the East African specimens.

Fimbria sp. “B”
Plipx5, fies 12
1960. Corbis lajoyei d’Archiac ; Joubert, pl. 9, fig. 7a.

MATERIAL. About four specimens.

LOCALITIES AND HORIZON. Muddo Erri, and Kulong, 2 miles S.W. of Muddo Erri,
N.E. Kenya ; Callovian [?-Lower Oxfordian}], Muddo Erri Limestones.

Remarks. A second species of Fimbria found in the Muddo Erri Limestones is
the one of which a broken specimen has been figured by Joubert (1960) as Corbis
lajoyei. It has relatively distant concentric ridges with intervals in which radial
threads are well seen. This species is probably distinct from the true F. lajoyez,
but this point cannot be decided definitely owing to the poor state of preservation of
the material. Several of the Kenya specimens, like the one represented in Joubert’s
pl. 9, fig. 7b, are internal moulds and quite unidentifiable.

Fimbria quennelli sp. nov.
Pl16, fig. 7

SPECIFIC NAME. After Mr. A. M. Quennell, formerly Director of the Tanganyika
Geological Survey.

DiacGnosis. Large, with the height four-fifths of length (93 mm. in holotype),
broadly rounded anteriorly, tapering posteriorly to a low, subtruncate extremity.
Umbo moderately prominent, submedian ; postero-dorsal outline almost straight,
sloping to meet low subvertical posterior margin in a rounded-off, obtuse angle ;
antero-dorsal outline well excavated ; ventral margin asymmetrical, strongly con-
vex anteriorly, more weakly convex posteriorly. An obtuse ridge, best seen in later
stages of growth, runs from postero-ventral angle of shell towards umbo. Ornament
consisting of coarse, rounded concentric ribs separated by much narrower furrows
and crossed by weak radial riblets, best seen on anterior half of surface. Ventral
margin crenulated internally.

HOLOTYPE AND PARATYPE. Holotype, no. LL.16841 and one imperfect paratype.

100 JURASSIC BIVALVIA AND GASTROPODA

LOCALITY AND HORIZON. Usigiwa river, 6 miles W.S.W. of Kiwangwa, Bagamoyo
hinterland, Tanganyika ; Upper Oxfordian.

REMARKS. In few of the described Jurassic species of Fimbria do specimens
approach the present ones in size. De Loriol (1872 : 260 ; 1888 : 240, pl. 26, figs.
I, 2), however, has recorded some equally large specimens, from the Lower Kim-
meridgian of France and Switzerland, under the name Corbis buvigniert ; they differ
from the form now recorded in the absence both of the diagonal ridge and of radial
ornament. In Corbis jaccardi Rollier (1913 : 249, pl. 17, fig. 1), an equally large
form from the Upper Oxfordian of Switzerland, a diagonal ridge is present but the
shell is more elongate than in the African specimens, the concentric ribs are narrower,
and radial ornament is lacking. Corbis episcopalis de Loriol (1891 : 193, pl. 21,
figs. 2-4) bears radial ornament, but is much smaller than the specimens now
described and tapers less towards its posterior extremity.

Fimbria sp. “C”’
Pi, 15, fg. 10

MATERIAL. One specimen (no. LL.35126), ex B.P. Coll.

LOCALITY AND HORIZON. Lonji creek, W. of Mandawa, Tanganyika. Upper
Kimmeridgian.

REMARKS. This specimen is a broken and eroded left valve, about 53 mm. long,
with a broadly rounded umbo which is slightly posterior to median in position.
The ornament consists of broad, rounded, depressed ribs which are unequal in width
and separated by narrower intervals in which there are traces of radial threads.
The broadness of the ribs is a particularly noticeable feature. The form from the
Lower Kimmeridgian of Valfin, in the French Jura, described by de Loriol (1888 :
240, pl. 26, figs. 1, 2) as Corbis buvigmiert Deshayes, and re-named Corbis canaliculata
by Rollier (1913 : 256), is comparable in this respect, but it is a larger shell and its
ribs are not quite so broad. It is most probable that the specimen now recorded
belongs to a new species.

Genus SPHAERA J. Sowerby 1822
Sphaera subcorrugata Dietrich

1933. Corbis (Sphaera) subcorrugata Dietrich : 49, pl. 6, figs. 81, 82.

MATERIAL. Two specimens (nos. L.51169, L.51891).

LOCALITIES AND HORIZONS. N. of Kipande, near Tendaguru, Tanganyika ;
Upper Kimmeridgian, Nevinella Bed. 3 miles N.N.W. of Tapaira, near Tendaguru ;
Upper Kimmeridgian, “ Tvigonia smeet”’ Bed.

FROM TANGANYIKA AND KENYA 101

Genus SPHAERIOLA Stoliczka 1871

Sphaeriola madridi (d’Archiac)
Pl. 16, figs. 3, 4

1843. Cavdium madridi d’Archiac : 373, pl. 25, figs. 7a, b.

1867. Corbis (Sphaeva) madridi (d’Archiac) ; Laube: 38, pl. 3, fig. 4.

1921. Unicardium (Sphaeriola) madridi (d’Archiac) ; Cossmann, pl. 3, figs. 14, 15.
1948. Sphaeriola madridi (d’Archiac) ; Cox & Arkell: 35.

MATERIAL. Several specimens.

LOCALITY AND HORIZON. I mile N. of Asaharbito, N.E. Kenya ; Bathonian [? or
Callovian], Asaharbito Beds.

REMARKS. These specimens do not appear to be distinguishable from S. madridt.
The concentric corrugations which form their ornament are somewhat unequal and
irregularly distributed, much as in the specimens figured by Laube. It is probable
that the regularity of their arrangement in d’Archiac’s original figure is due to their
inaccurate representation by the artist. It has not been possible to expose the
hinge-teeth in any of the African specimens and to confirm that the dentition is that
of a Sphaeriola rather than of the externally similar genera Mactromya and Um-
cardium. A fragment of an internal mould in the material studied shows, however,
traces of crenulations of the ventral margin, such as are found in Sphaeriola and not
in the other two genera. The identification of Sphaeriola is important stratigraphi-
cally, as the known range of the genus is from Lias to Callovian and it is particularly
abundant in the Bathonian.

Superfamily CARDIACEA
Family CARDIIDAE Goldfuss 1820
Genus PROTOCARDIA Beyrich 1845

Protocardia africana sp. nov.
Pl. 16, figs. 2a, b, c

1908b. Protocardia cf. striatula Sow. ; Thevenin: 27, pl. 4, fig. 5.

Diacnosis. Of small-medium size (length of largest specimen 21 mm.), suborbi-
cular, equilateral, height slightly less than length, shell evenly and strongly inflated.
Umbones rather narrowly rounded, prominent, well incurved to the very slightly
prosogyrous beaks. Margins forming a strongly convex and uninterrupted curve ;
anterior end of shell only slightly less broad than posterior end. No diagonal ridge.
Flank unornamented except for growth-lines ; posterior area not flattened, with
about 30 granose radial riblets.

HOLOTYPE AND PARATYPES. Holotype, no. LL.35603. Several paratypes (nos.
LL.35063-72).

102 JURASSIC BIVALVIA AND GASTROPODA

LOCALITY AND HORIZON. Didimtu hill, 2 miles S. of Bur Mayo, N.E. Kenya ;
Upper Lias, Toarcian, Didimtu Beds.

REMARKS. This species resembles the European Upper Lias-Bajocian species
Protocardia subtruncata (d’Orbigny) (= Cardium truncatum Goldfuss, 1837 : 218,
pl. 143, figs. 10a—c, non Phillips) in size and in the general shape of the shell ; it
differs, however, in its slightly more prominent umbones, in the absence of a diagonal
ridge, in its more rounded posterior margin, and in the presence of granules on the
radial riblets on its posterior area. Protocardia ferruginea Rollier (= P. striatula
Benecke 1905 : 228, pl. 17, figs. 1-4, non J. de C. Sowerby), to which the Yorkshire
Dogger species erroneously attributed to P. striatula (J. de C. Sowerby) by Phillips
(1829, pl. 11, fig. 7) also probably belongs, commonly attains a considerably larger
size than that of the present East African specimens, and the riblets on its posterior
area are not so conspicuously granose.

Protocardia besairiei sp. nov.
Pl. 16, figs. 8, ga, b, 10

SPECIFIC NAME. After Monsieur H. Besairie, who collected specimens of the
species from Madagascar.

Diacnosis. Of medium size (length c. 30 mm.), ovate, strongly inequilateral,
height about two-thirds of length, beaks from anterior fifth to quarter of length;
inflation moderately strong. Umbones broadly rounded, depressed, well incurved
to the prosogyrous beaks. Postero-dorsal margin subhorizontal or gently sloping,
forming a rounded-off, obtuse angle with more or less oblique, flattened posterior
margin ; ventral margin of feeble convexity ; anterior margin strongly convex,
anterior end of shell relatively narrow for a Protocardia ; antero-dorsal outline
strongly concave. A weak diagonal ridge is present, bordering a rather flattened
posterior area. Flank ornamented with somewhat irregular and unequal, rounded
concentric ribs. Posterior area with fine radial grooves separating weak riblets.

HOLOTYPE AND PARATYPES. Holotype, no. LL.35128, ex B.P. Coll., the only
specimen from East Africa examined. Paratypes, nos. L.74972~79, from Mada-
gascar.

LOCALITIES AND HORIZON. Lihimaliao creek, at a point near Mbaru creek,
Mandawa area, Tanganyika (type-locality) ; Bajocian (?), Pindiro Shales. Mont
Bovy, Maevatanana, N.W. Madagascar ; Bajocian.

REMARKS. No closely comparable described species can be cited. Obvious
differences which distinguish it from P. beneckei Rollier (1912 : 113, 121) (= Proto-
cardia sp. ; Benecke, 1905 : 231, pl. 17, figs. 7, 8), from the Lower Bajocian of
Lorraine, are its ovate and inequilateral, rather than orbicular, outline, and its
rugose, irregularly ornamented flank.

FROM TANGANYIKA AND KENYA 103

Protocardia bipi sp. nov.
Pivr7, ties. ©) 2) 34,0

SPECIFIC NAME. After “ B.P.”’ (British Petroleum Co. Ltd.), whose geologists
collected the type material.

DiaGnosis. Of medium size (length of largest specimen c. 28 mm.), very variable
in shape and proportions, ovate to trigonally ovate, subequilateral to strongly in-
equilateral, beaks from anterior fifth of length to submedian, length exceeding height
to a variable extent, inflation moderately strong. Umbones rather narrowly
rounded, moderately prominent, well incurved to the beaks, which vary from ortho-
gyrous to strongly prosogyrous according to their position. Postero-dorsal margin
subhorizontal to gently sloping, posterior margin subvertical to strongly oblique, the
two meeting in an even curve ; ventral margin symmetrical and feebly convex to
strongly asymmetrical with posterior flattening ; anterior margin flat to feebly con-
vex, its inclination variable. A distinct diagonal ridge, well marked in earlier
growth-stages, delimits the slightly flattened posterior area. Flank unornamented
except for growth-rugae. Posterior area with fine radial grooves.

HOLOTYPE AND PARATYPES. Holotype, no. LL.35129 ; several paratypes, in-
cluding nos. LL.35130-31 ; all ex B.P. Coll.

LOCALITY AND HORIZON. Lihimaliao creek, at a point near Mbaru creek, Man-
dawa area, Tanganyika ; Bajocian (?), Pindiro Shales.

REMARKS. This species is highly variable. The more elongate specimens show
some approach in shape to P. besairiei, described above, but their beaks are not
prosogyrous, the umbonal ridge does not persist to the postero-ventral angle of the
shell, and the flank is more delicately ornamented.

Protocardia consobrina (Terquem & Jourdy)
Pl, 16, fig.5

1869. Cardium consobrinum Terquem & Jourdy : 102, pl. 11, figs. 1-3.

MATERIAL. Two specimens (nos. LL.35132-33), ex B.P. Coll.

LOCALITY AND HORIZON. Changogo—Magindu track 4 miles from Changogo town,
Tanganyika ; Callovian.

REMARKS. In these specimens, the larger of which is 27 mm. long, the shell is
suborbicular and strongly and evenly inflated, with no diagonal ridge present at any
stage of growth. The umbo is submedian and moderately prominent. The flank is
smooth, while the posterior area bears shallow radial grooves, about 12 of which are
distinguishable on the better preserved specimen, separating flattened radial riblets.

I cannot distinguish between the African specimens and P. consobrina, as described
and figured by its authors from the Bathonian of France. A French Callovian spe-
cies, P. boone: Cossmann (1924 : 47, pl. 6, figs. 57, 58), is very similar in size and
shape, but has finer and more numerous radial riblets on its posterior area. P.

104 JURASSIC BIVALVIA AND GASTROPODA

consobrina has been recorded from Madagascar by Douvillé and others, while Dacqué
(1910 : 30) has recorded a “‘ Cardium sp.’’, said to resemble this species, from Callo-
vian beds at Km.127 along the railway from Dar-es-Salaam to Morogoro.

Protocardia rahmuensis sp. nov.
Pl. 17, figs. 4a, b

DiaGnosis. Of medium size (length of holotype c. 20 mm.), suborbicular, length
and height almost equal, rather strongly inflated. Umbo prominent, median, with
strongly convex outline. Antero-dorsal outline well excavated, anterior and vent-
ral margins forming an even curve of strong convexity ; posterior margin slightly
less convex than anterior one and forming a rather ill-defined, obtuse angle with
ventral margin ; level of postero-dorsal margin slightly higher than that of antero-
dorsal margin. Posterior area separated from flank by obtuse ridge and bearing
nearly 20 radial riblets. Traces of fine concentric ridges preserved on flank of shell.

Hototyre. No. L.g2257, an internal mould. One or two further specimens are
ill-preserved and should scarcely rank as paratypes.

LOCALITIES AND HORIZON. River section W. of Rahmu—E] Wak road, 54 miles
S.W. of Rahmu (type-locality) ; Uacha, 6 miles S. of Rahmu, S.E. Kenya : both
Oxfordian, Rahmu Shales.

REMARKS. The most closely comparable European Oxfordian species is Proto-
cardia intexta (Minster), illustrated in a number of standard monographs by figures
many of which have been subsequently re-named. InP. voemeri Rollier (for Cardiwm
intextum Roemer (1839, pl. 19, fig. 3 ; also de Loriol 1897, pl. 12, fig. 10)) the antero-
dorsal and postero-dorsal outlines of the shell are less strongly excavated. Pvoto-
cardia valbertensis de Loriol (1901 : 61, pl. 4, figs. 12-14), which Roeder (1882 : 89,
pl. 3, figs. 4a-c) had figured as P. intexta, closely resembles the African species in
outline and ornament, but is much smaller. A poorly preserved Protocardia of
about the same size which occurs commonly in the Golberobe Beds (Oxfordian) has
a less prominent umbo and appears to belong to a different species.

Protocardia schencki Miller
Pl. 17, figs. 5a, b

1900. Pyrotocardia schencki Miller : 544, pl. 19, figs. 12, 13.
1914b. Protocardia schencki Miller ; Hennig: 170.
1933. Pyvotocardia schenchi Miiller ; Dietrich : 52.

MATERIAL. Numerous specimens.

LOCALITIES AND HORIZONS. Scarp and stream bed at Kindope, N.N.W. of
Tendaguru, Tanganyika ; Upper Kimmeridgian, Nerinella Bed. Tingutitinguti
creek, Nitongola creek, and Kindope river, all near Tendaguru, Tanganyika ; Upper
Kimmeridgian, ‘“‘ Tvigonia smeei’’ Bed. Kinjele, 5 miles W. of Mtapaia, N. of
Tendaguru, Tanganyika ; Upper Kimmeridgian, Indogrammatodon Bed.

FROM TANGANYIKA AND KENYA 105

REMARKS. This is a small, orbicular, equilateral Protocardia, most specimens of
which are evenly inflated, although a few have an obscure diagonal angulation. The
largest specimens are about 15 mm. long. In one specimen which retains some of its
original shell it can be seen that there are 15 or more riblets on the posterior area and
that in earlier stages of growth these form a delicate reticulate pattern with closely
arranged growth-threads.

Protocardia suprajurensis (Contejean)
Pl. 17; fige6

1860. Cardium suprajurense Contejean : 276, pl. 14, figs. 11, 12.

1875. Cardium suprajurense Contejean ; de Loriol : 61, pl. 13, fig. 43.
1878. Cardium suprajurense Contejean ; Struckmann : 94, pl. 4, figs. 5, 6.
1905. Protocardia suprajurensis (Contejean) ; Schmidt : 173.

MATERIAL. One specimen (no. LL.35134), ex B.P. Coll.

LOCALITY AND HORIZON. N. of Matapwa, Pindiro area, Tanganyika ; Upper
Kimmeridgian.

REMARKS. The specimen consists of one valve of a subequilateral, moderately
and evenly inflated representative of the Cardiidae, the height of which (c. 29 mm.)
is approximately equal to the length. It is devoid of ornament except in later stages
of growth, in which there are low, round-topped concentric ribs slightly more than 1
mm. wide, separated by narrow intervals. No trace of radial ribbing can be seen on
the posterior part of the surface, which, however, is rather obscured by matrix.

This specimen seems to belong to Protocardia suprajurensis, a Kimmeridgian form
originally described from the French Jura, where specimens attain about the same
size. The affinities of the species have been disputed, Brauns having considered it
to belong to Amisocardia. De Loriol and Struckmann, however, have expressed the
opinion that it is a true cardiid, and it seems to be related to a group of species found
in the Lower Cretaceous and similarly ornamented with concentric ribs. This group
includes Cardium rothpletzi Dietrich, from the Neocomian of Tendaguru and C.
sphaeroideum Forbes, from the Aptian of England, both of which attain a consider-
ably larger size. Dietrich referred C. rothpletzi to his subgenus Tendagurium, but
it does not appear to be closely related to the type-species of that taxon, and it is
here included in Protocardia, sensu lato.

Subgenus TENDAGURIUM Dietrich 1933

Protocardia (Tendagurium) bannesiana (Contejean)

1860. Cardium bannesianum (ex Thurmann, MS.), Contejean : 276, pl. 15, figs. 1-5.
1862. Cardium banneianum Thurmann ; Thurmann & Etallon : 181, pl. 22, figs. ra, b.
1872. Cardium banneianum Thurmann ; de Loriol : 249, pl. 15, figs. 1, 2.

1897. Cardium banneianum Thurmann ; Futterer : 600.

1912. Nemocardium banneianum Thurmann ; Lissajous: 91, pl. 11, fig. ro.

1930. Cardium banneanum Etallon ; Basse : 140, pl. 5, fig. 8.

1960. Cardium (Protocardia?) bannesium Contejean ; Joubert, pl. ro, fig. 6b.

106 JURASSIC BIVALVIA AND GASTROPODA

MATERIAL. One specimen (no. L.g2194).

LOCALITY AND HORIZON. Hereri river crossing, 3 miles S. of Melka Kunha, N.E.
Kenya ; Kimmeridgian, Hereri Shales.

Remarks. Dietrich founded the subgenus Tendagurium for equilateral Mesozoic
Cardiidae lacking radial ornament. The question whether the type-species, Cardium
propebanneianum, is specifically distinct from C. bannestanum is discussed below.
There is no doubt that the two forms are closely related. In Europe this species
appears to be confined to the Kimmeridgian.

Protocardia (Tendagurium) propebanneiana (Dietrich)
Pl. 16, fig: 6

1933. Cardium (Tendagurium) propebanneianum Dietrich : 50, pl. 6, figs. 92, 93.

MATERIAL. About Io specimens.

LOCALITY AND HORIZON. Tingutitinguti creek, Tendaguru, Tanganyika ; Upper
Kimmeridgian, “‘ Tvigonia smeei’’ Bed.

REMARKS. Dietrich, when describing this species, discussed its possible identity
with Cardium bannesianum Contejean, and concluded that it differs in its better
developed posterior ridge and its less strongly convex pallial margin. These differ-
ences, however, are not strongly marked. Dietrich mentions a specimen of C. pro-
pebanneianum 80 mm. long, and the length of the largest of the specimens now
recorded is 70 mm. These measurements are not greatly in excess of the maximum
length of 65 mm. given by de Loriol for C. bannesianum. Dietrich mentions and
illustrates a distinct pallial sinus in C. propebanneianum, whereas there is no sinus in
C. bannesianum, but his figure has evidently been retouched to make the sinus
obvious. Some of the specimens now recorded are internal moulds, but the pallial
line is not clearly seen in any of them. The posterior adductor scar has, however, a
well-marked anterior angle, and if this marks the point where the pallial line met the
scar it is possible that a sinus may have been present and that the specific separation
from C. bannesianum is justified.

Superfamily ISOCARDIACEA [GLOSSACEA|
Family CERATOMYOPSIDAE Cox 1964
Genus CERATOMYOPSIS Cossmann 1915

Ceratomyopsis basochiana (Defrance)
P75 Mest oOay.0

1822. Isocardia basochiana Defrance : 18.

1822b. Isocarvdia basochiana Defrance ; J. Sowerby, Part 7, “‘ Isocardia”’’ pl., fig. 4.
1850a. Ceromya sarthacensis d’Orbigny : 336.

1900. IJsocardia striata d’Orbigny ; Miiller : 534, pl. 18, figs. 1a, b (non d’Orbigny).

FROM TANGANYIKA AND KENYA 107

1903. Isocardia basochiana Detrance ; Bigot & Matte : 167.

1910. Cevomya concentrica (Sow.) ; Dacqué: 33, pl. 5, fig. 5 (nom Sowerby sp.).
1913. Ceromyopsis kiliani Rollier : 268, pl. 15, fig. 9.

1915). Cevatonvyopsis dassei Cossmann : 7, pl. 2, figs. 1-3.

1924. Isocardia substriata Hennig : 67 (partim).

1925. Ceromya sarthacensis d’Orbigny ; Cottreau : 9, pl. 37, figs. 7, 8.

1937b. Ceromyopsis substriata (Hennig) ; Cox : 202, pl. 16, fig. 4.

1960. Cevomyopsis kiliani Rollier ; Joubert, pl. 11, figs. 2a, b.

MATERIAL. Three specimens.

LOCALITIES AND HORIZONS. 2 miles E. of Magindu Station, Central Railway,
Tanganyika ; Callovian. Hills S. of Rahmu—Melka Murri road, 13 miles W. of
Rahmu, N.E. Kenya ; Callovian, Rukesa Shales. Kulong, 2 miles S.W. of Muddo
Erri, N.E. Kenya ; Callovian [?-Lower Oxfordian], Muddo Erri Limestones.

REMARKS. Defrance’s description and Sowerby’s figure of this species have been
overlooked by most authors. Bigot & Matte have recorded that Defrance’s holo-
type was from the Callovian and there seems no doubt that the species is identical
with the later described sarthacensis d’Orbigny, kiliami Rollier and dassei Cossmann,
all from the Callovian of France. The specimen from the Callovian of Tanganyika
figured by Miiller as Jsocardia striata and included by Hennig in his Jsocardia sub-
striata is characterized by its strongly coiled umbo, the tip of which is pointed up-
wards so as to form the summit of the shell. The specimen from Tanganyika now
recorded (the one figured by me previously under Hennig’s name substriata) closely
resembles it in this respect. These shells are now considered to fall within the range
of variation of C. basochiana.

Ceratomyopsis striata (d’Orbigny)
PlL17, fig. 9

1822. Jsocardia striata d’Orbigny : 104, pl. 2, figs. 7-9.

1875. JIsocardia striata d’Orbigny ; de Loriol : 56, pl. 13, figs. 35, 36.
1897. Isocardia striata d’Orbigny ; Futterer : 602, pl. 21, figs. 3, 3a.
1929. Ceromyopsis striata d’Orbigny, Futterer ; Weir : 32, pl. 3, fig. 8.
19354. Ceromyopsis striata (d’Orbigny) ; Cox: 188, pl. 19, fig. Io.
1960. Cevomvopsis striata (d’Orbigny) ; Joubert, pl. 11, figs. 3a, b.

MATERIAL. One specimen (no. L.g21g1).

LOCALITY AND HORIZON. Hereri river crossing, 3 miles S. of Melka Kunha, N.E.
Kenya ; Kimmeridgian, Hereri Shales.

REMARKS. It is not certain that this species differs morphologically from C.
basochiana (Defrance), described in the same year, although it has been customary
to draw a specific distinction between specimens from their respective horizons,
Kimmeridgian and Callovian. The variability of C. striata is illustrated by the
figures published by de Loriol (1875).

108 JURASSIC BIVALVIA AND GASTROPODA
Superfamily ARCTICACEA
Family ARCTICIDAE Newton 1891
Genus PRONOELLA Fischer 1887

Pronoella pindiroensis sp. nov.
Pl§.x7 fies: 12, 13, 144,10) 15310; 174,70

Diacnosis. Of medium size (length of largest specimen 33 mm.), elongate-cunei-
form, strongly inequilateral, height from one-half to two-thirds of length, beaks
between anterior quarter and fifth of length ; some but not all specimens posteriorly
rostrate, some strongly inflated, others only moderately so even when apparently
uncrushed. Umbo not prominent, broadly rounded to obtusely angular, slightly
incurved to prosogyrous beak. Postero-dorsal outline parasigmoidal to feebly and
evenly convex and ventral margin posteriorly sinuate or feebly and evenly convex
according to presence or absence of posterior rostrum ; posterior margin low, almost
straight, oblique ; antero-dorsal outline slightly concave ; anterior margin broadly
convex. Lunule moderately broad and deep, not distinctly bordered ; bordering
ridges of escutcheon absent or ill-defined. An obtuse angulation, straight or para-
sigmoidal according to presence or absence of posterior rostrum, and scarcely defined
in some specimens, runs from beak to postero-ventral corner. Surface ornamented
with irregular concentric threads or rugae which are present on all the anterior part
but tend to disappear on the posterior part of the flank, and are absent from the
posterior area.

HOLOTYPE AND PARATYPES. Holotype, no. LL.35135. There are numerous
paratypes including nos. LL.35136—40, but many are crushed. All ex B.P. Coll.

LOCALITIES AND HORIZON. Near site of Mandawa well no. 1, Tanganyika (type-
locality) ; Lihimaliao creek, at a point near Mbaru creek, Mandawa area, Tangan-
yika ; Bajocian (?), Pindiro Shales.

DeEscripTIon. The description given in the diagnosis may be supplemented by
an account of the dentition, which is that of a typical Pronoella. Right valve with
an elongate posterior cardinal (3b), obscurely bifid and almost parallel with postero-
dorsal margin ; a triangular median cardinal (1) with its broad apex well separated
from the beak and tapering anteriorly to be continued by a thin anterior lateral
(Ai) ; a very thin, elongate anterior cardinal (3a) passing into an equally thin lateral
(Ai), the two separated by a very narrow recess from the adjacent margin ; and
an elongate posterior lateral (Pi), separated by a recess from the margin : left valve
with three cardinal teeth of which the posterior (40) is thin and elongate, lying along
the lower margin of the ligamental nymph, the median (20) is stout, bifid, and in-
clined backward from the beak, and the anterior (2a) is moderately stout and elon-
gate and lies close to the antero-dorsal margin.

REMARKS. At first sight the specimens included in this species appear to belong
to at least two different species, but there appears to be complete intergradation
between specimens with a well-developed posterior rostrum and those with no ros-

FROM TANGANYIKA AND KENYA 109

trum. The rostrate specimens closely resemble the Hettangian species Cypricardia
triangularis Terquem (1855 : 304, pl. 20, figs. 14, 14a), which may be a Prenoella.
Except for the small size the present species also much resembles Pronoella elongata
Cox, from the Aalenian of England, type species of the subgenus Gythemon Casey, but
its dentition resembles that of Pronoella s.str. (Casey 1952 : 145, text-fig. 34) rather
than that of Gythemon (Casey : 151, text-fig. 47) in the relative strengths of the
various hinge-teeth and in the anteriorly pointing direction of the tooth (1).

Pronoella putealis sp. nov.
Plt 17/ figs? 10, rr

Diacnosis. Of small-medium size (length of holotype 21 mm.), cuneiform,
moderately inequilateral, height two-thirds of length, beaks at anterior three-
sevenths of length ; inflation apparently only moderate (the specimens have, how-
ever, suffered compression). Umbo obtusely angular, moderately prominent,
slightly incurved to prosogyrous beak. Antero-dorsal and postero-dorsal outlines
concave, the latter forming an obtuse angle with the low, subvertical posterior mar-
gin ; ventral margin of feeble to moderate convexity ; anterior margin broadly
convex. No bordered lunule or escutcheon ; a thin, raised keel runs from the beak
to the postero-ventral corner. Surface ornamented with fine, regular concentric
threads, which are absent from the area dorsal to the keel. Hinge-teeth (seen only
in fragments from well washings) as in typical Pronoella, but median cardinals (1)
and (2a) stouter in than P. pindiroensis.

HOLOTYPE AND PARATYPES. Holotype, no. LL.35141 ; two paratypes, including
no. LL.35142. There are also several fragments from well sample washings. All
ex B.P. Coll.

LOCALITIES AND HORIZON. Lihimaliao creek, at a point near Mbaru creek,
Mandawa area, Tanganyika (type-locality) ; Mandawa well no. 6, Tanganyika (depths
46-64 feet) : Bajocian (?), Pindiro Shales.

REMARKS. This species is smaller than P. pindiroensts and is also readily distin-
guishable by its fine, regular concentric ornament.

Pronoella kidugalloensis sp. nov.
Pl. 18, figs. 1a, b

Diacnosis. Of medium size (length 24-5 mm.), cuneiform, strongly inequilateral,
height about three-quarters of length, beaks at anterior sixth of length, inflation
moderately strong. Umbo broadly rounded, slightly incurved to the prosogyrous
beak, its outline continuous posteriorly with the feebly convex, rather steeply
sloping postero-dorsal outline of shell. Posterior margin low, subvertical ; ventral
margin with very shallow sinus posterior to middle of its length, and merging anterior-
ly in a broad curve with the feebly convex, prosocline anterior margin ; antero-
dorsal outline a little excavated. Lunule broad and deep ; escutcheon broad but

110 JURASSIC BIVALVIA AND GASTROPODA

shallow, its bordering ridges rather obscure ; diagonal ridge distinct near umbo but
dying out before reaching postero-ventral corner of shell. Ornament consisting of
narrow and rather irregularly spaced concentric folds (obliterated by erosion on
part of surface of holotype). Internal characters unknown.

HoLotypPE. No. LL.35143, ex B.P. Coll. There is also a fragment of a second
specimen.

LOCALITY AND HORIZON. 14 miles N.N.W. of Kidugallo, Central Railway,
Tanganyika ; Bajocian.

REMARKS. This species is referred to Pronoella on account of its general resemb-
lance to P. pindiroensis sp. nov., from which it differs in its less elongate but more
strongly inequilateral form, its broader lunule, and its more strongly ribbed surface.

Genus ANISOCARDIA Munier-Chalmas 1863

Anisocardia arkelli sp. nov.
Pl. 18, figs. 5a, b

SPECIFIC NAME. After the late Dr. W. J. Arkell.

DiaGnosis. Of medium size (length of largest specimen 17:5 mm.), subtrigonal,
inequilateral, length well exceeding height, beaks at about anterior third of length ;
inflation strong. Umbo prominent, narrowly rounded, well incurved, with beak
strongly prosogyrous. Postero-dorsal outline feebly convex, steeply sloping ;
posterior margin low, sharply convex ; ventral margin of moderate and even con-
vexity ; anterior margin narrowly rounded, with anterior extremity low, at about
one-quarter of shell height ; antero-dorsal outline strongly concave. No distinct
posterior umbonal ridge present.

HOLOTYPE AND PARATYPES. Holotype, no. LL.35051. Four paratypes, nos. LL.
35052-55:

LOCALITY AND HORIZON. Didimtu hill, 2 miles S. of Bur Mayo, N.E. Kenya ;
Upper Lias, Toarcian, Didimtu Beds.

REMARKS. This species bears some resemblance to A. gibbosa (Minster) (Cox,
1947 : 161, text-figs. 29a, b), from the European Bajocian, but is smaller and less
gibbose.

Anisocardia didimtuensis sp. nov.
Pl. 18, fig. 4

Dr1aGcnosis. Of medium size (length of holotype 20-8 mm.), subtrigonal, inequi-
lateral, length well exceeding height, beaks at about anterior third of length ; in-
flation strong ; umbo prominent, narrowly rounded, very strongly incurved, with
beak strongly prosogyrous. Postero-dorsal outline strongly convex near umbo,
slightly concave more posteriorly, steeply sloping, forming an obtuse angle with short,

FROM TANGANYIKA AND KENYA 11

subvertical posterior margin ; ventral margin of even and very feeble convexity ;
anterior margin abruptly rounded, anterior extremity low, at about one-fifth of shell
height. No well-defined posterior umbonal ridge present.

HotrotyrPe. No. L.35056. The only specimen.

LOCALITY AND HORIZON. Didimtu hill, 2 miles S. of Bur Mayo, N.E. Kenya ;
Upper Lias, Toarcian, Didimtu Beds.

REMARKS. This species appears to be distinct from A. arkelli, with which it
occurs associated. The umbo is more elevated than in that species, the beak
considerably more incurved and strongly prosogyrous, and the antero-dorsal outline
more excavated. The slight concavity of the postero-dorsal outline, moreover, is
not seen in A. arkelli.

A specimen from the Upper Lias of Madagascar figured by Thevenin (1908) : 29,
text-fig. 24) as Gresslya cf. pinguis Agassiz is not a Gresslya, but an Antsocardia which
differs from the species now described in its rather higher anterior extremity and its
less strongly prosogyrous beak. Awmisocardia fullonica Cox (1947 : 164, text-figs.
34a, b ; pl. 9, fig. 73), from the Lower Bathonian (Fuller’s Earth Rock) of southern
England, closely resembles the form now described but is more tumid and has a less
evenly convex ventral margin.

Anisocardia ayersi sp. nov.
Pl. 18, figs. 6a, b

SPECIFIC NAME. After Mr. F. M. Ayers, of the Kenya Geological Survey, who
first discovered the beds at Didimtu.

DiaGnosis. Of medium size (length of holotype 20-5 mm.), subovate, length
slightly exceeding height, beaks at about anterior quarter of length, inflation moder-
ate. Umbo not prominent, narrowly rounded in outline, moderately incurved and
prosogyrous. Postero-dorsal outline feebly convex, sloping gently, and forming an
obtuse angle with the straight, slightly oblique posterior margin ; ventral margin of
moderate and even convexity ; antero-dorsal outline slightly concave ; anterior

margin broadly rounded, anterior extremity at about one-third of shell height. No
distinct posterior umbonal ridge present.

HototyPe. No. LL.35057. The only specimen.

LOCALITY AND HORIZON. Didimtu hill, 2 miles S. of Bur Mayo, N.E. Kenya ;
Upper Lias, Toarcian, Didimtu Beds.

REMARKS. This species bears some resemblance to A. stamfordensis Cox (1947 :
160, text-figs. 24a, b ; pl. 9, fig. 72), Bajocian of England, but its umbo is less promin-
ent, it lacks a posterior umbonal ridge, and its ventral margin is not flattened poste-
riorly, as in that species.

sais JURASSIC BIVALVIA AND GASTROPODA

Anisocardia minima (J. Sowerby)
Pl. 18, fig. 8

1821a. Isocavdia minima J. Sowerby : 171, pl. 295, fig. 1.
1934a. Anisocardia minima (J. Sowerby) ; Arkell : 275, pl. 36, figs. 8-11.
1947. Anisocardia minima (J. Sowerby) ; Cox: 170, text-figs. 43a, b.

MATERIAL. One specimen (no. L.g2120).

LOCALITY AND HORIZON. Hills S. of Rahmu—Melka Murri road, 13 miles W. of
Rahmu, N.E. Kenya ; Callovian, Rukesa Shales.

REMARKS. This specimen, about 21 mm. long, is not distinguishable from English
specimens of this well-known species, discussed in my 1947 paper. The range of the
species in Europe is from Upper Bajocian to Callovian or possibly Oxfordian.

Anisocardia kinjeleena sp. nov.
Pl. 18, fies 3

DiaGnosts. Shell of medium size for the genus (length of holotype 17-5 mm.),
subquadrate, with height little less than length ; inflation rather feeble. Umbo
projecting slightly above postero-dorsal outline, and well incurved to strongly pro-
sogyrous beak, which lies at about anterior quarter of length of shell. Posterior
margin straight, forming a rounded-off angle which is only slightly greater than a
right angle with straight postero-dorsal outline and a slightly less well-defined angle
with moderately and symmetrically convex ventral margin. Anterior end of shell
rather low, with strongly convex margin ; antero-dorsal outline well excavated.
Diagonal ridge sharp, presenting an upward-facing convexity along its entire length,
and delimiting a strongly concave postero-dorsal area.

HOLOTYPE AND PARATYPES. Holotype, no. L.51938. Three paratypes.

LOCALITIES AND HORIZONS. Kinjele, 5 miles W. of Mtapaia, N. of Tendaguru,
Tanganyika (type-locality) ; Upper Kimmeridgian, Indogrammatodon Bed. Kin-
dope valley, N.N.W. of Tendaguru ; Upper Kimmeridgian, Nerinella Bed.

REMARKS. This species is referred to Anisocardia rather than to Opis as the
specimens have no trace of concentric ornament, which is usually visible even on
internal moulds of the latter genus. Its subquadrate form and high postero-dorsal
angle serve to distinguish it from any species of Anisocardia described previously.

Genus EOTRAPEZIUM Douvillé 1913

Eotrapezium ? africanum sp. nov.
Pl. 18, figs. 7a, b

Dracnosis. Of medium size (length of holotype 32:3 mm.), subrectangular,
elongate, inequilateral, beaks at anterior quarter of length, inflation moderate.
Umbonal outline obtuse, umbones slightly incurved ; postero-dorsal margin almost

FROM TANGANYIKA AND KENYA 113

straight, subhorizontal, forming an obtuse angle with the straight, slightly oblique
posterior margin ; ventral margin almost straight ; antero-dorsal outline strongly
concave ; anterior margin strongly convex. An obtusely rounded ridge, curved
with an upward-facing convexity, runs from the umbo to the postero-ventral corner
in each valve. Pallial line entire.

Horotyrr. No. LL.35058. There are also two very imperfect specimens.

LOCALITY AND HORIZON. Didimtu hill, 2 miles S. of Bur Mayo, N.E. Kenya ;
Upper Lias, Toarcian, Didimtu Beds.

REMARKS. The specimens are internal moulds and details of their hinge-structure
cannot be ascertained. The species is referred, with a query, to Eotrapeziwm because
its subrectangular outline resembles that of some specimens of the Lower Liassic
type species, Mesodesma germari Dunker, such as those from Portugal figured by
Boehm (1901, pl. 10, figs. 6, 7). Alternatively, it could conceivably belong to the
Astartidae, but its strongly excavated antero-dorsal outline and greater inflation
distinguish it from known species of the astartid subgenus Leckhamptonia, in which
the rectangular outline of the shell is somewhat similar. No closely comparable
species has been described previously from the Upper Lias.

Eotrapezium ? thompsoni sp. nov.
Pl. 18, figs. 2a, b

SPECIFIC NAME. After Mr. A. O. Thompson, of the Kenya Geological Survey,
collector of the type material.

DiacGnosis. Of small-medium size (length 17 mm.), trapeziform, inequilateral,
length not greatly exceeding height, beaks at anterior quarter of length ; inflation
rather weak (but holotype somewhat crushed). _ Umbonal outline obtuse, umbones
scarcely incurved ; postero-dorsal outline feebly convex, subhorizontal, forming an
obtuse angle with the straight, slightly oblique posterior margin ; ventral margin of
feeble convexity, diverging slightly from postero-dorsal outline in a posterior direc-
tion ; antero-dorsal outline moderately concave ; anterior margin strongly convex.
An obtusely rounded ridge, curved with an upward facing convexity, runs from the
umbo to the postero-ventral corner. Surface ornamented with concentric threads.

HoLotyre. No. LL.35061. There is also one very imperfect specimen.

LOCALITY AND HORIZON. Didimtu hill, 2 miles S. of Bur Mayo, N.E. Kenya.
Upper Lias, Toarcian, Didimtu Beds.

REMARKS. This species bears a general resemblance to Eotrapezium? africanum,
described above, but differs in its much shorter form.

Eotrapezium ? kenti sp. nov.
Pl. 18, figs. ga, b, 10a, b

SPECIFIC NAME. After Dr. P. E. Kent, of the British Petroleum Company, Ltd.
Dracnosis. Shell of medium size (length of holotype c. 27 mm.), ovate-cuneiform,

114 JURASSIC BIVALVIA AND GASTROPODA

height about four-fifths of length, inflation moderate. Umbo broadly rounded,
incurved to the moderately prosogyrous beak, which is situated at the anterior
quarter of the length of the shell ; outline of umbo continuous with the evenly
convex postero-dorsal outline, which slopes at a fairly steep angle to the low, abruptly
rounded posterior extremity. Ventral margin feebly convex, continuous with
strongly and evenly convex anterior margin ; antero-dorsal outline well excavated.
Lunule shallow, not bordered ; escutcheon ridge as well as ridge running diagonally
from umbo to postero-ventral corner weakly defined. Surface ornamented in
later growth-stages with narrow, irregular concentric undulations.

Hinge-teeth of right valve consisting of elongated outer posterior cardinal (4b)
adjacent to nymph, a strong, well elongated inner posterior cardinal (2 of Douvillé,
2b, of Casey) sloping back from the beak, an equally strong and similarly well elon-
gated anterior cardinal (2b, of Casey) diverging at obtuse angle from inner posterior
cardinal, and an anterior lateral Ail, which is separated from the anterior cardinal
by a distinct constriction.

HOLOTYPE AND PARATYPES. Holotype, no. LL.35144 ; two paratypes, including
no. LL.35145 ; all ex B.P. Coll.

LOCALITY AND HORIZON. Magole, 5 miles N.W. of Kidugallo, Tanganyika ; Bajo-
cian.

RemMARKS. As the dentition of the right valve is unknown it is not possible to
assign this species to any genus with complete confidence. The hinge of the left
valve agrees with that of the type-species of Eotrapezium, Mesodesma german Dun-
ker, from the Lower Lias, as figured by Boehm (1901 : 238, fig. 19) and by Douvillé
(1913 : 455, fig. 38), in the elongation and broad divergence of the two inner cardinal
teeth, but the anterior of these passes without any interruption into the anterior
lateral in E. germari and in two other species of Eotrapezium figured by Douvillé
(1913, figs. 40, 42), whereas it is separated from it by a distinct constriction in the
species now described. The dentition of the left valve of this species also bears some
resemblance to that of Anisocardia (Antiquicyprina) loweana (Morris & Lycett),
from the English Bathonian, as figured by Casey (1952 : 151, fig. 49), but the two
inner cardinal teeth are much more elongated than in the species in question.

Family NEOMIODONTIDAE Casey 1955
Genus EOMIODON Cox 1935

Eomiodon baroni (Newton)
Pl) 18, fe. IE
1889. Astarte? bavoni Newton : 336, pl. 14, figs. 9-11.
1936. Astarte baron Newton ; Besairie: 121, pl. 7, figs. 1, 2.
MATERIAL. Several specimens.
LOCALITIES AND HORIZONS. Quarries N.N.E. of Ngerengere, Central Railway,
Tanganyika ; Bajocian (?). 6 miles N.W. of Kidugallo, Tanganyika ; Bajocian
(B;P: Coll.)

FROM TANGANYIKA AND KENYA 115

REMARKS. Newton’s holotype of Astarte? baron, from Madagascar, is so ill-
preserved that when describing the specimens from India (Cox 19350 : 7, pl. I, figs.
17-19) upon which I founded the genus and species Eomiodon indicus I did not
recognize their generic affinity with it. Examination of further material from
Madagascar has left me with no doubt on this point. The two forms are similar in
size and outline, but E. indicus is much more strongly inflated than any specimens of
the Madagascan species which I have examined, and it is doubtful if they should be
placed in synonymy.

Of the specimens now recorded fom Tanganyika, those from Ngerengere are quite
typical. Those from the locality near Kidugallo, only two in number, are relatively
small, the larger being only 19 mm. long, and the relatively wide-spaced concentric
ridges of the earlier growth-stages are replaced by closely spaced ridges at a shorter
distance from the umbo than in typical specimens. They could possibly belong to a
distinct species or subspecies, but there is insufficient material for a decision to be
reached on this point.

Eomiodon tanganyicensis sp. nov.
Pl. x8, figs. 124, 6, 13

DiaGnosis. Of medium size (length of holotype c. 27 mm.), cuneiform, moderately
inflated. Umbones anteriorly placed but not quite terminal, well incurved to the
strongly prosogyrous beaks. Postero-dorsal outline strongly convex anteriorly, less
convex posteriorly, sloping to the low, subangular posterior extremity of the shell.
Ventral margin strongly convex, merging anteriorly with the convex anterior mar-
gin ; antero-dorsal outline slightly concave. Escutcheon not distinctly bordered
by aridge. Surface of shell without marked concentric ornament.

Cardinal teeth consisting, in left valve, of stoutly triangular, anteriorly directed
anterior tooth (2b) very close to antero-dorsal margin, and of a quite strong, elongate
posterior tooth (4b) widely divergent from 2) ; in right valve, of stout, triangular,
mesially placed tooth (3b) and narrow, weak anterior tooth (3a). Right valve with
strong, lamelliform posterior lateral tooth (Pi) and a weaker, lamelliform anterior
lateral (Ai), each separated from shell margin by a recess for the reception of a lateral
tooth formed by a projection from the corresponding part of margin of left valve.

HOLOTYPE AND PARATYPES. Holotype, no. LL.7215. About 20 paratypes.

LOCALITY AND HORIZON. Quarries N.N.E. of Ngerengere, Central Railway, Tanga-
nyika ; Bajocian (?).

REMARKS. The specimens are encrusted with fine sandy material, but their lack
of concentric ornament appears to be an original feature and to distinguish them
from E. baron. The lack of an angular ridge bordering an escutcheon is another
point of difference. They are less gibbose than EF. baroni, but it is not possible to
say if this difference is entirely due to the compression which most of them have
undergone. Their dentition is that of a typical Eomiodon.

116 JURASSIC BIVALVIA AND GASTROPODA

Eomiodon dinosaurianum sp. nov.
Pl. 18, figs. 15a, b, 16a, b

1933. Cyrenasp.; Dietrich: 46, pl. 8, fig. 125; ? pl. 11, fig. 147.

DiAGNosis. Shell small (usual length c. 12 mm.), trigonally ovate, variable in
proportions but always longer than high, subequilateral to moderately inequilateral,
with beaks lying between a position slightly posterior to median and the anterior
quarter of the length ; inflation moderate (most specimens, however, are crushed).
Umbo broadly rounded, slightly incurved to the moderately prosogyrous beak, its
outline continuous with straight postero-dorsal outline of shell ; postero-dorsal
outline sloping at a moderately steep angle to meet the usually short, straight
posterior margin in an obtuse angle ; ventral margin convex to a variable extent,
merging in an even curve with the strongly convex anterior margin ; antero-dorsal
outline slightly concave. Escutcheon moderately wide, bordered by well-defined
ridges ; lunule somewhat excavated, not bordered. A rather obscure diagonal ridge
runs from the umbo to postero-ventral corner of shell. Ornament consisting of thin
concentric ridges which fade away at a variable distance from the umbo, so that
later growth-stages are smooth in all full-grown specimens ; ridges separated by
much broader intervals.

HOLOTYPE AND PARATYPES. Holotype, no. L.53322. There are also numerous
paratypes.

LOCALITY AND HORIZON. Tendaguru, Tanganyika ; excavation in Upper Kim-
meridgian, dinosaur beds.

REMARKS. The specimens are preserved in fine-grained buff-coloured sandstone.
The great amount of variation which they show appears to be largely due to original
differences in shape, although many have suffered distortion and compression in
fossilization. The species is not closely comparable to any previously described
from the Upper Jurassic. E. nortonensis (Cox) (1944) : 111, text-fig. 4c), from the
Lower Bathonian of England, is of about the same size as the East African species,
but differs in its cuneiform and more elongate shape.

Eomiodon namgaruensis sp. nov.
Pl. 18, figs. 14a, b

Di1aGnosis. Rather large for the genus (length of holotype 4g mm.), ovate-
cuneiform, inequilateral, height about four-fifths of length, beaks at anterior fifth
of length ; inflation strong. Umbo prominent, very broadly rounded, well incurved
to the strongly prosogyrous beak. Postero-dorsal outline pronouncedly parasigmoi-
dal, rather steep, forming an obtuse angle with the low, straight, oblique posterior
margin ; ventral margin strongly convex ; antero-dorsal outline strongly concave ;
anterior margin broadly convex. Escutcheon moderately wide, well impressed,
bordered by sharp ridges ; lunule broad, cordate, well impressed, smooth, also
bordered by a ridge in each valve. No distinct ridge runs from the beak to the

FROM TANGANYIKA AND KENYA 117

postero-ventral corner of the shell. Early growth-stages ornamented with narrow,
regular concentric ridges of which those farthest from the umbo are about I mm.
apart ; remainder of shell with only irregular concentric rugae.

HOLOTYPE AND PARATYPE. Holotype, no. LL.35146 ; one broken paratype.
Both ex B.P. Coll.

LOCALITY AND HORIZON. About 1 mile E.S.E. of Uleka, Mavudyi-Namgaru area,
Tanganyika ; Jurassic (stage uncertain).

REMARKS. The dimensions of this shell, which has the unmistakable external
characters of Eomiodon, exceed those of any previously known Jurassic species of the
genus, but are less than those of E. libanotica (Fraas) (Vokes, 1946 : 172, pl. 5, figs.
I-12, as Protocyprina libanotica) from the Aptian of the Lebanon.

Subgenus AFRICOMIODON nov.

Diacnosis. Well inflated, with anteriorly placed, prominent, strongly proso-
gyrous and incurved umbones. Escutcheon broader than in Eomiodon s.str. and
bordered by ridges which are not so well defined as in that group ; in each valve one
cardinal tooth (20 in the left, 35 in the right) is stoutly triangular, but remaining
cardinals only feebly developed. Anterior lateral (Aii) in left valve and posterior
lateral (Pi) in right valve strongly developed, remaining laterals weak.

TYPE SPECIES. Eomiodon (Africomiodon) cutleri sp. nov.

REMARKS. This new subgenus resembles Eomiodon s.str. in the general arrange-
ment of the hinge teeth and in the presence of evenly spaced concentric ridges which
are confined to earlier growth stages. It is distinguished by the very different shape
and strong inflation of the shell and by the weakness of all the teeth except the four
mentioned.

Eomiodon (Africomiodon) cutleri sp. nov.
Pl. 18, figs. 17, 18a, b

SPECIFIC NAME. After the late W. E. Cutler, the first leader of the British Museum
East Africa Expedition.

DiaGnosis. Shell of medium size, with characteristic asymmetrical outline due
to pronounced postero-dorsal angle and rather protruding, very anteriorly placed,
prosogyrous umbones ; height (20-5 mm. in holotype) slightly exceeding length in
most specimens. Postero-dorsal outline convex, gently sloping, forming rather pro-
nounced, obtuse angle with feebly convex posterior margin ; this merges into the
strongly and evenly convex ventral margin which is continued by the equally con-
vex anterior margin, the two forming almost a semicircle ; antero-dorsal outline
strongly excavated. The evenly spaced, well separated concentric ridges present
in early growth stages (where they are particularly prominent on the posterior part
of the surface) soon give way to the unevenly arranged concentric threads and rugae
which occupy the greater part of the surface. Dentition as described in the sub-

118 JURASSIC BIVALVIA AND GASTROPODA

generic diagnosis (the indistinctness of all the teeth except 20, 3a, Ail and Pi may be
partly due to the fact that it has been necessary to develop out the hinge region from
a hard limestone matrix in the specimens studied, but these teeth must have been
quite weak originally).

HOLOTYPE AND PARATYPES. Holotype, no. L.51995 ; numerous paratypes.

LOCALITIES AND HORIZONS. Tingutitinguti creek (type-locality) and Kipande,
Tendaguru, Tanganyika ; Upper Kimmeridgian, “ Tvigonia smeet’’ Bed. Scarp at
Kindope, N. of Tendaguru ; Upper Kimmeridgian, Nerinella Bed.

RemMARKS. Notwithstanding some external similarity to specimens from the
dinosaur beds of Tendaguru figured by Hennig (1914), pl. 14, figs. La—1) as Cyrena sp.,
the hinge structure of the shells now described differs considerably from that of the
two valves represented in Hennig’s pl. 14, figs. 2a, b. The form figured by Hennig
does not seem to be represented in the material examined by the present writer.
The Cyprina sp. of Dietrich (1933 : 46, pl. 8, fig. 125 ; pl. 11, fig. 147) seems to be
the Eomiodon dinosaurianum of the present memoir.

Superfamily TELLINACEA
Family TANCREDIIDAE Meek 1864
Genus TANCREDIA Lycett 1850

Tancredia sp. “ A”’
Pili ro} ig..2

MATERIAL. One specimen (no. L.93625).

LocALITY AND HORIZON. Korkai Hammassa, 19 miles E. of Takabba, N.E.
Kenya ; Oxfordian, Golberobe Beds.

DESCRIPTION. This specimen is the internal mould of the right valve of a moderate-
ly elongate Tancredia, 22:3 mm. long and 11 mm. high. The umbois slightly anterior
to mid-length, and just in front of it there is a slight concavity of the antero-dorsal
outline, which slopes at a rather gentle angle to the blunt anterior extremity of the
shell. It is close to the Tancredia from the Oxfordian of Cordebugle (Calvados)
figured by Chavan (1952, pl. 4, figs. 48-50) under the name Corbicella (Corbicellopsis)
autissiodorensis (Cotteau), but its anterior end is more tapering and sharply rounded
than in that species. It is also very similar to the English Bathonian species 7.
extensa Lycett, figured under the name T. axiniformis (Phillips) by Morris &
Lycett (1855 : 93, pl. 12, fig. 7; pl. 13, figs. 6a, 6), but its umbo is situated in a
slightly more anterior position.

Tancredia sp. ““B”
Pl 10) Be-.3

MATERIAL. One specimen (no. L.g3614).

LOCALITY AND HORIZON. Ogar Wein, 17 miles N.W. of Wergudud, N.E. Kenya ;
Oxfordian, Golberobe Beds.

FROM TANGANYIKA AND KENYA 119

DESCRIPTION. This specimen is the internal mould of the right valve of a moder-
ately elongate Tancredia, 20-5 mm. long and 11 mm. high. The umbo lies at about
the posterior two-fifths of the length, and the slightly concave antero-dorsal outline
slopes rather steeply to the abruptly rounded anterior extremity of the shell. The
specimen is very much like the English Bajocian and Bathonian species T. angulata
Lycett, as figured by Morris & Lycett (1855 : 94, pl. 12, fig. 8 ; pl. 13, figs. ga, 6).

Tancredia manderaensis sp. nov.
Bie 19, shies

DiaGnosis. Shell of medium size (length of holotype 22 mm., height 13 mm.),
moderately elongated, subequilateral. Antero-dorsal outline concave, sloping gently
to the rather sharply rounded anterior extremity of the shell. Ventral margin of
moderate convexity, the more strongly upcurved anteriorly. Posterior margin
weakly convex, slightly prosocline, forming an obtuse angle with the almost horizontal
postero-dorsal margin. Posterior diagonal ridge strong, delimiting a narrow, con-
cave posterior area.

Hototyre. No. LL.35190, consisting of the internal and external moulds of a
left valve. There is also a distorted specimen, possibly of the same species, in the
same piece of rock.

LOCALITY AND HORIZON. Matasafara, 15 miles W. of Mandera, N.E. Kenya ;
uppermost Jurassic, Gudediye Beds.

REMARKS. Compared with the “ Tancredia sp.A’’ of the Golberobe Beds (Oxfor-
dian) of N.E. Kenya and with the Tancredia from the Oxfordian of Cordebugle,
Calvados, France, figured by Chavan (1952 : 106, pl. 4, figs. 48-50) as Corbicella
(Corbicellopsis) autissiodorensis (Cotteau), this species is a little less elongated. It
is very close to the European Bathonian species 7. extensa Lycett, as figured (under
the name 7. axiniformis (Phillips)) by Morris & Lycett (1855, pl. 12, fig. 7 especially),
but has a more strongly convex ventral margin.

Family QUENSTEDTIIDAE Cox 1929
Genus QUENSTEDTIA Morris & Lycett 1855

Quenstedtia saggersoni sp. nov.
Ply 19) figs.) 45°6

SPECIFIC NAME. After Mr. E. P. Saggerson, of the Kenya Geological Survey.

Diacnosis. Of medium size, oblong, well elongated, with length (35 mm. in
holotype) exceeding twice the height ; only slightly inequilateral, with broadly
rounded, slightly protruding umbo just anterior to mid-length. Posterior margin
feebly convex, a little oblique in its general direction, joining the straight, parallel
postero-dorsal and ventral margins in even curves ; anterior margin strongly and
evenly convex.

120 JURASSIC BIVALVIA AND GASTROPODA

HOLOTYPE AND PARATYPE. Holotype, no. L.g3600. One paratype, no. L.g3636.

LOCALITIES AND HORIZON. Ogar Wein, 17 miles N.W. of Wergudud, N.E. Kenya
(type-locality) ; Korkai Hammassa, 19 miles E. of Takabba, N.E. Kenya ; both
Oxfordian, Golberobe Beds.

REMARKS. This species is rather closely comparable to Q. elongata Hudleston, an
English Oxfordian species figured by Arkell (19344 : 208, pl. 40, figs. 6, 7), but is not
quite so inequilateral. It is more elongate and less inequilateral than Q. laevigata
(Phillips), another Oxfordian species figured by Arkell (1934a : 296, pl. 40, figs. 4, 5).

Quenstedtia jouberti sp. nov.
PL. 19, fig. 5

1960. Quenstedtia sp ; Joubert, pl. ro, fig. tr.

SPECIFIC NAME. After Mr. P. Joubert, of the Kenya Geological Survey, collector
of the holotype.

Diacnosis. Moderately large for the genus (length of holotype 60 mm. +),
rather pronouncedly inequilateral ; umbones broadly rounded, projecting very
slightly above dorsal margins, and placed at anterior third of length. Postero-dorsal
margin straight, forming an obtuse angle with posterior margin, which merges with
ventral margin in a broad curve ; ventral margin straight, diverging slightly from
postero-dorsal margin in a posterior direction ; antero-dorsal outline moderately
excavated ; anterior margin (damaged in holotype) apparently evenly rounded.
An obtuse ridge runs from the umbo to the postero-ventral corner of the shell.

HototyPe. No. L.g2213. The only specimen.

LOCALITY AND HORIZON. N. of Figfirya, northern Raiya hills, N.E. Kenya ;
Upper Kimmeridgian, Dakacha Limestones.

REMARKS. This species is less elongate and more strongly inequilateral than Q.
gortani Venzo (1949 : 159, pl. 16, fig. 27), the most closely comparable of the five
representatives of the genus described by this author from the late Jurassic beds at
Cud Finagubi, in northern Kenya. It is much more inequilateral than the English
Portlandian species Q. portlandica Cox (1929 : 191, pl. 6, figs. 5, 6).

Superfamily MYACEA
Family CORBULIDAE Gray 1823
Genus CORBULA Bruguiere 1797

Corbula didimtuensis sp. nov.

Pl-x6,. figs. 10, 11a, 0; ¢

DiaGnosis. Moderately large for the genus (length of largest specimen 24 mm.),
subrectangular with a triangular tendency, very slightly inequilateral, not rostrate
posteriorly ; height two-thirds to three-quarters of length ; beaks slightly anterior

FROM TANGANYIKA AND KENYA 121

to median ; inequivalve, right valve larger but only slightly more inflated than left ;
most inflated part of each valve lying anterior to umbones. Right umbo rather
broadly rounded, prominent, higher than more narrowly rounded umbo of left valve ;
both are slightly incurved to the feebly prosogyrous beaks. Umbonal outline in
right valve rising slightly above the straight, gently inclined postero-dorsal margin,
which forms an acute angle with the slightly oblique posterior margin ; the latter
curves round below to merge with the straight or feebly convex ventral margin.
Antero-dorsal outline very feebly concave, steeply sloping ; anterior margin rounded,
feebly convex. In right valve a narrow and very shallow sulcus runs in some speci-
mens from the umbo to meet the ventral margin near its posterior extremity, while
a second narrow sulcus, scarcely perceptible, runs down the posterior slope from
behind the umbo to the point where the posterior and ventral margins meet. In
left valve a rounded-off anterior beak ridge is present in early growth-stages. There
is no impressed lunule in either valve. Both valves are ornamented with fine and
irregular concentric threads, and irregular concentric undulations may also be
present ; radial ornament lacking.

HOLOTYPE AND PARATYPES. Nos. LL.35073 and LL.35074-75 respectively, three
specimens in all.

LOCALITY AND HORIZON. Didimtu hill, 2 miles S. of Bur Mayo, N.E. Kenya ;
Upper Lias, Toarcian, Didimtu Beds.

Remarks. This large Corbula does not closely resemble any Jurassic species
hitherto described. It is rather like the well-known Eocene species C. gallica
Lamarck, differing in its flatter ventral margin and somewhat smaller size.

Corbula mandawaensis sp. nov.
Pl. 19, figs. 7a, b, 8a, b

Diacnosis. Of medium size for the genus (length of holotype 5-6 mm., of largest
specimen c. 9:0 mm.), trigonally ovate, rather strongly inequilateral, carinate but
not rostrate posteriorly, height two-thirds of length, beaks at anterior third to
quarter of length ; probably very slightly inequivalve (all specimens retaining both
valves in position have, however, suffered distortion by compression) ; inflation
moderate. In both valves, umbo broadly rounded, well incurved to the rather
strongly prosogyrous beak ; umbonal outline rising well above the straight, gently
inclined postero-dorsal margin, which forms an obtuse angle with the very oblique,
straight posterior margin ; ventral margin evenly and rather feebly convex ; antero-
dorsal outline slightly concave, steeply sloping ; anterior margin of moderate con-
vexity ; a well-marked, sigmoidal diagonal ridge delimits a flattened or concave
posterior area. Ornament consisting of fine, regular concentric threads present on
the flank but not on the posterior area.

HOLOTYPE AND PARATYPES. Holotype, no. LL.35148 ; several paratypes, in-

cluding nos. LL.35147, LL.35149, but many are imperfect or crushed. All ex B.P.
Coll.

122 JURASSIC BIVALVIA AND GASTROPODA

LOCALITY AND HORIZONS. Mandawa well no. 6, Tanganyika, at depths 46-48 feet
(holotype), 48-50 feet, 50-52 feet, 52-54 feet, 54-56 feet, 56-58 feet, 58-60 feet,
62-64 feet, 64-66 feet, 70-72 feet ; Bajocian (?).

REMARKS. In the two French Bajocian species C. aglaia d’Orbigny and C. alimena
d’Orbigny (tvpes figured by Thevenin, rgrza, pl. 26, figs. 34 and 36, 37 respectively),
which may be synonymous with one another, the truncated posterior end of the shell
is lower and the concentric ornament less regular than in the new species.

Corbula tanganyicensis sp. nov.
Pl: 19; figs: 9@,°b,/124,-b).¢).d

DiaGnosis. Rather small (length of largest specimen c. 5 mm.), trigonally ovate,
slightly inequilateral, some specimens subrostrate posteriorly, height two-thirds of
length, beaks situated between anterior third and middle of length ; very slightly
inequivalve, left valve slightly the lower, with its ventral margin overlapped by that
of right valve, but scarcely differing from the latter in its moderately strong inflation.
In both valves, umbo broadly rounded, well incurved to the rather strongly proso-
gyrous beak ; umbonal outline rising well above the straight, gently inclined, and
in some specimens relatively short postero-dorsal margin ; ventral margin strongly
convex anteriorly, flattened or sinuate posteriorly ; antero-dorsal outline slightly
concave, steeply sloping ; anterior margin of varying convexity ; a well-defined,
sigmoidal diagonal ridge delimits a concave posterior area. Ornament consisting of
fine, regular concentric riblets present on flank but not on posterior area.

HOLOTYPE AND PARATYPES. Holotype, no. LL.35150 ; several paratypes, in-
cluding no. LL.35151. All ex B.P. Coll.

LOCALITY AND HORIZONS. Mandawa well no. 7, Tanganyika, at depths 3760-3770
feet and 4510-4520 feet (holotype) ; Bajocian (?).

REMARKS. This species is smaller and slightly more gibbose than C. mandawaen-
sts, and also differs in its narrower, commonly rostrate posterior extremity and in its
rather coarser concentric ornament.

Corbula pindiroensis sp. nov.
Pl. 10, figs. 14a, b, c, 15a, b

DiaGnosis. Of medium size for the genus (length of largest specimen c. 13 mm.),
trigonally ovate, slightly to moderately inequilateral, not rostrate posteriorly, height
about two-thirds of length, beaks at anterior two-fifths to third of length ; rather
strongly inflated, apparently sub-equivalve (all specimens, however, have suffered
some distortion by compression). In both valves, umbo very broadly rounded, well
incurved to the moderately prosogyrous beak ; umbonal outline rising only slightly
above the feebly concave postero-dorsal outline, which forms a slightly obtuse angle
with the straight, low, slightly oblique posterior margin ; ventral margin of rather
strong convexity, straightened and upturned at its posterior end ; anterior margin

FROM TANGANYIKA AND KENYA 123

strongly convex ; antero-dorsal outline slightly concave ; a sharply angular,
sigmoidal diagonal ridge delimits a narrow, concave posterior area. Ornament of
strong, unequal, unevenly arranged concentric riblets and threads on flank, and finer
growth threads on posterior area.

HOLOTYPE AND PARATYPES. Holotype, no. LL.35152 ; about 16 paratypes, in-
cluding no. LL.35153, and mostly very imperfect. All ex B.P. Coll.

LOCALITY AND HORIZONS. Pindiro well no. 1, Tanganvika, at depths 162-166 feet,
166-170 feet (holotype), 170-174 feet, 174-178 feet, 178-180 feet, 194-198 feet,
250-254 feet ; Bajocian (?).

ReMARKS. This species does not closely resemble any corbulid previously
described from the Middle Jurassic. The English Bathonian form C. attenuata
Lycett (1863 : 62, pl. 37, figs. 6, 6a) is more elongate, with a broader and less prom-
inent umbo.

Corbula kidugalloensis sp. nov.
PR’ 16, figs? 174;'d,"c

DiaGnosis. Of medium size for the genus (length of holotype 11-2 mm.), pyriform,
with a short posterior rostrum, subequivalve, gibbose ; height equal to about three-
quarters of length. Umbones broadly rounded, prominent, almost median in
position, well incurved to the prosogyrous beaks. Lunular region well impressed.
Antero-dorsal outline slightly concave, sloping steeply to the evenly rounded anterior
end of the shell. Ventral margin asymmetrically and rather strongly convex, with
a small sinus (indicated by the growth-lines, this part of the actual margin being a
little imperfect) at the beginning of the pointed rostrum. Postero-dorsal outline
almost straight, sloping steeply ; posterior umbonal ridges weak, sigmoidally curved.
Ornament consisting in early stages of growth of regularly arranged, narrow concentric
riblets, separated by broader intervals ; in later growth-stages these are replaced by
irregular rugae.

HoLotyrPe. No. LL.35154, ex B.P. Coll. The only specimen.

LOCALITY AND HORIZON. Magole, 5 miles N.W. of Kidugallo, Tanganyika ;
Bajocian.

REMARKS. Its much larger size distinguishes this species from Corbula tangany-
icensis sp. nov., which is very similar in shape.

Corbula eamesi sp. nov.
Pl. 19, figs. 19a, b, c

SPECIFIC NAME. After Dr. F. E. Eames, Chief Palaeontologist of the British
Petroleum Co., Ltd.

Diacnosis. Of large-medium size for the genus, pyriform but not distinctly
rostrate posteriorly, length (16 mm.) exceeding one and a half times the height
(which may, however, have been somewhat reduced by distortion) ; fairly strongly

124 JURASSIC BIVALVIA AND GASTROPODA

inflated, subequivalve. Umbones broadly rounded, situated at about anterior third
of length, and well incurved to the prosogyrous beaks. Lunular region well im-
pressed. Antero-dorsal outline slightly concave, sloping steeply to the low, abruptly
rounded anterior end of the shell. Ventral margin asymmetrical, moderately con-
vex anteriorly, flattened posteriorly except at extreme end, which bends up sharply
to the angular posterior extremity of shell. Postero-dorsal outline moderately
convex except posteriorly, where the actual dorsal margin emerges from behind the
umbonal profile. Posterior margin short, straight, very oblique, forming obtuse
angle with postero-dorsal margin. Posterior umbonal ridges well defined, sigmoidal.
Ornament consisting of rounded concentric riblets separated by much narrower
intervals and regularly spaced in all stages of growth.

Hototyre. No. LL.35155, ex B.P. Coll. The only specimen.

LOCALITY AND HORIZON. 6 miles N.W. of Kidugallo, Tanganyika ; Bajocian.

REMARKS. In shape this species, with its gradual posterior taper, bears a very
slight resemblance to the German Bajocian species C. involuta Minster (in Goldfuss,
1840 : 250, pl. 151, figs. 14a, b), which needs re-describing on the basis of additional
material. It differs from Goldfuss’s type-specimen (re-illustrated by Kuhn, 1938 :
142, pl. 5, fig. 7), which is Io mm. long, in its larger size, its more elongate outline,
and its much stronger inflation.

Corbula asaharbitensis sp. nov.
Pl. 19, figs. 184, b

DiaGnosis. Rather small (length of holotype 5-5 mm.), subtrigonal, well elongated,
height about three-fifths of length ; inflation moderate ; whether equivalve or not
uncertain. Umbones not prominent, just posterior to mid-length, slightly opistho-
gyrous ; an umbonal ridge present in each valve, crossing shell to ventral margin
with slight posterior inclination. Posterior end of valves, beyond the umbonal ridge,
compressed and subrostrate, tapering to a narrow extremity and with slightly con-
cave dorsal margin and almost straight ventral margin. Antero-dorsal outline
feebly convex, gently sloping ; anterior margin evenly rounded, curved in continuity
with the ventral margin, which is strongly convex along the anterior half of its length.
Surface of shell anterior to the umbonal ridge ornamented with evenly spaced con-
centric ridges crossed by radial threads, forming a reticulate pattern ; posterior end
of shell ornamented with radial riblets only, about 8 in number. The ornament is
similar on the two valves.

HOLOTYPE AND PARATYPES. Holotype, no. LL.13230 ; several paratypes.

LOCALITY AND HORIZON. I mile N. of Asaharbito, N.E. Kenya ; Bathonian [? or
Callovian], Asaharbito Beds.

REMARKS. Before the more complete specimens had been extracted from the
matrix it was thought that this species might be related to the European Bathonian
form Corbula hulliana Morris, but it is much more elongate than that species and also
differs in the presence of radial ornament on both valves. It is a little like the Kim-

FROM TANGANYIKA AND KENYA 125

meridgian species Corbula vomer Contejean (1860 : 254, pl. 10, figs. 29, 30), but is
very much smaller and differs considerably in the direction of its umbonal ridge.

Corbula kailtaensis sp. nov.
Pl. 19, figs. 13a, b

Diacnosis. Of medium size for the genus (length of holotype 9-6 mm.), pyriform,
height two-thirds of length. Left (and only known) valve gibbose, with a short,
narrow posterior rostrum ; umbo broadly rounded, prominent, slightly anterior to
mid-length ; antero-dorsal outline very slightly concave, sloping steeply to the
broadly rounded anterior extremity of the shell ; ventral margin strongly convex,
symmetrical except for a broad, ill-defined sinus at the beginning of the posterior
rostrum ; postero-dorsal outline parasigmoidal ; no distinct umbonal ridge. Orna-
ment consisting of narrow and slightly unevenly spaced concentric riblets.

HoLotypPe. No. L.g2036. The only specimen.

LocaLITy AND HORIZON. Kailta, Golberobe hills, N.E. Kenya ; Oxfordian,
Golberobe Beds.

REMARKS. This species rather closely resembles Corbula buckmani Lycett (1863 :
63, pl. 37, fig. 8), from the Bathonian of England, but in that species there is an obli-
que posterior margin which forms an obtuse angle with the hinge-margin, and the
narrow posterior rostrum characteristic of the present form is lacking. C. glosensis
Zittel & Goubert (figured Chavan 1952, pl. 4, figs. 76-79), from the Upper Oxfordian
of Cordebugle, Calvados, France, is not so distinctly rostrate.

Superfamily PHOLADOMYACEA
Family PHOLADOMYIDAE Gray 1847
Genus PHOLADOMYA G. B. Sowerby 1823

Pholadomya reticulata Agassiz
Pl.20 iiss, 2
1842. Pholadomya reticulata Agassiz : 80, pl. 4, figs. 4-6 ; pl. 4c, figs. 1-4.
1874. Pholadomya reticulata Ag. ; Moesch: 28, pl. 9, figs. 2, 4,5, 9-II.

1893. Pholadomya reticulata Ag. ; Choffat : 11, pl. 4, figs. 4-7.
1929. Pholadomya reticulata Ag. ; Lanquine : 203, pl. 7, fig. 8.

MATERIAL. Three specimens (nos. LL.35076-78).

LOCALITY AND HORIZON. Didimtu hill, 2 miles S. of Bur Mayo, N.E. Kenya ;
Upper Lias, Toarcian, Didimtu Beds.

REMARKS. The largest specimen, the original length of which was slightly more
than 25 mm., is much eroded, but the smaller specimen illustrated is ornamented with
rather coarse concentric folds crossed by narrow radial riblets which are present on
all parts of the shell. There is close agreement with the illustrations cited above.
This relatively small Pholadomya was originally described from beds of Upper Liassic
age. Its range extends, according to Moesch, into the Bajocian.

126 JURASSIC BIVALVIA AND GASTROPODA

Pholadomya lirata (J. Sowerby)
Pls2o; hers

1818a. Cardita? livata J. Sowerby : 220, pl. 197, fig. 3.

1910. Pholadomya carvinata Goldfuss ; Dacqué : 31, pl. 5, fig. 7.
1916. Pholadomya carinata Goldfuss ; Douvillé : 55, pl. 6, fig. 8.
1935a. Pholadomya livata (J. Sowerby) ; Cox : 190, pl. 21, figs. 8, 9.
1939. Pholadomya carinata Goldtuss ; Stefanini: 259, pl. 27, fig. 2.
1948. Pholadomya livata (J. Sowerby) ; Cox & Arkell : 43.

1960. Pholadomya lyrata J. de C. Sowerby ; Joubert, pl. 11, fig. 6.

MATERIAL. Several specimens.

LOCALITIES AND HORIZONS. Kidugallo Station and 11} miles to the east, Central
Railway, Tanganyika ; Bajocian, Station Beds. 2 miles E. of Magindu Station,
Central Railway, Tanganyika ; Callovian. 3 miles W. of Melka Biini, N.E. Kenya ;
Callovian, Rukesa Shales.

REMARKS. This widespread species was discussed by me in 1935. The earlier
authors who recorded it from East Africa cited it under the name P. carinata Gold-
fuss.

Pholadomya ovalis (J. Sowerby)
Pl. 20; tig. 1

1819a. Lutvaria ovalis J. Sowerby : 47, pl. 226, fig. 1 only.

1842. Pholadomya ovulum Agassiz : 119, pl. 3, figs. 7-9 ; pl. 3b, figs. 1-6.

1874. Pholadomya ovulum Agassiz ; Moesch : 48, pl. 20, figs. 1-11.

1910. Pholadomya angustata (Sow.) ; Dacqué: 32, pl. 5, fig. 8 (non Sowerby sp.).
1929. Pholadomya protei (Brongniart) ; Weir : 33, pl. 3, fig. 10 (non Brongniart sp.).
1948. Pholadomya ovalis (J. Sowerby) ; Cox & Arkell: 44.

1960. Pholadomya ovalis (J. Sowerby) ; Joubert, pl. 11, figs. 8a, b.

MATERIAL. Two specimens (nos. L.g8277, L.92075).
LOCALITIES AND HORIZONS. Hagardulun, 25 miles N.E. of Tarbaj, N.E. Kenya ;

Bathonian—Callovian, Bur Mayo Limestones. Kulong, 2 miles S.W. of Muddo Erri,
N.E. Kenya ; Callovian [?-Lower Oxfordian|, Muddo Erri Limestones.

Pholadomya protei (Brongniart)

1821. Cardium protei Brongniart : 554, pl. 7, figs. 7a~-c.

1872. Pholadomya protei (Brongniart) ; de Loriol : 169, pl. to, figs. 13-15.

1875. Pholadomya protei (Brongniart) ; Moesch : 79, pl. 30, figs. 1, 2.

1935a Pholadomya protei (Brongniart) ; Arkell : 333, pl. 46, figs. 8,9 ; pl. 47, figs. 1-4.
1939. Pholadomya protei (Brongniart) ; Stefanini: 263, pl. 27, figs. 6-8.

MATERIAL. One specimen (no. LL.11807).

LOCALITY AND HORIZON. Just W. of Mabokweni, 4 miles N.W. of Tanga, Tan-
ganyika ; Kimmeridgian.

REMARKS. This species, which has been misidentified by some authors, is
characterized by its relatively short outline and by its small number (3-6) of costae,

FROM TANGANYIKA AND KENYA 127

which are closely arranged on the middle of the shell, the most anterior one standing
out as a sharp keel. Although its posterior end is broken away, the specimen now
recorded seems to be a very typical example of the species. The specimens from
Somaliland figured as P. prote by Dacqué (1905 : 140, pl. 15, figs. 1-3) and one from
Rukesa, N. Kenya, considered by Weir (1929 : 33, pl. 3, fig. 10) to be a young indi-
vidual of the species, were wrongly identified.

Pholadomya hemicardia Roemer
Pl. 20, fig. 5

1836. Pholadomya hemicardia Roemer : 131, pl. 9, fig. 18.

1874. Pholadomya hemicardia Roemer ; Moesch : 58, pl. 23, figs. 1-6; pl. 24, fig. 11.
1935a. Pholadomya hemicardia Roemer ; Arkell: 336, pl. 46, figs. 5-7.

1960. Pholadomya hemicardia Roemer ; Joubert, pl. 11, figs. 5a, b.

MATERIAL. Two specimens (nos. L.g2186, LL.35156).

LOCALITIES AND HORIZONS. Mandawa-—Lonji creek traverse, Mandawa area, Tan-
ganyika ; Upper Oxfordian. Hegalu hills, 2 miles N. of Finno, N.E. Kenya ;
Upper Kimmeridgian, Dakacha Limestones.

REMARKS. The more complete specimen is 33 mm. long, with the posterior end
of the shell rather angular and situated above mid-height. The ornament consists
of weak, irregular concentric undulations crossed by weak radial riblets, which are
scarcely perceptible on the posterior part of the surface. The specimens appear to
fall within the range of variation of P. hemicardia, which in Europe occurs in the
Oxfordian and Kimmeridgian.

Genus HOMOMYA Agassiz 1843

Homomya inornata (J. de C. Sowerby)

1840b. Pholadomya? inornata J. de C. Sowerby : 327, pl. 21, fig. 8.

1874. Pholadomya inornata Sowerby ; Moesch : 53.

1907a. Pholadomya inornata Sowerby ; Cossmann: 134, pl. 1, fig. 17.

1912. Pholadomya inornata Sowerby ; Lissajous : 92, pl. 11, fig. 21.

1921. Pholadomya inornata Sowerby ; de la Bouillerie : 35, pl. 4, fig. ro.

1924. Pholadomya (Flabellomya) ovulum Agassiz ; Cossmann : 53, pl. 7, figs. 3-8 (non Agassiz).

MATERIAL. One specimen (no. L.g2154).

LOCALITY AND HORIZON. 34 miles W. of Melka Biini, N.E. Kenya. Callovian,
Rukesa Shales.

REMARKS. This species, which is ornamented with concentric ribs undulating
slightly in places and may also bear a few faint radial threads (actually just visible
on Sowerby’s holotype), was described originally from the Callovian of India. It
has been recorded by authors cited above from the Callovian of France. Cossmann
(1924), however, has suggested that the French specimens would be more correctly
identified as Pholadomya ovulum Agassiz (= P. ovalis (J. Sowerby)). This view is

128 JURASSIC BIVALVIA AND GASTROPODA

not here accepted. Although radial ornament is relatively weak and variable in
P. ovalis, it is more distinct than in any specimens which have been recorded as P.
tnornata, a species which it seems preferable to include in Homomya. The African
fossil now recorded is imperfect, but agrees well with typical specimens from India.

Homomya rahmuensis sp. nov.
Pl. 20, figs. 3a, b

1960. Homomya sp. nov. ; Joubert, pl. 11, figs. ga, b.

DiaGnosis. Small for the genus (length of holotype 43 mm.), oblong-ovate,
height about three-fifths of length ; inflation moderate (22 mm. in holotype) and
even, greatest at about mid-length ; posterior gape narrow. Umbones rather
narrow, protruding only slightly, placed at about the anterior fifth of the length ;
posterior umbonal ridge, bordering a rather broad but shallow escutcheon, ill-defined
except near the umbones. Postero-dorsal and ventral margins straight, elongate,
sub-parallel. Posterior margin of feeble convexity, sub-vertical in its general direc-
tion. Ornament consisting of weak, irregular concentric folds.

HoLotyPe. No. L.g2260. The only specimen.

LOCALITY AND HORIZON. Uacha, 6 miles S. of Rahmu, N.E. Kenya. Oxfordian,
Rahmu Shales.

REMARKS. This species is comparable to H. censoriensis (Cotteau) (Peron, 1906 :
43, pl. 1, fig. 1), Oxfordian of France, but is not so high at its posterior end. 4H.
corallina de Loriol (1894a : 80, pl. 6, figs. I, 1a), Lower Kimmeridgian of France, is
more gibbose and slightly less elongate.

Homomya hortulana Agassiz
Pl20, figw4

1843. Homomya hortulana Agassiz : 155, pl. 15.

1872. Pholadomya hortulana (Agassiz); de Loriol : 166, pl. 10, fig. 16.

1893. Pholadomya (Homomya) hortulana (Agassiz) ; Choffat : 33, pl. 9, figs. 2-6,
1933. Homomya cf. hortulana Agassiz ; Dietrich : 55, pl. 7, fig. 104.

MATERIAL. ‘Three specimens.

LOCALITIES AND HORIZONS. N. of Kipande, Tendaguru, Tanganyika ; Upper
Kimmeridgian, Nerinella Bed. Mtapaia road, Tendaguru ; Upper Kimmeridgian,
“ Trigoma smeei’”’ Bed.

REMARKS. The prominence of the umbones varies considerably in European speci-
mens of this species. They are very broad and depressed in the East African speci-
mens now recorded, but these can be matched with published figures of specimens
from Europe, and it seems unnecessary to follow Dietrich in qualifying their specific
identification.

FROM TANGANYIKA AND KENYA 129

Genus GONIOMYA Agassiz 1841

Goniomya trapezicostata (Pusch)
PL, 21, tis, 2, 3

1836. Lutvaria tvapezicostata Pusch : 80, pl. 8, figs. 10a—c.

1840. Lysianassa ornata Miinster ; Goldfuss : 264, pl. 154, fig. 12.

1842. Goniomya inflata Agassiz : 20, pl. 1, fig. 15.

1852. Pholadomya trapezina Buvignier : 8, pl. 8, figs. 14-18.

1900. Goniomya cf. trapezina (Buvignier) ; Miiller : 536, pl. 18, figs. 2, 2a.
1924. Goniomya trapezicostata (Pusch) ; Cossmann : 51, pl. 7, figs. 9, 10.

MATERIAL. Two specimens (nos. L.54080, LL.35157), the second ex B.P. Coll.

LOCALITIES AND HORIZONS. I} miles E. of Kidugallo Station, Central Railway,
Tanganyika. Bajocian. 4mile N.W. of bridge over Mkulumuzi river, 2 miles W. of
Tanga, Tanganyika ; Callovian.

REMARKS. In this species the steep oblique ribs on the anterior and posterior
parts of the surface are separated in all stages of growth by a horizontal rib, instead
of meeting to form a series of V’s, as in most species of the genus. In the specimen of
Bajocian age now recorded the intervening horizontal ribs are shorter than in the
Callovian specimen, which agrees better with the typical G. trapezicostata. The
difference, however, does not seem important enough to justify its specific separation.
In Europe G. trapezicostata occurs in the Callovian and Oxfordian.

Goniomya literata (J. Sowerby)

1819a. Mya? literata J. Sowerby : 45, pl. 224, fig. 1.

1819a. Mya v. scripta J. Sowerby : 46, pl. 224, figs. 2-5.

1935a. Goniomya literata (Sowerby) ; Arkell : 344, pl. 48, figs. 1-7.
1939. Goniomya litevata (Sowerby) ; Stefanini: 254, pl. 26, figs. 3a, d.

MATERIAL. One specimen (no. LL.16846).

LOCALITY AND HORIZON. Scarp face, eastern margin of Makoko plain, Bagamoyo
hinterland, Tanganyika ; Oxfordian.

REMARKS. In this specimen the convergent oblique ribs almost die out at mid-
growth, particularly on the posterior part of the surface. In this respect the speci-
men agrees with G. marginata Agassiz, as interpreted by de Loriol (1872 : 187, pl. 12,
figs. 3, 4) and Boden (1911 : 58, pl. 6, figs. 2, 2a), although it is to be noted that
Agassiz’s (1842, pl. 1, figs. 12-14 ; pl. Ic, fig. 15) original figures of G. marginata do
not show this fading away of the ribs. Arkell (1935a : 346) was of the opinion that
G. marginata, even as interpreted by the authors cited, is inseparable from G. literata.

Genus OSTEOMYA Moesch, 1874

Osteomya dilata (Phillips)

1829. Mya dilata Phillips: 155, pl. 11, fig. 4.
1855. Myacites dilatus (Phillips) ; Morris & Lycett : 114, pl. 10, figs. 5a, b.

130 JURASSIC BIVALVIA AND GASTROPODA

1923. Goniomeris dilatata (Phillips ); Lissajous : 195, pl. 32, figs. 2-5.
1948. Osteomya dilata (Phillips) ; Cox & Arkell: 45.

MATERIAL. Two specimens (nos. LL.11566-—7).

LocALITy AND HORIZON. Kidugallo Station, Central Railway, Tanganyika.
Bajocian, Station Beds.

REMARKS. Although distorted, the specimens now recorded are unmistakable
examples of this species. Its range in Europe is from Bajocian to Callovian. It
has been recorded from the Bajocian of Madagascar, but not from East Africa pre-
viously.

Family MYOPHOLADIDAE Cox 1964
Genus MYOPHOLAS Douvillé 1907

Myopholas manderaensis sp. nov.
Pl? 19) 1125-20

1960. Myopholas sp. nov. : Joubert, pl. 11, fig. ro.

Diacnosis. Rather small for the genus, elongate-ovate, with the length (31 mm.
in the holotype) about 2} times the height (12 mm.). Inflation only moderate, but
possibly diminished in the course of fossilization. Umbo very broadly rounded,
placed at about the anterior third of the length, and not protruding above the postero-
dorsal margin, which slopes gradually towards the narrowly rounded posterior extre-
mity. Ventral margin with a broad and very shallow median sulcus. Ornament of
anterior two-thirds of surface consisting of 23 narrow radial ribs, the most anterior
three of which are separated by relatively broad intervals and the remainder by much
narrower ones. The most posterior of these ribs stands out slightly more prominent-
ly than the others ; the posterior third of the surface, lying beyond it, bears a few
ribs which are just visible in the earlier growth-stages and then fade away partly or
completely, leaving the surface almost smooth.

HorotypPeE. No. L.g2271, the external mould of a right valve. There are also
two very imperfect specimens.

LOCALITY AND HORIZON. Matasafara, 15 miles W. of Mandera, N.E. Kenya ;
uppermost Jurassic, Gudediye Beds.

REMARKS. The virtual absence of ribbing on the posterior third of the surface
distinguishes this species from the European Upper Jurassic forms Myopholas mul-
ticostata (Agassiz) and M. percostata Douvillé (Douvillé, 19078, pl. 2, figs. 6, 7 and
figs. 4, 5 respectively) and is more suggestive of the Neocomian shell M. semicostata
(Agassiz) (Douvillé, 1907), pl. 2, fig. 8), which, however, has fewer costae on the
anterior part of its surface.

FROM TANGANYIKA AND KENYA 131
Family PLEUROMYIDAE Dall 1900
Genus PLEUROMYA Agassiz 1845

Pleuromya didimtuensis sp. nov.
Pie x0, fies16

Diacnosis. Of small-medium size (length of largest specimen c. 24 mm.), sub-
ovate, somewhat projecting postero-dorsally and with subrostrate anterior end ;
inequilateral, height about two-thirds of length, beaks at anterior third of length ;
shell well inflated mesially, but somewhat compressed postero-dorsally. Umbones
broadly rounded, well incurved to the beaks, which are moderately prosogyrous.
Postero-dorsal margin feebly convex, subhorizontal, forming a slightly acute angle
with the backward-sloping posterior margin ; ventral margin strongly convex
posteriorly, where it joins the posterior margin, flattened and slightly convergent
with the postero-dorsal outline anteriorly ; antero-dorsal outline feebly concave,
steeply sloping ; anterior margin low, strongly convex. Ornament consisting of
narrow, rounded concentric ribs, a little sinuous and irregular in places. Internal
characters not observable.

HOLOTYPE AND PARATYPES. Nos. LL.35079 and LL.35080-81 respectively, three
specimens in all.

LOCALITY AND HORIZON. Didimtu hill, 2 miles S. of Bur Mayo, N.E. Kenya ;
Upper Lias, Toarcian, Didimtu Beds.

REMARKS. Owing to erosion the specimens do not clearly show the projecting
postero-dorsal corner of the shell, which is one of its most distinctive characters, but
this can be restored by studying the growth-lines. In this feature the present species
resembles Pteromya tater (Richardson & Tutcher) (1916 : 52, pl. 8, figs. 3a—-c), from
the basal Hettangian of England, but that species is larger and has a more strongly
convex ventral margin.

Pleuromya uniformis (J. Sowerby)
Pi 20, ue. 6

_ 1813a. Unio uniformis J. Sowerby : 83, pl. 33, fig. 4.

1900. Pleuromya tellina Agassiz ; Miiller : 536, pl. 18, figs. 3-5.

_ 1914). Pleuromya tellina Agassiz ; Hennig : 168, pl. 14, fig. 5.

1935a. Pleuromya untformis (J. Sowerby) ; Arkell : 325, pl. 45, figs. 1-13.
1948. Pleuromya uniformis (J. Sowerby) ; Cox & Arkell: 4o.

MATERIAL. Several specimens.

LOCALITIES AND HORIZONS. Scarp face, eastern margin of Makoko plain, Baga-
moyo hinterland, Tanganyika ; Oxfordian. Kinjele, 5 miles W. of Mtapaia, N. of
| Tendaguru, Tanganyika ; Upper Kimmeridgian, Indogrammatodon bed.

132 JURASSIC BIVALVIA AND GASTROPODA

Pleuromya calceiformis (Phillips)
Pl. 20, fig. g

1829. Mya calceiformis Phillips : 155, pl. 11, fig. 3.
1863. Mvyacites calceiforymis (Phil.); Lycett : 80, pl. 42, figs. 1, 1a.
1934a. Pleuromya calceiformis (Phil.) ; Arkell : 324, pl. 44, figs. 12, 12a.

MATERIAL. One specimen (no. LL.35158), ex B.P. Coll.

LOCALITY AND HORIZON. Mandawa-—Lonji creek traverse, Mandawa area, Tangan-
yika ; Upper Oxfordian.

REMARKS. The specimen now recorded is in every way typical of the species.
This has not been recorded previously from East Africa or from anywhere in the
Indian Ocean region.

Family CERATOMYIDAE Arkell 1934
Genus CERATOMYA Sandberger 1864

Ceratomya tanganyicensis sp. nov.
Pl. an; figs. 1¢@, 66

Diacnosis. Of medium size (length 41 mm.), ovate with a trigonal tendency,
moderately inequilateral, height four-fifths of length, beaks at about anterior third
of length ; shell well inflated mesially, somewhat compressed posteriorly. Umbones
very broadly rounded, not prominent, well incurved to the beak, which was apparent-
ly not strongly prosogyrous for the genus, but is obscured in the only available speci-
men. Postero-dorsal outline very feebly convex, rather steeply sloping, joining the
fairly sharply rounded posterior margin in an even curve ; ventral margin very
strongly convex anteriorly, almost angular posteriorly, where it bends up to the
narrowly rounded anterior end of the shell ; antero-dorsal outline very feebly con-
cave. Ornament of numerous narrow, rounded, subequal concentric ribs, which
number rather more than 20 to the cm.

HototyPe. No. LL.35159. The only specimen.

LOCALITY AND HORIZON. Lihimaliao creek, at a point near Mbaru creek, Man-
dawa area, Tanganyika ; Bajocian (?), Pindiro Shales.

Remarks. The closeness of the concentric ribbing distinguishes this from all other
post-Liassic species of the genus. In C. madagascariensis (Thevenin) (19080 : 28,
pl. 3, figs. 9, 9a), from the Upper Lias of Madagascar, the shell is higher and less
elongated.

Ceratomya concentrica (J. de C. Sowerby)
Pl).20; fig. 7
1825a. Isocardia concentrica J. de C. Sowerby : 147, pl. 491, fig. 1.

1855. Isocardia concentrica Sowerby ; Morris & Lycett : 108, pl. 10, figs. 3a, b (non pl. 15,
figs. 2a, b).

FROM TANGANYIKA AND KENYA 133

1863. Cevomya concentrica (Sowerby) ; Lycett, pl. 36, fig. 5.
1948. Cevatomya concentrica (Sowerby) ; Cox & Arkell: 41.
1960. Cevatomya concentrica (Sowerby) ; Joubert, pl. ro, figs. ga, b.

MATERIAL. About four specimens.

LOCALITIES AND HORIZONS. 3% miles W. of Melka Biini, N.E. Kenya ; Callovian,
Rukesa Shales. Kulong, 2 miles S.W. of Muddo Erri, N.E. Kenya ; Callovian [?-
Lower Oxfordian], Muddo Erri Limestones.

Remarks. In the specimens on which the ornament is best preserved the con-
centric ribs are numerous and closely arranged, as in specimens from the Great Oolite
of England. There is also an imperfect specimen from the Bajocian of Kidugallo,
Tanganyika, which seems to be very similar to C. concentrica but is more coarsely
ribbed. This may perhaps belong to the related species C. bajociana (d’Orbigny).

Ceratomya pittieri (de Loriol)
Pl. 2x, fig. 4

1883. Cevomya pittieri de Loriol : 25, pl. 6, figs. 3, 4.
1910. Cevomya concentrica (Sow.) ; Dacqué : 33, pl. 5, fig. 6 only (non Sowerby sp.).

MATERIAL. One specimen (no. LL.35160), ex B.P. Coll.

LOCALITY AND HORIZON. Magindu, Central Railway, Tanganyika ; Callovian.

REMARKS. This specimen, which is 94 mm. long, is a well elongated Ceratomya
with an almost terminal, only slightly protruding umbo which is strongly incoiled to
the beak. A slight radial depression of the flank appears at mid-growth and termin-
ates at the ventral margin near its anterior end. The ventral margin diverges
gradually from the hinge-margin in a posterior direction. The surface ribs, although
partly obliterated by erosion in places, can be seen to be regularly concentric and
fairly closely arranged.

Except for the presence of the radial depression, the shape of the shell agrees with
de Loriol’s figures of C. pittieri, the type specimens of which came from the Callovian
Mytilus Beds of the Alps of Vaud, Switzerland. The Abyssinian Kimmeridgian (?)
species C. paucilirata (Blanford), especially as figured by Futterer (1897, pl. 22,
fig. 1) also resembles the present specimen in shape, but its concentric ribs are not so
closely arranged. These forms are very close to de Loriol’s (1872, pl. 12, fig. 13)
“var. cylindrica’ of C. excentrica, an Upper Oxfordian-Kimmeridgian species highly
variable in form and ornament. In view of the Callovian age of the specimen now
recorded, however, it seems most satisfactory to identify it as C. pittiert.

Ceratomya wimmisensis (Gilliéron)

1883. Cevomya concentrica (Sowerby) ; de Loriol: 18, pl. 5, figs. 1-5 (non J. de C. Sowerby
sp.).

1886. Cevomya wimmisensis Gilliéron : 141.

1918. Ceromya wimmisensis Gilliéron ; Gerber : 12, pl. 1, figs. 3-6.

1929. Cevatomya wimmisensis (Gilliéron) ; Weir : 31, pl. 3, fig. 2.

134 JURASSIC BIVALVIA AND GASTROPODA

1929. ?Cevatomya cf. wimmisensis (Gilliéron) ; Weir : 31, pl. 3, fig. 1.
1935a. Cevatomya wimmisensis (Gilliéron) ; Cox : 186, pl. 20, figs. 6a, b.
1939. Ceratomya wimmisensis (Gilliéron) ; Stefanini: 248, pl. 25, figs. 5, 6.

MATERIAL. One specimen (no. L.83881).

LOCALITY AND HORIZON. 14 miles W.S.W. of Rahmu, N.E. Kenya. Callovian
[?-Lower Oxfordian], Muddo Erri Limestones.

REMARKS. This specimen shows the abrupt discordancies in ribbing characteristic
of this species, patches of oblique ribs occupying parts of the surface and concentric
ribs the remainder. The arrangement of the ribbing is altogether dissimilar on the
two valves. The specimen is not well enough preserved for illustration.

Ceratomya wilderriensis sp. nov.
Plaats

1960. Cevatomya excentrica (Roemer) ; Joubert, pl. 11, fig. 1 (nom Roemer sp.).

DiaGnosis. Shell moderately large (length of holotype c. 87 mm.), ovate, with
height about three-quarters of length, strongly inequilateral, evenly and moderately
strongly inflated. Umbo terminal, strongly prosogyrous and incurved, its outline
continuous with postero-dorsal outline of shell, which rises slightly above it before
curving gently down to meet the evenly convex posterior margin. Ventral margin
moderately and evenly convex. Umbonal ridges absent. Ornament consisting of
closely and fairly evenly arranged, rounded concentric ribs (about 8 to the cm. on
middle of shell), separated by narrower intervals.

HOLOTYPE AND PARATYPE. Nos. L.g2226 and L.g2246 respectively, two speci-
mens in all.

LOCALITIES AND HORIZON. Dussé, 14} miles S.E. of Rahmu, N. Kenya (type-
locality). Wilderri hill, 11 miles S.S.W. of Rahmu. Both Upper Oxfordian, Seir
Limestones.

REMARKS. This species, with its purely concentric ornament, belongs to the group
of Ceratomya concentrica (J. de C. Sowerby), differing from that species in the termin-
al position of its umbo, in the even convexity of its surface (the postero-dorsal region
is not in the least pinched-in), and in its larger size. In C. paucilivata (Blanford)
(1870 : 203, pl. 8, fig. 6 ; also Futterer 1897 : 610, pl. 22, fig. 1), Upper Jurassic of
S. Abyssinia, the umbo is more prominent and less anteriorly placed, the postero-
dorsal region is not so evenly convex, and the concentric ribs are broader. In C.
egerkingensis (Gerber) (1918 : 6, pl. 1, fig. 1), Lower Kimmeridgian of Switzerland,
the umbo is much more prominent and less anteriorly placed.

FROM TANGANYIKA AND KENYA 135

Ceratomya excentrica (Roemer)
Pl20} fig. 1

1836. Isocardia excentrica Voltz MS. ; Roemer: 106, pl. 7, figs. 4a—c.

1842. Ceromya excentrica (Voltz) ; Agassiz: 28, pls. 8a—c.

1897. Cevromya excentrica (Voltz) ; Agassiz ; Futterer : 608, pl. 22, figs. 2, 2a.

1929. Cevatomya excentrica (Weir) (sic) ; Weir: 31, pl. 3, fig. 4.

1934a. Cevatomya excentrica (Roemer) ; Arkell : 316, pl. 43, figs. 11, 12.

1939. Cevatomya excentrica (Voltz) ; Stefanini: 249, pl. 25, fig. 7.

1960. Cevatomya excentrica (Roemer) ; Joubert, pl. Io, figs. 10a, b (non pl. 11, fig. 1).

MATERIAL. Several specimens.

LOCALITIES AND HORIZONS. Hereri river crossing, 3 miles S. of Melka Kunha,
N.E. Kenya ; Kimmeridgian, Hereri Shales. 1 mile S.S.W. of Melka Dakacha,
N.E. Kenya ; Upper Kimmeridgian, Dakacha Limestones.

REMARKS. The specimens now recorded are typical in every way, showing coarse
ribs with various degrees of obliquity.

Superfamily PANDORACEA
Family THRACIIDAE Stoliczka 1870
Genus THRACIA Leach 1823

Thracia lens (Agassiz)
Plizn fig. 6

1845. Corimya lens Agassiz : 267, pl. 36, figs. I-15.
1912. Corymya lens Ag. ; Lissajous : 103, pl. 12, fig. 21.
1926. Thvracia aff. lenti Ag. ; Schmidtill : 82, pl. 11, figs. 20a, b.

MATERIAL. One specimen (no. LL.35161), ex B.P. Coll.

LOCALITY AND HORIZON. Lihimaliao creek, at a point near Mbaru creek, Mandawa
area, Tanganyika ; Bajocian (?), Pindiro Shales.

REMARKS. This specimen, which is about 28 mm. long, agrees well with the
original figures of the species in its elliptical outline, its broadly rounded, depressed
umbo lying well posterior to mid-length, its evenly convex, gently sloping postero-
dorsal outline, and its evenly concave, gently sloping antero-dorsal outline. The
right valve is crushed. This species was originally described from the Bajocian of
Switzerland and has been recorded from the Bathonian of France, Germany, and
Sardinia.

Thracia viceliacensis d’Orbigny
Ply 25, fig. 0

1850a. Thracia viceliacensis d’Orbigny : 306.

1906. Thyracia viceliacensis d’Orb. ; Cossmann : 288, pl. 2, figs. 14-19.
1911a. Thracia viceliacensis d’Orb. ; Thevenin : 134, text-fig.

1911. Thvracia viceliacensis d’Orb. ; Flamand : 903, pl. 11, figs. 174, b.

136 JURASSIC BIVALVIA AND GASTROPODA

1912. Thyvracia viceliacensis d’Orb. ; Lissajous : 102, pl. 12, fig. 20.
1916. Thvracia viceliacensis d’Orb. ; Douvillé : 56, pl. 6, fig. 9.

1925. Thvracia viceliacensis d’Orb. ; de la Bouillerie : 89, pl. 9, fig. 4.
1935a. Thracia viceliacensis d’Orb. ; Cox: 190, pl. 20, fig. 5.

1939. Thvracia viceliacensis d’Orb. ; Stefanini: 266, pl. 27, figs. 9, Io.

MATERIAL. One specimen (no. LL.35162), ex B.P. Coll.

LOCALITY AND HORIZON. Lonji creek, W. of Mandawa, Tanganyika ; Callovian.

REMARKS. This specimen, which is 36 mm. long, is in every way typical of T.
viceliacensis, a species characterized by its prominent, obtusely angular, submedian
umbones and not very elongated form. The species was originally described from the
Bathonian of France and has been recorded from beds attributed to that stage in
Algeria and Sinai as well asin Europe. In British Somaliland, however, it has been
found in beds regarded as Callovian. A specimen from beds of doubtful but possibly
post-Callovian age at Dakatch, Italian Somaliland, attributed by Weir (1929 : 34,
pl. 3, fig. 19) to T. viceliacensis is not so tall and trigonal as typical specimens of the
species and may belong to a distinct form.

Superfamily POROMYACEA
Family CUSPIDARIIDAE Dall 1886
Genus CUSPIDARIA Nardo 1840

Cuspidaria ayersi sp. nov.
Pll 21> figs. 64, 05-74, 0

SPECIFIC NAME. After Mr. F. M. Ayers, of the Geological Survey of Kenya.

Dracnosis. Shell of small-medium size (length of holotype 10-3 mm.), slightly
longer than high, subalate posteriorly. Left (and only known) valve strongly in-
flated, with very prominent and narrowly rounded umbo situated just anterior to
mid-length and strongly incurved to the prosogyrous beak. Anterior margin
strongly convex, curved in continuity with ventral margin, the anterior part of which
has a shallow sinus in some specimens. Posterior wing of feeble convexity, rounded
at its tip, which is level with or extends to a variable extent beyond the posterior
extremity of the ventral margin ; wing separated from inflated body of valve by
radial sulcus to which there corresponds a sinus of posterior margin. Ornament
consisting of regularly arranged concentric ribs absent from posterior wing in some
specimens.

HOLOTYPE AND PARATYPES. Holotype, no. LL.13246. About 15 paratypes.

LOCALITY AND HORIZON. I mile N. of Asaharbito, N.E. Kenya ; Bathonian [? or
Callovian], Asaharbito Beds.

REMARKS. In this species the ventral margin extends further in a posterior
direction than in the European Kimmeridgian species Cuspidaria fontannesw (de

FROM TANGANYIKA AND KENYA 137

Loriol) (1878 : 141, pl. 22, figs. 2, 3) or in the two Tithonian species C. picteti (Zittel)
(1870 : 118, pl. 12, fig. 7) and C. tvansylvanica (Neumayr) (1873 : 205, pl. 43, fig. 5) ;
in consequence, the posterior margin has a well-defined sinus. These are the two
most closely comparable species described previously.

Class GASTROPODA Cuvier
Subclass PROSOBRANCHIA Milne Edwards
Superfamily EUOMPHALACEA
Family EUOMPHALIDAE de Koninck 1881
Genus DISCOHELIX Dunker 1848

Discohelix didimtuensis sp. nov.
Plo 22, figs. 14;.0;.¢;:¢

Diacnosis. Rather small (diameter of largest specimen 10:5 mm.), discoidal,
compressed, upper face flat, lower face umbilicate. Outer face low, slightly concave,
inclined inwards to a slight extent in an abapical direction, and separated from upper
face and from base by tuberculate carinae which project in an abaxial direction.
Some tubercles of both carinae are elongated transversely, so that on both the upper
face and the base they remain partly visible along the outer suture on the earlier
whorls, and in some specimens they are continued across the upper face of these
whorls by weak transverse riblets. The entire surface of the shell is ornamented with
delicate spiral threads.

HOLOTYPE AND PARATYPES. Nos. GG.10246 and GG.10247-—49 respectively, four
specimens in all.

LOCALITY AND HORIZON. Didimtu hill, two miles S. of Bur Mayo, N.E. Kenya ;
Upper Lias, Toarcian, Didimtu Beds.

REMARKS. In Discohelix dunkeri Moore (1867 : 85, pl. 5, figs. 28, 29; also
Dumortier 1874 : 141, pl. 35, figs. 18, 19), from the Upper Lias of southern England
and France, the ornament of the shell is closely comparable to that of the new species,
but the two carinae are less prominent and, between them, the outer face of the shell
is feebly convex ; transverse riblets originating at the tubercles are well marked on
both the upper face and the base. D. sinistra (d’Orbigny) (1853 : 310, pl. 322, figs.
1-7), from the Middle Lias of France, differs in much the same manner. D. albinati-
ensis Dumortier (1874 : 284, pl. 59, figs. 3-5 ; also Kuhn 1935 : 132, pl. 10, fig. 5),
from the Upper Lias of France and Germany, much resembles the new species, but
the lower of its two carinae projects abapically instead of outward, and the outer face
_ of the shell is convex rather than concave.

138 JURASSIC BIVALVIA AND GASTROPODA
Genus NUMMOCALCAR Cossmann 1896

Nummocalcar mitoleensis sp. nov.
Pl: 22. figs. 2¢,.0,¢

DiaGnosis. Of medium size (diameter 24 mm.), discoidal, with a barely pro-
truding spire, the apex of which is just visible when the shell is viewed from the side,
and with the periphery formed by a smooth, projecting carina at about mid-height.
Outer face, above the carina, flat and inclined inwards steeply as far as an angulation
which bears well separated, rounded nodes and forms the border of the flat upper face.
Base, consisting of all the surface below the carina, slightly concave in profile owing
to the presence of a broad swelling, bearing weak, transversely elongated tubercles,
on the outer side of a smooth spiral cord which forms the margin of the moderately
broad umbilicus. Where not eroded, the base bears weak spiral cords, but any spiral
ornament that may have been present above the peripheral carina has been oblitera-
ted by erosion. Aperture broader than high, but with its margin not preserved in-
tact ; growth-lines visible below the peripheral carina show that the outer lip was
strongly prosocline, and had a very broad sinus.

HoLotyPe. No. GG.10282, ex B.P. Coll. The only specimen.

LOCALITY AND HORIZON. Mpilepile stream bed, 1650 yards N.E. of Mitole road
junction, northern Mandawa area, Tanganyika ; Upper Kimmeridgian.

REMARKS. This species belongs to a group of Jurassic and Cretaceous forms
characterized by a carinate periphery and by tuberculate ornament on both the
upper face of the whorls and the base, the tubercles being elongated transversely in
some species to form ribs. The Albian species “ Solarium” subornatum d’Orbigny
(S. ornatum J. de. C Sowerby, non Lea) is a characteristic representative of this group
and is clearly congeneric with the form now described. Until a revision of all
Mesozoic discoidal and subdiscoidal shells can be carried out, Cossmann is followed
in referring the species of this group to Nummocalcar. In the type species of this
genus, however, strong transverse ribs on the upper face of the whorls end in promin-
ent spines on the peripheral carina. It is uncertain if this genus should be included
in the Euomphalidae, where it was placed by Cossmann, or if it should be assigned
to the Architectonicidae or possibly to a new family.

Superfamily PLEUROTOMARIACEA
Family PLEUROTOMARIIDAE Swainson 1840
Genus BATHROTOMARIA Cox 1956

Bathrotomaria aitkeni sp. nov.
Plz, fie OME l. 237 nessa

SPECIFIC NAME. After Dr. W. G. Aitken, lately Director of the Geological
Survey of Nyasaland, collector of the type specimens.
DiaGnosis. Large (original height of largest specimen 110 mm.), trochiform,

FROM TANGANYIKA AND KENYA 139

with diameter approximately equal to or slightly less than height and with narrow,
deep umbilicus. Whorls with slightly concave outer face, which is steeply and some-
what variably inclined, and a broad ramp, varying from feebly concave to feebly con-
vex, which forms an angle averaging about 45° with shell axis. Whorl shoulder
formed by rounded spiral cord bearing selenizone. Base feebly convex, its periphery
formed by second rounded cord which is almost of the same strength as the first and
is just exposed in places on the spire whorls. Ornament of ramp, whorl outer face
and base consisting of numerous spiral cords and threads of unequal strength.
(Collabral threads, if originally present, have been obliterated by erosion in the
specimens examined.)

HOLOTYPE AND PARATYPES. Nos. GG.10306 and GG.10307—08 respectively, three
specimens in all.

LOCALITIES AND HORIZON. At three points along the Mandawa—Namakongoro
stream, Mandawa—Mahokondo area, Tanganyika ; Middle-Upper Kimmeridgian.

REMARKS. Its large size distinguishes this species from any Jurassic Bathroto-
maria described previously. The English Upper Oxfordian and Kimmeridgian
species B. reticulata (J. Sowerby) (18214 : 128, pl. 272, fig. 2), which attains a dia-
meter of 90 mm., has not such a distinct carina at the periphery of its base and its
spiral ornament is rather more delicate. B. solodurina (Thurmann & Etallon) (1861 :
129, pl. 11, fig. 102), based on an internal mould 65 mm. in diameter from the Kim-
meridgian of the Swiss Jura, could possibly be a synonym of B. reticulata. B. neo-
solodurina (Dacqué) (1905 : 141, pl. 16, figs. 5, 6), from the Kimmeridgian of Somali-
land, is more depressed than the new species now described.

Superfamily PATELLACEA
Family uncertain
Genus PSEUDORHYTIDOPILUS Cox 1960 (ex Haber, nom. nud.)

Pseudorhytidopilus lonjiensis sp. nov.
Pl. 22, figs. 3a, b

Diacnosis. Outline broadly elliptical, rather flattened anteriorly and posteriorly ;
moderately large (length of holotype c. 33 mm., breadth c. 28 mm.), well elevated
(height of holotype c. 16 mm.), with apex situated at about anterior quarter of length
and directed anteriorly. Ornament consisting of conspicuous concentric growth-
undulations, about I mm. apart.

HoLotyPe. No. GG.10312. The only specimen.

LOCALITY AND HORIZON. Along Lonji-Runjo stream at a point 1} miles W. of
Mandawa, Tanganyika ; Callovian.

140 JURASSIC BIVALVIA AND GASTROPODA

REMARKS. The genus Rhytidopilus (type-species Patella humbertina Buvignier)
was founded by Cossmann (1895 : 143) for the reception of certain rather irregularly
conical internal moulds of shells of Mesozoic age with strong growth undulations and
a narrow, elevated sector, bordered by furrows, running from the apex to the anterior
margin. Pseudorhytidopilus includes patelliform shells which are similar to Rhytido-
pilus except that the raised anterior sector is absent. The species most closely com-
parable to the one now described is Pseudorhytidopilus arsinoe (d’Orbigny) (figured
by Thevenin 19134, pl. 36, figs. 1, 2), from the Callovian of France, but in that species
the apex is more elevated and placed in a less anterior position. Its anteriorly
pointing and much more forward-placed apex distinguishes the new species from the
three European Kimmeridgian species P. banneana (Rollier) (1918 : 11, for Patella
humbertina Thurmann & Etallon 1861, pl. 13, fig. 131, mon Buvignier), P. castellana
(Thurmann & Etallon) (1861, pl. 13, fig. 132), and P. lennieri Cox (1960 : 237, for
Helcion castellana Lennier 1872, pl. 8 B, figs. 8, 8a).

Family SYMMETROCAPULIDAE Wenz 1938
Genus SYMMETROCAPULUS Dacqué 1933

Symmetrocapulus ? sp.
Pl. 22, figs. 5a, b

1914. ?Patella (Fissuvella ?) sp. ; Dietrich : 116, pl. 11, fig. 4.

MATERIAL. One specimen (no. G.48031).

LOCALITY AND HORIZON. Tingutitinguti creek, Tendaguru, Tanganyika ; Upper
Kimmeridgian, “‘ Tvigonia smeet’”’ Bed.

REMARKS. The specimen now recorded is a small, radially ribbed, patelliform
shell nearly 9 mm. long. Like the specimens described by Dietrich, as cited above,
it has lost its apex, so that its generic affinities are uncertain. The apex was evident-
ly situated within the anterior third of the length of the shell, the dorsal profile rising
slightly above it posteriorly before curving down to the posterior margin. The
numerous radial riblets are unequal in breadth and rather irregularly distributed ;
their intervals are, on the average, of about the same width as the riblets. The whole
surface, where uneroded, can also be seen to bear fine concentric threads. Dietrich’s
figure appears to represent a specimen with broader and fewer ribs than the present
one, but the species may be the same. Haber (1932 : 249) suggested the reference
of Dietrich’s form to Symmetrocapulus (then a nomen nudum), but the part of his
catalogue in which it would have been listed systematically and possibly given a
specific name was never published.

:

FROM TANGANYIKA AND KENYA 141

Family ACMAEIDAE Carpenter 1857
Genus SCURRIOPSIS Gemmellaro 1879
Subgenus DIETRICHIELLA Wenz 1938

Scurriopsis (Dietrichiella) kindopensis (Dietrich)
Pl 22; figs: 4a, b

1914. Patella kindopensis Dietrich : 116, pl. 11, fig. 3.
1932. Scurria (Dietrichiella)® kindopensis (Dietrich) ; Haber : 220.
1938. Scurria (Dietrichiella) kindopensis (Dietrich) ; Wenz: 219, fig. 405.

MATERIAL. One specimen (no. G.48913).

LOCALITY AND HORIZON. Kindope valley, N.W. of Tendaguru, Tanganyika ;
Upper Kimmeridgian, “ Tvigonia smeei’’ Bed.

ReMARKS. This small patelliform gastropod, which is 11-3 mm. long and 7:2 mm.
broad, is a little larger than Dietrich’s holotype, but agrees with it in shape and orna-
ment. The latter consists of concentric rugae and of scarcely perceptible radial
grooves confined to the neighbourhood of the posterior margin. The apex is placed
at about one-sixth of the length of the shell from its anterior end, the longitudinal
profile from it to the posterior end forming an evenly convex curve.

Superfamily TROCHACEA
Family TROCHIDAE Rafinesque 1815
Subfamily PROCONULINAE Cox 1960

Genus AFRICOCONULUS nov.

Diacnosis. Shell slightly coeloconoid, well elevated, anomphalous ; last whorl
with two tuberculate or spinose carinae at periphery, the upper and stronger carina
forming prominent angulation, the lower one just visible at suture on spire whorls;
remainder of surface ornamented with simple or beaded spiral cords and raised
collabral threads ; base low, rather flattened ; columellar lip short, simple, describing
a broad curve abapically to merge with basal lip.

TYPE SPECIES. Proconulus spinatus Dubar (1948 : 126, pl. 10, figs. 7-9), Middle
Lias, Morocco.

Remarks. In this genus the ornament is rather like that of Eucyclus, but the
depressed base and the shape of the aperture indicate that there is no real affinity
with that subgenus. Dubar was undoubtedly correct in detecting some affinity
between his species, taken as its type, and Proconulus, but in typical species of that
genus the whorls lack prominent peripheral carinae and have only weak spiral
ornament. There is much resemblance between the new genus and Metaconulus
Cossmann, of the Lower Tertiary, but it is to be assumed that this was due to con-

8As published by Haber, this subgeneric name was a nomen nudum.

142 JURASSIC BIVALVIA AND GASTROPODA

vergence. In the Triassic genus Diplochilus Woehrmann, which also has two peri-
pheral carinae, the aspect of the ornament of the shell is quite different. In Dimor-
photectus Cossmann, also founded on a Triassic species, the very short columellar lip
has a prominent median fold.

Africoconulus kenyanus sp. nov.
Pl. 30, figs. ga, b, c

DiaGNnosis. Rather small (height of largest specimen 14 mm.), trochiform, with
well elevated, slightly coeloconoid spire ; diameter four-fifths of height ; aperture
occupying about two-fifths of total height. Spire whorls with a prominent carina
situated at lower third of their height and bearing prickly tubercles; above the carina
are two spiral rows of smaller tubercles coinciding with angulations of the surface,
the upper angulation bordering a narrow sutural ledge. Margin of base formed by
a second carina which continues the line of the suture ; this carina is slightly less
prominent than the one above it and bears smaller and more numerous tubercles
than those on the upper one. The base, which is very little extended, is flattened-
convex adaxially and is slightly excavated but not umbilicate mesially ; it bears a
few unevenly distributed spiral cords. In addition, the whole surface of the shell
bears raised collabral threads which are well separated in some specimens ; threads
slightly prosocline above main carina and more strongly so below it, while on the base
some become strengthened adaxially to form transverse riblets. Apertural margin
imperfect in all specimens.

HOLOTYPE AND PARATYPES. Nos. GG.10250 and GG.10251-57 respectively,
eight specimens in all.

LOCALITY AND HORIZON. Didimtu hill, 2 miles S. of Bur Mayo, N.E. Kenya ;
Upper Lias, Toarcian, Didimtu Beds.

REMARKS. This species is clearly congeneric with A fricoconulus spinatus (Dubar),
type species of the new genus, but is much smaller and its upper carina has not the
prominent spines which are present in that species.

Subfamily ANGARIINAE Thiele 1924
Genus CHRYSOSTOMA Swainson 1840
Chrysostoma staffi Dietrich
Pl. 24, figs. Ia—c
1914. Chrysostoma Staffi Dietrich : 122, pl. 11, fig. 6.

MATERIAL. One specimen (no. G.48567).

LOCALITY AND HORIZON. “‘ Ditch 2x’, Tendaguru, Tanganyika ; just above top
of lower “‘ Trigonia smeet ’’ Bed, i.e. Upper Kimmeridgian (cf. Parkinson 1930, fig. 3,
showing horizons near Tendaguru hill).

FROM TANGANYIKA AND KENYA 143

REMARKS. The specimen now recorded, which is 17 mm. in diameter and 14 mm.
high, agrees so well with Dietrich’s figure that there seems no doubt about its
specific identity. The spire of the shell is very obtuse, with slightly concave sides,
and the sutures are scarcely impressed. The last whorl is broadly rounded at the
periphery and the base is convex, quite uncoated with callus, and narrowly umbili-
cate. The outer lip is broken away, but the growth-lines are strongly prosocline.
The aperture, which occupied about five-sixths of the total height of the shell, was
evidently almost circular. The shell wall is thick and the surface quite smooth.

This specimen appeared at first sight to belong to the genus Ataphrus, from which
it differs, however, in its open umbilicus. Dietrich, when describing C. staffi, com-
mented on its striking similarity to Ataphrus laevigatus (J. Sowerby) (cf. Hudleston
1894 : 349, pl. 29, figs. 5, 6), of the Inferior Oolite. The holotype was said to come
from Neocomian beds at a locality near Mikadi, Tanganyika, but the specimen now
recorded appears to be from an Upper Jurassic horizon.

Family ATAPHRIDAE Cossmann 1918
Genus ATAPHRUS Gabb 1869

Ataphrus aft. acmon (d’ Orbigny)
Pl, 24, 08S. 20,0
1850a. Aff. Tvochus Acmon d’Orbigny : 265.
1853. Aff. Trochus Acmon d’Orbigny : 278, pl. 314, figs. 1-4.

1885. Aff. Ataphrus Acmon d’Orb. ; Cossmann : 281, pl. 7, figs. 9, ro.
1894. Aff. Ataphrus Acmon d’Orbigny ; Hudleston : 351, pl. 29, fig. 11.

MATERIAL. One specimen (no. G.26204).

LOCALITY AND HORIZON. Kidugallo, Central Railway, Tanganyika ; Bajocian,
Station Beds.

REMARKS. This specimen, which is about 9 mm. high, agrees very well with the
_ figures of the European Bajocian species A. acmon cited above. Its last whorl and
aperture, however, are imperfect, so that it seems advisable to qualify its specific
determination.

Genus TROCHOPSIDEA Wenz 1938

Trochopsidea africana sp. nov.
Pilg es. 54, 0) c,d

Diacnosis. Shell small (diameter of largest specimen c. 7 mm.), turbiniform,
diameter exceeding height ; spire obtusely cyrtoconoid, its height almost equal to
that of the aperture. Whorls smooth, of moderate and even convexity, the last one
broadly rounded at the periphery. Base evenly convex ; no umbilicus. Inner lip
with moderately wide, grooved outer face, which is limited by a carina and is devoid
of a tubercle.

144 JURASSIC BIVALVIA AND GASTROPODA

HOLOTYPE AND PARATYPES. Nos. GG.10258 and GG.10259-62 respectively, five
specimens in all.

LOCALITY AND HORIZON. Didimtu hill, 2 miles S. of Bur Mayo, N.E. Kenya ;
Upper Lias, Toarcian, Didimtu Beds.

REMARKS. The characters of the inner lip of this species agree with those of
Trochopsidea, the presence of the groove on the outer face of this lip distinguishing
the species from representatives of Ataphrus, which it resembles in its general
morphology. Turbo garnieri Dumortier (1874 : 139, pl. 35, figs. 15-17), from the
Upper Lias of southern France, which much resembles the present species except
that it is slightly more elevated, has not a grooved inner lip and appears to belong to
Ataphrus (Endianaulax). A specimen from the Upper Lias of Germany identified by
Kuhn (1935 : 136, pl. 8, fig. 21) as Ataphrus cf. lucidus (Thorent) (a species included
by Cossmann in the subgenus Endianaulax) is more depressed than the present form.

Superfamily NERITACEA
Family NERITIDAE Rafinesque 1815
Genus NERITOMA Morris 1849
Subgenus NERIDOMUS Morris & Lycett 1851

Neritoma (Neridomus) aff. gea (d’Orbigny)
Pl. 24, figs. 7a, b

1852. Aff. Nevita Gea d’Orbigny : 232, pl. 302, figs. 5-7.
1885. Aff. Nevita Gea d’Orb. ; Cossmann : 155, pl. 3, figs. I, 2.
1908. Aff. Nevita gea d’Orbigny ; H. Fischer: 268, pl. 11, figs. 5-12.

MATERIAL. Three specimens (nos. G.61310—12).

LOCALITY AND HORIZON. S. of Tarawanda, 26 miles W.S.W. of Bagamoyo,
Tanganyika ; Callovian.

REMARKS. The specimens now recorded, the best of which is just under Io mm.
in height and diameter, are characterized by their low spire, obtusely rounded apex,
and flush sutures. The apex and axis are rather strongly eccentric. The speci-
mens belong to a group of species which is well represented in the Bathonian of
Europe and has been discussed by H. Fischer (1908). They seem to be very closely
comparable to Nevitoma (Neridomus) gea, but they are a little larger than the
specimens figured by the authors cited above, and their axis is more eccentric.
They are also rather similar in shape to N. (N.) lowisiae Fischer (1953 : 15, pl. I,
figs. 21-27), also from the French Bathonian, but that species attains a much
larger size (20 mm.) and has a more pointed apex. Cossmann (1926 : 305, pl. 5,
figs. Ia—c) has recorded a specimen of the same group from the Callovian of Sinai
under the name Neridomus punctatus (Piette), but it is also considerably larger
than the specimens now recorded. The species Neritodomus sukidugallensis Reck
(1921 : 435, text-fig. 3) was founded on a small broken shell from the Bajocian

FROM TANGANYIKA AND KENYA 145

of a locality along the Central Railway, Tanganyika, and appears to have a more
prominent apex than the form now recorded. The shell from the Saurian Beds
of Tendaguru recorded by Dietrich (1914 : 126, pl. 11, figs. 10a, b) as Nenta cf.
transversa Vv. Seebach var. minor de Loriol differs from the specimens now recorded
in much the same manner as does N. lowiszae.

Genus LISSOCHILUS Zittel 1882

Lissochilus stremmei Dietrich
Pl. 24, figs. 4a, b

1914. Nerita (Lissochilus) Stremmei Dietrich : 126, pl. 11, figs. 11a-e.

MATERIAL. Three specimens (nos. G.48903, G.48912, GG.103I5).

LOCALITIES AND HORIZONS. Kipande, W. of Tendaguru, Tanganyika ; Upper
Kimmeridgian, Nerinea Beds. Kindope valley, N.W. of Tendaguru ; Upper
Kimmeridgian, “‘ Tvigonia smeet’”’ Beds. 14 miles N.W. of Mandawa, Tanganyika ;
Upper Kimmeridgian.

REMARKS. In this species a strong rounded carina forms the periphery of the shell
and a strong, rounded-off angulation marks the boundary of a subhorizontal sutural
shelf. Below the periphery are several spiral cords, one of which may stand out as a
keel. Rather irregularly distributed collabral ridges are most conspicuous on the
later formed part of the last whorl and give rise to tubercles on some of the spirals.
The two largest specimens now recorded, which are rather eroded, are about 23 mm.
in diameter.

Superfamily PALAEOTROCHACEA
Family PARATURBINIDAE Cossmann 1916
Genus CHARTRONELLA Cossmann 1902

Chartronella mitoleensis sp. nov.
Pl. 24, figs. 3a, b

DiacGnosis. Shell of medium size, trochiform, with height (19 mm. in the holo-
type) very slightly exceeding diameter. Whorls bicarinate, the upper carina
forming the edge of a subhorizontal, slightly concave sutural ledge, the lower, which
projects abaxially slightly more than the upper one, just exposed above the suture
on the later whorls and forming the periphery of the base of the shell. Outer face
of whorls, between the carinae, concave. Base convex, umbilicus absent. Narrow
spiral cords, with transverse threads crossing their intervals, are present near the
carinae, but spiral ornament is absent from the remainder of the shell (it could
conceivably, however, have been removed by erosion in the holotype). Aperture
almost circular (the outer lip is broken in the holotype) ; a spiral swelling originating
at the lower margin of the aperture forms the lower border of the convex part of the
base.

146 JURASSIC BIVALVIA AND GASTROPODA

Ho.otyPe. No. GG.10313 ; there is no other material except an associated
internal mould, which scarcely ranks as a paratype.

LOCALITY AND HORIZON. Mpilipili stream at a point about 1 mile N.E. of Mitole,
Tanganyika ; Upper Kimmeridgian.

ReMARKS. This form resembles the type-species of Chartronella, C. digoniata
(Cossmann) (1902 : 199, pl. 4, figs. 24-26), from the Hettangian of France, in its
bicarinate but otherwise almost smooth whorls, in its convex base, and in the absence
of an umbilicus, but it differs in the fact that the upper of its two carinae marks the
edge of a subhorizontal ledge instead of a steeply sloping sutural ramp, so that its
whorls are much lower than in Cossmann’s species.

Family CIRRIDAE Cossmann 1916
Genus CIRRUS J. Sowerby 1815

Cirrus mazerasensis sp. nov.
Pl. 24, figs. 8a, b

Diacnosis. Of medium size (original height of holotype, allowing for missing
last whorl, c. 25 mm. ; height of spire as preserved, c. 15 mm.), sinistral. Spire
coeloconoid with a very acute apex, and consisting of whorls which are at first almost
flat but become increasingly convex during growth. Ornament consisting of vari-
ably but mostly strongly prosocline transverse riblets and of strong concentric
threads which override them and occupy their intervals ; the ribs, which appear
close to the upper suture but die out before reaching the lower one, are separated by
intervals which are almost equal to them in width on the earlier whorls but become
almost twice as wide on the last preserved whorl ; the spirals number 6 on the later
whorls and are separated by intervals about twice as wide. Last whorl and aperture
unknown.

HototyrPe. No. GG.6524, an external mould of the spire of the shell from which
squeezes have been prepared.

LOCALITY AND HORIZON. Ribe, g miles N.E. of Mazeras, Kenya ; Bajocian (?),
Mazeras Sandstones.

REMARKS. The strongly coeloconoid spire suggests that the last whorl (no longer
preserved) was umbilicate, so that the species is a Civrus rather than a Hamusina.
No species with identical ornament can be traced in the literature.

Genus HAMUSINA Gemmellaro 1878
Hamusina thompsoni sp. nov.
Pl. 24, figs. ga, b

SPECIFIC NAME. After Mr. A. O. Thompson, of the Geological Survey of Kenya.
Diacnosis. Shell small for the genus (height 11 mm.), acute, sinistral, with
aperture occupying about one-third of total height ; spire angle c. 30°. Periphery

FROM TANGANYIKA AND KENYA 147

of whorls, situated at about the lower third of their height, formed by an obtuse
angulation bearing large rounded tubercles, above which the whorl outline is feebly
concave. Spire whorls ornamented, in addition, with a row of small tubercles
bordering the upper suture and with very weak spiral threads which are present on
their entire surface except where removed by erosion. Margin of base formed by a
narrow, smooth cord continuing the line of the suture ; base ornamented with spiral
riblets. Aperture circular (its margin is imperfect).

HoLotyPe. No. GG.10263. The only specimen.

LOCALITY AND HORIZON. Didimtu hill, 2 miles S. of Bur Mayo, N.E. Kenya ;
Upper Lias, Toarcian, Didimtu Beds.

REMARKS. This small shell is unquestionably congeneric with Turbo bertheloh
d’Orbigny, the type species of Hamusina, but it differs from that species in obvious
details of ornament. No species very closely comparable to it is described in the
literature.

Superfamily SUBULITACEA
Family PPEUDOMELANIIDAE Fischer 1885
Genus PSEUDOMELANIA Pictet & Campiche 1862

Pseudomelania aspasia (d’Orbigny)
Pl. 24, fig. Io

1850a. Chemnitzia Aspasia d’Orbigny : 208.

1851. Chemnitzia Aspasia d’Orb. ; d’Orbigny : 49, pl. 242, fig. 4.

1851. Chemnitzia niortensis d’Orbigny : 48, pl. 242, figs. I, 2.

1885. Pseudomelania niortensis (d’Orb.) ; Cossmann : 172, pl. 9, figs. 6, 7.

MATERIAL. One shell (no. GG.10317). Two incomplete internal moulds may also
belong to the species.

LOCALITIES AND HORIZONS. Shell-bearing specimen from Nchia stream, 2 miles
W.N.W. of Mandera, Tanganyika ; internal moulds from Lonji stream, E.N.E. of
Nandenga, Tanganyika ; Callovian.

REMARKS. The shell-bearing specimen agrees so closely with the figures of P.
aspasia published by d’Orbigny and by Cossmann that I see no reason to qualify its
specific determination. The species occurs typically in the Bathonian of France.
In P. caecitha (d’Orbigny) (1851 : 64, pl. 248, fig. 2 ; de Loriol 1874 : 331, pl. 8,
figs. 1a, b), from the Lower Kimmeridgian of France, and P. laufonensis Thurmann
& Etallon (1861 : 88, pl. 6, fig. 27), a Swiss species of about the same age, the spire
angle is about the same but the whorls are quite flat.

On the internal moulds now recorded there is a tendency for a spiral groove to be
developed low on the side of the whorl, just above the lower suture. As it is dis-
continuous it does not appear to represent a spiral fold on the interior of the whorls
and it may have arisen by deformation of the internal mould after the shell had
disappeared in solution.

148 JURASSIC BIVALVIA AND GASTROPODA

Pseudomelania dusseensis sp. nov.
Plh24 Phiess ria) bse

DiaGnosis. Shell small (height about 11 mm.), regularly conical, moderately
acute (spire angle about 16°), with the spire formed of rather low, very feebly convex
(virtually flat) whorls, separated by flush sutures ; height of spire whorls equal to
about one-half of their diameter. Last whorl abruptly rounded, almost angular at
periphery ; base low, feebly convex, without umbilicus. Aperture broader than
high ; outer lip flat or very feebly convex ; columellar lip short. Surface smooth ;
growth-lines, where faintly visible, arched, with a shallow forward-facing concavity.

HOLOTYPE AND PARATYPES. Nos. G.76399 and G.76400-02 respectively, four
specimens in all.

LOCALITY AND HORIZON. Low hills at Dussé, 14 miles S.E. of Rahmu, N.E.
Kenya ; Upper Oxfordian, Seir Limestones.

REMARKS. This species closely resembles Pseudomelania communis (Morris &
Lycett) (1851 : 48, pl. 9, figs. 21, 21a), from the English Bathonian, but is distin-
guished by its flatter whorls. P. Jaubei Cossmann (1885 : 176, pl. 11, figs. 32, 33 ;
pl. 15, fig. 47), from the Bathonian of France, is a larger shell (25 mm. high), with
slightly higher whorls. In the French Callovian species P. calloviensis (Hébert &
Deslongchamps) (Couffon 1919 : 126, pl. 8, figs. Ig-I9e ; Cossmann 1924 : 4, pl. I,
figs. 21-23) the whorls are relatively higher. P. calloviensis has axial riblets on its
earliest formed whorls and therefore belongs to the subgenus Hudlestoniella Coss-
mann. As the corresponding whorls are missing on the specimens now described it
is not possible to say if the species should be included in that subgenus rather than in
Pseudomelamia s. str. Of European Oxfordian species, P. ebersteini (Thurmann) (de
Loriol 1899 : 133, pl. 9, fig. 20), from the Swiss Jura, is a broader shell than the form
now described and has more strongly convex whorls.

Pseudomelania vittata (Phillips)
Pl, 24; fig. j12

1829. Melania vittata Phillips : 145, pl. 7, fig. 15.

1863. Chemnitzia vittata (Phil.) ; Lycett: 14, pl. 31, fig. ro.

1882. Chemnitzia vittata (Phil.) ; Hudleston : 244, pl. 6, figs. 5a, b, 6.
1905. Pseudomelania vittata (Phil.) ; Blake: 77, pl. 8, figs. 1, 2.
1950. Pseudomelania vittata (Phillips) ; Cox & Arkell: 62.

MATERIAL. One specimen (no. GG.10316).

LOCALITY AND HORIZON. I mile N. of Manyuli, Tanganyika ; Upper Kim-
meridgian.

REMARKS. Pseudomelania vittata is a large form characterized by the presence
on the last whorl of two strong but obtuse keels, between which the face of the shell
is slightly concave. On the spire whorls the upper keel lies at about the posterior
third of the height, while the lower keel may or may not be visible near the lower
suture, according to the degree of whorl overlap. I am unable to distinguish the

FROM TANGANYIKA AND KENYA 149

East African specimen from those from England, where, however, the species seems
to be confined to the Cornbrash (Upper Bathonian-Callovian). The original length
of this specimen was about 120 mm., but it now lacks the apical whorls.

In the well-known species P. heddingtonensis (J. Sowerby), of the Upper Oxfordian
and Lower Kimmeridgian of Europe, the size and proportions of the shell are much
the same as in the specimen now recorded, and in some specimens there is a slight
spiral swelling of the whorl face in the same position as the upper carina of P. vittata.
The outer face of the whorl is, however, convex and there is no carina at the per-
iphery of the base. Hudleston (1882 : 245) commented on the doubtful value of
the specific distinctions drawn between a number of Jurassic “‘ Chemnitzias ’’,
but thought that the slight differences noted might depend upon the geological
horizon. It is evident from the occurrence now recorded that the differences
between P. vittata and P. heddingtonensis have no stratigraphical significance.

Of other Upper Jurassic species of the group now described, P. sulcata (Zieten)
(Brdésamlen 1909 : 283, pl. 21, fig. 15), from the Kimmeridgian of Nattheim, southern
Germany, and a series of forms from France (P. athleta, P. pollux, P. columna, P.
domotsi, etc.) illustrated by d’Orbigny (1851, pls. 245-248), all, like P. heddington-
ensis, differ from P. vittata in lacking the lower of the two carinae on the last whorl.

Subgenus OONIA Gemmellaro 1878

Pseudomelania (Oonia) kidugalloensis sp. nov.
Pl. 26, figs. 4@, 6, ¢

Diacnosis. Shell of medium size for the genus (height of holotype 10-4 mm.),
phasianelliform, height of aperture about three-sevenths of that of shell ; spire
angle about 40°. Protoconch unknown complete. Spire whorls strongly convex,
about twice as broad as high, abutting simply at the sutures ; last whorl evenly
convex at periphery. Base also evenly convex in outline, not much extended,
without umbilicus. Aperture obliquely oval, its height nearly twice its breadth.
Columellar lip short, apparently joining basal margin of aperture in an even curve.
Outer lip almost orthocline ; details of parietal region not well seen. Growth-lines
obscure.

HoLotyPe. No. GG.10280. The only specimen.
LOCALITY AND HORIZON. 24 miles N.N.W. of Kidugallo, Tanganyika ; Bajocian.

RemaRKS. This species seems closely comparable to the English Bajocian species
“ Phasianella’’ latiuscula Morris & Lycett, as figured by Hudleston (1891 : 251, pl.
19, figs. 10a, b), but its spire occupies a relatively greater proportion of the height of
the shell than in that species and it is much smaller. The English species is included
in Pseudomelania (Oonia) by Cox & Arkell (1950 : 97).

150 JURASSIC BIVALVIA AND GASTROPODA

Pseudomelania (Oonia) conica (Morris & Lycett)
Pl. 25, figs. 2a, b, c

1851. Phasianella conica Morris & Lycett : 74, pl. 11, figs. 30, 30a.

1851. Phasianella acutiuscula Morris & Lycett: 75, pl. 9, fig. 2; pl. 11, figs. 28, 28a (non
Lycett 1850).

1885. Phasianella acutiuscula Morris & Lycett : Cossmann : 253, pl. 9, fig. 18 ; pl. 17, figs.
22,723:

1900. Phasianella ? acutiuscula Morris & Lycett ; Cossmann : 571, pl. 17, fig. 19.

1907). Phasianella ? acutiuscula Morris & Lycett ; Cossmann : 253, pl. 7, fig. 5.

MATERIAL. One specimen (no. GG.10463).

LOCALITY AND HORIZON. 2 miles W. of Tengeni (village on Pangani river), in
Mbuzi Mkubwa stream, Tanganyika ; Bathonian (?).

REMARKS. The specimen, which is 21-5 mm. high, agrees well with some speci-
mens from the Great Oolite of England, although it is slightly more slender than those
figured by Morris and Lycett. The sutures are flush and the spire is slightly
cyrtoconoid. Another Bathonian species, P. (O.) variata (Lycett 1863 : 104, pl. 45,
figs. 28, 28a, b), especially as figured by Cossmann (1885 : 255, pl. 4, fig. 52: pl. 11,
fig. 17), is also of much the same proportions as the shell now recorded, but its sutures
are more impressed and its base is less extended.

Pseudomelania (Oonia) dietrichi sp. nov.
Pl. 24, figs. 6a, b

1914. Pseudomelania (Oonta) aff. Sancti Antoni (Struckmann) ; Dietrich : 129, pl. 11, figs.
17a-C.

DiaGnosis. Shell of medium size (height of holotype 34 mm.), of moderate acute-
ness (spire angle about 30°) ; aperture occupying about three-sevenths of total
height. Whorls strongly and evenly convex, their mean height equal to about one-
half of their diameter. Ornament consisting of faint spiral striae together with
growth rugae which are strongly pronounced on the last whorl and are slightly arched,
with a backward-facing convexity.

HOLOTYPE AND PARATYPES. Nos. G.48028 and G.48021-27 respectively, eight
specimens in all.

LOCALITY AND HORIZON. Tingutitinguti creek, Tendaguru, Tanganyika ; Upper
Kimmeridgian, ‘‘ Tvigonia smeet’”’ Bed.

REMARKS. A search through the literature has confirmed Dietrich’s conclusion
that the most closely comparable species previously described is Chemnitzia Sancti
Antoni Struckmann (1878 : 110, pl. 7, figs. 2a, b,3), from the Kimmeridgian of Ahlem,
near Hanover. In the species in question, however, the shell is slightly more acute
than in the Tendaguru shell and a fine reticulate ornament is present, in which the
spiral threads are slightly more prominent than the collabral ones, whereas in the
East African form the spiral lines are scarcely visible to the unaided eye and much

FROM TANGANYIKA AND KENYA I51

weaker than the collabral rugae. Another comparable European species is P.
collisa de Loriol (1874 : 334, pl. 7, figs. 30, 31), from the Lower Kimmeridgian of
France, but its whorls are slightly more convex than those of the form now described.

Pseudomelania (Oonia) aitkeni sp. nov.
Pl. 25, figs. 1a, b, c

SPECIFIC NAME. After Dr. W. G. Aitken, lately Director of the Geological
Survey of Nyasaland, and collector of the holotype.

DiacGnosis. Shell of medium size (height of holotype c. 22 mm.), ovate-conical,
with diameter equal to about one-half of height. Spire slightly coeloconoid, with
very acute apex. Spire whorls low, their mean height rather less than one-third of
their diameter, feebly convex, the later ones with a narrow, ill-defined sutural ledge.
Last whorl broadly and evenly convex at periphery, outline of base scarcely exca-
vated ; no umbilicus. Aperture oval, originally occupying about one-half of total
height of shell (its margin, however, is broken away in the holotype). Surface
smooth.

HoLotyPe. No. GG.10318. The only specimen.

LOCALITY AND HORIZON. Along Mandawa—Namakongoro stream, about I mile
W. of Mandawa, Tanganyika ; Middle-Upper Kimmeridgian.

REMARKS. As the apertural margin is broken away in the holotype it is not
possible to observe if (as in the Pseudomelaniidae) it was uninterrupted anteriorly
or if (as in some Coelostylinidae) a small notch or sinus was present at the foot of the
columella. The species is here referred to the pseudomelaniid subgenus Oomza, from
the typical species of which it differs in its aciculate apex. It is of about the same
size and proportions as Pseudomelania (Oonia) recki Dietrich (1914 : 130, pl. I1,
figs. 16a, 6), from Tendaguru, but is readily distinguished by its coeloconoid spire
and more numerous and flatter whorls. In P. (O.) cornelia (d’Orbigny) (1851 : 60,
pl. 245, figs. 2, 3), from the “ Corallian ” of the Ardennes, and in P. (O.) quirandi de
Loriol (1887 : 145, pl. 15, figs. 5, 6), from the Lower Kimmeridgian of Valfin (Jura),
the spire is slightly cyrtoconoid and the last whorl is less inflated. P. (O.) daphne
de Loriol (1890 : 87, pl. 11, fig. 6), from the Upper Oxfordian of the Bernese Jura,
is a smaller shell.

Subgenus RHABDOCONCHA Gemmellaro 1878

Pseudomelania (Rhabdoconcha) wilderriensis sp. nov.
Pl. 25, fig. 10

1960. Pseudomelania valfinensis de Loriol ; Joubert, pl. 11, fig. 13b (non de Loriol).

Dracnosis. Shell large (original height of holotype c. 120 mm.), acute (spire
angle 12°), with feebly and evenly convex whorls the height of which is about three-
quarters of the diameter ; last whorl broadly convex at periphery. Surface orna-

152 JURASSIC BIVALVIA AND GASTROPODA

mented with numerous fine spiral striae ; growth-lines forming a simple, shallow
arch the chord of which is moderately prosocline. (The aperture is not preserved
intact.)

Hototyre. No. G.76414. The only specimen.

LOCALITY AND HORIZON. Wilderri hill, 11 miles S.S.W. of Rahmu, N.E. Kenya ;
Upper Oxfordian, Seir Limestones.

REMARKS. When first illustrated, the shell now described was identified as
Pseudomelania valfinensis de Loriol (1887 : 141, pl. 14, fig. 7). Its spiral ornament,
which is clearly seen on parts of the holotype (although the surface is rather eroded),
resembles that of this European Lower Kimmeridgian species, but its spire is more
acute.

Genus BOURGUETIA Terquem & Jourdy 1870

Bourguetia saemanni (Oppel)
Pl 25, figs. &, 9

1814a. Melania striata J. Sowerby : tot, pl. 47 (non Perry, 1811).

1853. Phasianella striata (Sow.) ; d’Orbigny : 322, pl. 324, fig. 15, pl. 325, fig. 1.
1856. Phasianella saemanni Oppel : 507.

1881. Bourguetia striata (Sow.) ; de Loriol : 31, pl. 8, fig. 5.

1905. Bourguetia striata (Sow.) ; Dacqué: 143.

1909. Bourgouetia (sic) striata (Sowerby) ; Brosamlen : 284.

1938. Bourguetia saemanni (Oppel) ; Cox : 60.

1960. Bourguetia saemanni (Oppel) ; Joubert, pl. 12, figs. 2a, b.

MATERIAL. Several specimens.

LOCALITIES AND HORIZONS. Nchia stream, 2 miles W.N.W. of Mandawa, Tangan-
yika ; Callovian. Scarp face, eastern margin of Makoko plain, Bagamoyo hinter-
land, Tanganyika ; Upper Oxfordian. Low hills at Dussé, 13 miles S.E. of Rahmu,
N.E. Kenya ; Upper Oxfordian, Seir Limestones. Wilderri hill, 11 miles S.S.W.
of Rahmu ; same formation as the last. Hereri river crossing, 3 miles S. of Melka
Kunha, N.E. Kenya ; Kimmeridgian, Hereri Shales.

REMARKS. The occurrence in East Africa of this well-known large European
Jurassic shell, already recorded from the Kimmeridgian of Somaliland by Dacqué, is

of great interest. In Europe the range of this species is from the Bajocian to the
Lower Kimmeridgian.

Family COELOSTYLINIDAE
Genus COELOSTYLINA Kittl 1894

Coelostylina stockleyi sp. nov.
Pl. 26, figs. 34, 6, c

SPECIFIC NAME. After Mr. G. M. Stockley, formerly Director of the Geological
Survey of Tanganyika.

FROM TANGANYIKA AND KENYA 153

Diacnosis. Shell of medium size for the genus (original height of holotype c. 12
mm.), phasianelliform, height of aperture about two-fifths of that of shell ; spire
angle about 35°. Protoconch unknown (broken off in holotype). Spire whorls
rather high, moderately convex, abutting simply at the sutures ; last whorl broadly
convex at periphery. Base evenly convex in outline, not much extended ; no
clearly open umbilicus is seen, but a small cleft in the base of the holotype may be
the opening of a very narrow one. Aperture ovate, angular posteriorly, not oblique.
Columellar lip straight and vertical although not much extended, slightly undercut
by a well-marked sinus which separates it from the basal margin of the aperture.
Outer lip orthocline ; details of parietal region not well seen in available specimen.
Growth-lines obscure.

HoLotyPe. No. GG.10281. The only specimen.
LOCALITY AND HORIZON. 23 miles N.N.W. of Kidugallo, Tanganyika ; Bajocian.

REMARKS. The apertural characters of this species and of the one described next
agree with those of members of the family Coelostylinidae rather than with those of
the pseudomelaniid subgenus Oonia, which they greatly resemble in the general
morphology of the shell. The only Bajocian and at the same time the geologically
youngest representative of the family hitherto recognized, is Coelostylina brasili
Cossmann (19130 : 217, pl. 8, figs. 58, 59), from France. This form is more than
twice the height of the species now described and has a less distinct sinus at the foot
of its columella. Cossmann pointed out that certain species from the Bajocian of
England described by Hudleston (1891 : 251-255, pl. 19, figs. 11-15) under the
generic name Phasianella might well belong to Coelostylina. Specimens identified
by him (1891, pl. 19, figs. 11a, 6, 146) as Phasianella elegans Morris & Lycett (a
Bathonian Oonia) are very similar to the African species now described.

Coelostylina mandawaensis sp. nov.
Pl. 25, figs. 4a, b, 5a, b, 6a, b, 7a, b

Diacnosis. Shell of medium size for the genus (height of largest specimen 13
mm.), ovate-conical, aperture occupying rather less than one-half of total height.
Protoconch minute, dome-like. Spire slightly cyrtoconoid, acute, consisting of
feebly to moderately convex whorls abutting simply at the sutures ; last whorl
broadly rounded at periphery. Base extended, evenly convex in outline ; no clearly
open umbilicus is seen, but a small median cleft in the base may be the opening of a
very narrow umbilicus. Aperture much higher than broad. Columellar lip ex-
tended, straight and vertical or leaning slightly to the left adapically and joining the
basal margin in a very abrupt curve, the junction forming a slight beak-like pro-
tuberance. Margin of columellar lip narrowly reflected, partly covering umbilical
cleft and continued across parietal region by margin of a thin inductura which passes
beneath the outer lip. Growth-lines prominent on last whorl, prosocline near the
suture, orthocline below.

HOLOTYPE AND PARATYPES. Holotype, no. GG.10283. Numerous paratypes,
including nos. GG.10284-86.

154 JURASSIC BIVALVIA AND GASTROPODA

LOCALITIES AND HORIZON. Near site of Mandawa well no. 1, Tanganyika (type-
locality). Mandawa well no. 6, Tanganyika, at depths 58-60 feet, 60-62 feet, 62-64
feet, 64-66 feet, 66-68 feet. Lihimaliao creek, at a point near Mbaru creek, Man-
dawa area, Tanganyika (a specimen preserved in matrix adherent to a crushed speci-
men of Protocardia bipi). All Bajocian (?),

REMARKS. There has been some difference of opinion as to the distinction be-
tween Coelostylina and Omphaloptycha, a genus founded by von Ammon two years
earlier. According to the criteria accepted by Cossmann (1909 : 47), the species
now described might appear better referable to Omphaloptycha, its ovate-conical form
and the feeble convexity of its whorls distinguishing it from the type-species of
Coelostylina. Nevertheless, in a later work Cossmann (1913) : 211-218, pl. 15)
refers a number of species, very much like the African shell, to Coelostylina. I think
it undesirable to separate this form generically from C. kidugalloensis sp. nov., des-
cribed above, and I therefore also include it in Coelostylina. It differs from C.
kidugalloensts in its less convex whorls and its more extended and relatively narrower
aperture.

Superfamily LOXONEMATACEA
Family ZYGOPLEURIDAE Wenz 1938
Genus ZYGOPLEURA Koken 1892

Zygopleura mandawaensis sp. nov.
Pl. 25, figs. 3a, b, 11

DiaGnosis. Shell rather small (height of largest specimen about 12 mm. when
complete), acute ; spire angle abut 15°. Protoconch finely pointed. Whorls with
an imbricate appearance, due to presence of an obtuse angulation at about the lower
quarter of their height, above which their outline is flattened ; the angulation forms
the periphery of the last whorl. Ornament consisting of strong, rounded collabral
costae separated by intervals of about the same width ; in some specimens the costae
are opisthocyrt for the whole of their exposed length, while in others they are para-
sigmoid, with the part above the angulation opisthocyrt and the part below proso-
cline. On the penultimate or the last whorl the costae fade away, so that the surface
bears only collabral threads or rugae. Base smooth, feebly convex to almost flat in
outline. Outer lip with broad sinus corresponding to opisthocyrt part of costae.

HOLOTYPE AND PARATYPES. Holotype, no. GG.10287 (ex B.P. Coll.), a specimen
associated with the holotype of Ceratomya tanganyicensis, sp.nov. There are several
paratypes, including nos. GG.10288—89, none complete.

LOCALITIES AND HORIZON. Lihimaliao creek traverse, Mandawa area, Tangan-
yika (type-locality). Mandawa well no. 6, Tanganyika, at the following depths :
58-60 feet, 60-62 feet, 62-64 feet, 64-66 feet. Near site of Mandawa well no. I.
All Bajocian (?).

RemMarKS. The Middle Jurassic species of Zygopleura so far described are relatively
large forms, 50-100 mm. in height, and it is necessary to turn to the Lias to find any

FROM TANGANYIKA AND KENYA 155

species with which the present one could be brought into comparison. Z. subrugosa
McDonald & Trueman (1921 : 330, text-fig. 18), from the Upper Lias of Grantham,
Lincolnshire, resembles the East African species in its angular whorl profile and does
not greatly exceed it in height, but it is a less acute shell, the periphery of its whorls is
much more protruding, and the number of costae on each whorl is greater.

Superfamily LITTORINACEA
Family PURPURINIDAE Zittel 1895
Genus PURPUROIDEA Lycett 1848

Purpuroidea supraliasica sp. nov.
Pl. 28, figs. 4a, b

DiaGnosis. Shell rather small for the genus (height of largest specimen c. 30
mm.), conical-ovate, diameter two-thirds of height, spire elevated, acute, occupying
up to one-half of total height. Whorls with almost flat sides, slightly convergent
adapically, separated from narrow sutural ramp by shoulder bearing large rounded
tubercles. Base extended, slightly convex in outline, and limited by an obtuse,
rounded-off angulation that continues the line of the suture. Parietal lip straight,
oblique, with a narrow, distinctly margined layer of callus, and joining the apparently
very short columellar lip (not preserved complete in the available specimens) in an
obtuse angle. Outer lip not preserved in the available specimens, in which any finer
ornament that may have been present has been obliterated by erosion.

HOLOTYPE AND PARATYPES. Nos. GG.10264 and GG.10265-69 respectively, six
specimens in all.

LOCALITY AND HORIZON. Didimtu hill, 2 miles S. of Bur Mayo, N.E. Kenya ;
Upper Lias, Toarcian, Didimtu Beds.

REMARKS. This shell is comparable in shape to the much larger species Purpurot-
dea berberica Dubar (1948 : 94, pl. 7, figs. 6-8), from the Middle Lias of Morocco,
and has a similar tuberculate shoulder to its whorls. Its base, however, is more
extended than in that species.

Purpuroidea aff. gigas (Thurmann & Etallon)
PIN'26, ties’2"; Pl? 27, fig: 15
1861. Aff. Purpura gigas Thurmann & Etallon : 138, pl. 13, fig. 121.
1874. ?Aff. Purpurina subnodosa (Roemer) ; Brauns : 169 (non Natica? subnodosa Roemer).
1881. Aff. Purpuroidea gigas (Etallon) ; Schlosser : 68, pl. 10, figs. 4, 4a.
1909. ?Aff. Purpuroidea subnodosa (Roemer) ; Brosamlen : 251 (non Roemer sp.).
MATERIAL. One specimen (no. GG.10328).

LOCALITY AND HORIZON. #? mile N.W. of Mbinga, Tanganyika ; Upper Kim-
meridgian.

156 JURASSIC BIVALVIA AND GASTROPODA

REMARKS. The specimen now recorded is a large internal mould, 153 mm. high.
Its apical whorls are broken away, but the original height of its spire may be esti-
mated as 60 mm. The maximum diameter of the last whorl is about 130 mm.
The last whorl has a rounded-off shoulder bearing large blunt tubercles, about nine
in number, and above the shoulder is a sutural ramp of steadily increasing breadth
which eventually forms an angle of about 45° with the axis of the shell. The
tubercles and ramp are not seen on the mould of the earliest preserved whorls. The
outer face of the last whorl is of feeble convexity and more or less vertical, its outline
merging in a broad curve into that of the base, which is strongly excavated at the
beginning of the short neck of the specimen. It is improbable that an umbilicus
was present in the original shell.

Schlosser (1881) placed Natica? subnodosa Roemer (1836 : 157, pl. 10, fig. 10) in
the synonymy of Purpuroidea gigas but did not adopt the earlier of the two specific
names. Brdsamlen (1909) accepted this synonymy and adopted Roemer’s name.
Examination of Roemer’s figure of N.? subnodosa, however, raises considerable doubt
as to whether this represents a Purpuroidea at all. It illustrates a specimen with a
wide, flat sutural ledge, separated by a sharp, obscurely nodose angulation from the
vertical outer face of the whorl. No difference in the thickness of the wall of the
shell would produce a difference in the form of the internal mould comparable to
that between Roemer’s figure and the illustrations of P. gigas given by Thurmann &
Etallon and by Schlosser. Moreover, I have recently had occasion to study a speci-
men from the Jurassic of Tunisia resembling Roemer’s figure of Natica? subnodosa.
The specimen in question recalls the Hettangian species Ampullaria carinata Ter-
quem, which Cossmann (1913) : 174, pl. 9, figs. 14-17) has included in the genus
Tretospiva Koken. It may, therefore, be suggested that Roemer’s figure represents
a specimen belonging to that genus. Unfortunately, no specimens from northern
Germany of the species which Brauns records as Purpurina subnodosa (Roemer) and
states is characteristic of the Kimmeridgian are available to me, but it is to be sus-
pected that its identification with Roemer’s species is incorrect. Brauns states that
specimens of the species reach a height of 180 mm. and a diameter of 50 mm. The
specimen from East Africa now recorded agrees quite well with the illustrations of
P. gigas given by the authors cited, but it seems desirable to qualify its specific
determination.

Superfamily CERITHIACEA
Family PROCERITHIIDAE
Genus PROCERITHIUM Cossmann 1902
Subgenus RHABDOCOLPUS Cossmann 1906

Procerithium (Rhabdocolpus) mandawaense sp. nov.
Pl. 27, figs. oa, b, moa, b; 11a, b, 124,00

DiaGnosis. Shell of medium size for the subgenus (height of largest specimens,
when complete, c. 8 mm.) ; spire angle varying from about 15°-20°. Protoconch

FROM TANGANYIKA AND KENYA 157

elevated, acute, of about 2} smooth whorls. Succeeding whorls with flat to feebly
concave outer face and broad, angularly impressed sutural region. Ornament con-
sisting of collabral ribs which extend right across the whorls except for the impressed
sutural region, and are overridden by spiral threads. Collabral ribs narrow but
moderately strong, straight or opisthocyrt to a varying extent, numbering 10-12 on
the later whorls, and separated by intervals about twice their width. Spiral threads
on spire whorls most commonly 5, more rarely 6 or even more, one forming each
border of the sutural depression ; in some specimens they are almost equal in
strength and evenly distributed, while in others they are unequal, alternating in
strength or quite irregularly arranged. Small granules situated at intersections of
collabral ribs and spiral threads are present on uppermost and lowest of the latter in
most specimens, but in a few specimens on uppermost only, and in some on inter-
mediate threads also ; strongest granules pointed, majority rounded. Base evenly
convex, ornamented with strong spiral threads. Aperture (broken in most speci-
mens) apparently evenly rounded.

HOLOTYPE AND PARATYPES. Holotype, no. GG.10290, ex B.P. Coll. Many
paratypes, including nos. GG.10291-93.

LOCALITIES AND HORIZONS. Mandawa well no. 6, Tanganyika, at the following
depths : 38-40 feet, 44-46 feet, 46-48 feet (very common), 48-50 feet, 50-52 feet
(common), 52-54 feet, 56-58 feet, 58-60 feet, 60-62 feet, 62-64 feet, 64-66 feet, 66-—
68 feet, 68-70 feet. Mandawa well no. 7, depth g2—100 feet. Bajocian (?).

REMARKS. The muricate type of ornament present in this species is found in both
the subgenera Rhabdocolpus and Xystrella, although in the more typical species of the
latter such ornament is more coarsely developed. According to Cossmann the most
important distinction between the two subgenera is that the aperture is rounded in
Rhabdocolpus and quadrangular in Xystrella ; hence, if this criterion is accepted, the
species now described must be included in Rhabdocolpus. Its ornament differs in
detail from that of any described European species.

Genus EXELISSA Piette 1860

Exelissa africana sp. nov.
Pl. 27, figs. 2a, b, 3a, b, 4a, b, 5a, b

Diacnosis. Of medium size for the subgenus (height of largest specimens about
8 mm.), conical to cyrtoconoid, acute, mean spire angle most commonly about 10°.
Protoconch finely pointed. Whorls high, tending to be loosely coiled, with flat to
feebly convex outer face and wide, well impressed sutural region. Ornament consist-
ing of collabral ribs overridden by spiral threads. Collabral ribs confined in many
specimens to adapical half of whorls and strongest near the suture, but stretching in
some specimens from suture to suture, prosocline, straight to rather strongly opistho-
cyrt ; their number, breadth and distance of spacing varying in different specimens.
Spiral threads 8-10 or more on later whorls, subequal to distinctly unequal, present
on the entire surface, although least conspicuous near the adapical suture when the
collabral ribs there are strong. When the collabral ribs are well developed small

158 JURASSIC BIVALVIA AND GASTROPODA

tubercles are present where the ribs are crossed by spiral threads. Base evenly
convex, ornamented only with strong spiral threads. Last whorl tending to become
slightly disjunct, deviated, and narrower in cross-section just before the aperture.
Aperture almost circular, but extending obliquely below the foot of the columella, so
that the inner lip is situated well to left of axis of shell.

HOLOTYPE AND PARATYPES. Holotype, no. GG.10295, ex B.P. Coll. About 50
paratypes (mostly imperfect) including nos. GG.10294, GG.10296-97.

LOCALITIES AND HORIZON. Mandawa well no. 6, Tanganyika, at depths 50-52
feet, 52-54 feet, 54-56 feet, 56-58 feet, 58-60 feet, 66-68 feet, 68-70 feet, 70-72 feet.
Near site of Mandawa well no. 1. All Bajocian (?).

REMARKS. This species could be described as an Exelissa with the ornament of a
Rhabdocolpus. It is probable that Exelissa is a polyphyletic genus, its various spe-
cies, characterised by the disjunct and deviated condition of the last whorl just before
it reaches the aperture, having been derived independently from various groups of
Procerithium. The taxonomic implications of this theory cannot, however, be ex-
plored here. After careful study of the series of specimens now described, the con-
clusion has been reached that they all belong to the same species, although the outline
of the whole shell and of individual whorls varies considerably and the Exelissa con-
dition of the apertural region of the last whorl seems to be more marked in some
specimens than in others.

Exelissa dodsoni sp. nov.
Pl. 26, figs. 1a, b

SPECIFIC NAME. After Mr. R. G. Dodson, of the Geological Survey of Kenya,
collector of the type-specimens.

DiaGnosis. Shell of medium size for the genus (usual height 6-7 mm.), conical
or slightly cyrtoconoid, spire angle about 15°. Protoconch elevated, acute, but
eroded in available specimens, so that the number of whorls forming it is uncertain.
Teleoconch whorls with flat outer face and broad, well impressed sutural region.
Ornament consisting of collabral ribs overridden by spiral threads. Collabral ribs
on most whorls narrow but prominent, orthocline or slightly prosocline, separated by
slightly broader intervals, and extending right across the outer face of the whorl, their
upper end projecting at the impressed sutural region ; they number about 12 on the
later whorls on which they are developed. On the later whorls, however, especially
the last, the lower half of each rib, or even the whole rib, tends to be only faintly
developed. Spiral threads 6—7 in number on the spire whorls, where they are mostly
unequal in strength and extend on to the sutural depression. Small granules may be
present at the intersections of the spiral and collabral elements, particularly on the
thread forming the lower border of the sutural depression. Last whorl tending to
become narrower in cross-section and slightly disjunct just before the aperture.
Base evenly convex, ornamented with spiral threads. Aperture oval, broader than
high, extending obliquely below the foot of the columella, so that the inner lip is
situated well to the left of the axis of the shell.

FROM TANGANYIKA AND KENYA 159

HOLOTYPE AND PARATYPES. The type material consists of numerous specimens
preserved in relief (but in many cases in an eroded condition) on a bedding plane of a
piece of hard limestone registered as no. G.7g1g0. A specimen represented in PI. 26,
fig. 1b (middle of left-hand side of figure) is taken as holotype.

LOCALITY AND HORIZON. Hagardulun, 25 miles N.E. of Tarbaj, N.E. Kenya ;
Bathonian—Callovian, Bur Mayo Limestones.

REMARKS. This species was originally recorded (Thompson & Dodson 1960 : 32)
as Procerithium (Rhabdocolpus) sp. The same remark applies to it as to Exelissa
africana, described above ; it is an Exelissa (as determined by the characters of the
aperture) with the ornament of a Rhabdocolpus. It is less slender than E. africana
but more strongly ribbed. The general form of the shell and the ornament are
much more similar to those of Procerithiwm (Rhabdocolpus) mandawaense, also des-
cribed above, but its costae are rather more numerous and, generally, straighter
than in that species and it has a greater number of spiral threads. Enough can be
seen of the apertural characters of P. mandawaense to show that it cannot be in-
cluded in Exelissa.

Genus PARACERITHIUM Cossmann 1902

Paracerithium lonjiense sp. nov.
Pl. 27, figs. 6a, b, 13a, b

DiaGnosis. Shell small (height of holotype 3-5 mm.), rather stoutly conical, spire
angle about 38°. Protoconch conical, with its initial whorl minute. Early whorls
evenly convex, later whorls with a well-marked shoulder separating a concave sutural
ramp, which meets the preceding whorl almost tangentially, from a feebly convex
outer face which on the later whorls is inclined inward abapically and on the last
whorl merges in an even curve with the moderately convex base. Ornament con-
sisting of strong, rounded collabral ribs which tend to form tubercles at the shoulder
on the last whorl and are crossed by spiral cords (one at the shoulder and two on the
outer face) separated by much broader intervals ; the base bears only spiral cords
which are more closely spaced than those on the remainder of the surface. Aperture
not preserved intact.

HOLOTYPE AND PARATYPES. Holotype, no. GG.10298, ex B.P. Coll. ; several
paratypes (including no. GG.10299), all but one juvenile shells.

LOCALITY AND HORIZON. Mandawa-—Lonji creek traverse, Mandawa area, Tangan-
yika ; Lower Kimmeridgian.

REMARKS. This species has the same general aspect as various representatives of
Paracerithium from the Jurassic of France figured by Cossmann (19138, pl. 13, figs.
28-63), but differs from all of them in details of ornament.

160 JURASSIC BIVALVIA AND GASTROPODA

Genus CRYPTAULAX Tate 1869

Cryptaulax bussagensis (Cossmann)
Pl. 27, figs. 10,0
1843. Cerithium pentagonum d’Archiac : 384, pl. 31, fig. 6 (nom Bronn, 1831).
1851. Cerithium pentagonum d’Archiac ; Morris & Lycett : 39, pl. 9, fig. 22.
1863. Cerithium ? neglectum Lycett : 92, pl. 44, fig. 21 (non Deshayes, 1833).
1885. Cevithium pentagonum d’Archiac ; Cossmann : 103.

1899. Cerithium bussagense Cossmann : 135.
1913b. Cryptaulax pentagonum (d’Archiac) ; Cossmann : 104, pl. 4, figs. 100-102.

MATERIAL. One specimen (no. GG.10464).

LOCALITY AND HORIZON. 2 miles W. of Tengeni (village on Pangani river), in
Mbuzi Mkubwa stream, Tanganyika ; Bathonian (?). ;

REMARKS. This specimen, a small cerithiiform shell lacking its apical whorls
but originally about 16 mm. high, has flat whorls bearing five rounded transverse
costae with intervals of about the same width. The costae are in almost uninterrup-
ted alignment on successive whorls and are very slightly prosocline. The specimen
agrees well with examples of the species from the Great Oolite of England. As
Bronn’s Cerithium pentagonum cannot be dismissed as a nomen nudum it is necessary
to find a replacement for the same name proposed by d’Archiac for the Bathonian
species. The name Cerithium bussagense was proposed by Cossmann as a substitute
name for the similarly homonymous C. neglectum Lycett, founded on a specimen
consisting merely of the earlier whorls of d’Archiac’s C. pentagonum, and it is now
adopted for this species.

Superfamily STROMBACEA
Family APORRHAIDAE Philippi 1853
Genus PIETTEIA Cossmann 1904

Pietteia stockleyi sp. nov.
P27, es7a, 0; 6,00, TAG. Use

SPECIFIC NAME. After Mr. G. M. Stockley, formerly Director of the Geological
Survey of Tanganyika.

DiaGnosis. Shell small (height of holotype, a specimen defective anteriorly,
7-9 mm.), rather slender, mean spire angle about 20°. Protoconch elevated, rather
mammilliform, of two smooth whorls. Later whorls about 54, rather high in pro-
portion to their diameter, with a moderately wide sutural ramp which forms an angle
of about 45° with the axis of the shell and an almost flat outer face, which is vertical
or even inclined inward abapically on the last whorl, and is separated from the feebly
excavated, well extended neck of the shell by an obtuse angulation. Dominant
ornament consisting of spiral threads ; three principal threads, with a secondary
thread varying in strength intercalated in each interval on the later whorls, are
present both on the outer face and on the ramp, and further threads, irregularly

FROM TANGANYIKA AND KENYA 161

spaced but alternating in strength more or less regularly, ornament the neck. In
addition, weak collabral ribs, most prominent at the ramp angle, are present except
on the last whorl, the number on the penultimate whorl being 10. On the last
whorl the ramp angle bears a short spine half a volution back from the outer lip.
Aperture narrow, not preserved intact in the available specimens. Outer lip thick-
ened, with a single short digitation at the position of the ramp angle.

HOLOTYPE AND PARATYPES. Holotype, no. GG.10359. Four paratypes, including
nos. GG.10300-01. All ex B.P. Coll.

LOCALITIES AND HORIZON. Near site of Mandawa well no. 1, Tanganyika (holo-
type). Mandawa well no. 6, from depths 46—48 feet, 58-60 feet and 60-62 feet. All
Bajocian (?).

REMARKS. Although the outer lip is imperfect even in the best-preserved speci-
men, there is little doubt that this species is a Pretteva related to P. hamus (Eudes-
Deslongchamps) (see Hudleston, 1888 : 113, pl. 4, figs. 6a-d ; pl. 7, fig. 9) and P.
unicarinata (Hudleston) (1888 : 118, pl. 4, figs. 13a—-c), both of which occur in the
Bajocian of England. It differs from these forms in details of ornament, and in P.
unicarinata the ramp angle bears two spines on the last whorl, respectively at one-
quarter and one-half of a volution back from the aperture.

Pietteia mandawaensis sp. nov.
Pl. 30, figs. 8a, b

DiAGnosis. Shell small (height of holotype, a specimen defective anteriorly, 8.0
mm.), spire slightly cyrtoconoid, its mean angle probably about 30° originally (but
affected by slight crushing in the available specimens). Protoconch bluntly conical,
of 24 smooth whorls. Later whorls about 6, of moderate height, the last three with a
fairly wide sutural ramp which forms an angle of about 45° with the axis of the shell,
and an almost flat outer face which is inclined inward abapically and on the last
whorl is separated from the feebly excavated neck of the shell by a well-marked,
obtuse angulation. Ornament consisting of spiral threads crossed by rounded
collabral ribs which are well marked on the earlier whorls but become obsolete on the
penultimate and last. Three spiral threads of primary strength are present on both
the outer face and the ramp, secondary threads of varying strength occupying their
intervals, and further threads ornament the neck. The number of collabral ribs on
the pre-penultimate whorl is about 12. On the last whorl a short spine is situated at
the ramp angle half a volution back from the outer lip. Aperture not preserved
intact.

HOLOTYPE AND PARATYPES. Holotype, no. GG.10382. Three paratypes, nos.
GG.10383-85.

LOCALITY AND HORIZON. Near site of Mandawa well no. 1 ; Bajocian (?).

REMARKS. This species resembles P. stockleyi, described above, in size and in the
nature of its ornament, but its whorls, including those of the protoconch, are much
lower in proportion to their diameter than in that species, and its collabral ribs are

162 JURASSIC BIVALVIA AND GASTROPODA

stronger and more numerous. In all four specimens crushing has increased the
apparent angle of the spire when one of the flattened sides of the shell is viewed, but
deformation of this nature does not seem to be entirely responsible for the consider-
able difference in the height of the whorls.

Pietteia dusseensis sp. nov.
Pl. 27; figs 16a;"d} ‘¢

Diacnosis. Shell rather small (height of holotype c. 13 mm.), spire moderately
broad, its angle about 25°. Protoconch unknown. Preserved whorls with a
flattened, vertical outer face separated by a rounded-off angulation from a broad
sutural ramp which forms an angle of about 45° with the axis of the shell. Orna-
ment, except on later part of last whorl, consisting of rounded collabral ribs and of
fine spiral threads overriding them ; the ribs, which are most prominent at the ramp
angle, where some swell out to form tubercles, are separated by intervals about three
times as wide ; the number on the penultimate whorl is about 12. The terminal
rib is particularly prominent, constituting a varix. Later formed part of last whorl
without ribs, but with a single prominent tuberculate carina at the ramp angle,
which forms the periphery ; base convex just below periphery, but well excavated
at the beginning of the neck of the shell ; spiral threads, separated by broader
intervals, are present on the ramp of the last whorl and on the base. Aperture
and rostrum not preserved ; the cross-section of the proximal part of a single
broken-off labral digitation is seen in the holotype.

HoLotyPe. No. G.76405. The only specimen.

LOCALITY AND HORIZON. Dussé, 14 miles S.E. of Rahmu, N.E. Kenya ; Upper
Oxfordian, Seir Limestones.

REMARKS. This species is referred to Pretteva on account of the nature of its
ornament and of the evidence that a single stout labral digitation was present. No
closely comparable Upper Jurassic species can be cited. The French Bajocian
species Piettera varispina (Schlumberger) (Piette 1867 : 100, pl. 20, figs. I-3) is more
slender and lacks tubercles on the peripheral carina of its last whorl. Such tubercles
are found on its contemporary species P. lotharingica (Schlumberger) (Piette 1867 :
105, pl. 21, figs. I-11), which, however, is a much more slender shell.

Genus HARPAGODES Gill 1869

Harpagodes aff. oceani (Brongniart)
Plt 26; fig, 3

1821. Aff. Stvombus Oceani Brongniart : 554, 570, pl. 7, fig. 2.

1867b. Aff. Pteyocera Oceani (Brongniart) ; de Loriol : 40, pl. 4, figs. 4, 5.

1891. Aff. Harpagodes Oceani (Brongniart) ; Piette: 456, pl. 45, figs. 1, 2; pl. 48, fig. 1 ;
pl. 65, figs. 5-7 ; pl. 80, fig. 1 ; pl. 81, figs. 1-3.

1910. Aff. Strombus Oceani Brongniart ; Lemoine, pl. 176.

MATERIAL. Four specimens (nos. GG.10319-22).

FROM TANGANYIKA AND KENYA 163

LOCALITIES AND HORIZON. Along Mbaru stream, 1 mile N.W. of Mbinga, Tangan-
yika. Also along Manyuli stream, just W. of Nautope and ? mile N.W. of Nautope,
Tanganyika. Callovian.

REMARKS. The best preserved specimen retains the expanded outer lip, on which
are four fairly evenly spaced rounded ribs which terminated in labral digitations
(now broken off). No doubt a further digitation, also no longer preserved, adhered
to the spire. Rounded spiral cords of secondary strength occupy the intervals
between the main ribs, three being visible in the least eroded interval. This speci-
men agrees very well with some of the above-cited figures of the typical H. oceant,
for example, Piette’s pl. 45, fig. 1, and differs from any of that author’s figures of
other species of Harpagodes. It is, of course, possible that, if perfectly preserved
specimens were available, the form now recorded would prove to differ from Brong-
niart’s species in the details of its labral digitations. H. ocean occurs typically in
Europe in the Upper Kimmeridgian (Portlandian of French authors) and is not
known from any horizon as low as Oxfordian, the latest possible age of the East
African specimens.

Harpagodes thirriae (Contejean)
PI. 28, sigs. 1,2

1860. Pterocera cavinata Contejean : 243 (non Roemer sp.).

1860. Pterocera Thirriae Contejean : pl. 9, figs. 1, 2.

1861. Pterocera Thirriai (sic) Ctj. ; Thurmann & Etallon : 133, pl. 12, fig. 109.

1861. Ptevocera Oceani Delab. ; Thurmann & Etallon : 133, pl. 12, fig. 110.

1891. Harpagodes Thirriae (Contej.) ; Piette : 452, pl. 55, figs. 2, 3 ; pl. 59, figs. 1, 2 ; pl. 68,
figs. 2-5 ; pl. 71, figs. 1, 2.

1897. Harpagodes cf. Thirriae (Contej.) ; Futterer : 615.

1960. Harpagodes oceani (Brongniart) ; Joubert, pl. 12, figs. 3a—c.

MATERIAL. Several specimens.

LOCALITIES AND HORIZONS. 103 miles S.W. of Raiya hills; N. of Figfirya,
northern Raiya hills ; 1 mile S.W. of Melka Dakacha ; 3 miles N.E. of Melka Daka-
cha ; all N.E. Kenya ; Upper Kimmeridgian, Dakacha Limestones.

REMARKS. This species is easily recognized by the broad, strongly projecting keel
which is present on the middle of the later part of the last whorl. In addition, two
faint spiral ribs are visible below this keel on the internal moulds of which the material
studied consists. There are, however, no ribs above the keel corresponding to more
posteriorly situated digitations, three of which (including the one adhering to the
spire) are shown in Piette’s pl. 71. In Europe this species has been recorded only
from the Kimmeridgian.

164 JURASSIC BIVALVIA AND GASTROPODA
Superfamily NATICACEA
Family AMPULLOSPIRIDAE Cox 1930
Genus AMPULLOSPIRA Harris 1897

Ampullospira besairiei sp. nov.
Pli-28, figs: 10; 212; bfa2d, b;:r3

SPECIFIC NAME. After Dr. H. Besairie, collector of specimens of this species from
Madagascar.

Diacnosis. Shell attaining a moderately large size for the genus (height of largest
specimen, from Madagascar, 52 mm.), height well in excess of diameter in undis-
torted specimens ; height of aperture equal to or slightly exceeding one-half of that
of shell. Apex acute, early whorls strongly and evenly convex, later whorls develop-
ing a broad, almost horizontal, slightly concave sutural shelf, separated by a rounded-
off angulation from the moderately convex outer face of the whorl. Last whorl
globose, very broadly convex at the periphery, which lies approximately along the
prolongation of the last suture, and with the evenly convex curve of its outline
continuous as far as the aperture in most specimens ; in some specimens, however,
the outline is even slightly concave near the aperture. Umbilical opening a narrow
cleft in some specimens, umbilicus perhaps absent in others. Aperture higher than
broad. Columellar lip concave, or else almost straight and leaning slightly to the
left, and forming an obtuse angle or merging in a broad curve with the parietal lip ;
margin of columellar lip narrowly reflected, with a slightly detached margin, partly
covering the umbilical cleft, and continued across the parietal region to the top of
the outer lip by the margin of a narrow but moderately thickened inductura. Outer
lip imperfect in all available specimens ; growth-lines only slightly prosocline.

HOLOTYPE AND PARATYPES. Holotype, no. GG.10304, ex B.P. Coll. Several
paratypes, including nos. GG.10305, G.65864-68, 65884-95.

LOCALITIES AND HORIZON. Lihimaliao creek, at a point near Mbaru creek,
Mandawa area, Tanganyika (type-locality) ; near site of Mandawa well no. I,
Tanganyika (young specimen) ; Mont Bory, Maevatanana district, N.W. Madagas-
car ; S.W. of geodetic point Antery, Maevatanana district, N.W. Madagascar. All
probably Bajocian.

REMARKS. This species much resembles Ampullospiva sharpei (Morris & Lycett)
(1851 : 46, pl. 11, fig. 22) from the Bathonian of England, but in that species the
spire is higher than in the form now described, the sutural shelf slopes slightly, is not
concave, and is present at an earlier stage of growth, and the last whorl is more
angular in outline. In the type species of Ampullospira, A. canaliculata (Morris &
Lycett) (1851 : 45, pl. 11, figs. 23, 23a), from the Bajocian and Bathonian of England,
the sutural shelf is narrower and the margin of the columellar lip scarcely reflected.

FROM TANGANYIKA AND KENYA 165

Ampullospira dejanira (d’Orbigny)
Pl 28, fig. 8

1852. WNatica Dejaniva d’Orbigny : 209, pl. 296, figs. 1, 2.
1960. Ampullospiva eudora (d’Orbigny) ; Joubert, pl. 12, figs. 1a, b (non d’Orbigny sp.)

MATERIAL. Several specimens (nos. G.76392-96, G.76398, G.76406-08).

LOCALITIES AND HORIZON. Wilderri hill, 11 miles S.S.W. of Rahmu, N.E. Kenya ;
low hills at Dussé, 14 miles S.E. of Rahmu, N.E. Kenya. Upper Oxfordian, Seir
Limestones.

REMARKS. The specimens included in this species are characterized by their
elevated spire, which occupies from rather more than one-third to about one-half of
the total height of the shell, by their highly and evenly convex whorls, and by the
considerable breadth of the last whorl, the maximum diameter of which much ex-
ceeds the height of the aperture and is approximately equal to the total height of the
last whorl. An umbilicus appears to be absent. The largest specimen, when com-
plete, was about 55 mm. high and the diameter of its last whorl was about 44 mm.
When first recorded, these specimens were referred to the species Ampullospira
eudora (d’Orbigny) (1852 : 211, pl. 297, figs. I-3), which has an equally elevated
spire, but they differ from that species in their relatively broader and more strongly
convex last whorl, and agree more closely with d’Orbigny’s figures of A. dejanira, a
species which he records from a number of French Upper Oxfordian localities.

Ampullospira quennelli sp. nov.
Pi, 2g, figs. 2a,.D; ¢, 32,,0,.6

SPECIFIC NAME. After Mr. A. M. Quennell, formerly Director ot the Tanganyika
Geological Survey, collector of the holotype.

DiaGnosis. Shell of medium size for the genus (height of holotype 34 mm.),
globose, height exceeding diameter. Spire slightly obtuse, its height rather less than
one-third of that of shell ; spire whorls with moderately convex outer face, separated
by a sharp angulation from a flat or slightly concave sutural ledge which is of moder-
ate width on last whorl. Last whorl broadly convex at periphery and with an evenly
convex basal outline. Umbilicus apparently absent. Growth-lines slightly prosocline.
Breadth of aperture about two-thirds of its height. Details of inner lip uncertain
(owing to obscuring matrix).

HOLOTYPE AND PARATYPES. Nos. G.g1998, GG.10324-26 respectively. There
are, in addition, several internal moulds, mostly deformed by pressure, which
probably belong to this species.

LOCALITIES AND HORIZONS. Nchia stream, 2 miles W.N.W. of Mandawa, Tangan-
yika ; Lonji stream, E.N.E. of Nandenga, Tanganyika ; both Callovian. Im-
perfect specimens from about the same horizon and probably referable to this species
are from the Lonji stream, E.N.E. of Mandenga, from the Lihimaliao stream, at a
point 4 mile E. of Njenga, and from the Mbaru stream, at a point 1 mile N.W. of

166 JURASSIC BIVALVIA AND GASTROPODA

Mbinga. Just W. of Mabokweni, 4 miles N.W. of Tanga, Tanganyika (type-locality) ;
Kimmeridgian.

REMARKS. The specimens now recorded come from two rather widely separated
horizons (Callovian and Kimmeridgian), but the material available does not justify
their reference to more than one species. The sutural ledge is a little broader in the
Kimmeridgian specimen serving as holotype than in the Callovian specimens, but
the difference is no greater than is commonly found in specimens of the same species
of Ampullospira.

The sutural ledge suggests comparison with several forms found in the Bathonian
of Europe, for example, A. gradifera (Piette) (Cossmann 1885 : 138, pl. 16, figs. 15,
16), but its lower spire distinguishes the present species from any of these forms. In
A. crithea (d’Orbigny) (1852 : 200, pl. 292, figs. 5, 6), Lower Oxfordian of France, the
shell is less globose and the sutural ledge narrower and more excavated.

A species of the genus Globularia, “‘ Natica’”’ pelops d’Orbigny (1852 : 188, pl. 288,
figs. 16, 17), from the Upper Lias of France, may be mentioned particularly as
closely resembling the present form in the general shape of the shell and in size, but
it lacks a sutural ledge.

Genus GLOBULARIA Swainson 1840

Globularia hemisphaerica (Roemer)
Pl. 28, fig. 9

1836. Nerita hemisphaerica Roemer : 156, pl. 10, figs. 7a, b.

1852. Natica hemisphaerica d’Orb. ; d’Orbigny : 204, pl. 294, figs. I, 2.

1861. Natica hemisphaerica d’Orb. ; Thurmann & FEtallon : 118, pl. 10, fig. 75.
1868. Natica hemispherica (Roemer) ; de Loriol: 43, pl. 3, figs. 3, 4.

1872. Natica hemispherica (Roemer) ; de Loriol : 118, pl. 8, figs. 4-6.

1881. Natica hemispherica (Roemer) ; de Loriol : 33, pl. 8, fig. 7.

1887. Natica hemisphaerica (Roemer) ; de Loriol: 152, pl. 16, fig. 7.

1905. Natica cf. amata d’Orb. ; Krumbeck : 127, pl. 13, figs. ga, b.

1909. Natica hemisphaerica (Roemer) ; Broésamlen : 269, pl. 20, fig. 36.

1960. Globularia hemisphaerica (Roemer) ; Joubert, pl. 12, figs. 4a, b.

MATERIAL. Four specimens (nos. G.76374, G.76384-86).

LOCALITIES AND HORIZON. Melka Dakacha, N.E. Kenya, and 3 miles to the N.E. ;
also N. of Figfirya, northern Raiya hills, N.E. Kenya. All Upper Kimmeridgian,
Dakacha Limestones.

REMARKS. This species, with its very low, obtusely rounded spire, its large last
whorl, and its wide, obliquely extended aperture, is easily recognized. In Europe
its range extends throughout the Kimmeridgian and probably into the Portlandian.

Globularia phasianelloides (d’Orbigny)
Pl, 29, figs: za, b

1852. Natica phasianelloides d’Orbigny : 212, pl. 297, fig. 6.
1872. Natica phasianelloides d’Orbigny ; de Loriol : 115, pl. 7, figs. 19, 19a.

FROM TANGANYIKA AND KENYA 167

1874. Natica phasianelloides d’Orbigny ; de Loriol: 349, pl. 8, fig. 24.
1960. Globularia phasianelloides (d’Orbigny) ; Joubert, pl. 12, fig. 5.

MATERIAL. Two specimens (nos. G.76378, G.76397).

LOCALITIES AND HORIZONS. Low hills at Dussé, 14 miles S.E. of Rahmu, N.E.
Kenya ; Upper Oxfordian, Seir Limestones. 2 miles S. of Melka Dakacha, N.E.
Kenya ; Upper Kimmeridgian, Dakacha Limestones.

REMARKS. This species is characterized by its elevated spire, which occupies
about one-third of the total height of the shell, by the feeble convexity of its whorls,
and by its relatively narrow last whorl, the maximum diameter of which is about
equal to the height of the aperture. The larger of the two specimens is about 44 mm.
high, with a diameter of 31 mm. The African specimens agree well with published
figures of specimens of the species from Europe, particularly those of de Loriol (1872).
In Europe the species occurs in the Lower Kimmeridgian.

Globularia hennigi sp. nov.
Pl. 28, figs. 5a, b, c

SPECIFIC NAME. After E. Hennig, an early worker on the Jurassic geology of
Tanganyika.

Diacnosis. Shell of small-medium size (height of holotype 16-6 mm.), globose.
Spire low, occupying about one-third of the height of the shell, coeloconoid, with the
apex very acute. Whorls strongly and evenly convex ; last whorl strongly convex
at periphery, and with an evenly convex basal outline ; maximum diameter of last
whorl slightly less than height of shell. No umbilicus. Growth-lines moderately
prosocline. (The aperture is not preserved intact.)

HoLotyPe. No. G.76391. The only specimen.

LOCALITY AND HORIZON. 2 miles S. of Melka Dakacha, N.E. Kenya ; Upper Kim-
meridgian, Dakacha Limestones.

REMARKS. This species closely resembles Natica crassitesta Dietrich (1914 : 124,
pl. 11, figs. 18a, b), from the Neocomian of Tendaguru, but has a slightly less elevated
spire. Natica venelia de Loriol (1874 : 341, pl. 8, figs. g-12), from the Portlandian
of Boulogne, France, has a slightly higher spire and strongly pronounced growth-
rugae. The French Bathonian form Natica lanceolata Piette, transferred to Ampul-
lina and figured by Cossmann (1885 : 137, pl. 3, fig. 24 ; pl. 16, fig. 32), also has a
higher spire.

Family NATICIDAE Gray 1834
Genus PICTAVIA Cossmann 1925
Pictavia tanganyicensis sp. nov.

PI, 26, tigs.ba, b,c; 7a, 6

Diacnosis. Shell small (height of largest specimen, when complete, c. 8 mm.),
ovate-conical, diameter about two-thirds of height, aperture occupying slightly less

168 JURASSIC BIVALVIA AND GASTROPODA

than one-half of total height. Protoconch conical, with minute apex. Spire acute,
conical, consisting of feebly to moderately convex, smooth whorls, abutting simply
at the sutures. Last whorl evenly and strongly convex at periphery, its outline
flattening out basally but not becoming definitely concave before reaching the aper-
ture. No distinct umbilicus. Aperture pyriform, peristome not continuous across
parietal region. Columellar lip thin, rather extended, straight or almost so, vertical
or leaning slightly to the left, and joining the basal margin in an even curve. Outer
lip defective or crushed in the available specimens, apparently almost orthocline,
although growth-lines are scarcely distinguishable on the surface of the shell.

HOLOTYPE AND PARATYPES. Holotype, no. GG.10302 ; several paratypes, in-
cluding no. GG.10303. Ex B.P. Coll.

LOCALITY AND HORIZON. Near site of Mandawa well no. 1, Tanganyika ; Bajo-
cian (?).

REMARKS. This species resembles the type-species of Pictavia, Natica pictaviensis
d’Orbigny (1852 : 191, pl. 289, figs. 8-10), from the Bajocian of France, in the general
morphology of the shell, but its small size distinguishes it both from that species and
from other Middle Jurassic representatives of the genus that have been described
previously.

(Superfamily uncertain)
Family MATHILDIIDAE
Genus PROMATHILDIA Andreae 1887

Promathildia aff. opalini (Quenstedt)
Pl. 29, figs. 6a, b

1832. Aff. Turritella elongata Zieten : 43, pl. 32, fig. 5 (non J. Sowerby, 1814).

1856. Aff. Turritella opalina Quenstedt : 326, pl. 44, fig. 15 (non Adams & Reeve 1850).
1882. Aff. Turritella opalini Quenstedt : 300, pl. 196, figs. 20, 21.

1883. Aff. Cevithium torulosi Quenstedt, pl. 205, fig. 53.

1884. Aff. Turvitella (Mathilda) opalina Quenstedt var. canina Hudleston : 200, pl. 7, fig. 9.
1891. Aff. Turritella (Mathilda) opalina Quenstedt ; Hudleston : 231, pl. 17, figs. 3a, b.

1891. Aff. Turritella (Mathilda) opalina var. canina Hudleston ; Hudleston : 232, pl. 17, fig. 4.
tg09. Aff. Turritella opalina Quenstedt : Brosamlen : 275, pl. 20, fig. 44 ; pl. 21, fig. 1.

MATERIAL. One specimen (no. GG.10270).

LOCALITY AND HORIZON. Didimtu hill, 2 miles S. of Bur Mayo, N.E. Kenya ;
Upper Lias, Toarcian, Didimtu Beds.

REMARKS. The specimen, which is 13:5 mm. high, lacks the actual apex, but
consists of about 6} early whorls of an acute, turriculate shell. The whorls, which
are strongly and evenly convex, are mostly eroded, but the last one can be seen to be
ornamented with about 8 obscurely granose spiral cords.

Hudleston (1891 : 231) suggested that Quenstedt’s name Turritella opalina might
“be accepted as a generalized term for elongate Turritellae of Jurassic age possessed
of about six or seven spirals ’’, and mentioned that the spirals were slightly granula-

FROM TANGANYIKA AND KENYA 169

ted. His “ var. camina’”’ from the Dogger (? Upper Lias, Yeovilian) of Blea Wyke,
Yorks, has eight spirals and much resembles the small shell now recorded. In
Germany Quenstedt’s species is particularly characteristic of the “ Brown Jura q”’
but ranges up into the “ Brown Jura f ” (both Aalenian), and, according to Brosam-
len, most specimens have six spirals. The age of the specimen now recorded (Toar-
cian) is slightly earlier than that of any recorded European occurrence of the species.

The specific name opalina, under which Quenstedt described this form in 1856, was
a homonym, but his emended name opalini, published in 1882, may be adopted.

Subclass OPISTHOBRANCHIA Milne Edwards
Order ENTOMOTAENIATA Cossmann
Superfamily NERINEACEA
Family NERINEIDAE Zittel 1873
Genus COSSMANNEA Pchelintsev 1927

Cossmannea hennigi (Dietrich)
PY. 20, fig. 7
1904. Nevinea Hennigi Dietrich : 134, pl. 12, fig. 6, pl. 13, figs. 3a-c.

MATERIAL. Two specimens (nos. G.48914, G.48917).

LOCALITIES AND HORIZON. Bed of Maimbwi river, and along upper part of
tributary to same river, near Tendaguru, Tanganyika ; Upper Kimmeridgian,
“ Trigonia smeet’”’ Bed and slightly below it.

REMARKS. The generic name Cossmannea is applicable to the group of species
designated as Nerinea s.str. by some previous writers, who ignored the fact that the
type-species of Nerinea should properly be taken as N. mosae Deshayes. This group
is characterized by concave whorls, a bulging sutural region, the presence of 2-3
internal folds, and the usually relatively large size of the shell.

In C. hennigi the concavity of the whorls is only moderate and no tubercles are
present on them. There are three strong internal folds. There is a close external
resemblance to Cossmannea desvoidyi (d’Orbigny) (Cossmann 1898 : 56, pl. 5, figs. 14,
21) which ranges from the Upper Oxfordian to the Tithonian in Europe. C. desvoidyi
however, has only two internal folds and is slightly more slender. The maximum
diameter of the largest specimens of C. hennigi now recorded is 29 mm.

Genus NERINELLA Sharpe 1850
Nerinella ?muelleri Cox

1900. ?Nervinea Credneri Miller : 537, pl. 17, figs. 11-13 (non Alth 1873, nec Zittel 1873).
1954. ?Nerinella muelleri Cox : 16.

MATERIAL. One specimen (no. GG.10339).

170 JURASSIC BIVALVIA AND GASTROPODA

LOCALITY AND HORIZON. Along Lihimaliao stream at a point about ? mile E. of
Njenja, Tanganyika ; Upper Oxfordian(?).

REMARKS. The type-specimens of this species came from the locality “1-5 km.
W. of the Mahokondo stream, 24:5 km. N.W. of Kiswere ’’, where the beds are now
known to be Callovian in age. The single ill-preserved fragment of a Nerinella now
recorded appears to belong to N. muelleri, but it does not allow Miiller’s published
description, referred to below in the description of N. cutlert, to be amplified.

Nerinella cutleri sp. nov.
Pl. 30, figs. 4a, b

1914. Nerinella Credneri (Miller) ; Dietrich : 142, pl. 12, fig. 8 (non Nerinea credneri Miller
1900 (non Zittel), = Nerinella muelleri Cox).

SPECIFIC NAME. After the late W. E. Cutler, the first leader of the British Museum
East African Expedition.

DiaGnosis. Shell very slender, up to about 13 cm. in length ; whorls feebly
concave to almost flat, their height approximately equal to their diameter ; earlier
whorls ornamented with very obscurely granose spiral threads, the number of which
increases to about nine at a diameter of about 5 mm. ; later whorls almost smooth.
One prominent fold low on the columella ; one prominent parietal fold occupying
the angle between the columella and the upper wall of the whorl ; one broad-based
fold, which usually is more or less quadrate in cross-section with two well-marked
inner angles, but is not definitely bifid, just below the middle of the outer wall ; and
(in some specimens only) a very weak fold on the basal wall.

HOLOTYPE AND PARATYPES. Holotype, no. G.46026, a broken specimen selected
because it retains its surface ornament. Numerous paratypes, the majority eroded.

LOCALITIES AND HORIZON. Several localities in Tendaguru neighbourhood (Ki-
pande path (type-locality), N. of Kipande, 1 mile N.W. of Tendaguru hill, scarp at
Kindope, Namapuya creek) and Kinjele, 5 miles W. of Mtapaia, N. of Tendaguru ;
Upper Kimmeridgian, Nerinella Bed. Lilomba creek and ? mile S. of Nautope, near
Tendaguru ; Upper Kimmeridgian, ‘‘ Tvigonia smeet”’ Bed. Hillside 3 miles E. of
Rahmu, south of the road to Mandera, N.E. Kenya ; Upper Oxfordian, Seir Lime-
stones.

REMARKS. The common Tendaguru Nerinella has hitherto been identified as N.
crednert (Miller), a species more correctly known as N. muellert Cox and recorded
above. This latter species has been accepted as a long-ranging one both by Dietrich
(1914 : 142) and by Hennig (1924 : 51), but this conclusion seems to need critical re-
examination. For interpretation of N. muelleri I have to rely mainly on Miller’s
description and figures. Externally, this species is very close to the Tendaguru
form both as regards whorl outline and ornament, the nodose threads which are
present on the earlier whorls disappearing at a later growth-stage, leaving the surface

FROM TANGANYIKA AND KENYA 171

almost smooth. Miiller’s fig. 12 indicates that the spiral threads ornamenting the
whorls of N. muelleri bear more conspicuous granules than have been observed in
Tendaguru specimens, but the granules may have been exaggerated by the artist.
A more noticeable difference lies in the shape of the labral fold, which Miiller’s fig. 13
shows to be relatively slender where it joins the outer lip and to split up distally into
two branches of appreciable length. In Tendaguru specimens the corresponding
fold is broad at its base and its outline is either triangular or square, at times with
slightly projecting angles. This difference, considered in conjunction with the much
higher stratigraphical horizon, seems to justify the recognition of the Tendaguru
Nerinella as a species distinct from N. muelleri. Of European species, N. danusensis
(d’Orbigny) (1852 : 118, pl. 267, figs. 4-6) has a labral fold rather similar in cross-
section to that of the Tendaguru species, but its whorls are more strongly concave
and more coarsely ornamented.

The specimens from the Seir Limestones of N.E. Kenya consist of partly weathered-
out shells on the surface of a bed of hard limestone. Their surface features are not
preserved, but erosion has exposed the internal structure of some of the shells, which
include specimens with folds agreeing well with those of N. cutleri, particularly as
regards the shape of the one on the outer lip. Other genera are also represented.

Nerinella mandawaensis sp. nov.
Fi. 30; figs. 1, 2a, 0,3

DiaGnosis. Shell very slender, the largest specimens having a maximum dia-
meter of 6-5 mm. and an estimated length, when complete, of about 10 cm. Whorls
moderately concave, with the sutural region forming a swollen band ; height of
whorls slightly exceeding their diameter. Ornament consisting of granose spiral
threads ; some specimens with four primary ones throughout, with weak interstitials,
other specimens with up to eight threads on later whorls, where they differ very little
in strength but are distributed irregularly. One not very prominent internal fold
on the lower part of the columella ; one narrow, thorn-like parietal fold occupying
the angle between the columella and the upper wall of the whorl ; and one prominent
but only moderately broad fold, widening slightly at its distal end in some specimens,
just below the middle of the outer wall.

HOLOTYPE AND PARATYPES. Nos. GG.10333, GG.10334-38 respectively, the para-
types in pieces of sandstone some containing several specimens.

LOCALITY AND HORIZON. Along Mandawa—Namakongoro stream, about I mile
W. of Mandawa, Tanganyika ; Middle-Upper Kimmeridgian.

REMARKS. The specimens are of the same age as Nerinella cutleri, from Tenda-
guru, but their recognition as a distinct species is justified by their more strongly
concave whorls and by the differences in their internal folds. The labral fold, in
particular, is narrower but more prominent than that of the Tendaguru form.

172 JURASSIC BIVALVIA AND GASTROPODA

Genus PSEUDONERINEA de Loriol 1890

Pseudonerinea clio (d’Orbigny)

Pl. 30, figs. 5, 6
18506. Chemnitzia Clio d’Orbigny : 2.
1851. Chemnitzia Clio d’Orbigny : 66, pl. 249, figs. 2, 3.
1861. Chemnitzia Clio d’Orb. ; Thurmann & Etallon : 87, pl. 6, fig. 26.
1867a. Pseudomelania Clio (d’Orbigny) ; de Loriol : 14, pl. B, fig. 1.
1887. Pseudomelania Clio (d’Orbigny) ; de Loriol : 139, pl. 14, figs. 5, 6.
1894a. Pseudonerinea Clio (d’Orbigny) ; de Loriol : 42, pl. 3, figs. 5, 6.
1898. Pseudonerinea Clio (d’Orbigny) ; Cossmann : 10, pl. 1, figs. 11, 12, 16.
1911. Pseudomelania aff. Clio (d’Orbigny) ; Blaschke : 166, pl. 4, fig. 6.

MATERIAL. Six specimens (including nos. GG.10329-31), mostly imperfect.

LOCALITY AND HORIZON. } mile E. of Nangororo, Tanganyika ; Upper Kim-
meridgian.

REMARKS. The largest of the specimens now recorded is about 57 mm. high.
The specimens agree quite well with European ones in the general form of the shell
and the relative height of the almost flat whorls. In one specimen the anterior out-
let of the aperture, which undercuts the columella, is well seen, but its canal-like
appearance is intensified by the fact that the basal lip is broken away. In the fig-
ures of P. clio published by d’Orbigny and by Thurmann & Ftallon the anterior margin
of the aperture is restored, incorrectly, as entire and evenly rounded. Cossmann
describes the aperture of P. clio as “ largement sinueuse a la base ”’ and the columella
as “‘se terminant en pointe un peu infléchie contre la sinuosité antérieure de
ouverture, sans former de bec avec le contour supérieur [i.e. the basal margin]. ”
De Loriol (1894a : 42, pl. 3, fig. 5), however, figures a specimen with an anterior out-
let very much like that of the form now described and comments upon it. Cossmann
(1898 : 4) would refer species with a canal-like outlet to Fibula rather than to Pseudo-
nerinea, but in typical species of Fibula the shell is much less slender than in forms
such as that now recorded. One of the specimens has been sectioned and shown to
be without internal folds, as in all species of Fibula and Pseudonerinea. In Europe
this species occurs in coralline beds of the Kimmeridgian stage.

Genus TROCHALIA Sharpe 1850

Trochalia depressa (Voltz)
Pl 29; fe37

1835. Nevinea depressa Voltz : 425.

1836. Nerinea depressa Voltz ; Bronn : 549, pl. 6, figs. 17a, b.

1850. Tvochalia depressa (Voltz) ; Sharpe : 107.

1851. Nevinea depressa Voltz ; d’Orbigny : 104, pl. 259 (as N. umbilicata).

1861. Nevinea depressa Voltz ; Thurmann & Etallon : 97, pl. 8, fig. 42.

1869. Cryptoplocus depressus (Voltz) ; Gemmellaro : 42, pl. 6, figs. 9-11.

1869. Cvryptoplocus umbilicatus (d’Orb.) ; Gemmellaro : 43, pl. 2 bis, figs. 18, 19.

1874. Tvochalia depressa (Voltz) ; de Loriol : 312, pl. 7, fig. 2.

1886. Tvochalia depressa (Voltz) ; de Loriol: 115, pl. 11, figs. Io, 11.

1898. Cryptoplocus depressus (Voltz) ; Cossmann: 158, pl. 11, figs. 33, 34 : pl. 12, figs. 3, 4, 7,
i fy 7

FROM TANGANYIKA AND KENYA 173

MATERIAL. Several specimens (nos. G.70517-18, G.76375-76, G.76389) preserved
in hard limestone.

LOCALITIES AND HORIZON. Melka Dakacha, 1 mile W. of Melka Dakacha, and 1
mile $.S.W. of Melka Dakacha, N.E. Kenya ; Upper Kimmeridgian, Dakacha Lime-
stones.

REMARKS. These specimens agree well with European ones in the angle of their
spire and in their very feebly convex, non-gradate whorls. The largest one was 15
cm. or more high when complete. Axial sections show the broad umbilicus and a
single, very strong internal fold, projecting from the upper wall of the whorls. In
Europe this species ranges from the Lower Kimmeridgian to the Upper Kimmerid-
gian and probably higher.

Order TECTIBRANCHA Cuvier
Superfamily BULLACEA
Family ACTEONIDAE d’Orbigny 1842
Genus ACTEONINA dOrbigny 1850
Subgenus STRIACTAEONINA Cossmann 1895

Acteonina (Striactaeonina) supraliasica sp. noy.
Pl. 29; figs..4@;.0;.¢

Diacnosis. Of medium size for the subgenus (height of largest specimen c. 15
mm.), with a relatively high and narrow, cylindrical last whorl and an acute, gradate-
conical spire, the height of which is about one-quarter of that of the shell. Whorls
with a steep, flattened ramp which forms an angle of about 60° with the horizontal
and a subvertical outer face, of which only a narrow strip is exposed on the spire. The
outline of the last whorl is broadly convex where it merges abapically into the steeply
sloping base. Outer face and base ornamented with unevenly spaced, linear spiral
grooves. Aperture very narrow adapically ; outer lip not preserved intact ; inner
lip simple, with a thin, narrowly spread, distinctly margined coating of callus.

HOLOTYPE AND PARATYPES. Nos. GG.10271 and GG.10272-74 respectively, four
specimens in all.

LOcALITY AND HORIZON. Didimtu hill, 2 miles S. of Bur Mayo, N.E. Kenya ;
Upper Lias, Toarcian, Didimtu Beds.

REMARKS. The specimens are rather eroded and it is not possible to see if the
spiral groove commonly found just below the ramp in species of Stviactaeonina is
present. The general form of the shell resembles that of some species of Cylindrites,
but the presence of spiral ornament and the absence of folds low on the columellar lip
distinguish it from that genus.

174 JURASSIC BIVALVIA AND GASTROPODA

Family AKERIDAE Cossmann 1895
Genus AKERA Miller 1776

Akera tanganyicensis sp. nov.
Pl. 29, figs. 5a, b

DiaGnosis. Of medium size (height of holotype 27:5 mm.), cylindrical, involute,
with flattened spire ; maximum diameter about three-fifths of height in holotype
(in which specimen, however, it is probably increased a little by crushing). Sutures
impressed. Sides of last whorl very feebly convex and diverging slightly in an
abapical direction as far as the periphery of the base, which lies at about the lower
third of the height of the shell, and below which the outline of the base is very feebly
convex. Aperture of moderate breadth above, where the inner lip is formed by the
steep face of the previous whorl, broadening below, where the inner lip recedes to the
columella. Outer lip vertical, curving back to a slight extent at its upper end, to
meet the suture ; basal margin of aperture forming an even curve ; columellar lip
vertical, short.

HototyPe. No. GG.10332. The only specimen.

LOCALITY AND HORIZON.. Along Mbaru stream, I mile N.W. of Mbinga, Tangan-
yika ; Callovian.

REMARKS. This form seems to be congeneric with a series of Jurassic species
which Cossmann (1896) : 127-131) includes in Acera [better, Akera], a genus origin-
ally founded on Recent forms. In A. mediojurensis Cossmann (1896b : 128, pl. 6,
figs. 8, 9), from the Callovian and Lower Oxfordian of France, the side of the last
whorl is more strongly convex and the shell is slightly broader in proportion to its
height than in the species now described. In A. truncata (Lennier), from the Kim-
meridgian of France, the shell, as figured by Cossmann (18960 : 130, pl. 6, figs. 13,
14), is even closer to the present form in shape, but is slightly more slender.

V LIST OF FOSSIL LOCALITIES, WITH SPECIES COLLECTED AT EACH
LOCALITIES IN S.E. TANGANYIKA

Tendaguru : Tingutitinguti creek, S.W. of Tendaguru hill ; Upper Kimmeridgian,
“ Trigoma smeei”’ Bed.

Cucullaea sp., Modiolus bipartitus (J. Sowerby), Mytilus (Falcimytilus) dietrich
sp. nov., Lithophaga suboblonga Dietrich, Gervillella aviculoides (J. Sowerby),
Meleagrinella radiata (Trautschold), Lima, (Plagiostoma) sp., Lima (Acesta)
cutlert sp. nov., Liostrea dubiensis (Contejean), Trigonia (Indotrigonia) smeet
auct., Hippopodium quenstedti (Dietrich), Astarte sp., Opis sp., Lucina sp.,
Mactromya sp., Protocardia schencki Miller, Protocardia (Tendagurium) pro-
pebanneiana (Dietrich), Eomiodon (Africomiodon) cutlert sp. nov., Symmetro-
capulus ? sp., Pseudomelania (Oomia) dietrichi sp. nov., Ampullospira? sp.,
Globularia sp.

FROM TANGANYIKA AND KENYA 175

Tendaguru : Maimbwi river, S.E. of Tendaguru. Upper Kimmeridgian, ‘ Tri-
gona smeet”’ Bed.

Meleagrinella radiata (Trautschold), Trigonia (Indotrigonia) smeei auct., Astarte

weissermelt Dietrich, Astarte subobovata Dietrich, Cossmannea hennigi (Dietrich).

Tendaguru : near summit of Tendaguru hill. Upper Kimmeridgian, “‘ Trigonia
smeer”” Bed.
Meleagrinella radiata (Trautschold).

100 miles
eee

fic. 1. Sketch-map of eastern Tanganyika, showing Jurassic outcrops.

176 JURASSIC BIVALVIA AND GASTROPODA

Tendaguru : excavation ““M 1”’, Tendaguru hill. Upper Kimmeridgian, Dino-
saur Bed.
Eomiodon dinosaurianum sp. nov.

Tendaguru : excavation ‘““M 7’’. Upper Kimmeridgian, “‘ Tvigonia smeei’”’ Bed.
Mytilus (Falcimytilus) dietricht sp. nov., Astarte sp.

Tendaguru : valley N.N.W. of “ D”’ flag, ? mile N. of Tendaguru hill, on road to
Kindope. Upper Kimmeridgian, “‘ Trigonia smeei’’ Bed.
Meleagrinella radiata (Trautschold), Trigonia (Indotrigonia) smeet auct., Hippo-
podium quenstedti (Dietrich).

Tendaguru : Dwanika river, N.E. of Tendaguru hill. Upper Kimmeridgian,
“ Trigonia smeei’’ Bed.
Trigonia (Indotrigonia) smeei auct., Laevitrigonia dwantkana sp. nov.

Tendaguru : beyond the N.W. flag, 1 mile N.W. of Tendaguru hill. Upper Kim-
meridgian, Nerinella Bed.
Grammatodon (Indogrammatodon) irritans (Hennig), Cucullaea sp., Gervillella
aviculoides (J. Sowerby), Stegoconcha gmuellert (Krenkel), Trigonia migeodi sp.
nov., Tvigonia (Indotrigonia) smeei auct., Hippopodium quenstedti (Dietrich),
Astarte recki Dietrich, Astarte sowerbyana Holdhaus, Nerinella cutleri sp. nov.

Tendaguru : 2000 ft. N. of Kipande N. flag, W. of Tendaguru hill. Upper Kim-
meridgian, Nerinella Bed.
Stegoconcha gmuelleri (Krenkel), Trigonia (Indotrigonia) smeei auct., Astarte recki
Dietrich, Astarte sp., Astarte sowerbyana Holdhaus, Sphaera subcorrugata Dietrich,
Homomya hortulana Agassiz, Nerinella cutleri sp. nov.

Tendaguru : 4th Kipande flag, W. of Tendaguru hill. Upper Kimmeridgian,
“ Trigomia smeei’’ Bed.
Cucullaea kipandeensis sp. nov., Grammatodon (Indogrammatodon) trntans
(Hennig), Astarte recki Dietrich, Eomiodon (A fricomiodon) cutlert sp. nov.

Tendaguru : Kipande creek, W. of Tendaguru hill. Upper Kimmeridgian,
“ Trigoma smeei’’ Bed.
Lithophaga suboblonga Dietrich.

Tendaguru : Kipande path, W. of Tendaguru hill. Upper Kimmeridgian,
Nerinella Bed.
Cucullaea kipandeensis sp. nov., Stegoconcha gmuelleri (Krenkel), Chlamys
(Radulopecten ?) sp., Lissochilus stremmet Dietrich, Nerinella cutlert sp. nov.

FROM TANGANYIKA AND KENYA 177

Tendaguru : between first and N. flags, Kipande path, W. of Tendaguru hill.
Upper Kimmeridgian, “‘ Trigonia smeei’”’ Bed.
Lopha hennigi (Dietrich), Trigonia (Indotrigonia) smeet auct., “ Pleurotomaria ’
sp.

Tendaguru : 200 yards N.E. of workings at Nguruwe, 1} miles S. of Tendaguru
hill. Upper Kimmeridgian, ‘‘ Trigonia smeei’”’ Bed.
Lithophaga suboblonga Dietrich, Trigonia (Indotrigonia) smeei auct.

,

Tendaguru : Mtapaia road, N. of Tendaguru. Upper Kimmeridgian, “ Trigonia
smeet”’ Bed.
Lopha hennigi (Dietrich), Homomya hortulana Agassiz.

Tendaguru : “ ditch 2x’, Tapaira trail, S. of Tendaguru. Upper Kimmeridgian,
“ Trigonia smeet””’ Bed.
Meleagrinella radiata (Trautschold), Liostrea sp., Astarte sp., Chrysostoma staffi
Dietrich.

Tendaguru: road 1} miles N.N.W. of Tapaira village, S.W. of Tendaguru.
Upper Kimmeridgian, “ Tvigonia smeei’’ Bed.
Hippopodium quenstedti (Dietrich).

Tendaguru : 3 miles N.N.W. of Tapaira village, S.W. of Tendaguru. Upper
Kimmeridgian, “ Tvigonia smeet”’ Bed.
Cucullaea sp., Chlamys sp., Trigonia (Indotrigonia) smeei auct., Sphaera sub-
corrugata Dietrich.

Tendaguru : Namapuya creek. Upper Kimmeridgian, Nerinella Bed.
Nerinella cutleri sp. nov.

Tendaguru : Nitongola creek. Upper Kimmeridgian, “ Trigonia smeei”’ Bed.
Meleagrinella radiata (Trautschold), Lima (Plagiostoma) sp., Lima (Acesta) cut-
lert sp. nov., Trigonia (Indotrigonmia) smeei auct., Astarte weissermeli Dietrich,
Coelastarte dietricht sp. nov., Protocardia schencki Miller, “ Patella” sp.

Tendaguru : Lilomba creek. Upper Kimmeridgian, “‘ Tvigonia smeei’”’ Bed.
Cucullaea sp., Mytilus (Falcimytilus) dietrich sp. nov., Lithophaga suboblonga
Dietrich, Chlamys sp., Chlamys (Radulopecten) kinjeleensis sp. nov., Liostrea sp.,
Trigonia (Indotrigonia) smeei auct., Astarte sp., Lucina cutleri sp. nov., Nerinella
cutlert sp. nov.

Kindope, N.N.W. of Tendaguru ; “ Kindope river’. Upper Kimmeridgian,

“ Tngoma smeei’’ Bed.
Grammatodon (Indogrammatodon) irritans (Hennig), Mytilus (Falcimytilus)
dietrichi sp. nov., Pinna constantini de Loriol, Meleagrinella radiata (Trautschold),

178 JURASSIC BIVALVIA AND GASTROPODA

Entolium corneolum (Young & Bird), Chlamys sp., Lima (Acesta) cutlert sp. nov.,
Lima (Plagiostoma) sp., Liostrea dubiensis (Contejean), Tvigonia (Indotrigonia)
dietricht Lange, Astarte weissermeli Dietrich, Lucina sp., Protocardia schencki
Miller, Scurriopsis (Dietrichiella) kindopensis (Dietrich), Lissochilus stremmei
Dietrich.

Kindope, N.N.W. of Tendaguru ; about 100 feet down scarp. Upper Kimmerid-
gian, Nerinella Bed.
Eonavicula sp. ““ B”’, Modiolus sp., Musculus kindopeensis sp. nov., Pseudolimea
duplicata (J.de C. Sowerby), Limatula migeodi sp. nov., Protocardia schencki
Miller.

Kindope, N.N.W. of Tendaguru ; 30 to 70 feet down scarp. Upper Kimmerid-
gian, Nerinella Bed.
Grammatodon (Indogrammatodon) trritans (Hennig), Lithophaga sp., Pinna con-
stantini de Loriol, Liostrea dubiensis (Contejean), Astarte sp.

Kindope, N.N.W. of Tendaguru ; bottom of scarp. Upper Kimmeridgian,
Nerinella Bed.
Stegoconcha gmuellert (Krenkel).

Kindope, N.N.W. of Tendaguru ; three-quarters of way down scarp. Upper
Kimmeridgian, Nerinella Bed.

Grammatodon (Indogrammatodon) irritans (Hennig), Apolinter kindopeensis sp.
nov., Musculus kindopeensis sp. nov., Gervillella aviculoides (J. Sowerby), Pinna
constantimi de Loriol, Trichites sp., Meleagrinella radiata (Trautschold), Entolium
corneolum (Young & Bird), Chlamys sp., Lima (Acesta) kindopeensis sp. nov.,
Pseudolimea duplicata (J. de. C. Sowerby), Liostrea dubiensis (Contejean), T71-
gonia (Indotrigonia) smeei auct., Protocardia schencki Miller, Eomiodon (A frico-
miodon) cutlert sp. nov., Nerinella cutlert sp. nov.

Kindope, N.N.W. of Tendaguru ; top of scarp. Upper Kimmeridgian, Nerinella
Bed.
Lopha hennigi (Dietrich).

Kindope, N.N.W. of Tendaguru ; Kindope river, 150 feet below “ St.’’ Upper
Kimmeridgian, Nerinella Bed.
Grammatodon (Indogrammatodon) irritans (Hennig), Gervillella aviculoides (J.
Sowerby), Pinna constantini de Loriol, Oxytoma inequivalvis (J. Sowerby),
Meleagrinella radiata (Trautschold), Bositra somaliensis (Cox), Exogyra nana
(J. Sowerby), Protocardia schencki Miller, Anisocardia kinjeleensis sp. nov.

Kindope, N.N.W. of Tendaguru. Upper Kimmeridgian, “‘ Tvigonia smeei’’ Bed.
Meleagrinella radiata (Trautschold), Placunopsis sp., Trigonia (Indotrigonia)
smeet auct.

FROM TANGANYIKA AND KENYA 179

Kindope, N.N.W. of Tendaguru. Upper Kimmeridgian, Nerinella Bed.
Lithophaga sp., Lopha? kindopeensts sp, nov.

Kinjele, 5 miles W. of Mtapaia, N. of Tendaguru. Upper Kimmeridgian, “ T7-
goma smee”’ Bed.
Mytilus (Falcimytilus) dietrichi sp. nov., Trigonia (Indotrigonia) smeet auct.

Kinjele, 5 miles W. of Mtapaia, N. of Tendaguru. Upper Kimmeridgian, Indo-
grammatodon Bed.
Grammatodon (Indogrammatodon) irritans (Hennig), Modiolus (Inoperna) per-
plicatus (Etallon), Meleagrinella radiata (Trautschold), Entolium corneolum
(Young & Bird), Liostrea sp., Protocardia schencki Miller, Antsocardia kinjele-
ensis sp. nov., Pleuromya uniformis (J. Sowerby).

N. of Kinjele, 5 miles W. of Mtapaia, N. of Tendaguru. Upper Kimmeridgian,
“ Tngonia smeei’’ Bed.
Trigoma (Indotrigonia) smeet auct.

N. of Kinjele, 5 miles W. of Mtapaia, N. of Tendaguru. Upper Kimmeridgian,
Nerinella Bed.
Chlamys (Radulopecten) kinjeleensis sp. nov., Lopha? kindopeensis sp. nov.,
Nerinella cutlert sp. nov.

3 mile S. of Nautope, 14 miles N.N.W. of Mtapaia. Upper Kimmeridgian,
“ Tnigonia smeet’”’ Bed.
Trigonia (Indotrigomia) smeet auct., Astarte weissermeli Dietrich, Nerinella
cutlert sp. nov.

Fimairo well no. 1, depths 162 to 254 feet (B.P.).. 9° 30’ 15” S., 39° 18’ 37” E.
Bajocian (?), Pindiro Shales.
Corbula pindiroensis sp. nov.

Mandawa well no. 6, depths 38 to 72 feet (B.P.). 9° 25’ 4" S., 39° 25’ 9” E.,
Bajocian (?).
Gervillella orientalis (Douvillé), 50-52 feet, Pronoella putealis sp. nov., 46-64 feet,
Corbula mandawaensis sp. nov., 46-72 feet, Coelostylina mandawaensis sp. nov.,
58-68 feet, Zygopleura mandawaenstis sp. nov., 58-66 feet, Procerithium (Rhabdo-
colpus) mandawaense sp. nov., 38-70 feet, Exelissa africana sp. nov., 50-72 feet,
Brachytrema sp., 46-54 feet, Prettera stockleyi sp. nov., 46-62 feet.

Mandawa well no. 7, depths 92-4520 feet (B.P.). 9° 24’ 58” S., 39° 25’ 3” E.
Bajocian (?).
Corbula tanganyicensis sp. nov., 3760-4520 feet, Procerithium (Rhabdocolpus)
mandawaense sp. nov., 92-100 feet.

180 JURASSIC BIVALVIA AND GASTROPODA

Lonji creek, W. of Mandawa (B.P. loc. DMM 176). 9° 21’ 40" S., 39° 24’ 22” E.
Callovian (?).

Grammatodon (Indogrammatodon) virgatus (J. de C. Sowerby), Astarte unilateralis
J. de C. Sowerby.

Lonji creek, W. of Mandawa (B.P. loc. DMM 177). 9° 21’ 47" S., 39° 24’ 25" E.
Callovian.

Thracia viceliacensis d’Orbigny.

Lonji creek, W. of Mandawa, (B.P. loc. DMM 182). 9° 22'15”S., 39° 23’ 11” E.
Upper Kimmeridgian.
Fimbria sp. “C”’.

Left bank tributary, Lonji creek, W. of Mandawa (B.P. loc. DMM 183). 9° 22’
15” S., 39° 23’ 11” E. Upper Kimmeridgian.
Astarte lonjiensis sp. nov.

Lonji creek, W. of Mandawa (B.P. loc. DMM 184). 9° 22’ 16” S., 39° 23’ 12” E.
Upper Kimmeridgian.
Astarte mandawaensis sp. nov.

Mandawa-Lonji creek traverse, Mandawa area (B.P. loc. DMM 189). 9° 21’
58" S., 39° 25’ 36” E. Lower Kimmeridgian.
Paracenithium lonjiense sp. nov.

“ Station 76’ (about 14 miles W. of Mandawa), Mandawa—Lonji creek traverse.
(B.P. loc. DMM 196). 9° 22’ 0’ S., 39° 25’ 20” E. Callovian (?).
Trigonia elongata J. de C. Sowerby.

Mandawa-—Lonji creek traverse, Mandawa area (B.P. loc. DMM 197). 9° 21’
57” S., 39° 25’ 24” E. Upper Oxfordian.

Eopecten aubryi (Douvillé), Pholadomya hemicardia Roemer, Pleuromya calcei-
formis (Phillips).

Lihimaliao creek, Mandawa area (B.P. loc. DMM 211). 9° 25’ 13” S., 39° 24’
28” E. Upper Oxfordian.

Pseudolimea mandawaensis sp. nov., Liostrea polymorpha (Minster), Astarte
sowerbyana Holdhaus.

Lihimaliao creek, near Mbaru creek, Mandawa area (B.P. loc. DMM 214). 9° 25’
30” S., 39° 26’ E. Bajocian (?), Pindiro Shales.
Parallelodon pindiroensis sp. nov., Modiolus imbricatus (J. Sowerby), Gervillella
orientalis (Douvillé), Protocardia bipi sp. nov., Protocardia besairiei sp. nov.,
Pronoella pindiroensis sp. nov., Pronoella putealis sp. nov., Ceratomya tangany1-
censis sp. nov., Thracia lens (Agassiz), Coelostyina mandawaensis sp. nov.,
Ampullospira besainie sp. nov.

FROM TANGANYIKA AND KENYA 181

Scarp stream on west-facing scarp immediately N. of Matapwa, 20 yards above
second and bigger waterfall and 550 yards W. of road, Pindiro area (B.P. loc. RS 5609).
9° 39’ 25” S., 39° 24’ 34” E. Upper Kimmeridgian.

Grammatodon (Indogrammatodon) matapwaensis sp. nov., Brachidontes (Arco-
mytilus) laitmairensis (de Loriol), Chlamys matapwaensis sp. nov., Protocardia
suprajurensis (Contejean).

Hillside overlooking Lake Mbuo, Pindiro—Ruwawa valley (B.P. loc. RS. 695).
9° 28’ 56” S., 39° 19’ 0” E. Middle Kimmeridgian.
Entolium corneolum (Young & Bird).

Mpilepile stream, 800 yards E.N.E. of Mitole road junction, northern Mandawa
area (B.P. loc. RS 814). 9° 16’ 13” S., 39° 23’ 48” E. Upper Kimmeridgian.
Opisthotrigonia curta (Aitken), Astarte weissermeli Dietrich, Seebachia janensch
Dietrich.

Mpilepile stream, below 2nd confluence on N. side, 1300 yards E.N.E. of Mitole
road junction, northern Mandawa area (B.P. loc. RS 815). 9° 16’ 3” S., 39° 24’
1” E. Upper Kimmeridgian.

Astarte mitoleensis sp. nov.

Mpilepile stream bed, running E. from Mitole, 200 yards S.E. of a point 1300 yards
E.N.E. of Mitole road junction, northern Mandawa area (B.P. loc. RS 816). 9° 15’
50” S., 39° 24’ 23” E. Upper Kimmeridgian.

Chlamys (Radulopecten?) kinjeleensis sp. nov.

Mpilepile stream bed, running E. from Mitole, just below confluence on S. side,
1650 yards N.E. of Mitole road junction, northern Mandawa area (B.P. loc. RS 817).
9° 15’ 56” S., 39° 24’ 32” E. Upper Kimmeridgian.

Nummocalcar mitoleensis sp. nov.

Kiwawa stream, 2400 yards S.E. of Mitekera survey beacon, northern Mandawa
area (B.P. loc. RS 838). 9° 14’ 44” S., 39° 19’ 36” E. Upper Kimmeridgian.
Chlamys (Radulopecten?) kinjeleensis sp. nov., Myophorella kiwawaensts sp. nov.

Near site of Mandawa well no. 1 (B.P. loc. PEK 5798). 9° 18’ 43”S., 39° 22’ 35” E.
Bajocian (?), Pindiro Shales.
Gervillella orientalis (Douvillé), Pinna buchit Koch & Dunker, Astarte kenti sp.
nov., Mactromya eamesi sp. nov., Pronoella pindiroensis sp. nov., Coelostylina
mandawaensis sp. nov., Pictavia tanganyicensis sp. nov., Ampullospira besairiet
sp. nov., Zygopleura mandawaensis sp. nov., Exelissa africana sp. nov., Piettera
sp., Acteonina sp.

About 1 mile E.S.E. of Uleka, Mavudyi-Namgaru area (B.P. loc. JOZ 189). 9°
ge 3 5-39 27 30" E. “ Jurassic ”’, stage uncertain.
Eomiodon namgaruensts sp. nov.

182 JURASSIC BIVALVIA AND GASTROPODA

N. bank of Mandawa—Namakongoro stream, between telegraph line and Lindi—
Kilwa road, about 1 mile W. of Mandawa (loc. WA 794). 9° 22’ 24" S., 39° 26’ 9” E.
M.—U. Kimmeridgian.

Bathrotomaria aitkent sp. nov.

N. bank of Mandawa—Namakongoro stream, about 1 mile W. of Mandawa (loc.
WA 812, WA 2001). 9° 22’ 24” S., 39° 26’ 6” E. M.—U. Kimmeridgian.
Pseudomelania (Oonia) aitkeni sp. nov., Nerinella mandawaensis sp. nov.

Along Mandawa—Namakongoro stream, about 200 yards above confluence with
Mandawa stream (loc. WA 817). 9° 22’ 28”S., 39° 26’ 4” E. M.—U. Kimmeridgian.
Bathrotomaria aitkent sp. nov.

Along Mandawa—Namakongoro stream, about 4 mile above confluence with Man-
dawa stream (loc. WA 823). 9° 22’ 40” S., 39° 26’ 2” E. M.—U. Kimmeridgian.
Bathrotomaria aitkent sp. nov.

About 1 mile N. of Manyuli, near Lindi—Kilwa road (loc. WA 944). 9° 17’ 58’S.,
39° 24’ 6” E. M.—U. Kimmeridgian.
Pseudomelania vittata (Phillips).

14 miles N.W. of Mandawa (loc. WA 971). 9° 21’ 34” S., 39° 26’ 3” E., M.-U.
Kimmeridgian.
Lissochilus stremmei Dietrich.

4 mile up Nchia stream, 2 miles W.N.W. of Mandawa (loc. WA 1005, 1180). 9°
2x" 26" S.> 30°25" 10" E> €allowian:
Astarte aitkent sp. nov., Pseudomelania aspasia (d’Orbigny), Bourguetia sae-
mann (Oppel), Ampullospira quennelli sp. nov., Nerineidae, gen. et sp. indet.

# mile N.W. of Mbinga (loc. WA 1156). 9° 25’ 43” S., 39° 26’ 39” E. Upper
Kimmeridgian. :
Purpurotdea aff. gigas (Thurmann & Etallon).

Along Lonji—Runjo stream at a point 14 miles W. of Mandawa (loc. WA 1220).
O° 22) 2°S4130" 25) 22 EE. Callovian:
Pseudorhytidopilus lonjiensis sp. nov.

Along Lonji stream, a little E.N.E. of Nandenga hill (loc. WA 1287). 9° 21’ 44"S.,
39° 24’ 25” E. Bathonian—Upper Oxfordian part of Mandawa—Mahokondo Series ;
probably Callovian.

Globularia sp.

Along Lonji stream, a little E.N.E. of Nandenga hill (loc. WA 1345). 9° 21’ 46’S.,
39° 24’ 29” E. Callovian.
Pseudomelania aff. aspasia (d’Orbigny), Ampullospira quennelli sp. nov.

FROM TANGANYIKA AND KENYA 183

Along Lonji stream, a little E.N.E. of Nandenga hill (loc. WA 1346). 9° 21’ 48’S.,
39° 24’ 26” E. Callovian.
Ampullospira quennelli sp. nov.

Along Mbaru stream, 1 mile N.W. of Mbinga (loc. WA 1634). 9° 25’ 36” S., 39°
26’ 16” E. Callovian.
Harpagodes aff. oceani (Brongniart), Akera tanganytcenstis sp. nov.

Mpilipili stream at a point about I mile N.E. of Mitole (loc. WA 1691). 9° 15’ 40”
S., 39° 24’ 38” E. Upper Kimmeridgian.
Chartronella mitoleensis sp. nov.

Along Lihimaliao stream at a point about 3? mile E. of Njenja (loc. WA 1817).
9° 25’ 17” S., 39° 24’ 26” E. Upper Oxfordian (?). (A nearby locality was dated as
Upper Oxfordian on ammonite evidence.)

Grammatodon (Indogrammatodon) virgatus (J. de C. Sowerby). Nerinella?
muellert Cox.

Along Nchia stream, 3 mile E. of Lonji (loc. WA 2013). 9° 21’ 25" S., 39° 24’ 45” E.
Bathonian—Upper Oxfordian part of Mandawa—Mahokondo Series ; probably
Callovian.

Globularia sp.

4 mile S. of Madaraha (loc. WA 2158). 9° 20’ 54”S., 39° 23’ 24” E. Middle-Upper
Kimmeridgian.
“ Pleurotomania”’ sp.

Manyuli stream at a point just W. of Nautope, Mandawa—Mahokondo anticline
Gec. VW A.2162). 9° 17’ 40” S., 39° 23’ 35” E. Callovian.
Eopecten aubryi (Douvillé), Entolium corneolum (Young & Bird), Harpagodes aff.
oceam (Brongniart).

Along Nunga stream, a short distance upstream from confluence with Manyuli
stream, ? mile N.W. of Nautope (loc. WA 2258). 9° 17’ 23”S., 39° 23’ 11” E. Bath-
onian—Upper Oxfordian part of Mandawa—Mahokondo Series ; probably Callovian.

Harpagodes aff. oceant (Brongniart).

About 1 mile E. of Manyuli (loc. WA 2261). 9° 19’ 10” S., 39° 26’ 10” E. Upper
Kimmeridgian.
“ Pleurotomaria’’ sp.

E. of Bwatabwata village, Pindiro area (loc. WA 2273). 9° 29’ 48” S., 39° 17’ 47”
E. (Aitken 1961 : 17). Bajocian (?), Pindiro Shales.
Protocardia sp.

184 JURASSIC BIVALVIA AND GASTROPODA

Along Namakumbira stream, } mile E. of Madaraha (loc. WA 2296). 9° 20’ 26’S.,
39° 23' 52” E. Bathonian—Upper Oxfordian part of Mandawa—Mahokondo Series.
Amphitrochus ? sp.

Along Namakumbira stream, 4 mile N. of Madaraha (loc. WA 2298). 9° 20’ 18”
S., 39° 23'45” E. Bathonian—Upper Oxfordian part of Mandawa—Mahokondo Series.
“ Pleurotomaria’”’ sp.

4 mile E. of Nangororo (loc. WA 2305). 9° 31’ 10” S., 39° 19’ 51” E. Upper
Kimmeridgian.
Pseudonerinea clio (d’Orbigny), Globularia aff. phasianelloides (d’Orbigny).

Namakambe stream, Mandawa—Mahokondo anticline (loc. WA 2307). 9° 23’ 32”
S., 39° 24’ 40” E. Probably Callovian.
Chlamys (Spondylopecten?) badiensis Cox.

Mbaru stream, N.E. of Nondwa and about 4 mile upstream from crossing of tele-
graph line, Mandawa—Mahokondo area (loc. WA 2349). 9° 25’ 16" S., 39° 25’ 48” E.
Bajocian (?), Pindiro Shales.

Corbula ? sp., Procerithiidae.

Tributary of Namakumbira stream, 1 mile S.E. of Mkomore, Mandawa—Mahokondo
area (locs. WA 2377, WA 2378). 9° 19’ 0" S., 39° 23’ 28” E. Bajocian (?), Pindiro
Shales.

Astarte pindiroensis sp. nov., Corbula sp.

LOCALITIES IN THE HINTERLAND OF DAR ES SALAAM AND BAGAMOYO,
TANGANYIKA

Quarries about 1 mile N.N.E. of Ngerengere, Central Railway. 6° 45’S., 38° 8’ E.
(Quennell e¢ al., 1956 : 126). Bajocian (?).
Mytilus? sp., Bakevellia ivaonensis (Newton), Eomiodon baroni (Newton),
Eomiodon tanganyicensis sp. nov., Tancredia sp.

14 miles N.N.W. of Kidugallo, Central Railway (B.P. loc. JCS 108). 6° 46’ 15"S.,
38° 12’ 48” E. Bajocian.
Trigonia kidugalloensis sp. nov., Pronoella kidugalloensis sp. nov.

24 miles N.N.W. of Kidugallo, Central Railway (B.P. loc. JCS 124). 6° 45’ 35’S.,
38° 13’ 30” E. Bajocian.
Pseudomelania (Oonia) kidugalloensis sp. nov., Coelostylina stockleyi sp. nov.

Magole, 5 miles N.W. of Kidugallo, Central Railway (B.P. loc. JCS 114, 115, 116,
117)... 6° 44’ 22’ S.,,38° 15’ 15’ 4B. Bajocian,

FROM TANGANYIKA AND KENYA 185

Trigoma costata Parkinson, Eotrapeztum? kenti sp. nov., Corbula kidugalloensis
sp. nov.

6 miles N.W. of Kidugallo, Central Railway (B.P. loc. JCS 120). 6° 44’ 35” S.,
38° 8’ 37” E. Bajocian.
Eomiodon baron (Newton), Corbula eamesi sp. nov.

6 miles N.W. of Kidugallo, Central Railway (B.P. loc. JCS 155). 6° 44’ 35” S.,
38° 8’ 10” E. Bajocian.
Trigonia kenti sp. nov.

Kidugallo Station, Central Railway. 6° 47’ S., 38° 12’ 30” E. (Quennell e al.,
1956 : 186). Bajocian, Station Beds.
Grammatodon sp., Modiolus anatinus Smith, Pinna sp., Bositra buchi (Roemer),
Entolium sp., Chlamys sp., Lima (Plagiostoma) sp., Lucina despecta Phillips,
Mactromya sp., Pholadomya lirata (J. Sowerby), Osteomya dilata (Phillips).

Rest house, Kidugallo, Central Railway. 6° 47’ S., 38° 12’ 30” E. (Quennell e¢ al.,
1956 : 186). Bajocian, Station Beds.

Grammatodon sp., Parallelodon sp., Astarte sp., Mactromya ? sp., Protocardia sp.,

Eotrapezium ? sp., Tancredia sp., Ceratomya sp., Ataphrus aff. acmon (d’Orbigny).

Borehole 5 miles N. of Kidugallo, Central Railway. 6° 43'S., 38° 12’ E. (Arkell
1956 : 330). Lower Bajocian (Aalenian).
Bositra bucht (Roemer).

1} miles E. of Kidugallo Station, Central Railway (loc. M 47). 6° 47’S., 38° 13’ E.
Bajocian, Station Beds.
Modiolus anatinus Smith, Chlamys sp., Lopha gregarea (J. Sowerby), Astarte sp.,
Lucina despecta Phillips, Fimbria kidugalloensis sp. nov., Protocardia sp.,
Pholadomya livata (J. Sowerby), Goniomya trapezicostata (Pusch), Thracia sp.

3 miles N.E. of Kidugallo Station, Central Railway (loc. M 46). 6° 46’ S., 38° 14’
E. Bajocian, Station Beds.
Lima (Plagiostoma) sp., Globularia sp.

2 miles W. of Magindu Station, Central Railway (loc. M 48). 6° 49’S., 38° 17’ E.
About Bathonian.

Liostrea dubiensis (Contejean).

I mile W. of Magindu Station, Central Railway (loc. M 49). 6° 49’ S., 38° 18’ E.
About Bathonian.

Liostrea dubiensis (Contejean).

186 JURASSIC BIVALVIA AND GASTROPODA

Magindu, Central Railway (B.P. loc. PEK 5805). 6° 48’ 45” S., 38° 19’ 7” E.
Callovian.
Liostrea (Catinula) alimena (d’Orbigny), Ceratomya pittiert (de Loriol).

E. of Magindu Station, Central Railway (loc. D 30), 6° 49’ S., 38° 20’ E. Callo-
vian.
Liostrea sp.

About 2 km. E. of Magindu, Central Railway (B.P. loc. PEK 5806). 6° 49’ S.,
38° 20’ 15” E. Callovian.
Liostrea (Catinula) alimena (d’Orbigny).

2 miles E. of Magindu Station, Central Railway (loc. D 31). 6° 49’ S., 38° 22’ E.
Callovian.
Ceratomyopsis basochiana (Defrance), Pholadomya lirata (J. Sowerby).

2 miles E. of Magindu Station, Central Railway (locs. D. 34, D 36). 6° 49’ S.,
38° 21’ E. Callovian.
Trigonia (Frenguelliella) tealei Cox, Astarte muellert Dacqué, Pholadomya livata
(J. Sowerby).

Changogo—Magindu track, 4 miles from Changogo town (B.P. loc. PEK 5801).
Callovian.
Protocardia consobrina (Terquem & Jourdy).

Borehole at Lugoba. Lower Bajocian (Aalenian).
Bositra buchi (Roemer).

Top of hill N. of Lugoba on Msata road (B.P. loc. RBH 671). 6° 22’ 7”S., 38° 21’
47” E. Callovian (?).
Praeconia rhomboidalis (Phillips).

S. of Tarawanda, 11 miles S.E. of Lugoba (locs. B 3, B 4, B 5) (Quennell e¢ al., 1956:
181). Callovian.
Grammatodon (Indogrammatodon) stockleyt Cox, Gervillella? sp., Meleagrinella
echinata (Smith), Chlamys subtextoria (Minster), Trvigonia (Frenguelliella) teale
Cox, Neritoma (Neridomus) aff. gea (d’Orbigny), Pseudomelania (Oonia) sp.

} mile from Msata on road to Bagamoyo (B.P. loc. PEK 5406). 6° 19’ 45”S., 38°
23 30” E. Callovian or Oxfordian.
Lopha eruca (Defrance).

24 miles N. of Msaka road junction, Bagamoyo district (B.P. loc. JOZ 465). 6° 17’
30” S., 38° 23’ 37” E. Callovian.
Entolium briconense (Cossmann).

FROM TANGANYIKA AND KENYA 187

Usigiwa river, 6 miles W.S.W. of Kiwangwa, Bagamoyo hinterland (loc. BM 29).
0-24" 19” S., 38° 30’ 23” E. Upper Oxfordian.
Parallelodon sp., Pteria tanganyicensis sp. nov., Meleagrinella radiata (Traut-
schold), Limatula moorei sp. nov., Trigomia (Frenguelliella) tealer Cox, Astarte
episcopalis de Loriol, Fimbria quennelli sp. nov., Isocyprina? sp., Pseudotrapezium
sp., Cercomya sp.

Scarp face, eastern margin of Makoko plain, ? mile S. of Wami river, Bagamoyo
hinterland (loc. BM 43). 6° 16’ 0” S., 38° 30’ 47” E. Upper Oxfordian.
Entolium corneolum (Young & Bird), Protocardia? sp., Pleuromya uniformis (J.
Sowerby), Bourguetia saemanm (Oppel).

In small stream on scarp face, eastern margin of Makoko plain, 1 mile S. of Wami

river, Bagamoyo hinterland (loc. BM 45). 6° 16’ 14” S., 38° 30’ 50” E. Oxfordian.

Grammatodon (Indogrammatodon) stockleyt Cox, Trichites sp., Trigonia (Fren-
guelliella) tealet Cox, Goniomya literata (J. Sowerby).

Top of scarp face on eastern margin of Makoko plain, 1} miles S. of Wami river,
Bagamoyo hinterland (loc. BM 46). 6° 16’ 41” S., 38° 31’ 0” E. Oxfordian.
Pleuromya untformis (J. Sowerby).

Kiwate—Mkange track 5 miles S.S.E. of Mkange (loc. BM 95). 6° 7’ 37” S., 38°
34’ 52” E. Oxfordian—Kimmeridgian.
Meleagrinella radiata (Trautschold), Liostrea dubiensis (Contejean), Exogrya nana
(J. Sowerby), Astarte sp., Fimbria sp.

Look-out hill opposite Kingura village, $ mile N. of Wami river, Bagamoyo hinter-
land (loc. BM 144). 6° 14’ 25” S., 38° 30’ 58” E. Upper Oxfordian.
Gryphaea hennigi Dietrich.

LOCALITIES IN N.E. TANGANYIKA

64 miles N.E. of Pande (village on Mkwaja—Mkata road) and 2} miles N. of
Msangasi stream (loc. BM 292A). 5° 45’ 15” S., 38° 39’ 10” E. Callovian.
Oxytoma? sp., Pinna muitis Phillips, Chlamys (Aequipecten) cf. palinurus
(d’ Orbigny), Chlamys sp.

Nearly 2} miles S.S.W. of Tengeni (village on Pangani river), in southernmost
headwater tributary of Mbuzi Mkubwa stream (loc. BM 330). 5° 25’ 39” S., 38° 39’
33” E. Age uncertain.

Bositra bucht (Roemer).

188 JURASSIC BIVALVIA AND GASTROPODA

5° 24’ 42"'S., 38° 39’ 35" EB." Bathonian (?).

mann), “‘ Nerinea”’ sp., Naricopsina sp.

14 miles W.N.W. of Mremere (village on Pangani river) (loc. AT 431).
38° 50’ 14” E. Upper Oxfordian.

5° 24’ 0” Si
Rollieria ? sp., Lopha sp.

About 5 miles N.E. of Tengeni (village on Pangani river), at S. end of divide

2 miles W. of Tengeni (village on Pangani river), in Mbuzi Mkubwa stream (loc.
BM 333).
Pseudomelania (Oonta) conica (Morris & Lycett), Cryptaulax bussagensis (Coss-

separating western tributary from main Maweni valley (loc. BM 369).
38° 44’ 51” E. Upper Jurassic.

Entolium cingulatum (Goldfuss).

Chinamba, ? mile S. of Amboni quarries, Tanga (B.P. loc. ANT 4506).
39° 3 3° E. Callovian.
Oxytoma inequivalvis (J. Sowerby), Trigonia (Frenguelliella) tealei Cox.

3 mile N.W. of bridge over Mkulumuzi river, 2 miles W. of Tanga (B.P. loc. PEK
5402). 95. 3.42 S:, 30° 3.25 E. “‘Callovian:
Grammatodon (Indogrammatodon) virgatus (J. de C. Sowerby), Chlamys (Spondy-
lopecten ?) badiensis Cox, Gomiomya trapezicostata (Pusch), Modiolus bipartitus
J. Sowerby.

Just W. of Mabokweni, 4 miles N.W. of Tanga (loc. QA 384). 5° 1’ 23”S., 39° 3’
o” E. Kimmeridgian.

Gervillella aviculoides (J. Sowerby), Myophorella quennelli sp. nov., Mactromya
quadrata (Roemer), Pholadomya protei (Brongniart), Ampullospira quennelli sp.
nov.

LOCALITIES IN THE COASTAL DISTRICT OF KENYA

Plantations N. of Dakatcha village, Malindi district (locs. 66/337, 66/338). 3° 00’
S., 39° 48’ E. (Williams 1962 : 17). Boulders, not im situ. Upper Jurassic.
Meleagrinella radiata (Trautschold), Chlamys? sp., Quenstedtia? sp., Isocyprina sp.

¢ mile E. of Merikano, Malindi district (loc. 66/129). 3°8'S., 39°50’ E. (Thomp-
son 1956: 18). Boulders, not im situ. Upper Jurassic.
Meleagrinella radiata (Trautschold).

2 miles N.E. of Dakatcha, Malindi district (loc. 66/150).

2° 59’ S.,. 39° 4Q—qame
Boulders, not im situ. Upper Jurassic.
Meleagrinella radiata (Trautschold).

5 22a Se

5" 4138.93

FROM TANGANYIKA AND KENYA 189

Chamgamwe, near Mombasa. c. 4° 2’S., 39°38’ E. Kimmeridgian, Chamgamwe
Shales.
Lopha solitaria (J. de C. Sowerby).

Kaya Kauma, 8 miles W. of Kilifi. 3° 37’ S., 39° 44’ E. (Parsons 1929 : 69).
Callovian, Miritini Shales.
Bositra buch (Roemer).

LOCALITIES IN N.E. KENYA

Didimtu hill, 2 miles N.E. of Bur Mayo (locs. 23/12, 23/355-357). 2° 57’ N.,
40° 16’ EF. (Ayers 1952 : 27 ; Thompson & Dodson 1960 : 20-24). Upper Lias,
Toarcian, Didimtu Beds.

Nuculana (Dacryomya) thompsoni sp. nov., Nuculana (Ryderia) kenyana sp. nov.,
Rollierta aequilatera (Koch & Dunker), Grammatodon kenyanus sp. nov., Modiolus
(Inoperna) sowerbianus (d’Orbigny), Gervillella didimtuensis sp. nov., Weyla
ambongoensis (Thevenin), Lopha costata (J. de C. Sowerby), Lopha olimvallata
nom. nov., Astarte lurida J. Sowerby, Astarte puifreyi sp. nov., Astarte didimtu-
ensis sp. nov., Astarte subminima sp. nov., Astarte sp., Astarte (Leckhamptonia)
hobleyi sp. nov., Lucina sp., Protocardia africana sp. nov., Anisocardia arkelli sp.
nov., Amsocardia didimtuensis sp. nov., Anisocardia ayersi sp. nov., Eotrapezium?
africanum sp. nov., Eotrapezium ? thompsoni sp. nov., Corbula didimtuensis sp.
nov., Pholadomya reticulata Agassiz, Pleuromya didimtuensis sp. nov., Disco-
helix didimtuensis sp. nov., Africoconulus kenyanus sp. nov., Trochopsidea
africana sp. nov., Hamusina thompson sp. nov., Purpuroidea supraliasica sp.
nov., Promathildia aff. opalint (Quenstedt), Acteonina (Striactaeonina) supra-
liasica sp. nov.

Camel track about 5 miles S. of Singu and g miles E. of Tarbaj (loc. 23/112). 2°
13’ N., 40° 16’ E. (Thompson & Dodson 1960 : 23). Toarcian or Bajocian, top of
Didimtu Beds, just below Bur Mayo Limestones.

Nuculana (Praesaccella) camelorum sp. nov.

2 miles W. of Melka Biini and 16 miles W.N.W. of Rahmu (loc. 8/8). 4° 3’ N.,
41° 2’ E. (Joubert 1960 : 12). Bathonian, Murri Limestones.
Brachidontes (Arcomytilus) asper (J. Sowerby), Chlamys curvivarians (Dietrich),
Lima (Plagiostoma) buiniensis sp. nov., Ostrea (Liostrea) sp.

Hagardulun, 25 miles N.E. of Tarbaj (loc. 23/116). 2° 29’ N., 40° 22’ E. (Thomp-
son & Dodson 1960 : 32). Bathonian—Callovian, Bur Mayo Limestones.
Nuculana (Dacryomya) dodsoni sp. nov., Brachidontes (Arcomytilus) sp., Lima
(Plagiostoma) sp., Trigonia sp., Pholadomya ovalis (J. Sowerby), Ceratomya sp.
Exelissa dodsoni sp. nov.

190 JURASSIC BIVALVIA AND GASTROPODA

39° 4°
cri Melka

Dakacha *
re =e

E

Fic. 2. Sketch-map of eastern Kenya, showing Jurassic outcrops.

FROM TANGANYIKA AND KENYA 191

Kurawe, 2 miles E. of Hagardulun, 25 miles N.E. of Tarbaj (loc. 23/78). 2° 29'N.,
40° 25’ E. (Thompson & Dodson 1960 : 32). Bathonian—Callovian, Bur Mayo Lime-
stones.

Lima (Plagiostoma) sp., Thracia sp.

1 mile N. of Asaharbito, 28 miles N. of Wergudud (loc. 15/28). 3° 33’ N., 40°
57 E. (Ayers 1952 : 22 ; Thompson & Dodson 1958 : 21). Bathonian [? or Callo-
vian], Asaharbito Beds.

Nucula sp., Grammatodon sublaevigatus (Zieten), Barbatia sp., Liostrea dubiensis
(Contejean), Tvigonia cf. brevicostata Kitchin, Astarte ayersi sp. nov., Sphaeriola
madridi (d’Archiac), Isocyprina ? sp., Anisocardia ? sp., Corbula asaharbitensis sp.
nov., Avcomya? sp., Pleuromya sp., Cuspidaria ayersi sp. nov., Aporrhaidae, gen.
indet.

34 miles W. of Melka Bini and 17 miles W.N.W. of Rahmu, hills N. of Rahmu—
Melka Murri road (loc. 8/7). 4° 3’ N., 41° 1’ E. (Joubert, 1960 : 15). Callovian,
Rukesa Shales.

Eopecten aubryi (Douvillé), Chlamys curvivarians (Dietrich), Lopha gregarea
(J. Sowerby), Lopha costata (J. de C. Sowerby), Liostrea (Catinula) alimena
(d’Orbigny), Mactromya aequalis Agassiz, Protocardia sp., Homomya inornata
(J. de C. Sowerby), Ceratomya concentrica (J. de C. Sowerby), Globularia sp.,
Cylindnites ? sp.

34 miles W. of Melka Biini and 17 miles W.N.W. of Rahmu, hills N. of Rahmu—
Melka Murri road (loc. 8/5). 4° 3’ N., 41° 1’ E. (Ayers 1952 : 24 ; Joubert 1960 :
13). Callovian, Rukesa Shales.

Lopha sp., Fimbria sp., Protocardia sp., Quenstedtia sp.

3 miles W. of Melka Biini and 16 miles W.N.W. of Rahmu, hills N. of Rahmu-—
Melka Murri road (loc. 8/9). 4° 3’ N., 41° 1’ 30” E. Callovian, Rukesa Shales.
Lopha sp., Pholadomya lirata (J. Sowerby), Cercomya sp.

13 miles W. of Rahmu, hills 4 miles S. of road to Melka Murri (loc. 16/178). 3°
58’ N., 41° 2’ E. (Joubert 1960 : 15). Callovian, Rukesa Shales.
Lopha gregarea (J. Sowerby), Fimbria sp. “‘ A’’, Pholadomya sp.
13 miles W. of Rahmu, hills 2 miles S. of road to Melka Murri (loc. 16/179). 3°
59’ N., 41° 2’ E. (Joubert 1960 : 15). Callovian, Rukesa Shales.
Lima (Plagiostoma) cf. schardti de Loriol, Lopha gregarea (J. Sowerby), Cerato-
myopsis basochiana (Defrance), Anisocardia minima (J. Sowerby).

11 miles W. of Rahmu, hills S. of road to Melka Murri (loc. 16/176). 3° 59’ N.,
41° 5’ E. (Joubert 1960 : 15). Callovian, Rukesa Shales.
Eonavicula sp., Eopecten sp., Chlamys sp., Lima (Plagiostoma) sp., Lopha gre-
garea (J. Sowerby), Mactromya sp., Fimbria sp. ‘‘ A’’, Protocardia sp.

192 JURASSIC BIVALVIA AND GASTROPODA

Bed of Muddo river, 4 miles S.W. of Muddo Erri (loc. 16/195). 3° 53’ N., 41° 0’ E.
(Joubert 1960 : 18). Callovian [?-Lower Oxfordian], Muddo Erri Limestones.
Lima (Plagiostoma) sp., Eligmus rollandi Douvillé, Fimbria sp., Mactromya sp.,
Globularia sp.

Kulong, 2 miles S.W. of Muddo Erni, 12 miles W. of Rahmu (loc. 16/189). 3° 54’
N., 41° 2’ E. (Joubert 1960: 18). Callovian [?-Lower Oxfordian], Muddo Erri
Limestones.

Brachidontes (Arcomytilus) asper (J. Sowerby), Brachidontes (Arcomytilus) lait-
matrensis (de Loriol), Eligmus rollandi Douvillé, Entolium corneolum (Young &
Bird), Eopecten aubryi (Douvillé), Camptonectes auritus (Schlotheim), Chlamys
curvivarians (Dietrich), Lima (Plagiostoma) cf. biiniensis sp. nov., Lima (Plagio-
stoma) cf. gumaraensis Cox, Lima (Plagiostoma) cf. schardti de Loriol, Lima
(Plagiostoma) sp., Pseudolimea duplicata (J. de C. Sowerby), Liostrea sp., Liostrea
(Catinula) alimena (d’Orbigny), Trigonia sp., Lucina cf. lirata Phillips, Mactro-
mya aequalis Agassiz, Fimbria sp. ““ B’’, Protocardia sp., Ceratomyopsis basochi-
ana (Defrance), Pholadomya ovalis (J. Sowerby), Pholadomya sp., Ceratomya
concentrica (J. de C. Sowerby).

Muddo Erri, 12 miles W. of Rahmu (loc. 16/172). 3° 56’ N., 41° 4’ E. (Joubert
1960 : 18). Callovian [?-Lower Oxfordian], Muddo Erri Limestones.
Eonavicula sp. ““A’’, Eligmus rollandi Douvillé, Eopecten aubryi (Douvillé),
Chlamys sp., Lima (Plagiostoma) muddoensis sp. nov., Mactromya aequalis
Agassiz, Fimbria sp. “ A’’, Fimbra sp. “ B”’, Protocardia ? sp.

14 miles W.S.W. of Rahmu (loc. 16/41). 3° 52’ N., 41° 2’ E. (Ayers 1952 : 23).
Callovian [?-Lower Oxfordian], Muddo Erri Limestones.

Eligmus rollandi Douvillé, Lima (Plagiostoma) sp., Exogyra? sp., Mactromya

aequalis Agassiz, Fimbria ? sp., Homomya sp., Ceratomya wimmisensis Gilliéron.

g miles W. of Rahmu, hills S. of Rahmu—Melka Murri road (loc. 16/175). 3° 59’
N., 41° 6’ E. Callovian [?-Lower Oxfordian], Muddo Erri Limestones.
Lima (Plagiostoma) sp., Fimbria sp. “ A”’.

10 miles W. of Rahmu, top of hills S. of Rahmu—Melka Murri road (loc. 16/139).
3° 59 N., 41° 5’ E. Callovian [?-Lower Oxfordian], Muddo Erri Limestones.
Camptonectes auritus (Schlotheim), Chlamys curvivarians (Dietrich), Liostrea
(Catinula) alimena (d’Orbigny), “ Pleurotomaria’”’ sp., Nerineidae, gen. indet.

6 miles W. of Rahmu, hillside S. of Rahmu—Melka Murri road (loc. 16/162). 3° )

58’ N., 41° 9’ E. Callovian [?-Lower Oxfordian], Muddo Erri Limestones.
Eligmus rollandi Douvillé, Eopecten aubryi (Douvillé), Lima (Plagiostoma) sp.,
Lopha gregarea (J. Sowerby), Lopha costata (J. de C. Sowerby).

FROM TANGANYIKA AND KENYA 193

River section west of Rahmu—E] Wak road, 54 miles S.W. of Rahmu (loc. 16/164,
16/146). 3°52’ N., 41° 12’ E. (Joubert 1960 : 20). Oxfordian, Rahmu Shales.
Grammatodon (Indogrammatodon) sp., Lopha solitaria (J. de C. Sowerby),
Protocardia rahmuensts sp. nov.

64 miles S.S.W. of Rahmu (loc. 16/44). 3° 52’ N., 41° 10’ E. (Ayers 1952 : 26).
Oxfordian, Rahmu Shales.
Lopha sp., Lopha gregarea (J. Sowerby), Lopha cf. intricata (Contejean).

12 miles S.W. of Rahmu (locs. 16/66, 16/67). 3° 54’ N., 41° 12’ E. (Ayers 1952 :
25). Oxfordian, Rahmu Shales.
Lopha gregarea (J. Sowerby), Lopha solitaria (J. de C. Sowerby).

24 miles S.W. of Rahmu (loc. 16/64). 3° 52’ 30” N., 41° 12’ E. (Ayers 1952 : 25 ;
Joubert 1960 : 19). Oxfordian, Rahmu Shales.
Mytilus (Falcimytilus) jurensis Roemer, Stegoconcha sp., Camptonectes auritus
(Schlotheim), Lima (Plagiostoma) rahmuensis sp. nov., Exogyra nana (J.
Sowerby), Isocyprina sp.

Uacha, 6 miles S. of Rahmu (loc. 16/219). 3°51’ N., 41° 13’ E. (Joubert 1960 : 20).
Oxfordian, Rahmu Shales.
Protocardia rahmuensis sp. nov., Homomya rahmuensis sp. nov.

Muguda, 24 miles S.W. of El Wak (loc. 23/217). 2° 31’ N., 40° 43’ E. (Baker &
Saggerson 1958 : 18). Oxfordian (?).
Entolium sp., Chlamys sp.

Waldire, 20 miles N.E. of Aus Mandula (loc. 23/250, 23/252). 2° 28’ N., 40° 46’ E.
(Baker & Saggerson 1958 : 18). Oxfordian (?).
Entolium corneolum (Young & Bird), Protocardia sp.

Romicho, 25 miles S.W. of El Wak. 2° 36’ N., 40° 39’ E. (loc. 23/275-277)
(Baker & Saggerson 1958 : 18). Oxfordian, beds immediately underlying Golberobe
Beds.

Cucullaea (Megacucullaea ?) sp., Mytilus (Falcimytilus) jurensis Roemer.

Golberobe hills, half-way between Wergudud and Takabba (loc. 15/227-228). 3°
23’ N., 40° 32’ E. Oxfordian, Golberobe Beds.
Lopha sp., Lopha solitaria (J. de C. Sowerby), Liostrea dubiensis (Contejean).

Korkai Hammassa, 19 miles E. of Takabba (loc. 15/443-466). 3° 22’ N., 40° 29’
E. (Saggerson & Miller 1957 : 14). Oxfordian, Golberobe Beds.

Nucula sp., Modiolus imbricatus (J. Sowerby), Modiolus (Inoperna) sowerbianus

(d’Orbigny), Gervillia saggersoni sp. nov., Meleagrinella radiata (Trautschold),

194 JURASSIC BIVALVIA AND GASTROPODA

Lopha tifoensis sp. nov., Trigonia sp., Astarte sp., Mactromya sp., Protocardia sp.,
Isocyprina ? sp., Tancredia sp. ““ A’”’, Quenstedtia sp., Cercomya sp.

Ogar Wein hills, 17 miles N.W. of Wergudud (loc. 15/535-575). 3° 24’ N., 40° 45’
E. (Saggerson & Miller 1957 : 14, 23). Oxfordian, Golberobe Beds.
Cucullaea sp., Mytilus (Falcimytilus) tufoensis sp. nov., Gervillia saggersoni sp.
nov., Meleagrinella radiata (Trautschold), Liostrea dubiensis (Contejean),
Exogyra nana (J. Sowerby), Lopha tifoensis sp. nov., Tancredia sp. “B”’,
Quenstedtia sp.

Tifo, Garri hills, 14 miles N. of Wergudud (loc. 15/380-441, 15/584-586). 3° 23’
N., 40° 56’ E. (Saggerson & Miller 1957 : 14, 42). Oxfordian, Golberobe Beds.
Modiolus imbricatus (J. Sowerby), Modiolus (Inoperna) sowerbianus (d’Orbigny),
Mytilus (Falcimytilus) tifoensis sp. nov., Mytilus (Falcimytilus) dietrichi sp. nov.,
Brachidontes (Arcomytilus) laitmairensis (de Loriol), Gervillella siliqua (Eudes-
Deslongchamps), Inoceramus sp., Placunopsis sp., Exogyra nana (J. Sowerby),
Lopha tifoensis sp. nov., Lopha sp., Trigoma sp., Protocardia sp.

Kailta, Golberobe hills, 22 miles E. of Takabba (locs. 15/599, 15/613). 3°20'7"N.,
40° 31’ E. (Saggerson & Miller 1957 : 12, 13, 42). Oxfordian, Golberobe Beds.
Mactromya quadrata (Roemer), Mactromya sp., Corbula kailtaensis sp. nov.

Asahaba, 19 miles N.N.E. of Wergudud (locs. 15/229, 230). 3° 26’ N., 40° 58’ E.
(Saggerson & Miller 1957 : 23). Oxfordian, Golberobe Beds.
Inoceramus sp., Lopha sp., Lopha tifoensis sp. nov.

Chimpa, 20 miles N.W. of Wergudud (loc. 15/223). 3° 25’ N., 40° 35’ 30” E.
(Saggerson & Miller 1957 : 14). Oxfordian, Golberobe Beds.
Meleagrinella radiata (Trautschold), Lopha tifoensis sp. nov.

Dirahara, 24 miles E.N.E. of Aus Mandula (loc. 23/280, 281). 2° 22’ N., 40°53’ E.
(Baker & Saggerson 1958 : 19, 23). Oxfordian, Golberobe Beds.
Mytilus (Falcimytilus) dietrichi sp. nov.

3 miles E. of Waldire, 24 miles N.E. of Aus Mandula (loc. 23/258). 2° 29’ N., 40°
49’ E. (Baker & Saggerson 1958 : 22). Oxfordian, Golberobe Beds.
Protocardia sp.

8 miles N.W. of Ogar Wein hills (loc. 15/38a). 3° 22’ N., 40° 39’ E. (Ayers 1952 :
23). Horizon uncertain.
Meleagrinella radiata (Trautschold).

Danissa, 8 miles N. of Wergudud (loc. 15/592). 3° 19’ N., 4° 52’ E. (Saggerson &
Miller 1957 : 42). Horizon uncertain.
Quenstedtia sp.

FROM TANGANYIKA AND KENYA 195

17 miles S. of Rahmu (loc. 16/190). 3° 40’ N., 41° 11’ E. (Joubert 1960 : 24).
Upper Oxfordian, Seir Limestones.
Meleagrinella radiata (Trautschold), Mactromya quadrata (Roemer).

7 miles N.N.E. of Raiya hills (loc. 16/16). 3°52’ N., 41° 26’ E. (Ayers 1952 : 26).
Upper Oxfordian, Seir Limestones.
Eopecten thurmanni (Brauns).

Koblollo, 15 miles $.S.W. of Rahmu (loc. 16/217). 3° 45’ N., 41° 8’ E. Upper
Oxfordian, Seir Limestones.
Procerithiidae, etc. genera indet.

Wilderri hill, rz miles $.S.W. of Rahmu (loc. 16/145). 3° 47’ N., 41° 9’ 30” E.
(Joubert 1960 : 23). Upper Oxfordian, Seir Limestones.

Grammatodon (Indogrammatodon) stockleyi Cox, Modiolus (Inoperna) sp.,
Entolium corneolum (Young & Bird), Eopecten aff. albus (Quenstedt), Chlamys
sp., Lopha gregarea (J. Sowerby), Lopha solitaria (J. de C. Sowerby), Exogyra sp.,
Amsocardia sp., Ceratomya wilderriensis sp. nov., Pseudomelamia (Rhabdoconcha)
wilderriensis sp. nov., Bourguetia saemanni (Oppel), Ampullospiva dejanira
(d’Orbigny), Harpagodes ? sp.

Low hills at Dussé, 14 miles S.E. of Rahmu (loc. 16/166). 3° 55’ N., 41° 15’ E.
(Joubert 1960 : 23). Upper Oxfordian, Seir Limestones.

Grammatodon (Indogrammatodon) irritans (Hennig), Mytilus (Falcimytilus)
qurensis Roemer, Stegoconcha gmuellert (Krenkel), Eopecten sp., Camptonectes
auritus (Schlotheim), Chlamys (Radulopecten) tnaequicostata (Young & Bird),
Lima (Plagiostoma) sp., Pseudolimea duplicata (J. de C. Sowerby), Lopha solitaria
(J. de C. Sowerby), Liostrea dubiensis (Contejean), Astarte huralensis Stefanini,
Ceratomya wilderriensis sp. nov., Pseudomelania dusseensis sp. nov., Bourguetia
saemanni (Oppel), Piettera dusseensis sp.nov., Ampullospira dejamira (d’Orbigny),
Globularia phasianelloides (d’Orbigny).

3 miles E. of Rahmu, hillside S. of road to Mandera (loc. 16/158). 3° 56’ N., 41°
17’ E. Upper Oxfordian, Seir Limestones.
Nerinella cutleri sp. nov.

5 miles W.S.W. of Rahmu (loc. 16/57). 3° 54’ N., 41° 10’ E. (Ayers 1952 : 24).
Horizon uncertain.
Entolium corneolum (Young & Bird).

6 miles N.N.E. of Raiya hills and 5 miles W.S.W. of Melka Kunha (loc. 16/17).
3° 52’ N., 41° 26’ E. Kimmeridgian, Hereri Shales.
Eopecten sp., Liostrea sp.

Hereri river crossing, 3 miles S. of Melka Kunha, 16 miles E. of Rahmu (locs. 16/

196 JURASSIC BIVALVIA AND GASTROPODA

150, 16/221). 3° 55’ N., 41° 28’ E. (Joubert 1960 : 26). Kimmeridgian, Hereri
Shales.
Grammatodon (Indogrammatodon) irritans (Hennig), Mytilus (Falcimytilus)
jurensis Roemer, Eopecten thurmanni (Brauns), Chlamys curvivarians (Dietrich),
Liostrea sp., Exogyra nana (J. Sowerby), Lucina sp., Protocardia (Tendagurium)
bannesiana (Contejean), Ceratomyopsis striata (d’Orbigny), Ceratomya excent-
vica (Roemer), Bourguetia saemanni (Oppel), Procerithiidae, Harpagodes sp.

1 mile W. of Melka Dakacha (cited as “‘ Daua valley 184 miles E. of Rahmu ’’)
(loc. 16/33). 3° 58’ N., 41° 29’ 30” E. (Ayers 1952 : 26). Upper Kimmeridgian,
Dakacha Limestones.

Trochalia depressa (Voltz).

6? miles S.W. of the Raiya hills and S.E. of Garba Raiya (loc. 16/52). 3° 44’ N.,
41° 20’ E. Upper Kimmeridgian, Dakacha Limestones.
Fimbria sp.

N. of Figfirya, northern Raiya hills (loc. 16/165). 3° 50’ N., 41° 24’ E. Upper
Kimmeridgian, Dakacha Limestones.
Liostrea sp., Protocardia sp., Quenstedtia joubertt sp. nov., Homomya sp.,
Harpagodes thirriae (Contejean), Globularia hemisphaerica (Roemer).

t mile S.W. of Melka Dakacha (cited as “‘ S. of Rahmu—Mandera road, 1g miles E.
of Rahmu ’’) ( loc. 16/31). 3° 57’ N., 41° 30’ E. (Ayers 1952 : 24). Upper Kim-
meridgian, Dakacha Limestones.

Harpagodes thirriae (Contejean).

104 miles S.W. of the Raiya hills (loc. 16/55). 3° 43’ N., 41° 14’ E. (Ayers 1952 :
24). Upper Kimmeridgian, Dakacha Limestones.
Harpagodes thirriae (Contejean).

3 miles N.E. of Melka Dakacha (loc. 16/201). 3°59’ N., 41° 33’ E. (Joubert 1960 :
28). Upper Kimmeridgian, Dakacha Limestones.
Modiolus virgulinus (Thurmann & Etallon), Modiolus (Inoperna) perplicatus
(Etallon), Lopha gregarea (J. Sowerby), Myophorella sp., Rutitrigonia stefaninii
Venzo, Mactromya quadrata (Roemer), Harpagodes thirriae (Contejean), Globu-
laria hemisphaerica (Roemer).

Melka Dakacha (loc. 16/192, 16/193). 3° 57’ N., 41° 31’ E. (Joubert 1960 : 28).
Upper Kimmeridgian, Dakacha Limestones.
Ctenostreon proboscideum (J. Sowerby), Globularia hemisphaerica (Roemer),
Trochalia depressa (Voltz), Actaeonina ? sp.

2 miles S. of Melka Dakacha (locs. 16/157, 16/209). 3°57’ N., 41° 30’ E. Upper
Kimmeridgian, Dakacha Limestones.

FROM TANGANYIKA AND KENYA 197

Nuculoma (Palaeonucula) bellozanensts sp. nov., Pteria sp., Rutitrigonia stefaninit
Venzo, Mactromya sp., Eocallista? sp., Protocardia sp., Globularia hennigi sp.
nov., Globularia phasianelloides (d’Orbigny).

W. slope, Finno, Hegalu hills (loc. 16/130). 3° 28’ N., 41° 31’ E. (Joubert 1960 :
27, pl. 11, fig. 5). Upper Kimmeridgian, Dakacha Limestones.
Camptonectes sp., Chlamys curvivarians (Dietrich), Lopha sp., Pholadomya sp.

Hegalu hills, 2 miles N. of Finno (loc. 16/211). 3° 28’ 30” N., 41° 32’ E. (Joubert
1960 : 26). Upper Kimmeridgian, Dakacha Limestones.
Pholadomya hemicardia Roemer.

5 miles S. of Galgali Gambo (loc. 16/29). 3° 53’ N., 41° 22’ E. (Ayers 1952 : 23).
Upper Kimmeridgian, Dakacha Limestones.
Lima (Plagiostoma) sublaeviuscula Krumbeck.

Hill-top x mile W.S.W. of Melka Dakacha (loc. 16/147, 16/149). 3°58’ N., 41° 30’
E. Kimmeridgian, Hereri Shales overlain by Dakacha Limestones.
Ceratomya excentrica (Roemer), Tvochalia depressa (Voltz).

Matasafara, 15 miles W. of Mandera (loc. 16/112). 3° 58’ N., 41° 39’ E. (Joubert
1960 : 32, 34). Uppermost Jurassic, Gudediye Beds.
Protocardia sp., Tancredia manderaensis sp. nov., Myopholas manderaensis sp.
nov.

W. slope of hill 4 mile E. of Hafura (loc. 16/129). 3°29’ 30” N., 41° 30’ E. Upper-
most Jurassic or basal Cretaceous, Danissa Beds.
Trigomia dainelliui Venzo.

Odda (loc. 16/207). 3° 39’ N., 41° 23’ E. (Joubert 1960 : 40). Uppermost
Jurassic or basal Cretaceous, Danissa Beds.
Trigonia dainellit Venzo.

198 JURASSIC BIVALVIA AND GASTROPODA

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INDEX TO SYSTEMATIC DESCRIPTIONS
New taxonomic names are printed in bold type.

Acesta, 62

acmon (aff.), Ataphrus, 143
Acteonina, 173

aequalis, Mactromya, 97
aequilatera, Rollieria, 29
africana, Evelissa, 157
africana, Protocardia, 1to1
africana, Tyochopsidea, 143
africanum, Eotrapezium ?, 112
Africoconulus, 141
Africomiodon, 117

aitkeni, Astarte, 87

aitkeni, Bathrotomaria, 138
aitkeni, Pseudomelania (Oonia), 151
Akera, 174

albus (aft.), Eopecten, 54
alimena, Liostrea (Catinula), 72
ambongoensis, Weyla, 59
Ampullospiva, 164

anatinus, Modiolus, 37
Anisocardia, 110

A polinter, 33

Aycomytilus, 41

arkelli, Anisocardia, 110
asaharbitensis, Corbula, 124
asaharbitensis, Palaconeilo, 25
aspasia, Pseudomelania, 147
asper, Brachidontes (Avcomytilus), 41
Astarte, 82, (sp.) 85

Ataphrus, 143

aubryi, Eopecten, 52

auritus, Camptonectes, 54
aviculoides, Gervillella, 44
ayersi, Anisocardia, 111
ayersi, Astarte, 86

ayersi, Cuspidaria, 136

Bourguetia, 152
Brachidontes, 41

brevicostata (cf.), Tvigonia, 76
briconense, Entolium, 5%
buchi, Bositra, 50

buchu, Pinna, 45
bussagensis, Cryptaulax, 160

calceifoymis, Pleuvomya, 132

camelorum, Nuculana (Praesaccella), 28

Camptonectes, 54

Catinula, 72

Cevatomya, 132
Ceratomyopsis, 106
Chartronella, 145

Chlamys, 55

Chrysostoma, 142
cingulatum, Entolium, 52
Cirrus, 146

clio, Pseudonerinea, 172
Coelastarte, 93

Coelostylina, 152
concentyica, Cevatomya, 132
conica, Pseudomelama (Oonia), 150
consobrina, Protocardia, 103
constantini, Pinna, 46
Corbula, 120

corneolum, Entolium, 51
Cossmannea, 169

costata, Lopha, 66

costata, Trigonia, 74
Cryptaulax, 160
Ctenostveon, 66

Cucullaea, 34

curta, Opisthotrigonia, 81
cuvuivarians, Chlamys, 55
Cuspidaria, 136

badiensis, Chlamys (Spondylopecten ?), 58
Bakevellia, 42
bannesiana, Protocardia (Tendagurium), 105

cutleri, Eomiodon (Africomiodon), 117 i
cutleri, Lima (Acesta), 63 }
cutleri, Lucina, 96

baron, Eomiodon, 114
basochiana, Cevatomyopsis, 106
Bathrotomaria, 138

bellozanensis, Nuculoma (Palaeonucula), 25

besairiei, Ampullospiva, 164
besairiei, Protocardia, 102
biiniensis, Lima (Plagiostoma), 59
bipartitus, Modiolus, 37

bipi, Protocardia, 103

Bositra, 50

cutleri, Nevinella, 170

Dacryomya, 26

dainellii, Trigonia, 77

dejaniva, Ampullospiva, 165
depressa, Tvochalia, 172
despecta, Lucina, 95
didimtuensis, Anisocardia, 110
didimtuensis, Astarte, 84
didimtuensis, Corbula, 120

didimtuensis, Discohelix, 137
didimtuensis, Gervillella, 43
didimtuensis, Pleuromya, 131
dietrichi, Coelastarte, 93

dietrichi, Mytilus (Falcimytilus), 40
dietrichi, Pseudomelania (Oonia), 150
dietvicht, Trigonia (Indotrigonia), 79
Dietrichiella, 14%

dilata, Osteomya, 129
dinosaurianum, Eomiodon, 116
Discohelix, 137

dodsoni, Evelissa, 158

dodsoni, Nuculana (Dacryomya), 27
dubiensis, Liostrea, 71

duplicata, Pseudolimea, 64
dusseensis, Pietteia, 162
dusseensis, Pseudomelania, 148
dwanikana, Laevitrigonia, 80

eamesi, Corbula, 123
eamesi, Mactromya, 96
echinata, Meleagrinella, 48
Eligmus, 47

elongata, Trigonia, 76
Entolium, 51

Eomiodon, 114
Eonavicula (spp. A, B), 35
Eopecten, 52

Eotrapezium, 112
episcopalis, Astarte, 88
evuca, Lopha, 69
excentrica, Cevatomya, 135
Exelissa, 157

Exogyra, 73

Falcimytilus, 39
Fimbria (spp. A, B, C), 98-100
Frenguelliella, 78

gea (aff.), Nevitoma (Neridomus), 144
Gervillella, 43

Gervillia, 45

gigas (aff.), Purpuroidea, 155
Globularia, 166

gmuellert, Stegoconcha, 47

Goniomya, 129

Grammatodon, 30

gregavea, Lopha, 68

Gryphaea, 73

Hamusina, 146
Harpagodes, 162
hemicardia, Pholadomya, 127

INDEX 211

hemisphaerica, Globularia, 166
hennigi, Cossmannea, 169

hennigi, Globularia, 167

hennigi, Gryphaea, 73

hennigi, Lopha, 71

Hippopodium, 82

hobleyi, Astarte (Leckhamptonia), 92
Homomya, 127

hortulana, Homomya, 128

huralensis, Astarte, 89

imbricatus, Modiolus, 36

Indogrammatodon, 31

Indotrigonia, 78

inequicostata, Chlamys (Radulopecten), 57
inequivalvis, Oxytoma, 47

Inoperna, 38

inornata, Homomya, 127

intricata (cf.), Lopha, 69

tvaonensis, Bakevellia, 42

wvvitans, Grammatodon (Indogrammatodon), 32

janenschi, Seebachia, 94

jouberti, Quenstedtia, 120

jumaraensis (cf.), Lima (Plagiostoma), 61
jurensis, Mytilus (Falcimytilus), 40

kailtaensis, Corbula, 125

kenti, Astarte, 85

kenti, Eotvapezium ?, 113

kenti, Tvigonia, 75

kenyana, Nuculana (Rydervia), 27
kenyanus, 4 fricoconulus, 142

kenyanus, Grvammatodon, 30
kidugalloensis, Corbula, 123
kidugalloensis, Fimbria, 98
kidugalloensis, Pronoella, 109
kidugalloensis, Pseudomelania (Oonia), 149
kidugalloensis, Tvigonia, 75
kindopeensis, A polinter, 33
kindopeensis, Lima (Acesta), 62
kindopeensis, Lopha ?, 70
kindopeensis, Musculus, 39

kindopensis, Scurriopsis (Dietrichiella), 141
kinjeleensis, Anisocardia, 112
kinjeleensis, Chiamys (Radulopecten ?), 57
kipandeensis, Cucullaea, 34
kiwawaensis, Myophorella, 80

Laevitrigonia, 80

laitmaivensis, Brachidontes (Arcomytilus), 41
Leckhamptonia, 92

lens, Thracia, 135

212

Lima, 59

Limatula, 65

Liostrea, 71

livata (cf.), Lucina, 95

livata, Pholadomya, 126
Lissochilus, 145

litevata, Goniomya, 129
Lithophaga, 36

lonjiense, Paracerithium, 159
lonjiensis, A starte, 90
lonjiensis, Psewdorhytidopilus, 139
Lopha, 66

Lucina, (sp.), 94

lurida, Astarte, 82

Mactromya, 96

madridi, Sphaeriola, 101

mandawaense, Procerithium (Rhabdo-
colpus), 156

mandawaensis, Astarte, 90

mandawaensis, Coelostylina, 153

mandawaensis, Corbula, 121

mandawaensis, Nevinella, 171

mandawaensis, Pietieia, 161

mandawaensis, Pseudolimea, 64

mandawaensis, Zygopleura, 154

manderaensis, Myopholas, 130

manderaensis, Tancredia, 119

matapwaensis, Chlamys, 56

matapwaensis, Gvammatodon (Indo-
gvammatodon), 32

mazerasensis, Civvus, 146

Meleagrinella, 48

migeodi, Limatula, 65

migeodi, Tvigonia, 77

minima, Anisocardia, 112

mitis, Pinna, 46

mitoleensis, Astarte, 92

mitoleensis, Chartronella, 145

mitoleensis, Nummocalcar, 138

Modiolus, 36

moorei, Limatula, 65

muddoensis, Lima (Plagiostoma), 60

muelleri, Astarte, 87

muelleri, Nervinella, 169

Musculus, 39

Myopholas, 130

Myophorella, 79

Mytilus, 39

namégaruensis, Lomiodon, 116
nana, Exogyra, 73
Nevidomus, 144

Neyvinella, 169
Neritoma, 144
Nuculana, 26
Nuculoma, 25
Nummocalcar, 138

oceamt (aff.), Harpagodes, 162
olimvallata, Lopha, 68

Oonia, 149

opalini (aff.), Promathildia, 168
Opisthotrigonia, 81

orientalis, Gervillella, 43
Osteomya, 129

ovalis, Pholadomya, 126
Oxytoma, 47

Palaeoneilo, 25

Palaeonucula, 25
Pavracerithium, 159
Parallelodon, 29

perplicatus, Modiolus (Inoperna), 39
phasianelloides, Globularia, 166
Pholadomya, 125

Pictavia, 167

Pietteia, 160

pindiroensis, Astarte, 86
pindiroensis, Corbula, 122
pindiroensis, Parallelodon, 29
pindiroensis, Pronocella, 108
Pinna, 45

pittieri, Cevatomya, 133
Plagiostoma, 59

Pleuromya, 131

polymorpha, Liostrea, 72
Praeconia, 94

Praesaccella, 28

proboscideum, Ctenostreon, 66

e
Procerithium, 156
Promathildia, 168

es eit |

Pronoella, 108
propebanneiana, Protocardia (Tendagurium),
106
protet, Pholadomya, 126
Protocardia, 101
Pseudolimea, 64
Pseudomelania, 147
Pseudonerinea, 172
Pseudorhytidopilus, 139
Pteria, 42
pulfreyi, Astarte, 83
Purpuroidea, 155
putealis, Pronoella, to9

Ths

le at

INDEX 213

quadrata, Mactromya, 97
quennelli, Ampullospira, 165
quennelli, Fimbria, 99
quennelli, Myophorella, 79
quenstedti, Hippopodium, 82
Quenstedtia, 119

vadiata, Meleagrinella, 48
Radulopecten, 57
rahmuensis, Homomya, 128
rahmuensis, Lima (Plagiostoma), 61
rahmuensis, Protocardia, 104
vecki, Astarte, 91

reticulata, Pholadomya, 125
Rhabdocolpus, 156
Rhabdoconcha, 151
vhomboidalis, Praeconia, 94
vollandi, Elgmus, 47
Rolhieria, 29

Rutitrigonia, 81

Ryderia, 27

saemanmi, Bourguetia, 152

sagsgersoni, Gervillia, 45

sagsgersoni, Quenstedtia, 119

schardti (cf.), Lima (Plagiostoma), 60

schencki, Protocardia, 104

Scurriopsis, 141

Seebachia, 94

siliqua, Gervillella, 44

smeei, Trigonia (Indotrigonia), 78

solitaria, Lopha, 69

somaliensis, Bositra, 50

sowerbianus, Modiolus (Inoperna), 38

sowerbyana, Astarte, 88

Sphaera, 100

Sphaeriola, 101

Spondylopecten, 58

staffi, Chrysostoma, 142

stefaniniu, Rutitrigonia, 81

Stegoconcha, 47

stockleyi, Coelostylina, 152

stockleyi, Grammatodon (Indogrammatodon),
31

stockleyi, Pietteia, 160

stvemmet, Lissochilus, 145

Striactaeonina, 173

striata, Ceratomyopsis, 107

subcorrugata, Sphaera, 100

sublaevigatus, Grammatodon, 30

sublaeviuscula, Lima (Plagiostoma), 62

subminima, Astarie, 84

suboblonga, Lithophaga, 36

subobovata, Astarte, 91

subtextoria, Chlamys, 55

suprajurensis, Protocardia, 105

supraliasica, Acteonina (Striactaeonina),
173

supraliasica, Purpuroidea, 155

Symmetrocapulus (sp.), 140

Tancredia (spp. A, B), 118
tanganyicensis, Akeva, 174
tanganyicensis, Ceratomya, 132
tanganyicensis, Corbula, 122
tanganyicensis, Eomiodon, 115
tanganyicensis, Pictavia, 167
tanganyicensis, Pieria, 42

tealet, Trigonia (Frenguelliella), 78
Tendagurium, 105

thirriae, Harpagodes, 163
thompsoni, Eotrapezium ?, 113
thompsoni, Hamusina, 146
thompsoni, Nuculana (Dacryomya), 26
Thracia, 135

thurmanm, Eopecten, 53
tifoensis, Lopha, 70

tifoensis, Mytilus (Falcimytilus), 39
tvapezicostata, Goniomya, 129
Trigonia, 74

Trochalia, 172

Trochopsidea, 143

uniformis, Pleuromya, 131
unilateralis, Astarte, 87

viceliacensis, Thracia, 135

virgatus, Grammatodon (Indogrammatodon),
31

virgulinus, Modiolus, 38

vittata, Pseudomelania, 148

weisseymeli, Astarte, 92

Weyla, 59

wilderriensis, Cevatomya, 134

wilderriensis, Pseudomelania (Rhabdo-
concha), 151

wimmisensis, Cervatomya, 133

Zygopleura, 154

PLATE 1

Fic. 1. Palaeoneilo asaharbitensis sp. nov. Bathonian [? or Callovian],
Beds. 1 mile N. of Asaharbito, N.E. Kenya. Holotype, L.83864, x 1 :
Fics. 2a, b,c. Nuculana (Dacryomya) dodsoni sp.nov. Bathonian-Callovian,

Asaharbito

p.
Bie Mayo

Limestones. Hagardulun, 25 miles N.E. of Tarbaj, N.E. Kenya. a, type series

(L.98274) on bedding plane, x 1; 0, small group of paratypes, x 2; 6,

L.98280, x 2

Dakacha Limestones. 2 miles S. of Melka Dakacha, N.E. aha Holotype,
(ep SOON Wa, S17

Fics. 4a, b, c. Nueulana (Dacryomva). home sp. nov. peer nie:
Didimtu hill, 2 miles S. of Bur Mayo, N.E. Kenya. Holotype, LL.35000: a,
6, X 2:25 2 E - : c 5 ; ; : . : :

Fics. 5a, b,c. Rollievia aequilaterva (Koch & Dunker). Upper Lias, Toarcian.
hill, 2 miles S. of Bur Mayo, N.E. Kenya. LL.35005: a, X1; 6b,¢,x3 .

Fias. 6a, b, c. Nuculana (Ryderia) kenyana sp. nov. Upper Lias, Toarcian.
hill, 2 miles S. of Bur Mayo, N.E. eee se L.35001: a, X 1;
posterior end of shell restored

Fics. 7a, b. Parallelodon Lp PR sp. nov. Bajpeen(@ ), Pindiro Shales:
liao creek, Mandawa area, Tanganyika. Holotype, LL.35086, x 1

Fics. 8a, b. Same species, horizon and locality. Paratype, LL. 35087, x I

holotype,

L.92293 :

Pp.

‘Toate
< ‘1, aeoe

Didimtu

Didimtu
6; 6, aes

Lihima-

p-
p.

Fics. 3a, b. Teal ona Geaiacenucnia| bellozanensis (de Loriol). Upper Kimmeridgian,

27

25

p. 26

p. 29

P- 27

29
29

Bull. B.M. (N.H.) Geol. Suppt. 1 PLATE 1

PLATE 2

Fics. 1a, b, c. Gvrammatodon kenyanus sp. nov. Upper Lias, Toarcian. Didimtu hill,

2 miles S. of Bur Mayo, N.E. Kenya. Holotype, LL.35006: a, x1; b,c,x2 . p.

Fics. 2a, b. Same species, horizon and locality. Paratype, LL.35007; a, x1;

,

2. : ; 5 ;: : % a F z 2 < 3 p.

Fic. 3. Gvrammatodon (Indogrammatodon) writans (Hennig). Upper Kimmeridgian,
“ Trigonia smeei’’ Bed. 4th Kipande flag, W. of Tendaguru hill, Tanganyika. L.52698,
x I

Fic. 5. Same species, horizon and locality. Left valve, LL.35090, x I :
Fics. 6a, 6. Grammatodon (Indogrammatodon) matapwaensis sp. nov. Upper Kim-
meridgian, N. of Matapwa, Pindiro area, Tanganyika. Holotype, LL.35091: a, x1;
by <3 ‘ : 3 : 5 ; 3 j : : : ‘ j Pp
Fic. 7. Gvrammatodon sublaevigatus (Zieten). Bathonian [? or Callovian], Asaharbito
Beds. 1 mile N. of Asaharbito, N.E. Kenya. L.83683, x 1 p.
Fics. 8a, b. Eonavicula sp. “A’’. Callovian [?—Lower Oxtordianil Muddo Erri
Limestones. Muddo Erri, 12 miles W. of Rahmu, N.E. Kenya. L.92046, x I : Pp
Fic. 9. Gvrammatodon (Indogrammatodon) stockleyi Cox. Upper Oxfordian, Seir

Limestones. Wilderri hill, 11 miles S.S.W. of Rahmu, N.E. Kenya. 1.92249, x I Pp.

Fics. 10a, b. Nuculana (Praesaccella) camelorum sp. nov. Toarcian or Bajocian, top
of Didimtu Beds. Camel track about 5 miles S. of Singu, N.E. Kenya. a, type series
(L.98280) on bedding ene x 1; holotype (bottom right-hand corner) and group of

paratypes, xX 2 . : : : : : 0 . : c : p-

Fic. 4. Gvrammatodon (Indogrammatodon) virgatus (J. de C. Sowerby). Callovian ?
Lonji creek, W. of Mandawa, Tanganyika. Right valve, LL.35089, x 1. : : Pp.

28

PLATE 2

Bull. B.M. (N.H.) Geol. Suppt. 1

PLATE 3

Fics. 1a, b. Cucullaea kipandeensis sp. nov. Upper Kimmeridgian, Nerinella —_
Kipande path, W. of Tendaguru, Tanganyika. Holotype, L.53146, x 1

Fic.2. Eonaviculasp.‘‘B’’. Upper Kimmeridgian, Nevinella Bed. Kindope, N. N. w.

of Tendaguru, Tanganyika. ibe LS Ligh OX a :
Fics, 3a, b. Apolinter kindopeensis sp. nov. Upper (emeneedieee, Nerinella Bed.

Kindope, N.N.W. of Tendaguru, Tanganyika. Holotype, L.56243: a, X¥ 1; 6, x2 p.

Fics. 4a, b. Same species, horizon and locality. Paratype, L.56244: a, x1;
bh Se

Fic. 6. Samespecies. Bajocian (?), Pindiro Shales Lihimaliao creek, Mandawa area,
Tanganyika. LL.35196, x 1

‘ : ; : é p.
Fic. 7. Modiolus anatinus (Smith). Bayoeen Seaca Beds. Kidugallo Station,

Central Railway, Tanganyika. LL.11554, x I

Fic. 8. Modiolus virgulinus (Thurmann & Btallon), Upper Se eae Dakacha
Limestones. 3 miles N.E. of Melka Dakacha, N.E. Kenya. L.92181, : P.

Fic. 9. Modiolus bipartitus (J. Sowerby). Upper ieee “ Trigonia sineed =

Bed. Tingutitinguti creek, Tendaguru, Tanganyika. L.52087, x1. p.

Fic. 10. Modiolus (Inoperna) sowerbianus (d’Orbigny). Upper Eas, Toarctane

Didimtu hill, 2 miles S. of Bur Mayo, N.E. Kenya. LL.35010, x 1 : ; Pp.

Fic. 11. Same species, horizon and locality. LL.35011, x 1

p.
Fic. 12. Mytilus (Falcimytilus) tifoensis sp. nov. Oxfordian, Golberobe Beds, Ogar
Wein hills, 17 miles N.W. of Wergudud, N.E. Kenya. Holotype, L.93615, x I : p-

Fic. 13. Same species, horizon and locality. Paratype, L.93617, x 1

: : p-
Fic. 14. Modiolus (Inoperna) perplicatus eae Upper Kimmeridgian. Tenda-
guru, Tanganyika. L.52153, x I : : p.

Fic. 15. Mytilus (Falcimytilus) Dielviehe sp. nov. “Upper eens “ Trigonia

smeei’’ Bed. Tendaguru, Tanganyika. Holotype, L.52187, x 1. c 3 ; p.
Fic. 16. Same species, horizon and locality. Paratype, L.52188, x 1 : ‘ p-

Fic. 5. Modiolus imbricatus (J. Sowerby). Oxfordian, Golberobe Beds. Tifo, 14 miles
N. of Wergudud, N.E. Kenya. 1.93579, x1 . : : ; : : p.

Bull. B.M. (N.H.) Geol. Suppt. 1

PLATE 4

Fics. 1a, b. Musculus kindopeensis sp. nov. Upper Kimmeridgian, Nerinella Bed.

Kindope, N.N.W. of Tendaguru, Tanganyika. Holotype, LL.11331: a, xX 1; b, xX 3 p.

Fics. 2a, b. Bvrachidontes (Arcomytilus) asper (J. Sowerby). Callovian [?—Lower
Oxfordian], Muddo Erri Limestones. Kulong, 2 miles S.W. of Muddo Erri, N.E. Kenya.

[5Q2Z007)9: 1G Es) 0s) Oe 5 A : 5 , p.

Fic. 3. Bvrachidontes peony) laitmairensis (de Loriol). itpece Kimmeridgian
N. of Matapwa, Pindiro area, Tanganyika. LL.35094, x 1°5

Fic. 4. Pteria tanganyicensis sp. nov. Upper Oxfordian. Uc river, 6 miles

W.S.W. of Kiwangwa, Bagamoyo hinterland, Tanganyika. Holotype, LL.16793, x 1 Pp.
Fics. 5a, b. Gervillella didimtuensis sp. nov. Upper Lias, Toarcian. Didimtu hill,
2 miles S. of Bur Mayo, N.E. Kenya. Holotype, LL.35012: a, exterior ; 8, interior,

showing hinge-teeth, both x I . : : De
Fic. 6. Same species, horizon aa focaiiey. Ean ne. el 3 son Bp nieein showing
hinge-teeth, x I 5 : ; p-
Fics. 7a, b. Gervillella CRA (Douvillé). iBaccan @), Pade Shales! Near site
of Mandawa well no. 1, Tanganyika. LL.35197, x1 . ; é c : : p.

Fic. 8. Same species, horizon and locality. LL.35198, x 1. : . Pp.
Fic. 9. Pinna buchi Koch & Dunker. Bajocian (?), Pindiro Shales. Near site of
Mandawa well no. 1, Tanganyika. LL.35095, x I

: ‘ 5 ‘ ‘ p-
Fic. 10. Geyvvillella siliqua (Eudes-Deslongchamps). Oxfordian, Golberobe Beds.

Tifo, 14 miles N. of Wergudud, N.E. Kenya. L. 92032, x 1

6 : c p.
Fic. 11. Gevvillia saggerysont sp. nov. Oxfordian, Golberobe Beds: Korkai Ham-
massa, 19 miles E. of Takabba, N.E. Kenya. Holotype, L.93622, x 1 . - ; Pp.

ms

Bull. B.M. (N.H.) Geol. Suppt. 1

PLATE 5

Fics. 1a, b. Meleagrinella vadiata (Trautschold). Upper Kimmeridgian, “ Tvigonia

’

smeei’’ Bed. Tapaira trail, S. of Tendaguru, Tanganyika. Right valve, L.52166:

a. Sl On eee ; a ; . A i - A 5 p. 48
Fics. 2a, b. Same species sad hose Tingutitinguti creek, Tendaguru, Tanganyika.
Rettwalvemic.52000N-ma. oo ih, Ona : ; : é : p. 48
Fics. 3a, b. Same species. Oxfordian, Galberone Bede Korkai Hammassa, 19
miles E. of Takabba, N.E. Kenya. Left valve, L.93649: a, x1; Jb, x 2a p. 48
Fics. 4a, b. Same species. Upper Kimmeridgian, “ Tvigonia smeei’’ Bed. Road to
Kindope, N. of Tendaguru, Tanganyika. Left valve, L.51136: a, X 1; b, x2. p. 48
Fic. 5. Eligmus yvollandi Douvillé. Callovian [?—Lower Oxfordian}], Muddo Erri
Limestones. 6 miles W. of Rahmu, N.E. Kenya. L.g2104, x1. P- 47
Fic. 6. Same species and horizon. 14 miles W.S.W. of Rabu, NE. Kenyan
838033 ae : : c : : : : c : : P- 47
Fic. 7. Oxytoma ue guadniais (J. Sowerby). Callovian. Chinamba, }$ mile S. of
Amboni quarries, Tanga, Tanganyika. Left valve, LL.35166, x 1 Pp. 47
Fic. 8. Stegoconcha gmuelleri (Krenkel). Upper Kimmeridgian, Nerinella Bed. N, of
Kipande north flag, Tendaguru, Tanganyika. 1.51168, x 1 : . : : P. 47

Bull. B.M. (N.H.) Geol. Suppt. 1

Fis

OF

i, A

ea

<~,

pgs:

PLATE 6

Fic. 1. Bositva buchti (Roemer). Lower Bajocian (Aalenian). Borehole at Lugoba,
Tanganyika, L.82585, x 2

Fic. 2. Bositva somaliensis (Cox). Upper Kimmeridgian, Nerinella Bed. Kindope,

N.N.W. of Tendaguru, Tanganyika. 1.51207, x 1

Fic. 3. Eopecten aubryi (Douvillé). Callovian. Manyuli stream, just W. of Nautope,

Tanganyika. Right valve, L.93550, x 1 : : : : : 4 : ;
Fic. 4. Samespecies. Upper Oxfordian. Mandawa-—Lonji creek traverse, Tanganyika.
Left valve, LL.35199, x I P ‘ i : : : ; : : : p.
Fic. 5. Entolium cingulatum (Goldfuss). Upper Jurassic. 5 miles N.E. of Tengeni,
N.E. Tanganyika. LL.35202, x I. 3 : : : : : 2 : :
Fic. 6. Entolium briconense (Cossmann). Callovian. 2} miles N. of Msaka road
junction, Bagamoyo district, Tanganyika. LL.35168, x 3 . : : . : p.
Fic. 7. Eopecten aff. albus (Quenstedt). Upper Oxfordian, Seir Limestones. Wilderri
hill, rz miles S.S.W. of Rahmu, N.E. Kenya. Left valve, L.g2247, x 1. - Pp.
Fic. 8. Eopecten thurmanni (Brauns). Upper Oxfordian, Seir Limestones. 7 miles
N.N.E. of Raiya hills. N.E. Kenya. Left valve, L.83900, x 1 : . ; : p.

PLATE 6

Bull. B.M. (N.H.) Geol. Suppt. x

PLATE 7

Fics. 1a, b. Chlamys matapwaensis sp. nov. Upper Kimmeridgian. Just N. of
Matapwa, Pindiro area, Tanganyika. Holotype, LL.35096: a, x1; b, x3 . p.

Fics. 2a, b. Same species, horizon and locality. Paratype, LL.35097: a, x1;
Dye zane : 5 : : : Pp.

FIG. 3. Chlamys iSpondplopecton. 2) badiensis Cox. " Probably Callovian, Namakambe
stream, Mandawa—Mahokondo anticline, Tale any ee WEO35 525) alee De

Fic. 4. Same species. Callovian. 4 mile N.W. of bridge over Atealnenaet river,
2 miles W. of Tanga, Tanganyika. LL.35099, x 1 : p.

Fic. 5. Chlamys (Radulopecten) inaequicostata (Young ad Bird). Upper Oxtocdaut
Seir Limestones. Dussé, 14 miles S.E. of Rahmu, N.E. Kenya. L.92228, x 1 : p.

Fics. 6a, b. Chlamys (Radulopecten ?) kinjeleensis sp. nov. Upper Kimmeridgian.
Mpilepile stream bed, near Mitole, northern Mandawa area, Tanganyika. Paratype,
ESS 008i axel OS

Fics. 7a, b. Same species. Upper Kimmeridgian, Nevinella Bed. N. of Kinjele, N.W.

of Tendaguru, Tanganyika. Holotype, L.51955: a, x1; 0b, x 3 : p.
Fic. 8. Chlamys subtextoria (Minster). Callovian. S. of Tarawanda, 11 aales S. E. of
Lugoba, Tanganyika. L.54116, x1.

Fics. 9a, b, c. Weyla ambongoensis (Thevenin). Upper Lias, Toarcian. Didimtu hill,

2 miles S. of Bur Mayo, N.E. Kenya. LL.35017: a, left valve, x 1; 3, right valve,
x I; c, ornament of ribs of right valve, x 3

Fics. toa, b. Lima (Plagiostoma) vahmuensis sp. nov. Oxfordian, Rahmu Shales.

im: miles S.W. of Rahmu, N.E. ne Holotype, L.83892: a, x 1; 6, ornament, x

61

PLATE 7

Bull. B.M. (N.H.) Geol. Suppt 1.

PLATE 8

Fic. 1. Lima (Plagiostoma) biiniensis sp. nov. Bathonian, Murri Limestones. 2 miles

W. of Melka Biini, N.E. Kenya. Holotype, L.g2174, x I. : : c : . 59
Fic. 2. Lima (Plagiostoma) muddoensis sp. nov. Callovian [?—Lower Oxfordian],
Muddo Erri Limestones. Muddo Erri, 12 miles W. of Rahmu, N.E. Kenya. Holotype,
L.g2065, XI . : : : : : : : : 3 : - : p. 60
Fic. 3. Pseudolimea mandawaensis sp. nov. Upper Oxfordian. Lihimaliao creek,
Mandawa area, Tanganyika. Holotype, LL.35100, x 1 : : : c , p. 64
Fics. 4a,b. Limatulamigeodisp.nov. Upper Kimmeridgian, Nevinella Bed. Kindope,
N.N.W. of Tendaguru, Tanganyika. Holotype, LL.11514: a, x1; 06, Xx 3 c Pp. 65
Fic. 5. Lima (Plagiostoma) sublaeviuscula Krumbeck. Upper Kimmeridgian, Dakacha
Limestones. 5 miles S. of Galgali Gambo, N.E. Kenya. L.83906, x I : : p. 62
Fic. 6. Same species, horizon and locality. 1.83905, x 1 : : é : p. 62
Fics. 7a, b. Limatula moovei sp. nov. Upper Oxfordian. Usigiwa river, 6 miles
W.S.W. of Kiwanga, Tanganyika. Holotype, LL. 16799: a, x1; 6b, xX 3 c Pp. 65
Fics. 8a, b. Pseudolimea duplicata (J. de C. Sowerby). Upper Kimmeridgian,
Nerinella Bed. Kindope, N.N.W. of Tendaguru, Tanganyika. LL.11323: a, x1;
Daas Pp. 64

Fic. 9. Lima (Acesta) cutleri sp. nov. Upper Kimmeridgian, “‘ Tvigonia smeei’’ Bed.
Tingutitinguti creek, Tendaguru, Tanganyika. Holotype, L.52033, x I 5 c p. 63
Fic. 10. Lima (Acesta) kindopeensis sp. nov. Upper Kimmeridgian, Nerinella Bed.
Kindope, N.N.W. of Tendaguru, Tanganyika. Holotype, L.56240, x 1 : ; p. 62

Bull. B.M. (N.H.) Geol. Suppt. 1

PLATE 8

PLATE 9

Fics. 1a, b,c. Lopha costata (J. de C. Sowerby). Upper Lias, Toarcian. Didimtu hill,
2 miles S. of Bur Mayo, N.E. owe ee : a, left valve ; 6, ventral view ;
c, right valve, all x I - ° ; , : :
Fics. 2a, b. Lopha eine nom. nov. Wppee Lias, Toarcian. Didimtu hill,
2 miles S. of Bur Mayo, N.E. Kenya. LL.35026: a, interior of left valve ; 6, posterior

side of left valve, attached to sheet of fibrous calcite, both Xx I. i ‘ F p.
Fic. 3. Liostvea polymorpha (Minster). Upper Oxfordian. Lihimaliao creek,
Mandawa area, Tanganyika. Left valve, LL.35102, x I : é p.
Fic. 4. Lopha solitaria (J. de C. Sowerby). Upper Oxfordian, S50 Demestones Dussé,
14 miles S.E. of Rahmu, N.E. Kenya. LL.92224, x 1 : Pp.

Fic. 5. Lopha gregavea (J. Sowerby). Upper Femeeeca Bakeacha ‘Limestones.
3 miles N.E. of Melka Dakacha, N.E. Kenya. L.92179, x I
Fics. 6a, b. Liostrea (Catinula) alimena (d’Orbigny). Callovian (Paleomen Oxfordiany
Muddo Erri Limestones. 10 miles W. of Rahmu, N.E. Kenya. 1.92137: a, left valve ;

b, posterior view, both x 1 : : : Pp.

Fics. 7a, b. Liostrea VP onpeiia: (Miinster). Uipeee Oxienran line a ‘ereels
Mandawa area, Tanganyika. LL.35103: a, left valve, with second specimen broadly
attached to it: 5b, right valve, both x 1 ‘ ; ‘ ; , ‘ :

Fics. 8a, b. Lopha cf. intvicata (Contejean). Oxfordian, Rahmu Shales. 64 miles
S.S.W. of Rahmu, N.E. ae L.83899 : a, large attachment area of left valve ;_ 6, right

valve, both x 1 : : : é : : 0 : ; 3 é Pp.

p. 66

68
72

69

p. 68

72

Pp. 72

69

PLATE 9

Bull. B.M. (N.H.) Geol. Suppt. 1

PLATE to

Fic. 1. Lopha? tifoensis sp. nov. Oxfordian, Golberobe Beds. Tifo, 14 miles N. of
Wergudud, N.E. Kenya. Paratype, L.93561, x I : : : p. 70
Fic. 2. Same species, horizon and locality. Paratype, Leese, xX I p. 70
Fic. 3. Lopha? kindopeensis sp. nov. Upper Kimmeridgian, Nerinella Bed, indane.
N.N.W. of Tendaguru, Tanganyika. -Holotype, L.54855, interior of right valve, x I p. 70
Fics. 4a, b. Same species, horizon and locality. Paratype, ae ventral part of

left valve : a, exterior; 6, interior, both x1 . : : p. 70
Fic. 5. Same species, horizon and locality. ey L. 54856, fnehion a right valve,

xi p. 70
Fic. a Lopia Paes sp. nov. (Osetia. ‘Golberobe ‘Beds. Teta, 14 Gaviles N. of

Wergudud, N.E. Kenya. Holotype, L.93574, x 1 c : : : p. 7°

Fic. 7. Same species, horizon and locality. Paratype, lgasos xele : : p. 70

PLATE 10

Bull. B.M. (N.H.) Geol. Suppt. 1

PLATE 11

Fics. 1a, b. Gryphaea hennigi Dietrich. Upper Oxfordian. Hill opposite Kingura
village, N. of Wami river, Bagamoyo hinterland, Tanganyika. LL.16848, x 1

Fics. 2a,b. Tvigonia costata Parkinson. Bajocian. Be 5 miles N.W. of Kidugallo,
Tanganyika. LL.35104: a, x1; 6, x2

Fics. 3a, b, c. Tvrigonia kidugalloensis sp. nov. SBajocue 14 ales: N.N.W. of
Kidugallo, Tanganyika. Holotype, LL.35105: a, 6, side and dorsal views, x I ;
c, side view, X 2

Fics. 4a, b,c. Tvrigonia kenti sp.nov. Bajocian. 6 miles N.W. of Kidugallo, Tangan-
yika. Holotype, LL.35107 : a, b, side and dorsal views, x 1; c, side view, X 2. p.

Fic. 5. Exogyra nana (J. Sowerby). Oxfordian, Rahmu Shales. 24 miles S.W. of

Rahmu, N.E. Kenya. L.83889, x 1. : : : : Pp.

Fics. 6a, b. Same species, horizon and ipcalitys ie 83801, xX I c
Fic. 7. Tvrigonia cf. brevicostata Kitchin. Bathonian [? or Callociem Asahanbiee
Beds. 1 mile N. of Asaharbito, N.E. Kenya. LL.11380, x 1

: p.
Fic. 8. Tvrigonia elongata J. de C. Sowerby. Callovian? 14 miles W. of Mandawa,
Tanganyika. LL.35109, x I. : : : : é : : . : Pp.

Fic. 9. Tvrigonia dainellii Venzo. Uppermost Jurassic or basal Cretaceous, Danissa
Beds. W. slope of hill $ mile E. of Hafura, N.E. Kenya. L.g2270, x1. :
Fic. 10. Tvrigonia (Frenguelliella) tealei Cox. Callovian. S. of Tarawanda, 11 miles

S.E. of Lugoba, Tanganyika. Holotype, L.54113, x 1 c p.

Fics. 11a, b. Tvrigonia migeodi sp. nov. Upper Kimmeridgian, -Nevinella Bed. I mile

N.W. of Tendaguru, Tanganyika. Holotype, L.51193: a, x1; b, x 24. : p.

Pp. 73

P- 74

Bull. B.M. (N.H.) Geol. Suppt. 1 PLATE 11

PAE 12

Fics. ta, b. Myophorella quennelli sp. nov. Kimmeridgian. W. of Mabokweni, 4
miles N.W. of Tanga, Tanganyika. Holotype, LL.11809: a, x 1; b, x 2 : p.

Fics. 2a,b. Myophorella kiwawaensis sp.nov. Upper Kimmeridgian. Kiwawa stream,
2400 yards S.E. of Mitekera survey beacon, northern Mandawa area, Tanganyika.
Holotype; —-LLE-g5nro an xX £s OF xs 5 ‘ ; : 5 5

Fics. 3a, b. Rutitrigonia stefaninit (Venzo). Upper Kimmeridgian, Dakacha Lime-

stones. 3 miles N.E. of Melka Dakacha, N.E. Kenya. L.g2180 : a, x1; b, X2 p.

Fic. 4. Opisthotrigonia curta (Aitken). Upper Kimmeridgian. Mpilepile stream,
800 yards N.E. of Mitole road junction, northern Mandawa area, Tanganyika. LL.35112,
x I 5 ; : , 3 : é : : ‘ : ; : 6 p.

Fic. 5. Laevitvigonia dwanikana sp. nov. Upper Kimmeridgian, “ Tvigonia smeei”’
Bed. Dwanika river, N.E. of Tendaguru, Tanganyika. Holotype, L.52692, x 1. p.

Fics. 6a,b. Astarte kentisp.nov. Bajocian (?), Pindiro Shales. Near site of Mandawa
well no. 1, Tanganyika. Holotype, LL.35113: a, x1; b, x2 : c p.

Fics. 7a, b. Same species, horizon and locality. Paratype, LL. aera ay Sage
SSA : 2 5)
Fic. 8. Astarte hee if Somer Weper ea Toarcicn Didimtu hile 2 miles S. of
Bur Mayo, N.E. Kenya. LL.35044, x I < . : ; 5 c é

Fics. ga, b, c. Astarte aitkeni sp. nov. Callovian. Nchia stream, 2 miles W.N.W. of
Mandawa, Tanganyika. Holotype, LL.35189: a, left valve, x 1; 5b, left valve, x 2 ;
c, dorsal view, X 2 : ; : : : : é : : :

Fics. 10a, b, c. Astarte didimtuensis sp. nov. Upper Lias, Toarcian. Didimtu hill,
2 miles S. of Bur Mayo, N.E. Kenya. Holotype, LL.35032 : a, left valve, x 1; 8, left

valve, X 2; cc, dorsal view, x 2 j : p.

Fics. 11a, b, c. Same species, horizon and locality. Paratype, ae anenae a, right
valve, X 1; 6, right valve, x 2; c, dorsal view, x 2

Fics. 12a, b. Astarte pulfreyi sp. nov. Upper Lias, Tonretian Didimaed hill, 2 miles

S. of Bur Mayo, N.E. Kenya. Holotype, LL.35027 : a, right valve ;_ b, dorsal view, both

a : : . = io

Fic. 13. Same Species, ‘henlaon aud locality. Passi. ut Paes x I
Fics. 14a, b. Astarte subminima sp. nov. Upper Lias, Toarcian. Didimtu hill, 2 2 miles
S. of Bur Mayo, N.E. Kenya. Holotype, LL.35042: a, x1; b, x3. p-
Fics. 15a, b. Astavtesp. Upper Lias, Toarcian. Didimtu hill, 2 miles S. a Bur ‘Mayer

N.E. Kenya. Li35043): a) <0 7 0) <3 ; : : c : : : p.

PLATE 12

Bull. B.M. (N.H.) Geol. Suppt. 1

PLATE 13

Fic. 1. Astarte mitoleensis sp. nov. Upper Kimmeridgian. Mpilepile stream, near
Mitole, northern Mandawa area, Tanganyika. Holotype, LL.35123, x I . Pp.

Fic. 2. Astarte weisseymeli Dietrich. Upper Kimmeridgian, “ ey emecde beds
Nitongola creek, Tendaguru, Tanganyika. L.52120, x I

Fic. 3. Same species. Upper Kimmeridgian. Mpilepile Sie near Mitole, northeast
Mandawa area, Tanganyika. LL.35204, x I

Fics. 4a, b. Astarte pindiroensis sp. nov. Bajocieat(? ys Beadira Shales. I ill: SID.

of Nkomore, Mandawa—Mahokondo area, Tanganyika. Holotype, LL.35206: a, x1;

Oe Moe : - é F ; : : : c : : : p.

Fics. 54, is Same species, horizon and locality. Paratype, LL.35207: a, x1;

i, S24 : : : : é ‘ : ; : : 2 5 p.

Fics. 6a, B Astarte sowerbyana Holdhaus. Upper Oxfordian. Lihimaliao creek,

Mandawa area, Tanganyika. LL.35120: a, left valve ; b, dorsal view, both x1 . Pp.

Fics. 7a, b. Astarte ayersi sp. nov. Bathonian [? or Callovian], Asaharbito Beds.
1 mile N. of Asaharbito, N.E. Kenya. Holotype, L.83876: a, x1; 6, x 2
Fic. 8. Astarte episcopalis de Loriol. Upper Oxfordian. Usigiwa river, 6 miles

W.S.W. of Kiwangwa, Tanganyika. LL.16839, x 1 . . : : : p.

92

92

92

86

86

88

86

88

Bull. B.M. (N.H.) Geol. Suppt. 1 BEATE 13

PLATE 14

Fic. 1. Astartelonjiensis sp.nov. Upper Kimmeridgian. Lonjicreek, W. of Mandawa,

Tanganyika. Holotype, LL.35122, x 1. c p. 90
Fic. 2. Astarte unilateralis J. de C. Sowerby. Cllaten f Lonji creel, W. of Mandawa,
Tanganyika. LL.35118, x1. c : : p. 87

Fic. 3. Same species, horizon and Tepe. Tee 45110, SATs eas : p. 87
Fic. 4. Astarte vecki Dietrich. Upper Kimmeridgian, Nerinella Bed. ecard N.W.
flag, 1 mile N.W. of Tendaguru, Tanganyika. L.51186, x 1. : . : é p. 91

Fic. 5. Same species, horizon and locality. 1.51188, x I : : p. 91

Fics. 6a, b. Astarte mandawaensis sp. nov. Upper (emnaoaidlencin,. Lente creek, W.
of Mandawa, Tanganyika. Holotype, LL.35121: a, exterior; 06, hinge-teeth (left
valve), both x 1 ; : : ; 5 , : : : ; i j p. 90

PLATE 14

Bull. B.M, (N.H.) Geol. Suppt. 1

Nn eee En

PLATE 15

Fic. 1. Astarte huvalensis Stefanini. Upper Oxfordian, Seir Limestones. Dussé, 14

miles S.E. of Rahmu, N.E. Kenya. 1.92236, group of specimens, x I . 5 Pp.

Fics. 2a, 6b. Astarte (Leckhamptonia) hobleyi sp. nov. Upper Ue Toarcian.
Didimtu hill, 2 miles S. of Bur Mayo, N.E. Kenya. Holotype, LL.35045: a, x1;

b, X16. ‘ : F : : ‘ F - 4 3 : : 5 Pp.

Fics. 3a, b. Lucina cutleri sp. nov. Upper Kimmeridgian, “‘ Trigonia smeei’’ Bed.

Lilomba creek, Tendaguru, Tanganyika. Holotype, L.52141: a, x1; 6b, X2 . Pp.

Fic. 4. Astarte subobovata Dietrich. Upper Kimmeridgian, “ Trigonia smeei’’ Bed.
Maimbwi river, S.E. of Tendaguru, Tanganyika. 1.52683, x 1

p.
Fics. 5a, b. Lucinasp. Upper Lias, Toarcian. Didimtu hill, 2 males Sr of Bur Mayo,
N.E. Kenya. LL.35047: a, side view ; 5b, dorsal view, both x 1 : p.

Fic. 6. Fimbria sp. ““A’”’. Callovian, Rukesa Shales. 13 miles W. of Renee N. =
Kenya. L.92134, x I

Fic. 7. Mactromya eae Agassiz. Callovian Palomar One eal) ‘une

2 miles S. of Muddo Erri, N.E. Kenya. 1.92072, x 1

Fics. 8a, b, c. Mactromya eamesi sp. nov. Bajocian (?), Pantie Shales: Near side of

Mandawa well no. 1, Tanganyika. Holotype, LL.35127: a, left valve, x 1; J, left
valve, x 2; c, dorsal view, x I

Fic. 9. Lucina despecta Phillips. Bajocian. 1} miles E. of Kidugallo Station,

Tanganyika. L.54090, x 1°5

Fic. 10. Fimbria sp. ‘“C’”’. Upper Kimmeridgian. Lonji creek, W. of Mandawa,
Tanganyika. LL.35126, x1 . : . ; : : : : A Pp.

Fics. 11a, b. Mactromya condi (Roemer). Upper Oxfordian, Seir Limestones.
17 miles S. of Rahmu, N.E. Kenya. 1.92218: a, left valve (imperfect) ; 56, dorsal view,
both x 1

Fic. 12. Fimbria sp. ““B’”’. Callovian [?—Lower Oxfordian], Muddo Erri Limestones.
Muddo Erri, N.E. Kenya. L.92048, x1 . : 2 é c c c : p.

89

92
96
gI
94
98

97

96

95

100

97

99

Bull. B.M. (N.H.) Geol. Suppt. 1 PLATE 15

PLATE 16

Fics. 1a, b. Fimbria kidugalloensis sp. nov. Bajocian. 1} miles E. of Kidugallo

Station, Tanganyika. Holotype, L.54103: a, x 1; 6b, ornament, x 43 . ¢ . 98
Fics. 2a, b, c. Pyrotocardia africana sp. nov. Upper Lias, Toarcian. Didimtu hill,

2 miles. S. of Bur Mayo, N.E. Kenya. Holotype, LL.35603: a, left valve, x 1; |, left

valve, x 2; cc, dorsal view, x I ‘ . a, , 5 : A ‘ . p. 101
Fic. 3. Sphaeriola madridi (d’Archiac). Bathonian [? or Callovian], Asaharbito Beds.

1 mile N. of Asaharbito, N.E. Kenya. 1.83867, associated left and right valves, x 1 p. Io1
Fic. 4. Same species, horizon and locality. L.83870, left valve, x I p. Ior
Fic. 5. Pyrotocardia consobrina (Yerquem & Jourdy). Callovian. Gaaneosoo ene

track, 4 miles from Changogo town, Tanganyika. LL.35132, x 1 p. 103
Fic. 6. Protocardia (Tendagurium) propebanneiana (Dietrich). Upper Wahine asian,

“ Trigonia smeei’’ Bed. ‘Tingutitinguti creek, Tendaguru, Tanganyika. 1.52084, x I p. 106
Fic. 7. Fimbria quennelli sp. nov. Upper Oxfordian. Usigiwa river, 6 miles W.S.W.

of Kiwangwa, Tanganyika. Holotype, LL.16841, x 1 c 3 : : Pp. 99
Fic. 8. Pyrotocardia besaiviei sp. nov. Bajocian (?), Pindiro Shales. Lihimaliao creek,

Mandawa area, Tanganyika. Holotype, LL.35128, x 1 : p. 102
Fics. ga, b. Same species. Bajocian. Mont Bovy, Mae vata N.W. Madagascar.

Paratype, L.74976: a, right valve; 6b, dorsal view, both x1 . p. 102
Fic. 10. Same species, horizon and locality. Paratype, L.74977, phe sok x I p. 102

Bull. B.M. (N.H.) Geol. Suppt. 1 PLATE 16

PLATE 17

Fic. 1. Protocardia bipi sp. nov. Bajocian (?), Pindiro Shales. Lihimaliao creek,

Mandawa area, Tanganyika. Paratype. LL.35130, x1. é : : Pp. 103
Fic. 2. Same species, horizon and locality. Paratype, LL. 351 3n, Se et c p. 103
Fics. 3a, b. Same species, horizon and ee Holotype, LL.35129: a, left valve ;

b, dorsal view, both x I : ; : : : ; : p. 103
Fics. 4a, b. Protocardia johnei sp. nov. Oxfordian, Rahmu Shales. a0 miles

S.W. of Rahmu, N.E. Kenya. Holotype, L.g2257: a, x1; b, X 2:2. : p. 104
Fics. 5a, b. Protocardia schencki Miller. Upper Kimmeridgian, “‘ Tvigonia smeei’’ Bed.

Tingutitinguti creek, Tendaguru, Tanganyika. 1.52038: a, x 1; 0b, X 2 p. 104
Fic. 6. Pvrotocardia suprajurensis (Contejean). Upper Kimmeridgian. N. of Matapwas

Pindiro area, Tanganyika. LL.35134, x I:1 5 : : ; p. 105
Fic. 7. Cevatomyopsis basochiana (Defrance). Callovian. 2 miles E. oi Maginda

Station, Tanganyika. L.67164, x To p. 106
Fics. 8a, b. Same species. Callovian pe owed Oxtordianl) Muddo Erri Thmiestanees

Kulong, 2 miles S.W. of Muddo Erri, N.E. Kenya. L.92082: a, left valve ;_ b, posterior

end, both x1. : - a : . . c : , p. 106
FIG. 9. Cevatomyopsis Shani (d’Orbigny). Kimmeridgian, Hereri Shales. Hereri

river crossing, 3 miles S. of Melka Kunha, N.E. Kenya. L.g2191, x1 . c : p. 107
Fic. 10. Pvronoella putealis sp. nov. Bajocian (?), Pindiro Shales. Lihimaliao creek,

Mandawa area, Tanganyika. Paratype, LL.35142, x 1:5 . : : : p. 109
Fic. 11. Same species, horizon and locality. Holotype, LL. S514t, 1D p. 109

Fic. 12. Pronoella pindivoensis sp. nov. SBajocian (?), Pindiro Shales. Lihimaliao

creek, Pindiro area, Tanganyika. Paratype, LL.35159 ; hinge-teeth of right valve, x I p. 108
Fic. 13. Same species and horizon. Near site of Mandawa well no. 1, maa
Paratype, LL.35138, x I . : é p. 108
Fics. 14a, b. Same species, homeo spe peda Holoaype, Te anee a, right
valve ;_ 6, dorsal view, both x 1 : : é p. 108
Fic. 15. Same species, horizon and beanie Parore. Tee 35136, aa p. 108
Fic. 16. Same species and horizon. Lihimaliao creek, Pindiro area, Tones des
Paratype, LL.35140, X I : p. 108
Fics. 17a, b. Same species and nese New site oo Mandya arelln TOT, ‘Pabantyeds
Paratype, LL.35137 : a, right valve ; 06, dorsal view, both x1 . : : : p. 108

Bull. B.M. (N.H.) Geol. Suppt. 1 PLATE 17

PLALE 18

Fics. 1a,b. Pyvonoella kidugalloensis sp.nov. Bajocian. 14 miles N.N.W. of Kidugallo,
Tanganyika. Holotype, LL.35143: a, right valve ; 0, dorsal view, both x 1
Fics. 2a, b. Eotrvapezium? thompsoni sp. nov. Upper Lias, Toarcian. Didimtu hill,
2 miles S. of Bur Mayo, N.E. cas a Holotype, LL.35061 : a, right valve ; 6, dorsal

p. 109

view, both x I : - . . : : : ‘ II3
Fic. 3. Anisocardia hinjeleensis Sp. nov. Upper Kimmeridgian. Kinjele, 5 miles W.

of Mtapaia, Tanganyika. Holotype, L.51938, x 1 : : c p. 112
Fic. 4. Anisocardia didimtuensis sp.nov. Upper Lias, ‘TPoareian! Didimtu hill, 2 miles

S. of Bur Mayo, N.E. Kenya. Holotype, LL.35056, x 1 . ; 3 5 HHO
Fics. 5a, b. Anisocardia arkelli sp.nov. Upper Lias, Moanin: Didimtu hill, 2 miles

S. of Bur Mayo, N.E. Kenya. Holotype, LL.35051: a, left valve; b, dorsal view, both x I p. 110
Fics. 6a, b. Anisocardia ayersi sp.nov. Upper Lias, Toarcian. Didimtu hill, 2 miles

S. of Bur peabe, N.E. Kenya. Holotype, LL.35057: a, right side; 6, dorsal view, both

ye ui 2 ; p. Ilr
Fics. 70, b. “Eotraperium? african Sp. nov. Upper Tee Tearcian Didimtu hill,

2 miles S. of Bur Mayo, N.E. Kenya. Holotype, LL.35058: a, right side of internal

mould ;_ 6, dorsal view, both x I : ‘ , ‘ s : ; Bp gene
Fic. 8. Anisocardia minima (J. Sowerby). Callovian, Rukesa Shales. 13 miles W. of

Rahmu, N.E. Kenya. L.92120, x1. : ; . : : : : p. 112
Fics. 9a, 6. LEotvapezium? kenti sp. noy. Bajocian. 5 miles N.W. of Kidugallo,

Tanganyika. Holotype, a left valve, LL.35144: a,exterior; 6, hinge-teeth, both x I p. 113
Fics. 10a, 6. Same species, horizon and locality. Paratype, LL.35145: a, right

valve: 6, dorsal view, both x 1 : ; ; ‘ : ; ; F : p. 113
Fic. 11. Eomiodon baront (Newton). os (?). r mile N.N.E. of Ngerengere,

Tanganyika. LL.7210, x I ; 3 : : : ‘ 114
Fics. 12a, b. Eomiodon Tepe Tp ea sp. nov. Bajocian (?). t mile N.N.E. of

Ngerengere, Ge ae cu Holotype, a right valve, LL.7215: a, exterior; 5b, interior,

both x I : , , p. 115
Fic. 13. Same species, noseod fad locality: Paratype, EL etd. x : 115
Fics. 14a, b. Eomiodon namgaruensis sp. nov. Jurassic. I mile E.S.E. of Uleka,

Marudyi—Namgaru area, Tanganyika. Holotype, LL.35146: a, right valve; 5b, dorsal

view, both x I : : 5 F : 5 5 : : : ; 116
Fics. 15a, b. Eomiodon dinosaurianum sp. nov. Upper ae ere Tendaguru,

Tanganyika. Paratype, L.53323: a, x1; b, X3. ; p. 116
Fics. 16a, b. Same species, horizon and geese Holotype, IE. Sage Ch eat S

b5*x<3 ae ‘ Z p. 116
Fic. 17. Eemitdon (Afvicomiodon) eutlove sp. nov. Upper Ranmeniceiea! “ Trigonia

smeet’’ Bed. Tingutitinguti creek, Tendaguru, Tanganyika. see L.51998, hinge-

teeth of left valve, x 2. : p. 117
Fics. 18a, b. Same species, horizon and locality. Holotype, a right wales L.51995 :

a, exterior. X 1; 6,interior, x2 . f : ; , : : p. 117

PLATE 18

Bull. B.M. (N.H.) Geol. Suppt. 1

PLATE 19

Fic. 1. Tancredia manderaensis sp. nov. Uppermost Jurassic, Gudediye Beds.
Matasafara, 15 miles W. of Mandera, N.E. Kenya. Latex ‘‘squeeze’’ from holotype,

LE.35190, X I é : : ; : : : : j : : ; p. 119
Fic. 2. Tancredia sp. ““A’’. Oxfordian, Golberobe Beds. Korkai Hammassa, 19

miles E. of Takabba, N.E. Kenya. 1.93625, x 1 : : : : : p. 118
Fic. 3. Tancredia sp. ““B’’. Oxfordian, Golberobe Beds. Ogar Wein, 17 miles N.W.

of Wergudud, N.E. Kenya. 1.93614, Se 10 : é : : ; c : 118
Fic. 4. Quenstedtia saggersont sp. nov. Oxfordian, Golberobe Beds. Ogar Wein,

17 miles N.W. of Wergudud, N.E. Kenya. Holotype, L.g3600, x 1 é p- 119
Fic. 5. Quenstedtia jouberti sp. nov. Upper Kimmeridgian, Dakacha Limestones. N.

of Figfirya, northern Raiya hills, N.E. Kenya. Holotype, L.92213, x I . p. 120
Fic. 6. Quenstedtia saggersoni sp. nov. Oxfordian, Golberobe Beds. one Ham-

massa, 19 miles E. of Takabba, N.E. Kenya. Paratype, L.93636, x I . 119
Fics. 7a, b. Corbula mandawaensis sp.nov. Bajocian (?). Depth 48-50 fect, Vendo

well no. 6, Tanganyika. Paratype, LL.35149, aright valve: a, x1; b, x4 . p. 121
Fics. 8a, b. Same species. Bajocian (?). Depth 46-48 feet, Mandawa well no. 6,

Tanganyika. Holotype, LL.35148, a left valve: a, xX 1; 0b, x 4 5 p. 121
Fics, 9a, b. Corbula tanganyicensis sp. nov. Bajocian (?). Depth Noe 4520 feet,

Mandawa well no. 7, Tanganyika. Paratype, LL.35151: a, X 1; b, X5. 122
Fic. 10. Corbula didimtuensis sp. nov. Upper Lias, Toarcian. Didimtu hill, 2 » miles

S. of Bur Mayo, N.E. Kenya. Paratype, LL.35074, X I : p. 120
Fics. 11a, b, c. Same species, horizon and locality. Holotype, Tee 45073 : a, left

valve ; 0b, right valve ; c, dorsal view, all x1. : i p. 120
Fics. 12a,b,c,d. Corbula tanganyicensis sp. nov. Bajocian Q).. Depth Aaroeeae feet,

Mandawa well no. 7, Tanganyika. Holotype, LL.35150: a, x 1; JB, left valve, x 5 ;

c, dorsal view, x 5; 4d, right valve, x 5 : , : : : . : p. 122
Fics. 13a, b. Corbula kailtaensis sp. nov. Oxfordian, Golberobe Beds. Kailta,

Golberobe hills, N.E. Kenya. Holotype, L.g2036: a, x1; b, x2 . p. 125
Fics. 14a, b, c. Corbula pindiyvoensis sp. nov. SBajocian (?). Depth T66=e7e feet,

Pindiro well no. 1, Tanganyika. Holotype, LL.35152: a, right valve, x 1; 3, right

valve, X 2; , left valve, x 2 ; p. 122
Fics. 15a, b. Same species. Bajocian @. Depth 170- 174 feet, Pindire well no. I,

Tanganyika. Paratype, LL.35153: a, left valve, x 1; 5, left valve, x 2. 122
Fic. 16. Pleuvomya didimtuensis sp. nov. Upper Lias, Toarcian. Didi hill,

2 miles S. of Bur Mayo, N.E. Kenya. Holotype, LL.35079, x 1 . p. 131
Fics. 17a, b,c. Corbula kidugalloensis sp. nov. Bajocian. 5 miles N. W. oi Kidueallon

Tanganyika. ee LL.35154: a, left valve, x 1; 5, left valve, x 2; c, dorsal

view, X 2 : é : : : : A : : : : 0 pauzs
Fics. 18a, i Corbula asaharbitensis sp. nov. Bathonian [? or Callovian], Asaharbito

Beds. 1 mile N. of Asaharbito, N.E. ee Holotype, LL.13230, aleft valve: a, X I;

OS 124
Fics. 194, - C. Copbula eamest sp. nov. Bajocian. 6 miles N. Ww. of Kidugalle;

Tanganyika. Holotype, LL.35155: a, left valve, x 1; 0b, left valve, x 2; c, dorsal

view, X 2 : : 5 : : ; ; : : : é : : p. 123
Fic. 20. Myopholas manderaensis sp. nov. Uppermost Jurassic, Gudediye Beds.

Matasafara, 15 miles W. of Mandera, N.E. Kenya. MHolotype, L. 92271, x1. : p. 130

Bull. B.M. (N.H.) Geol. Suppt. 1 PLATE 19

PLATE 20

Fic. 1. Pholadomya ovalis (J. Sowerby). Callovian [?—Lower Oxfordian], Muddo Erri
Limestones. Kulong, 2 miles S.W. of Muddo Erri, N.E. Kenya. 1.92075, x I.

Fic. 2. Pholadomya reticulata Agassiz. Upper Lias, Toarcian. Didimtu hill, 2 miles
S. of Bur Mayo, N.E. Kenya. LL.35076, x 2 é . ; : : :

Fics. 3a, b. Homomya vahmuensis sp. nov. Oxfordian, Rahmu Shales. Uacha, 6 miles
S. of Rahmu, N.E. Kenya. Holotype, L.g2260: a, right valve; 6, dorsal view, both
xe

Fic. 5. Pholadomya hemicardia Roemer. Upper Oniicn ‘Mandawa-Lonji creek

traverse, Mandawa area, Tanganyika. LL.35156, x 1 ‘ ‘ : p.

Fic. 6. Pleuromya uniformis (J. Sowerby). Upper (eamaedt tem, Kinjele, 5 miles
W. of Mtapaia, Tanganyika. 1.51934, x I

Fic. 7. Ceratomya concentrica (J. de C. Sane @allewian palenee Oxfordian],

Muddo Erri Limestones. Kulong, 2 miles S.W. of Muddo Erri, N.E. Kenya. 1.92084,
x I

Fic. 9. Pleuromya calceifoymis (Phillips). Upper Oxfordian. Mandawa—Lonji creek

traverse, Mandawa area, Tanganyika. LL.35158, x 1 é ; . p.

Fic. 10. Cevatomya excentrica (Roemer). Kimmeridgian, Hered Shales Hereri river

crossing 3, miles S. of Melka Kunha, N.E. Kenya: L.92200, x 1 : < : p-

Fic. 4. Homomya hortulana Agassiz. Upper Kimmeridgian, Nevinella Bed. N. of
Kipande, Tendaguru, Tanganyika. L.51177, x I : : : : Pp.

Fic. 8. Pholadomya livata (J. Sowerby). Callovian. 2 miles E. of Magindu Station,
Tanganyika. L.54120, x 1 - F c ; : . : - i ; p.

p. 126

p. 125

126

135

Bull. B.M. (N.H.) Geol. Suppt. 1 PLATE 20

PLATE 21

Fics. 1a, b, c. Cevatomya tanganyicensis sp. nov. Bajocian(?), Pindiro Shales.
Lihimaliao creek, Mandawa area, Tanganyika. Holotype, LL.35159: a,right valve, x I ;

b, dorsal view, X I; c, ornament, x 4 : : 5 ; ; : P : p. 132
Fic. 2. Goniomya trapezicostata (Pusch). Callovian. 4 mile N.W. of bridge over

Mkulumuzi river, 2 miles W. of Tanga, Tanganyika. LL.35157, x I. p. 129
Fic. 3. Same species. Bajocian. 14 miles E. of Kidugallo Station, Paneanaaee

L.54080, XI . - . . p. 129
Fic. 4. Cevatomya Lees (de Loriol). Galleon: Magindu Seiten Tan penapilees

LE35n00, x = : c : : ; : c 5 Pp. 133
Fic. 5. Cevatomya wi iefonts Sp. nov. Upper Oxfordian, Seir Limestones. Dussé,

14 miles S.E. of Rahmu, N.E. Kenya. Holotype, L.g2226, x1 . p. 134
Fics. 6a, b. Cuspidaria ayersi sp. nov. Bathonian [? or Callovian], “Asaliarbito Beds.

1 mile N. of Asaharbito, N.E. Kenya. Holotype, LL.13246: a, x 1; b, x 2 : p. 136
Fics. 7a, b. Same species, horizon and locality. Paratype, LL.13247: a, x1;

SS Br c : : : : : : ; : ‘ : : : p. 136
Fic. 8. Thvacia lens (Agassiz). Bajocian (?), Pindiro Shales. Lihimaliao creek,

Mandawa area, Tanganyika. LL.35161, x I : c : : : : : Pp. 135

Fic. 9. Thvracia viceliacensis (d’Orbigny). Callovian. Lonji creek, Mandawa area,
Tanganyika. LL.35162, x1 . : ; : : 5 : : - : Pp. 135

PLATE 21

Bull. B.M. (N.H.) Geol. Suppt «.

Fics. 1a, b, c, d. Discohelin didimtuensis sp. nov.

12

hill, 2 miles S. of Bur Mayo, N.E. Kenya.
x45 ©, lowertace, <x 45. d, outer face;

Fics. 2a,
stream, E. of Mitole, Tanganyika.

b, c. Nummocatcar mitoleensis sp. nov.

c, outer face, all x 1°5 . :

FIGS. 34,
14 miles W. of Mandawa, Tanganyika.

view, both

Fics. 4a,

“ Trigonia

Fics. 54,
Tingutitinguti creek, Tendaguru, Tanganyika.

Fic. 6.

b. Pseudorhytidopilus lonjiensis sp. nov. Callovian. Lonji-Runjo stream,
a, side view ; 3b, apical

x I

Holotype, GG.10312 :

ATE s2/2

Holotype, GG.10246: a, X 1;
x 4

Holotype, GG.10282 : a, upper face ;

Upper Lias, Toarcian.

b,u

Upper Kimmeridgian. Mpilepile

Didimtu
pper face,

Pp: 437

b, lower face ;

b. Scurriopsis (Dietrichiella) kindopensis (Dietrich). Upper Kimmeridgian,

smeei’’ Bed. Kindope, N.N.W. of Tendaguru, Tanganyika.
ao TO as °

b. Symmetrocapulus ? sp. Upper Kimmeridgian, “‘ Tvigonia smeei’’ Bed.
GAsogit a, oh) Oa sn

Bathvotomaria aitkeni sp. nov.

Middle-Upper Kimmeridgian.

N.

Mandawa—Namakongoro stream, about 1 mile W. of Mandawa, Tanganyika.

GG.10306 :

abapertural view, x I

p.

pe
G.48913 :
p.
: p.
Bank of
Holotype,

p.

138

139

141

140

138

Bull. B.M. (N.H.) Geol. Suppt. 1

PLATE 22

IIL ANID, 23}

Fics. 1a, b. Bathrotomaria aitkeni sp. nov. Middle-Upper Kimmeridgian. N. bank
of Mandawa—Namakongoro stream, about 1 mile W. of Mandawa, Tanganyika. Holotype,
GG.10306 : a, apertural view ; b, base, both x 1 5 C : 5 p.

Bull. B.M. (N.H.) Geol. Suppt. 1 PLATE 23

PLATE 24

Fics. 1a, b, c. Chrysostoma staffi Dietrich. Upper Kimmeridgian. Tapaira trail, S.
of Tendaguru, Tanganyika. G.48567: a, x 1; b,apertural view, x 2; c, abapertural
view, X 2 : 5 : : 5 - , 7; ‘ ‘

Fics. 2a, b. Ataphrus aff. acmon (d’ Orbigny). Bajocian. Kidugallo, Tanganyika.
Gi262045599G, x eos : é : : : 2

Fics. 3a, b. Chartronella POSS sp nov. Upper Kimmeridgian. Mpilepile
stream, about 1 mile N.E. of Mitole, Tanganyika. Holotype, GG.10313: a, apertural
view ;_ 0, abapertural view, both x I 5 A ;

Fics. 4a, b. Lissochilus stremmei Dietrich. Uppes Techasnyse earn 1} miles N.W. of

p- 142

P. 143

Pp. 145

Mandawa, Tanganyika. GG.10315: a,apertural view ; 6, abapertural view, both x 1 p. 145
Fics. 5a, b, c,d. Tvochopsidea africana sp. nov. Upper Lias, Toarcian. Didimtu hill,

2 miles S. of Bur Mayo, N.E. Kenya. Holotype, GG.10258: a, x 1; 6, apertural view,

Xx 3; c¢, abapertural view, <x 3; 4d, base, X 3. : ; , j , : Pp. 143
Fics. 6a, b. Pseudomelania (Oonia) dietrichi sp. nov. Upper Kimmeridgian. “‘ Tvigonia

smeei’’ Bed. Tingutitinguti creek, Tendaguru, Tanganyika. Holotype, G.48028 :

a, apertural view ; b, abapertural view, both x I 3 : : ‘ c p. 150
Fics. 7a, b. Neritoma (Nevidomus) aff. gea (d’Orbigny). S. of Tarawanda, 11 miles

S.E. of Lugoba, Tanganyika. G.613I0: a, X11; b, x2. p- 144
Fics. 8a, b. Cirrvus mazarvasensis sp. nov. Bajocian (2), Mazeras Gandeeonee! “Rihe!

g miles N.E. of Mazeras, Kenya. Holotype, GG.6524, ‘“‘ squeeze ’’ from natural mould :
Gears Ore 25 : : ; : : F F : ‘ : p- 146
Fics. ga, b. Hamusina thompsoni sp. nov. Upper Lias, Toarcian. Didimtu hill,

2 miles S. of Bur Mayo, N.E. Kenya. Holotype, GG.10263: a, x1; b, xX 3 : p. 146
Fic. 10. Pseudomelania aspasia (d’Orbigny). Callovian. Nchia stream, 2 miles

W.N.W. of Mandawa, Tanganyika. GG.10317, XI. ; : : F ‘ Pp. 147
Fics. 11a, b, c. Pseudomelania dusseensis sp. nov. Upper Oxfordian, Seir Limestones.

Dussé, 14 miles S.E. of Rahmu, N.E. Kenya. Holotype, G.76399; a, x1; Ob, aper-

tural view, X 3:7; ¢, abapertural view, x 3-7 . : 5 : é : p. 148
Fic. 12. Pseudomelania vittata (Phillips). Middle-Upper Kimmeridgian. 1 mile

N. of Manyuli, Tanganyika. GG.10316, x I ' : ‘ : - : ; p. 148

Bull. B.M. (N.H.) Geol. Suppt. t

PLATE 25

Fics. 1a, b, c. Pseudomelania (Oonia) aitkeni sp. nov. Middle-Upper Kimmeridgian.
Mandawa—Namakongoro stream, 1 mile W. of Mandawa, Tanganyika. Holotype,

GG.10318 : a, X 1; 6, apertural view, x 2; c, abapertural view, x 2 . p. 151
Fics. 2a, b, c. Pseudomelania (Oonia) conica (Morris & Lycett). Bathonian (). 2

miles W. of Tengeni, Tanganyika. ce a, X11; Ob, apertural view, X 2;

c, abapertural view, x 2 . - c : : : : p. 150
Fics. 3a, b. Zygopleura NETIC DES. sp. nov. Bajocian (?). Depth 58-60 feet,

Mandawa well no. 6, Tanganyika. Paratype, GG.10287: a, x1; 6b, xX 4 Pp. 154
Fics. 4a, b. Coelostylina mandawaensis sp. nov. Bajocian (?), Pindiro Shae

Lihimaliao creek, Mandawa area, ice ta Paratype, GG.10286, showing aperture :

Go Xe Ts et eS ‘ j : : j . : i p- 153
Fics. 5a,b. Same Sassi and! formation, Near site of Mandawa well no. 1, Tanganyika.

Holotype GG e283) id <a nD ee é p- 153
Fics. 6a, b. Same species, formation and ipeaiiey. Be oaae, GG. 10285 : a, >< ae

PE See ; Pp. 153
Fics. 7a, b. “Same species, (eaten zi seen. Dare GG. 160284 2 ay. Xs

bb XB : : : : : : : : j ¢ 5 c 5 p- 153
Fic. 8. Bourguetia saemanni (Oppel). Upper Oxfordian, Seir Limestones. Dussé,

13 miles S.E. of Rahmu, N.E. Kenya. G.76404, XI . p. 152
Fic. 9. Same species. Upper Oxfordian. E. margin of Makoko lain. Baeanoe

hinterland, Tanganyika. GG.2182, x I p. 152
Fic. 10. Pseudomelania (Rhabdoconcha) alder iene sp. nov. Ue Oxiondian) Seir

Limestones. Wilderri hill, 11 miles $.S.W. of Rahmu, N.E. Kenya. ged G.76414,

ei : 6 : : : : : p. 151
Fic. 11. Zygopleura mandawaensis sp. nov. Bajocian (? ), Pindiro Shales. Lihimaliao

creek, Mandawa area, Tanganyika. Holotype, GG.10465, x 3. 5 : : Pp. 154

Bull. B.M. (N.H.) Geol. Suppt. 1

PLATE 26

Fics. 1a, b. Evxelissa dodsoni sp. nov. Bathonian—Callovian, Bur Mayo Limestones.
Hagardulun, 25 miles N.E. of Tarbaj, N.E. Kenya. a, group of specimens, G.79190,
showing holotype and numerous paratypes, x 1; 06, part of same group, with holotype

near middle of left side of figure, xX 4 - : : : : p. 158
Fic. 2. Purpuroidea aff. gigas (Thurmann & Etallon). Upper Kimmeridgian. #? mile
N.W. of Mbinga, Tanganyika. GG.10328, x 08 : ; : : : : Pp. 155

Fics. 3a, b,c. Coelostylina stockleyi sp.nov. Bajocian. 2} miles N.N.W. of Kidugallo,
Tanganyika. Es GG.10281: a x1; Jb, ara view, X 3; ¢, abapertural
view, X 3 : p. 152

Fics. 4a, b, c. Pscudomelania (Gena) Ridneatioensis sp. nov. Bajociant 24 mee N.N.W.
of Kidugallo, Tanganyika. Holotype, GG.10280; a, x 1 ; b, apertural view, xX 3 ;

c, abapertural view, x 3 . c : : . : : : ¢ : c Pp. 149

Bull. B.M. (N.H.) Geol. Suppt. 1 PLATE 26

PLATE 27

Fics. 1a, b. Cvryptaulax bussagensis (Cossmann). Bathonian (?). 2 miles W. of

Tengeni, Tanganyika. GG.10464: a, x1; 6, x3. : : ; 0 ; p. 160
Fics. 2a,b. Evxelissaafricanasp.nov. Bajocian (?). Depth 58-60 feet, Mandawa well

no. 6, Tanganyika. Paratype, GG.10296: a, x1; 6b, xX 4 Pp. 157
Fics. 3a, b. Same species. Bajocian (?). Depth 52-54 fee Weeder well no. 6,

Tanganyika. Paratype, GG.10294: a, x1; b, X 4 ¢ Pp. 157
Fics. 4a, b. Same species. Bajocian (?). Depth 58-60 fect, Meera oe no. 6,

Tanganyika. Paratype, GG.10z97: a, x1; b, x4 Pp. 157
Fics. 5a, 6. Same species. Bajocian (?). Depth 58-60 feet, Wiener ene no. 6,

Tanganyika. Holotype, GG.10295: a, x1; 6b, x4 : Pp. 157
Fics. 6a, b. Paracerithium lonjiense sp. nov. Lower Kimmerideian, Wandawalonjs

creek traverse, Tanganyika. Paratype, GG.10z99: a, x1; 6, x8. Pp. 159
Fics. 7a, b. Pietteia stockleyi sp. nov. Bajocian (?). Depth 58-60 feet, Meee well

no. 6, Tanganyika. Paratype, GG.10300: a, x1; 06, x 4 : p. 160
Fics. 8a, b. Same species. Bajocian (?). Depth 60-62 feet, Meco Toe no. 6,

Tanganyika. Paratype, GG.10301: a, X1; 6b, xX 4 : : p. 160
Fics. 9a, b. Procerithium (Rhabdocolpus) mandawaense sp. nov. Enracem (?). Depth

62-64 feet, Mandawa well no. 6, Tanganyika. Paratype,GG.1oz91: a, x1; 6b, X 4 p.156
Fics. 10a, b. Same species. Bajocian (?). Depth 46-48 feet, Mandawa well no. 6,

Tanganyika. Paratype, GG.1oz92: a, x1; b, xX 4 : p. 156
Fics. 11a, b. Same species. Bajocian (?). Depth 48-50 fect, Mandawa. et no. 6,

Tanganyika. Paratype, GG.10293: a, x1; 6, x 4 : p. 156
Fics. 12a, b. Same species. Bajocian (?). Depth 46-48 eee Veaiare oy no. 6,

Tanganyika. Holotype, GG.10290: a, x1; 6, x 4 : p. 156
Fics. 13a, b. Pavacerithium lonjiense sp.nov. Lower (eaeatesa seca, Mandawallieed

creek traverse, Tanganyika. Holotype, GG.102z98: a, x1; 6b, x8. p. 159
Fics. 14a, b, c. Pietteia stockleyi sp. nov. Bajocian (?). Near site of Weamdawa well

no. 1, Tanganyika. Holotype, meee : a@, X13; 6,apertural view, x 4; c, abaper-

tural view, x 4 . : 2 ¢ : p. 160
Fic. 15. Purpuvoidea aff. eas (Pimemana & Etallon). Upper Kimmeridgian. # mile

N.W. of Mbinga, Tanganyika. GG.10328, x 0:8 5 : Pp. 155
Fics. 16a, b,c. Pietteia dusseensis sp.nov. Upper Oxtordian) Seir Limestones. Dussé,

14 miles S.E. of Rahmu, N.E. Kenya. Holotype, G.76405: a, x 1; 6b, apertural view,

X 3; c¢, abapertural view, x 3 ; : é : : : : : ; p. 162

Bull. B.M. (N.H.) Geol. Suppt. 1

i

PLATE 28

Fic. 1. Harpagodes thirriae (Contejean). Upper Kimmeridgian, Dakacha Limestones.
104 miles S.W. of Raiya hills, N.E. Kenya. Internal mould, G.70520, x 1. é Pp
Fic. 2. Same species, horizon and locality. Internal mould, G.70519, x 1.
Fic. 3. Harpagodes aff. oceani (Brongniart). Callovian. Manyuli stream, just W. of
Nautope, Tanganyika. GG.10319, x I :
Fics. 4a, b. Purpuroidea supraliasica sp. nov. Upper ee Doareient diana hill,
2 miles S. of Bur Mayo, N.E. Kenya. Holotype, GG.10264: a, apertural view (aperture
broken) ; 6, abapertural view, both x I é : : : - é
Fics. 5a, b,c. Globularia hennigi sp.nov. Upper Kimmeridgian, Dakacha Limestones.
2 miles S. of Melka Dakacha, N.E. Kenya. Holotype, G.76391 : a, abapertural view,
x 1; 0b, abapertural view, x 2; Cc, apertural view, X I é : . 5
Fias. 6a, b, c. Pictavia tanganyicensis sp. nov. Bajocian (?). Near site of Mandawa
well no. 1, Tanganyika. Holotype, GG.10302: a, x1; b, cana view, X 5;
c, abapertural view, x 5 . : c Pp
Fics. 7a, b. Same species, ened aad locality “Ease, GG, 10303 : a, <a
iy Seas ‘
Fie. 8. Ampullospare Pa (@ousieny). nee Oxtorcian! Seir ‘Limestones!
Dussé, 14 miles S.E. of Rahmu, N.E. Kenya. G.76395, x 1. :
Fic. 9. Globulavia hemisphaerica (Roemer). Upper Kammeridgian) Dae de Si
stones. N. of Figfirya, northern Raiya hills, N.E. Kenya. G.76384, x I
Fic. 10. Ampullospiva besairiei sp. nov. Bajocian. S.W. of geodetic point Antooa
Maevatanana district, N.W. Madagascar. Paratype, G.65892, x I ; Pp
Fics. 11a, b. Same species. Bajocian (?), Pindiro Shales. Near site of Mieeaceneet well
no. 1, Tanganyika. Paratype, GG.10305: a, apertural view (outer lip broken); 8,
abapertural view, both x I : : ; : : - - :
Fics. 12a, b. Same species and Bodeen ‘Lihimaliae creek, Mandawa area, Tanganyika.
Holotype, GG.10304, spire crushed in slightly : a, abapertural view ; 6, apertural view,
both xX 1 : 2 . :
Fic. 13. Same species. Bajocian. S.W. a eeodene eet Antery, Maevatananal
district, N.W. Madagascar. Paratype, G.65887, x I . : . : ' p

. 163
p. 163

p. 162

Pp. T55

p. 167

. 167
p. 167
p. 165
p. 166

. 164

p. 164

. 164

. 164

Bull. B.M. (N.H.) Geol. Suppt. x PLATE 28

K

PLATE 29

Fics. 1a,b. Globularia phasianelloides (d’Orbigny). Upper Oxfordian, Seir Limestones.
Dussé, 14 miles S.E. of Rahmu, N.E. gece it : a, apertural view ; 0b, abaper-

tural view, both x I : 2 : : : eee p. 166
Fics. 2a, b, c. Ampullospiva enn ep. nov. Callovian. Nchia stream, 2 miles

W.N.W. of Mandawa, Tanganyika. Paratype, GG.10325 : a,apertural view ; 0b, abaper-

tural view ; c, apical view, showing sutural channel, all x 1 p. 165
Fics. 3a, b,c. Same species. Kimmeridgian. Just W. of Meno eat 4 miles N.W.

of Tanga, Tanganyika. Holotype, G.g1998: a, apertural view ; 06, abapertural view ;

c, apical view, all x I 2 . . : p. 165
Fics. 4a, b, c. Acteonina (Soigomeonta al eye asien a nov. “Ups: Lias, Toarcian.

Didimtu hill, 2 miles S. of Bur Mayo, N.E. Kenya. Holotype, GG.10271: a, x1;

b, apertural view, X 2; c, abapertural view, x 2 ; é : : ‘ Pp. 173
Fics. 5a, b. Akeva tanganyicensis sp. nov. Callovian. 1 mile N.W. of Mbinga,

Tanganyika. Holotype, GG.10332 : a,apertural view ; 6, abapertural view, both x 1 p. 174
Fics. 6a, b. Pyromathildia aff. opalini (Quenstedt). Upper Lias, Toarcian. Didimtu

hill, 2 miles S. of Bur Mayo, N.E. Kenya. GG.10270: a, x1; b, x 2 c p. 168
Fic. 7. Tvochalia depressa (Voltz). Upper Kimmeridgian, Dakacha Limestone

Melka Dakacha, N.E. Kenya. G.76375: axial section (partly retouched), x I. p. 172

BUATE 29

Bull. B.M. (N.H.) Geol. Suppt. 1

PLATE 30

Fic. 1. Nerinella mandawaensis sp. nov. Middle-Upper Kimmeridgian. Mandawa-—
Namakongoro stream, about 1 mile W. of Mandawa, Tene, ee GG.10334,

Xora p. 171
Fics. 2a, be Same species, enzon and locality. Holotype, GG. 10383): a, Xs

Die Geen ee 5 p. 171
Fic. 3. Same Species, honeon and locality: Paratyec 'GGnasys. one seen in axial

section (partly retouched), x 2 . c : . : 5 : : : : p. 171
Fics. 4a, b. Nerinella cutleyi sp. nov. Upper Kimmeridgian, Nevinella Bed. Kipande

path, near Tendaguru, Tanganyika. Holotype, G.46026: a, x1; b, x2 p. 170
Fic. 5. Pseudonerinea cho (d’Orbigny). Upper Kimmeridgian. 4 mile E. of

Nangororo, Tanganyika. GG.10329, XI . p. 172
Fic. 6. Same species, horizon and locality. GG. “ae e. axial section (partly retouched),

<n : p. 172
Fia. 7. Cossmanpen hennazé (Dietrich). Wppes (oummesdicen, Tiong smeei’”” Bed.

Tributary of Maimbwi river, near Tendaguru, Tanganyika. G.48914, x I : p. 169
Fics. 8a, b. Puietteia mandawaensis sp. nov. Bajocian (?), Pindiro Shales. Near site

of Mandawa well no. 1, Tanganyika. Holotype, GG.10382: a, x1; 6b, x 4 p. 161
Fics. 9a, b, c. Africoconulus kenyanus sp. nov. Upper Lias, Toarcian. Didimtu hill,

2 miles S. of Bur Mayo, N.E. Kenya. Holotype, GG.10250: a, apertural view ; 5b, aba-

pertural view ; c, base, all x 2 . : ‘ ‘ ‘ ‘ : ; p. 142

PLATE 30

Bull. B.M. (N.H.) Geol. Suppt. 1

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SERALTIGRAPHY AND PLANKTONIC FORAMINIFERA OF TH
WPPER CRETACEOUS—LOWER TERTIARY SUCCESSION IN
fie ESNA—IDFU REGION, NILE VALLEY, EGYPT, U.A.R.

BY.

ZAGHLOUL RAGHIB EL-NAGGAR, Ph.D.

Dept. of Geology, U.C.W., Aberystwyth, now at University of Riyadh,
Saudi Arabia

23 Plates; 18 Text-figures

BULEE TRIN OF
THE BRITISH MUSEUM (NATURAL HISTORY)
GEOLOGY SUPPLEMENT 2
LONDON: 1966

THE BULLETIN OF THE BRITISH MUSEUM
(NATURAL HISTORY), instituted in 1949, ts tssued
in five series corresponding to the Departments of the
Museum, and an Historical series.

Parts will appear at irregular intervals as they
become ready. Volumes will contain about three or
four hundred pages and will not necessarily be
completed within one calendar year.

In 1965 a separate supplementary series of longer
papers was instituted, numbered serially for each
Department.

This paper is Supplement No. 2 of the Geological
(Palaeontological) series. The abbreviated titles of
periodicals cited follow those of the World List of
Scientific Periodicals.

© Trustees of the British Museum (Natural History) 1966

TRUSTEES OF
THE BRITISH MUSEUM (NATURAL HISTORY)

Issued 22nd September, 1966 Price {ro

STRATIGRAPHY AND PLANKTONIC FORAMINIFERA OF THE
PPPER CRETACEOUS-LOWER TERTIARY SUCCESSION IN
aE ESNA-IDFU REGION, NILE VALLEY, EGYPT, U.A.R.

By Z. R. EL-NAGGAR

CONTENTS
Page
I. ACKNOWLEDGEMENTS : - . : : : : - 6
II. INTRODUCTION . : : : : ; : . : 7
III. STRATIGRAPHY ; : : 0 : : : : 15
A. GENERAL Decrees j ‘ 15
B. THE UPPER Creraceous_LowEr TERTIARY IN P Beyer 5 32
C. SUMMARY OF THE SUCCESSION : : : é : 44
D. Discussion OF THE AGE : : : : : : 45
IV. PALAEONTOLOGY . ‘ P : : : : F 52
A. THE MACROFAUNA : : : : : : 52
B. THE PLANKTONIC FORAMINIEDRA : : ; : : 53
V. SysTEMATIC DESCRIPTIONS . : 66
Superfamily GLOBIGERINACEAE Ga penter Parker &

Jones : : : 66
Family GLOBOTRUNCANIDAE Brotzen : é 66
Genus Abathomphalus Bolli, Loeblich & Tappan : 66
Abathomphalus intermedia (Bolli) . : : 66
mayaroensis (Bolli) . : : 67
Genus Globotvuncana Cushman : : : , 68
Globotruncana adamsi sp. nov. : 75
aegyptiaca aegyptiaca Nakkady : 76
aegyptiaca duwi Nakkady . : 80
avabica sp. nov. : : : 81
ayca (Cushman) : : F 83
bahijae sp. nov. : : ‘ 86
conica White . : c : 87
contusa contusa (Cushman) : 90
contusa patellifoymis Gandolfi. 93
contusa scutilla Gandolfi . ‘ 95
contusa witwickae subsp. nov. . 95
cf. convexa Sandidge . : : 97
esnehensis Nakkady & Osman . 98
fareedi sp. nov. : 5 I0o
fornicata ackermannt Gandia ‘ 102
fornicata cesavensis Gandolfi : 103
fornicata foynicata Plummer : 105

fornicata globulocamerata subsp.
MOV : F : : 108
fornicata manaurensis Gandolfi_ . 109
fundiconulosa Subbotina . : IIo
gagnebini Tilev : 5 5 ie ita

cf. gagnebini Tilev . : 5 113

UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

gansseri dicavinata Pessagno : 114

ganssert gandolfii subsp. nov. : 115

gansseri ganssevt Bolli : : 117

gansservt subganssert Gandolfi é 119

havanensis Voorwijk . : : 120

leupoldi Bolli . : : : 121

lugeoni Tilev . : : : 122

mariai Gandolfi . : : 123

mariei Banner & Blow : é 124

ovientalis sp.nov. . : ; 125

vosetta pettersi Gandolfi : : 127

vosetta vosetta (Carsey) 2 ‘ 128

shavawnaensis sp. nov. : 3 130

stuarti parva Gandolfi é é 131

stuarti stuarti (de Lapparent) : 133

stuarti stuartifoymis Dalbiez 3 136

stuarti subspinosa Pessagno ; 139

subcircumnodifer Gandolfi . : 140

tricavinata colombiana Gandolfi . I4I

tvicarinata tricavinata (Quereau) . 142

ventyicosa White - 5 : 143

yousseft sp. nov. ; : ‘ 144

sp. ; : : : 145

Genus Rugoglobigerina Bronte : : : 146

Rugoglobigerina glaessnert Candotcie : : 146

loettevli (Nauss) : : : 147

macrocephala Bronnimann : 147

pennyi Bronnimann : : 148

pustulata Bronnimann ; 148

votundata Bronnimann . : 148

vugosa (Plummer) ; : 149

Genus Tvinitella Bronnimann : : ; 3 149

Trinitella scotti Bronnimann . : : : 150

Family ROTALIPORIDAE Sigal . : 150

Subfamily HEDBERGELLINAE figeniion & appae : 150

Genus Hedbergella Brénnimann & Brown . : 150

Hedbergella hessi compressifovmis (Pessapno) 5 150

hesst hesst (Pessagno) . : : 151

mattsont (Pessagno) c : : 151

monmouthensis (Olsson) : 5 I51

petaloidea (Gandolfi) : : : 152

Family GLOBIGERINIDAE Carpenter, Parker & Jones . 153
Subfamily GLOBIGERININAE sia a Parker &

Jones : : : C 153

Genus Globigerina @’ Orbigny é : é : : 153

Globigerina alanwoodi sp. nov. 5 150

aquiensis Loeblich & Tappan : 157

avabica sp.nov. . - : 157

bacuana Khalilov 4 : : 159

belli White . 3 5 159

chascanona Loeblich & Tappatt : 160

daubjergensis Bronnimann < 161

haynesi sp.nov. . : , : 165

inaequispiva Subbotina . . : 167

kozlowskii Brotzen & Pozaryska . 168

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT

mckannat White
nodosa sp. nov.
soldadoensis Pe omatencce
spivalis Bolli -
stonet Weiss
triloculinoides Diraranee
tyiloculinoides parva subsp. nov.
velascoensis Cushman
Family GLOBOROTALIIDAE Cushman
Subfamily GLOBOROTALIINAE Cushman .
Genus Globorotalia Cushman ‘ :
Globorotahia acuta Toulmin
aequa Cushman & Reaz
africana sp. nov. ;
angulata abundocamerata Bolli
angulata angulata (White)
apanthesma Loeblich & eles
berggvent sp. nov.
bollii sp. nov.
compressa (Plummer)
cf. convexa Subbotina
ehrenbergi Bolli
emilei sp. nov.
esnaensis (Le Roy)
favagisp.nov. . :
hispidicidaris Loeblich & Tappan
imitata Subbotina :
ivvovata Loeblich & Tappan
kilabiyaensis sp. nov.
loeblicht sp. nov. .
nicoli Martin
occlusa Loeblich & Tappan
perclava Loeblich & Tappan .
pseudobulloides (Plummer)
pseudomenardw Bolli
pusilla laevigata Bolli
pusilla meditervanica subsp. nov.
pusilla pusilla Bolli
quadrata (White) .
sibaiyaensis sp. nov.
tribulosa Loeblich & Tainan.
tyvinidadensis Bolli :
tvoelseni Loeblich & Tappan
uncinata cavinata sub.sp nov.
uncinata uncinata Bolli
velascoensis caucasica Glaessner
velascoensis parva Rey :
velascoensis velascoensis (Cushman).
whiter Weiss
wilcoxensis Cushman & Ponton
woodi sp. nov.
sp.
VI. SumMMaRY AND CONCLUSIONS
VII. REFERENCES
VIII. InpDEx

223
224

229
230
232
233

242
244

253

280

6 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

SYNOPSIS

The Upper Cretaceous—Lower Tertiary succession of the Esna—Idfu region is examined in
detail, and the macrofauna as well as the planktonic Foraminifera are used to interpret the
stratigraphy of the region. A total of 119 species and subspecies of planktonic Foraminifera
are described, 20 species and 6 subspecies of which are new ; 142 macrofossil species are also
identified and their ranges given. The succession is divided into distinct litho- and bio-strati-
graphical units, most of which arenew. The position of the Campanian—Maestrichtian boundary
is suggested, and the Maestrichtian is defined and zoned. Itis considered as the uppermost stage
of the Cretaceous system while the Danian is regarded as the lowermost stage of the Tertiary.
The Cretaceous—Tertiary boundary is proved to be marked by a distinct break, despite previous
emphasis on the absolute conformity of the succession. Strata of Danian age, with the typical
planktonic Foraminifera of the type section have been discovered, and have proved that pre-
viously recorded Danian strata in Egypt were incorrectly dated. The controversy over Paleocene
stratigraphy is discussed in detail, and it is recommended that the use of the existing stage names
(other than Danian) be avoided until their chronological relationships are clarified. A three-
fold division of the Paleocene on the basis of its planktonic Foraminifera is proposed, and the
position of the Paleocene—Lower Eocene boundary is suggested.

I. ACKNOWLEDGEMENTS

THE writer wishes to express his gratitude to Professor Alan Wood and to Dr. John
Haynes of the Department of Geology, U.C.W., Aberystwyth, for their guidance,
stimulating discussions and help, and for reading the manuscript. He is also
indebted to Professor M. I. Youssef of the Department of Geology, Ain Shams
University, Cairo, for his valuable discussions, encouragement, and help in the field,
and to Dr. C. G. Adams of the British Museum (Natural History), London, for making
available most of the Upper Cretaceous—Lower Tertiary foraminiferal collections of
the Museum and for his critical reading of the manuscript.

Grateful acknowledgement is made to the authorities of U.C.W., Aberystwyth,
for a grant towards the cost of preparation of the plates in this work.

Sincere thanks are also due to all those who generously forwarded their materials
and publications, helped in the field, or made available foraminiferal collections in
their charge. The author would like to mention: Dr. H. L. Abbass, Dr. F. T.
Banner, Dr. R. W. Barker, Dr. F. T. Barr, Dr. W. A. Berggren, Prof. P. J. Bermudez,
Prof. F. Bettenstaedt, Dr. E. Bieda, Dr. G. Bignot, Dr. W. H. Blow, Dr. H. M. Bolli,
Dr. P. Br6nnimann, Dr. Y. Le Calvez, Dr. A. A. Castanares, Prof. M. B. Cita, Dr. D.
K. Clark, Dr. P. Corminboeuf, Prof. M. Crusafont-Pairéd, Mr. D. Curry, Prof. J.
Cuvillier, Mr. F. Dalbiez, Dr. R. Damotte, Dr. C. W. Drooger, Dr. H. S. Edgell,
Dr. L. Feugueur, Dr. R. Gandolfi, Dr. J. J. Graham, Mr. M. Gulinck, Dr. Eo
Hamilton, Dr. W. W. Hay, Prof. H. H. Hess, Prof. I. Hessland, Dr. A. von Hille-
brandt, Dr. H. Hiltermann, Dr. J. E. van Hinte, Dr. J. Hofker, Mr. N. de B. Horni-
brook, Dr. L. Hottinger, Mr. B. Issawi, Dr. J. A. Jeletzky, Dr. G. Jenkins, Dr. J.
Klaus, Dr. I. Ktipper, Dr. M. A. Latif, Mr. J. Magné, Mr. G. Malmoustiers, Dr. P.
Marie, Prof. R. Marliére, Dr. R. K. Olsson, Dr. E. A. Pessagno, Jr., Dr. K. Pozaryska,
Dr. I. Premoli Silva, Mr. A. Rechiniac, Dr. R. W. Rex, Dr. B. Romein, Dr. J. Rosell-
Sanuy, Dr. A. Rouvillois, Prof. H. Schaub, Mrs. M. Séronie-Vivien, Prof. L. Solé-

J
:

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 7

Sabaris, Miss M. Veillon, Prof. M. Vigneaux, Dr. J. H. Van Voorthuysen, Dr. L. Weiss
and Dr. E. Witwicka.

A special word of thanks also goes to members of the technical staff of the Depart-
ment of Geology, U.C.W., Aberystwyth, for their invaluable help, and to the staff of
the various mining companies in the Esna—Idfu region and the local inhabitants for
their sincere collaboration and genuine hospitality.

Much is owed to the authorities of the Robertson Research Organization, and its
Director Dr. R. H. Cummings, for a Post-Doctoral Research Fellowship during part
of which the type sections of the Upper Cretaceous—Lower Tertiary in Western
Europe were sampled.

Finally, the author is deeply indebted to his parents who paid generously for the
various stages of this research and without whose spiritual and financial support the
work could never have been carried out.

II. INTRODUCTION

Since the later part of the nineteenth century the highly fossiliferous Upper
Cretaceous and Lower Tertiary rocks of Egypt have been the subject of numerous
stratigraphical and palaeontological studies. However, no satisfactory classification
of these rocks was established and their correlation with the type sections in Europe
proved very difficult. The difficulty has been mainly explained by the fact that the
rich macrofaunas of these rocks are strictly localized in nature, and can hardly be
correlated with the faunas of corresponding strata outside the Tethyan region. As
a result, the limits of the various stages and substages of the Upper Cretaceous and
Lower Tertiary were differently interpreted by the various authors, and were chosen,
as stated by Youssef (1957 : 45), “ rather arbitrarily, on whatever meagre evidence
the stratigrapher can collect ’’.

Recently, the rich microfossil content of these rocks has been dealt with by many
authors, but correlation with the type sections still proved very difficult, and the
stratigraphical boundaries were, once again, differently interpreted. Moreover, the
discrepancies between zonations based on macrofossils and those based on micro-
fossils led to further complications, and regrettably no attempt was made to treat
together the co-existent macro- and micro-faunas. This, added to the world-wide
problems of Cretaceous—Tertiary stratigraphy, has resulted in the complication of
the stratigraphical interpretation of this period in Egypt.

The same problems were faced in trying to analyse the stratigraphy of the Upper
Cretaceous—Lower Tertiary succession of the Esna-Idfu region. | However, the
accumulation of knowledge during the last twenty-five years has emphasized the
value of planktonic Foraminifera as guide fossils for stratigraphical zonation, and
for regional as well as world-wide correlation. In this connection, Loeblich &
Tappan (1957) : 1109) stated that ‘“‘ Because of their independence of the sea

8 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

bottom, rapid dispersal by ocean currents, and their ability to select the depth and
therefore to some extent the temperature they prefer while living, their relatively
rapid evolutionary development, and their buoyancy which allows further current
dispersal even after death of the organism, certain planktonic forms supply the best
available evidence for world-wide correlations’’. Thus, in the present study both
the macrofauna and the co-existent planktonic Foraminifera are identified and are
used to interpret the stratigraphy of the region. While the macro-fossils were found
to be restricted in their geographical distribution and only useful for local correlation,
the planktonic Foraminifera provided a sound basis for the zonation of the succession
and its correlation with the type sections and with the known planktonic foraminifer-
al zones elsewhere. Moreover, the stratigraphical ranges of the macrofossils could be
established in the light of the planktonic foraminiferal zonation, thus ending a long
controversy about their ranges.

However, despite the remarkable value of planktonic Foraminifera, the strati-
graphical and taxonomic confusion surrounding many of the species, has almost
masked their importance. The rich planktonic foraminiferal populations encount-
ered in the Upper Cretaceous—Lower Tertiary succession of the Esna—Idfu region have
helped to clear up this confusion and to establish the morphological characteristics
and the stratigraphical range of each of these species. This wealth of planktonic
Foraminifera, which probably marks the succession as the richest ever recorded,
provided an excellent opportunity for a detailed study of inter- and intraspecific
variation among large species populations and for a study of the phylogenetic
relationships between the various forms recorded. The main part of this work is
therefore devoted to a detailed study of the important members of the planktonic
Foraminifera, many of which are here described for the first time from Egypt,
North Africa and the Middle East.

LOCATION AND GEOLOGICAL SETTING OF THE ESNA-IDFU REGION. This region lies
in Upper Egypt between latitudes 24°58’00” N and 25° 20’00’N, and longitudes 32°
2000” E and 33° 05’00” E. It includes part of the Nile Valley between the towns of
Esna and Idfu, and extends eastwards and westwards into the vast deserts on either
side, covering an area of about 3,200 square kilometres (Text-fig. 1).

The region is bounded on the west and northwest by the Lower Eocoene limestone
scarp (El-Sinn) which forms the eastern edge of the famous limestone plateau of the
Western Desert. On the south and east, it is bounded by the Nubia sandstone
plateau, which extends in both directions outside the region to the basement complex,
at a distance of about 75 kms. to the east and about 100 kms. to the south.

This Nubia sandstone plateau extends into the Esna-Idfu region constituting
most of its eastern, southeastern and southern parts, dipping gently to the north-
west to be progressively overlain by the Sibatya phosphate, the Esna shale and
finally by the Thebes limestone and calcareous shale. These four main lithological
units, which are clearly recognizable in the field, together constitute the Upper
Cretaceous—Lower Tertiary succession of the Esna—Idfu region. They form the main

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 9

part of the outcrops in the region and are locally unconformably overlain by one or
more of the much younger deposits of the Pliocene, Pleistocene and Recent, which
constitute the rest of the outcrops in the region (Text-fig. 3).

LGOKPT
SCALE
Amt upnw0 40 80 tehns

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Fic. 1. Map of Egypt.

10 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

PREVIOUS WORK. The Esna—Idfu region has attracted the attention of geologists
since the earliest days of geological reconnaissance in Egypt, for the following
reasons :

1. It is the only locality in the Nile Valley where both the uppermost Cretaceous

and the basal Tertiary rocks are very well developed and well exposed.

2. It is the type area of the famous “ Esna shale’, an important group of rock
units which cover vast areas of the surface and subsurface of Egypt,
representing a relatively long period of time.

3. It contains the economically important phosphate deposits of the “ Sibaiya
formation ”’.

In spite of its geological importance, little has been published about the Esna—
Idfu region, and most publications deal mainly with the phosphate deposits. How-
ever, the stratigraphical succession at a few outcrops in the region was described in
general terms by Zittel (1883), Schweinfurth (1901, 1904), Beadnell (1905), Hume
(1911), Stromer & Weiler (1930), Cuvillier (1937a, b), Nakkady (1951b) and Youssef
(1954), but no detailed study has ever been attempted.

After examining the Upper Cretaceous—Lower Tertiary succession of the Western
Desert Oases, which he collectively related to the Danian, and divided into lower
Exogrya overwegt beds, middle greenish and ashen-grey paper-like shales, and upper
chalk with Ananchytes ovata, Zittel (1883) extended his study to the Nile Valley.
He pointed to the importance of the conspicuously developed oyster limestone bed
near Idfu which he wrongly regarded as equivalent to the “ Exogyra overwegi beds ”’
of the Kharga Oasis. He also observed the great thickness of Esna shale underlying
the Lower Eocene “ Operculina limestone ”’ on the right bank of the Nile near Esna,
and added “ If these paper-shales of Esneh correspond with those of Khargeh and
Dakhel, then the uppermost white Cretaceous limestone with Ananchytes ovata is
either wanting at Esneh, or does not contain any fossils and cannot thus be distin-
guished from the petrographically similar Eocene limestone of the Libyan stage. ”
Apparently, Zittel wrongly correlated the shales directly underlying the Lower
Eocene limestone near Esna with the lower shales underlying the snow-white chalk
of the Oases. However, as far as is known to the writer, this is the first record of the
“Esna shale ”’ in the geological literature of Egypt.

Schweinfurth (1901, 1904) also recorded these paper shales on both banks of the
Nile at Esna and El-Sharawna, and considered them to be of Eocene age following
the general belief of his time. However, neither Zittel (1883) nor Schweinfurth
(Ig01, 1904) observed any fossils in these shales.

Beadnell (1905), in a reconnaissance study designed to explain the mutual relation-
ship of the Cretaceous and Eocene systems (as understood by him), described the
succession in the desert margins on both sides of the Nile Valley between Aswan and
Esna in a series of disconnected sections. He briefly described two sections within
the Esna—Idfu region, the first was measured in the hills about one kilometre
northeast of Idfu railway station, near the village of El-Atwani, where a succession of

FF 00"
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ESNA- IDFU REGION

GEOLOGICAL MAP.

Wee Moves ed Wir fll (eens)

Greve Terreces (Vleniserre e2¢ Tin Fienicime)

ov) eed. Cenglomarsies (Mletese)

[loetr ere)

AR,

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lees et Prelle Section

Fic. 3. Esna-Idfu Region. Geological Map.

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IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT II

CRETACEQUS SYSTEM

/ Ley,
sinh ie
= BY
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ESIPASSAGE BEDS) °° 53 =
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S LOWER PALEOCENE (DANIAN)
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Shale
30m
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AMPANIAN arm Phosphete 10m frsssseset] UPPER CAMPANIAN

Nubia Sandstone
and Variegated
Shale

BEADNELL (1905) YOUSSEF (1954) PRESENT STUDY

cm 1000 O 10 20 30 40 50 ms
Vertical scale

Fic. 4. Correlation of the stratigraphical succession in G. Owaina section as interpreted
by Beadnell (1905), Youssef (1954) and by the present study.

12 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

Nubia sandstone and variegated shale, 112 metres thick, is capped by oyster lime-
stone. The second was the famous Gebel Owaina section, which was later described
in more detail by Youssef (1954).

Both Beadnell (1905) and Youssef (1954) considered the succession in Gebel
Owaina to be conformable throughout. Beadnell stated that “..... the first fact
that impresses the observer is the absolute conformity of the succession throughout.’’,
and Youssef also stated “‘ The sequence is apparently conformable throughout.”

The descriptions of the succession and the interpretations of the stratigraphy
given by Beadnell (1905) and by Youssef (1954) are summarized and compared with
those of the present study in Text-fig. 4.

Hume (1911) briefly described the succession in the shallow valleys to the east of
El-Kilabiya village. He considered the strata between the Campanian oyster lime-
stone and the Lower Eocene nummulitic limestone as belonging to the Danian,
which he regarded as the uppermost Cretaceous.

Stromer & Weiler (1930) described the vertebrate remains of both the Nubia
formation and the overlying phosphate beds of the Mahamid district, and the
geology of the same district was briefly dealt with by Nakkady (1951b). In agree-
ment with previous works, these authors confirmed the Campanian age of both the
Nubia and the phosphate formations.

Cuvillier (1937a,b) in a very generalized discussion, assigned the shale and the
intervening chalk succession of both Gebel El-Kilabiya and Gebel El-Sharawna to
what he collectively described as Maestrichtian—Danian.

Youssef (1954) described the succession in the Gebel Owaina section, using the
Foraminifera as well as the macrofossils to interpret the stratigraphy. Although he
overlooked the distinct break between the Cretaceous and Tertiary rocks and
considered the Danian (within which he included most of the Paleocene) as the
youngest stage of the Cretaceous system, his study is the only serious attempt to
tackle the stratigraphical problems of this section. Youssef did not deal with the
Nubia sandstone and the phosphate beds which constitute the lowest part of the
succession, but simply noted that Beadnell (1905) assigned a Campanian age to the
latter beds. However, he referred the shale section directly overlying the phosphate
beds to the Maestrichtian, and arbitrarily considered the Maestrichtian—Danian
boundary to cut through the middle part of his 97 metres thick shale succession
overlying the Pecten mayereymari marl (see Text-fig. 4). He assigned the upper
half of this shale section and the overlying chalk bed to the Danian, and referred the
upper shale section to the Paleocene and the overlying siliceous limestones to the
Lower Eocene, although he added that a closer study may prove that these lime-
stones are still of Paleocene age.

Youssef (1954), following Cuvillier (1934) and Nakkady (1951a) suggested that the
term Esna shale, as a formation name, should be abandoned to avoid the different
age significances adhering to the term through long use. However, he added that the

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 13

“Esna shales ’’, as a facies name, should be retained and thus proposed the term

eeesnarshale facies’... ... as an expression of certain lithological and palaeonto-
logical characters of a part of the stratigraphic column in certain parts of Egypt.”

In all these studies the succession was only briefly described, and the limits of the
various stages and substages were vaguely defined. As a result the succession was
wrongly considered to be conformable throughout, and correlation with the type
sections or the known other sections outside the Tethyan region could not be achieved.
Moreover, no palaeontological study was ever attempted and no geological map of the
region was published, except for a very small part in the neighbourhood of El-Kab
which was mapped by Schweinfurth (1904). The latter has only schematically
shown the distribution of what he described as Campanian, scattered, rolled
Eocene pebbles, and Pleistocene and Recent. A part of this map was used by
Nakkady (1951a) where the same mapping units were followed.

In a recent geological study of the Esna—Idfu region, the present writer mapped
the area in detail. This mapping which has resulted in the classification of the
surface rocks into distinct litho- and bio-stratigraphical units, has also proved for the
first time, the existence of a distinct break between the Maestrichtian and the over-

lying Paleocene rocks. In spite of repeated emphasis on the absolute conformity of
the succession by previous workers, a conglomerate with reworked Upper Cretaceous
macrofossils was clearly observed in the field and a distinct faunal break was proved
| by the study of the macrofauna and the planktonic Foraminifera. The existence of
such a stratigraphical break in a region where continuous deposition and absolute
| conformity between the Cretaceous and Tertiary systems has been unquestionably
accepted, throws a new light on the geological history of Egypt during late Creta-
ceous and early Tertiary time. Moreover, comparison with various Upper Creta-
ceous—Lower Tertiary sections in Egypt has clearly indicated the existence of
stratigraphical breaks of varying magnitudes in areas where the succession was
described as conformable throughout.

The detailed geology of the region is discussed elsewhere (El-Naggar, im manu.)
and the main objects of the present investigation can be summarized as follows :

I. Stratigraphical analysis of the Upper Cretaceous—Lower Tertiary succession
of the Esna—Idfu region on the basis of its lithology and macrofossil content,
and correlation with corresponding sections in other parts of Egypt.

2. Analysis of the succession on the basis of its planktonic Foraminifera ;
correlation with the planktonic foraminiferal zones in other parts of the
world, and the establishment of the ranges of the recorded macrofossil
species in the light of the planktonic foraminiferal zonation.

3. Detailed systematic study of the planktonic Foraminifera.

METHODS OF INVESTIGATION. The Esna—Idfu region was geologically mapped,
using topographical sheets, scale I : 100,000 and aerial photographs, scale I : 40,000.
As stated above, the detailed geology of the region and the maps are discussed else-
where and only small scale reproductions of the maps are presented here (Text-figs. 2,

4 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

3) to show the distribution of the various rock units and the location of the sections
studied.

Every possible outcrop in the region was carefully examined and sampled ; fossils
were collected, and lateral as well as vertical variation in the different rock units was
considered. The succession was first divided, on the basis of its lithology, into five
formations and eight members (Text-fig. 5) which are clearly distinguished in the
field. It was then zoned on the basis of the macrofossils in its various units, and was
correlated with similar successions in other parts of Egypt. However, because of the
restricted geographical distribution of most of these macrofossils, correlation with
the type sections or the other known sections outside the Tethyan region could not be
achieved, and thus the limits of the various stages and substages could not be
definitely decided.

To overcome this difficulty, eight main sections, representing the succession in
different parts of the region (Text-fig. 7) were chosen for the detailed study of
planktonic Foraminifera. Several other sections were also examined, but being
mainly composed of the Nubia sandstone and/or the Sibaiya phosphate formations,
they were either devoid of Foraminifera, or yielded only very rare, indeterminable
specimens and are not discussed here.

The sections were measured and sampled in detail, using a tape, a Brunton compass
and an “‘ Abney-level’’. Samples were collected every three metres and every
metre or even fraction of a metre when necessary (Text-fig. 7).

About three hundred samples (100 gms. of each) were processed for foraminiferal
analysis using standard techniques which differed according to the nature of the
rocks. In each case, the residue was dried and passed through a series of sieves
(30, 60, 120 and 200 mesh).

All the planktonic Foraminifera in each fraction were picked out and examined,
counts were made and range charts were constructed. However, as the ranges were
found to conform well in all the studied sections, it was not found necessary to present
a chart for each section. The ranges on the general charts, here included, represent
the ranges in the corresponding parts of each of the studied sections.

Ninety five species and twenty four subspecies of planktonic Foraminifera are
identified, twenty species and six subspecies of which are new. All members of the
genera Globotruncana, Globigerina and Globorotalia are described and figured, except
for a few rare forms which are not figured. All figures are camera lucida drawings
by the author. Members of the genera Abathomphalus, Rugoglobigerina, Trinitella
and Hedbergella are only listed and will be figured and described in a future publi-
cation.

Comparison with type material was carried out wherever possible, and in such
cases it is noted in the remarks on each species.

All types and figured specimens are in the British Museum (Natural History),
London ; a duplicate collection is deposited in the Department of Geology, U.C.W.,
Aberystwyth.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 15

III. STRATIGRAPHY
A. GENERAL DISCUSSION

The controversy about Upper Cretaceous—Lower Tertiary stratigraphy has-
probably been one of the most prolonged in the history of geological literature. The
loose definition of the various stages and substages and their varied interpretation
by different authors has always made it difficult to establish the true stratigraphical
relationship between one stage and another, and has led to great confusion.

A detailed study of the type sections of these stages and substages, with a critical
analysis of previous literature, is very badly needed to clear up this confusion.
However, such detail is beyond the scope of the present work, although the author
has sampled these sections, and the samples as well as the previous literature are
now.being analysed. Nevertheless, it was found necessary to summarise the strati-
graphical problems of the various stages and substages dealt with here, and the
classification adopted in the present study, before proceeding to discuss the succession
in the Esna—Idfu region.

The present study is mainly concerned with the period from the Upper Campanian
to the Lower Eocene, and the main points of disagreement about the stratigraphy of
this period can be summarized as follows :

1. Where should the Campanian—Maestrichtian boundary be drawn, and what is

the position of the Maestrichtian in Upper Cretaceous stratigraphy?

2. Does the Danian represent the uppermost Cretaceous or the basal Tertiary,

and what is the nature of the Mesozoic—Cainozoic boundary?

3. What is the stratigraphical position of the Paleocene, and the relationship

between its various stages and substages?

4. Where should the Paleocene—Lower Eocene boundary be drawn?

THE CAMPANIAN—MAESTRICHTIAN BOUNDARY AND THE POSITION OF THE
MAESTRICHTIAN IN UPPER CRETACEOUS STRATIGRAPHY

In 1842, d’Orbigny introduced the term “ Senonian ”’ in Upper Cretaceous strati-
graphy to define the geological interval represented by the white chalk around
“Sens ’”’, southeast of Paris. However, he did not designate a particular type
section for his Senonian, but simply stated that ‘‘Sens”’ is situated amidst this
white chalk which is characterized by its fauna.

Four years later, Desor (1846) introduced the term ‘‘ Danian’ to describe the
succession of the Cerithiwm, bryozoan, coralline and coccolithic limestones which
disconformably overlie the Senonian white chalk of Denmark and which he had
previously observed at ‘“‘ Laversines”’ and “‘ Vigny”’ in the Paris Basin. He
considered the Danian as the youngest stage of the Cretaceou system, and the same
concept was automatically followed by most stratigraphers.

In 1849, Dumont introduced the term “‘ Maestrichtian ’’ to describe the “‘ calcaire
grossier ”’ exploited at the quarries of Maestricht! in southern Limbourg, Holland,

1 Dumont’s original French spelling of Maestricht is used throughout this work.

16 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

,

which he wrongly equated with the “ Tuffeau de Ciply’’ and the limestone of
“ Folx-les-Caves ’’ in Belgium, and correlated with the “ calcaire pisolithique ”’ of

the Paris Basin, which Desor had previously correlated with his Danian.

A year later, d’Orbigny (1850) described the characteristic fauna of his Senonian,
including the Maestrichtian of Dumont as the upper part of this stage.

D’Orbigny (1852) recognised seven stages in the Cretaceous system, all of which
except the first and last, were established by him. They are, from the base upwards :
Neocomian, Aptian, Albian, Cenomanian, Turonian, Senonian, and Danian. These
stages have since been generally accepted by most stratigraphers, in spite of disagree-
ments and controversies regarding their limits.

While d’Orbigny regarded the Senonian as comprising the succession of strata
between the uppermost Turonian and the basal Danian, Hébert (1875) excluded the
Maestrichtian of Dumont, considering it to range into the Danian, and Haug (1908—
11) included the Danian of Desor within the Senonian.

Coquand (1857) divided the Senonian into four substages which he named from
the base upwards : Coniacian, Santonian, Campanian and Dordonian. However,
de Grossouvre (1897, Ig01) considered the Dordonian to be a junior synonym of the
Maestrichtian of Dumont (1849) and included the latter within the Campanian as its
uppermost part. He also subdivided the Campanian (in his sense), on the basis
of ammonities, into four successive zones which he named from the base upwards :
the Placenticeras bidorsatum Zone, the Taxanites delawarense Zone, the Hoplito-
placenticeras vari Zone and the Pachydiscus neubergicus Zone. On the other hand,
Arnaud (1897) showed that the ammonite fauna of the type Dordonian (the Pachy-
discus neubergicus Zone of de Grossouvre) is quite distinct from that of the Campan-
ian, and should be considered separately. However, in agreement with de Gross-
ouvre, he regarded the Dordonian as a junior synonym of the Maestrichtian thus
considering the Senonian stage to include the four substages : Coniacian, Santonian,
Campanian and Maestrichtian. This classification was followed by most authors,
although the limits between the various substages, especially those of the Campanian
and the Maestrichtian, have been largely disputed and mostly unsettled. This has
been mainly explained by the fact that the original definition of the Maestrichtian
by Dumont (1849) was rather vague and ambiguous and thus its lower limit has been
always chosen arbitrarily by the different authors. Again, while in fact no definite
Maestrichtian deposits have yet been described in the Paris Basin, Dumont wrongly
correlated the Maestricht chalk tuff with the so-called “ pisolitic limestone”’ of
Laversines and Vigny, which further complicated the problem. Moreover, de
Grossouvre (1897, IgoI) on the one hand, included the Maestrichtian within the
Campanian as its uppermost part, and Haug (1908, IgII) on the other, extended the
Maestrichtian downwards in the succession to include the uppermost part of the
Campanian at its base. As a result, Haug attached the chalk with Belemmitella
mucronata to the Maestrichtian, and thus considered the Meudon Chalk of the Paris
Basin, and the “chalk of d’Obourg’’, the “‘ Nouvelles chalk ’’, the “ Spiennes

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 17

chalk’ and the “ phosphatic chalk of Ciply’”’, in Belgium to be of Maestrichtian
age. To justify this, he subdivided the Upper Campanian Hoplitoplacenticeras vari
Zone of de Grossouvre into a lower zone with Hoplitoplacenticeras vari which he
considered to be of Upper Campanian age, and an upper zone with Bostrychoceras
polyplocum which he attached to the Maestrichtian. Therefore, he considered the
Maestrichtian (in his sense) as comprising two ammonite zones, an upper with
Pachydiscus neubergicus (=Maestrichtian) and a lower with Bostrychoceras poly-
plocum (=uppermost Campanian), although the latter species has never been
recorded in the type Maestrichtian or in its junior synonym, the Dordonian.

This downward extension of the Maestrichtian as suggested by Haug was followed
by Spath (1926), Laffitte (1934, 1939), Marie (1937, 1943), Gignoux (1943, 1950),
Muller & Schenck (1943) and Mikhailov (1947, 1948) as well as many other authors,
and has confused the position of the Campanian—Maestrichtian boundary.

On the other hand, Cornet & Briart (1874), followed by Umbgrove (1925, 1926),
Withers (1935), Bubnoff (1935), Van der Heide (1954), etc. restricted the Maestrich-
tian stage to the Maestricht tuff and its equivalents only, but this did not solve the
problem of the Campanian—Maestrichtian boundary. To overcome this difficulty,
Leriche (1927, 1929), quite justifiably, included in the Maestrichtian, all Upper
Cretaceous strata in the type area of Dumont, which are older than the Danian of
Desor (1846) and younger than the Senonian of d’Orbigny (1842) and the Campanian
of Coquand (1857). This concept, which clearly signifies that no equivalents of the
Maestrichtian occur in the type Senonian of d’Orbigny, created a tendency among
various authors to regard the Maestrichtian separately from the Senonian. This has
been substantiated by the fact that Schijfsma (1946) considered the Foraminifera of
the Belemmitella mucronata chalk of the Paris Basin, which represents the upper part
of d’Orbigny’s Senonian, to be of Middle and Upper Campanian age, and thus he
denied the presence of Maestrichtian in the Paris Basin, although Marie (1943)
considered the Meudon Chalk to be of Maestrichtian age.

Visser (1951) studied the Foraminifera of the type “‘ Maestricht tuffaceous chalk ”’,
reviewing previous studies and discussing the various usages of the term Maestricht-
ian. She mentioned that while Gignoux (1936-1950), followed by most French
stratigraphers, had equated the Maestrichtian with the Belemnitella mucronata Zone,
Muller & Schenck (1943) equated it with the B. lanceolata Zone, restricting the
mucronata Zone to the Campanian, and Brotzen (1936) considered the mucronata
Zone to be younger than the Maestrichtian. On the other hand Schijfsma (1946)
considered the B. mucronata Zone to represent both the Upper Campanian and the
Maestrichtian, while he considered the Middle Campanian to be represented by a
particular horizon in which both B. mucronata and Goniatheutis quadrata occur, and
the Lower Campanian to be represented by the G. quadrata Zone only. She also
mentioned that while in Belgium and Holland the term Maestrichtian s.s. is generally
used to describe both the Maestricht tuffaceous chalk and the Kunrade chalk, the
term Maestrichtian s./. (or the Maestrichtian as understood by French authors)
includes the underlying Gulpen chalk as well. Following Schijfsma (1946), she

18 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

considered the oldest Cretaceous outcrops in Limburg (the Heervian and the Aachen
sands) as belonging to the Middle Campanian. However, as her study was mainly
concerned with the Maestricht tuffaceous chalk, she could not precisely define the
lower boundary of the Maestrichtian.

Jeletsky (1951), following Leriche (1927, 1929) and Schijfsma (1946) considered
the Maestrichtian as “..... an independent stage younger than and equal in rank
to the Senonian stage....’’, while he considered the Campanian as the upper
substage of the Senonian. He stated that “ The latest research of Abrard (1931
pp. 24-5 ; 1948 pp. 231, 233, 279-280) has, indeed, shown that at the type locality
of the Campanian stage in southwest France, near Champagne, the beds with
Bostrychoceras polyplocum (Roemer)..... , were originally included in upper
Campanian and not in lowermost Dordonian (an invalid synonym of Maestrichtian) ”’.

Jeletzky’s proposition was questioned by Van der Heide (1954) because it meant a
slight change of the Maestrichtian as originally defined by Dumont (1849). However,
as previously mentioned by Romein (1961, 7¢ Colloque European de Micropaléontol-
ogie, Pays-Bas et Belgique, Guide d’Excursions, B. Upper Cretaceous, Limbourg :
1-3) the confusion and ambiguity of Dumont’s definition of the term Maestrichtian,
led to the fact that the term has evolved through the times, independently from the
original definition of the type locality. The succession in the type area which is
known under the names of the tuffaceous limestone of Maestricht (Ma—Md) and the
Gulpen chalk (Cr,) is generally considered to be of Upper Maestrichtian age (Meyer
1959 and Voigt 1960). However, Romein (1962) extended the Maestrichtian in its
type area downwards to include most of the Gulpen chalk [Cr,, (in part)—Cr,], and
the Maestricht chalk (Ma—Me) which he partly equated with the Kunrade chalk.

In 1959, the “‘ Congrés des Sociétés Savantes de Paris et des Départements”’ held at
Dijon, discussed the stratigraphical and palaeontological problems of the Upper
Cretaceous in France “ Colloque sur le Crétacé Supérieur Francais’’. In spite of
numerous disagreements, the congress came to the following conclusions :

1. The Bostrychoceras polyplocum Zone which has always been assigned to the
Lower Maestrichtian, is considered to be of Upper Campanian age.

2. The Maestrichtian is limited to the zone of Pachydiscus neubergicus.

3. Although strictly speaking the Maestrichtian should be excluded from the
Senonian, it is generally admitted in France that the Upper Senonian
includes both the Campanain and the Maestrichtian ; being more practic-
able the committee proposed to continue this usage.

However, until the type sections of the Senonian and Maestrichtian are studied in
detail and correlated more precisely, it is advisable to treat the Maestrichtian
separately from the Senonian. Thus in the present study, the Maestrichtian is
considered as an independent stage, younger than, and equal in rank to, the Senonian
stage as suggested by Jeletzky (1951), although it is clearly understood that the time
span represented by the Maestrictian is much shorter than that of the Senonian.
Again, the zone of Bostrycoceras polyplocum and its associated fauna which has been

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 19

wrongly considered to mark the base of the Maestrichtian, is here assigned to the
Upper Campanian, as the species, although rare in the Aquitaine Basin in general,
has been recorded in the type Campanian only (Jeletzky 1951 and Mrs. M. Séronie-
Vivien, personal communication). Moreover, in spite of the accumulated indisput-
able evidence for the Upper Cretaceous age of the type Maestrichtian, Hofker, in
several publications (1955-62), has argued for the time-stratigraphic equivalency of
the type Maestrichtian and the type Danian. Hofker’s claims were discussed by
Loeblich & Tappan (1957b) and Berggren (1962) who showed clearly that the true
stratigraphical relationship between the Danian and the Maestrichtian stages is one
of superposition and not lateral equivalence.

STRATIGRAPHICAL POSITION OF THE DANIAN

Desor (1846) introduced the Danian as the youngest stage of the Cretaceous
system, typified by the succession of the Cerithium, bryozoan, coralline and cocco-
lithic limestones, which disconformably overlies the Senonian white chalk of Denmark.
He considered these Danian deposits as equivalent to the so-called “ pisolitic lime-
stone ”’ which similarly overlies the Senonian white chalk disconformably at Laver-
sines and Vigny in the Paris Basin, and which were generally considered, at that
time, to be of Upper Cretaceous age. In his definition of this new stage he stated :
““M. Desor pense des lors qu’il faut envisager le calcaire de Faxoé, la craie corallienne
et le lambeau pisolithique de Laversine et de Vigny, comme un étage particulier de la
craie, le plus récent de tous, ainsi que l’avait proposé M. Elie de Beaumont ; mais il
ne saurait y comprendre les terrains a Nwmmulites, qu’il envisage comme étant d’une
époque plus récente. M. Desor propose d’appeler cet étage terrain danien, parce
qu'il est surtout développé dans les iles du Danemark. Ainsi que l’avait proposé
M. Graves, il est probable qu’on devra y rapporter par la suite le terrain de Maes-
trieht””.

Six years later, d’Orbigny (1852) described the fauna of the type Danian, and in
agreement with Desor, he considered it as the youngest stage of the Cretaceous
system, but clearly distinguished it from the underlying Maestrichtian. Since then
the same concept has been automatically followed by most stratigraphers, in spite
of the doubts about the true Cretaceous nature of the type Danian fauna. Indeed,
the Tertiary affinities of this fauna have been pointed out as early as 1823 by Forch-
hammer, (see Rosenkrantz 1960), long before the establishment of the term, and
later by Starkie Gardner (1884) and a few other authors.

On the other hand, Desor, in his original definition of the term, mentioned that the
beds of Maestricht may possibly be included within his Danian stage. This vague
statement led various authors to extend the Danian downwards in the succession
to include the Maestrichtian and even the Campanian, in spite of the marked strati-
graphical break between the Danian and the underlying strata in both the type
region of Desor and in other parts of the world. Thus, Mayer-Eymar (1872) consid-
ered the Danian to include the Campanian of Coquand, the Maestrichtian of Dumont
and the Danian of Desor, while Hébert (1875) extended the Danian downwards to

20 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

include the Maestrichtian rocks only. On the other hand Munier-Chalmas & de
Lapparant (1893) distinguished the Danian from the Maestrichtian, but extended
the former upwards in the section to include the Montian as its upper substage and
the typical Danian as its lower, including them both in the Cretaceous system.
Again, Geikie (1903) considered the Danian to include the Maestrichtian as its
lower part and the Montian as its upper, while Denizot (1936) considered the Mae-
strichtian to be distinct from the Danian, although he included it as a substage of the
latter.

This arbitrary use of the term Danian, resulted in the fact that the literature is
now filled with a considerable amount of wrong and confused information which led
to the vagueness and ambiguity of the term, and made it difficult to decide its true
stratigraphical position.

However, de Grossouvre (1897, 1901) considered both the Danian and the Montian
as a single unit in the basal Tertiary. He reasoned that as the Danian is devoid of
the index fossils which characterise the Cretaceous rocks below, such as the ammon-
ites, belemnites, inocerami, trigonias, rudists (Hippurites, Spherolites and Radtio-
lites), etc., the Cretaceous—Tertiary boundary should be drawn at the base of the
Danian. Unfortunately, this valuable remark was received with little enthusiasm,
and most stratigraphers continued to use the term Danian in the sense of Desor
(1846) and d’Orbigny (1852), as the youngest stage of the Cretaceous system.

Nevertheless, this logical explanation of the Cretaceous—Tertiary boundary
suggested by de Grossouvre, has started, since the early days of this century, to gain
the support of a few geologists, e.g. Brinnich-Nielsen (1920), Rosenkrantz (1920),
Harder (1922), Kayser (1924), Keller (1946), and Morozova (1939), who clearly
demonstrated the Tertiary affinities of the Danian fauna and thus advocated its
position at the base of the Tertiary.

Although faced with strong opposition and neglect at that time, this proposition
has recently received overwhelming support by a great number of stratigraphers,
e.g. Jeletzky (1951-1962) Brénnimann (1953), Troelson (1957), Loeblich & Tappan
(19574, b), Bolli (19576), Nakkady (1957), Bolli & Cita (1960a, b), Hay (1960), Lys
(1960), Reyment (1960a, 6) Burollet & Magnier (1960), Rosenkranz (1960) and
Berggren (1960), 1962). These recent studies have shown that the Danian, in its
type region and in various parts of the world is separated from the Maestrichtian
rocks below by a distinct faunal break which is generally accompanied by a physical
break of varying magnitude. The pronounced nature of this break and its world-
wide extent clearly mark the Maestrichtian—Danian boundary as the natural bound-
ary between the Mesozoic and the Cainozoic eras, and justifies the position of the
Danian at the base of the Tertiary system. At the Maestrichtian—Danian boundary,
all the Globotruncana, Rugoglobigerina, Trinitella, Plummerita, Abathomphalus,
Hedbergella, Globigerinelloides, Schackoina, Pseudotextularia, Pseudoguembelina,
Gublerina, Planoglobulina, Racemiguembelina, and Heterohelix, among a large number
of microfossils ; all the ammonites, the true belemnites (Belemnitellidae), rudists,

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 21

inocerami (?) ; all the mosasaurs, plesiosaurs, ichthyosaurs ; all the dinosaurs and
pterodactyls, etc. were found to die out completely and to be replaced in the over-
lying Danian by a different fauna where Globigerina, Globigerinoides, Globorotalia,
Chiloguembelina, typical Tertiary molluscan and echinoderm fauna, and primitive
placental mammals made their appearance for the first time. This geologically
abrupt extinction of several typical representatives of Mesozoic life at the Maestricht-
ian—Danian boundary, which is followed by an equally abrupt appearance of definite
Cainozoic forms in the Danian rocks above, and which is documented in both the
marine and non-marine domains, clearly marks this boundary as the major biochrono-
logical line between the Mesozoic and the Cainozoic Eras. This is substantiated by
the fact that this major break is also accompanied by a pronounced change in the
generic and specific composition of many other groups such as the molluscs (Rosen-
krantz 1960), the echinoderms (Poslavskaya & Moskvin 1960), the coccolithophorids
(Bramlette & Sullivan 1961), as well as by a physical break of varying magnitude and
world-wide extent. On the other hand, many other species and genera survived this
change and continued their development from the Maestrichtian into the Danian or
even later stages. These were used by various authors as an argument for the
Cretaceous and/or the transitional character of the Danian fauna, and hence their
preference to include the Danian within the Cretaceous system. However, this does
not minimize the importance of the distinct stratigraphical break between the
Maestrichtian and the Danian, as survival of certain members of the organic life
across similar major faunal breaks is reasonably understood and clearly documented
in the history of the earth. Moreover, contrary to Brotzen (1959), the faunal break
between the Maestrichtian and the overlying Danian is definitely much more
pronounced and widespread than any known breaks between the Danian and the
overlying stages, or between the Maestrichtian and the underlying stages. Therefore,
the Mesozoic—Cainozoic contact is naturally placed at this boundary which is, as
described by Jeletzky (1962), “a natural boundary based on a unique and easily
recognizable, major biochronological event apparently reflecting some kind of a
radical, world-wide change in the physical regime of our planet ”’.

Thus in the present study, the Danian is considered as the oldest stage of the
Tertiary system, and the Maestrichtian—Danian contact is taken to mark the
Mesozoic—Cainozoic boundary. This is in spite of the fact that various authors (e.g.
Brotzen 1959 and Yanshin 1960) have strongly argued for, and continued to use the
term Danian in the sense of Desor, as the youngest stage of the Cretaceous system.
However, neither of these authors could provide any evidence against the definite
Tertiary character of the Danian fauna or the marked faunal break between the
Maestrichtian and the overlying Danian. Brotzen simply stated “‘ To range the
Danian with the Cretaceous or the Tertiary is only a question of convention ’’, and
unjustifiably added “In my opinion no fundamental evidence has been adduced
which will necessitate changing the classical range of the Danian as the youngest
stage of the Cretaceous to the oldest stage of the Tertiary’”’. Yanshin built his
argument on a completely unsound basis and his paper is full of confusion and numer-
ous mistakes in matters of fundamental importance.

22 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

NATURE OF THE MEsozoIc—CAINOzoIC BOUNDARY

The traditional usage of the Danian as the youngest stage of the Cretaceous
system instead of its true position at the base of the Tertiary, has always concealed
the nature of the Mesozoic—Cainozoic boundary which in most parts of the world is
marked by a distinct stratigraphcial break.

In addition to the indisputable, major faunal break between the Maestrichtian
and the overlying Danian, the latter was found, in various parts of the world, to be
separated from the Cretaceous rocks below by physical breaks of varying magnitude.
In places, where the Upper Cretaceous—Lower Tertiary succession was described to
be conformable throughout, (e.g. Egypt), unconformities and disconformities are
being discovered with further detailed examination of the previously described
sections (e.g. Farafra, Dakhla and Kharga Oases and the Esna—Idfu region). In
places where the lithology on either side of the contact does not permit the detection
of the physical break, the abrupt extinction of numerous, diverse representatives of
Cretaceous life, and the sudden appearance of new Tertiary forms, clearly mark the
Mesozoic—Cainozoic contact.

Although evident and clearly documented, such a distinct, sharp and world-wide
break at the Maestrichtian—Danian boundary, represents one of the most enigmatic
problems in the history of the Earth. It is beyond the scope of the present work to
try to explain it, but it clearly points to the fact that the life record between the
uppermost Maestrichtian and the lowermost Danian, as we know it, is incomplete
and may possibly be sought for in the deep oceanic troughs, or in yet undescribed
sections, where a complete Cretaceous—Tertiary sequence may be found. Moreover
it reflects, as previously mentioned by Jeletzky (1962) ‘“‘ some kind of a radical,
world-wide change in the physical regime of our planet ’’, which may be regarded as a
“catastrophe ” or a “ revolution ’’, and which still awaits further explanation.

STRATIGRAPHICAL POSITION AND CLASSIFICATION OF THE PALEOCENE

Schimper (1874) introduced the term Paleocene to distinguish the lowest part of
the Tertiary system, which was then included at the base of the Eocene. He used
this term to describe the “‘ Travertin de Sézanne ”’ in the eastern part of the Paris
Basin, which he considered on the basis of its floral content to be worthy of distinc-
tion from both the younger Eocene and the older Upper Cretaceous series. The
conglomerates of ‘“‘ Meudon” and “ Cernay”’ which are characterized by their
mammalian fauna were also attached to the Paleocene and were found to mark the
limits of a sedimentary cycle which followed the Cretaceous chalk and preceded the
“ Nummulitic transgression ’’.

Thus the Paleocene was generally considered to represent one sedimentary cycle
spanning the time between the uppermost Cretaceous and the basal Eocene, although
the controversy about the true position of these two boundaries made it difficult to
establish the boundaries of the Paleocene series. For example, the so called “ piso-
litic limestone’ of Laversines and Vigny and its equivalents, in the Paris Basin

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 23

which represent the first marine transgression over the truncated surface of the
Upper Cretaceous Chalk, were repeatedly assigned to the Campanian, Maestrichtian
or Danian. As a result, these beds were generally excluded from the Paleocene,
although they have been recently proved to be of definite basal Tertiary age and
correlated with the “‘ Tuffeau de Ciply ””’ of Belgium (Damotte & Feugueur 1963).
Similarly the lagoonal, clayey and lignitic deposits which lie between the “ Cernay
conglomerate ”’ or its equivalents and the base of the Cuisian, were included by some
authors within the Paleocene, while others placed them at the base of the Eocene.
Therefore, the Paleocene in the Paris Basin was very poorly defined and was generally
taken to include various rock units between the Upper Cretaceous and the basal
Eocene such as the “ Tuffeau de la Fere’”’ and the “‘ Argile de Vaux-sous-Laon ”’ ;
the “ Sables de Bracheux et de Chalons-sur-Vesle ”’ ; the “ Travertin de Sézanne ”’ ;
the “‘ Calcaire de Rilly ” and the ‘“‘ Conglomerat de Cernay ’’, and by some authors
the “ Argile plastique ”’ and the “ Lignites du Soissonnais ”’ as well, but its lowermost
and uppermost limits remained uncertain. Moreover, the fact that the Paleocene,
as defined above, in its type region, is represented by non-marine and very near-
shore deposits which were mainly zoned on the basis of their floral and mammalian
contents, made any correlation with the corresponding marine deposits practically
impossible. The shallow water marine fauna of the “ Sables de Bracheux ”’ and its
equivalents, which were described by Farchad (1936) and Rouvillois (1960) proved
to be largely of a localized nature and hence, of little value in correlation.

As a result, various authors, e.g. Mangin (1957), suggested that the term Paleocene
should be dropped altogether and the Eocene be extended downwards (as it was
originally defined) to include at its base the youngest Lower Tertiary formations.
However, the fact that the Paleocene, in its type region and in other parts of the
world is generally represented by a particular sedimentary cycle and/or biological
unit, distinguished from that of the overlying Eocene, favours its separate treatment.

On the other hand, long before the introduction of the term Paleocene, several
stages had been established to describe various segments of the succession represent-
ing the time span between the uppermost Cretaceous and the basal Eocene, e.g. the
Landenian (1839), the Heersian (1851), the Montian (1868) and the Thanetian (1873).
In addition various stages were introduced later, e.g. the Sparnacian (1877), the
Seelandian (1924) and the Ilerdian (1960). Moreover, the Danian which was
wrongly introduced (1846) as the youngest stage of the Cretaceous system, was
proved, as stated above, to represent the oldest stage of the Tertiary, and is thus
included as the lowest stage of the Paleocene series. However, as these type sections
are widely spaced, were designated by different authors, and are represented by
different facies (continental, lagoonal, shallow-water and deep-water marine deposits),
it became difficult to establish the true stratigraphical relationship between one
stage and the other, and between each stage and the corresponding part in the type
area of the Paleocene. Nevertheless, to avoid the difficulty of correlation with the
peculiar facies of the type Paleocene in the Paris Basin, different authors tended to
use various sets of the above-mentioned stage names to represent the basal Tertiary,

24 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

as subdivisions of the Paleocene, or within the basal part of the Lower Eocene.
Moreover, they tried to introduce these stage names to the type Paleocene, but the
relationship between one stage and the other was not clearly understood, and was
arbitrarily interpreted by the individuals concerned. Thus, while the Paleocene in the
Paris Basin was regarded as including the Thanetian and Sparnacian ; the Montian,
Thanetian and Sparnacian ; the Montian and Thanetian ; or the Thanetian alone,
it was taken to include the Montain and Landenian in southern Belgium ; the
Montian, Heersian (with or without the Infra-Heersian) and Landenian in north-
eastern Belgium and in Holland ; the Thanetian, with or without the Woolwich and
Reading Beds in England ; the Seelandian, Thanetian and Landenian in Sweden and
Denmark, and any further combination of these, plus or minus the Danian. More-
over, because of the confusion about the true chronological relationship between the
Danian and the Montian, Sigal (1949), followed by most Mediterranean geologists,
introduced the Dano-Montian as a new term to cover the early Paleocene period.

However, in his study of the basal Tertiary in the Franco-Belgian Basin, Feugueur
(1955, 1962, 1963) included the Paleocene within the Lower Eocene and equated the
Cuisian with the Upper Ypresian, the Sparnacian with the Lower Ypresian, and the
Thanetian of the Paris Basin with the Landenian of Belgium, although he pointed out
the fact that the Lower Landenian (—Heersian) is missing in the Paris Basin.
Feugueur followed Leriche (1903) who had previously recognized in the Landenian
a marine lower division and a continental upper one, and divided the marine Lower
Landenian, on the basis of its shallow water molluscs, into three zones, from the
base upwards: the Arctica morrisi Zone, the Pholadomya oblitterata Zone and the
Arctica scutellaria Zone. However, Feugueur considered the latter zone to be of
lagoonal, rather than of marine origin and attached it to the overlying Upper Land-
enian, which he regarded as comprising the lagoonal Arctica scutellaria Zone at its
base and the continental Physa gigantea Zone on top. On the other hand, while
Feugueur equated the so-called “‘ Thanetian of the Paris Basin’ with the Landenian
of Belgium, and noted that the basal Landenian (= Heersian=Arctica morrist Zone)
is missing in the Paris Basin, Arctica morrist was found to mark the top of the
Thanetian in England. In spite of this fact, the so-called Thanetian in the Paris
Basin has always been equated with the Thanetian of England, which is apparently
much older. Thus, despite the value of Feugueur’s correlation in the Anglo-I*ranco-
Belgian basin, several problems in the same basin were left unexplained. The
relationship between the Thanetian of England and the Thanetian of the Paris
Basin ; the Thanetian of England and the Landenian of Belgium ; the Thanetian,
the Landenian and the Montian ; the Montian and the Danian ; the Danian and the
Heersian ; and the Heersian and the Montian are still not clear. Moreover, the
relationships of the other type stages of the Paleocene outside the ‘‘ Anglo-Franco-
Belgian Basin ”’ to each other and to those in the basin were left unsolved. It is not
really understood what sort of chronological relationship exists between the Danian
and Montian, the Montian and Seelandian, the Montian and Landenian, the Thanetian
and Landenian, the Montian, Thanetian, Landenian and the Ilerdian, in their
respective type areas. Nevertheless, selected sets of these stage names were

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 25

arbitrarily used by various authors to represent the Paleocene, but were differently
interpreted and much confused.

Loeblich & Tappan (1957a, b) divided the Paleocene into a lower and an upper
stage which they equated with the Danian and Landenian respectively. They
(19574) suggested the inclusion of the Thanetian as the lower substage of the Landen-
ian and the Sparnacian as the upper one, although they mentioned (19570) that the
Sparnacian may represent both late Paloecene and early Eocene time. These
authors recorded the occurrence of G. daubjergensis Bronnimann and G. triloculi-
noides Plummer in the lower part of the type Montian (the “‘ Tuffeau de Ciply ’’),
and thus considered the type Montian as the lateral equivalent of the type Danian,
and stated ‘‘ The occurrence of the Cerithium fauna in the type Danian, and the
Nautilus danicus in Montian equivalents, the species of the daubjergensis-compressa
faunal zone represented in both type Danian and type Montian and their equivalents
over the world, the identical stratigraphic position of the Danian and Montian, each
unconformable on the Cretaceous, and underlying the Landenian sediments, and the
fact that they are never found together, leads inescapably to the conclusion that the
Danian and Montian are merely different lithologic and faunal facies of identical
geologic age. We suggest that the term Danian be used to include the Montian
also, inasmuch as the type Danian includes beds of both facies. The Danian should

,

be used as a stage name within the Paleocene ’’.

Loeblich & Tappan’s proposition was previously mentioned by de Grossouvre
(1897) and Harder (1922), and is followed by a number of authors, in spite of the fact
that Vincent (1928), Ravn (1933), Chavan (1946), Marie (1950), Hofker (19614, 19622),
Moskvin & Naidin (1960) and Voigt (1960) have strongly emphasized the fact that
the type Montian is younger than the type Danian.

Hofker (1961a) recorded the occurrence of Globorotalia pseudomenardu Bolli,
Globorotalia ehrenbergi Bolli and Globorotalia pusilla laevigata Bolli in the lower part
of the type Montian (the “ Tuffeau de Ciply ’’), and thus correlated the Montian with
the Globorotalia pusilla pusilla and the Globorotalia pseudomenardu Zones of Bolli
(19576). On these grounds, he considered the Montian to be of Middle Paleocene
age and introduced what he described as the Lower Paleocene between the Danian
and the Montian, correlating it with the Seelandian of Brotzen (1948), and stating
that “ Alors, il n’y a plus de doute : le Montien-type, vers sa base, est déja du
Paléocéne moyen et il est impossible de paralléliser le Montien avec le Danien ;
il y a un étage entier entre le Danien et le Montien, représenté par le Tuffeau glau-
conieux, qui, déja est du Paléocéne, comparable aux couches plus basses du ‘ Lizard
Springs formation du Trinidad’’’. Moreover, he added that the benthonic Fora-
minifera of the “ Calcaire grossier de Mons ’’, which forms the upper part of the type
Montian, leaves no doubt about its Upper Paleocene age, although the planktonic
Foraminifera are very rare and do not form a typical association. He further
complicated the problem by considering the Montian as the upper part of the Lower
Paleocene and the G. trinidadensis—G. uncinata Zones of Bolli as representing the
lower part of this Lower Paleocene, which overlies the Danian. Again, he stated that

26 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

the Landenian overlies the Montian, and that it contains in its lower part a benthonic
foraminiferal fauna comparable to that of the Thanetian of England, but with no
pelagic forms. He did not state to which part of the Paleocene the Thanetian
belongs if the “‘ Calcaire de Mons ”’ is considered to be of Upper Paleocene age as he
suggests.

Thus, in a single paper, Hofker considered the Montian to be equivalent to the
upper part of the Lower Paleocene, to be Middle Paleocene in age and (as the “ Cal-
caire de Mons’’) to be of Upper Paleocene age. However, the existence of G.
daubjergensis Brénnimann in the “ Tuffeau de Ciply ’’, discovered by Loeblich &
Tappan (19570), confirmed by the present author, by Gartner & Hay (1962) and by
Berggren (1963), throws doubt on the validity of Hofker’s record, especially of G.
pseudomenardu and G. pusilla pusilla. In the Esna—Idfu region and in other parts
of the world, the last mentiond species occur at a much higher level in the Paleocene
succession than the uppermost limit of G. daubjergensis. Moreover, the writer has
examined washed residues of the “ Tuffeau de Ciply’”’ in Dr. Hofker’s possession
and others placed by him in the collection of the Geological Museum at Haarlem
but could not trace these species, in spite of Hofker’s statement that he had found
them in abundance. On the contrary, in the latter collection, forms such as G.
tvimdadensis Bolli and G. uncinata uncinata Bolli (together with undescribed forms)
deny the possibility of the existence of G. pseudomenardi in the “‘ Tuffeau de Ciply ”’.
The present author has sampled the type ““Tuffeau de Ciply ’’, and the outcrop of
the ‘“‘ Calcaire de Mons ’”’ at the “ Trenchée de Hainin”’ in the Mon’s basin. These
samples together with one from the type “ Calcaire de Mons ”’ of the “‘ Puits Goffint ”
and several Montian samples from drilling in the Mons and the Landen Basins,
kindly provided by Mr. M. Gulinck and Professor R. Marliére, are still under study.
Until this study is completed no decision can be reached regarding the true strati-
graphical relationship between the Danian and the Montian. However, authors
have already divided into three groups ; one advocating the time-stratigraphic
equivalency of the type Danian and the type Montian ; another claiming a much
younger age for the Montian and placing it higher in the Paleocene; and a third
who clearly realizes the close similarity between the Danian and Montian faunas,
but who still advocates placing the Montian on top of the Danian.

In support of the latter proposition, Voigt (1960) stated that ““ Researches now in
progress of the bryozoa of the Montian in Belgium and Holland show very close
relationship to the bryozoan fauna of the Danian, however ; a considerable part of
foreign, in part new, species still leaves a possibility for the lower Montian, the
“ Tuffeau de Ciply ’’, to be younger than upper Danian.”

In agreement with Voigt (1960) Moskvin & Naidin (1960) recorded the occurrence,
in southwestern Russia (Crimea, Caucasus and Transcaspian Oblast), of a limestone
horizon with a molluscan fauna similar to that described from the type Montian,
directly overlying bryozoan and crinoidal limestone with typical Danian fauna.
Thus these authors concluded that the time-stratigraphic equivalency of the type
Danian and the type Montian as suggested by Loeblich & Tappan (19574, b) is

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT ZG]

practically impossible. However, because of the close relationship of the fauna,
they considered the Montian as the upper substage of the Danian as previously
suggested by Munier-Chalmas & de Lapparent (1893), and divided the Paleocene
into a lower, Danian and an upper, Thanetian stage.

On the other hand, Gartner & Hay (1962) recorded the occurrence of a specimen
closely resembling Globigerina daubjergensis Bronnimann in the “ Tuffeau de Ciply ”’.
This record is confirmed by the present author, and by Berggren (1963) who recorded
this species together with Globigerina triloculinoides Plummer and Globorotalia
pseudobulloides (Plummer) at the base of the same formation. Berggren quoted
Wienberg-Rassmussen (1962) who considered the “‘ Tuffeau de Ciply ’’, on the basis
of its Echinoderm fossil content, to be of definite Danian, and presumably Middle
Danian age, and concluded that “... the lower Montian (Tuffeau de Ciply) is time-
equivalent with the lower and middle Danian of Denmark ; the relationship between
the upper Montian (Calcaire de Mons) and the upper Danian remains uncertain. By
extrapolation it is probably correlative in part with the upper Danian, and, in part,
younger than known, exposed Danian in Denmark. It is also possible that sub-
surface younger Danian in Denmark may fill the missing void in our information ...’’.

Loeblich & Tappan (19575), also studied samples from both the type Thanetian
and the type Sparnacian and stated that no planktonic Foraminifera were found in
the samples from these sections. They quoted Haynes (1955) who had previously
recorded Globigerina triloculinoides Plummer, G. pseudobulloides Plummer and
G. velascoensis (Cushman) aff. var. acuta Toulmin from type Thanetian samples.
Thus they equated the Thanetian with “‘ the highest Paleocene planktonic faunal
zone—the Globorotalia velascoensis—acuta Zone’’. However, on their correlation
diagram (19574, fig. 28) they equated the Sparnacian with this zone, which they
considered as the upper subzone of their ‘“‘ Landenian ”’ angulata Zone, while they
regarded the Thanetian as the lower part of this zone, the pseudobulloides Subzone.

However, examination of Globorotalia velascoensis (Cushman) aff. var. acuta
(Toulmin) of Haynes (1955, 1956) from the type Thanetian of England, has
shown that it is a reworked Upper Cretaceous Globotruncana species. The state of
preservation of the specimen does not allow its specific identification with certainty,
but the occurrence of reworked Upper Cretaceous species in the type Thanetian was
mentioned by Haynes (1956), and these species have been studied by Haynes and
El-Naggar (in press). The same conclusion has been reached independently by
Berggren & Barr (in Berggren 1963).

Nevertheless, this record by Haynes (1955, 1956) was used by Loeblich & Tappan
(19574, 6), Bolli & Cita (1960 a, b), and several other authors as a basis for correlating
the type Thanetian with the Globorotalia velascoensis Zone of Upper Paleocene age.
However, examination of several type Thanetian samples has shown that they
contain a mixture of Senonian and Danian forms. The existence of such forms as
Globigerina dauljergensis, G. triloculinoides, Globorotalia pseudobullotdes, G. trinidad-
ensis, G. quadrata, which are clearly Danian in age, with forms such as Globotruncana
cretacea, G. linneiana linneiana, G. fornicata fornicata, G. rosetta rosetta, G. tricarinata

28 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

tricarinata, and abundant Rugoglobigerina, Hedbergella and Globigerinelloides species,
which indicate an Upper Senonian, pre-Maestrichtian age, and the entire absence of
typical Maestrichtian forms, represent one of several enigmatic problems about the
true stratigraphical position of the Thanetian, and the geological history of England
during the Cretaceous—Tertiary transition period. The existence of mixed Senonian
and Danian fauna in the type Thanetian may be explained by the suggestion that the
whole planktonic foraminiferal content is reworked from previously existing Senonian
and Danian strata, although no Danian deposits have yet been recorded anywhere in
the British Isles. This may be substantiated by the record, in the type Thanetian,
of a meagre calcareous nannoplankton assemblage which also occurs in the “G.
pseudomenardu Zone of Trinidad ’”’ (Bramlette & Sullivan 1961). On the other hand,
it could suggest that while the Senonian forms are reworked from the underlying
chalk, the Danian ones are possibly indigenous ; hence the type Thanetian may
include strata which are equivalent to the type Danian. This conclusion is doubted
here owing to the absence of a typical Danian macrofauna and fauna of benthonic
Foraminifera. However, the author refrains at present from taking any decision
about the true stratigraphical position of the Thanetian until its type sections are
examined in detail and correlated with the other type sections of the various stages
of the Paleocene, and with the Paleocene in other parts of the world. Nevertheless,
the Thanetian of England is probably different from the Thanetian in the Paris Basin ;
while Arctica morrist marks the top of the former, it is supposed to underlie the
latter. This simply points to the fact that the true stratigraphical position of the
Thanetian, like that of the Montian, is not yet clearly understood and that the vague
use of these terms in Paleocene stratigraphy is far too dangerous at the moment.

Loeblich & Tappan (19575) also mentioned the difficulty in correlating the Sparna-
cian, as it is represented in its type section by non-marine facies. However, they
mentioned that as the non-marine Woolwich and Reading Beds and the underlying
marine Thanet Beds of England, are considered as deposits of one and the same
sedimentary cycle (Stamp I92I ; Haynes 1955), the non-marine type Sparnacian
is more probably related to the Paleocene. Moreover, they stated that ‘“ Until
marine strata referable to the Sparnacian can be obtained this problem is difficult
to solve. It may represent both late Palocene and early Eocene time’”’. However,
on their correlation diagram they considered the Sparnacian as the upper substage
of the Landenian, although Feugueur (1955, 1962, 1963) has constantly advocated
the time-stratigraphic equivalency of the type Sparnacian and the lower Ypresian.

This brief discussion clearly indicates the great difficulty in correlating the various
stages and substages of the Paleocene, because of the non-marine, or very near-shore
facies of most of the type sections, and the uncertainty about their true chronological
relationship. It also indicates that the assignment of the various planktonic
foraminiferal zones by Loeblich & Tappan (19574, b), Bolli (1959), Bolli & Cita
(1960a, b), Hofker (1961a, 1962a) and various other authors, to the Montian, Thanet-
jan, Sparnacian, or Landenian, is rather arbitrary and is not based on any proper
correlation with the type sections.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 29

To overcome the difficulty of correlating marine and non-marine deposits and the
uncertainty resulting from such correlation, Hottinger & Schaub (1960) proposed the
Ilerdian as a new stage to represent the marine Upper Paleocene. These authors
studied the larger Foraminifera of this new stage and stated that it has no equivalent
in the Paris Basin, but added ‘“‘ We only know that it is immediately below the
Cuisian. Very likely it lies between the Cuisian and the marine phase of the Montian.
So far we had no opportunity to determine whether a part—and in the affirmative
case, which part—of this stage corresponds with the marine phase of the Landenian.”’

Gartner & Hay (1962) studied the planktonic Foraminifera of the type Ilerdian,
and affirmed its Upper Paleocene age. However, examination of several Ilerdian
samples from Mont Cayla, kindly presented by Miss M. Toumarkine of the Sorbonne,
has shown that these deposits are of Lower Eocene, rather than of Paleocene age
(see discussion under each of the species recorded by Gartner & Hay 1962). This
throws doubt on Hottinger & Schaub’s conclusion, on Gartner & Hay’s identifications
and on the validity of the Ilerdian as a stage of the Paleocene. The use of the term
Ilerdian in Paleocene stratigraphy is therefore considered inadvisable, especially
as the relationship of the ‘‘ Ilerdian” to the other stages and substages of the
Paleocene is not yet understood. [The type section of the [lerdian in the Tremp
basin, as well as several other Ilerdian outcrops in Spain and in France, have been
sampled in detail by the present author in an attempt to discover their true strati-
graphical positions. |

In the present study, the Paleocene is considered to be a distinct series at the base
of the Tertiary system, older than, and equal in rank to, the Eocene series. It spans
the time between the top of the Cretaceous and the base of the Eocene, and includes
the Danian as its lowest stage. The controversy about the chronological and
stratigraphical relationships of the various stages and substages of the Paleocene
(other than the Danian) as summarized above, necessitates the temporary abandon-
ment of these terms and the use of faunal zones instead. The establishment of
faunal zones which are built on the basis of evident evolutionary trends, and which
can be correlated in various parts of the world, is the only solution at the moment to
the numerous problems in Paleocene stratigraphy. Correlation of the type sections
of the various stages and substages of the Paleocene with these zones is bound to
show the true stratigraphical relationship between one stage and the other, and will
lead to the development of a reliable means of correlation for this series.”

The present study has shown that in Egypt and elsewhere, the Paleocene is
divisible into three faunal zones in which the planktonic Foraminifera represent
a continuous evolutionary sequence showing clearly recognizable trends. Each of
these zones corresponds to a definite evolutionary stage. They are as follows :

1. A lower zone marked by the first appearance at its base of the genera Globoro-
talia and Globigerina, and characterized by an assemblage of Globigerina and globi-

2 The relationship between these stages has now been clarified and the suggested stage names are
discussed elsewhere (El-Naggar, in press), and inserted on some of the accompanying figures.

30 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

gerina-like, rounded, non-keeled Globorotalia. These globorotalias are generally
smooth-surfaced, with a tendency towards the development of a slightly roughened
surface and a gently compressed test upward in the section. This zone is character-
ized by the presence of Globorotalia pseudobulloides (Plummer), G. trinidadensis
Bolli, G. compressa (Plummer), Globigerina triloculinoides Plummer and G. daub-
jergensis Bronnimann among other species, but as both Globorotalia compressa and
Globigerina daubjergensis are found to die out completely at its top, they are taken as
the index species of the zone, which is known as the Globorotalia compressa/Globi-
gerina daubjergensis Zone. The planktonic Foraminifera of this zone characterizes
the Danian in its type section and the known Danian deposits elsewhere, thus it is
taken to represent the Danian, or the oldest stage of the Paleocene series. The
lower limit of this zone marks the Cretaceous—Tertiary contact, and its upper limit is
marked by the disappearance of its index species and the first appearance of the
truncated Globorotalia which characterize the following zone.

2. A middle zone characterized by an assemblage of Globigerina and truncated,
non-keeled Globorotalia, in addition to the rounded form which first appeared in the
underlying zone. At the base of this zone, most representatives of the genus
Globorotalia (generally rounded or slightly compressed in the underlying zone) start
to become flattened on the dorsal side and strongly protruding on the ventral, with
the development of an acute axial periphery, but with no keel, or only a partially
developed, incipient one. Again the tendency towards the development of a rough-
ened surface, flattening of the dorsal side and the development of a sharply acute
axial periphery and a partial keel, increases gradually upwards in the section. An
excellent example of these truncated globorotalias is G. angulata angulata (White)
which is taken as the index species of this zone, although it continues in the over-
lying zone. The development of G. angulata angulata from the typically rounded
form G. pseudobulloides (Plummer) through G. trvinidadensis Bolli and G. uncinata
uncinata Bolli is clearly documented (Text-fig. 15), and demonstrates the tendency
of Globorotalia to develop from rounded to truncated forms upwards in the section.
On the other hand, G. angulata angulata also demonstrates the evolutionary develop-
ment of the truncated, non-keeled Globorotalia into the sharply-keeled ones by the
development, in the overlying zone, into G. velascoensis velascoensis (Cushman)
through G. angulata abundocamerata Bolli. This, added to the fact that the first
appearance of G. angulata angulata coincides with the disappearance of the index
species of the underlying zone which represents the lowest Paleocene or the Danian,
and that G. angulata angulata was never recorded from the type Danian, justifies the
position of the G. angulata Zone at the Middle of the Paleocene series. From an
evolutionary point of view, this zone with truncated Globorotalia is regarded as a
transitional stage between the underlying rounded Globorotalia Zone and the over-
lying zone with sharply-keeled Globovotalia. This is also substantiated by the fact
that this intermediate zone is represented by a relatively smaller thickness of strata.
However, as its characteristic assemblage of planktonic Foraminifera can not be
assigned to either the overlying or the underlying zones, it is advisable to treat
it separately. The lower boundary of this zone is marked by the first appearance

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT Bi

of its index species, and its upper boundary is marked by the first appearance of the
sharply keeled Globorotalia assemblage, typified by G. velascoensis velascoensis
(Cushman) and G. pseudomenardu Bolli.

3. An upper zone characterized by an assemblage of rugose Globigerina and
sharply-keeled and/or rugose Globorotalia species. In this zone, the tendency
towards the development of a marginal keel and/or a rugose surface which started
with the early representatives of Globorotalia in the Lower Paleocene, is fully
achieved. At the bottom of this zone the first known sharply-keeled Globorotalia,
represented by G. velascoensis velascoensis (Cushman) and G. pseudomenardi Bolli,
make their appearance. G. pseudomenardi dies out towards the middle but G.
velascoensis velascoensis continues to the top, where it dies out completely. Globoro-
talia velascoensis with its three subspecies, G. velascoensis velascoensis, G. velascoensis
parva, and G. velascoensis caucasica, represent the dominant forms of the zone which
is thus known as the G. velascoensis Zone. This zone is considered to represent the
Upper Paleocene in Mexico, in the Gulf and Atlantic Coastal Plains of the U.S.A.,
in the Caribbian region, in Southern France, in Italy, in North Africa, in the Middle
Fast, in Pakistan—India—Burma region, in New Zealand and in the U.S.S.R., although
the characteristic species are not recorded in the type Upper Paleocene of Western
Europe (the Landenian) which is mainly of continental and lagoonal facies. However,
as previously mentioned, the sharply keeled Globorotalia assemblage of the G.
velascoensis Zone represents the maximum development of a continuous evolutionary
trend which started at the base of the Paleocene, typified by the bio-series : Globoro-
talia pseudobulloides—G. trinidadensis—G. uncinata uncinata—G. angulata angulata+
G. angulata abundocamerata—G. velascoensis velascoensis (Text fig. 15). This
continuous evolutionary sequence is paralleled by similar lineages throughout the
Paleocene, and proves that there are three distinct stages in the development of the
genus Globorotalia : the rounded stage, the truncated stage and the sharply keeled
stage. It also justifies consideration of these three stages as divisions within one
natural unit, hence the position of the G. velascoensis Zone as the Upper Paleocene and
the underlying two zones as the Middle and Lower Paleocene respectively. Analysis
of previously recorded planktonic Foraminifera in the Paleocene of different parts
of the world, shows the existence of these three stages, and thus substantiates the
division of the Paleocene proposed here.

THE PALEOCENE—LOWER EOCENE BOUNDARY

The fact that the Upper Paleocene in its type region is represented by non-marine
sediments, and that the planktonic Foraminifera in the type Lower Eocene are
hardly known, made it difficult to decide the position of the Paleocene-Lower
Eocene boundary with certainty. However, as previously suggested by Bolli
(19574, 19590), Loeblich & Tappan (19574, b) and Bolli & Cita (19Q60a, 6), and as
reasoned above, this boundary is drawn at the top of the Globorotalia velascoensis
Zone, although Olsson (1960) included the latter zone within the Lower Eocene.
Analysis of the planktonic foraminiferal content of the G. velascoensis Zone shows
clearly that it has more species in common with the underlying Paleocene zones than

32 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

with the overlying G. wilcoxensis Zone which is here taken to mark the base of the
Eocene. Moreover, as mentioned above, the planktonic Foraminifera of the G.
velascoensis zone constitute, with those of the underlying Paleocene zones, a contin-
uous evolutionary series which unites them as one natural unit. On the other hand,
the disappearance of several typical Paleocene forms at the base of the G. wilcoxensis
Zone and the appearance of new forms and new evolutionary tendencies, clearly
distinguishes this zone from the underlying Paleocene. In the G. wilcoxensis
Zone, a tendency towards reduction in the size of test and increase in the surface
rugosity and/or the degree of development of the marginal keel in the genus Globoro-
talia, is clearly documented. As a result the majority of the planktonic Fora-
minifera in this basal Eocene zone have a highly rugose surface and/or a very well
developed marginal keel. In this connection, it is worth noting that the rare
planktonic forms recorded by Kaasschieter (1961) from the type Ypresian of Belgium,
although misidentified, are highly rugose, as are all the forms recorded by Berggren
(1960a) from the Ypresian of Denmark and northwestern Germany. Moreover, the
planktonic Foraminifera of the G. wilcoxensis Zone clearly correlate it with the basal
Eocene of Mexico, the Gulf and Atlantic Coastal Plains of the U.S.A., the Carib-
bean region, Denmark, northwestern Germany, southern France, Italy, North Africa,
the Middle East, Pakistan—India—Burma region, New Zealand and the U.S.S.R.,
where similar planktonic foraminiferal assemblages have been recorded. This is
substantiated by the fact that in the sections studied, a flood of Nummutlites, Oper-
culina, Assilina and Discocyclina, amongst numerous typical Eocene forms, is
clearly observed in the G. wilcoxensis Zone, while the genus Nummulites, represented
by rare specimens of the very primitive form NV. deserti de La Harpe, is alone recorded
in the uppermost part of the underlying zone. However, a detailed study of the
planktonic Foraminifera in the type Lower Eocene is needed before a definite
decision on the position of the Palecoene/Lower Eocene boundary can be reached.

B. THE UPPER CRETACEOUS-LOWER TERTIARY IN EGYPT

The classification of the Upper Cretaceous—Lower Tertiary rocks of Egypt was
first attempted by Zittel (1883), who considered the fossiliferous marine succession
overlying the Nubia sandstone of the Western Desert Oases to belong collectively to
the Danian, which he regarded as the youngest stage of the Cretaceous system. As
a result, he assigned the underlying unfossiliferous Nubia sandstone to the Upper
Senonian, while he considered the nummulitic limestone beds which cap the succes-
sion to be of Lower Libyan (Lower Eocene) age. However, he overlooked the
succession of shales between the top of his Danian and the base of the nummulitic
limestone, which were later recorded by various authors in the Oases and in other
parts of Egypt, and were considered by Beadnell (1905) as passage beds between the
Cretaceous and the Tertiary systems. Moreover, Zittel advocated the absolute
conformity of the Cretaceous—Tertiary succession in southern Egypt, a concept
which, as discussed below, was uncritically followed by most stratigraphers and led
to great confusion.

Zittel classified the strata he considered to be Danian in the Western Desert Oases

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 33
into three distinct rock units which he described from the base upwards as follows :

1. Beds of Exogyra overwegi von Buch, (Overwegischichten).
2. Greenish and ashen-grey paper-like shales.
3. Snow-white, well-bedded limestones or earthy chalk with Ananchytes ovata.

The fossils collected by Zittel from these three rock units were described by Quass
(1902) and Wanner (1902) who confirmed Zittel’s classification, assigning all these
rock units to the Danian. Moreover, Quass considered Zittel’s shale and chalk units
as two different facies of the same stratigraphical horizon, which he regarded as the
Upper Danian.

Apparently Zittel used the term Danain in a much broader sense than that of the
original definition of the term. While no known ammonities or inocerami are
recorded to range up into the type Danian, Zittel recorded the genera Libycoceras,
Baculites and Inoceramus in his “‘ overwegischichten ’’, but still included it in the
Danian. Probably he was confused by Mayer-Eymar (1872) who had extended the
Danian to include the Campanian, the Maestrichtian, and the Danian proper and
thus added to the confusion regarding the limits between these stages and sub-stages.
However, analysis of Zittel’s Danian in the light of the present investigation shows
that it includes the Upper Campanian, the Maestrichtian and most of the Paloecene.
It also indicates a marked break between the Maestrichtian and the overlying
Paleocene strata in spite of Zittel’s emphasis on the absolute conformity of the succes-
sion. Nevertheless, Zittel’s concept and classification of the Danian in Egypt were
generally followed by later authors, e.g. Ball (I900), Beadnell (1901, 1905), Oppenheim
(1902) and Hume (1911), where the latter included as Danian all the succession of
strata between the top of the Campanian and the base of the Lower Eocene.

‘

Blanckenhorn (1900) considered Zittel’s “‘ overwegischichten ”’ to belong to the
Maestrichtian, which he equated with the Dordonian, Upper Aturian and Lower
Danian. Later in 1921, he reconsidered the “ overwegschichten ”’ to belong to the
Campanian and related the other two divisions to the Danian (which he regarded as
the youngest stage of the Senonian), ignoring completely the Maestrichtian.
Apparently he followed de Grossouvre (1897, 1901) who had included the Maestrich-
tian within the Campanian as its uppermost part. However, Fourtau (1904),
following Arnaud (1897), considered the Upper Senonian to include the Campanian
as its lower horizon and the Maestrichtian as its upper, while he regarded the Danian
as a distinct stage, younger than and equal in rank to the Senonian stage. He also
considered some fossils of Zittel’s ““ overwegischichten ” to belong to the Campanian
and reasonably stated that the limit between the Maestrichtian and the Danian in
Egypt should be drawn at the top of the highest bed with ammonites.

Beadnell (1905) classified the Upper Cretaceous—Lower Tertiary rocks of the Nile
Valley, south of Esna, into Campanian, Danian, Passage beds and Lower Libyan,
advocating the absolute conformity of the succesion which was previously emphasized
by Zittel (1883). Following the general belief of his time, he ignored the Maestricht-

34 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

ian, probably including it within the Campanian, and considered the Danian as the
youngest stage of the Cretaceous system, but he did not state to which system his
“Passage beds’ belong. Thus he assigned the oyster limestone and the associated
bone beds, which directly overlie the Nubia sandstone, to the Campanian, and the
overlying succession of shales, marls and chalks to the Danian which he correlated
with Zittel’s Danian of the Western Desert Oases. He regarded the shales between
the top of the Danian and the base of the nummulitic limestones above, (Beadnell’s
Esna shales), as passage beds between the Cretaceous and the Teritary and referred
the overlying nummilitic limestones to the Lower Libyan (Lower Eocene) (see
Text-fig. 4).

Hume (1911) classified the same succession as Campanian, Danian and Lower
Eocene, including Beadnell’s Passage beds within his Danian. He correlated this
succession with others in the Western Desert Oases, in Wadi Quena and in northern
Sinai. He also used these widely-spaced sections to demonstrate the gradual advance
of the Upper Cretaceous sea over the Egyptian territory, invading it from the north-
east, depositing limestones in the northern part, sandstones in the south, and shales,
marls and chalks in between. The relative distribution of these facies both in
space and time clearly marks the gradual invasion of the sea, and was used by
Hume as a means for classifying the Upper Cretaceous rocks of Egypt into five main
types from the north southwards. He suggested that folding towards the end of
Cretaceous times led to the formation of a series of parallel ridges rising from the
bottom of the Upper Cretaceous sea as islands or submarine ridges. Along these,
erosion took place, while deposition continued in the troughs in between ; hence
the existence of unconformities and disconformities between the Cretaceous and the
Tertiary systems along these ridges, and continuous depositon in the basins separa-
ting them. However, the controversy about the nature of the Cretaceous—Tertiary
boundary continued, and the vast concept of Zittel’s Danian was followed until the
use of Foraminifera modified the old beliefs and introduced new and revolutionary
concepts.

On the basis of small Foraminifera, Henson (1938) established two zones in the
Upper Cretaceous—Lower Tertiary succession of Palestine and adjoining countries
(including Egypt), a lower “‘ Globotruncana—Guembelina Zone ’’ of Upper Cretaceous
age, and an upper “ Globigerina—Globorotalia Zone, of transitional character between
the Cretaceous and the Tertiary. He regarded this transitional zone as extending
from the highest Danian into the early Eocene, and considered the junction between
these two zones as “‘ a reasonable approximation of the Cretaceous—Eocene contact ”’.
In other words, he considered the Globotruncana—Guembelina Zone to represent the
Danian (although the genus Globotruncana does not occur in the Danian) and the
Globigerina-Globorotalia Zone to represent the early Eocene, apparently including the
Paleocene. Moreover, he noticed that, even when there is no evidence of a break in
sedimentation between the Cretaceous and Eocene systems, the fauna of the trans-
itional zone is not equally developed in the various sections examined, and thus he
concluded that an imperceptible gap between the Cretaceous and Eocene systems
must exist.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 35

On the other hand, Faris (1947) described the Upper Cretaceous—Lower Tertiary
succession in the Taramsa—Tukh area, near Quena, in Upper Egypt, and echoed
Zittel (1883) in advocating the absolute conformity of the Cretaceous—Eocene
succession everywhere in Upper Egypt. He divided the Taramsa—Tukh section into
a lower, Cretaceous part and an upper, Eocene part, and divided the former into
Maestrichtian and Danian, but, failing to define the boundary between them, he
included both on his chart as Danian. He also considered his Eocene to include the
so-called “‘ Montian ? ”’ at its base and Londinian at its top ; but, while in the text he
considered his basal white limestone bed with G. cf. velascoensis as the top of his
Danian he included it on the chart at the base of the Eocene. However, analysis of
the succession as described by him shows that his Danian includes the Middle and
part of the Upper Maestrichtian, as well as most of the Paleocene. His “‘ Montian ? ”’
includes the uppermost Paleocene and the basal Eocene, while his Londinian repre-
sents the rest of the Lower Eocene. Moreover, a stratigraphical break between the
Maestrichtian and the Paleocene in his section is clearly evident (cf. the present
study), in spite of his repeated emphasis on the absolute conformity of the succession.

Tromp (1949, 1952), using his quantitative generic method in foraminiferal analysis,
noticed a number of micro-faunal differences between the uppermost Cretaceous and
the basal Eocene in Egypt, Turkey, and the Middle East in general. Nevertheless,
he considered the nature of the contact between these two systems to be gradational
and denied the existence of any indications of an erosional hiatus at the Cretaceous—
Eocene boundary in the Middle East. However, in agreement with Henson (1938),
he placed this boundary at the junction of the Globotruncana—Guembelina Zone with
the overlying Globigerina—Globorotalia Zone, although he considered the top of the
former zone to represent the top of the Maestrichian, not the Danian as previously
suggested by Henson (1938). Moreover, he stated (1949) that the Cretaceous—
Eocene boundary in the Middle East cuts through the so-called Danian and makes
the term superfluous. Asa result, he suggested that the term should be eliminated
at least in the Middle East, and added that “ Further evidence suggests that in other
countries also the term Danian is useless as an accurate stratigraphic unit and should
be abandoned’. He also mentioned that by using the quantitative generic method
in forminiferal analysis, he had been able to classify the Senonian of Egypt and of
Turkey into three stratigraphical units only, which he tentatively termed the
Santonian, Campanian and Maestrichtian.

Nakkady (1949, 1950, I9g51a, 1952, 1955) studied the Foraminifera of six Upper
Cretaceous—Lower Tertiary sections from widely separated areas in Egypt.
He concluded that the use of rock units as time-rock units (suggested by Zittel 1883
and adopted by later authors) was very misleading, and thus suggested dropping the
rock units and using bio-zones instead. Nakkady established three zones in the
Cretaceous-Tertiary transition period of Egypt, a lower Globotruncana Zone of
Maestrichtian age, an upper Globorotalia Zone of Paleocene age, and an intervening
Buffer zone, described as distinguished by the complete absence or extreme scarcity
of both Globorotalia and Globotruncana, which he assigned to the Danian, In

36 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

correlating these six widely spaced sections, Nakkady (19514, chart) showed the
existence of great differences in the thickness and the stratigraphical position of his
Buffer zone, and in the position of the upper limit of his Maestrichtian Globotruncana
Zone in the different sections studied. However, no attempt was made to explain
this marked variation, and instead of interpreting it in the obvious way, as a marked
stratigraphical break, Nakkady emphasized the conformity of the succession and
stated (1951a) that “ The chalk and the overlying Esna shales are two phases of
continuous sedimentation representing the last sequence of deposition at the close
of the Mesozoic and the advent of the Tertiary’. Moreover, he described the Esna
shale fauna as transitional in character, and thus followed Beadnell (1905) in regard-
ing the Esna shales as passage beds between the Cretaceous and the Eocene. Further-
more, despite the discovery of breaks between the Cretaceous and the Tertiary in
successions previously described as conformable throughout (e.g. Le Roy 1953),
Nakkady did not reconsider his statements. On the contrary, this author (1957,
1959) on one side, and Said & Kenawy (1956) and Said (1960) on the other, started a
lengthy argument on the so-called retardation in the appearance of Globorotalia
species in the various sections studied, and its different implications, but overlooked
the fact that this can be explained by the occurrence of breaks of varying magnitude
between the Cretaceous and the overlying Tertiary rocks.

Le Roy (1953) described the Upper Cretaceous—Lower Tertiary succession of the
Maqfi section, on the northeastern corner of the Farafra Oasis, Western Desert,
Egypt, and analysed its small foraminiferal fauna. He did not discuss the Nubia
variegated claystones and sandstones which constitute the basal part of the succes-
sion, but stated that they may probably be of pre-Maestrichtian age and may be
separated from the overlying chalk by an unconformity, interpreted by the abrupt
change in lithology between the two formations. Nevertheless, he recognized in the
overlying succession two major divisions demarcated by a minor lithological change
and a major palaeontological hiatus, a lower chalk unit of Upper Cretaceous (Mae-
strichtian) age, which he termed “ Unit A ”’ and an overlying succession of four rock
units (IV, III, II and I) of Lower Tertiary age. He recorded the abrupt faunal
change between “ Unit A” and “ Unit IV” which he interpreted as a probable
disconformity and stated that it could logically indicate the Mesozoic—Cainozoic
boundary.

Le Roy stressed the difficulty in assigning the Tertiary part of the succession to the
Paleocene or the Lower Eocene, and stated that “ Until the Egyptian Paleocene is
more specifically correlated in terms of the European section, the writer favours
allocating Unit IV to the basal Eocene ’’. However, comparison with the present
study proves this “‘ Unit IV” to be of Upper Paleocene age, and substantiates a
marked break between the Maestrichtian and the overlying Upper Paleocene. On
the other hand, Le Roy recorded a distinct erosional surface between his “ Unit 1V ”
and the overlying “‘ Unit III’, and a probable disconformity between the latter and
“Unit II”. This drove Nakkady (1957) to interpret ‘‘ Unit III”’ as a slipped
mass of the nummulitic limestone capping the succession. However, Le Roy

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 37

considered Units III and II as Lower Eocene, and added that although the age of
“Unit I’ is open to question, he tentatively assigns it to the Lower Eocene as well.

The same section was discussed by Nakkady (1957) ,where he interpreted Le Roy’s
Lower Tertiary units as representing the Danian, Montian, Thanetian and Ypresian,
advocating the conformity of the succession. On the other hand, Said & Kerdany
(1961) described the same succession, confirming Le Roy’s previous statement of a
major palaeontologic hiatus between the Creataceous and the Tertiary, and assigning
Le Roy’s Units IV, III and II to the Landenian and his Unit I to the Ypresian.
However, analysis of their recorded planktonic Foraminifera shows that their
Landenian includes both the uppermost Paleocene and the Lower Eocene. Globoro-
talia velascoensis which characterizes the Upper Paleocene and marks the Paleocene—
Lower Eocene boundary by the disappearance of its last survivors, was recorded by
Le Roy (1953) as characteristic of his Unit IV only, and its range was slightly
extended by Said & Kerdany (1961) to the basal part of Le Roy’s Unit II. Never-
theless, they included the whole of Unit II which was stated by them to have a
thickness of between 120 and 160 metres, together with the underlying Units III and
IV within the Landenian. Correlation with the Esna—Idfu sequence, shows clearly
that the part of this succession between the upper limit of G. velascoensis and the
base of the hard crystalline limestone (Le Roy’s Unit I) can be equated with the
“ Thebes calcareous shale member ”’ of the Esna—Idfu region, which is here considered
to be of Lower Eocene age.

Nakkady & Osman (1954) discussed the genus Globotruncana in Egypt and its
value in stratigraphical correlation, using Nakkady’s previous sections and two other
sections in western Sinai, the Qabeliat and the Sudr sections. Nevertheless, in
correlating the Campanian—Maestrichtian succession of these two relatively close
sections, the authors could not establish the same zones. Moreover, the record by
Nakkady & Osman of forms such as Globigerina pseudotriloba, G. quadrata, G.
cretacea var. esnehensis in Cretaceous strata is definitely erroneous, as these forms are
only known from the Tertiary. Similarly, their records of Globotruncana contusa,
G. caliciformis, G. aegyptiaca var. duwt and G. esnehensis in the Campanian, and forms
such as Globigerina cretacea d’Orbigny [ =Globotruncana cretacea (d’Orbigny)]| and its
synonym G. globigerinoides Brotzen, and Globigerinella aspera, in the Maestrichtian,
are very much doubted. The former species are restricted to the Maestrichtian,
while the latter are not known from this stage.

Youssef & Shinnawi (1954) described the succession in Wadi Sudr area, Western
Sinai, Egypt, where they showed the difficulty in sub-dividing the Senonian, the
Danian and the overlying Paleocene. Between the top of their Lower Senonian and
the base of their Lower Eocene, they described a succession (246-5 metres thick) of
limestones, chalky limestones and chalk with a thin shaly intercalation at its base
They regarded this succession as Campanian—Maestrichtian—Danian and partly
Paleocene, advocating the conformable relationship between the Cretaceous and the
Tertiary systems. They recorded some planktonic Foraminifera in their shaly bed
which they tentatively considered at the base of the Maestrichtian. Of particular

38 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

interest are Globotruncana arca (Cushman) and G. arca var. esnehensis Nakkady
(=G. esnehensis) and G. aegyptiaca Nakkady, an assemblage which indicates a
Maestrichtian age (probably Middle to Upper Maestrichtian). However, their
records of Globigerina cretacea d’Orbigny, G. linaperta Finlay and G. quadrata White
are erroneous ; the first, (which is a true Globotruncana, not a Globigerina) does not
extend above the Upper Campanian, the second is known from the Lower Eocene and
the third is definitely Paleocene. These forms were probably confused with apparently
similar Rugoglobigerina and Hedbergella species, but nothing can be added until the
planktonic Foraminifera of the succession are examined in detail.

Youssef (1954) described the succession in the Gebel Owaina section, as summarized
above, attributing it to the Maestrichtian, Danian, Paleocene and Lower Eocene,
and advocating the conformity of the succession. However, the present study
(see Text-fig. 4) shows that his Danian includes most of the Paleocene, and that his
Paleocene includes both the uppermost part of this series and the basal Eocene.
Moreover, it indicates a marked break between the Maestrichtian and the overlying
Paleocene, in spite of Youssef’s statement that the succession is apparently conform-
able throughout.

Said & Kenawy (1956) described the Foraminifera of the Upper Cretaceous—Lower
Tertiary succession of the Nekhl and the Giddi Sections, in northern Siani, Egypt.
Following Nakkady (1951a), they recognized in the two sections a lower unit of Maes-
trichtian age, characterized by the abundance of Globotruncana and Guembelina
species, a middle unit, of Danian age, characterized by the absence of Globotruncana
and by the presence of a flood of Globigerina together with certain other benthonic
forms, and an upper unit of Paleocene age, characterized, according to them, by the
appearance of various species of Tvuncorotalia and Globorotalia together with several
distinctive benthonic forms. They noted that the limits of these biozones are
independent of the lithological boundaries, a fact previously recognized by Nakkady
(1951a). They also followed Hume (1911) and Shukri (1954) in attributing the
varied nature of the Cretaceous—Tertiary boundary in geologically adjacent areas in
northern Egypt, to deposition over anticlines and synclines which had previously
emerged from the bottom of the Upper Cretaceous sea. These folds were attributed
to the Syrian arc movement which began at least as early as the Turonian, and which
was intermittently active until late Oligocene time. While erosion took place on the
anticlines, deposition continued in the adjacent troughs. With this idea in mind,
they tried to analyse the stratigraphical succession in the two sections, believing that
one of them, the Nekhl section, lay in the heart of a trough in the late Cretaceous sea,
while the other, the Giddi section, lay on the flank of one of the main structural highs
of that time. However, when the accepted index fossils for this period, the plank-
tonic Foraminifera, showed the incorrectness of this imaginary position of the two
sections, they tried to deprive these forms of their value in stratigraphical zonation
and world-wide correlation stating that “. . ..in Egypt. where the bottom topography
of the Upper Cretaceous-Lower Tertiary sea was affected by great lateral folding
movements, environmental conditions may differ from one place to another rather

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 39

rapidly, and this makes the use of planktonic species of rather limited value. The
only exceptions to this rule seems to be the Globotruncana and Giimbelina species,
which are assumed by many authors to have been planktonic’ and added “.... we
have abandoned the classic and oft-repeated zoning based on the planktonic foramini-
fera Globigerina and Truncorotalia. We feel that these forms are facies fossils,
which, may have some zoning value but which occur, like their descendants in modern
times, only in open and moderately deep seas’. Thus, while at the beginning of their
work they followed Nakkady’s zonation of the Upper Cretaceous—Lower Tertiary rocks
of Egypt into a Globotruncana—Guembelina Zone of Maestrichtian age, a Globigerina
or Buffer Zone of Danian age, and a Globorotalia Zone of Paleocene age, they used
Bolivinoides and Neoflabellina for the classification of the succession, and thus confused
the correlation between the two sections. Without discussing the disadvantages
and mistakes of such a classification (e.g. their record of Neoflabellina rugosa, a
known Campanian form, in their Upper Maestrichtian, Danian and Paleocene),
these authors stated that “‘ These species are, unfortunately, rare in the Egyptian
material and may escape notice’’. However, other than the undisputed value of
Globorotalia in Lower Tertiary stratigraphy and correlation, the fallacy of the whole
picture presented by Said & Kenawy (1956) is clearly demonstrated by their text-
fig. 4. In this text-figure, the parallelism between their Globotruncana time surface
and their Tvwncorotalia surface, indicates that the folding movement which shaped
the strata of the two sections in their present day form, definitely took place after
the appearance of the sharply-keeled globorotalias, i.e. at least after the beginning
of the Upper Paleocene and not before the deposition of the Maestrichtian as suggest-
ed by these authors. Indeed, a similar folding movement which affected the Upper
Cretaceous—Lower Tertiary rocks of the Esna—Idfu region is of post-Lower Eocene
age. Nevertheless, this does not deny the possibility that the Upper Cretaceous
sea bottom was affected in certain regions by intermittent folding movements
(which might even have started long before the Upper Cretaceous), as suggested by
Hume (1911) and Shukri (1954), and substantiated by deep drilling in the northern
part of the Western Desert (see Said 1962). One of the most striking contradictions
in Said & Kenawy’s discussion is their statement that ‘“‘ The Maestrichtian—Danian
boundary is therefore of importance in determining the structural position of the
locality from which a section was taken. When this boundary coincides with the
lithologic boundary between the chalk and the Esna shale, it indicates a structural
low, whereas its occurrence within the Esna shale indicates a structural high in the
late Cretaceous sea. This idea is further strengthened by the fact that we find the
thinnest Danian, followed immediately by the Tvuncorotalia zone, in the structurally
low areas’’. Contrary to this conclusion, the present study has shown that the
variation in the thickness of the Danian strata, which are generally of the same
lithological composition, is mainly due to the occurrence of stratigraphical breaks of
varying magnitude between the Maestrichtian and the overlying Paleocene, and that
the thinnest Danian occurs in areas which were subjected to more uplift and/or more
erosion, not in the structually low areas, as suggested by these authors. On the
other hand, correlation with the succession in the Esna—Idfu region shows clearly

40 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

that their Lower Eocene of the Giddi section is partly of Upper Paleocene age, that
their Upper Paleocene of the Nekhl section is definitely Lower Eocene, and that the
presence of the Danian in the two sections is to be doubted because of the absence of
typical Danian forms such as Globorotalia compressa (Plummer), G. pseudobulloides
(Plummer) G. tvinidadensis Bolli and Globigerina daubjergensis Bronnimann. More-
over, it points to the occurrence of a stratigraphical break between the Maestrichtian
and the overlying paleocene, substantiated by the reduced thickness of the shale
succession between the top of the Maestrichtian and the first appearance of G.
velascoensis, especially in the Nekhl section (although their G. velascoensis is mis-
identified).

Hassan (1956) studied the type area of Zittel’s “‘ overwegischichten’”’ in the
Kharga Oasis, which he considered to be of Maestrichtian age, and divided it into
the following three faunal zones :

‘

1. A lower zone (A) with Jsocardia chargensis, Bostrychoceras polyplocum,
Nostoceras sp., Nautilus desertorum, Baculites anceps, Chlamys mayereymart
and Trignoarca cf. gauldrina.

2. A middle zone (B) with Exogyra overwegi, Plicatula instabilis, Plicatula
aschersom, Veniella (Roudaireia) dru, Cardita libyca and Hoplitoplacenti-
ceras awadt.

3. An upper zone (C) with Cardita libyca and no ammonites.

He followed Laffitte (1934, 1939) in considering the lower limit of the Maestrichtian
in North Africa to be marked by the appearance of Orbitoides tissott, Bostrychoceras
polyplocum and Libycoceras ismaéli and thus considered his zone (A) to be of Lower
Maestrichtian age. However, as mentioned by Leriche (1927, 1929), Abrard (1931,
1948) and Jeletzky (1951), Bostrychoceras polyplocum characterizes the Upper
Campanian in its type area, and Hassan’s zone (A) should therefore belong to the
Upper Campanian and not the Lower Maestrichtian, if his record of Bostrychoceras
polyplocum is correct.

In his zone (C), Hassan stated that ‘‘ Not a single ammonite has been found in the
third zone which is crowded with Cardita libyca’’. Nevertheless, he assigned this
zone to the Upper Maestrichtian, although in the same paper he mentioned that
Fourtau (1904) had clearly reasoned that the limit between the Maestrichtian and
the Danian should be drawn at the top of the highest bed with ammonites in the
Libyan Desert.

Nakkady (1959) described the same section and assigned the lower part of the
succession to the Maestrichtian, the Cardita beds and the overlying shale and chalk
section to the Danian and the nummulitic limestone above, to the Montian. However,
analysis of his recorded planktonic Foraminifera shows that his Danian actually
represents the whole Paleocene, while his Montian represents the Lower Eocene.
Moreover, a comparison of the succession, as described by both Hassan (1956) and
Nakkady (1959), with the sections studied, clearly points to the occurrence of a
marked stratigraphical break, in spite of the fact that these authors described the
succession as perfectly conformable.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 41

Nakkady (1957) reviewed the biostratigraphy of the Upper Senonian and the
Paleocene of Egypt, which he tried to correlate with corresponding units in other
parts of the world. He considered the Senonian to include the Coniacian and the
Santonian as its lower part, and the Campanian and the Maestrichtian as its upper,
and divided the Paleocene into a lower part including the Danian and the Montian,
and an upper including the Thanetian and Sparnacian. However, although he
only discussed what he described as Campanian, Maestrichtian, Danian and Montian,
analysis of his faunal lists shows that his Montian actually represents the Lower
Eocene and his Danian, the whole Paleocene. Moreover, comparison of the eight
sections correlated by him (Text-fig. 2) with the succession in the Esna—Idfu region,
indicates a marked break between the Upper Cretaceous and the overlying Tertiary
rocks in each of the described sections, despite the fact that he strongly advocated
the conformity of the whole succession.

Youssef (1957) described the Upper Cretaceous—Lower Tertiary succession in the
Kosseir area, recognizing the following four formations from the base upwards :
the Nubia sandstone, the Kosseir variegated shales, the Duwi formation and the
Esna shales. He included the first three formations within the Campanian (although
he considered the top part of the last formation to be of basal Maestrichtian age), and
regarded the Esna shales as representing most of the Maestrichtian, the Danian (or
Dano-Montian) and the Paleocene. He did not discuss the stratigraphical position
of the overlying limestone beds, but included them on his columnar section within
the Paleocene, and considered the succession to be conformable throughout. He
mentioned the difficulty in establishing the lower and upper limits of the Maestrich-
tian, but following Laffitte (1939) he considered the base of this stage to be marked
by the appearance of Libycoceras ismaéli Zittel and its associated fauna, which is here
considered to be of Upper Campanian age. The succession compares well with that
of the Esna—Idfu region, although the phosphate formation is much more developed
in the Kossier area. Correlation of the two sections shows that the base of Youssef’s
Maestrichtian should be included in the Upper Campanian, and the Maestrichtian—
Danian boundary should cut somewhere through the 105 metres thick shale bed
considered by him to lie at the base of the Danian. This shale bed actually includes
the top of the Maestrichtian and most of the Paleocene. Moreover, it is felt, by
comparison with the succession in the Esna—Idfu region, that a careful examination
of the above-mentioned shale bed may prove the existence of a stratigraphical
break marking the Mesozoic—Cainozoic boundary, despite Youssef’s emphasis on the
conformity of the succession.

Faris & Hassan (1959) described the Upper Cretaceous—Lower Tertiary succession
of the Um-E]-Huetat section, Safaga area, Red Sea coast, which they divided into
seven successive units. They considered the lowest two units (I and II) as Lower
Senonian and even older, Unit III as Santonian to Campanian, Units IV and V as
Lower and Upper Maestrichtian respectively, Unit VI as Danian to Paleocene and
Unit VII as Lower Libyan. However, analysis of the succession as summarized by
them shows that the upper part of their Unit VI which they collectively described as
“Danian to Paleocene ’’, is of Lower Eocene age. The “‘ Eponides lotus fauna ”

42 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

which was described by Le Roy from the Maqfi section and with which they correlated
this part of their succession, is of Lower Eocene age (see p. 37). Again, their
description of the underlying zone as characterized by Aturia cf. praeziczac is very
misleading, as the latter species characterizes, in the Luxor section, an horizon
equivalent to the “ Eponides lotus fauna ’’ of the Maqfi section. Moreover, in spite
of a marked break in the succession, and the absence of the Lower and Middle
Paleocene in the Maqfi section, Eponides lotus was found to appear at a vertical
distance of about 120 metres from the underlying Maestrichtian surface, while they
recorded this species in a lithologically identical succession, at a vertical distance of
only 70m. from the top of their Maestrichtian, and advocated the conformity of the
succession throughout. However, until the succession is more carefully examined,
nothing much can be added, although the Foraminifera of two samples from the
Maestrichtian part of the succession (described by Ansary & Fakhr 1958), included
some rare planktonic forms. Nevertheless, a probable stratigraphical break between
the Maestrichtian and the overlying Paleocene is indicated by the marked reduction
in the thickness of the strata assigned to the latter series.

Said (1960) recorded fourteen species of planktonic Foraminifera from what he
described as Esna shale and the overlying Thebes formation of the Gebel Gurnah
section, at Thebes (on the western bank of the Nile, facing Luxor). He concluded
that the ‘“‘ Esna shale ”’ is Landenian in age while the Thebes limestone is Ypresian.
Analysis of his described planktonic Foraminifera, and comparison with the present
study shows that both the shales and the limestones are of Lower Eocene age. It
also indicates that the shaly part of the succession is equivalent to the ‘‘ Thebes
calcareous shale member ”’ of the Gebel Owaina section, which is here equated with
the Globorotalia wilcoxensis Zone of earliest Eocene age. This throws doubt on the
validity of the identification of forms recorded by Said, e.g. G. velascoensis (Cushman),
G. imitata (Subbotina), G. conicotruncata (Subbotina) and Globigerina triloculinoides
Plummer, which are restricted to the Paleocene. However, the possibility that the
basal I—5 metres of the succession may be of uppermost Paleocene age is not
excluded. Indeed comparison of his figures and descriptions with the original
descriptions and figures of the above-mentioned species, and with the specimens
described in the present study shows that his forms need to be renamed and re-
described in more detail.

Hermina, Ghobrial & Issawi (1961) described the Upper Cretaceous—Lower
Tertiary succession of the Dakhla Oasis, Western Desert, Egypt, and in disagreement
with Zittel (1883) and Beadnell (1901), they recorded a marked break between the
Maestrichtian and the overlying Danian in most of their measured sections. How-
ever, they noticed that the gap represented by this break is gradually minimized
westwards where they stated that “...a monotonous shale section follows above
the uppermost zone of the Upper Maestrichtian with possible conformable relation-
ship ”’.

These authors considered the unfossiliferous Nubia formation to be of uppermost
Campanian or Lower Maestrichtian age (being conformably overlain by rocks they

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 43

regarded as of Lower Maestrichtian age), and classified the overlying strata as
Maestrichtian, Danian, Paleocene and Lower Eocene. Moreover, they divided both
their Maestrichtian and Danian into lower, middle and upper units, and their
Paleocene into Lower and Upper Paleocene. However, it is evident from their
description that their divisions were very tentative and hardly based on any correl-
ation with the type or corresponding sections in other parts of the world. Neverthe-
less, comparison with the succession in the Esna—Idfu region showed that :

1. Their Lower Maestrichtian should be assigned to the Upper Campanian, as
both the Bostrychoceras polyplocum and the Inoceramus regularis faunal
assemblages with which they tried to equate their Lower Maestrichtian,
are of Upper Campanian age (see “‘ General Discussion ’’ above).

2. Their Middle and Upper Maestrichtian, probably represent the most complete
Maestrichtian section as yet known in southern Egypt. The upper zone
of their Upper Maestrichtian which they distinguished by the presence of
Trigonoarca gauldrina and Cardita dakhlensis, is missing in the Esna—Idfu
region and was reported by them to be missing from most of their measured
sections.

3. Inspite of the above-mentioned fact, their statement of a possible conformable
relationship between the Cretaceous and the Tertiary systems in the western
part of the Oasis, still needs further support. Their only argument is the
existence of a zone with Globigerina spp. and no Globorotalia of the compressa
group on top of the Maestrichtian Globotruncana zone. Yet, the same zone is
recorded at the base of the type Danian, where a physical break in the
succession and a major faunal break are documented.

4. Both their Danian and Paleocene are extremely difficult to correlate, although
their Ostrea hypoptera Zone which they regarded as Upper Danian, corresponds
in the present study to most of the G. velascoensis Zone which represents
the Upper Paleocene. If this is the case, their Danian should be regarded
as representing most of the Paleocene, and the Paleocene-Lower Eocene
boundary should cut through their Upper Paleocene. However, a
detailed study of the planktonic Foraminifera of this succession is needed to
establish a proper correlation, and to reveal the missing zones in the
previously described Cretaceous—Tertiary sections.

This rapid review of the most important Upper Cretaceous—Lower Tertiary sections
in Egypt summarizes the nature, classification and distribution of these rocks and
their varied interpretation by different authors. It also shows the difficulties
encountered in the stratigraphical analysis of these strata, and the several problems
which were left unsolved. Comparison with the succession in the Esna—Idfu region
shows clearly that the boundary between the Campanian and the Maestrichtian
could not be decided, that the Maestrichtian could not be defined or classified, that
the Mesozoic—Cainozoic boundary could not be traced, that the Danian could not be
clearly defined, that the various divisions of the Paleocene were very much confused,

44 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

and that the Paleocene—Eocene boundary was differently interpreted by different
authors.

C. SUMMARY OF THE SUCCESSION

The Upper Cretaceous—Lower Tertiary succession in the Esna~—Idfu region is
naturally divided into four main lithological units which are easily recognizable in the
field and are arranged from the base upwards as follows :

1. A lower arenaceous unit composed mainly of sandstones, and passing into
variegated shales at its top through various intercalations of shaly sand-
stones, sandy shales, shales and clays. The base of this unit is nowhere
visible in the region, but can be seen unconformably overlying the basement
complex at a distance of about 75 kms. to the east and about 100 kms. to the
south. This unit is about 500 m. thick, but a maximum thickness of 80 m.
only crops out in the-Esna—Idfu region.

2. An alternating succession of broadly extended phosphate lenses (approaching
the form of regular beds), marl with flint nodules, chert bands and oyster
limestone, which has a maximum thickness of about Io m.

3. Alutaceous unit about 240m. thick, composed mainly of shales, but with marly
and chalky intercalations.

4. An upper calcareous unit composed of a small thickness of calcareous shales at
its base, passing upwards into chalky, marly and siliceous limestones which
constitute the main part of this unit. Only the basal 60 m. or so crop out in
the Esna—Idfu region, while to the north and west the unit reaches a thick-
ness of about 340 m.

The lowermost sandstone unit, which was commonly referred to as “‘ the Nubian
sandstone ’’ was recognized by Youssef (1957), in the Kosseir area, as a formation and
was named the “ Nubia sandstone ”’.

Ghorab (1956) considered the variegated shales overlying the Nubia sandstone and
underlying the lowermost phosphate bed in the Kosseir area as a separate formation
and named it the “‘ Quseirformation’’. Youssef (1957) suggested the name “ Kossier
variegated shales’ for the same formation. However, because of the small thickness
outcropping of both the sandstones and the shales in the Esna—Idfu region, and because
the two facies pass imperceptibly into one another, these variegated shales are here
included within the Nubia sandstone, and the two facies are considered as one forma-
tion which is here collectively termed “‘ the Nubia sandstone and variegated shale ”’.

A succession of phosphates, marls and limestones overlies the Nubia sandstone and
variegated shale, with a general conformable relationship, except for local thinning
out, diastems or even disconformities. This succession, although of a comparatively
small thickness (not exceeding 10 m.), has a considerable lateral extent, and forms a
sharply distinctive and a conveniently mappable rock unit. Thus it is here consider-
ed as a distinct formation and assigned the name “ Sibaiya phosphate’”’. Ghorab

LITHOSTRATIGRAPHICAL UNITS BIOSTRATIGRAPHICAL UNITS AGE
PLANKTONIC FORAMINIFERAL UNITS MACROFAUNAL UNITS “ a Pa
2
GROUP} FORMATIONS AND MEMBERS 2 EE
ASSEMBLAGES ZONES AND SUBZONES ASSEMBLAGES) ZONES AND SUBZONES 3 NE ee
L
t VERY RARE PLANKTONIC FORAMINIFERA ; ; Ta
oa THEBES LIMESTONE THEBES LIMESTONE Lucina thebaica ~~ Zone
iI5 {Flood of Nummulites Operculina, — Assilina, Discocyclina, etc.) “ay
> re) AND as es = Fs
= ie CALCAREOUS HIGHLY RUGOSE GLOBIGERINA / (CREWE BTN 2s
SHALE THEBES CALCAREOUS SHALE | HIGHLY RUGOSE AND/OR KEELEO Globorotalia wilcoxensis Zone =z
CLOBOROTALIA x0 Zone with no macrofauno %
(except for rare dwarfed forms) xf
UPPER OWAINA SHALE Globorotalia equa / AMMONITES = SS
GLOBIGERINA / SHARPLY ~ KEELEO Globorotatia,velascoensis | Gioborotalio esnaensis = =
ao S |= |/a
GLOBOROTALIA Zone Subzone = ay
2 OWAINA SHALE MIDDLE OWAINA CHALK 2/3 /w
(e) Globorotalia pseudomenardii Subzone| Gslrea hypoplera gene IL Sie
o EAT aE GLOBIGERINA / TRUNCATED GLOBOROTALIA | Globorotalia ongulata Zone _fejeeoretsve Bustle“ Subrone— fr HEERSIAN| =
GLOBIGERINA / ROUNDED GLOBOROTALIA Glaborotalia. compressa, /) Globigerina davbjergensis Zone Easyosm lay socanesala yazan Oia | DANIAN
g UPPER SHARAWNA SHALE GLOBOTRUNCANA /, Globotruncona esnehensis Zone Libycoceras berisensis Subzone
n RUGOG LOBIGERINA/ Pecten (Chlamys) 5 =
us SHARAWNA SHALE | MIDDLE SHARAWNA MARL ABATHOMPHALUS / Globotruncana gansseri_ Zone mayereymari Pecten(C) mayereyman Subzone | 3 Ss
= =
HEOBEROELLA WHEN OUTER Tone =| &
LOWER SHARAWNA SHALE Globotruncana fornicota Zone Terebratulina gracilis Subzone} = =
BACULITES =
=
a ASSEMBLAGE = 2/3
3 SIBAIYA PHOSPHATE VERY RARE PLANKTONIC FORAMINIFERA Lopha ville Zone = S ©)
x =
0) > 2
= <
| = le
< 2 Ela
a e=| =
> NUBIA SANDSTONE AND Zone! with) no) (macrafauna = = 2 &
Zz NO FORAMINIFERA 2:
VARIEGATED SHALE (excep! for rare plont and vertebrate remains ) 2 3S
z=
{ IL = Ly Ly it

7 5.

Summary of the various Litho- and Biostrat

shical units of the Upper Cretaceous—Lower Tertiary succ

on in the Esna-Idfu Region.

; 5 = 5 oe a}

<=
ee
oO st ~ -
{ en

>

21 PAD STI AACAH AAA RIAA Te

oo Vit > WITS
2R28MaoM-Ghir..2cHOMTAMAGS
; ) PONE.
. ae ee) er
) mn ‘ u Ear
Is a
AAUING :
i bikue

Ta Mea 1A {3 , AMLAWO-

ai ARLD
At -

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 45

(1956) considered similar phosphate deposits in Kosseir area as a formation and
named it~“ the Duwi formation’”’, nevertheless the present phosphate deposits
cannot be assigned to the same formation, as they are comparatively much reduced in
thickness. The “ Sibaiya phosphate ’”’ either represents a dwarfed ‘‘ Duwi forma-
tion ’”’ or only corresponds to a part of that formation. Until the two formations are

precisely correlated, it is advisable to treat them separately.

The thick shale succession, which conformably overlies the Sibaiya phosphate
formation, and which is conmmoly referred to as the “‘ Esna shales ’’, was recognized
by Ghorab (1956) as a formation which he named the “ Esna formation ”’ and divided
into three main members from the base upwards as follows : the “ Dakhla ash-grey
shale member’’, the “‘snow-white Ananchytes ovata chalk member’’, and the
“ Kharga paper shale member ’’. However, the present study shows that this thick
shale succession is actually a group of rock units naturally divided into two distinct
formations separated by a marked break and a well developed conglomerate. The
lower formation is here named “ the Sharawna shale ’’, with its type section in the
Wadi El-Sharawna area, it has a thickness of about 120 m., and is proved to be of
Maestrichtian age. It includes three main members, a lower shale, a middle marl and
an upper shale member, the top part of which is truncated by a disconformity.

,

The upper formation is here named “‘ the Owaina shale ’’, with its type section in
Gebel Owaina, it also has a thickness of about 120 m. and is proved to be of Paleocene
age ; it includes two shale members separated by a middle chalk member. Its lower
limit is marked by the disconformity and its upper underlies the “‘ Thebes calcareous
shale ’’.

The uppermost succession of calcerous shale, shaly limestone, and limestone is here
assigned to the ‘“‘ Thebes formation’’. However, the lower calcareous shale is
distinguished from the overlying ‘“‘ Thebes limestone ” as a separate member of the
same formation and is given the name “ Thebes calcareous shale ”’ although it has
been wrongly assigned by various authors to the Esna shale.

These different rock units are summarized in Text-figs. 5 and 8, their fossil content
is listed in Text-figs. 16 and 17 and their respective ages are discussed below. The
detailed lithostratigraphy of the succession and the lateral variation in the various
rock units are discussed elsewhere (El-Naggar 7m manu.), and the main sections
examined are correlated in Text-fig. 7.

D. DISCUSSION OF THE AGE

(1) THE NuBIA SANDSTONE AND VARIEGATED SHALE FORMATION

The Nubia sandstone and variegated shale could not be assigned a definite age
because of its scanty fossil content. However, as the formation is conformably over-
lain (in places) by the Sibaiya phosphate formation which is here considered as
Upper Campanian, and as the upper part of the Nubia formation contains rare
vertebrate remains which are identical to those of the overlying Sibaiya formation,
this upper part, at least, should be regarded as only slightly older than the overlying

46 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

“ Sibaiya formation ’’.8 Moreover, as no stratigraphical breaks were observed within
the part of this formation, outcropping in the Esna—Idfu region, the author is
inclined to include the outcropping part of the Nubia formation in the Esna—Idfu
region, in the Campanian. However, as there is no direct evidence, the age of this
formation is here considered to be Campanian and ? pre-Campanian.

(2) THE SIBATYA PHOSPHATE FORMATION

Despite the fact that the Sibaiya formation did not yield any identifiable plank-
tonic Foraminifera, and that its macrofauna does not provide a direct means for
correlation with the type sections in Europe, it is here considered to belong to the
Upper Campanian for the following reasons :

(a) Blanckenhorn (1921) and Hassan (1956) recorded Bostrychoceras polyplocum
Roemer, an index fossil for the Upper Campanian in its type section and
elsewhere, from the same formation in other parts of Egypt, and with a
typically similar association of fauna.

(b) The Sibaiya formation is conformably overlain by the “‘ lower Sharawna shale
member ”’, which is characterized by the first appearance of Terebratulina
gracilis Schlotheim, an index fossil for the base of the Maestrichtian.
Terebratulina gracilis was also recorded from Lower Maestrichtian strata

conformably overlying the “‘ Bosytrchoceras polyplocum s.l. Zone ”’ in Germany
(Schmid, Hiltermann & Koch 1955) ; in Palestine (Parnes 1956) ; in Holland,
Belgium and in the Aquitaine Basin of France (Upper Cretaceous Stratigraphic
Commission, International Geological Congress ; 7m Reiss 1962 : 4).

(c) Most of the recorded Pelecypod fauna was considered by the various authors
(including Coquand, the creator of the Campanian substage) to be mainly of
Campanian age, although a few forms may continue into the overlying basal
Maestrichtian. On the other hand, the varied vertebrate fauna of the
Sibaiya phosphate formation occurs in Europe in strata of Coniacian to
Campanian age (e.g. Siegfried 1954, 1956).

(d) The Sibaiya formation is conformably overlain by two successive planktonic
foraminiferal zones which are considered, by correlation with similar zones
in other parts of the world (Text-figs. 5, 6), to represent the Lower and
Middle Maestrichtian respectively.

(e) In spite of its small thickness, the Sibaiya formation, as a chemically formed
deposit, represents a relatively long period of time and an enviroment of
deposition, completely different from that of the overlying shales.

(f) The Sibaiya phosphate formation can be correlated with similar deposits
in the Kharga and Dakhla Oases, Oift and Quene areas, Kosseir and Safaga
districts and with corresponding deposits in the Middle East and North
Africa which are regarded as Upper Campanian.

* The close similarity of the vertebrate remains in these two formations suggested their inclusion in

one group of rock units, here termed the ‘‘ Nubia group’”’, and is discussed elsewhere (El-Naggar,
in manu.).

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 47

(3) THE SHARAWNA SHALE FORMATION.

The Sharawna shale formation is considered to be of Maestrichtian age for the
following reasons :

(a) It conformably overlies the Upper Campanian “ Sibaiya phosphate forma-
fom,.”*.

(b) Eleven meters above the base of the formation, a marly band flooded with
Terebratulina gracilis Schlotheim, Isocardia (Isocardia) chargehensis Mayer-
Eymar and Pecten (Chlamys) mayereymart Bullen-Newton, as well as with
several other macro- and microfossils, was discovered. Tevebratulina
gracilis marks the base of the type Maestrichtian in Holland, and of the
Maestrichtian rocks in Belgium and in the Aquitain Basin of France (the
Maestricht-Committee of the Sub-Committee on the Upper Cretaceous
Stratigraphic Commission, International Geological Congress ; in Reiss
1962). It also marks the base of the Maestrichtian in Germany (Schmid,
Hiltermann & Koch 1955) and in Palestine (Parnes 1956).

(c) The lower part of the Sharawna shale formation i.e. the Lower Sharawna
shale member, is flooded with a rich planktonic foraminiferal fauna
(Text-figs. g-11, 16) which substantiates its Lower Maestrichtian age and
correlates it with the Lower Maestrichtian in various parts of the world
(Text-fig. 6).

This fauna characterises a particular zone which is here termed the Globotruncana
fornicata Zone. Noteworthy among the species characteristic of this zone are
members of the Globotruncana fornicata group and most of the members of the
Globotruncana stuarti group, the last representatives of which mark the Lower
Maestrichtian in most parts of the world. (e.g. Cita 1948 ; Tilev 1951, 1952 ;
Drooger 1951 ; Bolli 1951, 1957a@ ; Noth 1951 ; Sigal 1952 ; Dalbiez 1955 ; Gandolfi
1955 ; Pozaryski & Witwicka 1956 ; Bronnimann & Brown 1956 ; and Pessagno
1960).

Also of importance in this zone are : Globotruncana arca, G. gagnebint, G. fareedt,
G. havanensis and Rugoglobigerina rugosa, which are known to be restricted to the
Maestrichtian in different parts of the world (see Bronnimann & Brown 1956 ;
Tilev 1951, 1952 ; Bolli 1957a ; Berggren 1962, etc.), as well as Globotruncana
leupoldi, G. aegyptiaca aegyptiaca, G. tricarinata tricarinata and G. ventricosa, which
characterize older strata, but range through the Lower Maestrichtian.

(d) The “ Middle Sharawna marl member ”’ is marked by the first appearance of
Globotruncana ganssert ganserrt Bolli at its base, and this, together with
its other subspecies, floods the whole unit and the lower part of the overlying
shale member, constituting a particular faunal zone, here termed the “‘ Globo-
truncana ganssert zone’’. Analysis of the stratigraphical ranges of the
various members of this zone, substantiates its Middle Maestrichtian age
and correlates it with corresponding strata elsewhere. Globotruncana
ganssert ganssert Bolli, the index fossil of the zone, was recorded as

48 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

flooding the Middle Maestrichtian of various parts of the world, with rare
occurrence in the upper part of the Lower Maestrichtian and in the basal
part of the Upper Maestrichtian (Bolli 1951, 1957a, 1959b ; Nakkady &
Osman 1954 ; Gandolfi 1955 ; Dalbiez 1955 ; Bronnimann & Brown 1956 ;
Olsson 1960 ; Pessango 1960 ; and Berggren 1962). This zone is also
flooded with forms of definite Maestrichtian age such as Globotruncana
contusa contusa, G. contusa patelliformis, G. arca, G. conica, G. esnehensis,
G. fareedi, G. gagnebini, G. lugeont, G. stuarti parva, G. aegyptiaca aegyptiaca,
G. aegyptiaca duwi, G. havanensis, Abathomphalus intermedia, Rugoglobi-
gerina rugosa, R. pustulata, R. penny, R. macrocephala, R. loetterli, R.
glaessnert, Hedbergella monmouthensis, H. petaloidea, H. matison, H. hessi
hessi and H. hessi compressiformis.

Some of these species were recorded from the type Maestrichtian (Hofker
1962a), from the Maestrichtian rocks underlying the type Danian (Troelsen
1955 ; Berggren 1962) and from the Maestrichtian rocks of various parts of
the world. (See the discussion under each of the above-mentioned species.)

(e) The Upper Sharawna shale member conformably overlies the “ Middle
Sharawna marl member ’’, while its top is truncated by a marked strati-
graphical break. A conglomerate with reworked Maestrichtian ammonites,
gastropods and lamellibranchs, together with a typical Upper Danian
fauna, marks this break and indicates the dawn of the Cainozoic era.

ce

Analysis of the planktonic foraminiferal content of the ““ Upper Sharawna shale
member ”’ has proved its Middle to Upper Maestrichtian age. It has also proved
that its lower part constitutes the top of the Middle Maestrichtian G. ganssevi zone,
while its upper part constitutes the lower part of the Upper Maestrichtian G. esnehen-
sis zone. Worthy of mention in the latter zone are the following species :

Abathomphalus mayaroensis, A. intermedia, Globotruncana contusa contusa, G.
contusa patellifornis, G. esnehensis, G. gagnebim, G. aegyptiaca aegyptiaca, G.
aegyptiaca duwi, G. maniei, G. havanensis, G. stuarti parva, Rugoglobigerina rugosa,
R. rotundata, R. pustulata, R. pennyt, R. macrocephala, Trimitella scotti, Hedbergella
monmouthensis, and H. petaloidea. These were partly recorded from the Upper Maes-
trichtian at its type section (Hofker 1962a), from the Upper Maestrichtian rocks below
the type Danian (Berggren 1962 and Troelsen 1955), and from the same horizon
elsewhere (Brénnimann 1952a ; Bronnimann & Brown 1956 ; Bolli 1951, 19574,
19590 ; Dalbiez 1955 ; Pessango 1960, 1962, etc.). However, the fact that in the
succession studied, the Upper Maestrichtian part is represented by a comparatively
small thickness of strata (about 13 m. only), and that reworked Upper Maestrichtian
macrofossils occur in the conglomeratic band which forms the base of the Upper
Danian strata above, clearly indicates that the uppermost Maestrichtian is missing.
Thus the upper part of the ‘‘ Upper Sharawna shale member ”’ corresponds to the
lower part of the Upper Maestrichtian only.

The macrofauna of the Sharawna shale formation correlates it with equivalent
Maestrichtian strata in Egypt, the Middle East and North Africa (Parnes 1956 ;

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 49

Hassan 1956 ; Youssef 1957 ; Hermina, Ghobrial & Issawi 1961). Its planktonic
Foraminifera correlate it with the type Maestrichtian (Hofker 1962a), with the
Maestrichtian rocks below the type Danian (Berggren 1962 and Troelsen 1955) and
with the Maestrichtian in various parts of the world (Text-fig. 6). However, the
disconformity separating the Maestrichtian Sharawna shale formation from the
overlying Paleocene was always overlooked in the past, and the stratigraphical
sequence as well as the chronological succession of life in this part of the geological
column was never completely understood. As a result, various authors (e.g. Hume
IgI1, 1912, followed by most stratigraphers) tended to lump the Sharawna shale
formation, either partly or completely, together with the overlying Lower Owaina
shale member under the term “‘ Lower Esna shales ’’, and considered these shales
with the overlying chalk bed as of Danian age. On the other hand, Nakkady (1959)
described as “‘ Lower Esna shale’ in the Kharga Oasis, a succession of Paleocene
shales which is here considered to be identical with the Lower Owaina shale
member.

Thus, it is evident that the classification of the Esna shale into lower and upper
units as suggested by Hume (1911, 1912) and followed by various authors is incorrect,
and should be replaced by the classification suggested here. Again, it is worth
noting that the term Dakhla shale, introduced by Ghorab (1956) as a member of his
Esna formation, to substitute for the ““ Ashen grey paper shales ”’ of some authors,
or the “‘ Lower Esna shale ”’ of others, and which was raised to formational rank by
Said (1961) is also incorrect. The “ Dakhla shale”’ as originally designated and
interpreted in the present study, includes the Maestrichtian ‘‘ Sharawna shale ’’, the
conglomerate separating it from the overlying Paleocene “‘ Owaina shale’, and the
lower part of the latter formation. These varied lithological and palaeontological
units which are clearly separated by a marked break, cannot be treated as one
formation. Thus the term ‘“‘ Dakhla shale’ is here dropped and the classification
of the Esna group into a lower “‘ Sharawna shale ”’ formation and an upper “ Owaina
shale ’’ formation is suggested.

The “ Sharawna shale’ is equated on lithological and palaeontological grounds
with similar successions in both the Dakhla and the Kharga Oases (Western Desert)
and in the Kosseir and Safaga areas (Red Sea Coast). It is proved to have a wide
geographical extent in Egypt, although it becomes gradually more calcareous when
followed northwards until completely replaced by chalk.

(4) THE OwaINA SHALE FORMATION.

This formation is considered to be of Paleocene age, for the following reasons:

(a) It, disconformably overlies the Maestrichtian ‘‘Sharawna shale”, and
underlies the Lower Eocene “‘ Thebes formation ’’.

(b) Its base is marked by a conglomerate with reworked Maestrichtian, and
Danian faunas, and its upper part coincides with the top of the Globorotalia
velascoensis Zone which is taken to mark the end of the Paleocene in vari-
ous parts of the world (see Text-fig. 6).

50 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

(c) Its basal part contains a rich fauna of the Globorotalia compressa/Globigerina
daubjergensis Zone which correlates it with the type Danian (Brénnimann
1953 ; Reichel 1953 ; Troelsen 1957 ; Loeblich & Tappan 1957a, b ; and
Berggren 19600, 1962) and with the Danian elsewhere (Bolli 1957), 1959);
Loeblich & Tappan 1957a, 6b ; Bolli & Cita 1960a, b ; Olsson 1960 ; Hay
1960 ; Leonov & Alimarina 1961).

The abundance of Globorotalia compressa (Plummer) in the Danian part
of this succession, which is very much reduced in thickness (maximum of
about 17 m. only), clearly proves that it represents the Upper Danian only
(see Berggren 1960b, 1962), and that both the Lower and Middle Danian are
missing.

(d) This Upper Danian part is followed by a zone devoid of both Danian index
species and of those characteristic of the Upper Paleocene. This zone is
marked by the first appearance of the truncated Globorotalia species and
by a flood of the Globorotalia angulata group. It is here named the Globo-
votalia angulata Zone and is considered, on the basis of its stratigraphical
position, to be of Middle Paleocene age.

(e) The middle and upper members of the Owaina shale formation coincide with
the Globorotalia velascoensis Zone which is of Upper Paleocene age as
discussed above. However, it is worth noting that the first appearance of
Globorotalia velascoensis does not precisely coincide with the base of the
intercalated chalk bed (the Middle Owaina chalk member), but occurs
slightly below it in a band of calcareous shale with thin chalky bands
which is considered transitional to the Middle Owaina chalk member.

(f) The Owaina shale formation is overlain by the Globorotalia wilcoxensis
Zone of Lower Eocene age (see Text-figs. 5 and 6).

Thus it is evident that the Owaina shale formation is of Paleocene age, that its
basal part corresponds to the Upper Danian in its type section and elsewhere, and
that its upper part correlates with the known Upper Paleocene in various parts of
the world. However, in view of the confusion about the planktonic foraminiferal
content of the various stages of the Paleocene (see p. 25 et seq.), the author decided
not to use the known Paleocene stage names (e.g. Montian, Thanetian, Landenian,
Seelandian, [lerdian)*, but to divide the Paleocene into three major divisions, lower,
middle and upper, on the basis of its three planktonic foraminiferal zones, as discus-
sed above (see pp. 24-31) and summarized on Text-figs. 5 and 6.

The planktonic Foraminifera of the Owaina shale formation correlates it with
known Paleocene sections elsewhere in the world (Text-fig. 6), and its macrofossils
clearly relate it to similar successions in Egypt (Zittel 1883 ; Quaas 1902 ; Wanner
1902 ; Oppenheim 1902 ; Hume ro1I ; Cuvillier 1937a, b ; Youssef 1955, 1957 ;
Hassan 1956 ; Hermina ef al., 1961. However, the misunderstanding of the true
nature of the Cretaceous—Tertiary contact in Upper Egypt introduced by Zittel (1883)

4 See footnote 2

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 51

and repeated by Faris (1947) has completely confused the identity of the Paleocene
in Egypt. The fact that the stratigraphical break was overlooked, led authors to
assign the Owaina shale formation either partly or completely to the Danian. It
also led, as mentioned above, to the erroneous classification of the Esna shale into a
lower and upper member, separated by the middle chalk. As a result, the lower
Owaina shale member was lumped together with all or part of the underlying
Sharawna shale under the name “ Lower Esna shale’’. The latter, together with
the overlying chalk bed were assigned by most authors to the Danian, while others
also included the overlying shale succession in the “‘ Danian ”’

Analysis of the various Paleocene successions described by previous authors who
wrongly assigned them to the Cretaceous and/or the Tertiary, shows the widespread
nature of the Owaina shale formation, the persistence of its lithological units and the
great extent of the Paleocene transgression over the Egyptian territory, (which
possibly represents the greatest transgression in the geological history of Egypt).
It also shows clearly the applicability of the term ‘‘ Owaina shale’ over vast areas
in Egypt, although the formation becomes progressively more calcareous towards
the north.

(5) THE THEBES LIMESTONE AND CALCAREOUS SHALE FORMATION.

This formation is considered to be of Lower Eocene age for the following reasons:

(a) It conformably overlies the “Upper Owaina shale member” which is
proved to be of uppermost Paleocene age.

(b) Its lower member, the “ Thebes calcareous shale ’’, contains a rich planktonic
foraminiferal fauna which correlates it with the Lower Eocene in various
parts of the world (Text-fig. 6). Among these, Globorotalia wilcoxensis
Cushman & Ponton is worth mentioning as it is taken as a guide fossil for
the Lower Eocene, in spite of its occurrence in the uppermost part of the
underlying Paleocene (see discussion under this species). Also of import-
ance in this assemblage is Globorotalia bollii (=Globorotalia rex of Bolli
1957b) which is considered by various authors as the zone marker of the
Lower Eocene (see Text-fig. 6).

(c) The lithology and fauna of the “‘ Thebes limestone member ”’ of the Esna—
Idfu region correlate it with the “‘ Thebes limestone ”’ in its type section
(Delanoue 1868 ; Said 1960) and its equivalents elsewhere, which were
generally assigned to the Lower Libyan. Such characteristic lithology
and fossil content are almost uniform over a vast extent of the Egyptian
territory, constituting a particular rock unit which is generally assigned to
the Lower Eocene (Zittel 1883 ; Cuvillier 1930, etc.).

(d) Although washed samples from the “ Thebes limestone member”’ of the
Esna—Idfu region did not yield any identifiable planktonic Foraminifera
(possibly because of its silicification), samples from the type section at
Thebes were recorded by Said (1960) to contain a few planktonic forms.
These, although misidentified, support the Lower Eocene age of the type
Thebes limestone.

52 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

Thus, it is evident that the Thebes limestone and calcareous shale formation
is of Lower Eocene age. However, the controversy about the stratigraphical
relationship between the Ypresian and Cuisian stages, necessitates the avoidance of
the use of these terms in Lower Eocene stratigraphy, until their chronological
relationship is clarified.® For example, while some authors tended to use the Ypre-
sian followed by the Cuisian within the Lower Eocene, Hottinger & Schaub (1960)
used the Cuisian as the Lower Eocene, and Feugueur (1962) equated the Cuisian
with the Upper Ypresian.

ivy EPALAEONTOEOGY

A. THE MACROFAUNA

Systematic studies of the macrofossils of the Upper Cretaceous—Lower Tertiary
rocks of Egypt were carried out by Zittel (1883), Quass (1902), Wanner (1902),
Oppenheim (1902), Fourtau (1899-1921), Peron & Fourtau (1904), Stefano (19g12-
1919), Priem (1914) Greco (1915-1918), Stefanini (1918—1919)® and Abbass (1962).

In the present study, macrofossils are used for correlation with similar successions
previously zoned on the basis of macrofossils alone. However, most of these fossils
are unknown outside the Tethyan region and their ranges have been much disputed
in the past. Study of the associated planktonic Foraminifera in the Esna—Idfu
region has helped to define the ranges of the macrofossils in terms of the foraminiferal
zonation, and has thus cleared up some of the confusion.

One hundred and forty two macrofossil species are identified and their ranges
considered (Text-fig. 17). However, no attempt has been made to carry out a
systematic study of these macrofossil species which are only listed alphabetically
within their respective phyla (Text-fig. 17).

Consideration of the ranges of these macrofossils, has led to the recognition of five
major faunal zones and three subzones, in addition to a non-fossiliferous zone at the
base, and a zone devoid of macrofossils towards the top of the succession (Text-figs.
5, 8 and 17). These zones and subzones are correlated with the corresponding
planktonic foraminiferal zones and subzones in Text-fig. 5 ; they are arranged from
the base upwards as follows:

1. A non-fossiliferous zone.
2. The Lopha villet Zone.
3. The Pecten (Chlamys) mayereymari Zone.
(a) The Terebratulina gracilis Subzone.
(b) The Pecten (Chlamys) mayereymart Subzone.
(c) The Libycoceras berisensis Subzone.
Ann ~Disconformity wn

5 See footnote
® See Keldani 1941

a ,
Se

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 53

The Caryosmilia garnosa Zone.
The Ostrea hypoptera Zone.

A non-megafossiliferous zone.
7. The Lucina thebaica Zone.

In view of the restricted geographical distribution of most of these macrofossils,
the above-mentioned zones may be regarded as of local importance only. Neverthe-
less, analysis of previously described Upper Cretaceous—Lower Tertiary successions
in Egypt, North Africa and the Middle East points to the possible existence of these
zones at corresponding horizons all over this region. Some of the index fossils of
these zones, e.g., Lopha villei and Libycoceras spp. (L. ismaeli Zittel, L. chargense
Blanckenhorn and possibly L. phosphaticus Awad & Naiem and L. berisensis Awad &
Naiem) are known to flood corresponding horizons in North Africa, (Laffitte 1934,
1939), while the same species, in addition to Pecten (Chlamys) mayereymari Bullen-
Newton and Terebratulina gracilis Schlotheim, are recorded in abundance in similar
formations in Palestine (Parnes 1956). Thus, although it is understood that these
macrofossil zones are not of the world-wide importance of the corresponding plank-
tonic foraminiferal zones, they may be successfully applied in North Africa and the
Middle East. The value of these zones is now enhanced by the fact that they have
been defined in the light of the corresponding planktonic foraminiferal zonation,
and can thus be used in the absence of planktonic Foraminifera.

salle

B. THE PLANKTONIC FORAMINIFERA

The Foraminifera of the Upper Cretaceous and Lower Tertiary rocks of Egypt
have been dealt with by Nakkady (1949, 1950, 195Ia, 1952, 1955, 1957, 1959),
Nakkady & Osman (1954), Osman (1954, 19554, b, c), Le Roy (1949, 1953), Omara
(1954, 1955, 1956), Said & Kenawy (1956), Said (1960) and Said & Kerdany (1961).
However, very little has been published on the planktonic Foraminifera in spite of
their abundance, and reliance on the benthonic Foraminifera in stratigraphical
zonation has led to a great deal of discrepancy and confusion. In this connection
Bolli (19574 : 62) stated that ‘“‘ The complete change of the planktonic foraminiferal
fauna between the Upper Cretaceous Guayaguayare formation and the Paleocene—
Lower Eocene Lizard Springs formation, is not followed by the benthonic Foramin-
ifera ..., as many as about two-thirds of the benthonic species known in the Upper
Cretaceous continue into the Paleocene-Lower Eocene. In cases where only
benthonic Foraminifera are present, it may become difficult, therefore, to determine
whether a fauna is of Upper Cretaceous or Paleocene age’’. The same is true in
Egypt, where it has been found essential to establish the stratigraphy of the Upper
Cretaceous—Lower Tertiary period on the basis of planktonic Foraminifera which
were only briefly dealt with before, and were very much confused and misidentified.

Although Nakkady (1951a) was one of the earliest micropalaeontologists to
emphasize the value of planktonic Foraminifera in the zonation of the Cretaceous—
‘Tertiary transition period, he only discussed them very briefly in his study on the
Foraminifera of the Esna shale. Nakkady (1950, 1951a) recorded the occurrence of
the following planktonic Foraminifera from the Maestrichtian-Lower Eocene

54

UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

succession of six widely-separated sections in Egypt : Globotruncana aegyptiaca
Nakkady, G. aegyptiaca var. duwi Nakkady, G. aegyptiaca var. I. Nakkady, G. arca
(Cushman), G. arca (Cushman) var. esnehensis Nakkady, G. cretacea Cushman,
G. pseudocretacea Nakkady ; Globigerina bulloides d’Orbigny, G. cretacea d’Orbigny,
G. cretacea d’Orbigny var. esnehensis Nakkady, G. linaperta Finlay, G. quadrata White ;
Globorotalia colligera (Schwager), G. colligera (Schwager) var.crassaformis (Galloway
& Wissler), G. crassata (Cushman) var. aequa Cushman & Reuz, G. deceptoria
(Schwager), G. stmulatilis (Schwager), and G. velascoensis (Cushman).

However, examination of his specimens in the British Museum (Natural History),
London, showed clearly that:

1G

On

Io.

bE.

G. aegyptiaca var. I is an entirely single-keeled form which belongs to the
Globotruncana ganssert group.

Typical forms of Globotruncana stuarti stuarti (de Lapparent) were included
within his G. avca (Cushman), and thus the former species was not recorded
in spite of its abundance in his material and in the Egyptian Maestrichtain
rocks in general.

G. arca var. esnehensis is a distinct species from G. avca (Cushman) as realized
by Nakkady & Osman (1954), and is thus treated separately.

Specimens of G. cretacea Cushman actually belong to Globotruncana stuarti
stuartiformis Dalbiez, G. gagnebim Tilev, and G. aegyptiaca aegyptiaca
Nakkady.

G. pseudocretacea sp. nov. is probably Globotruncana gagnebimi Tilev.

G. bulloides d’Orbigny includes some forms related to Globigerina bacuana
Khalilov and others, which though indeterminable, are completely different
from the form of d’Orbigny.

Forms described as G. cretacea d’Orbigny are actually Globorotalia trimda-
densis Bolli G. compressa (Plummer) and G. cf. pseudobulloides (Plummer).
The form described by d’Orbigny is a true Globotruncana, not a Globigerina,
and does not cross the Campanian—Maestrichtian boundary.

The holotype of G. cretacea var. esnehensis is actually Globigerina mckannat
White, while the paratype is a transitional stage between Globorotalia
pseudobulloides (Plummer) and G. trinidadensis Bolli.

G. linaperta Finlay is Globigerina triloculinoides Plummer.

Globigerina quadrata White includes Globorotalia irrorata Loeblich & Tappan,
G. tribulosa Loeblich & Tappan, Globigerina triloculinoides Plummer,
besides Globorotalia quadrata (White).

Specimens of G. colligera (Schwager) belong to Globorotalia cf. subbotinae
Morozova, G. cf. aequa Cushman & Renz, and G. cf. wilcoxensis Cushman
& Ponton. The form described by Schwager was recorded from younger
strata and is not well known. Until the holotype is refigured and rede-
scribed in more detail, it is not really known what is meant by G. colligera
(Schwager).

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 55

12. G. colligera (Schwager) var. crassaformis (Galloway & Wissler) is G. wilcoxensis
Cushman & Ponton.

13. G. crassata var. aequa Cushman & Renz includes Globorotalia rex Martin,
G. aequa Cushman & Renz and other unknown forms.

14. G. deceptoria (Schwager) includes various forms of Globigerina and Globorotalia
e.g. Globorotalia aequa Cushman & Renz, G. wilcoxensis Cushman & Ponton,
and G. whitei Weiss ; Globigerina stone: Weiss, and G. valascoensis Cushman.

15. G. simulatilis (Schwager) includes Globorotalia rex Martin, G. occlusa Loeblich
& Tappan, G. velascoensis parva Rey, G. cf. pseudoscitula Glaessner, G.
emilei sp. nov., and G. cf. angulata abundocamerata Bolli. Again, G.
simulatilis was recorded from younger strata, and its holotype needs to be
redrawn and redescribed in more detail.

16. G. velascoensis (Cushman) includes G. velascoensis velascoensis (Cushman),
G. cf. angulata angulata (White), G. cf. angulata abundocamerata Boll,
G. cf. pseudoscitula Glaessner, and G. cf. occlusa Loeblich & Tappan.

Nevertheless, on the basis of these few planktonic forms, Nakkady established
three biozones in the Mesozoic—Cainozoic transition beds of Egypt : a Globotruncana
Zone of Maestrichtian age, a Globorotalia Zone of Paleocene age and an intervening
Buffer Zone of Danian age, distinguished by the complete absence or extreme
scarcity of both Globorotalia and Globotruncana.

Nakkady’s pioneering attempt was mainly based on genera, and as the planktonic
Foraminifera are known to exhibit an abrupt change in their generic composition at
the Cretaceous—Tertiary boundary all over the world, his Maestrichtian—Danian
boundary was correctly drawn. However, he neither recognized the Tertiary
character of the Danian fauna, nor the obvious stratigraphical break between the
Upper Cretaceous and the basal Tertiary, which can be easily seen on his chart
(19514), where his Buffer zone was shown to vary greatly in thickness. Moreover,
in his later studies, Nakkady confused the limits between the various stages of the
Paleocene and between the Paleocene and the overlying Eocene. Nevertheless, his
faunal sequence (a Globotruncana Zone, followed by a Buffer or Globigerina Zone and
a Globorotalia Zone, for the Maestrichtian, Danian and Paleocene respectively) has
since been observed in many parts of the world and has been used as a basis for the
precise zonation of the Cretaceous—Tertiary succession.

Nakkady (1959) recorded the following planktonic Foraminifera from what he
considered as Maestrichtian—Montian of the Um Elghanayem section, Kharga Oasis,
Egypt : Globotruncana aegyptiaca Nakkady, G. quadvata Nakkady & Osman ;
Globorotalia angulata (White), G. crassata var. aequa Cushman & Renz, G. deceptoria
(Schwager), G. pseudomenardu Bolli, G. quadrata Nakkady & Talaat, G. simulatilis
(Schwager), G. velascoensis (Cushman) ; Globigerina esnaensis Le Roy, G. mckannai
White, G. pseudobulloides Plummer, G. quadrata White, and G. triloculinoides

56 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

Plummer. Although he did not figure all his forms, analysis of his figures and
descriptions showed that:

1. G. angulata (White) probably belongs to Globorotalia occlusa Loeblich &
Tappan, while G. quadvata Nakkady & Talaat belongs to Globorotalia
angulata angulata (White).

2. G. simulatilis (Schwager) is probably Globorotalia acuta Toulmin.

G. velascoensis (Cushman) is probably G. angulata abundocamerata Bolli.

4. G. pseudobulloides Plummer is probably a transitional stage between Globoro-
talia trinidadensis Bolli and Globorotalia pseudobulloides (Plummet).

5. G. quadrata White is probably Globorotalia pseudobulloides (Plummer), and his
G. triloculinoides Plummer is Globigerina triloculinoides parva subsp. nov.

Moreover, his record of Globigerina quadrata White and G. triloculinoides

Plummer throughout the Upper Cretaceous—basal Tertiary succession
points to the possibility that he had lumped apparently similar Rugoglobi-
gerina and Hedbergella forms with these species and thus extended their
ranges.

hs

Nakkady & Osman (1954) briefly discussed the genus Globotruncana in Egypt and
its value in stratigraphical zonation, basing their discussion on the Maestrichtian
sections, previously studied by Nakkady (1949, 1950, I95Ia, 1952) and on the
Campanian—Maestrichtian of Qabeliat and Sudr sections, western Sinai. These
authors described seventeen species and four varieties of Globotruncana, most of
which were new, but, unfortunately, their descriptions are very short and their
figures very poor. These forms were cited as follows : Globotruncana aegyptiaca
Nakkady, G. aegyptiaca var. duwit Nakkady, G. aegyptiaca var. I. Nakkady, G.
ansarww Nakkady & Osman, G. caliciformis (de Lapparent), G. contusa (Cushman),
G. cretacea Cushman, G. esnehensis Nakkady & Osman, G. gansseri Bolli, G. globigen-
notdes Brotzen, G. lapparenti Brotzen, G. pooleyi Nakkady & Osman, G. pseudo-
fornicata Nakkady & Osman, G. qabeliatensis Nakkady & Osman, G. quadrata
Nakkady & Osman, G. quadrata var. plata Nakkady & Osman, G. rosetta (Carsey),
G. sudrensis Nakkady & Osman, G. sudrensis var. parallela Nakkady & Osman,
G. torensis Nakkady & Osman, and G. ventricosa White.

The holotypes of these forms need to be re-examined, refigured, and redescribed in
more detail so that their true identities can be established, and their relationships to
previously described species decided.

Le Roy (1953) recorded the following planktonic Foraminifera from the Maestrich-
tian—Lower Eocene succession of the Maqfi section, Farafra Oasis, Egypt : Globo-
truncna canaliculata (Reuss) ; Globigerina esnaensis Le Roy, G. pseudotriloba White,
G. subcretacea Lomnicki ; Globorotalia membranacea (Ehrenberg), G. simulatilis
(Schwager) and G. velascoensis (Cushman).

Analysis of his descriptions and figures showed that:
1. G. canaliculata (Reuss) is most probably Globotruncana arca (Cushman).
2. G. esnaensis Le Roy is a Globorotalia.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 57

3. G. pseudotriloba White is probably Globigerina linaperta Finlay.

4. Apparently he had included under G. subcretacea Lomnicki several Hedbergella,
Globigerinelloides, Rugoglobigerina, Globigerina and Globorotalia species, thus
extending its range from the Maestrichtian to the Lower Eocene. His
figured specimen is probably a species of Hedbergella or Globigerinelloides,
but the lack of a side view and the brief description make an accurate
determination impossible.

5. G. membranacea (Ehrenberg) probably belongs to Globorotalia emilei sp. nov.
while G. simulatilis (Schwager) should be assigned to Globorotalia vex Martin,
and G. velascoensis (Cushman) to G. velascoensis velascoensis (Cushman).

Said & Kenawy (1956) recorded the following planktonic Foraminifera from the
Maestrichtian—Lower Eocene succession of the Giddi and the Nekhl sections, north-
ern Sinai, Egypt : Globotruncana aegyptiaca Nakkady, G. caliciformis Vogler, G.
conica White, G. esnehensis Nakkady, G. ganssert Bolli, G. lapparenti lapparenti
Brotzen, G. lapparenti tricarinata (Quereau), G. mayaroensis Bolli, G. intermedia
Bolli, G. stuarti de Lapparent; Rugoglobigerina “ cretacea Cushman ”’ of Bermudez
1952, R. esnehensis (Nakkady) ; Globigerina bulloides d’Orbigny, G. linaperta Finlay,
G. pseudotriloba White, G. subcretacea Lomnicki ; Globorotalia membranacea (Ehren-
berg), Tvuncorotalia colligera (Schwager), T. crassata aequa (Cushman & Renz),
T. esnaensis (Le Roy), T. simulatilis (Schwager), T. sbinulosa (Cushman), T. velasco-
ensis (Cushman), and T. wilcoxensis (Cushman & Ponton).

ce

Examination of their figures and very brief descriptions showed that :

I. G. aegyptiaca Nakkady is an entirely single-keeled form which should be
assigned to Globotruncana stuarti parva Gaudolfi.

G. caliciformis (de Lapparent) (not Vogler), G. intermedia Bolli, G. stwarti (de
Lapparent) and G. esnehensis Nakkady are all the same species and should be
assigned to Globotruncana esnehensis Nakkady & Osman.

3. G. gansseri Bolli, G. lapparenti tricarinata (Quereau), R. esnehensis (Nakkady),
G. cretacea Lomnicki, G. membranacea (Ehrenberg), T. esnaensis (Le Roy)
and T. sbinulosa (Cushman) are doubtful forms.

4. G. lapparenti lapparenti Brotzen probably belongs to Abathomphalus mayar-
oensts (Bolli) as does G. mayaroensis Bolli.

5. Rugoglobigerina “ cretacea Cushman” of Bermudez, is possibly Globorotalia
quadrata (White).

6. Globigerina bulloides d’Orbigny is possibly Globorotalia pseudobulloides (Plum-
mer), and both their G. linaperta Finlay, and G. pseudotriloba White probab-
ly belong to G. tviloculinoides Plummer.

T. colligera (Schwager) probably belongs to Globorotalia angulata abundo-
camerata Bolli. Schwager’s form was recorded from younger strata, and
the holotype of this species needs to be redrawn and redescribed as mentioned
above.

8. T. crassata aequa (Cushman & Renz) and T. wilcoxensis (Cushman & Ponton)

probably belong to Globorotalia avagonensis Nuttall.

»

”

58 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

g. T. esnaensis (Le Roy) probably belongs to Globorotalia whitei Wiess.

10. Both their T. stmulatilis (Schwager) and T. spinulosa (Cushman) probably
belong to Globorotalia bollii sp. nov., and their T. velascoensis (Cushman) is
probably Globorotalia angulata angulata (White) or a transitional form
between it and G. angulata abundocamerata Bolli.

Said (1960) recorded the occurrence of three species of Globigerina, nine species of
Globorotalia, and two species of Hastigerina in the shale and limestone succession of
the Gebel Gurnah section, Luxor, which he regarded as Landenian—Ypresian in
age. Again, practically all the species were misidentified and thus the stratigraphy
was not correctly interpreted. Analysis of his description and figures showed that :

1. Globigerina eocaena Giimbel probably belongs to Globigerina turgida Finlay.

2. Globigerina inaequispira Subbotina probably belongs to Globigerina pseudo-
eocaena Subbotina.

3. Globigerina triloculinoides Plummer does not belong to this species, but may
be one of its descendants.

4. Globorotalia comcotruncata Subbotina is a doubtful form ; Subbotina’s
species is a junior synonym of Globorotalia angulata (White), while his
figures are different.

5. Globorotalia imitata Subbotina is a doubtful form ; it is different from
Subbotina’s original description and figures, and from hypotypes of G.
imutata recorded in the present work.

6. Globorotalia interposita Subbotina probably belongs to Globigerina soldadoensis
Bronnimann.

7. Globorotalia pentacamerata (Subbotina) is probably Globigerina mckannat
White.

8. Globorotalia planoconica Subbotina is not a Globorotalia but may be referable
to the genus Globanomalina [?Globanomalina eocenica (Berggren) ] as are his
Hastigerina aspera (Ehrenberg) and Hastigerina micra (Cole). Ehrenberg’s
original form most probably belongs to the genus Globigerinelloides, and is
not recorded from strata younger than Upper Campanian.

9. Globorotalia pseudotopilensis (Subbotina) is probably Globorotalia esnaensis
(Le Roy).

10. Globorotalia simulatilis (Schwager) is probably Globorotalia subbotinae Morozova.

11. Globorotalia thebaica Said is a junior synonym of Globorotalia prolata Bolli.

12. Globorotalia velascoensis (Cushman) is possibly Globorotalia formosa formosa
Bolli.

Said & Kerdany (1961) described the following planktonic Foraminifera from the
Maestrichtian—Lower Eocene succession of the Ain Maqfi section, Farafra Oasis,
Egypt : Globotruncana arca (Cushman), G. cretacea Cushman, G. esnehensis Nakkady,
G. gansseri Bolli, G. rosetta (Carsey) ; Rugoglobigerina sp. cf. R. jerseyensis Olsson,
R. veicheli pustulata Bronnimann ; Globigerina eocaena Giimbel, G. sp. cf. G. quadrata
White, G. triloculinoides Plummer ; Globorotalia angulata abundocamerata Bolli,
G. colligera (Schwager), G. convexa Subbotina, G. esnaensis (Le Roy), G. imitata

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 59

Subbotina, G. pentacamerata Subbotina, G. pseudomenardu Bolli, G. pseudoscitula
Glaessner, G. simulatilis (Schwager), G. triplex (Subbotina), G. varianta (Subbotina),
and G. velascoensis (Cushman).

Analysis of their descriptions and figures showed that:

I. G. arvca (Cushman) is probably Globotruncana gagnebini Tilev.

2. G. gansseri Bolli is possibly Globotruncana rosetta rosetta (Carsey).

3. G. rosetta (Carsey) is Globotrunacna stuarti stuarti (de Lapparent).

4. G. eocaena Giimbel is apparently Globigerina turgida Finlay.

5. G. convexa Subbotina is most probably Globorotalia angulata abundocamerata
Bolli, while the figure described by them under the latter name is a doubtful
form which is completely different from Bolli’s original description and
figures.

6. G. pentacamerata Subbotina is Globigerina mckannat White.

7. G. simulatilis (Schwager) probably belongs to Globorotalia occlusa Loeblich &

Tappan.

G. triplex (Subbotina) is probably Globorotalia loeblicht sp. nov.

g. G. varianta (Subbotina) is possibly Globorotalia pseudobulloides (Plummer)
while their G. valescoensis (Cushman) should be assigned to Globorotalia
velascoensis velascoensis (Cushman).

10. Rugoglobigerina reicheli pustulatais probably Rugoglobigerina rugosa (Plummer),
while their R. sp. cf. R. jerseyensis Olsson, their G. cretacea Cushman,
Globorotalia tmitata Subbotina, G. pseudoscitula Glaessner, G. colligera
Schwager, and Globigerina triloculinoides Plummer, are doubtful forms.

-

In the present study, the rich planktonic foraminiferal fauna of the Upper Creta-
ceous—Lower Tertiary sections provided the only means for precise zonation and
inter-regional correlation. The short ranges of most species and their wide geo-
graphical distribution points to their great stratigraphical value. However, as is
indicated above, previous misidentifications, misinterpretations of stratigraphical
ranges, over-brief specific descriptions, crude figures, the abundance of synonyms
and homonyms, and the divergent views held by authors on various important
taxonomic problems have all helped to mask the value of many species of planktonic
Foraminifera in stratigraphical zonation and world correlation, and have filled the
literature with an overwhelming amount of confused data.

Although studies aimed at clarifying the identity and establishing the true
stratigraphical ranges of various planktonic species have already been made by
Cita (1948), Tilev (1951, 1952), Bolli (1951, 1957a, 6), Bolli, Loeblich & Tappan
(1957), Subbotina (1953), Gandolfi (1955), Brénnimann & Brown (1956), Loeblich
& Tappan (19574), Bolli & Cita (1960b), Berggren (1960a, 1962), Pessagno (1960,
1962), and Barr (1962), many problems were left unsolved and a new critical study
was badly needed. Thus, this part of the work is mainly devoted to a study of the
most important members of the recorded planktonic Foraminifera. Each species is
treated in detail. Full synonymies with figures and descriptions, to the end of
August, 1963, have been compiled (El-Naggar 1963), but, with a few exceptions, only
the correct identifications are listed here. References without figures and descrip-

60 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

tions are also discussed whenever necessary and the confusion surrounding the species
is explained in detail wherever possible.

Species of Globotruncana, Globorotalia and Globigerina are described and figured in
detail except for a few that are very rare. Species of Abathomphalus, Rugoglobi-
gerina, Tvinitella and Hedbergella are only listed and will be dealt with in detail ina
future publication, together with other planktonic Foraminifera such as Globigerinel-
loides, Pseudotextularia, Pseudoguembelina, Guembelina, Planoglobulina, Racemig-
uembelina and Heterohelix. Consideration of the ranges of these planktonic Foramin-
ifera has led to the recognition of seven faunal zones and four subzones ; in addition,
three other zones, which are either devoid of planktonic Foraminifera, or contain rare
indeterminable forms, have also been recognised. (Text-figs 5 and 6). These zones
and subzones are correlated with the corresponding macrofossil zones and subzones
(Text-fig. 5), and with various planktonic foraminiferal zones in other parts of the
world (Text-fig. 6), they are briefly discussed below and are from the base upwards, as
follows:

1. A non-fossiliferous zone.

2. Azone with rare indeterminable planktonic Foraminifera.

3. The Globotruncana fornicata Zone.

4. The Globotruncana gansseri Zone.

5. The Globotruncana esnehensis Zone.

An “Disconformity wanww

6. The Globorotalia compressa/Globigerina daubjergensis Zone.

7. The Globorotalia angulata Zone.

a. The Globorotalia uncinata Subzone.
b. The Globorotalia pusilla Subzone.
8. The Globorotalia velascoensis Zone.
a. The Globorotalia pseudomenardu Subzone.
b. The Globorotalia aequa | Globorotalia esnaensis Subzone.
g. The Globorotalia wilcoxensis Zone.
to. A zone with indeterminable planktonic Foraminifera.

1. A NON-FOSSILIFEROUS ZONE.

This zone coincides with the Nubia sandstone and variegated shale formation
which is mostly devoid of fossils except for rare plant and vertebrate remains.
Several samples were washed for foraminiferal investigation, but no Foraminifera
were observed.

2. A ZONE WITH RARE INDETERMINABLE PLANKTONIC FORAMINIFERA.

This zone coincides with the Sibaiya phosphate formation which contains extreme-
ly minute forms of Foraminifera, that could only be seen in thin section and thus
could not be identified with certainty.

3. THE Globotruncana fornicata ZONE.
This represents the lowest recognized planktonic foraminiferal zone in the succes-

PLANKTON

C

FORAM 1

N |

PER A tL

ZO Nn AT I

ON

S)

i a Gil presenristuoy GUTOR aca BAWSER ina BoLlineaen LOEBLICH) & TAPPANIi+s7,4) OLSSON +50) HAY. veo) PESSAGNO eso, ivan) BOLL & CITA vse.) LEONOV & ALIMARINA (ssi)
A ~ Ss : Gulf ond Atlantic Coostal Plains) New Jersey Coastal Plain, Tampico Embayment, Poderno d Adda Section The Caucasus
oO 1S |e us PUERTO RIC!
ev |e jo 2 NILE VALLEY, EGYPT | THE CAUCASUS, USSR. TUNISIA TRINIDAD USA USA MEXICO’ 0 ITALY. USSR
s ‘i Globorofala
s Globorotalia Globorotalia
lu 2]
a eS G margino- G. proenartanensis
@ Icoxensis rex rex
© }ssu tin bac
30m) dentota
© | sae zone
ir = zone (Zone of subzone one zone
Globorctalia/ 5
we Globorotalia | ei noeoitegys, | compressed] b Globorofalia Globorotaia velascoensis Globorotata IG. subsphoenco|
> Ros ele velascoensis Sone velcascoensis 1G concotruncotay
a 2S veloscoensis |_Subzone globorotalids)| © crassato/ zone zone 6 IL Excel
ou Globoratabo, Globorotalia TeX zone = Gl OE fadjikistanensis[
Sag Amancio || . . || Ghee | SeS— 248 loborotaliaiveascoenss! Globorolalia pseudomenardi Globorotaba
<q x3 zone _|pseudomenardhi meine pseudomenardi velascoense/ecuia/ | & | Goberotala acula/ pseudomenardi [plows
Sy uy IL subzone subgone zone 2 spiralis subzone 3 Ae Re zone zone aero subzone
ce Globorotalia Globorotalia a Cras Glob
= us f oratalia.
z W wae Globorotala ate G a ae pusilla © | pseudobuloides 2 8| Globorotalia Globorotalia pusila pusilla, ecinerciae |e
aS subzone f zone 3s 5 subzone:
Ld) O ately ongulalas) i spcralal Zones eS S | pseudobulodes € uncinata ae
tu |=32 oDoretene | rotalid-like || subzone Globorotolia 5 B id Globorotalia A Crseel |
[= =) hes zone uncinata uncinata subzone oS subzone subzone uncinata i 1
= subzone globorofalads) zone zone zone subzone
S tnvighs i =
|) iy Goborotata compresso/ |g ft Sibzone | Globorotala trnidadensis | compressa/doubjergensis || Cl0borotalia compresso/ °
«as WSioiae mia CCUOESSiepe zone pone CREE EES Cadre NES 5 Giobigerinades Globorotaba trindadensis G. pseudobulloides /
wor Y YZ - aa) S| g 5 “ <
S05 Rrehakino , 3 Idoubjergensis /Globigerina daubjergensis| G. daubjergensis
sag epigona
<Q) subzone zone zone
Qa zonule
<=
< Rugogjobigerina
EZ Abathomphalus
«wl @ a ]LLLizzzd eee jemeyense/, Abathomptious Globotruncana | Abathomphats| Absthomphaus
@ EE Globotruncana mayoroensis Hedbergella mayoroenss mayoroensis mayoroensis
=)i\Ke) 2 esnehensis monmouthensis contusa/ x
zone zone subzone
(e) oy mz = zone zone zone
| a| x = cools” stuarti
Pes TE lh Gkedeincana Globotruncana Globotruncana|
rt | & ‘assemblage
q oO = 3 = gansseri ae gonsseri gansseri
| re || & ene zone zone subzone
oO =
WW tS ut = aus Globotruncana
< lobolruncana Rugo'
o\)a = & = Sloboteuncara Globotruncana fornicato/ fruncana
} oa $s lopporenti lopporerti/
| =) of foricata orca fuart file)
Oo 36 tricorinota stuarti
g A zone ca assemblage | subzone
Z jee
Correlation of the Planktonic Foraminiferal Zones in the Upper Cretaceous-Lower Tertiary succession of the Esna-Idfu Region, Nile Valley, with the corresponding zones in other parts of the World.

Verter): SYS0 7408

Slipped masses

Thebes limestone &

Thebes limestone and
calcareous shale
formation

| Sharawna

-— <
Sibatya phosphate formation.

Upper Owaino shale.

Owaina

shale
formation. Middle Owaina chalk
|

|
| Lower Owaina shale

— Disconformity

Upper Shorawna shale

shale Middle Sharawna marl
formation
|

Lower Shorawna shale

M

ry

Nubia sandstone and

variegated shale
formation.

Generalized Section for the Esna-Idfu Region

Vertical scale mm 1900 0 10 20 30 40 50 metres

S| ts

FIG. 7

ESNA-IDFU REGION

CORRELATION CHART
OF THE
SECTIONS STUDIED

Vertical scale
em400 0 4 8 12 15m
fee

E LOWER EOCENE
PALEOCENE

<~ Disconformity. ~~
( MAESTRICHTIAN

B UPPER CAMPANIAN
A

CAMPANIAN and ?
PRE- CAMPANIAN.

-; Location and number
of samples studied

Cj = =
C = :
a won EEB ee ee
SEDI EL-BAYOUMI GEBEL KOM-MIR GEBEL EL-SHARAWNA WADI EL-SHARAWNA GEBEL_OWAINA ABOU SABOUN GEBEL A
14
SECTION EL-BAHARY SECTION SECTION SECTION SECTION SECTION SECTION

+

LITHOLOGY AND FOSSIL CONTENT

Py
Uy hy

Ue

Mk,
Gly

CF
Me

Yi al

un =
Ne
mm

Limestone with Nummulites ond Operculina spp, Lucina
thebaica, Conoclypeaus delanoui, etc

i
EG
ser)
Ot

Colcareous shale passing upward into marly and
Nummulites and Operculina spp;
5s except rare dwarfed forms seen
only in woshed residues

DS —<———<—$< $$,

GLOBOROTALIA WILCOXENSIS ZONE

THEBES CALCAREOUS SHALE

K=THEBES formation] %,

LIBYA GROUP.

“<

LOWER EOCENE

EOCENE

Nummulites and Operculina spp. appear
first time, macrofossils very rare and limited to
limonitic, dwarfed for looded with planktonic
Foraminifera of the G. velascoensis zone

NON-MEGAFOSSILIFEROUS

UPPER OWAINA SHALE

1-270

a, Ostrea hypo-
h planktonic

nd
elascoensis zone

HYPOPTERA
ZONE

OSTREA

GLOBOROTALIA VELASCOENSIS ZONE

MIDDLE
INA

OWA
CHALK

OWAINA

ormation

f

Tron-stained, light grey shale flooded with limonitic
fossils of the C granosa zone, ond with planktonic
Foraminifera of the G. compressa -G. doubjergensis

zone, G angulata zone ond the basal part of the
G yelascoensis zone

215:
oes

Twjth Ki trichtion Danian
PeLIarate Aotondluneste at he ag aS Tone

Iron-stained, locally Ferruginous, dark grey to greyish
black shales, with rare Pecten mayer-eymari, Libyco-
Ceras sp, Boculites ex gr. anceps, abundant, dwarted
macrofouna, and planktonic Foraminifera of the G. gan-
sseri, G esnehensis zone

ZONE

Gesneh-¢ 0. compressa|S.angulato

ensis
Zone

UPPER SHARAWNA SHALE

CARYOSMILIA GRANOSA

ZONE

jergerss Zone
one |

G.daubj
Z

LOWER OWAINA SHALE

Marls and marly clay flooded with Pecten mayer -
=eymari, Pycnodonta yesicularis and planktonic

(SHARAWNA
MARL

Ry

formation

GROUP

ESNA

:

MIDDLE

UPPER PALEOCENE

PALEOCENE

UPPER

MAESTRICHTIAN AAR

MIDDLE

Foraminifera of the G.gansseri zone

Iron-stained, greenish grey, locally ferruginous shale,
intercalated with thin marly bonds, containing Pec-

fen mayer-eymori, Pycnodonta vesicularis, Terebratuli-
no gracilis, Baculites ex gr anceps, Libycoceras cf
ismaéli and planktonic Foraminifera of the G. forni-
cata zone

PECTEN (CHLAMYS) MAYER — EYMARI

GLOBOTRUNCANA GANSSERI ZONE

GLOBOTRUNCANA FORNICATA ZONE

LOWER SHARAWNA SHALE

SHARAWNA

LOWER MAESTRICHTIAN

UPPER
DANIAN
LOWER

PALEOCENE
ANIAN PALEOCEN

MAESTRICHTIAN

Phosphates, marls and limestones wit
rgemoli, A. multidentata, ond abundant

L fo -
brate remains

Topha
villel

Zone

ton

UPPER
CAMPANIAN

I | +80

Alternating shales, sandy shales, shaley sandstone ond
sandstone, variegated, iron-stained, mostly devoid of
fossils except for some plant ond vertebrate remains

Sibiya
> |format-

formation

NUBIA

CAMPANIAN ond ? PRE -CAMPANIAN

SENONIAN

UPPER CRETACEOUS

Fia,

8.

Vertical Scale
cms 509 0 § 10 15 20 25 meters

per Gretaccous=Lower T

Columnar section of t

Rocks of the Esna-ldfu Region

is

- , '

hots
only oF the: 2 gras tor oie

~ ee pom = oa
rae SiGe Ten con

ote cae \ Drape

wth i #3 (cn

; + : a
at Crem Mayra oF ye Uy Temoterse - oh Is Surg ey ¢ = ( x a : 4
J “7. es : ; ee vind fee .
rn ees” (Migutan me ond ihe binge ped ot tie i . aa —< => H < = |
5. arlovceere Dane ‘si : ir } 4 ' s S| : =e Ee “or I
7 ’ i - > —
. | = . =F | ae
| j oP Te) fol ee
eT CTY SPRY Oepee n> a ~etepee |
mT ag sui taew it (5a) Spb) eee
votes ve" Agtiedieq' Muy 1iG) nea’ od? ii -VK - - -4 — _ ; a 7 (2 ’ : ,
" ~ | —=— — +.
VP ns APO RE Vi PDUG AMA Pete ature ye oy . ; ) =!) oft Se) |
. ' i -*/ ¥ = 4 t : : } - } = %, ie
WT) ‘é > : 4 ' a i & ae = Fam -
; \ 5 ’ ye : a a { i
b, ‘ J a + » | i <= ' i
; ; : - al a 4
“j _ 4 : |
— F é - : i
j :
ON ae nail: ~ ; i” am ¢ va ar / 1° i ; | Sal
i we Ti % Ri i tS PAG dy i btiGo; pawmie | , ° + ~¢
: wvhe ben je? Was Gug ( illbaLs SOUS Aig Aaj 0) ji —
in + Fi —* d i &\e-~ > ¥¥ 7 al Seer ion . Pv ’ y
tro nN ¢ ; Q eos , . , F t
ter a a a P J ~
ae) oy’ -
‘23 tq dee reu! i ~~
% A at wes oi ©. , ‘ oY
evs ie

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 61

sion studied. It is characterized by the flood of the various subspecies of the
Globotruncana fornicata group which is taken as the index species for the zone.

The top part of the G. fornicata Zone is marked by the diappearance of G. fornicata
fornicata, G. fornicata manaurensis, G. fornicata globulocamerata, G. contusa scutilla,
G. contusa witwickae, G. maria and G. tricarinata tricarinata, as well as by the first
appearance of G. gansseri ganssert, G. ganserrit subganserri, G. ganserri dicarinata,
G. lugeoni, G. aegyptiaca duwi, G. conica, G. contusa contusa, G. contusa patelliformis,
G. esnehensis, G. rosetta petterst, G. sharawnaensis, G. stuarti parva, G. subcircumnodi-
fer, G. sp. Rugoglobigerina glaessnert, R. macrocephala, R. penny, R. pustulata, and
Trimitella scottr.

It is also characterized by the presence of G. adamsi, G. aegyptiaca aegyptiaca,
G. arca, G. cf. convexa, G. fareedi, G. fundiconulosa, G. gagnebim, G. cf gagnebint,
G. leupoldi, G. maniet, G. orientalis, G. rosetta rosetta, G. stuarti stuarti, G. stuart
stuartiformis, G. stuarti subspinosa, G. tricarinata columbiana, G. ventricosa, G.
havanensis, Rugoglobigerina loetterli, R. rugosa, Hedbergella hessi compressiformis,
H. hessi hesst, H. mattsoni, H. monmouthensis, and H. petaloidea.

The G. fornicata Zone characterizes the “lower Sharawna shale member ”’ and
coincides with the Terebratulina gracilis Subzone of the macrofossil classification.
Both its planktonic foraminiferal and macrofossil content as well as its stratigraphi-
cal position (conformably overlying the Upper Campanian Lopha ville: Zone) suggest
a Lower Maestrichtian age as summarized above (see pp. 46-49).

4. THE Globotruncana gansserit ZONE.

This represents the second planktonic foraminiferal zone from the base of the
succession upwards. It coincides with both the “‘ Middle Sharawna marl member ”’
and the lower part of the overlying ‘“ Upper Sharawna shale member ’’. It is charac-
terized by the first appearance and the flood of the various subspecies of the G. gans-
seri group, which is taken as the index species for the zone. Its base is marked by the
top of the underlying G. fornicata Zone, and its top by the diappearance of G. arca,
G. bahiyjae, G. conica and G. sp. as well as by the great reduction in the number of
individuals of the G. gansseri group and the flooding of G. esnehensis, and by the
first appearance of R. rotundata.

It is also characterized by the presence of Globotruncana aegyptiaca aegyptiaca,
G. arabica, G. arca, G. bahiyae, G. cf. convexa, G. fareedi, G. fundiconulosa, G. gagnebint,
G. ganssert gandolfii, G. leupoldi, G. mariei, G. orientalis, G. rosetta rosetta, G.
stuartt stuarti, G. stuarti stuartiformis, G. stuarti subspinosa, G. youssefi, G.
havanensis, Abathomphalus intermedia, Hedbergella hessi compressiformis, H. hessi
hesst, H. monmouthensis, H. petaloidea, Rugoglobigerina glaessneri, R. loetterli, R.
macrocephala, R. pennyt, R. pustulata, R. rugosa, and Trinitella scotti, as well as by the
rare occurrence of the following forms at its base : G. adamsi, G. fornicata ackermanni,
G. fornicata cesarensis, G. cf. gagnebini, G. tricarinata colombiana, G. ventricosa and
Hedbergella mattsont.

62 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

The G. gansserit Zone characterizes the Middle Sharawna marl member as well as
the lower part of the Upper Sharawna shale member, and coincides with the Pecten
(Chlamys) mayereymart Sub-zone of the macro-fossil classification. Both its
planktonic foraminiferal and macrofossil content suggest a Middle Maestrichtian age
as indicated above (see pp. 47—49).

5. THE Globotruncana esnehensis ZONE.

This represents the third planktonic foraminiferal zone from the base of the
succession upwards, and characterizes the topmost part of the Cretaceous rocks in the
Esna-Idfu region. It is distinguished by the flood of Globotruncana esnehensis
Nakkady & Osman which is taken as the index fossil of the zone. Its upper part is
marked by a distinct break and by a well developed conglomerate which separates
it from the overlying basal Tertiary. At this break the genera Globotruncana,
Rugoglobigerina, Abathomphalus, Trinitella, Hedbergella, Globigerinelloides, Heter-
helix and Pseudotextularia ; all ammonites and mosasaurs, as well as a great number of
characteristic Upper Cretaceous species belonging to other groups, disappear
completely and abruptly.

The lower limit of the G. esnehensis Zone is marked by the flood of Globotruncana
esnehensis and by a great reduction in the number of individuals of the G. gansseri
Zone which all die out completely in its lower part, except G. ganssert gandolfu
which continues to the disconformity. The lower limit of this zone is also marked
by the disappearance of G. arca, G. bahijae, G, conica, and G. sp. and by the first
appearance of R. votundata.

The G. esnehensis Zone is generally characterized by the presence of Globotruncana
aegyptiaca aegyptiaca, G. aegyptiaca duwt, G. arabica, G. contusa contusa, G. contusa
patelliformis, G. cf. convexa, G. gagnebim, G. mariet, G. stuarti parva, G. subcircumno-
difer, G. havanensis, Abathomphalus intermedia, A. mayaroensis, Hedbergella mon-
mouthensis, H. petaloidea, Rugoglobigerina glaessneri, R. loetterli, R. pustulata, R.
macrocephala, R. penny, R. rotundata and R. rugosa, as well as the rare occurrence
of G. fareedi, members of the G. gansseri group, G. lewpoldi, G. lugeoni, G. orientalis,
G. sharawnaensis, G. youssefi, and H. hessi hessi at its base.

The G. esnehensis Zone is equivalent in part to the Abathomphalus mayaroensis
Zone which is considered in various parts of the world to represent the uppermost
Cretaceous, and is equated with the established uppermost Maestrichtian Belemmni-
tella casimirovensis Zone. However, although Abathomphalus mayaroensis was
recorded in the G. esnehensis Zone, the latter zone could not be named after it, in
spite of the advantage of this name in inter-regional correlation, as A. mayaroensis
was only recorded as a rare form, while G. esnehensis was found to flood this part of
the succession, wherever examined.

6. THE Globorotalia compressa/Globigerina daubjergensis ZONE.
This represents the fourth planktonic foraminiferal zone from the base of the
succession upwards. It characterizes the lower part of the Lower Owaina shale mem-

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 63

ber, which represents the lowermost Tertiary outcrop in the Esna—Idfu region, and
the first known definite Danian strata in Egypt. The lower Owaina shale member is
separated from the underlying Maestrichtian strata by a marked disconformity and
a well developed conglomerate in which a mixture of reworked Maestrichtian
macrofossils and typical Danain planktonic Foraminifera are recorded.

The Globorotalia compressa/Globigerina daubjergensis Zone is characterized by the
complete absence of the typical Upper Cretaceous Globotruncana, Abathomphalus,
Rugoglobigerina, Trinitella, Hedbergella assemblage, and by the first appearance of the
typical Tertiary, Globigerina/non-keeled Globorotalia assemblage. It is flooded with
Globorotalia compressa (Plummer) and Globigerina daubjergensis Bronnimann which
are considered as the index species for the zone.

The base of this zone is marked by the disconformity and by the first appearance of
the Globigerina/non-keeled Globorotalia assemblage. Its top is marked by the
disappearance of Globorotalia compressa, Globorotalia kilabiyaensis, Globigerina
daubjergensis and Globigerina arabica, and by the first appearance of Globorotalia
angulata angulata, Globorotalia enuler and Globigerina inaequispira. Moreover, it
is characterized by the abundance of the following Globorotalia species: G. pseudo-
bulloides, G. trinidadensis, G. quadrata, G. perclara, G. kilabiyaensis, G. imitata, and
the rare occurrence of G. ehrenbergi, G. faragi, G. tribulosa and G. uncinata uncinata
in its upper part. It is also characterized by the abundance of the following Globi-
gerina species: G. triloculinoides, G. triloculinoides parva, G. belli and by the rare
occurrence of G. haynesi, G. kozlowsku and G. spiralis, at its top.

The Globorotalia compressa/Globigerina daubjergensis Zone corresponds to the
lower part of the macrofossil Caryosmilia granosa Zone. The planktonic Foramini-
fera of this zone correlate it with the type Danian and thus prove a Danian age for its
rich macrofossil content. However, the reduced thickness of this zone and the flood
of Globorotalia compressa throughout it, show clearly that the strata it characterizes
in the Esna—Idfu region, represent the Upper Danian only, the Lower and Middle
Danian being missing (see Troelsen 1957 and Berggren 19600, 1962).

7. THE Globorotalia angulata ZONE.

This is the fifth planktonic foraminiferal zone from the base upwards, in the succes-
sion studied. It coincides with the upper part of the lower Owaina shale member,
and is characterized by the flood of Globorotalia angulata angulata (White) and its
suspecies abundocamerata. Its base is marked by the first appearance of G. angulata
angulata, G. emiler and by the disappearance of the typical Danian Globorotalia com-
pressa, G. kilabiyaensis, Globigerina daubjergensis and G. arabica.

The upper limit of this zone is drawn at the first appearance of Globorotalia
velascoensis velascoensis which characterizes and distinguishes the overlying zone.
This limit is also marked by the disappearance of Globorotalia ehrenbergi and G.
uncinata carinata, and by the first appearance of Globorotalia acuta, G. apanthesma,
G. cf. convexa, G. occlusa G. pseudomenardii, Globigerina alanwoodi and G. velasco-
nesis.

64 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

The zone is characterized by the abundance of the following Globorotalia species:
G. angulata angulata, G. angulata abundocamerata, G. ehrenbergi, G. emilei, G. faragi,
G. imitata, G. perclara, G. pseudobulloides, G. pusilla pusilla, G. pusilla laevigata, G.
pusilla mediterramica, G. quadrata, G. tribulosa, G. uncinata uncinata, G. uncinata
carinata and G. sp. It is also distinguished by the abundance of the following
Globigerina species : G. haynesi, G. inaequispira, G. kozlowskit, G. spiralis, G. trilo-
culinoides and G. triloculinoides parva.

It is divided into two distinct subzones : a lower, Globorotalia uncinata Subzone
and an upper, Globorotalia pusilla Subzone. The ranges of the various species
characteristic of each subzone are shown on Text-figs. 12-16.

The G. angulata Zone coincides with the upper part of the Carysomilia granosa
Zone of the macrofossil classification. Its planktonic Foraminifera as well as its
stratigraphical position (conformably overlying typical Upper Danian strata and
underlying the G. velascoensis Zone of Upper Paleocene age) proves its Middle
Paleocene age. However, as discussed earlier, the controversy over the chrono-
logical and stratigraphical relationships of the various Paleocene stages and sub-
stages, and the disagreement regarding their planktonic foraminiferal content, does
not allow one to refer the G. angulata Zone to any known Paleocene stage or substage

(see pp. 22-29, 59-61).

8. THE Globorotalia velascoensis ZONE.

This is the sixth planktonic foraminiferal zone from the base of the succession
upwards. It coincides with the upper two members of the Owaina formation, the
Middle Owaina chalk and the Upper Owaina shale members, and represents the Upper
Paleocene of the sections studied. It is characterized by the flood of Globorotalia
velascoensis velascoensis (Cushman) and its two subspecies payva and caucasica,
which are here considered as the index species for the zone.

The lower limit of the zone is marked by the first appearance of G. velascoensis
velascoensis, and its upper limit by the complete disappearance of the last survivors
of this species. The lower limit is also defined by the first appearance of the following
Globorotalia species : G. acuta, G. apanthesma, G. cf. convexa, G. occlusa, G. pseudo-
menardiu, and the first appearance of both Globigerina velascoensis and alanwoodt.

Its upper limit, besides being defined by the disappearance of G. velascoensis
velascoensis, is also marked by the disappearance of the following Globorotalia
species: G. acuta, G. angulata angulata, G. apanthesma, G. cf. convexa, G. nicoli, and
by the disappearance of the following Globigerina species : G. velascoensis, G. tri-
loculinoides, G. triloculinoides parva, G. inaequispiva, G. haynest, G. chascanona,
G. bacuana, and by the first appearance of Globorotalia bollit.

The G. velascoensis Zone is generally characterized by the abundance of the
following Globorotalia species : G. velascoensis velascoensis, G. velascoensis parva,
G. velascoensis caucasica, G. acuta, G. aequa, G. africana, G. angulata angulata,

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 65

G. angulata abundocamerata, G. apanthesma, G. berggrent, G. cf. convexa, G. emilet,
G. esnaensis, G. faragi, G. hispidicidaris, G. irrorata, G. woodi, G. nicolt, G. occlusa,
G. perclara, G. pseudomenardu, G. pusilla mediterranica, G. sibaiyaensis, G. tribulosa,
G. whitet, as well as the rare occurrence of G. imitata, G. pusilla pusilla, G. pusilla
laevigata, G. quadrata, G. pseudobulloides and G. sp. at its base, and G. wilcoxensis,
G. loeblichi, G. troelseni at its top.

It is also characterized by the abundance of the following Globigerina species :
G. aquiensis, G. bacuana, G. chascanona, G. haynesi, G. inaequispira, G. mckannat,
G. nodosa, G. soldadoensis, G. spiralis, G. stoner, G. triloculinoides, G. triloculinoides
parva, G. velascoensis and G. alanwoodt.

The G. velascoensis Zone is clearly divisible, on the basis of its planktonic Fora-
minifera, into two distinct subzones : a lower G. pseudomenardi Subzone and an
upper G. aequa/G. esnaensis Subzone. The lower subzone is distinguished by its
index species, G. pseudomenardi Bolli, which does not range into the overlying
subzone. The G. aequa/G. esnaensis Subzone is also characterized by its index
species which do not range into the underlying subzone, although rare forms of
G. aequa may be recorded in the uppermost part of the underlying subzone. The
distribution of the various planktonic foraminiferal species in each of these subzones
is clearly shown on Text-figs. 12-16.

The G. velascoensis Zone corresponds to the Ostrea hypoptera Zone and the lower
part of the non-megafossiliferous zone in the macrofossil zonal scheme. On the
basis of its planktonic foraminiferal content, and stratigraphical position, it is
considered to represent the Upper Paleocene as stated above (see pp. 29-31, 49-51).

9g. THE Globorotalia wilcoxensis ZONE.

This represents the last planktonic foraminiferal zone in the succession studied.
It coincides with the Thebes calcareous shale member and probably includes at
least part of the overlying Thebes limestone member, although the latter did not
yield any identifiable planktonic Foraminifera. It is characterized by the abun-
dance of Globorotalia wilcoxensis Cushman & Ponton, which is considered as the
index species of this zone.

The lower limit is marked by the disappearance of the following Globorotalia
species : G. velascoensis velascoensis, G. acuta, G. angulata angulata, G. apanthesma,
G. cf. convexa and G. nicoli as well as by the disappearance of the following Globi-
gerina species : G. bacuana, G. chascanona, G. haynesi, G. inaequispira, G. triloculi-
notdes, G. triloculinoides parva, and G. velascoensis. It is also marked by the first
appearance of G. bollit and the flood of G. wilcoxensis. The upper limit of the zone
is not really known in the succession studied, as no younger zones have yet been
recorded.

The G. wilcoxensis Zone is characterized by a flood of G. wilcoxensis, which species,
though appearing first as rare, scattered individuals in the uppermost part of the
underlying zone, is nevertheless considered to be a good index fossil. The zone is also

66 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

characterized by the abundance of the following Globorotalia species : G. troelsent,
G. whitet, G. bollii, G. aequa, G. esnaensis and G. loeblicht, as well as by the abundance
of both Globigerina stonei and Globigerina soldadoensis, and by the rare occurrence at
its base of both Globigerina mckannai and Globigerina aquiensis.

The G. wilcoxensis Zone corresponds to the upper part of the non-megafossiliferous
zone and possibly the lower part of the overlying Lucina thebaica Zone, in the macro-
fossil classification. On the basis of its planktonic Foraminifera, and stratigraphical
position, it is considered to mark the dawn of the Eocene as discussed above (see

Pp. 31,°32, 51, 52).

to. A ZONE WITH INDETERMINABLE PLANKTONIC FORAMINIFERA :

This zone coincides with the Thebes limestone member, of which only the lowest
ten metres crop out in the area studied. This hard, siliceous limestone bed which
caps the succession is flooded with Nummulites, Operculina, Assilina, Discocyclina,
etc., but has not yet yielded any identifiable planktonic Foraminifera, possibly
because of its silicification. Several samples of this bed are now being processed for
planktonic foraminiferal analysis using different techniques with the hope of recover-
ing some identifiable forms.

These planktonic foraminiferal zones clarify the stratigraphy of the Upper Creta-
ceous—Lower Tertiary in Egypt, and their recognition in other parts of the world
indicates that they can be successfully used for the zonation and world-wide correl-
ation of strata of this age.

V. SYSTEMATIC DESCRIPTIONS
Order FORAMINIFERIDA
Superfamily GLOBIGERINACEAE Carpenter, Parker & Jones 1862
Family GLOBOTRUNCANIDAE Brotzen 1942

This family is represented in the present study by the four genera, Globotruncana
Cushman 1927, Rugoglobigerina Bronnimann 1952, Tvimitella Bronnimann 1952, and
Abathomphalus Bolli, Loeblich & Tappan 1957. Forty-five species and subspecies of
Globotruncana, seven species of Rugoglobigerina, one species of Trinitella, and two
species of Abathomphalus are recorded. Members of the genus Globotruncana are
discussed in detail, while those of Rugoglobigerina, Trinitella and Abathomphalus are
only listed and will be figured and described in a later publication.

Genus ABATHOMPHALUS Bolli, Loeblich & Tappan 1957
Type species : Globotruncana mayaroensis Bolli 1951

Abathomphalus intermedia (Bolli)

1951 Globotruncana intermedia Bolli: 197, pl. 35, figs. 7-9.
1954 Globotrvuncana intermedia Bolli; Ayala: 399, pl. 7, figs. 2a—c.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 67

1955 Globotvuncana intermedia intermedia (Bolli) Gandolfi : 48, pl. 3, figs. 8a—c.

1956 Rugotruncana intermedia (Bolli) ; Bronnimann & Brown : 553, pl. 22, figs. 13-15.
1956b Marginotrucana intermedia (Bolli) Hofker : 333, text-fig. 24.

1956c Marginotruncana intermedia (Bolli) Hofker : 75, pl. 10, figs. 74a~c.

1960a Globotruncana (Marginotruncana) intermedia Bolli ; Hofker : 225, text-fig. 21a—c.
1962 Pyraeglobotruncana (Praeglobotruncana) intermedia (Bolli) Berggren : 31, pl. 7, figs 2a—c.

mwoeyou Uy

Remarks. A few specimens of A. intermedia (Bolli) were recorded from both the
Middle Maestrichtian G. ganssert Zone and the overlying Upper Maestrichtian
G. esnehensis Zone. The species was recorded from the Maestrichtian of Trinidad
(Bolli 1951, 19574), of northeastern Colombia (Gandolfi 1955), of Cuba (Brénnimann
& Brown 1956), of northwestern Germany and of Holland (Hofker 19560, c) and of
southern Scandinavia (Hofker 1960a ; Berggren 1962).

Hypotype. P.45659.

HoRIzON AND LocALITy. Hypotype from sample No. 16, Wadi EI-Sharawna
section.

Abathomphalus mayaroensis (Bolli)

1951 Globotvuncana mayaroensis Bolli: 198, pl. 35, figs. 1o—-12.

1953 Globotruncana mayaroensis Bolli: Subbotina ; 181, pl. 8, figs. 2a-c.

1954 Globotruncana mayaroensis Bolli; Ayala: 407, pl. to, figs. 1a—c.

1955 Globotruncana mayaroensis Bolli ; Gandolfi: 18, pl. 1, figs. 2a—c, text-fig. 4 (10a—b).

1956 Globotruncana mayaroensis Bolli ; Knipscheer (in Ganss & Knipscheer) : 624, pl. 2,
figs. 2a—c.

1956 Rugotyuncana mayaryoensis (Bolli) Bronnimann & Brown ; 553-554, pl. 22, figs. 10-12.

1956 Globotruncana mayaroensis Bolli ; Wicher : 136, pl. 13, figs. 7, 8.

1956 Globotruncana mayaroensis Bolli: Said & Kenawy : 151, pl. 5, figs. 23a-c.

1956 Globotruncana lapparenti lapparenti Brotzen ; Said & Kenawy : 150, pl. 5, figs. 14a—c.

1957 Globotyvuncana (Globotrvuncana) planata Edgell: 115, pl. 4, figs. 7-9.

1957 <Abathomphalus mayaroensis (Bolli) Bolli, Loeblich & Tappan : 43, pl. 11, figs. 1a—c.

1960 Globotruncana mayaroensis Bolli ; Vinogradov : 313, pl. 5, figs. 26a—c.

1962 Praeglobotyuncana (Praeglobotruncana) mayaroensis (Bolli) Berggren: 32-36, pl. 7,
figs. 3a-c.

wu

ww

REMARKS. Rare specimens of A. mayaroensis were recorded from the Upper
Maestrichtian (G. esnehensis Zone). The species was also recorded from the Upper
Maestrichtian of Trinidad (Bolli 1951, 1957a), of the Caucasus (Subbotina 1953), of
northeastern Colombia (Gandolfi 1955), of Bavaria (Knipscheer 1956), of Cuba
(Bronnimann & Brown 1956), of Austria (Wicher 1956), of northern Sinai, Egypt
(Said & Kenawy 1956), of Australia (Edgell 1957), of Rumania (Vinogradov 1960)
and of southern Scandinavia (Berggren 1962).

HypotyPe. P.45660.

HORIZON AND LOCALITY. Hypotype from sample No. 27, Wadi El-Sharawna
section.

68 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

Genus GLOBOTRUNCANA Cushman 1927
Type species: Pulvinulina area Cushman 1926

1927b Globotvuncana Cushman : 91 (Type species : Pulvinulina avca Cushman 1926).

1941 Josalinella Marie : 237 (Type species : Rosalina linneiana d’Orbigny 18309).

1956 Rugotyuncana Bronnimann & Brosn : 546 (Type species Rugotruncana tilevi Bré6nnimann
& Brown 1956).

1956 Bucherina Bronnimann & Brown : 557 (Type species : Bucherina sandidgei Brénnimann
& Brown, 1956).

1956b Marginotruncana Hofker : 319 (Type species : Rosalina marginata Reuss 1845).

1957a Globotvuncanella Reiss : 135 (Type species: Globotruncana citae Bolli 1951=Globo-

tyvuncana havanensis Voorwijk 1937).
1957a Globotvuncanita Reiss : 136 (Type species : Rosalina stuarti de Lapparent 1918).
1957a Helvetoglobotvuncana Reiss : 137 (Type species Globotruncana helvetica Bolli 1943).

EMENDED DiaGnosis: Test free, trochospirally coiled, with wide range of
variation in size and shape, highly or moderately spiro-convex, biconvex plano-
convex (umbilico-convex), concavo-convex, or even parallel-sided ; dorsal side
evolute, highly domed, convex, flat or even concave ; ventral side strongly umbilicate,
moderately or strongly protruding, convex, flat or even concave ; equatorial periph-
ery generally rounded or ovoid, sometimes polygonal, either entire or lobate, with
single or double keel ; in double keeled forms, the two keels may be parallel or diver-
gent, enclosing a narrow or wide peripheral band either at right angles or inclined to
plane or coiling ; axial periphery subrounded, subacute, acute, subtruncate or
truncate ; chambers generally arranged in 2-4 whorls, dextrally or sinistrally
coiled ; all chambers seen on dorsal side, only those of last whorl seen on ventral side ;
initial chambers generally globular, moderately or strongly inflated, later ones
variable in shape, being ovoid truncate, lenticular acute, hemispherical, angular
conical, angular truncate, angular rhomboid, etc. ; sutures on both sides curved or
radial, raised or depressed, sometimes thickened, limbate and beaded ; umbilicus
varies in shape and size, rounded, ovoid, stellate or polygonal, moderate or large, with
or without an umbilical flange ; primary apertures interiomarginal, umbilical, but
umbilicus covered by complex, imperforate cover-plate (tegilla) formed by fusion of
apertural flaps extending from each chamber ; these tegilla pierced centrally and at
their contacts with umbilical rim by a number of small accessory apertures along
which primary apertures and umbilical region in general communicate with outside of
test ; tegilla delicate with much thinner wall than rest of test and thus are rarely
preserved ; but even when broken they leave remnants along umbilical margin ;
wall calcareous perforate, except for imperforate keel or keels, peripheral band and
tegilla ; surface smooth or roughened, papillose, nodose, or even spinose ; keel or
keels, sutures and umbilical flange either thickened and limbate or strongly beaded ;
dorsal keel of each chamber reflected on dorsal side of test as inter-cameral dorsal
suture, dorsal keels of successive whorls constituting spiral suture ; ventral keel
(when present) reflected on ventral side of test as inter-cameral ventral suture (either
raised or depressed) ; it may continue along umbilical rim as raised, beaded, umbilical
flange ; i.e. dorsal keel of nepionic stage continuing on following chambers as dorsal
inter-cameral sutures, spiral suture and dorsal, marginal keel of last whorl, while

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 69

ventral keel of nepionic stage (when present) continues as ventral inter-cameral
suture, ventral marginal keel of last whorl and sometimes as umbilical flange. In
single-keeled forms keel occasionally bifurcating on periphery to form dorsal as well
as ventral inter-cameral suture, as in members of Globotruncana stuarti group.

Discussion. Cushman (1927)) described Globotruncana as a new genus, with
Pulvinulina arca Cushman 1926 as the type species. However, several species of
this genus had been previously assigned to the genus Rosalina d’Orbigny 1826
(e.g. R. marginata Reuss 1845, R. canaliculata Reuss 1854 and R. stuartt de Lapparent
1918). Thalmann (1933) considered Rosalina d’Orbigny to be a junior synonym of
Discorbis Lamarck 1804, and thus substantiated the validity of the genus Globo-
truncana. However, Brotzen (1948) stated that the type species of Dzscorbis
Lamarck has not been determined for certain, and thus retained Rosalina d’Orbigny
1826, and included in its synonymy : Discorbina Parker & Jones 1862, and Discorbts
Lamarck of authors (part). Nevertheless, the apertural characters, the large
umbilicus, the umbilical cover-plate, the keels and peripheral band, the shape of the
chambers, etc., clearly distinguish Globotruncana from the above genera.

The brief description of the apertural characters of the genus given by Cushman
(19276) led to further complication. He merely stated that the aperture is on the

ventral side, and later (1928) added ‘‘...aperture on the ventral side, often in
| well-preserved specimens with a thin plate-like structure over the umbilical area... ”’
However, Marie (1941) noticed that in morphologically similar forms, the apertures
of the previous chambers remain open into the umbilicus. Thus he suggested
including these forms in a separate genus which he named Rosalinella, with R. linnet
(d’Orbigny) as type species. He included within his new genus : Rosalina d’Orbigny
sensu de Lapparent 1918, Globotruncana Cushman 1927, Globorotalia Cushman 1927
(part), as well as Rosalna d’Orbigny (part), Discorbina Parker & Jones (part),
Globigerina d’Orbigny (part), Rotalia Lamarck (part) and Truncatulina d’Orbigny
(part) of authors. Marie divided his genus Rosalinella on the basis of the peripheral
character and general form of test into four subgenera which he did not name, but
listed with examples as follows :
I. Test with truncated periphery, bordered by two marginal keels.

I. Subgenus typified by Rosalinella inne: (d’Orbigny).

II. Test with acute periphery (single keeled) :

(A) Contour regular
[a] with large umbilicus.

2. Subgenus typified by Rosalinella stuarti (de Lapparent).
[b] with narrow umbilicus.

3. Subgenus typified by Rosalinella velascoensis (Cushman).

(B) Contour lobate
4. Subgenus typified by Rosalinella appenninica (Renz).

Thus, he included within his new genus, species typical of Globotruncana Cushman
1927, of Globorotalia Cushman 1927, and of Rotalipora Brotzen 1942. Nevertheless,
his description conforms well with that of Globotruncana as given by Cushman

70 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

(1927, 1928) and emended by later authors. Thus Rosalinella Marie 1941 is consid-
ered a junior synonym of Globotruncana Cushman 1927.

Reichel (1950) divided the genus Globotruncana into four subgenera : Globotruncana
s.s., Rotalipora Brotzen, Thalmanninella Sigal and Ticinella Reichel. However, the
apertural characters of the last three genera are different from those of Globotruncana
Cushman and they were therefore considered separately by Sigal (1952), Bolli,
Loeblich & Tappan (1957) and Banner & Blow (1959).

Gandolfi (1955) added a fifth subgenus to Reichel’s classification, considering
Rugoglobigerina Bronnimann as a subgenus of Globotruncana Cushman. However,
the absence of true keels and a peripheral band, the constant presence of well-develop-
ed surface rugosity, and the fact that the two forms have not yet been proved to
grade into one another, favour the consideration of Rugoglobigerina as a separate
genus.

Broénnimann & Brown (1956) described Rugotruncana as a new genus. They
distinguished it from Globotruncana by the fact that “ .. . some or all later chambers
exhibit fine discontinuous costellae or traces of costellae.”’, otherwise their descrip-
tions of the two genera are identical. However, as previously mentioned by Bolli,
Loeblich & Tappan (1957), surface ornamentation alone cannot be used as a generic
character, and thus Rogotruncana should be considered a junior synonym of Globo-
truncana, although Banner & Blow (1959) considered it as a subgenus of the latter.
Forms of Globotruncana with a highly roughened surface are recorded, and variation
of the surface rugosity within the same species population renders generic or sub-
generic distinction impossible on this basis alone. Moreover, Bronnimann & Brown
(1956) included Abathomphalus intermedia (Bolli) and A. mayaroensis (Bolli) within
Rugotruncana, in spite of the difference in the apertural characters of the two genera.
They also described Bucherina as a monotypic genus. They stated that it resembles
Globotruncana and Rugotruncana, but differs from both “in lacking an umbilical
cover-plate and in exhibiting a shift in the axis of coiling’’. They further stated
that “ short apertural flaps extend into the umbilicus but do not form a cover-plate’’.
However, as mentioned above, the cover-plate is a very delicate structure which is
rarely well-preserved, and the shift in the axis of coiling is not a generic character.
The establishment of a new genus on such a weak basis cannot be accepted, and
Bucherina Bronnimann & Brown is therefore considered a junior synonym of
Globotruncana Cushman. Again, these authors stated that Globigerina mckannat
White may possibly belong to their new genus Bucherina. However, no apertural
flaps were ever observed in G. mckannat, which is a true Globigerina, recorded only ~
from the Upper Paleocene and Lower Eocene, where no globotruncanid-like forms
are known.

Hofker (1956) proposed Marginotruncana as a new genus. He distinguished it
from Globotruncana Cushman on the basis of a so-called strongly reduced primary
aperture (protoforamen) in the latter, which is either completely lost or fused with
a secondary aperture (deuteroforamen) in the former. He included within Margino-
truncana, forms which actually belong to Globotruncana Cushman, Abathomphalus

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 71

Bolli, Loeblich & Tappan, Praeglobotruncana Bermudez and Rotalipora Brotzen, all
of which differ markedly in their apertural characters. Moreover, a deuteroforamen,
such as described by Hofker, had not been recorded in any of the forms he included
in his Marginotruncana [e.g. G. marginata Reuss, G. stuarti (de Lapparent), G. contusa,
(Cushman), etc.] which conform precisely with the description of the genus
Globotruncana as given by Cushman (1927) and emended by later authors. Thus
Marginotruncana Hofker is considered a junior synonym of Globotruncana Cushman.

Reiss (1957) described Globotruncanita as a new genus and distinguished it from
Globotruncana Cushman by its chamber form which is mostly polygonal in outline,
its entirely single keel, and by its “‘ distinctive apertural characters’’. However, as
admitted by Reiss, polygonal chambers are also recorded in Globotruncana Cushman.
Again, the character of the keel, whether single or double, is of specific importance
only within the genus Globotruncana, and cannot be used as a basis for splitting it into
two distinct genera. Forms with a double keel are clearly shown in the present
study to evolve into single-keeled forms (e.g. G. arca > G. leupoldt), all transitional
stages being present. Finally, there is no fundamental difference in the apertural
characters of the two genera as described by Reiss (1957) ; both have interiomarginal,
umbilical primary apertures, and a cover-plate with accessory apertures. Thus
Globotruncamita Reiss is considered a junior synonym of Globotruncana Cushman.

Reiss also described Globotruncanella and Helvetoglobotruncana as two new genera
and stated that Globotruncanella is closely related to Praeglobotruncana, although from
his description, it is clearly seen that its apertural characters relate it to Globotruncana
not to Praeglobotruncana. However, he distinguished Globotruncanella by its
flatly trochospiral test and its undifferentiated keel which never shows any tendency
to split into two keels (although his type species was observed in the present study
and by Broénnimann & Brown (1956) to have an occasional ventral keel in the last
chamber or two). Otherwise, his description conforms well with that of Globotruncana
Cushman. As the degree of flattening of the test and the double- or single-keeled
nature of the peripheral band are characters of specific, rather than generic, import-
ance, Globotruncanella Reiss is considered a junior synonym of Globotruncana
Cushman.

Similarly Helvetoglobotruncana was only distinguished by its rounded chambers
and its subperipheral, monochotamic keel. Again, chamber shape and position of
the keel cannot be accepted as generic characters. Forms of Globotruncana with
globular chambers and a dorsally-shifted keel (e.g. Globotruncana arabica sp. nov.)
are recorded in the present paper, and make the establishment of a new genus impos-
sible on the basis of such minor morphological characters. Thus Helvetoglobotruncana
Reiss is also considered a junior synonym of Globotruncana Cushman.

Globotruncana Cushman 1927 is distinguished from Rugoglobigerina Bronnimann
1952 by its keel or keels, imperforate peripheral band, less globular chambers and less
rugose surface. Tvinitella Bronnimann 1952 is transitional in character between
Globotruncana and Rugoglobigerina. It can neither be included in the former
because it lacks an entire keel and an imperforate peripheral band, nor in the latter

72 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

because of its compressed last chambers and partially developed keel. Thus it is
considered here separately, in spite of the fact that it is represented by only one
species, until further study can reveal its true position.

Globotruncana is distinguished from A bathomphalus Bolli, Loeblich & Tappan 1957
by its interiomarginal, umbilical aperture, which is extraumbilical in Abathomphalus ;
by its generally large umbilicus, which is very much reduced in the latter genus ;
by its complex tegilla which is single in Abathomphalus and by the fact that its
accessory apertures are both infra- and intralaminal, not only infralaminal as in
Abathomphalus.

Globotruncana differs from Praeglobotruncana Bermudez 1952 in its umbilical
aperture, umbilical cover-plate, and accessory apertures. It differs from both
Globorotalia Cushman 1927 and Hedbergella Bronnimann & Brown 1958 in the above
mentioned characters, as well as in the constant presence of a single or double keel.

ReMARKS. The confusion surrounding most Globotruncana species has led the
author to split the present forms as much as their morphology and stratigraphical
ranges would allow. No splitting on the basis of minor morphological characters or
of rare specimens has been attempted. This has helped to clarify the nature of each of
the described forms, although further study (serial thin-sectioning and statistical
analysis) may favour the merging of some of these morphologically similar forms.

The present study has shown that the characters of specific value within the genus
Globotruncana are as follows :

1. The shape of the test (biconvex, planoconvex, concavoconvex, sprioconvex
or parallel-sided), which is a function of the relative shapes of both the dorsal
and the ventral sides. Variation within the range of each shape has been
observed, and is not of any taxonomic importance.

2. The character of the keel, whether single or double, or transitional from one to
the other ; and in the double-keeled forms the position of the two keels
relative to each other and to the rest of the test (parallel or divergent,
closely- or widely-spaced, equally- or unequally-developed, marginally
situated or shifted either to the dorsal or the ventral side), which affect the
size, Shape and position of the peripheral band.

3. The shape of the chambers on both the dorsal and ventral sides, the number of
chambers in the test and in the last whorl, as well as the arrangement of the
chambers. This affects the general shape of the test, the shape of its
equatorial periphery (rounded, subrounded, polygonal, entire or lobate) ;
the character of the sutures on both sides of test (straight or curved, raised
or depressed), and the shape of the umbilicus. However, it should be
noted that, other things being equal, variation in any of these characters
separately is not of any taxonomic value.

4. Character of the surface, whether smooth or rough, but not degree of rugosity.

. IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 73

EVOLUTIONARY DEVELOPMENT OF GLOBOTRUNCANA

Although the evolutionary development of the genus Globotruncana has been
discussed by several authors e.g. Reichel (1950), Hagn & Zeil (1954), Gandolfi (1955),
Brénnimann & Brown (1956) and Cita (1963), its origin remains uncertain. However,
the fact that the early part of the test in all representatives of the genus is reminiscent
of Globigerina, led to the belief that the genus had probably evolved from a general-
ized “ Globigerina-like’’ stock. On the other hand, Globigerina, as fixed by the
original designation of its type species (Globigerina bulloides d’Orbigny 1826) is
known to have appeared first at the base of the Danian (i.e. after the disappearance
of the genus Globotruncana), a fact previously recognized by various authors and
confirmed by the present study. This throws doubt on the validity of the previous
records of Globigerina species in Cretaceous and Upper Jurassic rocks. A restudy of
these forms may prove them to be species of Hedbergella, Rugoglobigerina, Prae-
globotruncana, Globotruncana, or other genera. Nevertheless, with the limits of our
present knowledge, the genus Globotrwncana may have originated in one of the
following ways :

1. Praeglobotruncana evolved into Globotruncana by the confinement of the
aperture to an interiomarginal, umbilical position, and by the development
of the umbilical cover-plate ; and Globotruncana in its turn evolved into
Rugoglobigerina by the loss of the keel or keels and by the development of
distinct surface rugosity.

2. Hedbergella evolved in one direction into Praeglobotruncana which continued
its evolution as mentioned above, and in another direction, into Globo-
truncana by the confinement of the aperture to an interiomarginal, umbilical
position, and by the development of both the cover-plate and the keel
(or keels) : Globotruncana, in its turn evolved into Rugoglobigerina by the
loss of the keel or keels and by the development of surface rugosity as
mentioned above.

3. Some of the so-called “ Globigerina’”’ species in the lower part of the Upper
Cretaceous and even in the Lower Cretaceous may possibly belong to
Rugoglobigerina (although the genus has, up till now, been recorded from the
Campanian and Maestrichtian only), but the cover-plate is either broken or
has been lost during the process of fossilization ; hence it can be suggested
that a hypothetical “‘ Rugoglobigerina’’ stock has probably evolved into
Globotruncana by the flattening of the dorsal side and the development of
keel or keels, although Gandolfi (1955) strongly emphasized the fact that
most Globotruncana species had undergone a process of “ globigerinization ”’
to develop into Rugoglobogerina.

?

However, nothing can be decided about the origin of Globotruncana until the
earliest known globigerinid forms have been carefully examined and traced to the
first known Globotruncana species, either directly or indirectly through Hedbergella,
Praeglobotruncana, or Rugoglobigerina.

Several evolutionary trends demonstrated by one or more lineages of the genus
Globotruncana, were suggested by various authors, (e.g. Gandolfi 1955 ; Brénnimann

74 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

& Brown 1956 and Cita 1963). However, the fact that the present study is mainly
concerned with the Maestrichtian Globotruncana, makes it difficult to go into detail,
although the phylogenetic development of each of the species discussed here, is
dealt with in the remarks on each species, and the various lineages suggested in the
present study are summarized in Text-fig. 10. The extension of such lineages
downwards in older strata can only be substantiated by the study of continuous
sections throughout the Upper Cretaceous. Nevertheless, the main evolutionary
tendencies observed in the various Globotruncana species discussed in the present
work can be briefly summarized as follows :

(a) A tendency to reduce the ventral keel.
(b) A tendency to reduce the size of test.
(c) A tendency to increase the surface rugosity.

Again, comparison with the known Globotruncana species in the Turonian, Coni-
acian, Santonian and Campanian, shows that :

1. The tendencies towards reduction of the ventral keel in double-keeled Globo-
truncana, and towards increase in surface rugosity exist throughout the
Upper Cretaceous.

2. A tendency towards the gradual increase in the size of test is clearly documen-
ted ; it reaches its maximum in the Lower Maestrichtian and is then
reversed towards the Upper Maestrichtian.

3. A tendency to increase the height of coiling in spiroconvex forms is observed
from the Turonian throughout the Maestrichtian, and manifests itself in the
flooding of Maestrichtian strata with representatives of the G. contusa
group, G. conica, G. esnehensis, G. sharawnaensis, G. orientalis and G.
fareedt.

4. A tendency, upwards in the section, towards the modification of the shape of
the chambers in the last one or two whorls from globular to ovoid, lenticular,
petaloid, crescentic, trapezoidal, rectangular or even polygonal, although
some of the last representatives still maintain the globular shape of the
chambers. This modification of the chamber shape in the last one or two
whorls affects the general shape of the test and also the shape and size of
the umbilicus.

5. There is a general increase in the number of individuals of each species and in
the number of species and subspecies between the Turonian and the Maes-
trichtian. This is accelerated in the uppermost Cretaceous, and results in
the younger species having a much shorter range than the older ones.

These tendencies, in general, agree well with previous observations by other
authors, especially Bronnimann & Brown (1956), who also noted tendencies towards
the ‘‘refinement of shell material ’’ and towards an increase in the size of the aper-
tural flaps at stratigraphically higher levels. Although exceptions have been noted
to the above-mentioned trends, their existence is in no way invalidated.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 75

Globotruncana adamsi sp. nov.

(Pl. 8, figs. 2a—d.)

Diacnosis. A Globotruncana distinguished by its small to medium-sized, dome-
shaped, distinctly spiroconvex test ; its highly convex dorsal side and almost flat
ventral one ; globigerine, strongly inflated early chambers and crescentic, distinctly
elongated, gently plicate ones in the last whorl ; ovoid, slightly to moderately over-
lapping chambers on ventral side ; two well-developed marginal keels, wide inclined
peripheral band, and generally smooth to delicately papillose surface.

DescriPTion. Test large, spiroconvex, roughly ovoid in outline ; dorsal side
highly convex and moderately inflated ; ventral side almost flat ; equatorial peri-
phery ovoid, slightly lobate, with two well-developed, heavily beaded marginal
keels ; axial periphery truncate, bluntly subangular ; chambers on the dorsal side
not all clear, but apparently 23 in number, arranged in 4 dextrally coiled whorls ;
the initial chambers are small, globular, weakly inflated and increase very slowly in
size ; they are followed by slightly larger, strongly inflated, globular chambers
which increase moderately in size ; the last whorl is composed of 5 large chambers
which increase rapidly in size, and are subglobular and strongly inflated in the early
part, becoming crescentic, strongly elongated in the direction of coiling later ; the
last chamber is weakly plicated ; on the ventral side there are 5 chambers which
increase moderately in size, being subglobular in the early part, ovoid, slightly
inflated and strongly overlapping later ; sutures on the dorsal side slightly curved,
depressed in the early part, strongly curved, raised and distinctly beaded later ; on
the ventral side the sutures are straight, radial, strongly depressed at first, curved
forward, delicately beaded, slightly raised or running in sutural depressions later ;
umbilicus roughly pentagonal in outline, wide, deep, bordered by slightly raised,
delicately beaded umbilical ridges, and covered by complex tegilla of which rem-
nants are still preserved ; primary apertures interiomarginal, umbilical ; tegilla,
with accessory apertures, only poorly preserved ; wall calcareous, perforate except
for the imperforate keels, peripheral band and tegilla ; surface delicately papillose
especially on the ventral side ; the two marginal keels are well-developed and heavily
beaded, the ventral one is slightly shifted towards the ventral side, and thus they
enclose a relatively wide, slightly inclined peripheral band which becomes progres-
sively narrower towards the last chamber.

DIMENSIONS OF HOLOTYPE.

Maximum diameter =" 0°40 mm:
Minimum diameter = 0°36 mm.
Thickness = 0:25 mm. (Across middle part of test)

MAIN VARIATION.

1. Chambers 13-24, arranged in 3-4 whorls, generally dextrally coiled.

2. Chambers in the last whorl 4-6.

3. The two keels are either equally developed or the ventral one slightly weakens
towards the last chamber.

76 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

REMARKS. G. adamsi sp. nov. is morphologically similar to both G. fornicata
fornicata Plummer and G. convexa Sandidge. It is distinguished from the former
by its dome-shaped, distinctly spiroconvex test, and from the latter by its less truncate
axial periphery, better developed marginal keels, and strongly elongated chambers
in the last whorl which overlap more on the ventral side.

Globotruncana adamsi sp. nov. is believed to have evolved from G. fornicata
fornicata Plummer into G. contusa patelliformis Gandolfi, as suggested by the morpho-
logical features and stratigraphical ranges of these three forms. It was probably
confused in the past with G. fornicata Plummer (e.g. Cita 1948) and with G. calici-
formis (de Lapparent) (e.g. Cita 1948, Bolli 1951 and Gandolfi 1955). However,
these forms are not included in the synonymy of the present species as they lack the
distinctly elongated chambers in the last whorl and were incompletely described by
their respective authors.

This species is named after Dr C. G. Adams of the British Museum (Natural
History), London.

HoLotypPe. P.4551T1.
PARATYPES. P.45510.

HORIZON AND LocALITy. Holo- and paratypes from sample No. 4, Abou Saboun
section.

STRATIGRAPHICAL RANGE. The species is common to abundant throughout the
Lower Maestrichtian G. fornicata Zone and the basal part of the Middle Maestrichtian
G. ganssert Zone. It fades out gradually upwards in the section, and dies out comple-
tely in the lower part of the latter zone.

The forms described by Cita (1948) as G. fornicata Plummer and G. caliciformis
(de Lapparent) which may possibly belong to the present species, were recorded from
the Santonian—Maestrichtian and the Upper Campanian—Maestrichtian of Italy
respectively. Similar forms described as G. caliciformis (de Lapparent) by Bolli
(1951) and as G. caliciformis caliciformis (de Lapparent) by Gandolfi (1955) were
recorded from the Maestrichtian of Trinidad and from what was described as Upper
Santonian—Campanian of northeastern Colombia respectively.

Globotruncana aegyptiaca aegyptiaca Nakkady
(PL 3, figs. 4a-d ; Pl. 4, fig. x)

1950 Globotvuncana aegyptiaca Nakkady : 690, pl. 90, figs. 20-22.
?1954 Globotruncana aegyptiaca Nakkady ; Nakkady & Osman : 75-76, pl. 20, figs. 20a~—c.
1956 Rugotyvuncana skewesae Bronnimann & Brown : 550-551, pl. 23, figs. 4-6.

EMENDED DIAGNOSIS. <A Globotruncana distinguished by its medium to large-
sized, distinctly quadrilobate test ; flat to weakly arched dorsal side and strongly
protruding ventral one ; highly lobate equatorial periphery ; two strongly develop-

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 77

ed marginal keels ; curved, raised, beaded dorsal sutures and radial incised ventral
ones ; thick limbate umbilical flange ; very wide umbilicus, and generally rough
surface.

DEscriPTIon. Test large, quadrilobate in outline, planoconvex, umbilicoconvex,
coiled in a very low trochospire ; dorsal side almost flat although the early chambers
are very weakly raised above the circumambient last whorl ; ventral side strongly
inflated and distinctly protruding ; equatorial periphery roughly quadrate, very
distinctly lobate, with two well-developed, much thickened, beaded keels ; axial
periphery truncate ; chambers on the dorsal side 17, arranged in 3 dextrally coiled
whorls ; the initial ones are small, inflated, globigerine, increase slowly in size and are
followed by typically crescentic chambers which increase moderately in size as
added ; the last whorl is composed of 4, large, petaloid chambers which increase so
slowly that they all appear to be equal in size ; on the ventral side the chambers are 4,
large, roughly ovoid, distinctly protruding and increase very slowly in size ; sutures
on the dorsal side are curved, raised, thickened and beaded ; on the ventral side they
are short, radial and depressed ; umbilicus quadrate in outline, very wide, deep,
surrounded by much thickened, limbate, delicately beaded ridges, and covered by
complex tegilla of which remnants are still preserved ; primary apertures interio-
marginal, umbilical ; tegilla with accessory apertures only poorly preserved ;
wall calcareous, perforate except for the imperforate keels, peripheral band and
tegilla ; surface distinctly papillose in the early part, smooth in the later part with
the papillae extremely well developed on the early chambers of the last whorl
especially on the ventral side ; the two marginal keels are almost parallel to each
other and enclose a wide, depressed peripheral band.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter = 0-48 mm.
Minimum diameter == 0:43 mm:
Thickness =| 06:23 mm:

MAIN VARIATION.

I. Chambers 15-19, arranged in 24-3 whorls ; generally dextrally coiled but
sinistral forms also occurr (out of 500 specimens picked at random, 4 coiled
sinistrally).

2. Chambers in the last whorl 4-44, very rarely 5, increasing very slowly in size.

3. Chambers on the dorsal side flat, very weakly inflated, sometimes even
depressed ; on the ventral side the chambers are always strongly inflated.

4. Marginal keels, sutures and umbilical flange either heavily papillose or just
thickened and limbate.

5. The two keels are either equally developed or the ventral keel is sometimes
reduced on the last chamber.

6. Surface delicately papillose in early part, smooth in later part ; sometimes
the papillae are so strongly developed that they give the surface a roughly
nodose, or even spinose appearance. The beads on the marginal keel also
taper out sometimes in the form of spine-like projections.

8 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

“I

REMARKS. Globotruncana aegyptiaca was first validly described by Nakkady
(1950). He had, however, previously (1949) used the name without any description
or figures.

Nakkady (1950) gave only the dorsal view of the holotype, and the ventral and
lateral views of two different paratypes. His choice of the paratype (1950, pl. go,
fig. 22) was rather unfortunate as it is a deformed specimen which does not reflect
the ventral character of the holotype or the other paratypes. He described the
umbilicus as wide, while on his fig. 22 it was shown to be rather narrow. He also
stated that the dorsal side is always flat and that the periphery is “‘ single keeled in
most specimens but occasionally with a double keel ’’. However, examination of the
holotype and paratypes of Nakkady (B.M.N.H.) Nos. P.41773 and P.41774, respec-
tively) showed clearly that all the specimens are double keeled with a rare tendency
towards the reduction of the ventral keel on the last chamber only (e.g. the holotype),
and that the dorsal side is not always perfectly flat, but is sometimes weakly inflated,
giving the test a very gently arched appearance.

Nakkady (1950) described as varieties of G. aegyptiaca two distinct forms which he
named G. aegyptiaca var. duwi and G. aegyptiaca var. I. Examination of the
holotype of G. aegyptvaca var. duwi Nakkady (B.M.N.H. No. P.41775) and 3 para-
types, (P.41776), and comparison with specimens in the present study, showed clearly
that this variety is worthy of distinction as a separate subspecies, in contrast to
Berggren’s (1962) statement that it can probably be included in G. aegyptiaca.
Thus the name is changed here to G. aegyptiaca aegyptiaca to distinguish it from
G. aegyptiaca duwt.

Globotruncana aegyptiaca var. I. Nakkady is a single keeled form which most
probably belongs to the G. ganssevi Bolli group, as previously mentioned by Berggren
(1962) and substantiated by the examination of Nakkady’s holotype and one
paratype (B.M.N.H. Nos. P.41777 and P.41778 respectively).

Berggren (1962) considered G. gagnebini Tilev to be a junior synonym of G.
aegyptiaca Nakkady. However, the study of a great number of individuals of both
species has revealed that they are morphologically distinct. Globotruncana gagne-
bint has a less lobulate, more tightly coiled, distinctly elongate test ; chambers
which increase very rapidly in size, a much larger or much smaller last chamber and a
greater number of chambers in the last whorl.

Nakkady & Osman (1954) recorded G. aegyptiaca aegyptiaca from the Esna shales
and chalk of both the Qabeliat and Sudr sections (southwestern Siani, Egypt),
but their figures are not at all clear.

Bronnimann & Brown (1956) described as Rugotruncana skewesae from the Middle
Maestrichtian of Texas, a form which only differs from the holotype of G. aegyptiaca
aegyptiaca Nakkady in having a distinctly developed spinose periphery, and faint,
discontinuous costellae on the early chambers of the last whorl on the ventral side.
Forms of G. aegyptiaca aegyptiaca with a distinctly spinose periphery and spinose
early chambers on the ventral side were mentioned by Nakkady (1950), were

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 79

observed in his paratypes (B.M.N.H. No. P.41774), and are recorded in the present
study. Brénnimann & Brown 1956 stated that “‘ The distinctive feature of Rugo-
truncana skewesae n. sp. is its very flat dorsal side. Globotruncana concavata (Brotzen)
is the only globotruncanid known to us to have flatter dorsal side.’”” Apart from the
fact that G. concavata has a concave rather than a flat dorsal side, and that there
are at least twenty known Globotruncana species and subspecies with a flat dorsal
side, it is clear from their statement that these authors had completely overlooked
G. aegyptiaca and its related forms which were described at least six years before
their R. skewesae. Moreover, they described the last whorl in R. skewesae as having
5 or 6 chambers, and included in its synonymy forms such as G. rosetta (Carsey) of
Plummer (1927) and G. avca (Cushman) of Jennings (1936) which are actually
G. gagnebili Tilev, thus indicating that they had also included within R. skewesae
forms related to G. gagnebim. However, as the holotype of R. skewesae is identical
with G. aegyptiaca aegyptiaca it is considered to be a junior synonym of the latter.

Said & Kenawy (1956) described as G. aegyptiaca Nakkady, an entirely single-
keeled form which is apparently G. stuarti parva Gandolfi, as mentioned under the
latter species.

The evolutionary history of G. aegyptiaca aegyptiaca is not clearly understood,
although the morphological features of the species may suggest its evolution from
G. ventricosa White through G. gagnebini Tilev and into G. aegyptiaca duwi Nakkady.
However, it is not known whether G. gagnebini appears lower in the section than
G. aegyptiaca aegyptiaca or not, as the two species were always confused with one
another. In the sections studied, both species were found to occur together from
the basal part of the Maestrichtian to the disconformity separating it from the
overlying basal Tertiary. Thus it is not excluded that the two species might have
evolved from two distinct but morphologically similar, forms. If so, the ancestral
stock of G. aegyptiaca aegyptiaca may be sought in a form other than G. ventricosa
White, which is more closely related to G. gagnebini Tilev. Globotruncana tricarinata
colombiana Gandolfi is the only known, morphologically similar Globotruncana
species which appears in older strata, and thus may possibly represent the ancestral
stock from which G. aegyptiaca aegyptiaca has evolved.

HypoTyPes. P.45512-13.

HORIZON AND LOCALITY. Figured specimens from Sample No. 16, Gebel
Owaina section.

STRATIGRAPHICAL RANGE: Nakkady (1950) described G. aegyptiaca aegyptiaca
from the Maestrichtian Esna shale of the Abu Durba section, western Sinai, Egypt,
and recorded it as rare to abundant in the chalk of W. Mellaha (Eastern Desert),
the shale of W. Danili (western Sinai), and frequent to abundant in the chalk of
G. Duwi (Eastern Desert), Egypt. The species was also recorded from the Camp-
anian—Maestrichtian of both the Qabeliat and Sudr sections, Sinai, Egypt (Nakkady
& Osman 1954), and as R. skewesae from the Middle Maestrichtian of the Navarro
group of Texas, (Bronnimann & Brown 1956).

80 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

In the Esna—Idfu region, G. aegyptiaca aegyptiaca floods the whole of the Maestrich-
tian section, being extremely abundant in the G. fornicata and G. gansseri Zones,
fading out gradually in the top part of the overlying G. esnehensis Zone, and dying
out completely just below the disconformity separating the Maestrichtian from the
overlying Paleocene.

Globotruncana aegyptiaca duwi Nakkady

(Pl. 3, figs. 5a—c)
1950 Globotyuncana aegyptiaca Nakkady var. duwi Nakkady : 690, pl. go, figs. 17-19.
1954 Globotrvuncana aegyptiaca var. duwi Nakkady : Nakkady & Osman : 76, pl. 20, figs. 2ta—c.

EMENDED DIAGNOSIS: A Globotruncana aegyptiaca with much smaller test
and fewer chambers increasing very rapidly in size in last whorl ; ovoid to subtriangu-
lar, slightly lobate periphery, and rougher surface.

DESCRIPTION. Test medium-sized, roughly ovoid in outline, planoconvex,
umbilicoconvex, coiled in a very low trochospire ; dorsal side almost flat, ventral side
distinctly protruding ; equatorial periphery roughly ovoid, moderately lobate,
with two well-developed, beaded keels ; axial periphery truncate ; chambers on
the dorsal side, 11, arranged in 2 dextrally coiled whorls ; the initial chambers are
small, globigerine, inflated, almost masked by the surface rugosity and increase
slowly in size ; the last whorl is composed of 4 chambers which increase so rapidly
in size that the last one constitutes about half of the test ; on the ventral side the
chambers are 4, large, strongly inflated, distinctly protruding and increase very
rapidly in size ; sutures on the dorsal side are curved, raised and beaded ; on the
ventral side they are slightly curved forward, depressed and beaded ; umbilicus
roughly quadrate in outline, relatively wide, deep, bordered by thick, raised, beaded
ridges and covered by complex tegilla of which remnants are still preserved ;
primary apertures interiomarginal, umbilical ; tegilla with accessory apertures only
poorly preserved ; wall calcareous, perforate except for the imperforate keels,
peripheral band and tegilla ; surface rough, distinctly papillose and spinose in the
early part, with the roughness decreasing gradually towards the last chamber ; the
two marginal keels are almost parallel to each other and enclose a wide, depressed,
slightly inclined peripheral band.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter =, O-40.mm.
Minimum diameter = 0:30 mm.
Thickness —= 0-22 Tia.

REMARKS. Globotruncana aegyptiaca duwi was first described by Nakkady (1950)
as a variety of G. aegyptiaca. However, the present study has shown that it is
morphologically distinct from G. aegyptiaca aegyptiaca and that it appears in strati-
graphically younger strata. Thus it is here raised to subspecific rank, although
Berggren (1962) stated that it can probably be included in G. aegyptiaca s.s._ Globo-

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 81

truncana aegyptiaca duwt is believed to have evolved from G. aegyptiaca aegyptiaca as
suggested by their morphological features and stratigraphical distribution.

Gandolfi (1955 : 21, 22 ; text-fig. 5, 2a—c) included in his G. tvicarinata colombiana,
a form which possibly belongs to G. aegyptiaca duwt.

HypotyPe. P.45514.

HorRIzoN AND LOCALITY. Figured specimen from sample No. 16, Gebel Owaina
section.

STRATIGRAPHICAL RANGE. Nakkady (1950) described G. aegyptiaca duwi from
the Upper Cretaceous chalk of Gebel. Duwi section, Kossier area, Eastern Desert,
Egypt, where it was described as rather frequent. It was also recorded from the
Campanian—Maestrichtian of southern and western Sinai, Egypt (Nakkady & Osman
1954) and from the Maestrichtian of Um El-Huetat section, Eastern Desert, Egypt
(Ansary & Fakhr 1958).

In the Esna-Idfu region, G. aegyptiaca duwi appears in the basal part of the
G. gansseri Zone, and increases gradually in number upwards in the section becoming
abundant in the upper part of this zone, and then fades out gradually, dying out
completely at the top of the overlying G. esnehensis Zone.

Globotruncana arabica sp. nov.

(Pl. 6, figs. 3a—-d ; Pl. 11, fig. 4)

Diacnosis. <A Globotruncana with large, concavo-convex, strongly umbilico-
convex test ; entirely single keel strongly shifted towards dorsal side ; chambers
increasing slowly in size and distinctly inflated on ventral side ; very rough surface
and large umbilicus.

DEscriPTION. Test large, subcircular, globular in outline, concavo-convex,
distinctly umbilico-convex, coiled in a very low trochospire ; dorsal side shallowly
concave, flat in the early part, slightly tilted inward in the last whorl ; ventral side
strongly inflated and distinctly protruding ; equatorial periphery subcircular,
globular and distinctly lobate, with a single, well developed, beaded keel which is
strongly shifted towards the dorsal side ; axial periphery subrounded, very gently
truncate ; chambers on the dorsal side about 17, arranged in 3 dextrally coiled
whorls ; the initial chambers are small, globular, weakly inflated, almost masked by
the surface rugosity and are followed by slightly larger, subglobular, weakly inflated
ones ; the last whorl is composed of 5 large, subglobular, compressed chambers
which increase slowly in size, are slightly elongated in the direction of coiling and
strongly tilted inward towards the initial part ; on the ventral side the chambers are
5, large, subglobular, strongly inflated, distinctly protruding, and enlarging so slowly
that they all appear roughly equal in size ; sutures on the dorsal side are slightly
curved, depressed in the early part, very short, slightly curved to almost straight in
the later part, raised and beaded on the periphery, becoming depressed inward ; on
the ventral side the sutures are straight, radial, and strongly depressed ; owing to the

82 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

inward tilting of the dorsal surface of the last whorl the junction between the ventral
and dorsal sutures can be seen from the the dorsal side ; umbilicus pentagonal in out-
line, wide, deep, and covered by complex tegilla of which remnants are still preserved ;
primary apertures interiomarginal, umbilical ; tegilla with accessory apertures only
poorly preserved ; wall calcareous, perforate, except for the imperforate keel and
tegilla ; surface rough, heavily papillose or even nodose, especially in the early part
with the roughness decreasing gradually towards the last chamber ; the single
marginal keel is distinctly beaded, with the beads slightly fading out on the penulti-
mate and last chambers ; the keel of each chamber encircles its periphery and then
disappears into the short, depressed, dorsal sutures ; the umbilicus is not bordered
by a flange of any sort, although the large, scattered beads on the surface may
simulate a beaded rim.

DIMENSIONS OF HOLOTYPE.

Maximum diameter == 0°54: min.
Minimum diameter = (0-42 mim:
Maximum thickness = 0-34 mm. (Thickness of last chamber)
Minimum thickness = 0:23 mm. (Across middle part of test)

MAIN VARIATION.

1. Chambers on the dorsal side 13-18, most commonly 15, arranged in 24-3
whorls, generally dextrally coiled.

2. Chambers in the last whorl 44-6, slowly to moderately increasing in size.

REMARKS : Globotruncana arabica sp. nov. is distinguished by its large, concavo-
convex, strongly umbilico-convex, single keeled test, its large umbilicus and rough
surface. The only known Globotruncana species with a concavo-convex, umbilico-
convex test are : G. concavata (Brotzen) 1934, from the Campanian—Santonian of
Palestine, G. vepanda Bolli 1957, from the Campanian of Trinidad, and G. bahijae
sp. nov. from the Maestrichtian of the Esna—Idfu region. The first species is
distinguished from G. arabica by its closely spaced double keel, less concave dorsal
side, chambers which increase more rapidly in size, and by its smooth surface. The
second is differentiated by its smaller test, fewer number of chambers, double keel
in the early part (which may be absent in the penultimate and last chambers),
much smaller early part, and less rugose surface. The third is distinguished by its
less protruding ventral side and its double keel. Globotruncana arabica sp. nov.
is morphologically closely related to G. repanda Bolli. Small specimens of G. arabica
resemble G. vepanda, but differ in having an entirely single keel, and chambers
which increase slowly in size. By reduction of the ventral keel and increase in the
size of test, in the number of chambers and in the surface rugosity, G. repbanda might
possibly have evolved into G. arabica. Such tendencies are clearly recorded in
G. repanda, but the latter species is known to die out completely in the Upper Cam-
panian, while G. arabica is only recorded from the Middle and Upper Maestrichtian.
Thus it is suggested that G. arabica either evolved from a yet undescribed form,
transitional between it and G. vepanda, or that the latter also occurs in the Lower
Maestrichtian, but has not yet been found.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 83

Globotruncana arabica sp. nov. is also morphologically related to G. lugeoni Tilev
and G. youssefi sp. nov. which occur in association with it. It is distinguished from
the former by its larger test, its strongly shifted keel towards the dorsal side, its
shorter, less curved, depressed dorsal sutures and its much wider umbilicus. It
differs from the latter by the fact that G. youssefi has an almost flat dorsal side, or
even slightly raised initial part, longer, more curved, raised and beaded dorsal
sutures and a truly marginal keel.

HOLoTyPeE. P.45515.
PARATYPES. P.45510.

HORIZON AND LocaALiTy. Holo- and paratypes from sample No. 22, W. EI-
Sharawna section.

STRATIGRAPHICAL RANGE. The species appears for the first time in the upper
part of the Middle Maestrichtian G. gansseri Zone. It increases in number upwards
in the section until it floods the uppermost part of this zone and the basal part of the
overlying G. esnehensis Zone before dying out completely in the middle part of the
latter zone.

Globotruncana arca (Cushman)
(Pl. 1, figs. 1a—z2)

1926a Pulvinulina avca Cushman : 23, pl. 3, figs. 2a—c.

1927a Globotyvuncana avca (Cushman) Cushman : 91, pl. 19, figs. 11a—c.

1937a Globotruncana ayvca (Cushman) ; Glaessner : 36, pl. 1, figs. 1oa—c.

1946 Globotruncana avca (Cushman) ; Cushman (pars) : 150, pl. 62, figs. 4a—c (non figs. 5a—c).

1951 Globotruncana avca (Cushman) ; Bandy : 509, pl. 75, figs. Ia—c.

1951 Globotruncana avca (Cushman) ; Noth: 77, pl. 8, figs. 15a-—c.

1951a Globotruncana arca (Cushman) ; Nakkady (pars) : 56, pl. 1, figs. 4B—E, non fig. 4A.

1951 Globotruncana arca (Cushman); Tilev: 57, text-figs. 18a—d, 19a—-d. (See also Tilev
1952, where figures are repeated.)

1953 Globotruncana avca (Cushman) ; Hagn: 97, pl. 8, figs. 11a—c, text-figs. 20, 21.

1953 Globotruncana avca (Cushman) ; Subbotina: pp. 185-188, pl. 9, figs. ra—5c, pl. Io,

figs. Ia—5c.
1955 Globotyuncana arca avca (Cushman) ; Gandolfi (pars) : 63, pl. 5, figs. 3a-c ; non figs.
2a-C, 4a-c.

1956 Globotyuncana avca (Cushman) ; Bronnimann & Brown: 539, pl. 23, figs. Io-12.

1957 Globotruncana (Globotruncana) avca (Cushman) ; Edgell (pars) : 110, pl. 3, figs. 4-6 ;
non pl. 1, figs. 10-12.

1957 Globotruncana avca (Cushman) ; Bolli, Loeblich & Tappan: 44, pl. 11, figs. 6—11c.

1958 Globotruncana avca (Cushman) ; Bieda : 60, text-fig. 24.

1960 Globotyuncana avca (Cushman) ; Vinogradov : 313, pl. 5, figs. 27a-c.

1962 Globotruncana ayca (Cushman) ; Barr: 567, pl. 69, figs. 8a—c.

EMENDED DIAGNOSIS. A Globotruncana with large, robust, biconvex test ;
great number of chambers per test and in last whorl ; two well-developed, much
thickened beaded keels ; wide, inclined peripheral band ; curved, much thickened,
raised, beaded sutures ; distinct, horseshoe-shaped ridge of beads outlining each
chamber on ventral side ; wide umbilicus.

84 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

DEscRIPTION. (Pl. I, figs. Ia—c). Test large, robust, unequally biconvex, coiled
in a relatively high trochospire ; dorsal side convex, broadly arched, ventral side
moderately inflated, slightly protruding ; equatorial periphery subcircular, moder-
ately lobate ; axial periphery angular, slightly truncate, with two well-developed,
strongly thickened marginal keels ; chambers on the dorsal side 22, arranged in 34
dextrally coiled whorls ; the initial ones are small, inflated, globigerine, increase very
slowly in size and are followed by typically crescentic chambers ; the last whorl is
composed of 7 (6+1 abortive), large, typically crescentic chambers (except for the
fourth and fifth) which increase slowly in size ; on the ventral side these chambers
are subglobular to ovoid, moderately inflated, sharply outlined by distinctly thicken-
ed horseshoe-shaped ridges ; sutures on the dorsal side curved, raised, thickened and
beaded except on both sides of the antepenultimate chamber where they tend to be
almost straight ; on the ventral side the sutures are short, thickened, raised, beaded
and slightly curved forward ; umbilicus roughly hexagonal in outline, wide, deep,
surrounded by raised ridges and covered by complex tegilla of which remnants are
still preserved ; primary apertures interiomarginal, umbilical ; tegilla with accessory
apertures only poorly preserved ; wall calcareous, perforate except for the imperfo-
rate keels, peripheral band and tegilla ; surface smooth except for a few small,
scattered papillae ; the two subparallel keels are well-developed, limbate and beaded,
they enclose a relatively wide, depressed, inclined peripheral band except on the last
chamber where the two keels become closer to each other ; the dorsal keel is more
developed and strongly protruding while the ventral keel is slightly shifted towards
the inner part of test.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter = 052 mm.
Minimum diameter == 0:46 mm.
Thickness =) (0-27 mine

MAIN VARIATION.

1. Chambers on the dorsal side 18-24, arranged in 3—4 whorls, generally dextrally
coiled.

2. The last whorl is composed of 5-8 chambers, but 6-7 is most common.

REMARKS : Globotruncana arca (Cushman) was first described by Cushman (1926)
as Pulvinulina arcan.sp. He later (1927) erected Globotruncana as a new genus, with
Pulvinulina arca Cushman 1926, as type species.

Plummer (1931) described as G. arca, double- and single-keeled forms which
differ from Cushman’s original description and figures. Bronnimann & Brown
(1956 : 450) stated that ‘‘ Her two-keeled forms are specimens of Git. cretacea
Cushman which is an incipient Gilt. rosetta (Carsey). Her one-keeled forms are
actually double-keeled, but the two keels are very close together ; they are well-
developed specimens of Git. rosetta.”

Cushman (1932) described as G. arca, a planoconvex, single-keeled form, and in
1946 he presented the figures of the holotype and of this form as G. arca. Cita (1948)

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 85

interpreted Cushman’s single-keeled form as G. rosetta (Carsey), while Bolli (1951)
stated that it probably belongs to the Globotruncana stuarti group. Gandolfi (1955)
made this form the basis of a new species which he named Globotruncana bollit,
while Dalbiez (1955) considered it to belong to his subspecies G. elevata stuartiformis
Dalbiez, | =G. stwarti stuartiformis Dalbiez].

Gandolfi (1955) described Globotruncana arca caribica as a new subspecies of
G. arca (Cushman) and thus changed the latter’s name to G. arca arca (Cushman).
However, G. arca caribica appears to be a junior synonym of G. gagnebini Tilev 1951,
thus the name G. arca (Cushman) is here retained. Similarly, Said & Kerdany (1961)
described as G. avca (Cushman) from the Maestrichtian chalk of the Farafra Oasis,
Egypt, a form which probably belongs to G. gagnebini Tilev.

Globotruncana arca (Cushman) is believed to have evolved from the G. linneiana
(d’Orbigny) (=G. lapparenti Brotzen) stock as previously mentioned by Cita (1948),
Bolli (1951), Bronnimann & Brown (1956) and Berggren (1962). On the other hand,
G. arca was itself found to show three main evolutionary tendencies which are as
follows :

1. A tendency towards the reduction of the ventral keel on the final chambers

leading to G. lewpoldi Bolli.

2. A tendency towards the flattening of the ventral side and the reduction of the

ventral keel leading to G. orientalis sp. nov.

3. A tendency to reduce the size of test and the number of chambers in the last

whorl leading to G. convexa Sandidge. (see Pl. 1, figs. 3a-c.)

The morphological characters and stratigraphical ranges of the five species
(G. linneiana, G. arca,G. leupoldt, G. orientalis and G. convexa) support this hypothesis.

Hypotyres. P.45517.

HORIZON AND LOCALITY. Figured specimens PI. 1 figs. ta—c, 2, from sample No. 4,
Abou Saboun section, and figs. 3a—-c, from sample No. 23, W. El-Sharawna section.

STRATIGRAPHICAL RANGE: The species was first described from the upper part
of the Papagallos shales (Mendez shale) of Mexico which was later considered to be of
Maestrichtian age.

Analysis of all previous records of G. arca (Cushman) shows that it has a world-wide
distribution, and that it occurs mainly in the Maestrichtian and the uppermost
Campanian. However, owing to misidentification of the species and confusion with
various other species, its true stratigraphical range has hitherto been obscured.
Bronnimann & Brown (1956) stated that G. avca appears to be restricted to Maestrich-
tian strata and that all occurrences reported from pre-Maestrichtian strata are
probably erroneous. They added that it is best developed in Upper Maestrichtian
strata, and this was partially substantiated by Berggren (1962 : 51). However,
G. arca was recorded by Barr (1962) from the uppermost part of the Belemnitella
mucronata Zone of the Isle of Wight, England, and from the Upper Campanian of the
Paris Basin by the present author.

86 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

In the Esna—Idfu region G. avca occurs as an abundant form in the G. forncatai
Zone and in the lower part of the overlying G. gansservi Zone. It fades out gradually
in the upper part of the latter zone, and dies out completely before the overlying
G. esnehensis Zone.

Globotruncana bahijae sp. nov.
(Pl. 6, figs. 2a—d)

Diacnosis. A Globotruncana with concavo-convex test, weakly developed
double keel, wide peripheral band, rough surface and very wide umbilicus.

DEscRIPTION. Test large, roughly ovoid in outline, concavo-convex, coiled in
a very low trochospire ; dorsal side gently concave with the early whorls depressed
and the last chambers slightly sloping towards the central part of test, ventral side
inflated and moderately protruding ; equatorial periphery roughly ovoid, moderately
lobate with two widely spaced, delicately beaded marginal keels which are slightly
masked by the surface rugosity ; axial periphery subrounded, subtruncate ; chambers
on the dorsal side 15, arranged in 2} dextrally coiled whorls ; the initial chambers are
small, weakly inflated, globigerine, and increase slowly in size ; they are followed by
relatively large, subglobular, compressed chambers which increase slightly more
rapidly in size ; the last whorl is composed of 53 large, crescentic, compressed
chambers which are slightly tilted towards the central part and increase slowly in
size ; on the ventral side the chambers are 53, subglobular, slightly elongated in the
direction of coiling, strongly inflated, moderately protruding, very loosely coiled and
increase slowly in size ; sutures on the dorsal side slightly curved, depressed in the
early part, strongly curved, raised and delicately beaded in the last whorl ; on the
ventral side the sutures are straight, radial and strongly incised ; umbilicus hexago-
nal in outline, very wide, relatively shallow, covered by complex tegilla ; primary
apertures interiomarginal, umbilical ; tegilla, with accessory apertures, reasonably
well-preserved ; wall calcareous, perforate except for the imperforate keels, peripheral
band and tegilla ; surface rough, covered with large papillae which are slightly
reduced towards the last chamber ; the two marginal keels are delicately beaded, the
dorsal one is alwayswell-developed but theventral is sometimes almost masked bythe
surface rugosity ; the two keels slightly diverge from each other and enclose an
irregular, relatively wide peripheral band.

DIMENSIONS OF HOLOTYPE.

Maximum diameter = O45 min
Minimum diameter =— 50°32 tii.
Thickness = 0:20 mm. (of last chamber)

MAIN VARIATION

1. Chambers on the dorsal side 13-18, arranged in 2}—3 whorls, usually dextrally
coiled, but sinistral forms occasionally occur (of 67 specimens picked at
random, I coiled sinistrally).

2. Chambers in the last whorl 5-7 increasing slowly to moderately in size.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 87

REMARKS. Globotruncana bahijae sp. nov. is morphologically rather similar to each
of the following Globotruncana species, all of which, except the last, appear in
stratigraphically older strata :

1. Globotruncana concavata (Brotzen).

2. Globotruncana fundiconulosa Subbotina.

3. Globotruncana (Rugoglobigerina) pennyi sunpennyi Gandolfi.

4. Globotruncana repanda Bolli.

5. Globotruncana arabica sp. nov.

However, it is distinguished from G. concavata (Brotzen) by its more concave
dorsal side and less protruding ventral one, widely spaced keels, chambers which
increase less rapidly in size and rough surface.

It differs from G. fundiconulosa Subbotina in its more concave dorsal side, less
strongly developed marginal keels, chambers which increase more rapidly in size
and radial depressed ventral sutures.

It is more closely related to the form described by Gandolfi (1955) as G. (Rugo-
globigerina) penny subpennyt, but differs from it in its concave dorsal side and less
protruding ventral one and by its widely spaced marginal keels. It might possibly
have evolved from the latter subspecies which appears to be a true Globotruncana
(not a Rugoglobigerina), although Gandolfi’s description does not allow a definite
decision.

Globotruncana bahyae sp. nov. is distinguished from both G. vepanda Bolli and
G. arabica sp. nov. by its compressed test, less protruding ventral side, greater
number of chambers and widely spaced keels.

HototyPe. P.45518.
PARATYPES. P.45519.

HORIZON AND LOCALITY. Holo- and paratypes from sample No.18 W. El-Sharawna
section.

STRATIGRAPHICAL RANGE. The species appears for the first time in the middle
part of the Middle Maestrichtian G. gansseri Zone. It increases in number upwards
in the section to flood the upper part of the latter zone and then fades out gradually,
disappearing completely before the overlying G. esnehensis Zone.

Globotruncana conica White
(Pl. 12, figs. 2a—d)

1928b Globotruncana conica White : 285, pl. 38, figs. 7a~-c.
?1950 Globotruncana (Globotruncana) sp. aff. conica White ; Reichel : 614, text fig. 7b.
21951 Globotruncana conica White; Tilev: 67, figs. 22a-d. (See also Tilev 1952 where
figures are repeated.)
1956 Globotruncana conica White ; Said & Kenawy : 150, pl. 5, figs. 16a-—c.

88 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

EMENDED DIAGNOSIS. A_ Globotruncana with large, broadly conical test ;
almost circular slightly lobate equatorial periphery, and angular to subangular axial
one ; entirely single keel ; broadly conical dorsal side and flat to slightly concave
ventral one ; numerous chambers and whorls, and large number of chambers in
last whorl ; globigerine initial chambers and subcircular to crescentic intermediate
ones, which become roughly rectangular in last whorl ; raised, beaded, almost
straight dorsal sutures, and curved, depressed ventral ones ; ovoid overlapping
chambers on ventral side and wide deep umbilicus.

DEscrRIPTION. Test large, broadly conical ; dorsal side highly raised, with the
various whorls arranged in the form of a cone with a rather sharp apex and a very
broad base ; ventral side flat although the chambers are slightly inflated ; equatorial
periphery almost circular, slightly lobate with a single, well-developed, beaded keel ;
axial periphery subangular ; chambers on the dorsal side 24, arranged in 4 dextrally
coiled whorls ; the initial chambers are very small, slightly inflated, globigerine and
are followed by relatively larger chambers which are crescentic to semicircular and
increase moderately in size ; the last whorl is composed of 6 large, roughly rectangular
chambers which are elongated in the direction of coiling and increase slowly in size ;
on the ventral side the chambers are 6, roughly ovoid to subcircular, slightly elonga-
ted, moderately inflated and overlapping especially in the later part ; sutures on the
dorsal side slightly curved in the early part, almost straight and angular later,
distinctly raised, thickened and beaded ; on the ventral side the sutures are depressed,
generally curved forward in the later part, tending to be nearly radial in the early
part, beaded and running in sutural depressions formed by the slight inflation of the
chambers ; umbilicus circular, relatively wide, deep, surrounded by slightly raised,
beaded ridges and covered by complex tegilla of which remnants are still preserved ;
primary apertures interiomarginal, umbilical ; tegilla with accessory apertures only
poorly preserved ; wall calcareous, perforate except for the imperforate keel and
tegilla ; surface smooth.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter = 0°51 mm.
Minimum diameter = 0-48.4mm.
Thickness == 0°20 iim.

MAIN VARIATION.

1. Chambers 21-24, arranged in 3-4 whorls generally dextrally coiled (all
studied specimens coiled dextrally).

2. Chambers in the last whorl 6-7, rarely 8.

REMARKS. Globotruncana conica was first described by White (1928), but his
description was so short and incomplete that the species has often been misidentified,
and its morphological characters and stratigraphical range much confused. The
short description led most of the following authors to describe any Globotruncana
species with a convex dorsal side and a flat ventral one as G. conica White. Asa
result, most of the existing figures are inadequate and most authors tend to speak of
G. cf. conica White, rather than G. conica White.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 89

Glaessner (1937a) and Keller (1946) described as G cf. conica White and G. conica
White respectively, forms which possibly belong to G. contusa Cushman. The
form described by Cushman & Renz (1947) as G. comica is doubtful, while that
described by Cita (1948) can probably be assigned to G. orientalis sp. nov. Again, the
form described by Bolli (1951) as G. conica White is probably G. stuarti stuart
(de Lapparent).

Tilev (1951, 1952) described as G. conica White, a form with only 53 chambers in
the last whorl, and distinctly outlined chambers on the ventral side. This form is
questionably related to the present species. However, the fact that Tilev included
in the synonymy of his G. conica, forms such as G. conica var. plicata White and G.
linnei caliciformis (de Lapparent), which are probably synonymous with G. contusa
contusa (Cushman) and G. contusa patelliformis Gandolfi respectively, throws doubt
on the identification of his specimens. Tilev also described as G. conica-calicifornus
nom. nov., a form which he considered as transitional between G. conica White and
G. caliciformis (de Lapparent). However, as mentioned above, G. caliciformis is a
probable synonym of G. contusa (Cushman), a species which is morphologically
distinct from G. conica. This intermediate form described by Tilev may belong to
G. orientalis sp. nov.

Subbotina (1953) described as G. conica White, forms which are G. contusa scutilla
Gandolfi and G. contusa patelliformis Gandolf..

Gandolfi (1955) considered G. conica White as a subspecies of G. stwarti (de Lap-
parent), and thus changed its name to G. stwartt conica (White). However, as
mentioned under G. stwarti stuarti, the morphological characters and stratigraphical
ranges of the two species warrant their separation. Moreover, the form described by
Gandolfi (1955) is different from both the holotype of White and the known forms of
G. stuarvti, and should be renamed and redescribed in more detail. Following
Gandolfi (1955), Said & Kenawy (1956) incorrectly emphasized the relationship
between G. conica White and G. stwarti (de Lapparent).

Pessagno (1960, 1962) described as G. conica White, forms which were said to
have a double keel on the early chambers of the last whorl, giving way to a single
keel on the following chambers. Such forms probably belong to G. orientalis sp. nov.

Globotruncana comca White is unique among the known spiroconvex Globotruncana
species. No morphologically similar forms have yet been recorded from older strata,
and thus very little is known about the evolutionary history of the species. However,
it is possible that G. conica evolved from either G. sharawnaensis sp. nov. or
G. orientalis sp. nov. The confused stratigraphical range of the species makes it
difficult to decide, for the time being, although forms of G. shavawnaensis with an
entirely single keel appear closely similar to G. conica.

HypotypPe. P.45520.

HORIZON AND LOCALITY. Figured specimen from sample No. 16, Gebel Owaian
section.

go UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

STRATIGRAPHICAL RANGE. White (1928) described G. conica from the Maestrich-
tian Mendez formation of Mexico. However, he stated that the species ranges from
the lower to the uppermost Cretaceous (Tamaulipas—Mendez formations) of Mexico,
which is rather strange, as most of these Globotruncana species have very short
ranges. Apparently he had confused the species with superficially similar Globo-
truncana and Praeglobotruncana species which occur in older strata. Globotruncana
conica was later described from the Middle and Upper Maestrichtian of S.E. Turkey
(Tilev 1952) and form the Maestrichtian of northern Sinai, Egypt (Said & Kenawy
19560). It was also stated to occur in the Maestrichtian of northern Italy (Cita 1948,
1955, and Bolli & Cita 1960a) ; from the Upper Santonian—Lower Campanian of
Trinidad (Bolli 1957, where the same author also recorded a form he described as
G. cf. conica White in the Campanian—Maestrichtian of the same area) ; and from the
upper part of the Mendez shale of Mexico (Hay 1960).

In the Esna—Idfu region G. conica White is rare to common in the Middle Maestrich-
tian G. ganssert Zone.

Globotruncana contusa contusa (Cushman)
(Pl. 7, figs. 2a—3c, Pl. 11, figs. 1a, b)

1926a Pulvinulina avca Cushman var. contusa Cushman : 23 (no figs.).

1927a Globotvuncana avca Cushman var. contusa (Cushman) ; Cushman: 169 (no figs.).

1939 Globotvuncana ayca (Cushman) var. contusa (Cushman) ; Morozova : 8o, pl. 1, figs. 1-3.

1946 Globotvuncana arca (Cushman) var. contusa (Cushman) ; Cushman: 150-151, pl. 62,
figs. 6a—b.

1946 Globotyuncana conica White ; Keller : 102-103, pl. 3, figs. 4, 5.

1948 Globotvuncana ayca (Cushman) var. contusa (Cushman) ; Di Napoli: 21-22, text-figs.
2a-C.

1951 Globotyuncana (Globotruncana) contusa (Cushman) ; Noth: 79, pl. 8, figs. 17a-c.

1951 Globotvuncana contusa (Cushman) ; Bolli: 196, pl. 34, figs. 7-9, text-fig. rf.

1953 Globotruncana contusa (Cushman) ; Subbotina (pars) : 192-194, pl. 2, figs. 3a-c ;
pl. 12, figs. 2a—c (non figs. 1a—c).

1954 Globotruncana contusa (Cushman) ; Nakkady & Osman : 78-79, text-figs. Aa-c.

1955 Globotyuncana contusa contusa (Cushman) ; Gandolfi: 53, pl. 4, figs. 3a—c.

1956 Globotruncana contusa (Cushman) ; Wicher : 136, pl. 12, figs. 5, 6.

1956a Marginotyvuncana contusa (Cushman) Hofker : 53, text-fig. 9.

1960a Globotruncana (Marginotruncana) contusa (Cushman) ; Hofker : 225, text-figs. 22a-c.

1960e Globotruncana contusa (Cushman) ; Hofker : 586, text-fig. 1, drawing No. 15.

1960 Globotyuncana contusa (Cushman) ; Olsson : 50, pl. ro, figs. 25, 26.

1960 Globotyuncana contusa (Cushman) ; Vinogradov: 311, pl. 4, figs. 23a-24c; pl. 5,
figs. 25a-c.

1962 Globotruncana (Marginotruncana) contusa (Cushman) ; Hofker : 1062, text-fig. 7A.

~~

vu

~~

~w

EMENDED DIAGNOSIS. A Globotruncana with large highly spiroconvex test,
distinctly folded surface, roughly angular, polygonal periphery, flat to slightly
concave ventral side, sharply cut rectangular chambers on ventral side, radial,
depressed ventral sutures, two well-developed marginal keels and almost horizontal
peripheral band.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT QI

DESCRIPTION. (Specimen, Pl. 7, figs. 2a—c). Test large, robust, spiroconvex with
a sharply angular, polygonal outline and a peculiarly shaped, folded surface ;
dorsal side highly trochospirally coiled, with bluntly curved convex folds radiating
from the apex and shallowly concave, broader depressions running between the
radiating folds, and widening away towards the base ; ventral side concave ;
equatorial periphery roughly pentagonal with blunt corners, gently undulating and
very weakly, if at all, lobate ; periphery with two well-developed, heavily beaded
keels, enclosing a relatively wide, almost horizontal, slightly depressed peripheral
band ; axial periphery subangular, distinctly truncate ; chambers, on the dorsal
side 23, arranged in 4 dextrally coiled whorls ; they increase moderately and regu-
larly in size till shortly before the beginning of the last whorl where they start to
enlarge very rapidly and to change in shape ; the initial chambers are small, inflated,
globigerine ; they increase moderately in size and are followed by relatively large,
globular, inflated chambers which increase more rapidly in size, and become highly
undulating and strongly elongated in the direction of coiling towards the end of the
penultimate whorl ; the last whorl is composed of 4, very long, very narrow,
broadly curved, roughly oblong, undulating chambers which are extremely elongated
in the direction of coiling ; on the ventral side the chambers are 4, very large,
angular, roughly oblong, very narrow, strongly elongated in the direction of coiling
with their surfaces gently sloping towards the umbilicus ; sutures on the dorsal side
slightly curved, faintly raised and delicately beaded in the early part, strongly
curved, undulating, raised, thickened and heavily beaded later ; on the ventral side
the sutures are straight, radial and depressed ; umbilicus rhombodial in outline,
relatively wide, deep, surrounded by beaded umbilical ridges and covered by complex
tegilla of which remnants are still preserved ; primary apertures interiomarginal,
umbilical ; tegilla, with accessory apertures, only poorly preserved ; wall calcareous,
perforate except for the imperforate keels, peripheral band and tegilla ; surface
delicately papillose especially on the early part and on the ventral side.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter —=\.0-70 Tana.
Minimum diameter = 0°50 mm.
Thickness —S10"45 am,

MAIN VARIATION.

I. Chambers 16-25, arranged in 3-4 or rarely 5 whorls, usually dextrally coiled,
but sinistral forms also occur (out of 25 specimens picked at random, I
coiled sinistrally).

2. Chambers in the last whorl 4-5.

3. The two keels are either equally developed throughout or the ventral one
becomes slightly reduced on the last chamber.

REMARKS. Globotruncana contusa contusa was first described by Cushman (1926)
as a variety of Pulvinulina arca Cushman = Globotruncana arca (Cushman), but
no figures were given until 1946, when Cushman figured the dorsal and lateral views
of the holotype.

92 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

Glaessner (1937a@) raised Cushman’s variety to specific rank, but again gave no
figures. He was followed by Cita (1948), Bolli (1951), Noth (1951), Subbotina
(1953), Ayala (1954), Nakkady & Osman (1954) and Troelsen (1955), but the figures
given by both the first and last authors are different from Cushman’s holotype.

Gandolfi (1955) described two new subspecies of G. contusa (Cushman) and thus
changed its name to G. contusa contusa, to distinguish it from G. contusa patelliformis
Gandolfi and G. contusa scutilla Gandolfi. Hofker (1956a, 1960a, 1962a) assigned
the present from to his genus Marginotruncana which is a junior synonym of Globo-
truncana as stated above. Globotruncana conica var. plicata White 1928 is probably
a junior synonym of G. contusa contusa (Cushman), but White’s brief description does
not allow a definite decision without examination of his holotype. Similarly,
comparison of oriented thin sections of G. contusa (Cushman) with the holotype
of Rosalina linnei mut. caliciforme de Lapparent 1918, and with Globotruncana linner
caliciformis (de Lapparent) of Vogler (1941), showed the possibility that G. contusa
(Cushman) 1926 may be a junior synonym of G. caliciformis (de Lapparent) 1918.
However, examination of several samples from the type locality of de Lapparent
(The Hendaye region of southwestern France) is needed before any decision can be
taken, as his original description is very brief, and his figure is only of a thin section.
On the other hand, forms described as G. caliciformis by authors are different from
the holotype of de Lapparent (1918) and the hypotype of Vogler (1941), and should
be renamed and redescribed in more detail. Similarly, G. contusa (Cushman) of
Troelsen (1955) is different from the holotype of Cushman (1926), and should also be
renamed and redescribed ; the form figured by Berggren (1062) as G. contusa is
doubtfully related to Troelsen’s form, and is completely different from the holotype
of Cushman.

Globotruncana contusa contusa (Cushman) is believed to have evolved from G.
fornicata fornicata Plummer through G. contusa witwickae subsp. nov. as suggested
by the morphological characters and stratigraphical ranges of these forms. However
Gandolfi (1955) suggested the evolution of G. contusa contusa (Cushman) from
G. contusa patelliformis Gandolfi although he admitted its relationship to G. fornicata
fornicata Plummer.

HypotyPes. P.45521.

HORIZON AND LOCALITY. Figured specimens, from sample No. 18, W. El-
Sharawna section.

STRATIGRAPHICAL RANGE. Globotruncana contusa contusa (Cushman) was describ-
ed from the Maestrichtian Mendez shale of Mexico, and was later recorded from the
same formation by Cushman (1927, 1946), White (1928), and Hay (1960). It was
also recorded from the Maestrichtian of the U.S.S.R. (Morozova 1939, Keller 1946,
Subbotina 1953) ; the Campanian—Maestrichtian of Austria and Switzerland
(Noth 1951) ; the Maestrichtian of Trinidad (Bolli 1951, 1957a) ; the Maestrichtian
of Qabeliat and the Campanian—Maestrichtian of the Sudr sections, Sinai, Egypt
(Nakkady & Osman 1954) ; the Maestrichtian Colon shale of northeastern Colombia

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 93

(Gandolfi 1955) ; the Lower and Upper Maestrichtian of the Gamsa Basin, Austria
(Wicher 1956) ; the Lower—Upper Maestrichtian boundary, Cr,-Mb, at Leon,
Belgium (Hofker 1956a) ; the Lower and Upper Maestrichtian of the Atlantic
Coastal Plain (Olsson 1960) ; the Maestrichtian of the Prahova Basin, Romania
(Vinogradov 1960) ; and from the type Maestrichtian of Holland (Hofker 19602,
19624).

In the Esna—Idfu region, G. contusa contusa appears in the basal part of the
G. gansseri Zone. It gradually increases in numbers upwards in the section, to
flood this zone, and then fades out gradually, dying out completely in the overlying
G. esnehensis Zone. No typical representatives of this subspecies were recorded in
the Lower Maestrichtian G. fornicata Zone, which is flooded with transitional stages
between the G. fornicata and G. contusa groups (e.g. G. contusa witwickae) ; while only
rare forms were recorded throughout the G. esnehensis Zone.

All reliable references show that G. contusa contusa ranges throughout the Middle
and Upper Maestrichtian. All records of this subspecies from rocks older than the
Middle Maestrichtian are probably confused with one of the other subspecies or are
erroneous.

Globotruncana contusa patelliformis Gandolfi

(Pl. 8, figs. Ia—c)

1955 Globotruncana (Globotruncana) contusa patellifoymis Gandolfi : 54-55, pl. 4, figs. 2a—c.
1961 Globotyvuncana contusa cf. patellifoymis Gandolfi ; Corminboeuf : 112, pl. 1, figs. ra—c.

DEscripTION. Test large, robust ; trochospiraly coiled in the form a of high,
truncated cone with a subcircular, wide base ; dorsal side very highly raised, and
distinctly coned ; ventral side flat or even slightly concave as the sides gently slope
towards the umbilicus ; equatorial periphery almost circular, slightly lobate, with
two well-developed, heavily beaded marginal keels which become much closer on the
penultimate chamber and reduced to a single, limbate, non-beaded keel on the last
one ; the two keels enclose an almost horizontal and relatively wide peripheral
band which is gradually reduced towards the last chamber ; axial periphery sub-
angular, truncate ; chambers on the dorsal side are not all clear, probably 14 in
number, arranged in 3 dextrally coiled whorls ; initial chambers small, indistinct,
roughly globular, weakly inflated, increasing slowly in size and followed by crescentic,
inflated chambers which are strongly elongated in the direction of coiling and
increasing very rapidly in size ; the last whorl is composed of 4 very long, narrow,
slightly undulating, crescentic chambers which are distinctly elongated in the
direction of coiling and increasing slowly in size ; on the ventral side the chambers
are 4, very long, narrow, distinctly elongated and strongly overlapping ; the very
long sutures on the dorsal side are distinctly curved, strongly raised and heavily
beaded especially in the early part ; on the ventral side the sutures are short, strongly
curved forward, raised and beaded ; umbilicus roughly rectangular in outline, wide,
deep, surrounded by raised, beaded ridges and covered by complex tegilla of which
remnants are still preserved ; primary apertures interiomarginal umbilical ; tegilla,

4 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

with accessory apertures, only poorly preserved ; wall calcareous, perforate,
except for the imperforate keels, peripheral band and tegilla ; surface generally
smooth but with a few scattered papillae on the dorsal side especially in the early part.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter = 6:52 mum.
Minimum diameter = 0-49 mm.
Thickness == OHO Min.

MAIN VARIATION.

1. Chambers 14-21, arranged in 3—4 whorls, which are generally dextrally coiled
(all the specimens studied coiled dextrally).

2. Chambers in the last whorl 4-5, most commonly 4, slightly to moderately
undulate and slowly to moderately increasing in size ; the last chamber is
sometimes slightly smaller than the penultimate.

REMARKS. Globotruncana contusa patelliformis is distinguished from G. contusa
contusa by its more regular, far less plicated, subconical test ; its narrow elongate,
fornicata-type chambers on the ventral side ; strongly curved forward, raised and
beaded ventral sutures and distinctly elongate early chambers. It is also distinguish-
ed from the other members of the G. contusa group by the shape of its ventral cham-
bers and sutures and its robust, regular test.

Globotruncana contusa patelliformis is believed to have evolved from G. fornicata
fornicata Plummer through G. adamsi sp. nov., as suggested by their morphological
characters and stratigraphical distribution. The early part of G. contusa patelli-
formis closely resembles G. adamsi, and the ventral side of the two forms is also very
similar. However, Gandolfi (1955) suggested the evolution of G. contusa patelli-
formis from G. contusa scutilla which can be considered a very small G. contusa
patellifornus, but no transitional stages between these two subspecies were recorded
in the present study. Gandolfi also suggested that G. contusa patelliformis had
evolved into G. contusa contusa (Cushman) by the development of the sharply cut
polygonal periphery, plicated dorsal side, and depressed ventral sutures.

Specimens of G. contusa patelliformis Gandolfi, from the Esna—Idfu region, con-
form well with the original description and figures of the holotype, and with topo-
types kindly forwarded to the present author by Dr. R. Gandolfi.

HypotyPe. P.45522.

HoRIZON AND LOCALITY. Figured specimen from sample No. 18, W. El-Sharawna
section.

STRATIGRAPHICAL RANGE. Gandolfi (1955) described G. contusa patelliformis
from the Colon shale of northeastern Colombia, and gave its range as Campanian—
Maestrichtian. However, analysis of the planktonic Foraminifera of the Colon
shale, described by Gandolfi, suggests a Maestrichtian age for the whole formation.

Corminboeuf (1961) recorded the present subspecies from the Maestrichtian of
Switzerland.

ie

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 95

In the Esna—Idfu region, G. contusa patelliformis occurs in the basal part of the
Middle Maestrichtian G. gansseri Zone, where it increases gradually upwards in the
section to flood the middle and upper parts of this zone and then fades out gradually
in the overlying G. esnehensis Zone before dying out completely in the upper part of
the latter zone.

Globotruncana contusa scutilla Gandolfi
1955 Globotruncana (Globotruncana) contusa (Cushman) scutilla Gandolfi : 54, pl. 4, figs. La—c.

REMARKS. A few specimens referable to the present subspecies were recorded
from the G. fornicata Zone. Morphologically they appear to be so closely similar
to G. contusa patelliformis that they could be considered small forms of it, despite the
great difference in size. However, as it was only recorded from the G. fornicata
Zone of the sections studied, and was stated by Gandolfi (1955) to appear in north-
eastern Colombia much earlier in the succession than G. contusa patelliformis (the
former appears in the Coniacian while the latter appears in what he considered
Campanian), it was found advisable to treat it separately.

G. contusa scutilla (if treated separately from G. contusa patelliformis) is believed
to have evolved from G. fornicata fornicata (Plummer) into G. contusa patelliformis
Gandolfi.

HypotypPe. P.45523.

STRATIGRAPHICAL RANGE. Gandolfi (1955) recorded the present subspecies as
ranging throughout the upper part of the Manaure shale and the basal part of the
Colon shale of northeastern Colombia, which he considered as Coniacian—Lower
Campanian. However, as previously mentioned, all the Colon shale is probably
Maestrichtian in age.

In the Esna—Idfu region G. contusa scutilla occurs as common to rare in the
Lower Maestrichtian G. fornicata Zone only.

Globotruncana contusa witwickae subsp. nov.
(Pl. 7, figs. 1a—c)

Diacnosis. A Globotruncana contusa (Cushman) with much lower spire, less
plicated surface and less elongated chambers on dorsal side.

DESCRIPTION. Test large, robust, spiroconvex, coiled in a relatively high trocho-
spire ; dorsal side moderately convex, gently plicate and undulate ; ventral side
almost flat and weakly inflated ; equatorial periphery bluntly polygonal, with two
well-developed, heavily beaded, marginal keels which enclose a narrow, slightly
inclined peripheral band and tend to weaken towards the last chamber where the
ventral keel is completely reduced ; axial periphery subangular, subtruncate ;
chambers on the dorsal side 17, arranged in 3 dextrally coiled whorls ; initial chambers
very small, globular, weakly inflated, increasing very slowly in size, followed by much

96 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

larger, subglobular, inflated chambers which tend to be roughly crescentic towards
the last whorl and which increase moderately in size ; the last whorl composed of 5
large, narrow, distinctly elongated chambers, roughly crescentic in the early part,
irregular, folded and undulate in the last two chambers, which increase moderately
in size although the last chamber is slightly smaller than the penultimate ; the 5
chambers on the ventral side are large, angular, roughly rectangular, strongly
elongated and increase moderately in size except for the last one ; sutures on the
dorsal side short, curved, beaded in the early part and distinctly elongated, curved,
undulated, raised, thickened and beaded later ; on the ventral side the sutures are
slightly curved in the early part, straight, radial and depressed in the later ; umbili-
cus roughly stellate in outline, relatively wide, deep, bordered by thick beaded
ridges which fade out gradually towards the last chamber ; it is covered by complex
tegilla of which remnants are still preserved ; primary apertures interiomarginal,
umbilical ; tegilla, with accessory apertures, only poorly preserved ; wall calcareous,
perforate except for the imperforate keels, peripheral band and tegilla ; surface
delicately papillose, especially in the early part and on the ventral side.

DIMENSIONS OF HOLOTYPE.

Maximum diameter —— Os 7, tii:
Minimum diameter =" 0°54 mim.
Thickness — Gest anita

REMARKS. This form represents the maximum development of a whole series of
transitional stages between G. fornicata fornicata Plummer and G. contusa contusa
(Cushman). It could neither be included in the former species, although it occurs
with it, nor in the latter as it is morphologically slightly different and stratigraphical-
ly older. It is more closely related to G. contusa contusa (Cushman) of which it is
therefore considered a subspecies.

Pozaryski & Witwicka (1956) mentioned the occurrence of what they described as
G. fornicata var. contusa in the Upper Campanian of the Lublin Basin, central
Poland, but gave no figure or description. Their form may belong to the present
subspecies or it may be transitional to G. fornicata fornicata Plummer. However, as
all forms of G. fornicata which show transitional characters to G. contusa are included
in the present subspecies, Pozaryski & Witwicka’s form is considered to belong here.
This subspecies is named after Dr. E. Witwicka of the Geological Institute, Rako-
wiecka, Poland.

HOLoTyPE. P.45524.
PARATYPES. P.45525.

HORIZON AND LOCALITY. Holotype and paratypes, from sample No. 4, Abou
Saboun section.

STRATIGRAPHICAL RANGE. The subspecies is restricted in the present sections to
the Lower Maestrichtian G. fornicata Zone, where it is common to abundant. The
form described by Pozariski & Witwicka (1956) as G. fornicata var. contusa which

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 97

probably belongs to the present subspecies, was recorded from the Upper Campanian
of central Poland. Records of G. contusa contusa (Cushman) from rocks older than
the Middle Maestrichtian may be of G. contusa witwickae.

Globotruncana cf. convexa Sandidge
(Pl. 1, figs. 5a—c)
1932 Globotvuncana convexa Sandidge : 285, pl. 44, figs. 9-11.

DESCRIPTION. Test small, biconvex, coiled in a low trochosphire ; dorsal side,
moderately arched, ventral side weakly inflated and slightly protruding ; equatorial
periphery roughly ovoid or rather quadrate, distinctly lobate, with two well-develop-
ed, heavily beaded keels enclosing a wide, inclined peripheral band ; axial periphery
truncate ; chambers on dorsal side 15, arranged in 3 dextrally coiled whorls ; the
initial chambers are very small, globigerine, inflated and increase slowly in size ;
the last whorl is composed of 4 large, crescentic chambers which are distinctly
flattened, elongated in the direction of coiling and increase moderately in size ; on the
ventral side the chambers are 4, large, ovoid, weakly inflated and slightly overlapping ;
sutures on the dorsal side curved, raised and heavily beaded ; on the ventral side the
sutures are strongly curved forward, slightly raised and beaded ; umbilicus roughly
quadrangular in outline, wide, deep, bordered by raised, beaded ridges and covered
by complex tegilla of which remnants are still preserved ; primary apertures interio-
marginal, umbilical ; tegilla with accessory apertures only poorly preserved ;
wall calcareous, perforate except for the imperforate keels, peripheral band and

tegilla ; surface delicately papillose in the early part, becoming smoother towards
the last chamber.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter == 0°4010m,
Minimum diameter ==. 0:30 mim.
Thickness —— O07 tim.

REMARKS. Cushman & Hedberg (1941) followed by Cushman & Deaderick (1944),
Cushman (1946), Cita (1948), Hagn (1953) and Graham & Clark (1961) considered
G. convexa Sandidge to be a junior synonym of G. fornicata Plummer. However, as
can be seen from the original description and figures of Sandidge (1932) and from the
samples here studied, G. convexa is more closely related to G. avca (Cushman) than
to G. fornicata Plummer and should be considered separately.

The specimens here described as G. cf. convexa Sandidge differ from the holotype
in being less convex on the dorsal side and in having slightly raised ventral sutures.
Sandidge described the ventral keel on the holotype as poorly developed, while on
the specimen here figured the two keels are both well-developed, although the
tendency towards a less developed ventral keel was clearly observed.

Globotruncana convexa is believed to have evolved from G. ayca (Cushman) by a
reduction in size of test and in the number of chambers, and by the development of
surface rugosity.

HypotyPe. P.455206.

98 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

HORIZON AND LOCALITy. Figured specimen, from sample No. 20, W. El-
Sharawna section.

STRATIGRAPHICAL RANGE. Globotruncana convexa was first recorded by Sandidge
(1932) from the Maestrichtian Ripley formation of Alabama.

In the Esna—Idfu region G. cf. convexa ranges throughout the Maestrichtain,
being common to abundant in the G. fornicata and the G. gansseri Zones, gradually
fades out towards the top part of the latter zone and completely dies out in the
overlying G. esnehensis Zone.

Globotruncana esnehensis Nakkady & Osman
(Pl. 12, figs. ta—d)

1950 Globotyvuncana avca (Cushman) var. esnehensis Nakkady : 690, pl. 90, figs. 23-26.
1954 Globotruncana esnehensis Nakkady & Osman: 79, pl. 19, figs. 3a—-c.

1956b Marginotruncana stuarti (de Lapparent) ; Hofker : 332-333, text-fig. 23.

1956 Globotruncana caliciformis Vogler ; Said & Kenawy : 150, pl. 5, figs. 18a—c.

1956 Globotyuncana intermedia Bolli ; Said & Kenawy : 151, pl. 5, figs. 15a—c.

1961 Globotruncana esnehensis Nakkady, Said & Kerdany : 331, pl. 2, figs. 12a~-c.

wu

EMENDED DIAGNOsIS. A Globotruncana with large, spiroconvex test ; broadly-
domed dorsal side and flat to slightly convex or even slightly concave, undulating
ventral one ; well-developed beaded, single keel ; chambers increasing slowly in size,
almost petaloid on dorsal side and subglobular to ovoid on ventral side ; slightly
curved, raised, beaded dorsal sutures and radial depressed ventral ones ; large
umbilicus and distinctly beaded umbilical ridge ; slightly to moderately lobulate
equatorial periphery and angular, acute axial one; peculiar apertural face of last
chamber and delicately papillose surface.

DeEscripTION. Test large, almost circular in outline, spiroconvex, coiled in a
relatively high trochospire ; dorsal side broadly domed ; ventral side almost flat or
even slightly concave, although the chambers are weakly inflated ; equatorial
periphery circular, moderately lobate with a single well-developed, beaded keel ;
axial periphery angular, acute ; chambers on the dorsal side 19, arranged in three
whorls which are coiled dextrally and very tightly ; they increase slowly and
regularly in size, except the last, which is slightly smaller than the penultimate ;
initial chambers small, inflated, globigerine, followed by relatively large, subglobular,
moderately inflated ones ; the last whorl is composed of 6 large, typically petaloid
chambers which moderately overlap and increase slowly in size ; on the ventral side
the chambers are 6, large, roughly ovoid, slightly inflated and increase so slowly in
size that they all appear to be roughly equal ; each chamber is weakly inflated at its
centre and slopes gently towards the suture on each side giving the ventral surface a
gently undulating appearance ; sutures on the dorsal side are very slightly curved or
almost straight in the early part, very gently curved in the later part, raised and
distinctly beaded ; on the ventral side they are radial, depressed and delicately
beaded ; umbilicus hexagonal in outline, wide, relatively deep, surrounded by a
beaded umbilical ridge and covered by complex tegilla of which remnants are still

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 99

preserved ; primary apertures interiomarginal, umbilical ; tegilla with accessory
apertures only poorly preserved ; wall calcareous, perforate except for the imperfo-
rate keel and tegilla ; surface delicately papillose especially on the early part and on
the ventral side.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter = 0'50 mm.
Minimum diameter == Os44 Tiina:
Thickness == O-27 iui.

MAIN VARIATION.

1. Chambers 15~21, arranged in 3-4 whorls usually dextrally coiled, but sinistral
forms also occur (out of 500 specimens selected at random, 28 coiled sinis-
trally).

2. The last whorl is composed of 5-7 chambers, normally 6, varying in shape from
typically petaloid to slightly elongate or even roughly rectangular, and in
the degree of inflation on the ventral side which may give it a weakly or
distinctly undulating appearance.

REMARKS. Globotruncana ensehensis was first described by Nakkady (1950) as
a variety of Globotruncana arca (Cushman). Nakkady & Osman (1954) realizing the
great difference between this form and G. arca (Cushman), quite justifiably raised it
to specific rank. Hofker (1956c: 75) and Berggren (1962 : 31) considered G. esnehen-
sis as a junior synonym of Abathomphalus intermedia (Bolli), but the two species are
too remote to be related to each other. Again, Said & Kenawy (1956) described as
G. intermedia Bolli, and G. calicifornis Vogler, forms which are actually G. esnehensis.

The evolutionary history of G. esnehensis is not clearly known because its strati-
graphical range has been somewhat confused. However, its morphological similarity
to both G. orientalis sp. nov. and G. fareedi sp. nov., which appear earlier in the
section, may suggest its evolution from one of these species, although no direct
evidence was recorded. Again, it is possible that G. esnehensis has evolved from
G. conica White, although the morphological characters and stratigraphical range of
the latter species have been very much confused.

Specimens of G. esnehensis, from the Esna—Idfu region, conform well with the
holotype of G. arca (Cushman) var. esnehensis of Nakkady (1950) (B.M.N.H.,
P.41780), the paratypes (P.41781), and with the description and figures of Nakkady
& Osman (1954).

Hypotype. P.45527.

HORIZON AND LOCALITY. Figured specimen, from sample No. 17, W. EI-
Sharawna section.

STRATIGRAPHICAL RANGE. Nakkady (1950) described G. avca (Cushman) var.
esnehensis from the Maestrichtian Esna shale of the Abu Durba section, western
Sinai, Egypt. He also reported it to be frequent in the Maestrichtian Globotruncana—
Guembelina Zone of the Abu Durba and Mellaha sections and to flood the Maestrich-
tian chalk of Gebel Duwi.

100 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

Nakkady & Osman (1954) described G. esnehensis from the Campanian—Maestrich-
tian of southern and western Sinai, Egypt and it was recorded from the Maestrichtian
of northern Sinai (Said & Kenawy 1956), the Maestrichtian of the Farafra Oasis
(Said & Kerdany 1961) and from the Lower Maestrichtian of northwestern Germany
and Holland (Hofker 1956)).

In the Esna—Idfu region G. esnehensis appears in the basal part of the Middle
Maestrichtian Globotruncana gansseri Zone as a common form, increases gradually
upwards in the section, flooding the upper part of the Maestrichtian and character-
izing the Globotruncana esnehensis Zone, the upper part of which is truncated by the
disconformity separating it from the overlying basal Tertiary rocks.

Globotruncana fareedi sp. nov.
(Pl. 9, figs. 4a—d)

? 1946 Globotrvuncana rosetta (Carsey) ; Keller : 102, pl. 2, figs. 17-19, pl. 3, fig. 6.
21955 Globotruncana rosetta insignis Gandolfi : 67, pl. 6, figs. 2a—c.
1956 Globotrvuncana falsostuarti Sigal ; Knipscheer : 54, pl. 4, figs. 13a, b, 16a—c, text-fig. 4.

Driacnosis. A Globotruncana with large, circular, biconvex test ; distinctly
lobate periphery ; characteristic, roughly quadrangular chamber shape on both
sides ; entirely single keel ; short, nearly radial, depressed, sutures on ventral side ;
raised, thickened, beaded, imbricate umbilical ridges, and wide, peculiarly-shaped
umbilicus.

DEscRIPTION. Test large, circular, biconvex ; dorsal side arched ; ventral side
moderately protruding ; periphery circular, distinctly lobate, transversally acute,
with a single well-developed, beaded keel ; chambers on the dorsal side 18, arranged
in 3 dextrally coiled whorls ; initial chambers small, inflated, globigerine, followed by
roughly quadrangular chambers which increase regularly in size ; the last whorl is
composed of 6 large, quadrangular chambers which are very slightly elongated in the
direction of coiling ; on the ventral side the 6 large, roughly quadrangular chambers
are moderately inflated especially around the umbilicus, and taper out gradually
towards the periphery ; sutures on the dorsal side slightly curved in the early part,
nearly straight in the last part, raised and beaded ; on the ventral side the sutures
are very slightly curved or nearly straight, radial and strongly depressed especially
towards the periphery, while towards the umbilicus they are slightly raised, thickened
and beaded before curving around the umbilicus and joining to form a much thick-
ened, raised, beaded umbilical flange ; umbilicus wide, deep, roughly hexagonal,
covered by complex tegilla of which remnants are still preserved ; primary apertures
interiomarginal, umbilical ; tegilla with accessory apertures only poorly preserved ;
wall calcareous, perforate, except for the imperforate keel and tegilla ; surface
smooth and finely porous.

DIMENSIONS OF HOLOTYPE.
Maximum diameter == Tigao min,
Minimum diameter ==") Or4gvmiim,
Maximum thickness == O-22 Titi

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT IOI

MAIN VARIATION.

1. The test may be strongly or weakly biconvex.

2. Chambers 18-24 arranged in 3-4 whorls, (all the specimens studied coiled
dextrally).

3. The beading of the sutures and the keel may be heavy throughout or may fade
out gradually towards the last chamber.

4. The rate of growth may be slow and constant, leading to a regular increase in
chamber size, or it may be rapid in the later stage, producing relatively
bigger chambers in the last whorl.

5. The dorsal surface of each of the chambers in the last whorl (not the dorsal
side of the test) is flat, slightly convex, or even slightly concave.

6. The umbilicus is moderate to large and the ventral sutures are either slightly
or strongly depressed.

REMARKS. Globotruncana fareedi sp. nov. morphologically resembles both
G. stuarti stuart (de Lapparent) and G. esnehensis Nakkady & Osman. It is dis-
tinguished from the former by its equally biconvex test, lobate periphery, quad-
rangular rather than trapezoidal chambers on the dorsal side ; short, depressed
radial sutures on the ventral side and less tangential ones on the dorsal ; its much
wider umbilicus and imbricate umbilical flange. It differs from G. esnehensis in
having a biconvex test, a much lower dorsal side and a more protruding ventral one,
quadrangular chambers on the ventral side and less inflated ones on the dorsal,
much wider umbilicus and an imbricate umbilical flange. Globotruncana falsostuarti
Sigal has a similarly wide umbilicus and discontinuous umbilical flange, but is
distinguished by its double keel and more protruding ventral side.

Globotruncana fareedi sp. nov. was probably confused in the past with both
G. rosetta rosetta (Carsey) and G. falsostuarti Sigal. However, G. rosetta rosetta is
distinguished by its perfectly plano-convex, umbilico-convex test ; double keel on
the early chambers of the last whorl, becoming single on the last chambers; its flat
crescentic chambers on the dorsal side, and angular conical, strongly protruding ones
on the ventral ; its narrower umbilicus, and slightly rougher surface. The forms
described as G. rosetta (Carsey) by Keller (1946) and as G. rosetta insignis by Gandolfi
(1955) are not related to G. rosetta, but probably belong to the present species,
although Gandolfi’s form shows a flatter dorsal side and a slightly narrower umbilicus.
Again, G. falsostwarti Sigal was so briefly described that its diagnostic features were
not really known, and thus it has often been misinterpreted. The forms figured by
Knipscheer (1956) as G. falsostuarti are different from Sigal’s holotype, but may well
belong to the present species, while the form described as G. rosetta pembergeri by
Papp & Kipper (1953) most probably belongs to G. falsostuarti Sigal. Through the
kindness of Dr. J. Sigal, the type specimens of G. falsostuarti, which are in his
personal collection, were examined by the present author. This examination
showed that :

1. The holotype of G. falsostuartz is distinguished by its unequally biconvex test ;

strongly protruding ventral side ; two closely spaced keels, the ventral one
of which is slightly shifted towards the inner side of the test and is reduced

102 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

on the last chamber ; its highly beaded keels and dorsal sutures ; inclined
peripheral band ; raised, beaded, discontinuous umbilical flange ; and
inclined, raised, beaded ventral sutures. It is more closely related to
G. arca (Cushman) than to G. stwarti stuarti (de Lapparent).

2. The paratypes of G. falsostuarti include forms belonging to G. stuart: stuarti
(de Lapparent), G. conica White, G. esnehensis Nakkady & Osman and
G. fareedi sp. nov.

The similarity in the shape of the chambers and the sutures on both sides, the
distinctly lobate, circular periphery and the entirely single keel, suggest that G.
fareedi sp. nov. has possibly evolved from G. elevata (Brotzen) in early Maestrichtian
time, although its evolution from G. stwarti stuarti (de Lapparent) is not excluded.
Again, G. fareedi may have evolved into G. esnehensis Nakkady & Osman in early
Middle Maestrichtian time by increasing the convexity of the dorsal side and flatten-
ing the ventral side. The diagnostic features and stratigraphical ranges of these
species favour these propositions.

This species is named after Dr. Fareed El-Naggar of the National Institute of
Management Development, Cairo.

HoLotyre. P.45528.
PARATYPES. P.45666.

HORIZON AND LocALity. MHolo- and paratypes, from Sample No. 24, W. El-
Sharawna section.

STRATIGRAPHICAL RANGE. G. fareedi occurs as rare to common in the L. Maestri-
chtian G. fornicata Zone, common to abundant in the Middle Maestrichtian G.
ganssert Zone, and dies out in the basal part of the Upper Maestrichtian G. esnehensis
Zone.

Globotruncana fornicata ackermanni Gandolfi
(Pl. 14, figs. 3a—5d)

1955 Globotruncana fornicata ackermanni Gandolfi : 42-43, pl. 2, figs. 5a—7c.
? 1958 Globotruncana fornicata ackermanni Gandolfi ; Ansary & Fakhr : 135, pl. 2, figs. 16a—c.

DESCRIPTION. (Specimen, Pl. 14, figs. 4a—-d.) Test small, biconvex, coiled in a
low trochospire ; dorsal side slightly convex, moderately inflated, ventral side
inflated, moderately protruding ; equatorial periphery roughly ovoid or rather
quadrate, moderately lobate, with two well-developed, delicately beaded, slightly
diverging, imbricate keels, enclosing a wide, slightly depressed peripheral band ;
axial periphery globular, subtruncate ; chambers on the dorsal side 15, arranged in 3
dextrally coiled whorls ; the initial ones are small, globular, inflated, increase
slowly in size and are followed by relatively larger, globular, more inflated chambers
which increase moderately in size ; the last whorl is composed of 4 large chambers
which are subglobular in the early part, crescentic and strongly elongated in the
direction of coiling in the later part and which increase rapidly in size ; the last
chamber is very well-developed and constitutes about 4 of the test ; on the ventral

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 103

side the chambers are 4, large, subglobular in the early part, ovoid in the last chamber,
strongly inflated and increase rapidly in size ; sutures on the dorsal side curved,
raised, delicately beaded and merge into relatively shallow depressions from the
periphery inwards towards the spiral suture ; on the ventral side the sutures are
radial and depressed ; umbilicus irregular in outline, wide, deep and covered by
complex tegilla of which remnants are still preserved ; primary apertures interio-
marginal, umbilical ; tegilla, with accessory apertures, only poorly preserved ;
wall calcareous, perforate except for the imperforate keels, peripheral band and
tegilla ; surface rough, coarsely papillose.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter == 0°36 mim,
Minimum diameter = 0:29 mm.
Thickness — 0-22. 1iita

VARIATION. The main variation observed in G. fornicata ackermanni is in the
degree of inflation of both sides, imbricate arrangement of keels, rate of growth and
surface rugosity.

REMARKS. Globotruncaca fornicata ackermanni is believed to have evolved from
G. fornicata fornicata Plummer by reduction in the size of test, greater inflation of
the chambers, imbricate arrangement of keels and peripheral band and the develop-
ment of surface rugosity. The form here figured (Pl. 14, figs. 3a-d) shows inter-
mediate characters between the two subspecies and is thus considered as a transition-
al stage.

HypotypPes. P.45529.

HORIZON AND LOCALITY. Figured specimes, from sample No. 4, Abou Saboun
section.

STRATIGRAPHICAL RANGE: Gandolfi (1955) described G. fornicata ackermannt
from the Colon shale of northeastern Colombia, where he considered its range as
Campanian—Lower Maestrichtian. It was also recorded from the Maestrichtian of
Um E]-Huetat section west of Safaga, Eastern Desert, Egypt (Ansary & Fakhr, 1958).

In the Esna—Idfu region, G. fornicata ackermanni occurs as a common to abundant
form in the Lower Maestrichtian G. fornicata Zone and dies out completely towards
the top part of this zone.

Globotruncana fornicata cesarensis Gandolfi
(Pl. 13, figs. 3a-4c ; Pl. 14, figs. 6a—c)
1955 Globotruncana fornicata cesarensis Gandolfi : 45, pl. 2, figs. 1oa—c.
DESCRIPTION. (Specimen, Pl. 14, figs. 6a—-c.) Test medium-sized, biconvex,
coiled in a low trochospire ; dorsal side convex, moderately inflated, and slightly

folded in the last chamber, ventral side slightly inflated ; equatorial periphery
roughly ovoid, moderately lobate, with two well-developed, delicately beaded

104 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

marginal keels enclosing a wide peripheral band which widens out towards the last
chamber ; axial periphery truncate ; chambers on the dorsal side are not all clear but
appear to be I5 in number, arranged in 3 dextrally coiled whorls ; initial chambers
extremely small, globular, weakly inflated and increase slowly in size ; they are
followed by slightly larger, globular inflated chambers which increase slowly in size
up to the beginning of the last whorl where they start to enlarge very rapidly ; the
last whorl is composed of 4 large, strongly inflated chambers which are roughly
globular in the early part, crescentic and strongly elongated in the direction of coiling
in the later part and increasing so rapidly in size that the last chamber constitutes
about half the test ; on the ventral side the chambers are 4, subglobular in the early
part, strongly elongated in the last chamber which constitutes about half of the test ;
sutures on the dorsal side curved, raised, beaded, merging into relatively sharp
depressions before joining the spiral suture ; on the ventral side the sutures are
radial and depressed ; umbilicus irregular in outline, relatively wide, deep, bordered
by weakly raised, delicately beaded umbilical ridges, and covered by complex tegilla
of which remnants are still preserved ; primary apertures interiomarginal umbilical ;
tegilla, with accessory apertures, only poorly preserved ; wall calcareous, perforate
except for the imperforate keels, peripheral band and tegilla ; surface rough,

delicately papillose, with the roughness decreasing gradually towards the last
chamber.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter == ©°43'mm.
Minimum diameter = 0°31 mm.
Thickness = 0°25 mm.

VARIATION. The main variation observed in this subspecies is in the degree of
inflation of the chambers in the last whorl, the degree of surface plication on the
dorsal side and in the surface roughness.

REMARKS. Globotruncana fornicata cesarensis was first described by Gandolfi
(1955) and considered to represent a final stage in the evolution of the G. fornicata
group, characterized by the reduction in the size of test and in the number of chamb-
ers in the last whorl. The present study substantiates Gandolfi’s conclusion, although
his G. fornicata plummerae which he regarded as the ancestor of G. fornicata cesar-
ensis, is here considered a junior synonym of G. fornicata fornicata Plummer.

Specimens of G. fornicata cesarensis, from the Esna—Idfu region, conform well with
Gandolfi’s original description and figures. However, two distinct morphological
types of this subspecies were recorded, one with a smooth test and a non-inflated
dorsal side (e.g. Pl. 13, figs. 3a—c), the other with a moderately to distinctly inflated
dorsal side and a rougher surface. The former type was clearly observed high in the
section while the latter was found to flood the lower part. It is possible that further
study may prove these types to be worthy of distinction. However, as such varia-
tion was mentioned by Gandolfi (1955), and as the former type was found to be rather
rare in the samples studied, the two forms are here assigned to the same subspecies.

HypotyPes. P.45530.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 105

HorRIZON AND LOCALITY. Figured specimens, Pl. 13, figs 3a-c from sample No.
16, W. El-Sharawna section, figs. 4a—c, from sample No. 14, Gebel A 314 section ;
Pl. 14, figs. 6a—c, from sample No. 4, Abou Saboun section.

STRATIGRAPHICAL RANGE. Gandolfi (1955) described this subspecies from the
Colon shale of northeastern Colombia where he considered its range as Campanian—
basal Maestrichtian.

In the Esna—Idfu region, G. fornicata cesarensis floods the Lower Maestrichtian
G. fornicata Zone, fades out gradually upwards in the section and occurs as a rare
form in the basal part of the overlying G. gansseri Zone where it dies out completely.

Globotruncana fornicata fornicata Plummer
(Pl. 13, figs. 5a—c, 6; Pl. 14, figs. 1a—c)

1931 Globotrvuncana fornicata Plummer : 108, pl. 13, figs. 4a—c, 5, 6.
1951 Globotruncana fornicata Plummer ; Drooger : 7, pl. 1, figs. 9a—c.
1953 Globotruncana fornicata Plummer ; Hagn: 98, pl. 8, figs. 8a—c, text-figs. 22, 23.
1953 Globotruncana fornicata Plummer ; Subbotina : 184-185, pl. 8, figs. 3a—c, ? 4a—5c.
1955 Globotyuncana (Globotruncana) fornicata plummerae Gandolfi : 42, pl. 2, figs. 3a—c, ? 4a—c.
1961 Globotruncana fornicata Plummer ; Graham & Clark: 112, pl. 5, figs. toa—c.
1962 Globotruncana (Globotruncana) fornicata Plummer ; Pessagno : 362, pl. 4, figs. 4, 5, II.
1963 Globotruncana fornicata Plummer ; Lehmann: 148, pl. 7, figs. 1a—2c ; ? 3a—4c ; text-

figs. 2, w ; 3n,7,t

DESCRIPTION. (Specimen, Pl. 13, figs. 5a—c.) Test large, biconvex, coiled in a
low trochospire ; dorsal side slightly convex, moderately inflated, ventral side
slightly more inflated and relatively protruding ; equatorial periphery ovoid,
slightly lobate, with two well-developed, delicately beaded diverging keels ; axial
periphery truncate ; chambers on the dorsal side 17, arranged in 3 dextrally coiled
whorls ; initial chambers very small, almost indistinct, globigerine, weakly inflated,
increasing slowly in size ; they are followed by relatively larger, globular, slightly
inflated chambers which also increase slowly in size till the beginning of the last
whorl where they start to change their shape and rate of growth ; the last whorl
constitutes most of the test and is composed of 4+ large, long, narrow inflated,
slightly folded, highly curved crescentic chambers ; on the ventral side the chambers
are 4, kidney-shaped, moderately inflated and strongly overlapping ; sutures on the
dorsal side are curved, raised, delicately beaded, tending to merge into relatively
sharp depressions from the periphery inwards towards the preceding whorl (as in
Plummer’s description) ; on the ventral side the sutures are strongly curved forward,
slightly raised and delicately beaded ; umbilicus roughly rhomboidal in outline,
wide, deep, bordered by slightly raised delicately beaded ridges, covered by complex
tegilla of which remnants are still preserved ; primary apertures interiomarginal,
umbilical ; tegilla, with accessory apertures, only poorly preserved ; wall calcareous,
perforate except for the imperforate keels, peripheral band and tegilla ; surface
delicately papillose in the early part and on the ventral side, becoming smooth
towards the last chamber ; the two keels enclose a relatively wide, depressed,
slightly inclined peripheral band which is relatively narrow at the posterior part of
test but widens out anteriorly as the keels diverge.

106 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter = 0'5 hmm:
Minimum diameter = 0"39' nam.
Thickness = /0°245m0m.

MAIN VARIATION.

1. Test medium-sized to large, subcircular to ovoid in outline.

2. Dorsal side very slightly raised to moderately convex, gently plicate to
slightly folded.

3. Ventral side inflated, slightly to moderately protruding.

4. Chambers 14-18, arranged in 2}-3 whorls, usually dextrally coiled (of 60
specimens picked at random, 4 coiled sinistrally).

5. Usually 4 or 5 chambers in the last whorl : specimens with 33 or 6 chambers
occur very rarely.

6. The peripheral band varies in width and in degree of inclination towards the
ventral side.

7. The two keels can either be occasionally developed or the ventral keel may
equally weaken towards the last chamber.

8. The surface is generally smooth but is sometimes delicately papillose in the
early part.

REMARKS. As was mentioned in part by Gandolfi (1955) Globotruncana fornicata
Plummer (1931) and of authors, is actually a group of closely related forms. These
are generally characterized by a biconvex, double-keeled test, small, globigerine,
early chambers, and long, narrow highly arched later ones ; these are slightly to
moderately plicate on the dorsal side and moderately to strongly overlapping on the
ventral. They are also characterized by a slightly inclined peripheral band and
dorsal sutures which merge into relatively sharp depressions from the periphery
inwards.

Gandolfi considered some of these related forms to be subspecies of G. fornicata,
and described the following :

Globotruncana fornicata fornicata Plummer 1931.

Globotruncana fornicata plummerae Gandolfi 1955.

Globotruncana fornicata ackermanni Gandolfi 1955.

Globotruncana fornicata cesarensis Gandolfi 1955.

Globotruncana fornicata manaurensis Gandolfi 1955.

However, Gandolfi’s specimen described as G. fornicata fornicata Plummer
differs from Plummer’s original description and figures and may possibly be a
distinct form. On the other hand, examination of topotypes of G. fornicata plum-
merae, kindly presented by Dr. R. Gandolfi, proved their identity with G. fornicata
fornicata Plummer from the Esna—Idfu region and with topotype material kindly
sent by Dr. E. A. Pessagno, Jr., of the University of California. Thus G. fornicata
plummerae Gandolfi is considered to be a junior synonym of G. fornicata fornicata
Plummer.

The other forms described by Gandolfi are here recognized as valid subspecies.
A new subspecies of G. fornicata was also discovered during the present study and

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 107

named G. fornicata globulocamerata ; it is distinguished by a tendency to have
globular chambers in the last whorl instead of the extremely elongated chambers of
the central type.

The lumping of these subspecies and their transitional forms as G. fornicata
Plummer has confused the diagnostic features and stratigraphical range of G.
fornicata fornicata. However, it is clearly distinguished by its biconvex test,
extremely elongated chambers in the last whorl which are slightly plicate on the
dorsal side and sometimes inflated towards their inner extremities, and strongly
overlapping on the ventral side ; its curved, raised, beaded, ventral sutures and
strongly diverging double keel.

Glaessner (1937 : 43, text-fig. 5) suggested the evolution of G. fornicata Plummer
from Rotalipora appenninica (Renz), in Coniacian—Santonian time through a yet
unknown form. However, Bolli (1951) and Gandolfi (1955, pl. 10) suggested its
evolution from G. lapparenti lapparenti (Brotzen) while Bronnimann & Brown (1956)
suggested that it evolved from G. imbricata Mornod. Moreover, Gandolfi (1955)
suggested the evolution of G. fornicata fornicata Plummer from G. fornicata manaur-
ensis by the gradual reduction of the tight coiling of the chambers, by the reduction
in the number and degree of overlap of chambers, and by the anterior divergence of
the two keels. It is also evident that members of the G. fornicata group have
gradually evolved into the corresponding members of the G. contusa group, through
various transitional stages, as was partly mentioned by Glaessner (1937), Bolli (1951),
Gandolfi (1955), and Brénnimann & Brown (1956), and is clearly documented in the
present study.

G. fornicata formicata is believed to have evolved into G. contusa contusa through
G. contusa witwickae subsp. nov., and into G. contusa sensu Troelsen through G.
fornicata globulocamerata subsp. nov.

Hypotypes. P.45531.

HorRIZON AND LOCALITY. Figured specimens, Pl. 13, figs. 5a—c, from sample No.
14, G. A 314 ; fig. 6, from sample No. 3, Abou Saboun section ; Pl. 14, figs. 1a—c from
sample No. 4 Abou Saboun section.

STRATIGRAPHICAL RANGE. Globotruncana fornicata fornicata Plummer was first
described from the Upper Taylor (Campanian) Formation of Texas (Plummer 1931,
sta. 226—-T-8) and was recorded as very common to abundant in Taylor and Navarro
strata which, according to Bolli (1957, 1959), corresponds to the Upper Santonian—
Lower Maestrichtian of Western Europe. It was recorded from the same horizon
by Cushman & Todd (1943), Cushman (1944, 1946, 1948), and by Frizzell (1954) who
showed that it ranges throughout the whole Taylor and Lower Navarro groups,
being most abundant in the upper Taylor beds, and that it never occurs below the
base of the Taylor formation. Albritton & Phleger (1937) restricted its range to the
Taylor group only, while Bronnimann & Brown (1956) recorded its range as Coniacian
to Campanian, possibly Maestrichtian. Hagn (1953) described it from the Upper
Campanian of Germany, Barr (1962) from the Campanian of the Isle of Wight,

108 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

England, and Lehmann (1963) from the Coniacian—Campanian of the Tarfaya
province, western Morocco.

Other authors, by misidentifying Plummer’s species, or by confusing it with other
subspecies, gave various ranges between Upper Turonian and Lower Maestrichtian,
although it was clearly stated (Frizzell 1954) that in the type locality it was not
found below the Upper Santonian (base of the Taylor formation).

In the Esna—Idfu region Globotruncana fornicata fornicata Plummer floods the
basal part of the Sharawna shale formation, characterizing the G. fornicata Zone, to
which it is restricted and in which it constitutes, together with its subspecies, the
bulk of the planktonic Foraminifera. It fades out gradually upwards in the section
disappearing completely below the overlying G. gansseri Zone.

Globotruncana fornicata globulocamerata subsp. nov.
(Pl. 13, figs. ra—c ; Pl. 14, figs. 2a-c)

Diacnosis. A Globotruncana fornicata with globigerine character of early
chambers extending to most of last whorl, final one or two chambers only are
distinctly elongated in direction of coiling.

DESCRIPTION. (Holotype, Pl. 14, figs. 2a-c.) Test medium sized, biconvex,
coiled in a low trochospire ; dorsal side gently arched and moderately inflated,
ventral side slightly inflated and weakly protruding ; equatorial periphery roughly
ovoid, weakly lobate, with two well-developed, much thickened and delicately
beaded marginal keels enclosing a relatively wide, slightly inclined peripheral band,
which widens out gradually towards the last chamber ; axial periphery distinctly
truncate ; chambers on the dorsal side 17, arranged in 3 dextrally coiled whorls ;
the initial chambers are exceedingly small, almost indistinct, slightly depressed,
globular, weakly inflated, and increase very slowly in size ; they are followed by
relatively larger, globular, inflated chambers which increase moderately in size ; the
last whorl is composed of 5 large, inflated chambers which are subglobular and increase
slowly in size except for the last which is crescentic, strongly elongated in the direc-
tion of coiling, and constitutes about 4 of the test ; on the ventral side the chambers
are 5, large, inflated, subglobular, moderately overlapping and increase slowly is size
except the last one which is ovoid, elongated, strongly inflated and constitutes about
+ of the test ; sutures on the dorsal side slightly curved, raised and delicately
beaded, although the inflation of the chambers on both sides makes them appear to
run in very shallow sutural depressions ; on the ventral side the sutures are curved,
slightly raised and delicately beaded ; umbilicus irregular in outline, relatively wide,
shallow, bordered by slightly raised, delicately beaded ridges and covered by complex
tegilla of which remnants are still preserved ; primary apertures interiomarginal,
umbilical ; tegilla, with accessory apertures, only poorly preserved ; wall calcareous,
perforate except for the imperforate keels, peripheral band and tegilla ; surface
slightly rough, delicately papillose especially on the ventral side with the roughness
decreasing gradually towards the last chamber.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 109

DIMENSIONS OF HOLOTYPE.

Maximum diameter ==) 0843 mmm
Minimum diameter =) 0432 mime
Thickness — 0-22 mim:

VARIATION. The main variation observed in specimens of G. fornicata globulo-
camerata is in the degree of globularity of the last chambers and the degree of surface
roughness.

Remarks. All members of the G. fornicata group are generally characterized
by an early globigerine part, and later crescentic chambers which are strongly
curved and distinctly elongated in the direction of coiling. The present form,
however, represents a distinct type of this group in which the early globigerine
character extends to most of the final whorl, while the last one or two chambers still
keep the characteristic chamber form which is strongly elongated in the direction
of coiling. As all the other characters of the G. fornicata group are retained in the
present form, and as it has a slightly different stratigraphical range from G. fornicata
formcata Plummer, it is here considered as a distinct subspecies. The name
G. formicata globulocamerata describes the globular character of most of its chambers.

G. forncata globulocamerata is believed to have evolved from G. fornicata fornicata
Plummer, and into G. contusa sensu Troelsen, as suggested by the morphology and
stratigraphical distribution of these forms.

HoLotyPe. P.45532.
PARATYPES. P.45533-34.

HORIZON AND LOCALITY. Holotype, Pl. 14, figs. 2a—c, and paratype Pl. 13,
figs. Ia—c, from samples No. 4 and 3 respectively, Abou Saboun.

STRATIGRAPHICAL RANGE. In the Esna—Idfu region, G. fornicata globulocamerata
occurs aS a common to abundant form throughout the Lower Maestrichtian G.
fornicata Zone, fading out gradually upwards in the section and dying out completely
below the overlying G. ganssevi Zone.

Globotruncana fornicata manaurensis Gandolfi
(Pl. 13, figs. 2a—c)
1955 Globotruncana fornicata manaurensis Gandolfi: 41, pl. 2, fig. 1a—c, text-fig. 9 (1a-c ;
2a-C).

DESCRIPTION. Test medium-sized, unequally biconvex, coiled in a low trocho-
spire ; dorsal side convex, moderately arched and slightly inflated, ventral side
almost flat, slightly raised and weakly inflated ; equatorial periphery subcircular,
slightly lobate, with two well-developed, closely spaced, thickened marginal keels ;
axial periphery subangular, subtruncate ; chambers on the dorsal side are not all
clear, but appear to be 18 in number, arranged in 3 dextrally coiled whorls ; the
initial chambers are very small, almost indistinct and are followed by slightly larger,
globular, inflated chambers which become roughly crescentic towards the last whorl
and increase moderately in size ; the last whorl is composed of 6 (5 + I abortive)

110 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

large chambers which are highly arched, distinctly elongated in the direction of
coiling and increase slowly in size ; on the ventral side the chambers are 5, large,
ovoid, and distinctly overlapping while they increase slowly in size ; each chamber is
surrounded by a horseshoe-shaped, delicately beaded raised ridge ; sutures on the
dorsal side strongly curved, distinctly raised, much thickened and limbate ; on the
ventral side the sutures are strongly curved forward, slightly raised and limbate;
umbilicus roughly pentagonal in outline, wide, deep, surrounded by much-thickened
ridges and covered by complex tegilla, of which remnants are still preserved ;
primary apertures interiomarginal, umbilical ; tegilla, with accessory apertures, only
poorly preserved ; wall calcareous, perforate except for the imperforate keels,
peripheral band and tegilla ; surface smooth.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter == | Oar im.
Minimum diameter = 0:35 mm.
Thickness == 0-22 mmr

REMARKS. Gandolfi (1955) considered this subspecies to be the ancestral stock
from which both the G. fornicata and the G. contusa groups have evolved, through
G. fornicata fornicata Plummer in the former, and G. contusa scutilla Gandolfi in the
latter. He also mentioned a somewhat dubious relationship with what he described
as the G. calicifornis—intermedia group and suggested the evolution of the present
subspecies from G. lapparenti lapparenti (Brotzen) [= G. linneiana linneiana
(d’Orbigny)].

The present study substantiates Gandolfi’s suggestion in part, namely that
G. fornicata manaurensis evolved from G. linneiana linneiana (d’Orbigny) and that
it possibly evolved into G. fornicata fornicata Plummer. Transitional stages
between the present subspecies and G. tricarinata tricarinata (Quereau), were also
recorded (e.g. Pl. 14, figs. 7a-c).

Specimens of G. fornicata manaurensts, although rare in the samples studied,
compare well with Gandolfi’s original description and figures, and with topotype
material kindly forwarded to the present author by Dr. R. Gandolfi.

HypotyPes. P.45535-36.

HORIZON AND LOCALITY. Figured specimen from Sample No. 14, G. A 314
section.

STRATIGRAPHICAL RANGE. Globotruncana fornicata manaurensis was described by
Gandolfi (1955) from the Manaure shale of northeastern Colombia where he considered
its range as Coniacian—Santonian. In the Esna—Idfu region it occurs as a very rare
form in the Lower Maestrichtian G. fornicata Zone only.

Globotruncana fundiconulosa Subbotina
1953 Globotyuncana fundiconulosa Subbotina : 200, 201, pl. 14, figs. ta—4c ; pl. 15, figs.
1a—2b.
1955 Globotruncana wiedenmayeri wiedenmayeri Gandolfi : 71, pl. 7, figs. 4a-c.
21955 Globotruncana wiedenmayeri magdalenaensis Gandolfi : 72, pl. 7, figs. 3a-c.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT ITI

Remarks. The forms described by Gandolfi (1955) as G. wiedenmayert wieden-
mayert and G. wiedenmayert magdalenaensis are morphologically similar to the
present species, and have the same stratigraphical range. They are thus considered
to be junior synonyms, as previously mentioned by Berggren (1962).

HypotTyPe. P.45537.

HORIZON AND LOCALITY. Hypotype from sample No. 18, W. El-Sharawna
section.

STRATIGRAPHICAL RANGE. The species was recorded by Subbotina (1953) to range
through the Campanian—Maestrichtian of the U.S.S.R., and by Gandolfi (1955) from
the Campanian—Maestrichtian of northeastern Colombia. In the Esna—Idfu region
G. fundiconulosa occurs as a rare form in the Lower Maestrichtian G. fornicata Zone
and the lower part of the overlying G. gansseri Zone where it dies out completely.

Globotruncana gagnebini Tilev
(Pl. 2, figs. 1a—4d ; Pl. 3, figs. 1a—-d, 3a-d, 6)

1951 Globotruncana gagnebini Tilev : 50-56, pl. 3, figs. 2-5, text-figs. 1ga—e, 15a—17d.

1951 Globotruncana ventricosa White ; Bolli: 190, text-fig. re.

1951a Globotruncana cretacea Cushman ; Nakkady (pars) : 57-58, pl. 2, fig. 2D, E, non A-C.
1952 Globotruncana gagnebini Tilev ; Tilev : 50-56, pl. 3, figs. 2-5, text-figs. 14a—e, 15a—17d.
1955 Globotyuncana ventricosa ventricosa (White); Gandolfi: 22, 23; pl. 1, figs. 5a—c.

1955 Globotyuncana arca caribica Gandolfi : 64, pl. 5, figs. 5a—c.

19574 Globotruncana gagnebini Tilev ; Bolli: 59, pl. 14, figs. 5a—c.

DESCRIPTION. (Specimen, Pl. 2, figs. ta-d.) Test large, planoconvex, umbilico-
convex, coiled in a very low trochospire ; dorsal side almost flat, ventral side distinctly
protruding ; equatorial periphery roughly ovoid, slightly lobate, with two well-
developed, thickened, beaded keels enclosing a narrow peripheral band ; axial
periphery truncate ; chambers on the dorsal side 14, arranged in 3 dextrally coiled
whorls ; the initial ones are small, inflated, globigerine, and increase slowly in size ;
the last whorl is composed of 54, large, crescentic chambers which are elongated in
the direction of coiling and increase very rapidly in size ; on the ventral side the
chambers are 5}, large, raised, distinctly protruding, subglobular in the early part
and elongate later ; sutures on the dorsal side curved, raised and beaded ; on the
ventral side they are radial or very slightly curved forward and depressed ; umbilicus
wide, deep, bordered by raised, thick, limbate ridges and covered by complex tegilla
of which remnants are still preserved ; primary apertures interiomarginal, umbilical ;
tegilla with accessory apertures only poorly preserved ; wall calcareous, perforate
except for the imperforate keels, peripheral band and tegilla ; surface smooth except
for a few scattered papillae on the early part.

DIMENSIONS OF DESCRIBED SPECIMEN.
Maximum diameter = 0-42mm,.
Minimum diameter == 0°35 mm:
Thickness =—s 50222".

Tie UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

MAIN VARIATION.

1. The test is small to large, subcircular to ovoid, moderately to strongly elongate.

2. The dorsal side is either flat, very slightly raised or even slightly depressed,
while the ventral side is always protruding, sometimes strongly so that the
protruding ventral mass lies almost at right angles to the marginal periphery.

3. Equatorial periphery subcircular to ovoid, slightly to moderately lobate ;
axial periphery moderately to distinctly truncate.

4. The two marginal keels are either equally developed or the ventral keel is
sometimes reduced on the last chamber (e.g. Pl. 2, fig. 20).

5. The keels, sutures and umbilical flange can either be heavily beaded through-
out or beaded in the early part, thickened and limbate in the later part.

6. Chambers on the dorsal side 14-16, arranged in 3 whorls, generally dextrally
coiled (all studied specimens coiled dextrally).

7. Chambers in the last whorl 4-6, most commonly 5, large, moderately or
strongly elongated in the direction of coiling, increasing very rapidly in size.

8. The last chamber is either well-developed and constitutes +-4 of the test
(e.g. Pl. 2, fig. r ; Pl. 3, fig. 3), or is sometimes reduced in size, becoming
much smaller than the penultimate (PI. 2, fig. 2).

g. The umbilicus varies in shape, but is always wide, deep, and surrounded by a
raised umbilical flange which is either heavily beaded or just thickened and
limbate.

10. The surface is generally smooth but is sometimes covered by large scattered
papillae especially on the ventral side.

REMARKS. Globotruncana gagnebimi was first described by Tilev (1951) who
mentioned that it morphologically resembles G. pendens Vogler, G. ventricosa White
and G. lugeoni Tilev, but is quite distinct.

Bolli (1951) and Gandolfi (1955) described as G. ventricosa White, and G. ventricosa
ventricosa (White) respectively, forms which are actually G. gagnebini Tilev, as in
part reconsidered by Bolli (1957a). Gandolfi also described as G. arca caribica,
a form which appears to be transitional between G. gagnebini Tiley and G. aegyptiaca
aegyptiaca Nakkady, and is here considered to be a junior synonym of the former.
Gandolfi’s form closely resembles the specimen here figured, Pl. 3, figs. 1a—d.

Berggren (1962) considered G. gagnebini Tilev to be a junior synonym of G.
aegyptiaca aegyptiaca Nakkady, but the present study showed clearly that the
morphological features of the two species strongly warrant their separation in
spite of their apparent similarity. G. gagnebini is distinguished from G. aegyptiaca
aegyptiaca by its elongate, tightly coiled, ovoid test ; its greater number of chambers
in the last whorl which increase very rapidly in size ; its weakly lobate periphery,
more closely spaced keels and less rough surface.

Globotruncana gagnebint is believed to have evolved from G. ventricosa White by
reduction in the size of test and in the number of chambers in the last whorl, by
more rapid increase in the size of the chambers, and by the development of an
elongate test as well as a slightly rougher surface. The morphological characters and
stratigraphical distribution of the two species are strongly in favour of this propo-

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 113

sition which is substantiated by the occurrence of several transitional stages (see
Pl. 2, figs. 3a—d).

On the other hand, forms which can be morphologically considered as transitional
between G. gagnebini and G. aegyptiaca aegyptiaca were recorded, and may suggest
the evolution of the former into the latter. But the fact that the two species have
always been confused with each other does not allow one to distinguish precisely
their respective stratigraphical ranges which are generally considered to be the same.
However, the apparent morphological similarity of the two species may be due to
“ parallel evolution ”’ from two distinct but genetically related forms.

HypotyPes. P.45538.

HORIZON AND LOCALITY. Figured specimens, Pl.2, figs. 1a—d, 2a-d; Pl. 3,
fig. 6, from sample No. 16, W. El-Sharawna section ; Pl. 2, figs. 3a-d, which is a
transitional stage to G. ventricosa White, and PI. 3, figs. 3a-d, from sample No. 18,
W. El-Sharawna section ; Pl. 2, figs. 4a—-d, from sample No. 4, Abou Saboun section ;
Pl. 3, figs. ra—d, from sample No. 11, Gebel Owaina section.

STRATIGRAPHICAL RANGE. Globotruncana gagnebini was first described by Tilev
(1951) from the Maestrichtian of southeastern Turkey where it was recorded to
range throughout the stage. It was also recorded from the Maestrichtian of Trinidad
(Bolli 1951, 1957a) as ranging throughout the G. ganssert and the Abathomphalus
mayaroensis Zones.

In the Esna—Idfu region, G. gagnebini Tilev floods the Maestrichtian part of the
studied sections ; it is abundant in the G. fornicata Zone, floods the G. gansseri Zone
and is rare in the G. esnehensis Zone, where it dies out completely.

Globotruncana cf. gagnebini Tilev
(Pl. 3, figs. 2a—d)

RemMaArKS. The tendency of G. gagnebini Tilev to have a slightly raised dorsal
side was mentioned by Tilev (1951) and was observed in the present study. How-
ever, none of Tilev’s figures nor the typical specimens here studied, was found to have
a conical dorsal side. The form here described as G. cf. gagnebinz is closely related to
Tilev’s form, but differs only in having a gently coned, dorsal side. Morphologically,
this form should be considered separately, but because it was found to be rather
rare in the samples studied, it is provisionally described as G. cf. gagnebini.

HypotyPe. P.45539.

HORIZON AND LOCALITY. Figured specimens from sample No. 4, Abou Saboun
section.

STRATIGRAPHICAL RANGE. Globotruncana cf. gagnebini is rare in the Lower
Maestrichtian G. fornicata Zone and in the basal part of the Middle Maestrichtian
G. ganssert Zone of the Esna—Idfu region.

IT4 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

Globotruncana gansseri dicarinata Pessagno
(Pl. 5, figs. 4a—d)
1960 Globotyuncana (Rugotruncana) gansservi dicarvinata Pessagno: 103, pl. 2, figs. 9-11 ;

pl. 3, figs. 1-3 ; pl. 5, fig. 2.

DEscRIPTION. Test large, planoconvex, umbilico-convex, coiled in a very low
trochospire ; dorsal side flat, ventral side strongly protruding, equatorial periphery
roughly ovoid or rather quadrate, distinctly lobate, with two well-developed,
thickened, heavily beaded, widely spaced keels, reduced to a single keel on the last
chamber ; axial periphery truncate in the early part, subangular in the later ;
chambers on the dorsal side are not all clear because of the surface rugosity, but
appear to be 16 in number, arranged in 3 dextrally coiled whorls ; the initial chambers
are extremely small, indistinct, almost masked by the surface rugosity, increase very
slowly in size and are followed by globular to crescentic, weakly inflated chambers
which also increase slowly in size ; the last whorl is composed of 5 large, crescentic
chambers which increase rapidly in size ; on the ventral side the chambers are 5
large, angular conical and strongly protruding ; sutures on the dorsal side curved,
raised and heavily beaded ; on the ventral side they are straight, radial and depres-
sed ; umbilicus roughly pentagonal in outline, wide, deep, surrounded by a raised,
beaded, umbilical flange in the early part, which fades out gradually towards the last
chamber, and is covered by complex tegilla of which remnants are still preserved ;
primary apertures interiomarginal, umbilical ; tegilla with accessory apertures only
poorly preserved ; wall calcareous, perforate except for the imperforate keels,
peripheral band and tegilla ; surface rough, heavily papillose, nodose, or spinose in
the early part with the rugosity decreasing gradually towards the last chamber.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter = .0-50 mii.
Minimum diameter 0-35 Tin.
Thickness = 0-26) mam:

REMARKS. Pessagno (1960) stated that this subspecies differs from G. gansseri
ganssert Bolli in having a distinct double keel and well-developed rugosities in the
early stages. He also added that it is intermediate between Rugoglobigerina rugosa
subrugosa Gandolfi and G. gansseri gansseri Bolli and that it has evolved from the
former by dorsal flattening and the migration of the double-keel band to the dorsal
periphery. However, this subspecies appears to be more closely related to G.
gagnebim Tiley from which it differs only by the well developed surface rugosity.
Thus its assignment to G. ganssert may seem doubtful, as the last mentioned species
is characterized by its entirely single keel. However, the fact that Broénnimann &
Brown (1956) and Pessagno (1960) observed a double-keeled rugoglobigerine
nepionic stage in thin sections of G. ganssert ganssert, may support Pessango’s
hypothesis that the latter subspecies has evolved from G. gansseri dicarinata by the
gradual reduction of the ventral keel. The specimen here figured as G. ganssert
dicarinata Pessagno conforms well with the holotype, while the paratype figured
by Pessagno (1960) lacks the typically crescentic shape of the chambers on the

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT I15

dorsal side and the distinctly lobate periphery characteristic of the holotype.
Examination of topotype specimens, kindly presented by Dr. E. A. Pessagno, Jr.,
showed clearly that they are more like the figures of the paratype of Pessagno than
those of the holotype. The limited number of specimens found in the present study
does not allow the evolutionary history of this subspecies to be followed although its
evolution from G. gagnebini Tilev is not excluded, despite Pessagno’s statements.

HypotyPe. P.45540.

HoRIzoN AND LOCALITY. Figured specimen, from sample No. 16, Gebel Owaina
section.

STRATIGRAPHICAL RANGE. Globotruncana ganssert dicarinata was first described
by Pessagno (1960) from the Rio Yauco mudstone formation of Puerto Rico where it
was stated to be common in the lower part of the Maestrichtian G. tilevi Subzone,
and to constitute a particular faunal zonule, the G. ganssert dicarinata Zonule.

In the Esna—Idfu region, it occurs as a rare to common form in the Middle Maes-
trichtian G. gansseri Zone, and dies out completely in the basal part of the Upper
Maestrichtian G. esnehensis Zone.

Globotruncana gansseri gandolfii subsp. nov.
(Pl. 5, figs. 2a—d)
1955 Globotruncana gansseri ganssert Bolli ; Gandolfi : 69-70, pl. 6, figs. 8a—c, text-fig. 11D.

Dracnosis. A Globotruncana with small to large, quadrate, umbilico-convex
test ; weakly inflated chambers on dorsal side, slightly imbricate in last whorl ;
radial depressed ventral sutures, thin marginal keel slightly shifted towards dorsal
side ; rough surface.

DESCRIPTION. Test large, roughly quadrate in outline, planoconvex, umbilico-
convex, coiled in a very low trochospire ; dorsal side almost flat and somewhat
imbricate although the chambers are weakly inflated and slightly overlapping;
ventral side strongly inflated and distinctly protruding ; equatorial periphery
roughly quadrate, moderately lobate, with a single, delicately beaded keel which is
slightly shifted towards the dorsal side ; axial periphery subangular, subtruncate ;
chambers on the dorsal side about 17 in number, arranged in 23 dextrally coiled
whorls ; the initial chambers are exceedingly small, globular, slightly inflated and
almost masked by the surface rugosity ; they increase very slowly in size and are
followed by relatively larger, subglobular, slightly inflated chambers which increase
moderately in size ; the last whorl is composed of 43, large, roughly ovoid chambers
which increase moderately in size, although the last chamber is slightly smaller than
the penultimate ; on the ventral side the chambers are 44, large, subglobular,
strongly inflated and distinctly protruding ; sutures on the dorsal side slightly
curved, almost radial, raised and beaded, although the inflation of the chambers
makes them appear to be slightly depressed in part, especially towards the inner
whorl ; on the ventral side the sutures are straight, radial, and strongly incised

116 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

umbilicus roughly quadrate in outline, relatively wide, deep, and covered by complex
tegilla of which remnants are still preserved ; primary apertures interiomarginal,
umbilical ; tegilla with accessory apertures only poorly preserved ; wall calcareous,
perforate except for the imperforate keel and tegilla ; surface on the dorsal side
rough in the early part, covered with numerous small papillae which decrease
gradually towards the last chamber ; on the ventral side the surface is very rough,
heavily papillose or even nodose.

DIMENSIONS OF HOLOTYPE.

Maximum diamter = 0-48 mm.
Minimum diameter = 0°33 mm.
Thickness ='- 0-28 mm.

MAIN VARIATION.

1. Chambers 13-18, arranged in 23-3 whorls, generally dextrally coiled.

2. Chambers in the last whorl 4-5, flat to slightly inflated, slightly to moderately
imbricate, increasing slowly in size except for the last, which is either
slightly smaller or slightly larger than the penultimate.

3. The surface can either be rough throughout, heavily nodose or even spinose,
or it can be delicately papillose in the early part and smooth later.

REMARKS. Gandolfi (1955) described as G. ganssert ganssert Bolli from the
Colon shale of northeastern Colombia, a form which differs from the holotype of
Bolli (1951). Such a form is abundant in the samples studied; its morphological
characters and stratigraphical range warrant its separation from the central type
and therefore it is here considered as a new subspecies of G. ganssevi Bolli. It is
named G. ganssen gandolfi, after Dr. R. Gandolfi. It is believed to have evolved from
either G. gansseri ganssert (Bolli) or G. ganssert dicarinata Pessagno, as suggested by
the morphological features and stratigraphical ranges of these forms. On the other
hand, G. ganssert gandolfii is morphologically related to Globotruncana arabica sp.
nov. which appears slightly higher in the section and thus may possibly represent
its direct descendant.

HoLotyPe. P.4554I1.
PARATYPES. P.45542.

HoRIZON AND Locality. Holo- and paratypes, from sample No. 21, W. EIl-
Sharawna section, Esna—Idfu region.

STRATIGRAPHICAL RANGE. In the Esna—Idfu region G. ganssert gandolfii appears
as a common to a flood form in the upper part of the Middle Maestrichtian G. gansseri
Zone, and continues as a rare to a common form in the overlying G. esnehensis Zone
where it dies out completely immediately below the disconformity separating this
zone from the overlying basal Tertiary. All records of G. ganssert ganssert Bolli
from rocks younger than the Middle Maestrichtian (e.g. Gandolfi 1955 and Berggren
1962) most probably refer to the present subspecies.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 117

Globotruncana gansseri gansseri Bolli
(Pl. 5, figs. ta—d, Pl. 11, fig. 3)

1951 Globotruncana gansseri Bolli: 196, 197 ; pl. 35, figs. 1-3.
1956 Rugotruncana gansservi (Bolli) Bronnimann & Brown: 549-550; pl. 23, figs. 7-9 ;
text-fig. 23.
? 1960 Globotruncana monmouthensis Olsson : 50-51, pl. ro, figs. 22-24.
? 1960 Globotruncana (Rugotruncata) gansseri, Bolli; Pessagno : 102, pl. 4, fig. 11.

EMENDED DIAGNOSIS. A Globotruncana with large, planoconvex, umbilico-
convex test, large chambers increasing very rapidly in size in last whorl ; chambers
typically crescentic and strongly elongated in direction of coiling on dorsal side, and
angular conical, distinctly protruding on ventral side ; entirely single keel in last
whorl, curved, raised, beaded dorsal sutures and slightly curved, depressed ventral
ones ; very large umbilicus and moderately to heavily papillose surface in early part
of test.

DeEscriPTIon. Test large, planoconvex, umbilico-convex, coiled in a very low
trochospire ; dorsal side flat, ventral side strongly inflated and distinctly protruding ;
equatorial periphery roughly ovoid, moderately lobate, with a single well-developed,
beaded keel ; axial periphery truncate, angular acute ; chambers on the dorsal side
15, arranged in 23, dextrally coiled whorls ; the initial chambers are small, globular,
compressed ; they increase slowly in size and are followed by typically crescentic,
much flattened chambers which increase rapidly in size ; the last whorl is composed
of 5 large, crescentic, flattened chambers which are elongated in the direction of
coiling and increase rapidly in size ; on the ventral side the chambers are 5, large,
angular conical, strongly inflated and distinctly protruding ; sutures on the dorsal
side curved, raised and beaded ; on the ventral side the sutures are very slightly
curved to almost straight, radial and depressed ; umbilicus roughly pentagonal in
outline, very wide, deep, bordered by raised, beaded ridges and covered by complex
tegilla of which remnants are still preserved ; primary apertures interiomarginal,
umbilical ; tegilla, with accessory apertures, only poorly preserved ; wall calcareous,
perforate, except for the imperforate keel and tegilla ; surface smooth on the dorsal
side, coarsely papillose on the ventral, with the papillae becoming coarse and scattered
towards the last chamber.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter ==, «0-62.10.
Minimum diameter = O-47 tami.
Thickness == 6-90 mind,

MAIN VARIATION.

1. Chambers 14-16, arranged in 24-3 whorls, generally dextrally coiled (all
studied specimens coiled dextrally).

2. Chambers in the last whorl 43-5.

REMARKS. Globotruncana gansseri was first validly described by Bolli (1951)
although he had previously (1950) used the name without giving any description or

118 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

figure. Gandolfi (1955) described G. gansseri subganssert as a new subspecies thus
changing the name of Bolli’s form to G. gansseri gansseri. However, the form
figured by Gandolfi (1955) as G. ganssert ganssert Bolli was found to differ from the
holotype of Bolli and is thus considered here separately.

Broénnimann & Brown (1956) introduced Rugotruncana as a new genus and
included G. ganssevt Bolli in it. However, as mentioned above, Rugotruncana
Bronnimann & Brown 1956 is considered a junior synonym of Globotruncana Cush-
man 1927. These authors (1956) showed by thin sections of G. gansseri gansseri
that the early part of the test has two well-developed marginal keels in spite of the
entirely single-keeled last whorl. Pessagno (1960) also observed a double-keeled,
rugoglobigerine nepionic stage in thin sections of G. ganssert gansseri, but added that
some individuals may lack this initial double keel.

Olsson (1960) described as G. monmouthensis, a form which most probably belongs
to the present subspecies.

Globotruncana gansseri Bolli (1951) was found to include the following four distinct
subspecies :

Globotruncana ganssert ganssert Bolli 1951.
Globotruncana ganssert subganssert Gandolfi 1955.
Globotruncana ganssert dicarinata Pessagno 1960.
Globotruncana ganssert gandolfit subsp. nov.

However, because of its entirely double keel, G. gansseri dicarinata appears to
be morphologically distinct, despite the fact that thin sections of G. ganssert ganssert
showed a double-keeled nepionic stage. Further study may prove that it should
be treated separately although it has some features in common with the G. ganssert
group.

Gandolfi (1955) suggested the evolution of G. ganssert ganssert Bolli from G.
vosetta petterst Gandolfi which was said to appear in older strata and to die out
completely before the first appearance of G. gansseri ganssert. However, Pessagno
(1960) suggested the evolution of G. gansseri gansseri from G. ganssert dicarinata,
while the present study favours its evolution from G. rosetta rosetta (Carsey). On
the other hand, G. gansseri ganssert might possibly have evolved in two directions,
one leading to G. gansseri subganssert and the other to G. gansseri gandolfit.

HypotyPe. P.45543.

HORIZON AND LOCALITY. Figured specimen, from Sample No. 18, W. El-Shar-
awna section.

STRATIGRAPHICAL RANGE. Globotruncana gansseri gansseri was first described
by Bolli (1951) from the Maestrichtian Lantern marl, Guayaguayare formation of
Trinidad and all subsequent references restricted its range to the Maestrichtian.

In the Esna—Idfu region, G. ganssert ganssert appears in the basal part of the
Pecten (Chlamys) mayereyman marl (Pecten farafraensis marl) ; it floods this rock unit
and the basal part of the overlying shale member, characterizing a particular faunal
zone, the G. ganssert Zone. It continues in the Upper Sharawna shale, fading out

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 119

gradually upwards in the section and dies out completely in the basal part of the
overlying G. esnehensis Zone.

Bolli (19574) recognized the G. ganssert Zone in the Maestrichtian of Trinidad,
where he considered it to start slightly above the base of the Maestrichtian. How-
ever, Bronnimann & Brown (1956) considered the range of this species to be Lower
to Middle Maestrichtian, while the G. gansseri Zone is here considered to represent
the Middle Maestrichtian only.

Globotruncana gansseri subgansseri Gandolfi
(Pl. 5, figs. 3a—d)

1955 Globotruncana ganssert subgansseri Gandolfi : 70, pl. 6, figs. 7a-c.

DESCRIPTION. Test small, subcircular in outline, almost planoconvex, umbilico-
convex, coiled in a low trochospire ; dorsal side flat although the early chambers are
slightly inflated and weakly raised above the circumambient, last whorl ; ventral side
strongly inflated and distinctly protruding ; equatorial periphery subcircular,
moderately lobate, with a single, delicately beaded marginal keel ; axial periphery
acute ; chambers on the dorsal side 18, arranged in 3 dextrally coiled whorls ; the
initial ones are very small, globigerine and weakly inflated, they increase slowly in
size and are followed by slightly larger, globular, inflated chambers which increase
moderately in size ; the last whorl is composed of 6 relatively large, crescentic
chambers which increase slowly in size except for the last one which is slightly
smaller than the penultimate ; on the ventral side the chambers are 6, subglobular,
strongly inflated, distinctly protruding and increase slowly in size ; sutures on the
dorsal side curved, slightly raised and delicately beaded ; on the ventral side they
are radial and strongly depressed ; umbilicus roughly hexagonal in outline, relatively
large, deep and covered by complex tegilla of which remnants are still preserved ;
primary apertures interiomarginal-umbilical ; tegilla with accessory apertures only
poorly preserved ; wall calcareous, perforate, except for the imperforate keel,
peripheral band and tegilla ; surface rough, especially on the ventral side where it is
coarsely papillose in the early part, with the roughness decreasing gradually towards
the last chamber ; the papillae sometimes taper out simulating thick spine-like
projections especially along the periphery.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter = 0:35 mm.
Minimum diameter =" 0-29 mum.
Thickness = 0:24 mm. (of last chamber)

REMARKS. Globotruncana gansseri subganssert was first described by Gandolfi
(1955) who remarked that this subspecies differs from G. gansseri gansseri in having
a smaller test, a greater number of chambers in the last whorl, more inflated chambers,
and a less evident keel.

Globotruncana gansseri subganssert is believed to have evolved from G. gansseri

120 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

ganssert Bolli, and may possibly represent a transitional stage between the latter and
G. lugeont Tilev, although no direct evidence was recorded.

HypotyPe. P.45544.

HORIZON AND LOCALITy. Figured specimen from sample No. 16, Gebel Owaina
section.

STRATIGRAPHICAL RANGE. Gandolfi (1955) described G. ganssert subganssernt
from the Colon shale of northeastern Colombia where its range was described as

fairly rare in the uppermost Siphogenerinoides bramletter Zone which he considered to
be of Maestrichtian age.

In the Esna—Infu region, G. ganssert subganssert appears as a rare to common form
in the Middle Maestrichtian G. gansseri Zone. It increases gradually upwards in
the section to flood the basal part of the overlying G. esnehensis Zone and then dies
out completely near the middle part of this zone.

Globotrunana havanensis Voorwijk

1937. Globotvuncana havanensis Voorwijk : 195, pl. 1, figs. 25, 26, 29.

Globorotalia pshadae Keller : 99, pl. 2, figs. 4-6.

1951 Globotruncana citae Bolli: 197, pl. 35, figs. 4-6.

Globotruncana citae Bolli; Papp & Kiipper : 38, pl. 1, figs. 4a—c.

Globorotalia pshadae Keller ; Subbotina : 204, pl. 16, figs. 1a—6c.

1954 Globotvuncana citae Bolli; Ayala: 387, pl. 3, figs. 2a—c.

1954 Globotruncana havanensis Voorwijk ; Ayala : 396, pl. 6, figs. 2a-c.

1955 Globotruncana citae Bolli: Gandolfi: 51, pl. 3, figs. 11a-c.

1956 Globotrvuncana citae Bolli ; Knipscheer (in Ganss & Knipscheer) : 624, pl. 2, figs. 3a—-c.

1956 Rugotruncana havanensis (Voorwijk) Brénnimann & Brown: 552, pl. 22, figs. 4-6,
pl. 24, fig. 5.

1956b Marginotruncana citae (Bolli) Hofker : 334, text-fig. 25.

1956c Marginotruncana citae (Bolli) ; Hofker : 79, text-fig. 72.

1957 Globotyuncana (Globotruncana) citae Bolli; Edgell: 111, pl. 1, figs. 13-15.

1960a Globotvuncana citae Bolli; Hofker : 225, text-figs. 20a—c.

1960 Globorotalia pshadae Keller ; Vinogradov : 307, pl. 2, figs. 15a—16b.

1962 Pyraeglobotruncana (Praeglobotruncana) havanensis (Voorwijk) Berggren : 26-30, pl. 7,

figs. 1a—c.

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REMARKS. The taxonomic position of this species has been very much confused ;
it was defined as a Globotruncana by Voorwijk (1937), as a Globorotalia by Keller
(1946), Subbotina (1953) and Vinogradov (1960), as a Rugotruncana by Bronnimann
& Brown (1956) and Pessango (1960), as Marginotruncana by Hofker (19560, c) and
as Praeglobotruncana by Bolli (1957a) and Berggren (1962). However, the few
specimens recorded in the present study clearly show that the aperture is interio-
marginal, umbilical, covered by complex tegilla of which remnants are still preserved,
and thus prove that the species should be assigned to the genus Globotruncana.

HypotyPes. P.45657-58.

HoRIzON AND Locality. Hypotypes from sample 23, Gebel Owaina section.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 121

STRATIGRAPHICAL RANGE. Globotruncana havanensis was first described by
Voorwijk (1937) from the Upper Cretaceous of Habana, Cuba. It was also recorded
from the Maestrichtian of the Caucasus (Keller 1946 and Subbotina 1953), the
Maestrichtian of Trinidad (Bolli 1951, 1957a), of Austria (Papp & Kupper, 1953),
of northeastern Colombia (Gandolfi 1955), of Bavaria (Knipscheer 1956), of Texas
and of Cuba (Bronnimann & Brown 1956), of northwestern Germany and of Holland
(Hofker 19560, c), of Australia (Edgell 1957), of Romania (Vinogradov 1960) and of
southern Scandinavia (Hofker 1960a and Berggren, 1962).

In the Esna—Idfu region, G. havanensis occurs as a rare form throughout the Mae-
strichtian, increasing gradually upwards in the section, and dying out completely
below the disconformity separating the Maestrichtian from the overlying Danian.

Globotruncana leupoldi Bolli
(Pl. 1, figs. 4a—c)
1945 Globotruncana leupoldi Bolli : 235, pl. 9, fig. 17 ; text-fig. 1, figs. 25, 26.

DESCRIPTION. Test medium-sized, subcircular in outline, biconvex, coiled in
a moderately high trochospire ; dorsal side broadly convex, moderately raised,
ventral side convex and moderately inflated ; equatorial periphery subcircular,
distinctly lobate, with two well-developed, thickened, delicately beaded and widely
spaced marginal keels, becoming single on the last chamber only ; axial periphery
truncate in the early part, angular and distinctly acute in the later part ; chambers
on the dorsal side 16, arranged in 3 dextrally coiled whorls ; the initial chambers are
small, inflated, globigerine, increasing moderately in size and followed by typically
crescentic, petaloid chambers which increase slowly in size as added ; the last whorl
is composed of 5 large, typically crescentic, petaloid chambers which are elongated
in the direction of coiling and increase slowly in size ; on the ventral side the chambers
are 5, large, roughly ovoid and distinctly outlined with horseshoe-shaped, beaded
ridges and increase slowly in size ; sutures on the dorsal side are curved, raised and
beaded ; on the ventral side they are strongly curved forward, thickened, raised and
beaded ; umbilicus pentagonal in outline, wide, deep, bordered by raised, beaded
ridges and covered by complex tegilla of which remnants are still preserved ; primary
apertures interiomarginal, umbilical ; tegilla with accessory apertures only poorly
preserved ; wall calcareous, perforate, except for the imperforate keels, peripheral
band and tegilla ; surface smooth.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter = 0°45 itn,
Minimum diameter ==, OF37 im:
Thickness == 6-22 tin.

REMARKS. Bolli (1945) described G. Jewpoldi from thin sections only and included
in its synonymy some of the forms previously described by de Lapparant (1918)
as Rosalina linnei d’Orbigny “ type 5’ and Rosalina stuarti, although the latter is a
completely distinct form. He also considered some of the forms described by Vogler

122 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

(1941) as Globotruncana linnez stuarti Vogler and G. linnet marginata (Reuss) to belong
to G. leupoldt.

Reichel (1950) considered G. leupoldi as a junior synonym of G. arca (Cushman)
while Papp & Kupper included it in the synonymy of G. fornicata Plummer, and
Broénnimann & Brown (1956) followed by Berggren (1962) in that of G. rosetta
(Carsey). However, Globotruncana leupoldi is too remote to be related to either
G. fornicata or G. rosetta. It is distinguished from typical G. arca, from which it is
thought to have evolved, by its smaller, slightly compressed test, fewer chambers,
less beaded keels and sutures, sharply acute axial periphery on the last chamber and
truncate one on the early chambers, its flattened petaloid last chambers on the
dorsal side, its single keel on the last one or two chambers and its perfectly smooth
surface.

The form described by Olsson (1960) as G. lewpoldi is probably G. arca or is tran-
sitional to it.

HypotyPe. P.45545.

HoRIZON AND LOCALITY. Figured specimen, from sample No. 18, W. El-Sharaw-
na section.

STRATIGRAPHICAL RANGE. Globotruncana lewpoldi was described by Bolli (1945)
from the Wangschichten limestone of Switzerland where it was found to range
throughout the Upper Campanian—Maestrichtian.

In the Esna—Idfu region G. leupoldi ranges throughout the G. fornicata and the
G. ganssert Zones. It fades out gradually towards the top part of the latter zone
and dies out completely in the basal part of the overlying G. esnehensis Zone.

Globotruncana lugeoni Tilev
(Pie 6, figs. 1¢-—d ;_ Pl. 1x, fig. 2)

1951 Globotrvuncana lugeoni Tilev : 41-46, pl. 1, figs. 5, 6, text-figs. 1oa—c, 11a—d, ? 12a-e.
(See also Tilev 1952 where figures are repeated.)

DESCRIPTION. Test large, planoconvex, coiled in a very low trochospire ; dorsal
side almost flat and slightly imbricate although the chambers are slightly inflated
and moderately overlapping ; ventral side strongly inflated and distinctly protruding ;
equatorial periphery roughly ovoid, elongate, slightly lobate, with a single well-
developed, heavily beaded marginal keel which is slightly shifted towards the dorsal
side ; axial periphery subangular ; chambers on the dorsal side about 18, arranged in
3 dextrally coiled whorls, increasing very slowly in size ; initial chambers small
subglobular, weakly inflated and almost masked by the surface rugosity ; they are
followed by slightly larger subglobular chambers ; the last whorl is composed of 6
subcircular, weakly inflated chambers ; on the ventral side the chambers are 6,
subglobular, strongly inflated, distinctly protruding and increase so slowly in size
that they all appear to be roughly equal except for the last ; sutures on the dorsal side
slightly curved, depressed in the early part, strongly curved, raised, thickened and
heavily beaded in the later part, although the slight inflation of the chambers makes

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 123

them appear slightly depressed towards the inner whorl ; on the ventral side the
sutures are radial and strongly incised ; umbilicus roughly hexagonal in outline,
moderately wide, deep and covered by complex tegilla of which remnants are still
preserved ; primary apertures interiomarginal, umbilical ; tegilla, with accessory
apertures, only poorly preserved ; wall calcareous, perforate, except for the imperfo-
rate keel and tegilla ; surface rough, heavily nodose in the early part especially on
the ventral side, with the roughness decreasing gradually towards the last chamber.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter == 0°43 cam;
Minimum diameter =, 0:34 mm,
Maximum thickness = 0:26 mm. (Thickness of last chamber)

MAIN VARIATION.

I. Chambers 13-18, arranged in 2}-34 whorls, generally dextrally coiled (all
specimens studied coiled dextrally).

2. Chambers in the last whorl 4-7.

Remarks. Bronnimann & Brown (1956) followed by Berggren (1962) considered
this species to be a junior synonym of G. gansseri gansseri Bolli. However, the
present study showed clearly that the two forms are morphologically distinct and
should be treated separately.

The evolutionary history of G. lugeoni Tilev is not clear, but it might have evolved
from G. ganssert ganssert, although no direct evidence was recorded.

Tilev (1951, 1952) also described as G. lugeont var. angulata, a form which appears
to be quite distinct from the holotype of G. /ugeoni and the studied hypotypes. It
appears to be more closely related to G. stwarti stuarti (de Lapparent), although it
lacks the characteristic shape of the chambers of the latter species on the ventral side.
Forms identical with this variety were recorded in the samples studied, but being very
rare they are not described for the time being.

Hypotype. P.45546.

HORIZON AND LOCALITY. Figured specimen, from sample No. 15, Gebel Owaina
section.

STRATIGRAPHICAL RANGE. Tilev (1951, 1952) recorded G. lugeont from the
Maestrichtian of southeastern Turkey stating that its range is more precisely
considered as Middle Maestrichtian. In the Esna—Idfu region, G. lugeom Tilev
occurs as a rare form in the G. gansseri Zone. It gradually increases upwards in the
section to flood the upper part of this zone and then fades out gradually in the basal
part of the overlying G. esnehensis Zone, where it dies out completely.

Globotruncana mariai Gandolfi

1941 fosalinella globigerinoides Marie : 239, pl. 36, figs. 338a-c.
1941 Rosalinella globigerinoides var. sublaevigata Marie : 240, pl. 36, figs. 339a-c.
1955 Globotruncana mariai Gandolfi : 33.

124 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

REMARKS. Marie (1941) described Rosalinella globigerinoides as a new species
from the Campanian, “ Belemnitella mucronata chalk’’ of the Paris Basin. As
Rosalinella Marie, is a junior synonym of Globotruncana Cushman 1927, the name of
the present species was automatically changed to Globotruncana globigerinoides
(Marie) where it became a junior homonym of Globotruncana globigerinoides Brotzen
1936, which in its turn is a junior synonym of G. cretacea (d’Orbigny) 1840.

Gandolfi (1955) changed the name of the present species to Globotruncana maniai
nom. nov. Apparently he named the species after Dr. P. Marie, who first described
it, and the spelling should have been mariet. Unfortunately, Banner & Blow (1960)
proposed the name G. mariet for G. cretacea Cushman 1938, which itself is a junior
homonym of G. cretacea (d’Orbigny) 1840.

As neither of the names can be changed according to the rules of zoological
nomenclature, they are both applied here in spite of the confusion which may result.

Globotruncana mariat is distinguished by its peculiarly shaped, segmented, imbricate
double keel and wide peripheral band. Marie (1941) also described as R. globi-
gerinotdes var. sublaevigata, a form which only differs from the central type in having
the two marginal keels unequally projecting. Such a minor variation was found to
be unworthy of distinction and thus G. globigerinoides var. sublaevigata is included
here within the central type.

HyPotyPe. P.45547.
HORIZON AND LOCALITY. Hypotype from sample No. 4, Abou Saboun section.

STRATIGRAPHICAL RANGE. This species was originally described from the
Campanian of the Paris Basin (Marie 1941). It occurs as a rare to common form in
the Lower Maestrichtian G. fornicata Zone of the studied sections, and dies out
completely in the top part of this zone.

Globotruncana mariei Banner & Blow

1931 Globotyuncana avca (Cushman) ; Cushman : 59, pl. 11, figs. 6a-—c.

1931 Globotruncana arca (Cushman) ; Plummer, (pars) : 195, pl. 13, figs. 7-8c ; non figs.
ga-—c, I1a—c.

1936 Globotyuncana ayca (Cushman) ; Cushman: 419, pl. 1, figs. 14a-c.

1938 Globotyuncana cretacea Cushman ; 67, pl. 11, figs. 6a—c.

1939 Globotruncana cretacea Cushman ; Cushman : 92, pl. 16, figs. 8a—c.

1946 Globotruncana cretacea Cushman ; Cushman : 151, pl. 62, figs. 7a-c.

1951 Globotruncana cretacea Cushman ; Tilev (pars) ; 62-67, text-figs. 21a—-d, non 20a-d.
(See also Tilev 1952 where figures are repeated.)

1954 Globotvuncana cretacea Cushman ; Nakkady & Osman : 79, pl. 19, figs. 1oa—c.

1960 Globotrvuncana mariei Banner & Blow : 8.

REMARKS. Globotruncana mariei was first described by Cushman (1931) as
Globotruncana arca (Cushman). The same author (1938), realizing the difference
between this form and G. arca, considered it as a distinct species and named it
G. cretacea Cushman.

Tilev (1951, 1952) stated that although Cushman (1938) had described his G.
cretacea as “‘ usually having a single keel’”’, the holotype, as figured by Cushman

|

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 125

was shown to have two closely spaced keels. He also noticed that in the specimens
he studied from the Maestrichtian of southeastern Turkey, there were forms with
double and single keels. He also considered G. rosetta rosetta (Carsey) as a junior
synonym of the present species in spite of its priority.

Brénnimann & Brown (1956) confirmed Tilev’s earlier observation stating that
“In an examination of the holotype of G/t. cretacea Cushman, two keels, very close
together, were observed in all chambers of the last whorl’. These two authors also
considered the present species to be intermediate between G. lapparenti Brotzen and
G. rosetta (Carsey).

Banner & Blow (1960) proved Globigerina cretacea d’Orbigny, 1840, to be a true
Globotruncana, and thus changed its name to Globotruncana cretacea (d’Orbigny)
whereby Globotruncana cretacea Cushman 1938, became a junior homonym, which
they renamed Globotruncana mariet nom. nov.

Globotruncana marie: is distinguished by its medium-sized, planoconvex to
unequally biconvex test, its chambers which increase rapidly in size in the last whorl,
its very closely spaced keels, and strongly overlapping chambers on the ventral side,
and by its smooth test and somewhat rougher keels.

Contrary to Tilev’s observation (1951, 1952), G. marei is quite distinct from G.
rosetta rosetta (Carsey), although Bronnimann & Brown (1956) stated that it seems to
be an incipient form of G. rosetta.

Nakkady (1951a@) described as G. cretacea Cushman from Duwi, Mellaha, Durba
and Danilli sections, Egypt, forms which include G. stuarti stuartiformis Dalbiez,
G. aegyptiaca aegyptiaca Nakkady and G. gagnebim Tilev, as examination of his
specimens (B.M. N.H., P.41782) has revealed.

Nakkady also figured as G. pseudocretacea n.sp., a form which most probably
belongs to G. gagnebini Tilev, or is transitional between it and G. ventricosa White,
as examination of his type specimens (B.M.N.H., P.41783-84) has revealed. How-
ever, Berggren (1962) wrongly considered G. pseudocretacea to be a nomen nudum
and stated that Nakkady’s specimens were related to G. rosetta rosetta (Carsey).

HypoTyPe. P.45548.

HORIZON AND LOCALITY. Hypotype from sample No. 18, W. El-Sharawna
section.

STRATIGRAPHICAL RANGE. Globotruncana mariet was first described from the
Upper Campanian, Selma chalk of Tennessee. Most records show that it ranges
throughout the Upper Campanian and the Maestrichtian.

In the Esna—Idfu region, G. mariet occurs as a common form throughout the
Maestrichtian, G. fornicata, G. ganssert and G. esnehensis Zones, being most common
at the base and fading out gradually upwards in the section.

Globotruncana orientalis sp. nov.
(Pl. 12, figs. 4a—d)

Diacnosis. A Globotruncana with broadly arched dorsal side and almost flat
ventral one, two closely spaced keels in early part, reduced to one in the last chambers;

126 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

curved, raised, beaded sutures, wide umbilicus and horseshoe-shaped ridge of beads
bordering each chamber on ventral side.

DESCRIPTION. Test large, almost circular in outline, coiled in a relatively high
trochospire ; dorsal side broadly convex, ventral side flat although the chambers are
very slightly inflated ; equatorial periphery almost circular, slightly lobate ; axial
periphery angular, acute, with two heavily beaded keels on the early chambers of the
last whorl, reduced to a single, well-developed, distinctly beaded keel in the last
chambers ; chambers on the dorsal side 18 (17 + 1 broken), arranged in 3 dextrally
coiled whorls and slowly and regularly increasing in size ; the initial chambers are
small, inflated and globigerine, while later chambers are typically crescentic, slightly
flattened and elongated in the direction of coiling, the last whorl is composed of 6
large, typically crescentic chambers ; on the ventral side the chambers are 6, ovoid,
very weakly inflated, slightly overlapping, distinctly outlined with heavily beaded
horseshoe-shaped rims, and increase so slowly in size that they all appear to be roughly
equal ; sutures on both sides curved, raised, thickened and heavily beaded ; umbili-
cus roughly hexagonal in outline, wide, deep, surrounded by slightly raised, heavily
beaded ridges, and covered by complex tegilla of which remnants are still preserved ;
primary apertures interiomarginal, umbilical ; tegilla with accessory apertures only
poorly preserved ; wall calcareous, perforate, except for the imperforate keels,
peripheral band and tegilla ; surface generally smooth.

DIMENSIONS OF HOLOTYPE.

Maximum diameter = 20°50. iim:
Minimum diameter = 0-45 mm.
Thickness ==) 0-25 unio.

MAIN VARIATION.
1. Chambers on the dorsal side 18-21, arranged in 3-34 whorls, generally dextrally
coiled.
2. The last whorl is composed of 5—7 chambers which are large, crescentic and
increase slowly in size.
3. Insome specimens the ventral keel is completely reduced and the test becomes
entirely single keeled at least throughout the last whorl.

REMARKS. Globotruncana orientalis is morphologically similar to G. leupoldi
Bolli, G. conica White, G. esnehensis Nakkady & Osman and to G. sharawnaensis
sp. nov. However, it is distinguished from G. leupoldi by its flat ventral side, much
narrower peripheral band and less lobate equatorial periphery. It differs from G.
conica White by its less conical dorsal side, its early double keel and the horseshoe-
shaped ridges on the ventral side. Globotruncana esnehensis is entirely single keeled
and has strongly depressed ventral sutures, while G. sharawnaensis sp. nov. is single
keeled in the early part becoming double keeled later, has depressed ventral sutures
and a rougher surface.

The forms desribed by Cita (1948) and Pessagno (1962) as G. conica White most
probably belong to tue present species.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 27,

Globotruncana orientalis sp. nov. has possibly evolved from G. avca (Cushman) by
the flattening of the ventral side and the reduction of the ventral keels on the last
chambers. This is substantiated by the fact that such tendencies were clearly
observed in specimens of G. avca (Cushman). On the other hand, G. oventalis has
probably evolved into G. esnehensis Nakkady & Osman, although no direct evidence
was recorded.

HoLotyPe. P.45549.
PARATYPES. P.45550.

HORIZON AND LocaLity. Holo- and paratypes from sample No. 18, W. El-Sharaw-
na section.

STRATIGRAPHICAL RANGE. Globotruncana orientalis sp.nov. appears as a common
to abundant form in the Lower Maestrichtian G. fornicata Zone of the sections
studied. It continues as an abundant form in the overlying G. gansseri Zone,
fading out gradually towards its top, and dies out completely in the basal part of the
G. esnehensis Zone.

Globotruncana rosetta pettersi Gandolfi

1955 Globotruncana rosetta pettersi Gandolfi : 68, pl. 6, figs. 3a—4c, text-fig. 11a.
1961 Globotruncana cf. rosetta pettevst Gandolfi ; Corminboeuf : 113-114, pl. I, figs. 3a—c.

REMARKS. Globotruncana rosetta pettersi was first described by Gandolfi (1955) as
a new subspecies from the lower Colon shale of northeastern Colombia where he
considered its range as Campanian. He stated that the form is entirely single
keeled, but examination of topotype specimens kindly sent by him to the present
author, showed forms with 2 keels on the early part of the last whorl, becoming
single keeled on the later chambers, and others with an entirely single keeled last
whorl. The entirely single keeled form is similar to the G. gansseri group, especially
to G. ganssert gandolfit subsp. nov. from which it is only distinguished by its smooth
surface. Gandolfi also stated that G. rosetta pettersi was found to disappear when the
first G. gansseri gansseri starts, but in the present study G. rosetta pettersi occurs as a
common form in the lower part of the G. ganssert Zone. It was neither recorded in
the underlying G. fornicata Zone nor in the upper part of the G. gansseri Zone. This
clearly indicates that the range of this subspecies is only Middle Maestrichtian, while
Gandolfi considered it as Campanian. However, as previously mentioned, the
Colon shale, which Gandolfi considers as Campanian—Maestrichtian, most probably
belongs to the Maestrichtian alone, as suggested by its planktonic foraminiferal
content. This is substantiated by the fact that the present subspecies was also
recorded from the Maestrichtian of Switzerland as G. cf. rosetta petterst Gandolfi by
Corminboeuf (1961).

HypotypPe. P.45551.

HORIZON AND LOCALITY. Hypotype from sample No. 23 W. El-Sharawna section.

128 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

Globotruncana rosetta rosetta (Carsey)
(Pl. 8, figs. 3a—d)
1926 Globigerina rosetta Carsey : 44, pl. 5, figs. 3a—c.
1931 Globotyuncana ayca (non Cushman) ; Plummer (pars) : 195, pl. 13, figs. 9a—-c, 11a—c
(non figs. 7a—c, 8a-c).
1937a Globotyuncana rosetta (Carsey) Glaessner : 39, pl. I, figs. 12a—c.
1951 Globotruncana rosetta (Carsey) : Bandy : 5009, pl. 75, figs. 4a—c.
1951 Globotyuncana cretacea Cushman ; Tilev (pars) 62-67, text-figs. 2oa-d, non 21a—d
(see also Tiley 1952 where figures are repeated).
1954 Globotruncana rosetta (Carsey) ; Nakkady & Osman : 84, pl. 19, figs. 7a-c.
1955 Globotruncana rosetta rosetta (Carsey) ; Gandolfi : 66-67, pl. 6, figs. 1a—c, text-figs. Ioa—c.
1955 Globotvuncana bollii Gandolfi : 62-63, pl. 5, figs. ra—c.
1956 Globotruncana rosetta (Carsey) : Brénnimann & Brown : 545-546, pl. 21, figs. 11-13.
1962 Globotruncana rosetta (Carsey) : Barr : 575, pl. 70, figs. 4a-—c.

ou ow

DeEscriPTION. Test large, planoconvex, coiled in a very low trochospire ; dorsal
side almost flat, ventral side distinctly protruding ; equatorial periphery subcircular,
moderately lobate, with two very closely spaced keels on the early part of the last
whorl reduced to a single keel on the later chambers ; axial periphery angular with
the ventral side almost at right angles to the flat periphery ; chambers on the dorsal
side 18, arranged in 3 dextrally coiled whorls ; the initial chambers are small, inflated,
globigerine, increasing slowly in size, and followed by typically crescentic, flattened
chambers which increase moderately in size ; the last whorl is composed of 6,
relatively large, typically crescentic, flattened chambers which increase slowly in
size ; on the ventral side the chambers are 6, relatively large, angular conical,
strongly inflated, slightly overlapping, distinctly protruding and increase so slowly
that they appear to be all roughly equal in size ; sutures on the dorsal side curved,
slightly raised and delicately beaded with the beading fading out gradually towards
the last chamber ; on the ventral side the sutures are radial and slightly depressed ;
umbilicus roughly stellate in outline, relatively wide, deep, bordered by delicately
beaded ridges and covered by complex tegilla of which remnants are preserved ;
primary apertures interiomarginal, umbilical ; tegilla, with accessory apertures, only
poorly preserved ; wall calcareous, perforate, except for the imperforate keels,
peripheral band and tegilla ; surface delicately papillose especially on the ventral
side and in the early part becoming smoother towards the last chamber.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter = O-52\mIm.
Minimum diameter = O47 mm:
Maximum thickness = 0730 nim:

VARIATION. The main variation observed is in the degree of flattening of the
dorsal side, protrusion of the ventral side, and surface rugosity.

REMARKS. Globotruncana rosetta rosetta was first described by Carsey (1926) as
Globigerina rosetta n.sp. White (1928) transferred this species to the genus Globo-
truncana although his figured specimen probably belongs to the G. stuarti group.
Plummer (1931) considered the present species to belong to G. avca (Cushman)

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 129

suggesting that the two keeled specimens are juvenile forms while the single keeled
ones are mature. Since then G. vosetta rosetta has been quite often confused with
G. arca Cushman, G. marginata (Reuss), G. stuwarti (de Lapparent) and G. cretacea
Cushman (= G. mariet Banner & Blow 1960).

Tilev (1951, 1952) included G. rosetta rosetta (Carsey) in the synonymy of G.
cretacea Cushman 1938 (= G. mariei Banner & Blow 1960) although the former has
priority. Brénnimann & Brown (1956) partially substantiating Tilev’s observation,
stated that ““ Examination of the holotype of Globotruncana rosetta (Carsey), in the
Carsey collection at the University of Texas, reveals that it possesses two keels in
the early chambers of the last whorl which are very close together. In the ante-
and penultimate chambers the two keels join”. These two authors also added
“In an examination of the holotype of Gilt. cretacea Cushman, two keels, very close
together, were observed in all chambers of the last whorl. It is intermediate
between Git. lapparenti Brotzen and Git. rosetta (Carsey). It seems to be an incipient
form of Git. rosetta, for all transitions exist between forms corresponding to the holo-
types of Git. rosetta and Git. cretacea. We suggest that the forms which exhibit two
keels, close together in all chambers of the last whorl be referred to Git. cretacea
Cushman, and that the forms which exhibit two keels close together in the early
chambers of the last whorl and only one keel in the final one or two chambers be
referred to Gilt. rosetta (Carsey)’’. They also included G. lewpoldi Bolli in the
synonymy of G. rosetta (Carsey). However, the present study has clearly shown
that G. rosetta rosetta (Carsey), G. cretacea Cushman (= G. mariet Banner & Blow)
and G. leuwpoldi Bolli are separate and distinct forms.

Gandolfi (1955) described as new subspecies of G. rosetta (Carsey), two distinct
forms which he named Globotruncana rosetta insignis Gandolfi and Globotruncana
rosetta pettersi Gandolfi, thus changing the name of the present form to Globotruncana
rosetta rosetta (Carsey). He did not state whether his G. rosetta rosetta had a double
keel on the early part or not, and his G. rosetta insigmis appears to be synonymous with
G. fareedi sp. nov., as mentioned earlier (p. 101). Gandolfi also described as G.
bollit n. sp., a form which may possibly be a junior synonym of G. rosetta rosetta
(Carsey). Moreover, he suggested that G. rosetta rosetta evolved from G. thalmanni
thalmanm: through G. bollit into G. rosetta pettersi and G. rosetta insignis, while
Berggren (1962) suggested that G. rosetta evolved from G. mariei. However, the
evolutionary development of G. rosetta rosetta is not yet clearly understood. It may
have evolved from G. concavata (Brotzen) or from G. ventricosa White as suggested
by the morphological features and stratigraphical ranges of these species, but no
direct evidence was recorded. On the other hand, G. rosetta rosetta probably evolved
into G. gansseri gansseri (Bolli) as well as giving rise to G. rosetta pettersi.

HypotypPe. P.45552.

HORIZON AND LOCALITy. Figured specimen from sample No. 16, W. El-Sharaw-
na section.

STRATIGRAPHICAL RANGE. Carsey (1926) described the holotype of G. rosetta
from the upper Taylor marl (Upper Campanian of Texas), but apparently she had

130 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

confused this form with various other species and thus confused its range which she
stated to be Cenomanian—Maestrichtian. However, all reliable records show that
the present subspecies ranges throughout the Upper Campanian—Middle Maestrich-
tian only. In the Esna—Idfu region, G. rosetta rosetta (Carsey) occurs as an abundant
form in the Lower Maestrichtian G. fornicata Zone, decreasing gradually upwards in
the section and becoming common or rare in the lower part of the overlying G.
ganssert Zone, where it dies out completely.

Globotruncana sharawnaensis sp. nov.
(Pl. 12, figs. 3a—d)

DiaGnosis. <A Globotruncana with large, spiroconvex test, single keel in early part
becoming double in last chamber, depressed ventral sutures and delicately papillose
surface on ventral side.

DESCRIPTION. Test large, coiled in a high trochospire ; dorsal side broadly
convex and highly arched, ventral side almost flat, very slightly raised and weakly
inflated ; equatorial periphery subcircular, slightly lobate, with a single, well-
developed, beaded keel on the early chambers of the last whorl and two distinct,
closely spaced, beaded keels on the last chamber ; axial periphery angular in the
early part, truncate on the last chamber, where the two marginal keels are very close
and enclose a very narrow peripheral band ; chambers on the dorsal side 21, arranged
in 3 dextrally coiled whorls and increase slowly in size ; the initial chambers are small,
inflated, globigerine, and are followed by roughly quadrangular to crescentic cham-
bers ; the last whorl is composed of 63, large chambers, which are generally crescentic
to quadrilateral ; on the ventral side the chambers are 63, roughly ovoid to somewhat
quadrangular, weakly inflated, slightly overlapping, and increase slowly in size;
sutures on the dorsal side are curved, raised and beaded in the early part and short,
very slightly curved to almost straight, raised and beaded in the later ; on the ventral
side the sutures are almost straight, radial and depressed in the early part, slightly
curved forward and depressed later ; umbilicus polygonal in outline, wide, deep,
surrounded by slightly raised, delicately beaded ridges and covered by complex,
tegilla of which remnants are still preserved ; primary apertures interiomarginal,
umbilical ; tegilla with accessory apertures only poorly preserved ; wall calcareous
perforate except for the imperforate keels, peripheral band and tegilla ; surface
smooth on the dorsal side, papillose on the ventral, with the papillae fading out
gradually on the last two chambers.

DIMENSIONS OF HOLOTYPE.

Maximum diameter =. 0°50 mm.
Minimum diameter == .0O'40 mam.
Thickness =| 0*20imm:

MAIN VARIATION.
1. Chambers 18-22, arranged in 3-3} whorls, generally dextrally coiled.
2. The last whorl is composed of 6-7 chambers.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 131

3. In some specimens the partly developed secondary keel is completely reduced
leading to forms with a single keel throughout the last whorl.

REMARKS. Globotruncana sharawnaensis is unique among the known Globotrun-
cana species, inasmuch as it shows a single keel on the early part of the last whorl and
a double keel on the last one or two chambers. The tendency to reduce the ventral
keel in double-keeled globotruncanas was clearly observed in various species which
normally show a double keel in the early part of the test and become single keeled
later (i.e. reduction by palingenesis). However, no species has yet been recorded as
having a single keel in the early stage and a double keel later, although reduction of
the ventral keel by proterogenesis would produce such forms.

Forms of G. sharawnaensis, with an entirely single keel appear to be somewhat
similar to G. conica White. However, G. shavawnaensis is distinguished from
G. comica by its slightly smaller test, less conical dorsal side and slightly more
protruding ventral one, its somewhat rough ventral side, partially developed
ventral keel and acute axial periphery. It differs from G. orientalis sp. nov. in its
depressed ventral sutures, the character of its keels and the slightly rougher surface
on the ventral side. Globotruncana esnehensis Nakkady & Osman is distinguished
from G. sharawnaensis sp. nov. by its dome-shaped test, less protuding and more
undulating ventral side, more inflated chambers on the dorsal side, wider umbilicus,
smoother surface, and entirely single keel.

Very little is known about the evolutionary history of G. sharawnaensis sp. nov.
However, it may have evolved from G.-avca (Cushman) into G. conica White and/or
G. esnehensis Nakkady & Osman, although no direct evidence was recorded.

HoLotyPe. P.45553.
PARATYPES. P.45554.

HORIZON AND LOCALITY. Holo- and paratypes, from sample No. 20, W.
E]-Sharawna section.

STRATIGRAPHICAL RANGE. Globotruncana sharawnaensis sp. nov. is common in
the Middle Maestrichtian G. gansseri Zone of the studied sections, and dies out com-
pletely in the basal part of the overlying G. esnehensis Zone.

Globotruncana stuarti parva Gandolfi
(Pl. 9, figs. 2a—d)

1951 Globotruncana stuarti (de Lapparent) ; Bolli: 196, pl. 34, figs. 10-12.

1951 Globotvuncana stuart: (de Lapparent) ; Tilev (pars) ; 34-41, text-figs. 8a—d non 7a~d,
non ga—d. (See also Tilev 1952 where figures are repeated.)

1955 Globotvuncana stuarti parva Gandolfi : 65, pl. 5, figs. 7a-c.

1956 Globotruncana aegyptiaca Nakkady ; Said & Kenawy : 150, pl. 5, figs. 19a~-c.

DescripTIon. Test small, subcircular, unequally biconvex, dorsal side very
slightly raised or nearly flat with a slightly raised part in the centre from which the
surface gently slopes radially towards the periphery ; ventral side strongly pro-

132 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

truding ; periphery subcircular in outline, nearly continuous, transversely acute,
with a single well-developed beaded keel ; chambers on the dorsal side 20, arranged
in 4 dextrally-coiled whorls ; the initial chambers are very small, slightly inflated,
globigerine, and are followed by nearly crescentic chambers which increase very
slowly in size till near the beginning of the last whorl where they enlarge very rapidly ;
the last whorl is composed of 4, large, angular conical chambers which are narrow and
strongly elongated in the direction of coiling ; the first one is typically crescentic on
the dorsal side, while the last 3 are roughly trapezoidal ; on the ventral side the
chambers are 44, typically quadrangular with blunt corners and roughly parallel
curved sides ; they are strongly overlapping, distinctly outlined, and strongly
inflated especially around the umbilicus, with the surface somewhat steeply sloping
towards the thinned-out periphery ; sutures on the dorsal side very slightly curved
or nearly straight, angular, limbate, raised and heavily beaded ; on the ventral side
they are strongly curved forward, limbate, raised and heavily beaded ; umbilicus,
narrow, roughly pentagonal in outline, relatively deep, surrounded by thickened,
raised, beaded ridges, and covered by complex tegilla of which remnants are still
preserved ; primary apertures interiomarginal, umbilical, tegilla with accessory
apertures only poorly preserved ; wall calcareous, perforate, except for the imperfo-
rate keel and tegilla ; surface smooth and finely porous.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter =) 70-40 mimi.
Minimum diameter = 0°36 mm.
Thickness =) O:20emm-

MAIN VARIATION.

1. Chambers on the dorsal side 15-20 arranged in 3—4 whorls, usually dextrally
coiled (of 75 specimens picked at random, 2 coiled sinistrally).

2. Chambers in the last whorl 4-5, the first one or two usually crescentic, the last
three trapezoidal and much bigger.

3. The surface is generally smooth but in some specimens small scattered papillae
cover the surface of the initial chambers.

REMARKS. Globotruncana stuarti parva Gandolfi has always been confused with
G. stuartt stuarti (de Lapparent), from which it is believed to have evolved. How-
ever, it can be clearly distinguished by its much smaller size, fewer chambers in the
last whorl, its nearly straight sutures on the dorsal side, its strongly protruding
umbilical side, and by the fact that the last whorl is always much larger than the rest
of the test.

HypotyPe. P.45555.

HORIZON AND LOCALITY. Figured specimen from sample No. 23, W. EI-
Sharawna section.

STRATIGRAPHICAL RANGE. Globotruncana stuarti parva Gandolfi is recorded
from the lower part of the G. gansseri Zone of the studied sections, where it is found

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 133

in great abundance in association with G. stwarti stuarti, G. stuarti stuartiformis and
G. stuarti subspinosa. A few meters higher in the succession, all the other subspecies
disappear, but G. stwarti parva continues as a common to rare form in the overlying
G. esnehensis Zone.

Gandolfi (1955) described G. stuarti parva from the Colon shale of northeastern
Colombia, and considered its range as Campanian—Maestrichtian. However, the
distribution of Globotruncana species in the Colon shale seems to indicate that the
whole formation is Maestrichtian in age as not a single exclusively Upper Campanian
species is present even in the lowest part.

G. stuarti parva was also recorded from the Maestrichtian rocks of Trinidad
(Bolli 1951) and of southeastern Turkey (Tilev 1951, 1952) where it was lumped
with G. stuarti stuartt.

Globotruncana stuarti stuarti (de Lapparent)
(Pl. 8, figs. 4a—-d ; Pl. 9, figs. 1a—d)

1918b Rosalina stuarti de Lapparent : 11~-14, pl. 1, figs. 5, 6, 7, text-figs. 4, 5.

1928 Globotrvuncana rosetta (Carsey) ; White : 286, pl. 39, figs. 1a—c.

1941 Globotyuncana stuarti (de Lapparent) Vogler : 289, pl. 23, figs. 40-43.

1941 Globotruncana linnei stuarti Vogler (pars) : 289, pl. 24, fig. 8, non figs. 9-13.

1945 Globotyvuncana stuart: (de Lapparent) ; Bolli: 236, pl. 9, fig. 18, text-fig. 1 (27, 28).

1948 Globotrvuncana stuarvti (de Lapparent) ; Cita : 160-161, pl. 4, figs. 7a~-c.

1949 Globotruncana (Globotvuncana) stuarti (de Lapparent) ; Reichel: 613-615, pl. 16,
fig. 10, pl. 17, fig. 10, text-fig. 7a.

1951a Globotruncana avca (Cushman) ; Nakkady (pars) : 56-57, pl. 1, fig. 4A, non B-E.

1951 Globotrvuncana (Globotruncana) stuarti (de Lapparent) ; Noth: 78, pl. 8, figs. 12a-c.

1951 Globotruncana (Globotruncana) rosetta (Carsey) ; Noth: 78, pl. 8, figs. 13a-c.

1951 Globotruncana stuarti (de Lapparent); Tilev (pars) : 34-41, pl. 1, fig. 3, text-figs. 7a—d,
non figs. 8a—d, ga—d (see also Tilev 1952 where figures are repeated).

1952 Globotrvuncana stuarti (de Lapparent) ; Sigal: 40, text-fig. 42.

1955 Globotruncana (Globotyvuncana) stuavti (de Lapparent) ; Dalbiez: 163-164, Chart 2,
text-figs. 4a—c.

1955 Globotrvuncana stuarti stuarti (de Lapparent), Gandolfi : 64-65, pl. 5, figs. 6a—c.

1956 Globotruncana stuarti (de Lapparent) ; Knipscheer: 52, pl. 4, figs. 19a—20c, text-figs.
Paey

1962 Globotrvuncana (Globotruncana) stuart: stuarti (de Lapparent) ; Pessagno : pl. 2, figs. 1-3.

“wv

EMENDED DIAGNOSIS. A Globotruncana with large, circular, biconvex test ;
strongly protruding ventral side, and slightly conical dorsal one ; non-lobate entire
periphery, axially strongly acute ; thinned-out, continuous, entirely single keel ;
large number of chambers (18-28) increasing constantly and regularly in size
and strongly elongated in direction of coiling ; large number of whorls (3-4) and
large number of chambers in last whorl (6-7) ; shape of last chambers on dorsal side
roughly trapezoidal ; strongly overlapping quadrangular chambers on ventral side ;
short, slightly curved, raised beaded sutures on both sides.

DESCRIPTION. (Specimen, Pl. 8, figs 4a-d.) Test large, very nearly circular,
lenticular, nearly equally biconvex ; dorsal side slightly raised, very broadly and
gently conical ; ventral side convex, moderately protruding ; equatorial periphery

134 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

circular, non-lobate, almost entire, with a single, well-developed, beaded keel which
slightly weakens on the last chambers ; axial periphery strongly acute ; chambers on
the dorsal side 21 arranged in 34 dextrally coiled whorls ; the initial chambers are
small, inflated, globigerine and are followed by crescentic chambers which increase
slowly and regularly in size as added ; the last whorl is composed of 6, narrow
chambers which increase slowly in size, and are strongly elongated in the direction
of coiling ; the first two are nearly crescentic, the last four roughly trapezoidal ; on the
ventral side the chambers are 6, typically quadrangular with blunt corners and
roughly parallel curved sides ; they are strongly overlapping, distinctly outlined and
strongly inflated with the sides gently sloping towards the marginal keel ; sutures on
the dorsal side short, slightly curved, raised and delicately beaded ; on the ventral
side the sutures are slightly raised and beaded, slightly curved, tending to be nearly
straight, except when they curve strongly around the umbilicus to form the umbilical
flange ; umbilicus medium sized, hexagonal in outline, relatively deep, surrounded by
thickened, raised, beaded ridges, and covered by complex tegilla of which remnants
are still preserved ; primary apertures interiomarginal, umbilical ; tegilla with acces-
sory apertures only poorly preserved ; wall calcareous, perforate, except for the
imperforate keel and tegilla ; surface smooth, with a few small papillae scattered on
the ventral side.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter == OF 530iam,
Minimum diameter = 0-48 mm.
Thickness = 0-26 %mm:

MAIN VARIATION.

1. The dorsal side is very slightly raised to moderately conical, while the ventral
side is always moderately to strongly protruding.

2. Chambers, 18-28, arranged in 34—4 whorls, generally dextrally coiled.

3. Chambers in the last whorl 6-7, but 54 and 8 chambers occur as two extremes.

REMARKS. Globotruncana stuarti stuart was first described by de Lapparent (1918)
as Rosalina stuartt nov. sp. Arni (1933), quite justifiably, removed this species to
the genus Globotruncana, although his G. ? stwarti is different from the holotype and
paratypes of de Lapparent.

Recently, G. stwarti (de Lapparent) was found to include four distinct subspecies
which are :

G. stuart stuarti (de Lapparent) 1918.
G. stuarti parva Gandolfi 1955.

G. stuarti stuartiformis Dalbiez 1955.
G. stuarti subspinosa Pessagno 1960.

The lumping of these subspecies and their transitional forms under G. stuarti
(de Lapparent), and the confusion between this species and various others, led to
disagreement about the diagnostic features and the stratigraphical range of G.
stuartt stuart.

Tilev (1952 : 39-41) considered G. rosetta (Carsey) to be a variety of G. stuart (de

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 135

Lapparent) as he found them together at the same stratigraphical level and they
looked the same in thin sections.

Dalbiez (1955 : 163-164) included G. stwarti (de Lapparent) with G. elevata
(Brotzen) and G. rosetta (Carsey) in one group, depending on the fact that they are all
umbilico-convex and entirely single keeled. However, G. rosetta (Carsey) proved to
have two closely-spaced keels on the early chambers of the last whorl, joining to
form a single keel on the last two chambers. On the other hand, G. elevata has a
distinctly lobate periphery and typically petalliform chambers as opposed to the
entire non-lobate periphery and trapezoidal chambers of G. stuarti. With this in
mind, Dalbiez (1955 : 169) described G. elevata stuartiformis as a new subspecies.
However, this form is actually more closely related to G. stuarti, hence Pessagno
(1960) quite justifiably, changed its name to G. stuarti stuartiformis Dalbiez. On
the other hand, Pessagno (1960 : Ior ; 1962 : 362) considered G. elevata (Brotzen) to
be a subspecies of G. stwarti and changed its name to G. stuarti elevata (Brotzen).
However, the morphological characteristics and stratigraphical ranges of these
two species strongly favour treating them as two distinct species.

Dalbiez (1955 : 164) suggested that G. stuarti stuarti (de Lapparent) had evolved
from G. stuarti stuartiformis Dalbiez during Upper Campanian time by the develop-
ment of a biconvex test and by the change of the triangular chambers on the dorsal
side into the characteristic trapezoidal form. He also added that the whole group
elevata—rosetta—stuarti had probably originated from G. sigali Reichel of the
Lower Turonian, although he had no direct evidence. However, it now seems
more logical to suggest that G. stwarti stuarti evolved from G. stuarti subspinosa in
Upper Campanian—Early Maestrichtian time by the development of a more regular
test, with a circular, entire periphery and narrow chambers which are strongly
elongated in the direction of coiling. On the other hand, G. stuart stuarti is believed
to have evolved into G. stuartt parva during Lower—Middle Maestrichtian time by the
development of a smaller test with fewer chambers in the last whorl, which increase
more rapidly in size. These suggestions conform well with the morphological
development and stratigraphical ranges of these subspecies, and are substantiated by
a whole series of transitional stages between them (see PI. 9, figs. ra—d ; Pl. 10, figs.
1a—d).

Nakkady (19514, pl. 1, fig. 4A) included in Globotruncana arca, typical G. stuarti
stuarty (de Lapparent), as examination of his specimens (B.M.N.H., P.41779) has
revealed.

Bolli (1951) described as G. stwarti (de Lapparent) a form which is typical of
G. stuarti parva Gandolfi, while Papp & Kiipper (1953) described as G. stwarti a form
which most probably belongs to G. elevata (Brotzen).

Gandolfi (1955) described as G. stwarti stuarti (de Lapparent) a form which appears
to be transitional between G. stuarti subspinosa Pessagno and typical G. stuarti stuarti.
Such forms were also recorded from the Esna-—Idfu region, e.g. Pl. 10, figs. 1a—d.
Gandolfi also considered G. conica White as a subspecies of G. stwarti (de Lapparent)
and changed its name to G. stuarti conica (White). However, Gandolfi’s form is

136 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

different from the holotype of White and is not related to G. stwarti (de Lapparent) ;
it needs to be renamed and redescribed in more detail.

Hofker (1956) : 322-324) described as Marginotruncana stuarti (de Lapparent)
a form which is entirely different from Globotruncana stuarti as described and figured
by de Lapparent. He considered the holotype of G. stwarti (de Lapparent) as a
Marginotruncana (a junior synonym of Globotruwncana Cushman as mentioned above),
and tried to distinguish between Marginotruncana stuarti (de Lapparent) and
Globotruncana stuarti of authors, stating that the form belonging to the genus
Globotruncana (in his sense) should not be called stwartiz. He also added, without
any obvious reason, that the European specimens are Marginotruncana stuarti
(de Lapparent), while those from Palestine, Egypt, Trinidad and Texas belong to
a different genus (in his own sense, meaning the genus Globotruncana). However,
as can be seen from his figures, Hofker’s Marginotruncana stuart is probably G.
esnehensis Nakkady & Osman.

HypotyPes. P.45556-57.

HoRIZON AND LOCALITy. Figured specimens Pl. 8, figs 4a-d, Pl. 9, figs. 1a-d,
from Sample No. 18, W. El-Sharawna section ; Pl. 10, figs. 1a—c, which is a tran-
sitional form between G. stuarti subspinosa Pessagno and G. stuarti stuarti (de
Lapparent), is from Sample No. 16 of the same section.

STRATIGRAPHICAL RANGE. G. stuarti stuarti was first described by de Lapparent
(1918) from the Maestrichtian rocks of the Hendaye region, southwestern France,
and was recorded from the same region by Reichel (1950). All later reliable
records are from rocks of Upper Campanian—Maestrichtian age.

In the Esna—Idfu region, G. stuarti stwarti (de Lapparent) occurs as a common
form in the Lower Maestrichtian G. fornicata Zone and continues up to the lower part
of the G. gansseri Zone, where it is abundant, together with G. stuarti parva, G.
stuart stuartifornis, and G. stuarti subspinosa. Only G. stuartt parva continues to
the Upper Maestrichtian, the other three subspecies having died out completely.
This may suggest that records of G. stuarti stuarti (de Lapparent) from the Upper
Maestrichtian are probably erroneous. However, Berggren (1962) stated that
“ valid references to this species indicate its occurrence in the Upper Maestrichtian . ”’
and added “ In Scandinavia G. stuarti s.s. appears for the first time in the Pseudo-
textularia elegans zone (= Praeglobotruncana mayaroensis zone’’, but, Berggren’s
G. stuarti (pl. 10, figs 2a—-c), is not G. stuarti (de Lapparent), neither is Reyment’s
(1960) G. cf. stwarti, nor Witwicka’s (1958) G. stwartt, which he used as evidence.
Again, G. stuarti of Bolli (1951) is actually G. stuarti parva, and that of Pessagno (1962)
is transitional between G. stuart: stuarti and G. stuart parva.

Globotruncana stuarti stuartiformis Dalbiez
(Pl. 9, figs. 3a—d)
? 1937a Globotruncana stuarvti (de Lapparent) ; Glaessner : 39, pl. 1, figs. 13a-c.

? 1953 Globotruncana rosetta (Carsey) ; Hagn : 98, pl. 8, figs. 16a—c, text-figs. 24, 25.
1953 Globotruncana stuarti (de Lapparent) ; Subbotina : 201, pl. 15, figs. 3a—5c.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 137

1955 Globotyuncana (Globotruncana) elevata stuartiformis Dalbiez : 169, text-figs. 1oa—c.

1956 Globotruncana elevata stuartifoymis Dalbiez ; Knipscheer (pars) : 52, pl. 4, figs. 4a, b,
? 12a-c ; non figs. ga—10b, 14a—15b.

1960 Globotyuncana (Globotruncana) stuarti stuarvtifovmis Dalbiez ; Pessagno: trot, pl. 5,
HS) 7, Li.

? 1960 Globotruncana stuarti (de Lapparent) ; Vinogradov, 315, pl. 6, figs. 29a—30¢.

1962 Globotruncana (Globotruncana) stuarti stuartiformis Dalbiez ; Pessagno: 362, pl. 2,

figs. 4-6.

EMENDED DIAGNOsIS. A single keeled Globotruncana with last-formed chambers
triangular in shape, moderately lobate periphery, typically straight, raised sutures
tangential to preceding whorl on dorsal side, roughly wedge-shaped appearance in
side view ; typical stuarti-form chambers on ventral side, and relatively small
umbilicus surrounded by raised, thick, beaded ridges.

DEscRIPTION. Test medium-sized, almost planoconvex, coiled in a very low
trochospire; dorsal side very slightly convex to nearly flat, gently sloping towards
the periphery ; ventral side strongly protruding especially in the later part as the
convexity of the ventral side increases gradually towards the last chamber ; equatori-
al periphery nearly ovoid, moderately lobate ; axial periphery acute, with a single,
well-developed, beaded keel ; chambers on the dorsal side 15, arranged in 24 dextrally
coiled whorls ; the initial chambers are small, slightly inflated, globigerine, and are
followed by crescentic chambers towards the end of the second whorl ; the last whorl
is composed of 5 large chambers, the first two of which are nearly crescentic, while
the last three are typically triangular ; on the ventral side the chambers are 5,
large, stuarti-form with the sutures more strongly curved forward, thus becoming
nearly ovoid, strongly overlapping, distinctly outlined and strongly inflated, with
the surface somewhat steeply sloping towards the periphery, especially in the last
chambers ; sutures on the dorsal side slightly curved in the early part, nearly
straight and tangential to the preceding whorl in the last part, limbate, raised and
beaded, with the beading fading out gradually towards the last whorl ; on the
ventral side the sutures are strongly curved forward, limbate, raised and faintly
beaded ; umbilicus relatively small, roughly hexagonal in outline, moderately deep,
surrounded by much thickened, strongly raised, faintly beaded ridges, and covered
by complex tegilla of which remnants are still preserved ; primary apertures interio-
marginal, umbilical ; tegilla with accessory apertures only poorly preserved ; wall
calcareous, perforate, except for the imperforate keel and tegilla ; surface smooth.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter = ©- 5 tan,
Minimum diameter = © 30 Tam,
Thickness == 0-26) mm.

VARIATION. Dalbiez in his original description of G. stwarti stuartiformis mention-
ed a wide range of variation for this subspecies. In the Esna—Idfu region, as we
have only the uppermost stages of development of this subspecies, the range of
variation is much more limited, and is as follows :

138 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

1. Chambers on the dorsal side, 15 to 18, arranged in three dextrally coiled
whorls (all the studied specimens coiled dextrally).

2. Chambers in the last whorl, 5-6, compared with 5~9 in the specimens studied
by Dalbiez.

REMARKS. Dalbiez (1955 : 169) described G. stwarti stuartiformis as a subspecies
of G. elevata (Brotzen) and named it G. elevata stuartiformis. He considered G.
stuartt of Papp & Kipper (1953 : 39, pl. 2, figs. 2a-c), which appears to be G.
elevata (Brotzen), as synonymous with the present subspecies. Both Dalbiez and
Berggren (1962) considered the single keeled form, wrongly described as G. arca by
Cushman (1946 ; pl. 62, figs. 5a—c), as belonging to this subspecies although it lacks
the characteristic triangular last chambers and the straight angular sutures on the
dorsal side. However, Dalbiez’s subspecies is actually more closely related to the
G. stuarti group than to G. elevata Brotzen as it differs from the latter in the form of
the test, the shape of the chambers both on the dorsal and the ventral sides, and in
the form of the sutures on both sides.

Pessagno (1960 : 101) followed by Berggren (1962 : 62, 63), realizing this, made
G. elevata stuartifornus Dalbiez a subspecies of G. stwarti (de Lapparent) and changed
its name to G. stuarti stuartiformis Dalbiez. These authors then went to the other
extreme and considered G. elevata (Brotzen) as another subspecies of G. stuarti
(de Lapparent) and changed its name to G. stuarti elevata (Brotzen). However,
although Glaessner (1937 : 39) considered G. elevata (Brotzen) as synonymous with
G. stuarti (de Lapparent), and Papp & Kipper (1953 : 39, pl. 2, figs. 2a—c) apparently
misidentified G. elevata for G. stuarti, it has to be mentioned here that G. elevata
is both morphologically and stratigraphically different from G. stwarvti and thus
should be kept separate and should retain its original name, G. elevata (Brotzen).

Dalbiez (1955 : 164) suggested that G. stuart: stuartifornis had evolved into
G. stuarti stuarti (de Lapparent) during Upper Campanian time by the development
of a biconvex test and by the change of the triangular chambers on the dorsal side
into the characteristic trapezoidal form. However, it seems more probable that
G. stuarti stuartiformis has evolved into G. stuarti subspinosa during Campanian time
and that the latter, in its turn, evolved into G. stwarti stuarti. The stratigraphical
ranges and the diagnostic features of each of these subspecies support this proposition.

Specimens of G. stwarti stuartiformis (Dalbiez) from the Esna—Idfu region conform
well with the holotype of Dalbiez and with topotypes kindly forwarded by him to the
present author, although they are slightly smaller.

HypotyPe. P.45558.

HORIZON AND LOCALITY. Figured specimen, from sample No. 18, W. EI-
Sharawna section.

STRATIGRAPHICAL RANGE. Dalbiez (1955: 167, 169, chart 2) recorded the
approximate range of G. stuarti stuartiformis in northeastern Tunisia as Campanian—
Lower Maestrichtian, and added that “‘ many specimens identified as G. stuart: from
the Upper Santonian and Campanian undoubtedly belong to the present subspecies ”’.

Subbotina (1953 : 201, pl. 15, figs. 3a—5c) described as G. stuarti de (Lapparent)

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 139

s.l. from the Campanian—Maestrichtian of the northwestern Caucasus, forms which
are probably G. stwarti stuartiformis Dalbiez as can be seen from her figures.
Because she lumped together the various subspecies of G. stwarti under G. stuarti s.1.
she stated that G. stwarti is a characteristic Senonian species and occurs in the Cam-
panian and Maestrichtian of the northwestern Caucasus and various other places in
the Soviet Union. She also mentioned that Agalarova (1949) had recorded G.
stuarti in the Santonian and the Lower Campanian of Azerbaydzhan (Kabristan—
Unusdagskaya range). Such forms, most probably belong to G. stuart: stuartiformuis.

Pessagno (1960 : 89, chart I, 91, chart 2 and Io1 ; 1962 : 354 charts I, 2, 355
charts 3, 4, and 362) recorded G. stuarti stuartifornis as ranging from the late San-
tonian to the base of the Middle Maestrichtian (base of the G. ganssevi assemblage
subzone) of Puerto Rico.

In the Esna—Idfu region, G. stuart: stuartiformis Dalbiez occurs as a common
form in the Lower Maestrichtian G. fornicata Zone and continues to the basal part
of the Middle Maestrichtian G. ganssert Zone, where it dies out completely.

Globotruncana stuarti subspinosa (Pessagno)
(Pl. 10, figs. 2a—3c)
1960 Globotyuncana (Globotyvuncana) subspinosa Pessagno : 101, pl. 1, figs. 1-9, pl. 5, fig. 5.
1962 Globotvuncana (Globotruncana) stuarti subspinosa (Pessagno) Pessagno : 362, pl. 2,
figs. 7-9.

? non eos awh undulata Lehmann : 148, pl. 9, figs. 3a—c ; text-figs. 2t, w.

DESCRIPTION. (Specimen, Pl. ro, figs. 3a-c.) Test large, subcircular in outline,
umbilico-convex, coiled in a very low trochospire ; dorsal side slightly raised, ventral
side strongly protruding ; equatorial periphery nearly circular, weakly lobate to
almost entire ; axial periphery strongly acute, with a single, well-developed, pinched-
out, faintly beaded keel ; chambers on the dorsal side 23 arranged in 4 dextrally
coiled whorls ; the initial chambers are very small, slightly inflated, globigerine ;
they increase slowly in size and are followed by crescentic chambers which increase
more rapidly in size ; the last whorl is composed of 54 large chambers, the early ones
of which are crescentic, elongated in the direction of coiling and slightly crenulate,
while the last three are roughly trapezoidal and relatively much bigger ; on the
ventral side the chambers are 54, large, overlapping, typically stuarti-form, distinctly
outlined, strongly inflated around the umbilicus and somewhat steeply sloping
towards the pinched-out marginal keel ; sutures on the dorsal side distinct, much
thickened and raised, slightly curved and heavily beaded in the early part, straight
and limbate later, giving the chambers their roughly quadrangular shape ; on the
ventral side the sutures are slightly curved, thickened, raised and beaded ; umbilicus
large, roughly hexagonal in outline, relatively deep, surrounded by raised, beaded
ridges and covered by complex tegilla of which remnants are still preserved ;
primary apertures interiomarginal, umbilical ; tegilla with accessory apertures only
poorly preserved ; wall calcareous, perforate, except for the imperforate keel and
tegilla ; surface generally smooth, with a few small papillae on the early part of the
ventral side.

140 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter = 0:62am.
Minimum diameter = 0°52 mm.
Thickness == 023i nim:

MAIN VARIATION.

1. Chambers, 18-24, arranged in 3-4 whorls, generally dextrally coiled (all the
specimens studied coiled dextrally).

2. The last whorl is composed of 5~7 large chambers which tend to be roughly
trapezoidal in the last part.

REMARKS. Pessagno (1960) described G. subspinosa as a. new species, but in
1962, he regarded it as a subspecies of G. stwarti (de Lapparent). Lehmann (1963)
described as G. undulata n.sp. from the Santonian of the Tarfaya province, western
Morocco, a form which only differs from G. stuarti subspinosa in being raised on the
dorsal side. This form is doubtfully included in the synonymy of G. stuarti sub-
spinosa as it was recorded from slightly older strata.

Globotruncana stuarti subspinosa is distinguished from G. stuart: stuartiformis by the
trapezoidal shape of its chambers on the dorsal side, and from G. stwarti stuarti by its
irregular, slightly lobate periphery, the strongly angular shape of its chambers on the
dorsal side which are much wider and less elongated in the direction of coiling, and
by the less regular rate of growth of its chambers. It is believed to have arisen from
G. stuarti stuartiformis in the early Campanian and to have evolved into G. stuarti
stuartt (de Lapparent) in the Upper Campanian or Lower Maestrichtian. The
stratigraphical ranges of these three forms favour this proposition.

HypotyPes. P.45559.

HORIZON AND LOCALITY. Figured specimens from sample No. 18, W. El-
Sharawna section.

STRATIGRAPHICAL RANGE. G. stuarti subspinosa was first described from the
Parguera limestone and Rio Yauco mudstone formations of Puerto Rico and was
shown on Passagno’s distribution chart (1960 : 89, chart 1) to be rare in his Lower
Campanian Praeglobotruncana gautierensis Subzone, common in his Upper Campanian
Rugoglobigerina vrugosa—Globotruncana rosetta Subzone and in his lowermost
Maestrichtian Globotruncana lapparenti lapparenti Zonule. In 1962 (354-355,
charts 1, 2 and 4) he listed G. stuwartt subspinosa as rare to common in the early
Campanian and rare to abundant in the early Maestrichtian.

In the Esna—Idfu region, G. stuarti subspinosa is rare to common in the Lower
Maestrichtian G. fornicata Zone and continues up to the basal part of the Middle
Maestrichtian G. gansservi Zone, where it dies out completely.

Globotruncana subcircumnodifer Gandolfi

1955 Globotruncana (Rugoglobigerina) civcumnodifer subciycumnodifer Gandolfi: 44, pl. 2,
figs. 8a—c.
21955 Globotvuncana (Rugoglobigerina) pennyi subpennyi Gandolfi : 73, pl. 7, figs. 7a-c.

——E

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT T41

1956 Rugotruncana tilevi Bronnimann & Brown : 547, pl. 22, figs. 1-3.
1956 Rugotruncana ellisi Bronnimann & Brown : 547, pl. 22, figs. 7-9.
1960 Globotvuncana (Rugotruncana) tilevi (Bronnimann & Brown) ; Pessagno: 102, pl. 5,
fig. ro.
1962 Globotruncana (Rugotruncana) subcirvcumnodifer (Gandolfi) Berggren : 67-69, pl. Io,
figs. 4a—c.
REMARKS. Gandolfi (1955) considered Globigerina circumnodifer Finlay to belong
to Rugoglobigerina which he regarded as a subgenus of Globotruncana Cushman, and
described the present form as a new subspecies.

Berggren (1962) stated that examination of the holotypes of G. (R) circumnodifer
Gandolfi, G. (R) penny: subpennyi Gandolfi, R. tilevi Bronnimann & Brown and R.
ellist Bronnimann & Brown proved them all to be junior synonyms of G. (RR) cirvcum-
nodifer subcircumnodifer Gandolfi. He proposed the elevation of this subspecies to
specific rank, naming it Globotruncana (Rugotruncana) subcircumnodifer Gandolfi as
Finlay’s form appears to be a true Rugoglobigerina. However, as Rugotruncana is a
junior synonym of Globotruncana Cushman, as mentioned above, the name of the
species is here considered as G. subcirvcumnodifer Gandolfi.

HypotyPe. P.45560.

HORIZON AND LOCALITY. Hypotype from sample No. 18, W. El-Sharawna
section.

STRATIGRAPHICAL RANGE. Gandolfi (1955) recorded this species from the Colon
shale of northeastern Colombia, where he considered its range as Campanian (in fact
it is most probably Maestrichtian as explained on p. 133).

Bronnimann & Brown described their R. ellisi and R. tilevi, from the Campanian—
Maestrichtian of Texas and Arkansas, and from the Upper Maestrichtian of Habana,
Cuba, respectively.

Globotruncana subcircumnodifer was also recorded from the Lower Maestrichtian
of Puerto Rico (Pessagno 1960), and from the Lower Maestrichtian of Scandinavia
and New Jersey (Berggren 1962).

In the Esna—Idfu region, G. subcircumnodifer is recorded as a common form in the
Middle Maestrichtian G. gansseri Zone, fading out gradually upwards in the section
to occur as a rare scattered form in the Upper Maestrichtian G. esnehensis Zone,
where it dies out completely.

Globotruncana tricarinata colombiana Gandolfi

1955 Globotruncana tricarinata colombiana Gandolfi : 20-22, pl. 1, figs. 3a—-4c ; ? text-figs. 5
(1a—2c), 6 (4a, b).

REMARKS. Globotruncana tricarinata colombiana was first described by Gandolfi
(1955) from the Manaure and Colon shale formations of northeastern Colombia. It
is believed to have evolved from G. tricarinata tricarinata (Quereau) as mentioned by
Gandolfi, who also suggested that it evolved into the form he described as “ G. tri-
carinata colombiana?’’. However, the latter is more closely related to the G. form-

142 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

cata group and may belong to G. fornicata cesarensis Gandolfi. On the other hand,
the morphology and stratigraphical range of G. tricarinata colombiana indicate
that it is possibly related to both G. aegyptiaca aegyptiaca Nakkady and to G.
gagnebint Tilev, which continue in younger strata above.

HypotyPe. P.45561.
HORIZON AND LOCALITY. Hypotype from sample No. 4, Abou Saboun section.

STRATIGRAPHICAL RANGE. Gandolfi (1955) gave the range of this subspecies as
Upper Santonian—Lower Campanian with rare occurrences in the Upper Campanian.

However, as mentioned above, his Campanian may possibly belong to the
Maestrichtian.

In the Esna—Idfu region, G. tvicarinata colombiana is common in the Lower
Maestrichtian G. fornicata Zone; it decreases gradually in number upwards in the
section becoming rare in the lower part of the Middle Maestrichtian G. gansseri Zone,
where it dies out completely.

Globotruncana tricarinata tricarinata (Quereau)
1893 Pulvinulina tricavinata Quereau : 89, pl. 5, figs. 3a—d.
1918 Rosalina linnei type 2 de Lapparent : 4, pl. 1, fig. 1, text-figs. 1b, d—f; 5, 2d, n.
1941 Globotruncana linnei tricarvinata (Quereau) Vogler : 287, pl. 33, figs. 22-31.
1942 Globotruncana linnei (d’Orbigny) ; Gandolfi, pl. ro, fig. 7.
1945 Globotruncana lapparenti tricavinata (Quereau) ; Bolli: 232, pl. 9, fig. 13, text-figs. 1

19, 20).
oe Bale canaliculata (Reuss) ; Cushman (pars): p. 149, pl. 61, figs. 18a—c, non

figs. 17a-c.

1951 Globotvuncana lapparenti tricarinata (Quereau), Tilev : 79-86, text-figs. 24a—-d. (See also

Tilev 1952 where figures are repeated.)

1953 Globotvuncana lapparenti Brotzen ; Subbotina (pars) : 178, pl. 7, figs. 3a-4c ; ? pl. 6,
figs. 5a—6c ; ? pl. 7, figs. 1a—2c, 5a—c.
1960 Globotvuncana lapparenti lapparenti Brotzen, Vinogradov : 313, pl. 2, figs. 8a—c.

REMARKS. Globotruncana tricarinata tricarinata was first described, from thin
sections only, by Quereau (1893). The morphological characters and stratigraphical
distribution of the species were later much confused, and its interpretation by differ-
ent authors varied considerably.

Gandolfi (1955) described G. tvicarinata colombiana as a new subspecies and thus
Quereau’s form is here designated as nominate subspecies.

As can be seen from Quereau’s original description and figures, the species is
mainly characterized by the umbilical flange which is so well developed that in side
view or in thin section, it appears as a third carina beside the two well-developed
marginal keels ; hence its name. However, various forms showing the same charac-
ter, but differing in the shape of test and in the number and shape of chambers were
figured by subsequent authors.

Until isolated specimens from the type section of Quereau are carefully examined,
it is not possible to decide which of these forms is G. tvicarinata tricarinata (Quereau).

The few specimens recorded from the Esna—Idfu region show clearly the two

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 143

well-developed marginal keels and the strongly protruding umbilical flange character-
istic of Quereau’s form. They also conform well with the figures given by Tilev
(1951, 1952) whose thin section is almost identical with that of Quereau. However,
they differ from the forms figured by Cita (1948), Noth (1951), Said & Kenawy (1956)
and Berggren (1962). The form figured by Barr (1962) as G. linneiana tricarinata
(Quereau) may possibly belong to G. tvicarinata colombiana Gandolfi.

Globotruncana tricarinata tricarinata is believed to have evolved from G. linneiana
linneiana (d’Orbigny) into G. avca (Cushman) as previously suggested by various
authors (e.g. Vogler 1941, Gandolfi 1955, Bronnimann & Brown 1956 and Berggren
1962).

HypotypPe. P.45562.
HORIZON AND LOCALITY. Hypotype from sample No. 3, Abou Saboun section.

STRATIGRAPHICAL RANGE. Globotruncana tricarinata tricarinata was first described
from the Campanian—Maestrichtian of Switzerland and was recorded from the same
level in various parts of the world.

In the Esna—Idfu region G. tvicarinata tricarinata is common in the Lower Mae-
strichtian G. fornicata Zone, decreasing gradually upwards in the section to die out
completely before the basal part of the overlying G. gansseri Zone.

Globotruncana ventricosa White

1928b Globotrvuncana canaliculata (Reuss) var. ventricosa White : 284, pl. 38, figs. 5a—c.
? 1954 Globotruncana ventricosa White ; Nakkady & Osman: 90-91, pl. 19, figs. 9a—c.

1955 Globotrvuncana ventricosa cavinata Dalbiez : 171, text-figs. 8a—d.

1957a Globotruncana ventricosa White ; Bolli: 57, pl. 13, figs. 4a-c.

REMARKS. Brotzen (1936) raised White’s variety to specific rank although his
figures are completely different from those of White. The form described by Sigal
(1952) as G. lamellosa, from the Lower Maestrichtian of Algeria, appears from his
figures to be closely related to G. ventricosa White. However, examination of the
type specimens of G. /amellosa Sigal showed that the latter species is distinguished
by its unequally biconvex test, with a more protruding ventral side ; highly lobate
periphery ; two closely spaced keels, reduced to a single keel on the last few chambers
or chamber ; a well developed umbilical flange ; curved, raised, beaded dorsal
sutures and radial, depressed ventral ones ; and its very wide umbilicus.

Dalbiez (1955) described two new subspecies of G. ventricosa White which he
named G. ventricosa carinata and G. ventricosa primitiva respectively, and thus
he changed the name of the present species to G. ventricosa ventricosa White. How-
ever, examination of the type specimens of these forms in Dr. Dalbiez’s collection
showed that his G. ventricosa ventricosa White is actually G. concavata Brotzen, and
that although the figures were published under the first name, the slide carried the
name G. ventricosa concavata (Brotzen). Again, the holotype of G. ventricosa
carinata Dalbiez was found to differ from G. ventricosa White only in having a
slightly wider umbilicus and a more developed umbilical flange. Variation in such

144 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

characters is well known in populations of G. ventricosa White and is not considered
of any taxonomic importance. Thus G. ventricosa carinata Dalbiez is considered a
junior synonym of G. ventricosa White. Similarly, the holotype of G. ventricosa
primitiva Dalbiez, although not well preserved, is identical with G. concavata (Brot-
zen) of which it is here considered a junior synonym.

Globotruncana ventricosa White was also confused with G. gagnebini Tilev (e.g.
Bolli 1951, Gandolfi 1955, etc.) and with G. tvicarinata (Quereau) (e.g. Mornod 1950).
It has possibly evolved from G. tricarinata tricarinata (Quereau) and into G. gagnebin
Tilev, although Gandolfi (1955) suggested its evolution from G. tricarinata colombiana.

HypotyPe. P.45563.

HORIZON AND LOCALITY. Hypotype from sample No. 16, W. El-Shasawna
section.

STRATIGRAPHICAL RANGE. White (1928) described this species from the Campan-
ian, Papagallos shale of Mexico, and Bolli (1957a) restricted its range to his Globo-
truncana stuartt Zone which he considered as Upper Campanian. It was also
recorded from the Campanian—Maestrichtian of southwestern Sinai, Egypt (Nakkady
& Osman 1952) and from the Upper Santonian of Tunisia (Dalbiez 1955).

In the Esna—Idfu region, G. ventricosa is rare in the Lower Maestrichtian G.
fornicata Zone and in the lower part of the Middle Maestrichtian G. ganssert Zone,
where a great number of transitional stages occur between it and G. gagnebimt
(e.g. Pl. 2, figs. 3a—d).

Globotruncana youssefi sp. nov.
(Pl. 6, figs. 4a—d)

DiaGnosis. A Globotruncana with large, subcircular, strongly umbilico-convex
test ; distinctly lobate periphery ; entire single keel; globigerine early part and crescen-
tic later chambers ; strongly curved, raised beaded dorsal sutures ; peculiarly shaped
last chamber slightly tilted towards the umbilicus, surface rough.

DeEscriPTION. Test large, planoconvex, umbilico-convex, coiled in a low trocho-
spire ; dorsal side almost flat and weakly imbricate, with the last chambers slightly
lower than the early ones; ventral side strongly inflated and very distinctly pro-
truding ; equatorial periphery subcircular, distinctly lobate with a single, well-
developed, much thickened and beaded marginal keel ; axial periphery subangular ;
chambers on the dorsal side 19, arranged in 3 dextrally coiled whorls ; the initial
chambers are very small, globular and inflated ; they increase slowly in size, and are
followed by relatively larger, globular, weakly inflated chambers which tend to be
slightly elongated in the direction of coiling ; the last whorl is composed of 54 large,
crescentic chambers which increase slowly in size, except for the last which has a
peculiar angular shape that makes it appear slightly smaller than the penultimate ;
on the ventral side the chambers are 54, large, angular conical, strongly inflated and
distinctly protruding ; sutures on the dorsal side short, radial, depressed in the early
part, distinctly curved, raised and beaded in the later part, although the beading

CRETACEOUS ———_frateovene [_ SVSTEM/SERIES J
SENONIAN | ———— MA ESTRICH TIAN ——— 2) DANIAN STAGE

CAMPANIAN|/LOWER MAESTRICHTIAN [MIDDLE MAESTRICHTIAN |UPPER MAESTRICHTIAN SUBSTAGE

SAT SHARAWNA formation Ta FORMAT ON

Tower Shorawna shale [Mid/ Shor Upper Sharawna) shale

Globotruncana Farnicata zone |Globotruncana gansseri) zone

Lower:
‘Owaina shale

MB
Globotruncana esnehensis zone je cerermmve. | FAUNAL ZONE

1] Globotruncans adamal a. 4p

3|| Globotruncans aegyptlaca acgyptiaca
ey

3] Globotruncana aegyptiaca duwi
NAKKADY

3], Glovotruncana arca
CUSHISAN

ana bahijae n. 9
7] Globotruncana contea
WHITE

8] Globojruncana
CUSHMAN)

na witwickae fy

cf convexa Wy
tb Globotruncana
M4] Globotruncana fareedi n. 4p.
cata fornicata 18

globulecamerata n. subsp

Ayiwsojuoasig

NA

ana. gagoebinl

za] Globotruncana ef, gagnebini

dicarinata

(DE LAPPARENT)

a} Globotru
(QUEREAU)

trlcarinata trie

WHITE a

Fic. 9. Distribution of Globotruncana species in the Maestrichtian Sharawna Shale formation

es iD aad

v
e | [ae Joke vowhindd saan
‘ : ote be
|

+ oie nay lode

LONE

aegyptiaca
duwi

ESNEWENSIS

6 arabica

G.

| DISCONFORMITY a

6. eSnehensis 6. stuart
parva

G cf convexa

ERI ZONE

G_ hovanensis:

GANSSERI

G gansseri ses
subgansseri

ai

+
6. contusa
contusa

(roms, G. contusa
IS patelliformis
7

elei—

| gansseri =
dicarinata--r-» 3
' s
' G.gansseri
i] gansseri 6. ra NE .
1 naive r eel G. fornicate
| | hed ‘ackermanni
5 os ‘i (opicata :
oe S rosetta globulocamerata D
a5 = rosetla — O-sluarlt a 6 odomsi 5
ee = | é
2 = =: 6 contusal
@ 5 Dp witwickoe

6. cegyptioca
aegyptiaca

G._FORNICATA

eliat tr 4 =
subspinosa 24

Cesorens!s
SI

Gistuartie Grconlbea
stuart iformis sculilla mrongurens

han cata

Fic. 10.

Suggested Phylogeny of the Globotruncana species in the Maestrichtian Sharawna Shale of the Esna-Idfu Region.

-— ee >

a _ oo ~ bosch

» : =

ta pe Thy
|
s
“
IVP) ©

ik ym “<a Re

tae.

We 7 ®
~~ a2, ou _ C ed 7 o
i _ a u
We ca a . en ae on Pape é —— : a — 7 J.
»
— i > i
a ee - a —— —— I — =
4 , es, Se « =

jonyy Jo wor! “TL OWT

*uORRULOS a[eYS BUMEIEYS uNAYyoHy:

(latoaxva)
wapioyeyed FTT9940qP 9H i

(nosso)
ayguayynowuoU e]93s0AIH q

(onovssad)
ru, OSOIPIH, ler

(onovssaa)
Jewoy ywxay ETON z0qpOR, et

(onoyssaa)
sywaoy}ss92dwo> eRay eT|a30qP9H “

yilsousaqaH sana

(11108)
syeusosetem snpeqswomedy

(11108)

ejpomsaqu) snpeyiwomeqy

S0IVaaWOnLVay SANaD

NNVAINNOWE.
Wo2# ETAL .

Virani sano)

mity

(uayoxnna)
soins ou s08]qo1203n

Disconfor

ANVIINNOWG.
enepanyos ex] za |qoTsoRNy

NNVIINNOUE.
marynaend ex} 303\ 07303 5

NNYINNOUG
VKauad ex] 39% qo1303M

NNYWINKOUG.
wrelazoa9¢u ex] 293\q01203 g

(ssavn)
11207901 eu z93}qoTHOIM P

1aloaKvo
JsouRsoeT3 wan 205 qo 1208 uv

YuruapIg0790990 sana

INOZ WN ae ae auoz, sisuayausa 0U0IUNI}Oq0)9) auoz |4assuOb OuDIUNJ}Oq0)9| auOZ D)OaIUJ0) DUDDUNI\0q0)9|

HaSWaW see mers SINS CUMDIOYS daddy PBDI | a10¥S OUMDIOYS 1@M0]

NOIVWHO4 ita UOT}OWIOY YNMVYVHS mers

I9NVISANS NWILHOTULSIVA BSddN[NVILHOLUISAVA 31001] NVILHOINISAYA Y3MO1| NYINYdWYS

J9VIS NVINVON$S | _ NWIDHS aS ve vino

WIISAS OE | <= SOMO) SSW Eel)

AL
A

od ye

«.

f
MATERA WA LING |

7
POPES D Ae p pO wept

a
VJcabee ti P ea entiation mmr raeed

A ee ee ey gah a tee |e ame

sige fast wiy

- ¥ — whee tte ae

cenls lier R t | Peer bY SYSTEM
PALEOCENE EOCENE SERIES

LOWER PALEOCENE MIDDLE UPPER LOWER Thick
(DANIAN) PALEOCENE PALEQCENE EOCENE
FORMATION

OWAINA formation THEBES formation
LOWER OWAINA SHALE Thebes Calcareous shale |iime- MEMBER

stone
Globorotalia compressa— Globorotalia angulata | Globorotalia velascoensis Clbroretalic Guilleazensts FAUNAL 20 NE
Globigerina doubjergensis zone zone zone

i i ; d dii |G ; '
_ RRR Fe a FAUNAL SUBZONE

1 1] Globigerina aquiensis
Cm a LOEB LICH and TAPPAN

MIDDLE OWAINA
chal k

UPPER OWAINA
Shale

2) Globigerina arabica n. sp.

3 3) Globigerina bacuana
re CHALILOV

4) Globigerina belli
WHITE

5 5} Globigerina chascanona
LOEBLICH and TAPPAN

6) Globigerina daubjergensis
BRONNIMAN

7| Globigerina haynesi n. sp.

@

Globigerina inaequispira { : i
SUBBOTINA

AjiWso;uorsig

9| Globigerina kozlowskii
BROTZEN and POZARYSKA

10

Globigerina mckannai é
WHITE

Globigerina nodosa n. sp.

Globigerina soldadoensis
BRONNIMAN

Globigerina spiralis
BOLLI

Globigerina stonei
WEISS

15°

Globigerina triloculinoides, ie
PLUMMER :

Globigerina velascoensis
CUSHMAN

18|Globigerina alanwoodi n. sp

Fic. 12. Distribution of Globigerina species in the Paleocene—Lower Eocene Owaina and Thebes formations.

SS va Bikes A. oe oo ke b=, iy a G red, -—

—— 2 “eae

ESUBDOATIAT. “<=

a

we te gy fh ome — a te

naety | | 9yg0tm Wayaaa y Nawny :
EC SPLE ae) ME LEP LERLS| ies CHR I, a;
Mo) Anais! A Hi kaw Dp ae s

1 SARe — AM AWO » SEWED

APOioahe i. =a

Co)
eS
oO
—=N
=)
—_— Ww
=
ow
a=
vay
~<
ee
ayes)
=

nsis
zone

G.aequa/ ©
Hesnde
SU

zone

Globorotalia velascoensis

Globorotalig.
pseudomenardi!

CB)
See
==) (2)
x oN
BS
BS oD
> = on
m i=)
= da} (=)
oO CS
On
@
=)
= a
=
S @
=
° Sec
i= = oO
=) oS
= \ss
[) = @
= Ss
(dks) JS) 1S
io =
l=]
(com
oO
S
>
@
(=
=)
N
oS
a2
nn
oc
(sa
=
o wb
—
aS
>
i=}
=
(Sifts)
=
Se
—- ww
(=)
2) 2)
ou
—"' ©
(sy f=)
(&)

=
Sp
on
(s(=
D> ow
pe anf ox
~ VO
OCn
an”
ow
co

Ch =>

>I<— LOWER

me 6.soldadoensis

G. aquiensis - <- -
8
8

ea

--->--6, velascoensis

G. inaequispira

ea ae

Le yee rr te eee Gkozlowskii

---------[->

sieeae

G. belli--- >--G uaa

DISCONFORMITY

MAESTRICHTIAN >(<——— PALEOCENE

a:

ee
a

G. triloculinoide
parva

Fic. 13. Suggested Phylogeny of the Globigerina species in the Paleocene—Lower Eocene Owaina and Thebes formations of the Esna-Idfu Region.

nn

= oe

i

_—=ihoowap

at *

14)

iy
Ria’

or)
bie,

ces i] Sikes he eA OR FY

oY Stem

peo CrCl e NE EOCENE

SERVES

LOWER PALEOCENE MIDOLE UPPER LOWER
( DANIAN } PALEQCENE PALEQICEINE EOCENE

STAGE

sharawna LOWER OQWAINA SHALE eerie | re Thebes Calcareous shale

shale

OWAINA formation | THERES formation

FORMATION
MEMBER

Globorotalia compressa— Globorotalia angulata Globorotalia velascoensis Globorotalia wilcoxensis
Globigerina daubjergensis zone zone zone zone
loborotalia loborotalia |G pseudomenardii |G.aequa-G.esnaensis
uncinata subzone |pusillasubzone subzone sub zone

Ajiwsojyuorsig

10

VW

12

13

16

7

20

21

22

23

24

37

38

39

40

4)

FAUNAL ZONE
FAUNAL SUBZONE

Globorotalia acuta mle
TOULMIN §

Globorotalia aequa
CUSHMAN and RENZ

Globorotalia africana n. sp.

<aerr
Globorotalia angulata abundocamerata
BOLLI

Globorotalia angulata angulata
(WHITE)

Globorotalia apanthesma
LOEBLICH and TAPPAN

Globorotalia berggreni n. sp.
Globorotalia bollii n. sp.

Globorotalia compressa
(PLUMMER)

Globorotalia cf. convexa
SUBBOTINA

Globorotalia ehrenbergi
BOLLI

Globorotalia emilei n. sp. é

Globorotalia esnaensis
(LE ROY)

Globorotalia faragi n. sp.

Globorotalia hispidicidaris
LOEBLICH and TAPPAN

Globorotalia imitata
SUBBOTINA

Globorotalia irrorata
LOEBLICH and TAPPAN

Globorotalia kilabiyaensis

Globorotalia loeblichi n.sp.

Globorotalia nicoli
MARTIN

Globorotalia occlusa
LOEB LICH and TAPPAN

Globorotalia perclara
LOEBLICH and TAPPAN

Globorotalia pseudobulloides
(PLUMMER)

Globorotalia pseudomenardii
BOLLI

Globorotalia pusilla laevigata ©
BOLLI

Globorotalia pusilla mediterranica n. subsp.

Globorotalia pusilla pusilla
BOLLI

Globorotalia quadrata
(WHITE)

Globorotalia sibaiyaensis n. sp. <4

Globorotalia tribulosa
LOEBLICH and TAPPAN

Globorotalia trinidadensis
BOLLI

Globorotalia troelseni
LOEBLICH and TAPPAN

Globorotalia uncinata carinata

Globorotalia uncinata uncinata
(BOLLI)

Globorotalia velascoensis caucasica
GLAESSNER

Globorotalia velascoensis parva
REY

Globorotalia velascoensis velascoensis
(CUSHMAN) :

Globorotalia whitei
WEISS

Globorotalia wilcoxensis
CUSHMAN and PONTON
Globorotalia woodi n. sp.

Globorotalia sp.

Fic. 14. Distribution of Globorotalia species in the Paleocene—Lower Eocene Owaina and Thebes formations.

—_. ee ee ell

Jjahe

a Sik StstS Ts oaeeveee
’
“bios xf

wa) anand ripAram
a es haa

°

q 4 . ’
] . |
A J @
| “9 ee
" ee, za
r oo
ri x. = 4
a y é -~ % as |
"7 rf
he a ORE BP ay + ——-
‘ : } : » |
ect bd
| ' : ; =
{ Pe “i, 1 } j ‘
q - ae : . - j ~* bl
“& * ng — I '
. « et ble a
|.
i ae _ ~
q am |
= > aa lle
~ } - ares
£ J
| |
| |
! , i )
“ /
‘ - >
" ae
“Cana,
a a
* yy
« a =.
——s anit a
*. ‘* ee — ie roe nam
\ -

le |S
S G Wilcorensis
=
S
6 (roelseni

G. hispidicidaris

G aequa /G esnoensis subzche

G.nicoli a”
ison <= i !
i | as | i }

ee

G.bergareni

Globorotalia yelascoensis Zone

G pusilla
mediterranica

0) pseudomenardii subzone

—>

1 5 elie E
G. opanthesmo 6 veloscoensis
pestle | 6. velaseoensisic ey 3)

G. pusilla,
(aevigata}

subzone

6 uncina}o
corinata

t
x 7 ah ibergi
ee G tribuloso
3 6 ongulota

angulata = 6 emiler
G.uncinato >
un cnata ~~ Gtrinidadensis |

‘ongulata Zone
PALEOCENE

Globorotalia
subzone

Uncinata

6

6 faragi Se REO IN ERT eS 3a ea

5 ------«---
$5) G. quadrata 6. imitata “é
Be ‘ 6 AMlobiycensis
se 6. compressa
= Pees = z <6. bulloide
Lt DISCONFORMITY peels

PESTA

Tdfu Region.

Fic. 15. Suggested Phylogeny of the Globorotalia species in the Paleocene-Lower Eocene Owaina and Thebes formations of the Esn

Correction: G. pusilla laevigata arose from G. pusilla pusilla and ranges throughout the lower part of the G. velascoensis Zone only.

UeMOGM

j

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 145

fades towards the inner whorl ; on the ventral side the sutures are straight,
radial and strongly depressed ; umbilicus pentagonal in outline, wide, deep and
covered by complex tegilla of which remnants are still preserved ; primary apertures
interiomarginal, umbilical ; tegilla with accessory apertures, only poorly preserved ;
wall calcareous, perforate except for the imperforate keel and tegilla ; surface rough
in the early part, heavily papillose or even nodose with the papillae decreasing
gradually towards the last chamber.

DIMENSIONS OF HOLOTYPE.

Maximum diameter =| 0°54 mm,
Minimum diameter = 0°43 10m,
Thickness = 0:31 mm. (of last chamber)

MAIN VARIATION.
1. Chambers 11-21, arranged in 2~—3 whorls which are generally dextrally coiled.
2. Chambers in the last whorl 4-6, most commonly 5.

REMARKS. Globotruncana youssefi sp. noy. is morphologically similar to both G.
lugeom var. angulata Tilev and G. arabica sp. nov. It is distinguished from the
former by its typically crescentic chambers throughout, peculiarly shaped last
chamber, strongly curved, raised, beaded dorsal sutures and more strongly developed
marginal keel. It differs from G. arabica by its almost flat to slightly raised dorsal
side, its longer, more curved, raised and beaded dorsal sutures and its perfectly
marginal keel.

This species is named after Professor M. I. Youssef, of the Department of Geology,
Ain Shams University, Cairo.

HoLotyPe. P.45564.
PARATYPES. P.45565.

HorIzoN AND LOCALITY. Holo- and paratypes, from sample No. 16, Gebel
Owaina section.

STRATIGRAPHICAL RANGE. Globotruncana youssefi sp. nov. appears in the upper
part of the Middle Maestrichticn G. gansseri Zone. It increases upwards in the
section to flood the uppermost part of this zone and the lower part of the overlying
G. esnehensis Zone where it dies out completely.

Globotruncana sp.
(Pl. 1, figs, 6a—c)

DESCRIPTION. Test large, weakly biconvex, coiled in a slightly high trochospire ;
dorsal side broadly arched, ventral side slightly inflated ; equatorial periphery
subcircular, distinctly lobate, with two well-developed, beaded keels reduced to one
on the last chamber ; axial periphery truncate ; chambers on the dorsal side 21,
arranged in 3 dextrally coiled whorls ; they increase slowly and regularly in size ;
initial chambers very small, subglobular, weakly inflated, and followed by subcircular
to crescentic flattened chambers ; the last whorl is composed of 64 large, crescentic to

146 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

petaloid, flattened, or even slightly depressed chambers ; on the ventral side the
chambers are 63, large, subcircular to ovoid, weakly inflated and slightly over-
lapping ; sutures on the dorsal side curved, raised, thickened and heavily beaded ;
on the ventral side they are slightly curved forward, depressed and beaded ; umbilicus
polygonal in outline, relatively wide, deep, surrounded by slightly raised, beaded
ridges and covered by complex tegilla of which remnants are still preserved ;
primary apertures interiomarginal, umbilical ; tegilla with accessory apertures only
poorly preserved ; wall calcareous, perforate, except for the imperforate keels and
tegilla ; surface delicately papillose on the dorsal side, coarsely papillose on the
ventral.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter == O51) mim,
Minimum diameter = 0-44; mim.
Thickness — 1 0-25 mim.

REMARKS. Although the present form is clearly distinguished from the known
Globotruncana species, it was decided not to name it for the time being because of its
rarity. It is morphologically similar to G. avca (Cushman), from which it is dis-
tinguished by its more compressed test, papillose surface, depressed ventral sutures
and single keel on the last chamber. It may have evolved from G. arca (Cushman)
as suggested by their morphological features and stratigraphical distribution,
although no direct evidence was recorded.

MATERIAL. P.455606.

HORIZON AND LOCALITY. Figured specimen from sample No. 20, W. El-Sharawna
section.

STRATIGRAPHICAL RANGE. The present species is rare in the Middle Maestrichtian
G. gansseri Zone.

Genus RUGOGLOBIGERINA Bronnimann 1952
TYPE SPECIES. Globigerina rugosa Plummer 1926.
1952 Rugoglobigeyina Bronnimann : 16 (Type species : Globigerina rugosa Plummer 1926).

1956 Kugleyina Bronnimann & Brown : 557 (Type species : Rugoglobigerina rugosa votundata
Bronnimann 1952).

Rugoglobigerina glaessneri Gandolfi
1955 Globotyuncana (Rugoglobigerina) glaessneri glaessnevi Gandolfi ; 50, pl. 3, figs. 10a—c.

REMARKS. Rugoglobigerina glaessnert is common in both the Middle and Upper
Maestrichtian (G. gansseri and G. esnehensis Zones) of the sections studied. The
species was originally described from the Colon shale of northeastern Colombia which
was regarded by Gandolfi (1955) as of Campanian—Maestrichtian age, but is most
probably of Maestrichtian age only. The form described by Gandolfi as G. (R.)
glaessnert subglaessneri is probably a Globotruncana not a Rugoglobigerina.

HypotypPe. P.45649.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 147

HoRIzON AND LocALITy. Hypotype from sample No. 21, W. El-Sharawna
section.

Rugoglobigerina loetterli (Nauss)

1947 Globigerina loetterli Nauss: 336, pl. 49, figs. 11a—c.
1955 Globotruncana (Rugoglobigerina) loetterli loettevli (Nauss): Gandolfi: 35, pl. 1, figs. 15a—c.
1955 Globotruncana (Rugoglobigerina) loetterli subloetterli Gandolfi: 36, pl. 1, figs. 14a—c.

ReMARKS. A few specimens of R. loetterli (Nauss) have been recorded from the
top part of the Lower Maestrichtian throughout the Middle and Upper Maestrichtian
of the Esna—Idfu region. The species was originally described by Nauss (1947) from
the late Cretaceous Lloydminster shale of Alberta, Canada, and was recorded by
Gandolfi (1955) from the Maestrichtian, Colon shale of northeastern Colombia.
The form described by Gandolfi as G. (R.) loetterli subloetterli is here questionably
included in the present species, which occasionally shows an arrangement of surface
rugosity in the form of weakly developed pseudo-keels.

HypoTyPe. P.45650.

HoRIZON AND LOCALITY. Hypotype from sample No. 16, W. El-Sharawna
section.

Rugoglobigerina macrocephala Bronnimann

1952 Rugoglobigerina (Rugoglobigerina) macrocephala macrocephala Bronnimann : 25, pl. 2,
figs. 1-3, text-figs. ga-—s.

1952 Rugoglobigerina (Rugoglobigerina) macrocephala ornata Bronnimann : 27, pl. 2, figs. 4-6,
text-figs. 10a—1.

1955 Globotruncana (Rugoglobigerina) macrocephala macrocephala (Bronnimann) ; Gandolfi :

45, pl. 2, figs. 12a-c.

1962 Rugoglobigerina macrocephala Bronnimann ; Berggren: 76—78, pl. 12, figs. 4a—-c, text-

figs. 9 (1a—4c), 10 (1-55).

REMARKS. Rugoglobigerina macrocephala floods the Middle and Upper Maestrich-
tian of the sections studied. The species was originally described from the Upper
Maestrichtian of Trinidad (Bronnimann 1952) and was later recorded from the
Maestrichtain of northeastern Colombia (Gandolfi 1955) and of Denmark (Berggren
1962). Rugoglobigerina (R) macrocephala ornata Bronnimann is a junior synonym of
the present species and so is probably G. (R.) ornata ornata (Bronnimann) of Gandolfi
(1955). On the other hand, both G. (R.) macrocephala submacrocephala Gandolfi
1955 and G. (R.) ornata subornata Gandolfi 1955, possibly belong to the genus
Globotruncana, not Rugoglobigerina.

HypotypPe. P.45651.

HoRIZON AND LOCALITY. Hypotype from sample No. 16, W. El-Sharawna
section.

148 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

Rugoglobigerina pennyi Brénnimann
1952 Rugoglobigerina (Rugoglobigerina) rugosa (Plummer) subsp. pennyi Bronnimann: 34-35,
pl. 4, figs. 1-3, text-figs. 14a-1.
1955 Globotruncana (Rugoglobigerina) pennyi pennyi (Broénnimann) ; Gandolfi: 73, pl. 7,
figs. 8a-—c.
1957 Rugoglobigerina rugosa (Plummer) ; Edgell: 115, pl. 4, figs. 10-12.
1962 Rugoglobigerina pennyi Broénnimann ; Berggren: 75, pl. 12, figs. 1a—3c.

Remarks. Rugoglobigerina pennyi is common in the Middle and Upper Maestrich-
tian of the sections studied. The species was originally described from the Upper
Maestrichtian of Trinidad (Brénnimann 1952) and was later recorded from the
Maestrichtian of northeastern Colombia (Gandolfi 1955), of northwestern Australia
(Edgell 1957), and of Scandinavia (Berggren 1962).

HypotyPe. P.45652.

HORIZON AND LOCALITY. Hypotype from sample No. 18, W. El-Sharawna
section.

Rugoglobigerina pustulata Bronnimann

1952 Rugoglobigerina (Rugoglobigerina) veicheli pustulata Bronnimann : 20, pl. 2, figs. 7-9 ;
text-figs. 6a—m, 7a-1.

1960 Rugoglobigerina veicheli pustulata Bronnimann ; Olsson: 50, pl. Io, figs. 13-15.

1962 Rugoglobigerina pustulata Brénnimann ; Berggren : 78-80, pl. 13, figs. ta—c ; text-fig.

10 (6-12).

REMARKS. Rugoglobigerina pustulata is common throughout the Middle and
Upper Maestrichtian of the sections studied. The species was originally described
from the Upper Maestrichtian of Trinidad, and was later recorded from the Mae-
strichtian of New Jersey, U.S.A. (Olsson 1960) and from the Upper Maestrichtian of

Denmark (Berggren 1962).
HypotyPe. P.45653.

HorRIZON AND LOCALITY. Hypotype from sample No. 18, W. El-Sharawna
section.

Rugoglobigerina rotundata Bronnimann

1952 Rugoglobigerina (Rugoglobigerina) yvugosa (Plummer) subsp. votundata Broénnimann : 34,
pl. 4, figs. 7-9 ; text-figs. 15a—16c.

1955 Globotruncana (Rugoglobigerina) votundata votundata (Bronnimann) ; Gandolfi: 7o,
pl. 7, figs. 2a—c.

Remarks. A few specimens of R. rotunda have been recorded from the Upper
Maestrichtian of the sections studied. In the G. Owaina section, rare specimens
were also recorded in the Upper part of the Middle Maestrichtian. The species was
originally described from the Upper Maestrichtian of Trinidad, and was recorded
from the Maestrichtian of northeastern Colombia (Gandolfi 1955) and as R. cf.
votundata from the Upper Maestrichtian of Denmark (Berggren 1962). Bronnimann
& Brown (1956) made the present species the type of their monotypic genus Kugleri-

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 149

na, which was said to differ from Rugoglobigerina in being more highly spired, having
a smaller and deeper umbilicus, and in having short apertural flaps which extend into
the umbilicus, but do not form a cover-plate. However, as the cover-plate is a
delicate structure which is rarely well preserved, and as the other characters are of
specific rather than generic importance, Kuglerina Bronnimann & Brown 1956 is
considered a junior synonym of Rugoglobigerina Bronnimann 1952.

HypotyPe. P.45654.

Horizon AND LocaLity. Hypotype from sample No. 23, W. El-Sharawna
section.

Rugoglobigerina rugosa (Plummer)

1926 Globigerina rugosa Plummer : 38, pl. 2, figs. 1oa—d.
1932 Globigerina rugosa Plummer ; Sandidge : 367, pl. 33, figs. 11, 12.
1952 Rugoglobigerina (Rugoglobigerina) yvugosa vugosa (Plummer) Bronnimann : 28, text-figs.

Ila—131.

1955 Ee tina (Rugoglobigerina) vugosa vugosa (Plummer) ; Gandolfi: 72, pl. 7, figs.
6a—c ; text-fig. IIc.

1957 Rugoglobigerina rugosa (Plummer) ; Bolli, Loeblich & Tappan : 42, pl. 11, figs. 2a-c.

1960 Rugoglobigerina rugosa vugosa (Plummer) ; Olsson : 50, pl. 10, figs. 16-18.

1962 Rugoglobigerina vugosa (Plummer) ; Berggren: 71-75; pl. 11, figs. 1a—5b; text-fig.

8 (1a—5)).

REMARKS. This species occurs throughout the Maestrichtian part of the sections
studied, being rare at the base and increasing gradually in number towards the top,
where it floods the Middle and Upper Maestrichtian. It was originally described
from the Maestrichtian Upper Navarro formation of Texas, and was later recorded
from the same formation (Bolli, Loeblich & Tappan 1957), from the Maestrichtian
of Alabama (Sandidge 1932), of Trinidad (Brénnimann 1952), of northeastern
Colombia (Gandolfi 1955), of New Jersey (Olsson 1960) and of Scandinavia (Berggren
1962).

HypotyPe. P.45655.

HORIZON AND LOCALITY. Hypotype from sample No. 18, W. El-Sharawna
section.

Genus TRINITELLA Broénnimann 1952
TYPE SPECIES. Tvimitella scotti Bronnimann 1952.

1952 Tvinitella Bronnimann : 56 (Type species : Tvinitella scotti Bronnimann 1952).

Remarks. Tvimitella Bronnimann 1952 is morphologically transitional between
Globotruncana Cushman 1927 and Rugoglobigerina Bronnimann 1952. It is dis-
tinguished from the former by the lack of an entire keel or keels and an imperforate
peripheral band, and from the latter by its compressed last chamber or chambers
and partially developed keel. The fact that this genus is monotypic, may suggest
its inclusion in either Rugoglobigerina (to which it is more closely related) or Globo-
truncana. However, as it does not conform to the present definition of either of these
genera, it is best treated separately until further study can reveal its true position.

150 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

Trinitella scotti Bronnimann

1952 Tvinitella scotti Bronnimann : 57, pl. 4, figs. 4-6; text-figs. 30a—m.
1956 Tvinitella scottti Bronnimann ; Broénnimann & Brown : 555, pl. 23, figs. 13-15.
1957 Rugoglobigerina scotti (Bronnimann) Bolli, Loeblich & Tappan : 43, pl. 11, figs. 3a—4c.

REMARKS. Tvinitella scotti has been recorded from the Middle and Upper Maest-
richtian of the studied sections (the G. ganssevi and the G. esnehensis Zones). It is
generally rare at the base of the Middle Maestrichtian, but gradually increases in
number upwards in the section becoming common to abundant. The species was
originally described from the Maestrichtian of Trinidad and was later recorded from
the Maestrichtian of Texas, Arkansas, Alabama, Puerto Rico and Cuba (Brénnimann
& Brown 1956) and from that of Trinidad and Texas (Bolli, Loeblich & Tappan 1957).

HypotyPe. P.45656.

HORIZON AND LOCALITY. Hypotype from sample No. 19, W. El-Sharawna
section.

Family ROTALIPORIDAE Sigal 1958
Subfamily HEDBERGELLINAE Loeblich & Tappen 1961
Genus HEDBERGELLA Bronnimann & Brown 1958
TYPE SPECIES. Anomalina lorneiana d’Orbigny var. trocoidea Gandolfi 1942.

Remarks. The genus Hedbergella as defined by Broénnimann & Brown (1958)
and emended by Loeblich & Tappan (1961, 1964) only differs from Praeglobotruncana
Bermudez 1952, in lacking a keel or a poreless margin, and thus was included as a
subgenus of the latter by Banner & Blow (1959). However, the two forms are here
treated separately, although further study may prove the non-carinate forms to
have evolved imperceptibly into the carinate ones, as is the case in the genus Globo-
rotalia Cushman 1927 (see below). This may be substantiated by the fact that the
keel in Praeglobotruncana is generally weakly developed and that forms of Hedbergella
with pseudo-keel and/or a pinched out periphery have been recorded. Again, the
general tendency towards the development of more flattened chambers (characteristic
of Praeglobotruncana) from the globular ones (characteristic of Hedbergella) are also
documented. However, as only the youngest representatives of this genus are
recorded in the present study, no firm conclusion regarding their ancestry could be
reached. The classification proposed by Loeblich & Tappan (1961, 1964) has there-
fore been temporarily accepted.

Hedbergella hessi compressiformis (Pessagno)

1962 Praeglobotruncana hessi compressiformis Pessagno : 360, pl. 5, figs. 1-7.

Remarks. Hedbergella hessi compressiformis is rare in the upper part of the
Lower Maestrichtian and in most of the Middle Maestrichtian of the sections studied.
The species was originally described from the Maestrichtian Rio Yauco formation
of Puerto Rico.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT I51L

HypotyPe. P.4566r.

HORIZON AND LOCALITY. Hypotype from sample No. 16, Gebel Owaina section.

Hedbergella hessi hessi (Pessagno)
1962 Praeglobotruncana hessi hessi Pessagno : 358, pl. 5, figs. 8-12.

REMARKS. A few specimens of Hedbergella hessi hessi are recorded from the upper
part of the Lower Maestrichtian (G. fornicata Zone) of the sections studied. It
continues as a rare form up to the basal part of the Upper Maestrichtian (G. esnehensis
Zone) where it dies out completely. The species was originally described from the
Maestrichtian Rio Yauco formation of Puerto Rico.

HypotyPe. P.45662.

HORIZON AND LOCALITY. Hypotype from sample No. 16, Gebel Owaina section.

Hedbergella mattsoni (Pessagno)

1960 Pyraeglobotruncana mattsont Pessagno : 98, pl. 2, figs. 1-3, 6-8.
1962 Praeglobotrvuncana mattsoni Pessagno ; Pessagno : 358, pl. 5, figs. 14-16.

REMARKS. Hedbergella mattsoni is rare in the Lower Maestrichtian and in the
base of the Middle Maestrichtian of the sections studied. It was originally described
from the Maestrichtian Rio Yauco formation of Puerto Rico.

HypoTyPeE. P.45663.

HORIZON AND LOCALITY. Hypotype from sample No. 20, Wadi El-Sharawna
section.

Hedbergella monmouthensis (Olsson)

1960 Globorotalia monmouthensis Olsson : 47, pl. 9, figs. 22-24.
1962 Praeglobotruncana (Hedbergella) monmouthensis (Olsson) Berggren : 37-41, pl. 8, figs.
ta—3c ; text-figs. 4 (1a—5c).

REMARKS. Hedbergella monmouthensis appears in the uppermost part of the Lower
Maestrichtian (G. fornicata Zone) of the sections studied. It increases gradually
in numbers upwards in the section, becoming common in both the Middle and Upper
Maestrichtian (the G. gansseri and the G. esnehensis Zones) ; it dies out completely
just below the conglomerate separating the Maestrichtian from the overlying Danian.
The species was first described as Globorotalia monmouthensis by Olsson (1960), from
the Maestrichtian Redbank formation of New Jersey, but the well developed umbili-
cal portici clearly distinguish it from Globorotalia and justify its position in Hedberg-
ella. The species was also recorded from the Upper Maestrichtian of Scandinavia
(Berggren 1962) and from the Maestrichtian of Belgium, Holland and Scandinavia
(Hofker 1956a, 1957a, 1958a, 1959e, 1960a, 1960d, 19607), where the latter author
confused it with Globorotalia pseudobulloides (Plummer), G. compressa (Plummer),
G. quadvata White, and Globigerina linaperta Finlay. Similarly, most records of

152 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

Globorotalia and Globigerina species from Maestrichtian strata, probably belong to the
present species.

HypotyrPe. P.45664.

HORIZON AND LOCALITY. Hypotype from sample No. 21, Wadi El-Sharawna
section.

Hedbergella petaloidea (Gandolfi)

1955 Globotruncana (Rugoglobigerina) petaloidea petaloidea Gandolfi: 52, pl. 3, figs. 13a-c.

1955 Globotyuncana (Rugoglobigerina) petaloidea subpetaloidea Gandolfi: 52-53, pl. 3, figs.
12a-c.

1956 Globigerina compressa Plummer ; Hofker : 76, pl. 9, figs. 67a-c.

1960 Rugoglobigerina jerseyensis Olsson : 49, pl. 10, figs. 19-21.

1962 Praeglobotruncana (Hedbergella) petaloidea (Gandolfi) ; Berggren : 41-43, pl. 7, figs. 4a—c.

REMARKS. Hedbergella petaloidea ranges throughout the Maestrichtian part of the
sections studied as a rare to common form. It is believed to have evolved into
Globotruncana havanensis Voorwijk by the lateral compression of the chambers in the
last whorl, by the development of a roughly concavo-convex test, by the confinement
of the aperture to an interiomarginal-umbilical position, and by the development of
the umbilical tegilla, the keel or keels and the imperforate peripheral band. This
is suggested by the recorded tendency of H. petalotdea to shift the aperture to a some-
what umbilical position and to develop a pinched out pseudo-keel and slightly
compressed chambers, and is substantiated by the several transitional stages which
were described by Gandolfi as G. (R.) pfetaloidea subpetaloidea. However, both
Gandolfi (1955) and Berggren (1962) considered H. petaloidea to have evolved from
G. havanensis, despite the fact that the general tendency in the evolution of these
forms is towards the development of carinate tests and more flattened chambers.

The species was originally described by Gandolfi (1955) from the Maestrichtian
Colon shale of northeastern Colombia as Globotruncana (Rugoglobigerina) petaloidea
petaloidea. However, its extraumbilical-umbilical aperture and weakly developed
umbilical portici distinguish it from both Globotruncana and Rugoglobigerina, and
justify its assignment to Hedbergella. Again, the form described by Gandolfi (1955)
as G. (R.) petaloidea subpetaloidea differs from the present species in having only a
weakly developed pseudocarina. However, as the tendency to have a pinched out
periphery in the form of a pseudocarina was clearly observed in the central form, the
latter subspecies falls well within its range of variation and is thus considered
synonymous.

Olsson (1960) described as R. jerseyensis from the Maestrichtian Redbank forma-
tion of New Jersey, a form which is identical with the present species, while Hofker
(1956c) confused it with G. compressa (Plummer) when he described the latter species
from the Maestrichtian of northwestern Germany.

HypotyPe. P.45665.

HoRIZON AND LOCALITY. Hypotype from sample No. 27, Wadi El-Sharawna
section.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 153

Family GLOBIGERINIDAE Carpenter, Parker & Jones 1862
Subfamily GLOBIGERININAE Carpenter, Parker & Jones 1862
Genus GLOBIGERINA dOrbigny 1826
TYPE SPECIES. Globigerina bulloides d’Orbigny 1826.

1826 Globigerina d’Orbigny : 277 (Type species : Globigerina bulloides d’Orbigny 1826).

1956 Globoconusa Khalilov : 249 (Type species : Globoconusa conusa Khalilov, 1956).

1961 Subbotina Brotzen & Pozaryska : 160 (Type species : Globigerina triloculinoides Plummer
1926).

EMENDED DIAGNOsIS. Test free, trochospirally coiled, multiglobular ; dorsal side
evolute, low trochospire or turreted ; ventral side umbilicate, strongly inflated ;
equatorial periphery subcircular to ovoid, moderately to distinctly lobate ; axial
periphery rounded ; chambers arranged in 2—4 whorls, dextrally or sinistrally coiled;
all chambers seen on dorsal side, only those of last whorl seen on ventral side ;
chambers generally spherical, ovate, slightly elongated radially or in direction of
coiling, strongly inflated, but occasionally slightly compressed or gently appressed ;
inter-cameral sutures on dorsal side curved or straight, depressed ; on ventral side
generally radial and strongly depressed ; spiral suture curved, or rectispiral, depres-
sed ; umbilicus very small or large, open ; aperture interiomarginal, umbilical,
sometimes extending slightly towards the periphery, not as much as in Globorotalia,
and sometimes provided with apertural lip ; previous apertures remain open into
the umbilicus ; wall calcareous, perforate, radial in structure ; surface smooth,
cancellated, pitted, reticulate, papillose, hispid or spinose.

Discussion. d’Orbigny’s original description of the genus Globigerina was so
brief that several other genera, e.g. Globorotalia, Hedbergella, Rugoglobigerina and
Globotruncana, were included in it, thus obscuring its stratigraphical range. How-
ever, Globigerina is distinguished by its globular, non-truncated chambers ; interio-
marginal, umbilical apertures (which may in some cases extend slightly towards the
periphery), its simple, open umbilicus and rounded axial periphery. Recent
studies have defined the range of this genus as Danian—Recent, although it was
previously extended to the Lower Cretaceous or even to the Upper Jurassic. How-
ever, the fact that no typical Globigerina has yet been recorded from the Upper
Cretaceous makes the stratigraphical gap between the first appearance of Globigerina
in the Lower Danian and the so-called Globigerina in the Upper Jurassic and the
Lower Cretaceous too big, and casts doubt on the identification of the latter forms.
Whether Globigerina is a polyphyletic genus which in the Upper Jurassic, branched
off from a particular ancestor to die out in the Lower Cretaceous, and again from
another ancestor in the basal Danian branched off to continue living up to now
(as suggested by Bolli, Loeblich & Tappan 1957), or whether the Upper Jurassic—
Lower Cretaceous forms are not true globigerinas are questions still unanswered,
although the latter proposition seems most probable.

Khalilov (1956) described Globoconusa as a new genus, with Globoconusa conusa
Khalilov as type species. It was distinguished by its high conical, turret-like test,

154 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

although Globoconusa quadripartitaformis Khalilov 1956 was described as having a
convex, rather than a turreted dorsal side. Globoconusa conusa Khalilov is a junior
synonym of Globigerina daubjergensis Bronnimann 1953 a species which shows a
marked variation in the height of its spire. Again, variation in the degree of eleva-
tion of the dorsal side is clearly observed within one and the same species, and between
one species and another, and cannot be accepted as a generic character. Typical
globigerinas with a highly raised dorsal side are known, and in the other closely
related planktonic genera, forms with planoconvex, biconvex and spiroconvex test
are included within the same genus and cannot be separated on the basis of the
shape of the dorsal side.

Loeblich & Tappan (1964) emended the diagnosis of Globoconusa Khalilov adding,
that the wall is characteristically spinose and that the aperture is a small, rounded
umbilical opening, with one or more tiny, secondary sutural openings on the spiral
side against the early whorl. However, they stated “‘ Although Globoconusa was
described as high-spired, the type species is quite variable as to height of spire.”’
Again the holotype of Globoconusa conusa was described as having an umbilical
aperture only, with no sutural apertures, as was its senior synonym Globigerina
daubjergensis Bronnimann. Finally, if the surface spines are considered character-
istic of the genus, it would not be possible to decide to which genus forms such as
Globigerina kozlowski Brotzen & Pozaryska (with a highly turreted spiral side and a
delicately papillose surface) should be assigned.

Globoconusa Khalilov, as originally defined by its author, is a junior synonym of
Globigerina d’Orbigny 1826. Forms with minute sutural apertures which were
assigned to this genus by Loeblich & Tappan (1964) are not typical and should
preferably be treated separately.

Morozova (1959) described Globigerina (Eoglobigerina) as a new subgenus, with
G. (E.) eobulloides Morozova as type species. It was said to differ from Globigerina
(Globigerina) d’Orbigny in its thin and smooth or microcellular test wall, and in the
small size of its aperture. However, surface texture and size of aperture are charac-
ters of specific rather than subgeneric importance. Furthermore, since Globigerina
(Eoglobigerina) eobulloides is a junior synonym of Globorotalia pseudobulloides
(Plummer), G. (Eoglobigerina) is a junior synonym of Globorotaiia Cushman. It
should be noted that Morozova apparently included within Globigerina (Eoglobiger-
ina) some Senonian species of Hedbergella, thus considering its range to be Senonian to
Danian.

Brotzen & Pozaryska (1961) described Subbotina as a new genus, with Globigerina
triloculinoides Plummer 1926 as the type species. Swubbotina was said to differ from
Globigerina d’Orbigny in having a reticulate surface with large pores which open on
the surface in two funnel-shaped structures surrounded by a coronet or radiating
pillars. These authors studied the wall structure of Globigerina bulloides d’Orbigny
and concluded that it is completely different from the reticulate wall of Globigerina
triloculinoides. As they found no transitional stages between these two types of wall
texture, they separated the globigerinas with a reticulate surface as their new genus
Subbotina, stating that “ Le type réticulé ... se trouve dans tout un group de

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 155

prétendues Globigerina, mais étant donné que nous n’avons jamais trouvé trace de
passage dans notre matériel ou dans le matériel publié, nous devons nous considérer
comme obligés de séparer taxinomiquement ce groupe de Globigerina et de lui donner
un nouveau nom de genre : Subbotinan.gen.”” However, both Hofker (1960g, 7) and
Berggren (1962) suggested the development of Globigerina triloculinoides Plummer,
from Globorotalia pseudobulloides (Plummer), a species with a very finely pitted
surface, which is believed to have evolved from forms with a smooth, finely perforate
surface (see Berggren 1962: 90). Again, G. triloculinotides Plummer is believed to
have evolved into G. inaequispiva Subbotina, a species with a less reticulate surface.
Moreover, the surface texture in the various species of Globigerina varies from smooth,
to hispid, papillose, nodose, spinose, pitted or reticulate. Variation in the surface
texture from one species to another, and amongst members of the same species
excludes the possibility that this feature alone can be used as a generic character.
Thus the separation of globigerinas with a reticulate surface as a distinct genus
cannot be accepted without a complete study of the various forms of surface texture
and of their relationship to each other through the various evolutionary lineages in
Globigerina. It is believed that different types of surface texture grade imper-
ceptibly into one another. The suggested lineages in Globigerina (Text-fig. 13) show
the gradual evolution of highly spinose, nodose forms from smooth-surfaced ones.
Thus Subbotina Brotzen & Pozaryska 1961 is here considered a junior synonym of
Globigerina d’Orbigny 1826.

Loeblich & Tappan (1964) emended the diagnosis of Swbbotina, adding that the
aperture is umbilical-extraumbilical, and stating that “‘ The coarsely pitted surface
is found in species with low and slightly extraumbilical aperture and distinctive lip,
none of which is found in typical Globigerina.’’ However, most Globigerina species
show a slight tendency towards the extension of the aperture to a somewhat extra-
umbilical position, but not as much as in true Globorotalia. Again, variation in the
degree of elevation of the dorsal side, in the development of the apertural lip, and in
surface texture are characters of specific, rather than generic importance. Moreover,
Subbotina was described as having the same stratigraphical range as Globigerina
d’Orbigny.

ReMARKS. Eighteen species and subspecies of Globigerina are described in the
present study, four species and one subspecies of which are new. These new forms
are: Globigerina alanwoodi sp.nov., G. arabica sp.nov., G. haynesi sp.nov., G. nodosa
sp.nov., and G. triloculinoides parva subsp.nov.

EVOLUTIONARY DEVELOPMENT OF GLOBIGERINA

The genus Globigerina was always thought to be the ancestral stock from which
most globigerinids evolved, because its range was wrongly considered to be Upper
Jurassic to Recent. However, as explained earlier, the Mesozoic records are probably
incorrect. Moreover, the widespread faunal break between the Maestrichtian and
the Danian makes it difficult to follow the early evolutionary development of the genus.
Whether Globigerina has evolved from Rugoglobigerina by the loss of the tegilla and
the meridional costellae, from Hedbergella by the confinement of the aperture to an

156 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

interiomarginal, umbilical position and by the loss of the umbilical portici, or from
the rounded Globorotalia by the confinement of the aperture to an interiomarginal,
umbilical position, is still unknown. Nevertheless the recorded development of
Globigerina triloculinoides Plummer from Globorotalia pseudobulloides (Plummer) (see
Hofker 1960g, 7 ; Berggren 1962) may favour the last-mentioned proposition.

The present study of early representatives of the genus Globigerina throughout the
Paleocene—Lower Eocene succession of the Esna—Idfu region has shown that the
genus displays a marked tendency to increase its surface rugosity upwards in the
section (see Text-fig. 13)

Globigerina alanwoodi sp. nov.
(Pl. 16, figs. 6a—c)

Diacnosis. A Globigerina with large, robust, smooth-walled, multilocular test ;
weakly raised dorsal side and strongly inflated ventral one ; numerous, inflated
chambers which increase slowly in size ; wide umbilicus.

DESCRIPTION. Test large, robust, coiled in a low trochospire ; dorsal side almost
flat, sightly inflated, with the early chambers very weakly raised over the circumam-
bient last whorl ; ventral side strongly inflated and distinctly protruding ; equatorial
periphery circular, slightly lobate ; axial periphery rounded ; chambers on the dorsal
side 17, arranged in 3 dextrally coiled whorls ; the initial chambers are comparatively
large, globular, slightly inflated and are followed by roughly ovoid, moderately
inflated ones which are elongated in the direction of coiling and increase regularly in
size ; the last whorl is composed of 7 large chambers which are crescentic in the early
part, roughly quadrangular later, strongly elongated in the direction of coiling and
increase slowly and regularly in size, except for the last chamber which is slightly
smaller than the penultimate ; on the ventral side the chambers are 7, large, inflated
and strongly protruding ; sutures on the dorsal side slightly curved, depressed ; on
the ventral side they are straight, radial and strongly incised ; umbilicus wide, deep
and open, aperture interiomarginal, umbilical ; wall calcareous, perforate ; surface
smooth, except around the umbilicus where it becomes delicately papillose.

DIMENSIONS OF HOLOTYPE.

Maximum diameter = 0-47 mm.
Minimum diameter = 0-41 mm.
Thickness = 0°30 mm.

REMARKS. Globigerina alanwoodi sp. nov. is closely related to G. mckannai
White from which it is distinguished by its perfectly smooth surface, and distinct
stratigraphical range. It probably evolved into G. mckannai in Upper Paleocene
time by the development of the granular spinose surface. On the other hand, it
possibly evolved from the smooth surfaced, multilocular, G. spiralis Bolli, by flatten-
ing the dorsal side, increasing the size of test and the number of chambers in the last
whorl and by developing a much wider umbilicus. The stratigraphical ranges of
these forms agree with this proposition, although no direct evidence was recorded.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 157

This species is named after Professor Alan Wood, of the Department of Geology,
U.C.W., Aberystwyth

HoLotyPe. P.45567.
PARATYPES. P.45568.

HorizoON AND LOCALITY. MHolo- and paratypes, from sample No. 43, Gebel
Owaina section.

STRATIGRAPHICAL RANGE. Globigerina alanwoodt is restricted to the lower Upper
Paleocene, ranging throughout the G. pseudomenardi Subzone as a rare to “ flood ”’
form in the sections studied.

Globigerina aquiensis Loeblich & Tappan

19574 Globigerina aquiensis Loeblich & Tappan : 180, pls. 51, figs. 4a—5c ; pl. 56, figs. 4a—6c.
? 1960a Globigerina aquiensis Loeblich & Tappan; Berggren: 65-66, pl. 1, figs. 1a—2c ;
pl. 7, figs. 1a—2c.

REMARKS. Globigerina aquiensis was first described by Loeblich & Tappan
(1957a) from the Aquia formation of Maryland and Virginia and the Vincentown
formation of New Jersey, which they considered to be of Upper Landenian (Sparn-
acian) age.

Berggren (1960a) described this species from the Lower Eocene of northwestern
Germany, while Gartner & Hay (1962) recorded it from the type Ilerdian of Spain
and the Ilerdian “‘ marne blanche”’ of Mont Cayala, France. The latter authors
included G. kozlowski Brotzen & Pozaryska in the synonymy of this species, although
the morphological characters and stratigraphical distribution of these two species
strongly oppose this proposition.

Globigerina aquiensis is distinguished by its small, inflated, moderately to relatively
high, trochospirally coiled test ; its chambers which increase moderately in size and
which are elongated in the direction of coiling ; its small umbilicus ; and finely hispid
surface. It is very closely related to G. haynes: sp. nov. (p. 165) from which it has
probably evolved, and to G. pseudocorpulenta Khalilov which might possibly have
evolved from it, although no direct evidence was recorded.

In the Esna—Idfu region, G. aquiensis is rare in the upper part of the G. velasco-
ensis Zone, the G. aequa/G. esnaensis Subzone of Upper Paleocene age, and gradually
fades out in the overlying Lower Eocene G. wilcoxensis Zone.

HypotyPe. P.45569.

HORIZON AND LOCALITY. Hypotype from sample No. 63, Gebel Owaina section.

Globigerina arabica sp. nov.
(Pl. 18, figs. 6a—c)

DiaGnosis. A Globigerina with large, moderately to highly spired, smooth-
walled test ; radial, incised sutures on both sides ; chambers increasing slowly in size.

158 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

DeEscrRIPTION. Test large, globular, inflated and coiled in a high trochospire ;
dorsal side convex, strongly inflated with the early chambers almost on the same
level and distinctly raised above those of the last whorl ; ventral side moderately
inflated ; equatorial periphery subcircular, distinctly lobate ; axial periphery
rounded ; the 18 chambers on the dorsal side increase slowly in size and are arranged
in 24 dextrally coiled whorls ; the last whorl is composed of 6, large, subglobular
chambers ; on the ventral side the chambers are 6, large, globular, strongly inflated
and increase slowly in size except for the third which is much smaller than the others ;
sutures on both sides almost straight, radial and strongly depressed ; umbilicus
small, deep and open (although it is filled with calcite growth and foreign material in
the figured specimen) ; aperture interiomarginal umbilical, an ovoid, large opening
with thick calcite growth around it ; wall calcareous, perforate ; surface smooth.

DIMENSIONS OF HOLOTYPE.

Maximum diameter = 046 mm.
Minimum diameter =") 0-30 uma:
Maximum thickness = 0:29 mm. (across the middle part of test)

VARIATION. The main variation observed is in the degree of elevation of the
dorsal side which can be either weakly raised or coiled in a very high trochospire ;
coiling is random, with more tendency to dextral forms.

REMARKS. Globigerina arabica sp. nov. is distinguished from G. spiralis Bolli by
its much larger size, less elevated initial spire and more globular, inflated chambers.
In G. spiralis each whorl is higher than the following one and thus the dorsal side is
more or less conical in shape, while in G. avabica the first two whorls are more or less
in the same level but distinctly higher than the last.

The presence of the peculiar calcite growth in the umbilicus and around the
aperture made it difficult to determine the taxonomic position of this species with
certainty. It is, therefore, included in Globigerina for the time being on the basis of
its other morphological features.

Globigerina arabica has probably evolved from Globorotalia trinidadensis Bolli by
the elevation of the early whorls, the reduction of the rate of growth, and the confine-
ment of the aperture to an interiomarginal, umbilical position. Forms of G. tvimi-
dadensis with slightly raised early chambers are believed to be transitional to the
present species. G. arabica is also believed to have evolved into G. spiralis Bolli, as
substantiated by the morphological characters and stratigraphical distribution of
these two species.

HOLoTyPeE. P.45570.
PARATYPES. P.45571.

HorRIZON AND Locality. Holo- and paratypes, from sample No. 30, Gebel
Owaina section.

STRATIGRAPHICAL RANGE. Globigerina arabica sp. nov. ranges throughout the
Upper Danian part of the sections studied, (the Lower and Middle Danian being
missing). It does not cross the Danian—Middle Paleocene boundary.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 159

Globigerina bacuana Khalilov
1956 Globigerina bacuana Khaliloy : 235, pl. 3, figs. 4a—c.

REMARKS. Globigerina bacuana Khaliloy is one of three morphologically similar
Globigerina species which are distinguished from each other by the surface texture.
These three species are :

1. Globigerina bacuana Khalilov, 1956, with a densely pitted surface.

2. Globigerina aquiensis Loeblich & Tappan 19574, with a finely hispid surface.

3. Globigerina haynesi sp. nov. with a delicately papillose surface.

Globigerina bacuana is distinguished by its large, robust test which is coiled in a low
to moderately high trochospire ; its 4 large, subglobular, chambers in the last whorl
which increase rapidly in size ; its almost straight, radial, depressed sutures ;
narrow umbilicus ; and distinctly pitted surface. It is believed to have evolved
from G. haynesi sp. nov. by the development of the pitted surface.

HypotTypPe. P.45572.
HORIZON AND LOCALITY. Hypotype from sample No. 60, Gebel Owaina section.

STRATIGRAPHICAL RANGE. Globigerina bacuana was first described by Khalilov
(1956) from the Upper Paleocene and the Lower Eocene of Azerbaidzhan and
Turkman, U.S.S.R.

In the Esna—Idfu region G. bacwana occurs as a rare form in the upper part of the
G. velascoensis Zone, the G. aequa/G. esnaensis Subzone of upper Upper Paleocene age.

Globigerina belli White
1928a Globigerina belli White ; 192, pl. 27, figs. 11a—c.

Remarks. Although White’s original figures are not clear and his description is
incomplete, the present form most probably belongs to this species.

Globigerina bell: White is distinguished by its large, globular, trochospirally coiled
test ; raised dorsal side and inflated ventral one ; numerous, large roughly globular
chambers which increase moderately in size on the dorsal side (except for the last,
which is generally smaller than the penultimate and strongly elongated and curved
over the ventral side thus covering most of the umbilicus) ; chambers on the ventral
side inflated, globular, slowly increasing in size ; last chamber peculiar in shape ;
straight, incised sutures on both sides ; narrow umbilicus ; and sugary-textured
surface.

G. belli is probably the ancestral stock from which most of the multilocular,
highly-spired Paleocene Globigerina species have evolved. It has possibly evolved
directly into G. spiralis Bolli, or indirectly via G. arabica sp. nov., although no direct
evidence was recorded.

HypotypPe. P.45573.

HORIZON AND LOCALITY. Hypotype from sample No. 7, Gebel El-Kilabiya
section.

160 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

STRATIGRAPHICAL RANGE. Globigerina belli was described by White (1928) as
‘“ being of rare occurrence in the uppermost Mendez, becoming common in the very
base of the Velasco, and rapidly diminishing, till disappearing a short distance above
the base’. Apparently, White confused the present species with morphologically
similar Rugoglobigerina species from the Upper Maestrichtian, and thus extended its
range to the uppermost Mendez. However, in the Esna—Idfu region G. belli occurs
as a rare form in the Danian G. compressa/G. daubjergensis Zone and in the basal part
of the overlying G. angulata Zone of Middle Paleocene age.

Globigerina chascanona Loeblich & Tappan
(Pl. 16, figs. 4a—c)
1957a Globigerina chascanona Loeblich & Tappan: 180-181, pls. 49, figs. 4a—-5c; pl. 61,
figs. 8a—c.
1960a Globigerina chascanona Loeblich & Tappan ; Berggren : 66-67, pl. 1, figs. 3a-c ; pl. 7,
figs. 3a—4¢.

DeEscrIPTION. Test medium-sized, coiled in a moderately high trochospire,
inflated ; dorsal side slightly raised, with the early whorls moderately elevated above
the level of the final whorl ; ventral side quadriglobular, strongly inflated ; equatorial
periphery subquadrate to roughly ovoid, lobate ; axial periphery rounded ; chambers
on the dorsal side about 12 in number, increasing moderately in size and arranged in
24 sinistrally coiled whorls ; the initial chambers are small, inflated, globigerine,
almost masked by the surface rugosity and are followed by large, roughly ovoid
chambers ; the last whorl is composed of 43, large, slightly ovoid to roughly quadrate
chambers ; on the ventral side the chambers are 44, large, globular, strongly inflated,
overlapping and pushed forward towards the much-narrowed umbilicus ; sutures on
the dorsal side short, very slightly curved to almost straight, depressed ; on the
ventral side they are slightly curved, almost radial and strongly depressed ; umbilicus
very narrow, shallow and open, with the last chamber strongly pushed over it ;
aperture interiomarginal, umbilical ; surface distinctly nodose, with the nodes taper-
ing out especially along the periphery and on the ventral side in the form of thick
stout, spine-like projections, giving the surface a very prominently spinose appear-
ance.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter = -O-35unim,
Minimum diameter == (O32 iim.
Thickness = 0-28 mm.

REMARKS. This species is distinguished by its small to medium-sized, tightly
coiled, medium to relatively highly spired, prominently spinose test ; its narrow
umbilicus ; overlapping chambers on the ventral side, and slightly curved depressed
sutures.

Loeblich & Tappan (1957a) showed a wide range of variation in the degree of
elevation of the dorsal side of G. chascanona, from a very highly trochospirally
coiled test and a high, conical dorsal side in their holotype (pl. 49, figs. 5a—c), to

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 161

forms with a moderately convex dorsal side (e.g. pl. 49, figs. 4a—c) or even a flat dorsal
side (e.g. pl. 61, figs. 8a—c).

Globigerina chascanona has probably evolved from G. aquiensis Loeblich & Tappan,
by the development of the prominently spinose surface. The morphological
characters and stratigraphical ranges of the two species support this proposition.

Specimens of G. chascanona from the Esna—Idfu region conform well with Loeblich
& Tappan’s original description and figures although they are slightly larger.

HypotypPe. P.45574.

HORIZON AND LOCALITY. Figured specimen from sample No. 64, Gebel Owaina
section.

STRATIGRAPHICAL RANGE. Loeblich & Tappan (1957a) described G. chascanona
from the Hornerstown formation of New Jersey and the Aquia formation of Virginia,
as well as from the Nanafalia formation of Alabama which they considered as Upper
Landenian (Sparnacian) and Lower Eocene respectively. But, as previously
mentioned, both Bramlette & Sullivan (1961) and Gartner & Hay (1962) considered
the Nanafalia formation to be of Paleocene rather than of Lower Eocene age.

G. chascanona was also recorded from the Lower Eocene of northwestern Germany
(Berggren 1960a), and from the type Ilerdian of Spain (Gartner & Hay 1962),
although Berggren’s forms appear to be somewhat different from the type specimens
of G. chascanona.

In the Esna—Idfu region, G. chascanona is rare in the upper part of the Upper
Paleocene G. velascoensis Zone and dies out completely below the overlying Lower
Eocene G. wilcoxensis Zone.

Globigerina daubjergensis Brénnimann
(Pl. 15, figs. 3a-c)

1953 Globigerina daubjergensis Bronnimann : 340-341, text-fig. 1.

1956 Globoconusa conusa Khalilov : 249, pl. 5, figs. 2a—c.

1957) Globigerina daubjergensis Bronnimann ; Bolli: 70, pl. 16, figs. 13-15.

1957 Globigerina daubjergensis Bronnimann ; Troelsen: 128, pl. 30, figs. 1a—2c.

1957a Globigerinoides daubjergensis (Bronnimann) Loeblich & Tappan (pars) : 184-185, pl. 40,
? figs. 1a—c, 8a—c ; pl. 41, figs. ga—-c ; pl. 42, ? figs. 6a—7c ; pl. 43, figs. ta-c ; pl. 44, ? figs.
7-8c.

1959a Globigerina daubjergensis Bronnimann ; Hofker : 22, text-fig. 5.

1960 Globigerinoides daubjergensis (Bronnimann) : Olsson: 43. pl. 8, figs. 4-6.

1960a Globigerina daubjergensis Bronnimann primitiva Hokfer (pars) : 226, ? text-fig. 25 ;
228, text-fig. 34.

1960a Globigerina cf. daubjergensis Bronnimann ; Hofker : 228, text-fig. 36.

1960d Globigerina daubjergensis Bronnimann ; Hofker (pars) : 34-41, pl. 3, (? Danian II,
Danian III, Danian IV, non Danian V, non white chalk of Denmark ; non Cr 4, non Mc,
? holes in hard ground, non Lower Paleocene of Holland) ; non pl. 1, figs. B, E ; non pl. 2,
fig. B.

1960g Globigerina daubjergensis Bronnimann ; Hofker : 74-76, text-figs. 29a-34), table 4.

19602 Globigerina daubjergensis Bronnimann ; Hofker : 119-120, pl. 1, figs. 1-8.

DESCRIPTION. Test very small, coiled in a high trochospire ; dorsal side broadly
conical with a sharply pointed initial part and inflated later part ; ventral side

162 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

quadriglobular, inflated ; equatorial periphery quadrate, distinctly lobate ; axial
periphery rounded ; chambers on the dorsal side appear to be 16-19 in number,
arranged in 4 dextrally coiled whorls ; the initial chambers are extremely small,
indistinct, slightly inflated, globigerine and increase slowly and regularly in size to
the beginning of the last whorl, where the chambers increase rapidly in size ; the last
whorl thus constitutes most of the test, while the early chambers constitute a minute,
high, trochoid spire ; the last whorl is composed of 4, relatively large, almost globular
chambers ; on the ventral side the chambers are 4, relatively large, globular and
inflated ; sutures on the dorsal side curved, depressed in the early part, straight
and strongly incised later ; on the ventral side the sutures are straight, radial,
strongly incised, set almost at right angles to each other in a cruciform pattern which
emphasizes the quadrate shape of the test ; umbilicus exceedingly small, almost
closed and indistinct ; aperture interiomarginal, umbilical ; wall calcareous, finely
perforate ; surface rough, hispid, covered by minute, delicate spines, and very small
scattered papillae.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter —=)))0:175 im,
Minimum diameter = O:130 mm,
Thickness = 0°60 mam:

MAIN VARIATION.

1. The test is minute to small (maximum diameter ranges from 0-12 to 0:28 mm.)

2. The dorsal spire may be moderately raised to high.

3. The number of chambers in the last whorl is 3-4, 34 is most common.

4. Coiling is fairly random but tends to be dextral ; (of 175 specimens studied, 98
coiled dextrally).

5. The small, shallow, open umbilicus may be partially closed by the slightly
overlapping last chamber.

6. The fine surface spines are always present and may be prominent and numer-
ous or very faint and scattered.

REMARKS. Globigerina daubjergensis Bronnimann is distinguished by its extremely
small, trochospirally coiled test, its minute, pointed spire on the dorsal side, its
rough, finely spinose wall surface, its small shallow umbilicus and small umbilical
aperture, its strongly depressed sutures on both sides, and distinctly lobate periphery.

Because of its extremely small size, this excellent Danian guide fossil was probably
overlooked in the past or lumped together with superficially similar Globigerina
species. Troelsen (1957) recorded this species from the type Danian and from
various Danian outcrops in Scandinavia, where he noticed, for the first time, the
occurrence of small, accessory, sutural apertures on the dorsal side of some of the
specimens. These accessory apertures caused disagreement whether the species
should be referred to Globigerina or to Globigerinoides, and the problem was further
complicated by the fact that specimens with and specimens without accessory
apertures were found together. Troelson added “‘ Small accessory apertures
commonly occur along the sutures of the final chamber, but the writer has, neverthe-

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 163

less, refrained from referring the species to the (probably polyphyletic) genus
Globigerinoides.”’

Bolli (19576), Hofker (1959a, 1960a, d, g, 1, 1961d, 1962a), Bolli & Cita (19602, b),
and Berggren (1962) considered the species to belong to the genus Globigerina
although both Hofker and Berggren clearly described and figured these dorsal open-
ings.

Loeblich & Tappan (1957a, 6) followed by Olsson (1960) and Hillebrandt (1962),
removed this species to the genus Globigerinoides, while Reichel (1953) and Bermudez
(1961) considered it to be a ? Globigerina.

Loeblich & Tappan figured the dorsal views of 7 specimens, only four of which were
shown to have supplementary apertures ; they said nothing about the forms without
supplementary apertures, nor did they say to which genus these forms should be
referred if the species is removed to the genus Globigerinoides. Hofker (1959a,
1960a, d, g, 1, 1961d, 1962a) and Berggren (1962) tried to explain that these dorsal
openings are slight morphological variations in the evolutionary development of the
species, and do not warrant its removal to the genus Globigerinotdes.

These so-called supplementary apertures were not observed in specimens of G.
daubjergensis from the Esna—Idfu region. Broénnimann (personal communication,
April 2, 1963) stated that : “‘ The type of Globigerina daulbjergensis Bronnimann does
not have any additional apertures, and the removal to the genus Globigerinoides does
not seem to be justified.”” Thus, it is here suggested that the typical G. daubjergensis
does not have supplementary apertures, that forms with supplementary apertures
should be considered separately, and that the removal of the species to the genus
Globigerinoides is not warranted. However, in the very closely related Globigerina
kozlowsku Brotzen & Pozaryska which is associated with G. daubjergensis in the
Upper Danian, and is believed to have evolved from it, occasional, minute, sutural
openings were observed, but seem to be different from the typical Globigerinoides
sutural apertures. A detailed study of a whole population of each of these two species
at their type localities is essential to establish their relationship and explain the true
nature of these supplementary apertures. It is not excluded, that forms described
as G. daubjergensis with sutural apertures are actually G. kozlowskw and that the
latter represents the ancestral stock from which the genus Globigerinoides has evolved.

Khalilov (1956) described Globoconusa as a new genus with Globoconusa conusa
Khalilov as type species. Examination of the description and figures of the latter
species showed clearly that it is a junior synonym of Globigerina daubjergensis
Br6énnimann 1953, and that Globoconusa is a junior synonym of Globigerina d’Orbigny
1826, as mentioned above.

Hofker (1959a, 1960a, d, g, 1, 1962a) studied the orthogenetic changes in the
development of G. daubjergensis in the Danian rocks of Denmark, Holland and
Belgium. Apparently he had confused G. daubjergensis with small forms of Mae-
strichtian Rugoglobigerina and Hedbergella species and also with younger Globigerina
species in the overlying Middle Paleocene greensands such as Globigerina kozlowski,
thus obscuring the stratigraphical range and morphological characteristics of the
species. This may be mainly due to the occurrence of mixed Maestrichtian—

164 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

Paleocene fauna in holes in the hard ground on top of the Md of Holland and Den-
mark, and to repeated attempts by Hofker to equate the type Maestrichtian with the
type Danian, and to build bioseries representing continuous evolution from the
Upper Cretaceous to the basal Tertiary.

The evolutionary trends suggested by Hofker (1960g, 7) for G. daubjergensis can
be summarized as follows :

1. A gradual increase in the size of test and a decrease in the density of spines

on the walls of the last-formed chambers upwards in the section.

2. The development of small openings on the dorsal side from the Middle Danian
onwards ; these become more frequent higher in the section.

3. The increase in the size of the last-formed chambers, which may, in the
highest levels of the Danian and in the overlying greensands, cover the
whole umbilical region and the visible aperture (Catapsydrax character).

This clearly shows that Hofker confused G. daubjergensis with forms such as
G. kozlowskwu ; the former was not reported to cross the Danian—Middle Paleocene
boundary, while the latter was reported from the middle and Upper Paleocene
where it was said to display both the Globigerinoides and Catapsydrax characters
assigned by Hofker to G. daubjergensis in its later stages of development. However,
this evolutionary series was partially substantiated by Berggren (1962) in his study
of specimens from southern Scandinavia, but it is probable that he had also confused
G. dawjergensis with the early stages of G. kozlowskit.

In the Esna—Idfu region, it was not possible to follow the evolutionary development
of the species as suggested by Hofker, because the Lower and Middle Danian are
missing. However, the specimens studied show a general tendency to increase the
size of test and to reduce the surface rugosity on the chambers of the last whorl.
Hofker (1960 g, 7) greatly overemphasized the value of these continuous morphological
changes in G. daubjergensis as tools in working out the detailed stratigraphy of the
Danian stage. Without belittling these observations, it has to be stated that the
distinct stages, mentioned by Hofker, are most probably distinct species, and that in
a single species population, a wide range of variation was observed.

The physical and biological break at the base of the Danian made it difficult to
trace the ancestral stock from which G. daubjergensis had evolved. This might have
been any of the apparently similar Rugoglobigerina or Hedbergella forms which flood
the Maestrichtian rocks below. Again, it is believed that G. daubjergensis evolved
into G. kozlowskw since all transitional stages between them have been recorded. On
the other hand, G. daubjergensis is believed to be related to the similarly trocho-
spirally coiled forms, G. chascanona Loeblich & Tappan and G. spiralis Bolli, although
no direct evidence was recorded.

HypotyPe. P.45575.

HORIZON AND LOCALITY. Figured specimen, from sample No. 7, Gebel El-
Kilabiya section.

STRATIGRAPHICAL RANGE. The species was first described from the uppermost
Danian (Zone D) of a quarry southwest of Stavnsbjerg farm, Daubjerg (Davbjerg),
Jutland, Denmark, considered by Berggren (1962) as Middle Danian.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 165

Troelsen (1957 : 127, text-fig. 4) and Berggren (1962 : 18, 84, test-fig. 2) showed
that G. daubjergensis appears for the first time at the base of the Danian in its type
area, and ranges throughout the whole Danian stage of Scandinavia, becoming
particularly abundant in the upper part where it commonly dominates the planktonic
fauna. It was also recorded from the Danian rocks of Denmark, Holland and
Belgium (Hofker 1956a, 1959a, 19604, d, g,1, 1961d, 1962a) ; from the basal Paleocene
Globorotalia trimdadensis Zone of the lower Lizard Springs formation of Trinidad
(Bolli 1957) ; from the Danian of Sweden and of the Gulf and Atlantic Coastal plains
(Loeblich & Tappan 1957a, b) ; from the basal part of the Hornerstown formation of
New Jersey, which is considered of Danian age (Olsson 1960) ; from the Globorotalia
trinidadensis Zone of the Paderno d’Adda section of northern Italy, which is regarded
to be of Lower Danian age (Bolli & Cita 1960a, b) ; from the basal part of the Velasco
formation of Mexico (Lower Danian) (Hay 1960) ; from the Paleocene of Cuba,
Mexico and Venezuela (Bermudez 1961) ; from the Lower Paleocene of the Gubbio
section, Italy (Luterbacher & Premoli Silva 1962) and from the basal Paleocene of
Austria (Hillebrandt 1962).

All reliable references show clearly that G. daubjergensis is an excellent index
fossil for the Danian; that it ranges throughout the whole stage, being most abundant
at its top, and that it does not cross the Danian—Middle Paleocene boundary. All
records of G. daubjergensis from rocks younger than the uppermost Danian are either
erroneous, or of reworked specimens, while all records from rocks older than the basal
Danian are actually Rugoglobigerina or Hedbergella species.

The assignment of the species to the Lower Danian only, as mentioned by Bolli &
Cita (1960a, b) and Hay (1960), is apparently due to the fact that the first-mentioned
authors had included the lower part of the Middle Paleocene, distinguished by the
abundance of G. angulata (White), in their Upper Danian. Hay (1960) recorded
G. compressa (Plummer) as ranging throughout the whole Danian, and G. daubjer-
gensis as ranging through the lower part only, while all reliable references show
that G. daubjergensis ranges throughout the whole Danian, while G. compressa is
restricted to the Upper Danian.

In the Esna—Idfu region, Globigerina daubjergensis floods the Upper Danian part
of the sections studied, (the Lower and Middle Danian being missing) and disappears
completely before the first appearance of G. angulata angulata (White) of Middle
Paleocene age. The apparently similar forms in the Middle Paleocene are actually
G. kozlowskit Brotzen & Pozaryska.

Globigerina haynesi sp. nov.
(Pl. 15, figs. 5a—c)
Diacnosis. A Globigerina with relatively raised dorsal side and moderately

inflated ventral one ; quadrate, lobate equatorial periphery ; depressed sutures :
very narrow umbilicus and delicately papillose surface.

DESCRIPTION. Test medium-sized, coiled in a relatively high trochospire ; dorsal
side subconical, inflated ; ventral side quadriglobular, moderately inflated ; equatorial

166 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

periphery quadrate, distinctly lobate, axial periphery rounded ; chambers on dorsal
side 15, arranged in 24 dextrally coiled whorls and increasing moderately in size ; the
initial chambers are small, globular, inflated and are followed by subglobular or
rather ovoid, large ones ; the last whorl is composed of 4, subglobular and strongly
inflated chambers ; on the ventral side the chambers are 4, large, globular, strongly
overlapping and moderately inflated ; sutures on the dorsal side slightly curved,
strongly depressed ; on the ventral side they are almost straight, radial and strongly
incised ; umbilicus extremely small, almost indistinct, slit-like, shallow and open ;
aperture interiomarginal, umbilical, in the form of a long narrow arch with a delicate,
small lip ; wall calcareous, perforate ; surface finely papillose.

DIMENSIONS OF HOLOTYPE.

Maximum diameter == — 0°37 Inu.
Minimum diameter == O34. Tt,
Thickness == /O"20 maim:

MAIN VARIATION.

1. Chambers 12-16, arranged in 24-3 tightly coiled whorls, and increasing
moderately in size.

2. The last whorl is composed of 3-4 chambers, 4 being most common ; the last
chamber is usually slightly smaller than the penultimate.

3. Coiling is random with a tendency to dextral coiling ; (of 77 specimens
studied, 49 coiled dextrally).

REMARKS. Globigerina haynesi sp. nov. was probably confused with one or more
of the following distinct, but morphologically similar species :
Globigerina bacuana Khalilov
Globigerina spiralis Bolli
Globigerina aquiensis Loeblich & Tappan
Globigerina chascanona Loeblich & Tappan

It is distinguished from G. bacuana by its delicately papillose surface, high dorsal
side, and raised initial whorls. Globigerina spiralis is distinguished by its smooth
surface, greater number of chambers and of whorls, and more tightly coiled test.
Globigerina aquiensis which is morphologically very similar to the present species, has
a finely hispid surface instead of a delicately papillose one ; G. chascanona is distin-
guished by its prominently spinose surface.

Globigerina hayenst is believed to have evolved from G. spiralis Bolli ; specimens
of G. spiralis with a faintly papillose surface are believed to be transitional to G.
haynesi, and the stratigraphical ranges of the two species favour this hypothesis.
On the other hand, G. haynesi probably evolved into G. velascoensts Cushman by
developing a more tightly coiled test, with an angular, depressed spiral suture and a
strongly appressed last chamber.

This species is named after Dr. J. R. Haynes of the Department of Geology,
U.C.W., Aberystwyth.

HoLotyPeE. P.45576.
PARATYPES. P.45577.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 167

HorRIzoN AND LocALITy. Holo- and paratypes from sample No. 64, Gebel
Owaina section.

STRATIGRAPHICAL RANGE. The species is common to abundant throughout the
Middle and Upper Paleocene of the sections studied, and is rare in the uppermost part
of the Danian.

Globigerina inaequispira Subbotina
(Pl. 15, figs. 8a—c)
1953 Globigerina inaequispiva Subbotina : 69, pl. 6, figs. 1a—4ce.

DeEscripTION. Test large, almost triglobular, coiled in a low trochospire, and
strongly inflated especially on the ventral side ; equatorial periphery almost trilobate,
radially elongate, with each lobe perfectly rounded at the end and distinctly separa-
ted from the others ; axial periphery rounded ; chambers on the dorsal side 15,
arranged in 3 dextrally coiled whorls ; the initial chambers are extremely small,
globular, inflated, very tightly coiled ; they increase slowly in size, and are followed
by relatively much bigger, globular and strongly inflated chambers which increase
gradually in size towards the beginning of the last whorl ; the chambers increase
slowly to moderately in size within the same whorl, but very rapidly from one whorl
to another ; the last whorl, which constitutes most of the test, is composed of
4 very large, roughly globular, inflated chambers, which increase rapidly in size ;
the last chamber is strongly elongated radially and constitutes more than one-third
of the test ; on the ventral side the chambers are 4, globular, strongly inflated and
increase rapidly in size ; intercameral sutures on both sides straight, radial and
strongly incised ; spiral suture roughly angular, almost rectispiral and strongly
depressed ; umbilicus roughly quadrate, wide, deep and open ; aperture interio-
marginal, umbilical, with a thin lip of which remnants are still preserved ; wall
calcareous, perforate ; surface delicately pitted, with the raised parts between the
minute pits giving the surface a fine sugary texture.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter == Or 50 ain:
Minimum diameter = #0°36 mim.
Thickness == | 0-27) min.

REMARKS. Globigerina inaequispira is distinguished from other species by the
great difference in size between the successive whorls ; its large, triglobular, radially
elongate test ; its small, closely coiled early chambers, and large, loosely coiled,
rapidly increasing later ones ; its large, ovoid, radially elongate last chamber ; its
roughly angular, depressed spiral suture, and straight, radial, depressed intercameral
ones ; its distinctly lobate periphery, and finely pitted surface.

The forms described as G. inaequispira by both Loeblich & Tappan (1957a) and
Olsson (1960) are completely different from Subbotina’s original description and
figures, while that described by Hillebrandt (1962) lacks the radially elongate
terminal chamber characteristic of the species. The form described by Gartner &
Hay (1962) as G. inaequispira, may be G. stonei Weiss.

168 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

G. inaequispira is believed to have evolved from G. triloculinoides Plummer.
HypotyPe. P.45578.

HORIZON AND LOCALITy. Figured specimen, from sample No. 49, Gebel Owaina
section.

STRATIGRAPHICAL RANGE. Subbotina (1953) described G. inaequispira from the
“zone of conical Globorotalias ’’ of the northern Caucasus which she considered as
Lower to Middle Eocene. However, Berggren (1960d) considered this zone, on the
basis of its pelagic foraminiferal content, to indicate an Upper Paleocene-Lower
Eocene age.

In the Esna—Idfu region, G. inaequispiva appears in the lower part of the Middle
Paleocene G. angulata Zone. It continues as a rare to common form up to the
Upper Paleocene G. velascoensis Zone, fades out gradually in the top part of this
zone, dying out completely below the overlying G. wilcoxensis Zone.

«

Globigerina kozlowskii Brotzen & Pozaryska
(Pl. 15, figs. La—c, 2)
1961 Globigevina kozlowsku Brotzen & Pozaryska : 162-164, pls. 1-3.

DEscrRIPTION. Test small, coiled in a high trochospire, inflated ; dorsal side
broadly conical with a sharply pointed initial part, and strongly inflated later part ;
ventral side strongly inflated ; equatorial periphery broadly ovoid and distinctly
lobate, axial periphery rounded ; chambers on the dorsal side about 13 in number,
arranged in 3 sinistrally coiled whorls ; initial chambers extremely small, indistinct,
inflated, globigerine, increasing slowly in size up to the beginning of the last whorl,
where they start to enlarge so rapidly that the final whorl constitutes most of the test;
the last whorl is composed of 33, relatively large, roughly globular and strongly
inflated chambers ; on the ventral side the chambers are 34, relatively large, globular
and inflated ; sutures on the dorsal side curved, depressed in the early part, straight
and strongly incised between the later chambers ; on the ventral side they are
nearly straight, radial and strongly depressed; umbilicus very small, shallow and
nearly closed ; aperture interiomarginal umbilical ; wall calcareous, finely perforate ;
surface finely papillose.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter == 0:24) mim,
Minimum diameter == /0-20.1mm.
Thickness == Osos:

VARIATION. The main variation observed in the rare specimens of G. kozlowski
studied is in the occasional presence of minute, sutural openings and/or small, senile
chambers in some specimens, and in the size of the umbilicus which may sometimes
be closed.

REMARKS. G. kozlowskii is believed to have evolved from G. daubjergensis
Bronnimann in the uppermost Danian by the increase in the size of test, and the
development of a finely papillose surface instead of the finely spinose one character-

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 169

istic of G. daubjergensis. Transitional stages between these species are recorded in
the present study, and both their morphological features and stratigraphical ranges
strongly support this hypothesis.

Brotzen & Pozaryska, in their original description of the species, recorded a wide
range of variation, which included specimens with typical Globigerina characteristics,
and others with small, accessory, sutural apertures and/or an additional chamber
covering the umbilicus. These forms conform well with the three stages suggested
by Hofker (1960g, 7) in the development of G. daubjergensis Bronnimann which he had
described as the Globigerina, the Globigerinoides, and the Catapsydrax stages respec-
tively. However, as none of these stages was recorded by Broénnimann in his
original description, it is possible that Hofkers “‘ Globigerinoides and Catapsydrax
stages ’’ are actually the early representatives of G. kozlowskit.

These various, distinct stages in the same species population, recorded by Brotzen
& Pozaryska, made it difficult to decide with certainty the taxonomic position of
the species. However, these authors considered the wall structure of the test to be
the main criterion for classification, and as G. kozlowski1 was said to have the same
wall structure as typical Globigerina, it was considered to belong to Globigerina s.l.,
in spite of the accessory sutural apertures and the umbilical bulla.

The form here described as G. kozloskii is a typical Globigerina as it has neither the
accessory sutural apertures, nor the umbilical bulla. However, these minute sutural
apertures were observed in a few specimens in the same population. Until further
study of populations of both G. kozlowski and G. daubjergensis in their type areas
explains why these species apparently show the characters of more than one genus,
the present species is considered to belong to the genus Globigerina. It should be
noted that the holotype of G. kozlowskii was clearly shown to have accessory sutural
apertures. Retention of the species in Globigerina is further justified by the fact
that these accessory apertures appear to be different from those of typical Globi-
gerinoides species, and are only very feebly represented in the specimens from the
Esna—Idfu region and in topotype material kindly sent to the author by Dr. K.
Pozaryska. Forms with an additional chamber covering the umbilicus (umbilical
bulla) were not encountered in the samples studied, and were only recorded as rare
in the type area.

G. kozlowskw is possibly related to the similar, highly trochospirally coiled,
Paleocene forms such as G. chascanona Loeblich & Tappan, G. aquiensis Loeblich &
Tappan, and G. spiralis Bolli.

Gartner & Hay (1962) considered G. kozlowskii to be a junior synonym of G.
aquiensis Loeblich & Tappan, although the latter is clearly distinguished by its
roughly quadrangular chambers which increase slowly in size and are slightly
elongated in the direction of coiling, and by its wider umbilicus and spinose surface.

HypotyPe. P.45579.

HORIZON AND LOCALITY. Figured specimen, from sample No. 7 Gebel EI-
Kilabiya section.

STRATIGRAPHICAL RANGE. The species was first described from the Paleocene of
the “ Pamietowo’”’ well of northern Poland. Brotzen & Pozaryska (1961 : 156)

170 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

recorded the Maestrichtian in this well as unconformably overlain by a very thin
Danian section (I metre thick) which is conformably overlain successively by the
Paleocene and the Lower Eocene. Their Paleocene was divided into three successive
zones, lower, middle and upper. Apparently they considered the Danian separately
from the Paleocene, but described strata with a typical Upper Danian fauna as
lower Paleocene. This is proved by the occurrence of G. compressa (Plummer), a
typical Upper Danian index fossil, in what they described as Lower Paleocene (above
the Danian), and by the first appearance of G. angulata (White), a typical Danian—
Middle Paleocene boundary marker, in their so-called Middle Paleocene. Again they
described G. acuta Toulmin, an Upper Paleocene guide fossil, from their Lower
Eocene. According to the distribution of pelagic species in their section, both their
Danian and Lower Paleocene actually represent the Upper Danian, their middle and
upper Paleocene are in fact Middle Paleocene, and their Eocene is the Upper Paleo-
cene.

Brotzen & Pozaryska (1961) recorded this species as ranging from the uppermost
part of the Danian through the Middle Paleocene (as interpreted here) being most
typically developed in the latter. The species was stated to be rare higher in the
section where it shows all the peculiar variations, while below the uppermost
Danian the specimens were merely considered as variations of G. daubjergensis.

In the Esna—Idfu region G. kozlowski appears in the uppermost Danian with
forms transitional to G. daubjergensis Bronnimann ; it crosses the Danian—Middle
Paleocene boundary and occurs as a rare form in the lower part of the G. angulata
Zone.

Globigerina mckannai White
(Pl. 16, figs. 5a—c)

1928a Globigeyina mckannai White : 194, pl. 27, figs. 16a—c.

1947 Globorvotalia pentacamervata Subbotina : 128, pl. 7, figs. 12-17, pl. 9, figs. 24-26.

1950 Globigerina cretacea var. esnehensis Nakkady : 689, pl. 90, figs. 14-16.

1952b Globigerina gravellii Bronnimann : 12-13, pl. 1, figs. 16-18.

1953 Acavinina pentacamerata (Subbotina) Subbotina: 233, pl. 23, figs. 8a—c; pl. 24,

. figs. 1a—ge.

1955 Globorotalia pentacamervata Subbotina; Maslakova : 84, pl. 14, figs. 7-9.

1956 Globigerina dubia Egger var. lakiensis Haque : 174-175, pl. 4, figs. 2a-—c.

1956 Globovotalia pentacamerata Subbotina ; Sjutskaja : 103-104, pl. 4, figs. 6a—c.

1957) Globigerina gravelli Bronnimann ; Bolli: 72, pl. 16, figs. 1-3.

21957) Globorotalia mckannai (White) Bolli: 79, pl. 19, figs. 16-18.

19574 Globigevina mckannai White ; Loeblich & Tappan (pars) : 181-182, pl. 53, figs. 1a—2c ;
pl. 57, figs. 8a—c ; ? pl. 47, figs. 7a-c ; ? pl. 62, figs. 5a—7c.

1957a Globotalia stvabocella Loeblich & Tappan : 195, pl. 61, figs. 6a—c.

1958) Globigevina gravelli Bronnimann ; Hornibrook : 665, pl 2, figs. 21, 25.

1960 Globorotalia stvabocella Loeblich & Tappan ; Olsson : 48-49, pl. 10, figs. 10-12.

1960 Globorotalia mckannai (White) ; Bolli & Cita : 23-24, pl. 31, figs. 6a—c.

1960a Globigerina mckannai White ; Berggren (pars) : 68-71, pl. 9, figs. 3a—4c only ; non
pl. 1, figs. 4a—c ; pl. 9, figs. 2a—c ; pl. 10, figs. ta—c, text-fig. 7.

1960 Globorotalia pentacamerata Subbotina ; Said: 283, pl. 1, figs. 4a-c.

1961 Globorotalia pentacamerata Subbotina ; Said & Kerdany : 329, pl. I, figs. 15a—c.

‘VweveuU

vu

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 171

1962 Globorotalia (Acarinina) mckannai (White) ; Hillebrandt: 140-141, pl. 14, figs.
8a—10¢.
1962 Globoyvotalia (Acarinina) pentacamerata Subbotina ; Hillebrandt : 142, pl. 14, figs. 7a-c.

DESCRIPTION. Test large, coiled in a low trochospire ; dorsal side very slightly
raised, moderately inflated, ventral side highly raised and strongly inflated ; equa-
torial periphery subcircular, distinctly lobate ; axial periphery rounded ; chambers
on dorsal side 19, arranged in 3 dextrally coiled whorls ; the initial chambers are
small, globigerine, and are followed by slightly larger, roughly globular chambers
which increase moderately and regularly in size ; the last whorl is composed of 6
large, roughly globular chambers which are slightly elongated in the direction of
coiling and which increase regularly in size up to the fourth chamber and then become
gradually smaller ; on the ventral side the 6 roughly globular, strongly inflated
chambers increase moderately and regularly in size at first, but after the fourth
become smaller ; sutures on the dorsal side curved, depressed in the early part, very
slightly curved to almost straight, depressed in the later part ; on the ventral side the
sutures are almost straight, radial and strongly incised ; umbilicus wide, deep and
open ; aperture interiomarginal, umbilical ; wall calcareous, perforate ; surface
distinctly granular, papillose or even nodose, with the nodes tapering out in the form
of short, stout, spine-like projections especially along the periphery and around the
umbilicus.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter = 0-45 mm.
Minimum diameter = 0°34 mm.
Thickness = 0:28 mm. (across the middle part test)

REMARKS. White (1928) noticed that the aperture in G. mckannai extends from
the umbilicus approximately half way to the peripheral margin. This feature has
since made it difficult for authors to decide whether the species is a true Globigerina
or a Globorotalia.

Bolli (19570), followed by Bolli & Cita (1960), Hillebrandt (1962) and Gartner &
Hay (1962), removed this species to the genus Globorotalia, while Loeblich & Tappan
(1957a) and Berggren (1960a), emphasized the fact that it is a true Globigerina,
although the aperture in some specimens shows a tendency to extend to a somewhat
extraumbilical position. The present study substantiates these observations, and
specimens of G. mckannai with typical interiomarginal, umbilical apertures were
recorded in far greater numbers than forms with a slight tendency towards the devel-
opment of an extraumbilical aperture. Moreover, the forms described by Bolli
(19570) as Globorotalia mckannai (White) differ from the holotype in being smaller,
higher on the dorsal side and having a much narrower umbilicus. On the other
hand, Bolli (pl. 16, figs. 1-3, 10-12) described as G. gravelli Bronnimann and as a
transitional form between G. soldadoensis and G. gravelli, forms which are typically
G. mckannat.

Nakkady (1950) described as Globigerina cretacea var. esnehensis, a form which is
typically G. mckannai. Examination of the holotype of Nakkady (B.M.N.H.,

172 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

P.41762) confirms its identity with G. mckannaz, although the paratypes (B.M.N.H.,
P.41763) most probably belong to a different species.

Said & Kenawy (1956) quite unjustifiably removed Nakkady’s variety to the
genus Rugoglobigerina and raised it to specific rank. However, these authors did not
give any description, and their figures alone cannot be assigned to any known form.

Br6énnimann (19520), Bolli (1957b) and Hornibrook (1958) described as Globigerina
gravelli Brénniamnn, forms which conform well with G. mckannai White, and thus
G. gravellt is considered to be a junior synonym.

Loeblich & Tappan (1957a) followed by Olsson (1960) described as Globorotalia
strabocella Loeblich & Tappan, a form which may probably be an extreme variant of
G. mckannai or a transitional stage between it and Globorotalia hispidicidaris Loe-
blich & Tappan.

Globigerina mckannai White is believed to have evolved from Globigerina alan-
woodi sp. nov., by the development of the granular, spinose surface. On the other
hand, it is believed to have evolved into Globorotalia hispidicidaris Loeblich & Tappan
by the flattening of the dorsal side and the development of the angular truncate
chambers, subacute axial periphery, sharply angled umbilical shoulder and typical
extraumbilical-umbilical aperture. Again, it is not excluded that Globigerina
soldadoensis Broénnimann has also evolved from G. mckannat by the reduction in the
number of chambers and in the size of test.

Globigerina mckannai White is distinguished by its large, circular, moderately
inflated test ; its distinctly granular, nodose, spinose surface ; slightly raised dorsal
side and strongly inflated ventral side ; its numerous, subglobular, inflated chambers ;
short, depressed, radial sutures on both sides ; and wide, deep umbilicus.

HypotyPe. P.45580.

HORIZON AND LOCALITY. Figured specimen, from sample No. 51, Gebel Owaina
section.

STRATIGRAPHICAL RANGE. The species was first described from the Velasco
formation of Mexico which was wrongly considered by White as Upper Cretaceous.
Hay (1960) recorded it from the same formation, ranging throughout the Globorotalia
pseudomenardi and the Globorotalia velascoensis Zones which he considered as
Landenian.

Reliable records show that G. mckannat White is restricted to the Upper Paleocene
and the basal part of the Lower Eocene. All records of this species from rocks older
than Upper Paleocene (e.g. Bermudez 1961 ; Nakkady 1959 ; Said & Kenawy 1956)
are definitely erroneous, as are records from rocks younger than the Lower Eocene
(e.g. Bronnimann 19520).

In the Esna—Idfu region, G. mckanni White appears in the upper part of the Upper
Paleocene G. velascoensis Zone, the G. aequa/G. esnaensis Subzone. It floods the lower
and middle parts of this subzone, then fades out gradually towards the top. In the
overlying Lower Eocene, G. wilcoxensis Zone, a few forms were observed which only
differ from typical G. mckannaz in having fewer chambers and being much smaller in
size. They probably represent the last stage in the development of this species or a

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 173

transitional stage between it and a possible direct descendant, G. soldadoensis
Bronnimann.

Globigerina nodosa sp. nov.
(Pl. 15, figs. 6a—c)

Diacnosis. A Globigerina species with roughly triglobular, compressed test ;
nodose, spinose surface ; wide, deep umbilicus ; radial, depressed sutures ; and small
last chamber.

DeEscriPTION. Test small, coiled in a low trochospire, roughly triglobular,
compressed ; dorsal side weakly convex ; ventral side moderately inflated ; equa-
torial periphery roughly ovoid, distinctly lobate ; axial periphery rounded ; chambers
on the dorsal side appear to be 14 in number ; they are arranged in 3 sinistrally coiled
whorls, and increase rapidly in size in the early part and slowly later ; initial cham-
bers small, indistinct and almost masked by the surface rugosity ; the last whorl is
composed of 44 chambers (34 normal + I abortive) : with one exception these are
relatively large, roughly ovoid, moderately inflated and slightly compressed ; the
abortive chamber is relatively small, roughly ovoid and indistinct ; on the ventral
side the chambers are 44, roughly globular, slightly compressed and increase moder-
ately in size except for the small abortive chamber ; sutures on the dorsal side
curved, depressed in the early part, almost straight, radial and depressed later ; on
the ventral side they are straight, radial and strongly incised ; umbilicus wide, deep
and open ; aperture interiomarginal, umbilical ; wall calcareous, perforate ; surface
distinctly papillose or even nodose, with the nodes tapering out in the form of thick
stout, spine-like projections especially along the periphery and around the umbilicus.

DIMENSIONS OF HOLOTYPE.

Maximum diameter = 0-40 min.
Minimum diameter == (0°35 mim,
Thickness = 0-25 mm. (along the middle part of test)

REMARKS. This form is rather rare in the samples studied. However, it is quite
distinct from all known Globigerina species and is therefore described as new despite
its rarity.

Globigerina nodosa is distinguished from G. triloculinoides Plummer by its non-
reticulate, nodose, spinose surface ; its much wider umbilicus ; its compressed test ;
and by the lack of the well-developed apertural lip. It is distinguished from G.
inaequispiva Subbotina by its smaller, compressed, non-elongate test, its heavily
spinose surface and its much smaller last chamber. The forms described as Globi-
gerina inaequispira Subbotina, by Loeblich & Tappan (1957a) and by Olsson (1960)
are completely different from Subbotina’s original description and figures, but may
belong to the present species, although they are much more inflated. Similarly the
spinose forms described as G. trviloculinoides Plummer byShifflett (1948) belong to the
present species. Globigerina chascanona Loeblich & Tappan has a similar surface
texture but is much higher on the dorsal side, has more chambers and a much
narrower umblicus. Globigerina stone: Weiss has a more inflated test, an almost

174 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

rectlinear spiral suture, and its surface texture is not as rough as that of the present
species.

Globigerina nodosa sp. nov. probably evolved from G. chascanona Loeblich &
Tappan although no direct evidence was recorded.

HoLotTyPe. P.45581.
PARATYPES. P.45582.

HorRIZON AND LOocALITy. Holo- and paratypes, from sample No. 49, Gebel
Owaina section.

STRATIGRAPHICAL RANGE. Globigerina nodosa sp. nov. is a rather rare form
occuring only in the G. aequa/G. esnaensis Subzone of upper Upper Paleocene age.

Globigerina soldadoensis Bronnimann

1952b Globigerina soldadcensis Brénnimann : 9-11, pl. I, figs. 1-9.
1953 <Acayvinina interposita Subbotina : 231, pl. 23, figs. 6a—7c.
1957) Globigervina soldadoensis Bronnimann ; Bolli (pars) : 71, pl. 16, figs. 7-9, non figs. ro—12.

REMARKS. Globigerina soldadoensis Brénnimann is distinguished by its medium
sized to large, low trochospiral test ; its granular, heavily papillose, nodose surface ;
its 4-5 large roughly quadrangular chambers in the last whorl which are elongated in
the direction of coiling ; its straight, radial, strongly depressed sutures on both sides,
and its wide umbilicus.

G. soladoensis is very closely related to G. mckannai White from which it is believed
to have evolved by the reduction in size and in the number of chambers of test.
The form described by Bolli (1957), pl. 16, figs. 10-12) as transitional between
G. soladoensis and G. gravelli Bronnimann, is most probably G. mckannai White.
Bolli stated that G. soldadoensts is closely related to G. prinutiva Finlay ; however,
Bolh’s G. primutiva (pl. 15, figs. 6-8) is actually G. stoner Weiss, which may be related
to the present species although it is much smaller.

Gartner & Hay (1962) described as G. soldadoensis Bronnimann, a form which may
belong to G. esnaensis (Le Roy) as can be seen from their figures.

HypotyPe. P.45583.
HORIZON AND LOCALITY. Hypotype from sample No. 63, Gebel Owaina section.

STRATIGRAPHICAL RANGE. The species was first described from the Paleocene—
Eocene Lizard Springs, Soldado and Navet formations of Trinidad, and was recorded
from the same formations by Bolli (1957)). It was also recorded from the Paleocene
and Lower Eocene of the Caribbean region (Bermudez 1961) and from the “ zone of
conical Globorotalias ’’ of the northern Caucasus, (Subbotina 1953).

In the Esna—Idfu region, G. soldadoensis occurs as a rare form in the G. aequa/
G. esnaensis Subzone of uppermost Paleocene age, and continues in the overlying
Lower Eocene G. wilcoxensis Zone.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 175

Globigerina spiralis Bolli
(Pl. 16, figs. 2a—c)

19570 Globigerina spiralis Bolli: 70, pl. 16, figs. 16-18.
1960b Globigerina spivalis Bolli ; Bolli & Cita: 12, pl. 32, figs. 2a-c.
1962 Globigerina spivalis Bolli: Hillebrandt : 122, pl. 11, figs. 20a—b.

DEscriPTIon. Test medium sized, coiled in a relatively high trochospire ; dorsal
side highly convex ; ventral side moderately inflated ; equatorial periphery roughly
ovoid, lobate ; axial periphery rounded ; chambers on the dorsal side 22 in number,
increasing regularly in size and arranged in 4 dextrally coiled whorls ; initial chambers
small, inflated, globigerine, slightly compressed, increasing moderately in size and
followed by slightly less globular chambers which are moderately elongated in the
direction of coiling and increase slowly in size ; the last whorl is composed of 44
relatively large, crescentic to roughly quadrate chambers which are strongly elongated
in the direction of coiling and increase slowly in size ; the 44 chambers on the
ventral side are relatively large, roughly globular, and increase slowly in size ;
sutures on the dorsal side short, almost straight, radial and depressed ; on the
ventral side they are long, straight, radial and strongly incised ; umbilicus narrow,
open, filled with foreign material ; aperture interiomarginal, umbilical, partially
covered with the foreign material filling the umbilicus ; wall calcareous, perforate ;
surface smooth.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter ==) \O-e40mm.
Minimum diameter —) 0-20 nin:
Thickness == ©:26 Tent.

REMARKS. Globigerina spiralis Bolli is distinguished by its medium to small
sized, smooth, highly trochospirally coiled test ; its short, almost straight, depressed
dorsal sutures ; and long, straight, depressed, ventral ones ; its chambers which
increase slowly in size ; and its narrow umbilicus.

The species is morpholgically similar to both Globigerina edita Subbotina and
Globigerina compacta Hofker. An examination of the holotypes of these forms is
needed to establish their relationship.

Loeblich & Tappan (1957a) and Olsson (1960) described as G. spivalis Bolli, forms
with a rough spinose surface. These probably belong to Globigerina aquiensis
Loeblich & Tappan as suggested by their morphological features and stratigraphical
distribution.

G. spiralis Bolli probably evolved from G. arabica sp. nov. by a reduction in the
size of test and in the number of chambers in the last whorl, by the development of
more tightly coiled chambers which are strongly elongated in the direction of coiling,
a higher dorsal spire and a much narrower umbilicus. The morpholgical features
and stratigraphical distribution of these two species support this proposition,
although no direct evidence was recorded. On the other hand, G. spiralis probably
evolved into G. haynesi sp. nov. in the upper Danian time by a reduction in the number

176 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

of chambers, and in the height of the dorsal spire, by an increase in the rate of growth
in the last whorl and by the development of a delicately papillose surface.

HyYPotTyPe. P.45584.

HORIZON AND LOCALITY. Figured specimen, from sample No. 53, Gebel Owaina
section.

STRATIGRAPHICAL RANGE. Globigerina spiralis was first described from the
lower Lizard Springs formation of Trinidad, where it was found to be restricted to the
G. uncinata Zone. Bolli & Cita (1960a, b) recorded it from the Paleocene of the
Paderno d’Adda section of northern Italy, where they considered its range as
Danian. However the stratigraphical range of G. spiralis as interpreted from the
charts of Bolli (19570) and Bolli & Cita (1960a, b) is Upper Danian—lower Middle
Paleocene.

Hay (1960) recorded G. spiralis throughout the Upper Danian G. wncinata Subzone
of the Velasco formation of Mexico, and Hillebrandt (1962) recorded it throughout
the Upper Danian and the overlying Lower, Middle and Upper Paleocene of Austria.

In the Esna—Idfu region, G. spiralis appears as a rare to common form in the top
part of the Danian ; it increases gradually in number upwards in the section to the
basal part of the G. velascoensis Zone where it reaches its acme : it then fades out
gradually and dies out completely in the lower part of the G. aequa/G. esnaensis
Subzone (uppermost Paleocene).

Globigerina stonei Weiss
(Pl. 16, figs. 1a—d)

1949 Globigerina cf. pseudobulloides Plummer ; Cushman & Stone : 57, pl. 10, figs. 15a, b.
1955a@ Globigerina stonet Weiss : 18, pl. 5, figs. 16-21.

19550 Globigerina stonei Weiss ; Weiss : 308-309, pl. 2, figs. 1-3.

1957) Globigerina primitiva (Finlay) ; Bolli: 71, pl. 15, figs. 6-8.

DESCRIPTION. Test medium sized, coiled in a low trochospire ; dorsal side slightly
convex with the last chambers inflated and the early ones depressed in the form of a
sharply cut, slightly sunken, oblong mass ; ventral side strongly inflated ; equatorial
periphery roughly ovoid, distinctly lobate ; axial periphery rounded ; chambers on
the dorsal side about 9, arranged in 2 sinistrally coiled whorls, increasing moderately
in size in the early part and very rapidly later ; initial chambers very small, depressed,
tightly coiled and masked by the surface rugosity ; the last whorl is composed of 4
relatively large, subglobular chambers with almost straight inner margins and
distinctly curved outer ones ; the first two chambers in the last whorl are roughly
quadrangular, elongated in the direction of coiling and slightly inflated, while the last
two are roughly globular, much bigger in size and strongly inflated ; on the ventral
side the chambers are 4, globular, inflated and rapidly increasing in size ; sutures on
both sides straight, radial and strongly incised ; spiral suture angular, rectispiral and
strongly depressed ; umbilicus roughly rectangular in outline, relatively wide, deep
and open ; aperture interiomarginal, umbilical, a small narrow slit with a delicate

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 19/7)

apertural lip of which remnants are still preserved ; wall calcareous, perforate ;
surface heavily papillose or even nodose.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter ==) Or33. mame
Minimum diameter == | 0-25) mim.
Thickness = 0-25) toma.

REMARKS. Globigerina stonei is distinguished by its small to medium sized,
moderately inflated test ; its very small, tightly coiled, depressed early part, and
relatively large, strongly inflated chambers which increase rapidly in size in the last
whorl, and have almost straight, depressed, inner margins and distinctly curved
outer ones ; its radial, depressed sutures on both sides ; its angular, depressed spiral
suture, and its papillose or rather nodose surface.

Acarinina triplex Subbotina (1953, pl. 23) includes forms identical with both G.
stonei (figs. I, 3, 5) and G. velascoensis (figs. 2, 4). However, examination of the
holotypes is needed before using the name G. triplex for G. stonet.

Berggren (1960a) removed Acarinina triplex Subbotina to Globigerina as he noticed
that the aperture is interiomarginal, umbilical in position and sometimes extends
towards the periphery. He stated that he had compared his specimens of Globi-
gerina triplex (Subbotina) from the Lower Eocene of Denmark and northwestern
Germany with comparative material in the collection of Dr. N. Subbotina, Leningrad,
and found them to be identical. However, his figured forms (pl. 6, figs. 2a—3¢,
pl. 13, figs. ta—2c) differ from both Acarinina triplex Subbotina and G. stone Weiss,
in having a higher dorsal side, more spinose surface, and in lacking the straight
inner margins of the chambers and the angular spiral suture.

Subbotina (1953) also described as Globigerina pseudoeocaena var. trilobata, a form
which probably belongs to G. stonez, although it is much larger.

Bolli (1957)) described as Globigerina primitiva (Finlay), forms which most
probably belong to G. stonei Weiss, as can be seen from his figures. Globoquadrina
primitiva was first described by Finlay (1947) from the Middle Eocene of New
Zealand, but was removed to the genus Globigerina by Bronnimann (1952b). Exam-
ination of topotypes of Globoquadrina primitiva Finlay kindly sent to the present
author by Drs. N. de B. Hornibrook and G. Jenkins of the Geological Survey of New
Zealand, showed that it is quite distinct from the present species, although it has a
similarly rough surface, a straight, depressed spiral suture and a quadrate appearance.
In view of these morphological similarities, it is possible that G. stone evolved into
Globoquadrina primutiva in Lower Eocene time by the development of the character-
istic apertural flaps, the peculiar apertural face of the last chamber and the angularly
protruding ventral side. On the other hand, G. stonez is believed to have evolved
from G. velascoensis Cushman in Upper Paleocene time by the development of the
rough surface and non-appressed last chamber. Specimens of G. stonez with a finely
papillose surface are believed to be transitional to G. velascoensis, while those with
the heavily nodose surface are probably transitional to G. primitiva.

Gartner & Hay (1962) described as G. cf. G. inaequispiva Subbotina from the type

178 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

Ilerdian of Spain, forms which probably belong to G. stonez Weiss, as can be seen from
their description.

HypotyPe. P.45585.

HORIZON AND LOCALITY. Figured specimen, from sample No. 68, Gebel Owaina
section.

STRATIGRAPHICAL RANGE. The species was first described from the Upper Paleo-
cene, Pale Greda formation of northwestern Peru, and was previously recorded as
G. cf. pseudobulloides from the Lower Eocene Chacra formation of the same area
(Cushamn & Stone 1949). On his range chart, Weiss (19550) showed this species to
range throughout the Paleocene, Lower Eocene, and the lower part of the Middle
Eocene.

It was also recorded under the name G. primitiva (Finlay) from the Upper Paleoce-
ne—Lower Eocene of the Lizard Springs formation of Trinidad (Bolli, 19570), where
it was shown to range from the upper part of the G. psewdomenardu Zone to the upper
part of the G. avagonensis Zone.

In the Esna—Idfu region G. stonei Weiss appears in the uppermost Paleocene
G. aequa/G. esnaensis Subzone. It crosses the Paleocene—Lower Eocene boundary
and occurs abundantly in the overlying G. wilcoxensis Zone.

Globigerina triloculinoides Plummer
(Pl. 15, figs. 7a-c)

1926 Globigerina triloculinoides Plummer : 134-135, pl. 8, figs. toa—c.

1937) Globigervina triloculinoides Plummer ; Glaessner : 382, pl. 4, figs. 33a—c.

1940 Globigerina triloculinoides Plummer ; Cushman : 72, pl. 12, figs. 15a, b.

1941 Globigerina triloculinoides Plummer ; Toulmin : 607, pl. 82, fig. 3.

1942 Globigerina triloculinoides Plummer ; Cushman and Todd : 43, pl. 8, figs. 1, 2.

1943 Globigerina triloculinoides Plummer ; Beck : 609, pl. 108, figs. 2, 3.

1944 Globigevina triloculinoides Plummer ; Cooper: 353, pl. 54, figs. 12-13.

1952b Globigerina triloculinoides Plummer ; Brénnimann : 24-25, pl. 3, figs. 13-18.

1952b Globigerina hornibrookt Bronnimann : 15, pl. 2, figs. 4-6.

1952b Globigerina linaperta Finlay, Bronnimann : 16, pl. 2, figs. 7-9.

1952b Globigerina finlayi Brénnimann : 18, pl. 2, figs. 10-12.

1952b Globigerina stainfortht Bronnimann : 23, pl. 3, figs. 10-12.

1953 Globigerina tviloculinoides Plummer ; Subbotina: 82, pl. 11, figs. 15a-c, pl. 12, figs.
1a—2¢.

1953 Globigerina trivialis Subbotina : 64, pl. 4, figs. 4a—8c.

1955) Globigerina triloculinoides Plummer ; Weiss : 308, pl. 1, figs. 18, I9 ; non 20, 21.

1955) Globigerina pseudotriloba White ; Weiss : 308, pl. 1, figs. 11-13.

1955 Globigerina triloculinoides Plummer ; Dalbiez & Glintzboeckel (im Cuvillier et al.) :
534-536, text-figs. 2a—c.

1956 Globigerina triloculinoides Plummer ; Haynes : 99-100, pl. 17, figs. 15-15b, ? 11-110.

1956 Globigerina pseudotriloba White ; Said & Kenawy : 157, pl. 7, figs. 25a, b.

1957) Globigerina triloculinoides Plummer; Bolli (pars), 70, pl. 15, figs. 18-20, ? pl. 17,
figs. 25, 26.

1957) Globigerina linaperta Finlay ; Bolli: 70-71, pl. 15, figs. 15-17.

1957) Globigerina triangularis White ; Bolli: 71, pl. 15, figs. 12-14.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 179

1957a Globigerina tviloculinoides Plummer ; Loeblich & Tappan: 183, pl. 40, figs. 4a-—c ;
pl. 41, figs. 2a—c ; pl. 42, figs. 2a-c, pl. 43, figs. 5a—c, 8a—9c ; pl. 45, figs. 3a-c ; pl. 46,
figs. 1a—c ; pl. 47, figs. 2a—c ; pl. 52, figs. 3-7; pl. 56, figs. 8a—c ; pl. 62, figs. 3a—4c.

1957 Globigerina triloculinoides Plummer ; Troelsen : 129, pl. 30, figs. 4a—c, ? 3a-c.

1959 Globigerina triloculinoides Plummer ; Nakkady (pars) : 461, pl. 3, figs. 5a—c.

1960 Globigerina triloculinoides Plammer ; Olsson : 43, pl. 7, figs. 22-24.

1960 Globigerina triloculinoides Plummer ; Bolli & Cita: 13-14, pl. 31, figs. 1a—c.

1960g Globigerina triloculinoides Plummer ; Hofker (pars) : 76, figs. 26a—28c,? 24a-c ; non figs.
21da—C, 25a-C.

19602 Globigerina tviloculinoides Plummer ; Hofker (pars) : 128, pl. 3, figs. 2-4, ? fig. 1.

21961 Globigerina triloculinoides Plummer ; Said & Kerdany : 336, pl. 1, figs. 9a—c.
1962 Globigerina triloculinoides Plummer, Berggren : 86-88, pl. 14, figs. 1a—2b.
1962 Globigerina triloculinoides Plummer ; Hillebrandt : 119-120, pl. 11, figs. 1a—c.

DESCRIPTION. Test medium sized, triglobular, slightly compressed ; dorsal side
very slightly raised ; ventral side strongly inflated ; equatorial periphery roughly
ovoid, tripartite, distinctly lobate ; axial periphery rounded ; chambers on the dorsal
side 11, arranged in 3 dextrally coiled whorls ; the initial chambers are very small,
inflated, and increase slowly in size to the beginning of the last whorl, where the
chambers increase very rapidly in size ; the last whorl thus constituting most of the
test, and the last chamber almost half the test ; the last whorl is composed of 34
large, subglobular chambers ; on the ventral side the chambers are nearly 3},
globular and strongly inflated ; sutures on the dorsal side short, curved, depressed in
the early part, and long, depressed, very slightly curved in the later part ; on the
ventral side the sutures are strongly depressed, nearly straight and radial ; umbilicus
roughly triangular, narrow, shallow and open ; aperture interiomarginal, umbilical,
covered by a distinct, prominent lip ; wall calcareous, thin, finely perforate ; surface
coarsely pitted.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter = Ons Tit
Minimum diameter = 0°33 mm.
Thickness ==) 0-32 mm:

MAIN VARIATION.

1. Chambers 6-12, arranged in 2—-3 whorls, dextrally or sinistrally coiled (out of
610 specimens studied, 280 coiled sinistrally).

2. Chambers in the last whorl 3-4, moderately or rapidly increasing in size.

The surface reticulation varies from coarse to moderate.

4. The apertural flap varies in size, and the aperture in some specimens tends to
extend very slightly outside the umbilicus.

OO

Remarks. G. tviloculinoides is distinguished by its small, low trochospiral,
globular test ; its tripartite appearance ; distinctly pitted surface ; large, inflated
chambers of the last whorl ; narrow, shallow umbilicus ; and well-developed apertu-
ral flap. This species also exhibits a wide range of variation. Such variation,
which obviously falls within the limits of a single species population was used by
Bronnimann (1952)) as basis for erecting three new species: G. finlayi, G. horni-
brooki and G. stainfortm. He tried to distinguish between each of these forms and

180 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

G. triloculinoides, although, as can be seen from his descriptions and figures, they are
morphologically similar, occur in the same assemblage and have the same strati-
graphical distribution. Moreover Brénnimann (1952) : 16-17) described as G.
linaperta Finlay, forms which are actually G. triloculinoides Plummer. Globigerina
linaperta is a Middle Eocene form which may be a descendant of G. triloculinoides.

White (1928) described as G. bulloides d’Orbigny, G. pseudotriloba White, and G.
triangularis White, forms which most probably belong to G. triloculinoides Plummer.

Bolli (19570) studied samples from the same section of Brénnimann (19526) and
examined the holotypes of both White (1928) and Brénnimann (19520). He stated
that Globigerina finlay1, G. hornibrooki and G. stainfortht were found to be either
exceedingly scarce, or not sufficiently differentiated from existing species to warrant
separation. He considered G. finlayi Bronnimann a synonym of G. linaperta Finlay,
and G. hormibrookt Bronnimann a synonym of G. triangularis White, while he regarded
G. stainfortht Bronnimann as close to G. triloculinoides Plummer. However, Bolli’s
forms described as G. tviangularis White and G. linaperta Finlay are, most probably,
G. triloculinoides Plummer.

Loeblich & Tappan (1957a) considered G. stainforthi, G. hornibrooki, G. finlayi,
G. triangularis and G. pseudotriloba as synonyms of G. tviloculinoides Plummer. This
conclusion is here substantiated by the study of a large population of G. tviloculinotdes
from the Paleocene rocks of the Esna—Idfu region, which shows degrees of variation
easily covering the various forms previously described under different names in the
present synonymy.

Loeblich & Tappan also considered Globigerina velascoensis var. compressa White
as a synonym of G. tviloculinoides Plummer, in spite of the fact that Bolli (19570 ; 78)
had previously considered this species to belong to the genus Globorotalia where it
became a homonym of Globorotalia compressa (Plummer) ; hence he changed its
name to Globorotalia tortiva Boll. However, Loeblich & Tappan stated that Globo-
votalia toriva Bolli is completely different from Globigerina velascoensis var. compressa
White. An examination of the holotypes of White and of Bolli is essential to end
this conflict.

Subbotina (1953) described as Globigerina trivialis n.sp. and Globigerina eocaenica
Terquem var. eocaenica Terquem, forms which most probably belong to G. tviloculi-
noides Plummer, as mentioned by Berggren (1962).

Brotzen & Pozaryska (1961) erected a new genus Subbotina with Globigerina
trviloculinoides Plummer as type species. However, as stated above, Subbotina is
here considered a junior synonym of Globigerina d’Orbigny.

Hofker (1960g, 7) followed by Berggren (1962) suggested certain trends in the
evolutionary development of G. tviloculinoides. However, as the Lower and Middle
Danian are missing in the sections studied it was not possible to follow these trends.
Nevertheless, general tendencies towards a reduction in the size of the test and
towards an increase in surface reticulation were observed upwards in the section.

- HypotyPE. P.45586.

HoRIZON AND LocALiTy. Figured specimen, from sample No. 38, Gebel Owaina
section.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 181

STRATIGRAPHICAL RANGE. The species was first described from the basal part of
the upper Midway group of Texas, which, according to Loeblich & Tappan (1957a),
is of Upper Danian age. Plummer (1926 : 135) stated that the species is rare in the
lower Midway becoming most common in the basal part of the upper Midway, and
that it aids in marking the Cretaceous—Tertiary boundary, as no similar form has been
seen in the Cretaceous strata below. In spite of this early precise remark of Plum-
mer, many authors (e.g. Said & Kerdany 1961 ; Hofker 1960g, 7 ; Nakkady 1959 ;
Khalilov 1948, 1949 ; White, 1928) have recorded G. triloculinoides or its synonyms
from rocks of Maestrichtian age. Clearly, these authors confused G. tviloculinoides
with the superficially similar Maestrichtian Rugoglobigerina forms of the macrocephala
group.

Troelsen (1957) and Berggren (1960b, 1962) recorded G. triloculinoides as rare in the
lower part of the Middle Danian at its type locality in Denmark, and in southern
Scandinavia, becoming more common towards the Upper Danian Tylocidaris
vextlifera Zone ; they did not record it from the Lower Danian.

Berggren (1962 : 88) added that “it does not seem to occur in the Thanetian
glauconites above in southern Scandinavia (unless it be in subsurface sections in
Denmark), but its continued development elsewhere in more favourable facies is well
documented ”’.

Haynes (1955, 1956) recorded G. tviloculinoides from the type Thanetian of
England, and it was identified from recently studied Thanetian samples which were
kindly given to the present author by Dr. Haynes.

Bolli (19570) recorded G. trviloculinoides throughout the lower part of the Paleocene
lower Lizard Springs formation of Trinidad. However, Bolli’s G. triangularis White,
which he recorded throughout the whole Paleocene, is probably G. triloculinoides
Plummer.

Loeblich & Tappan (1957a), after a study of different Lower Tertiary sections
including the type locality of G. triloculinoides, showed that it ranges throughout the
whole Paleocene, but dies out completely before the basal Eocene.

Hay (1960) recorded G. triloculinoides throughout the whole Paleocene Velasco
formation of Mexico, it being most abundant in the Lower Paleocene (Danian).

Khalilov (1948, 1949), Subbotina (1953), Gans & Knipscheer (1956), Said (1960)
and Kupper (1961) extended the range of G. tviloculinoides to strata younger than the
Paleocene. These authors apparently confused G. triloculinoides with its younger
descendants.

In the Esna—Idfu region, G. tviloculinoides Plummer floods the whole Paleocene
section from the Upper Danian onwards (the Lower and Middle Danian being missing)
and dies out completely at the top of the Upper Paleocene Globorotalia velascoensis
Zone, and thus is considered one of the best Paleocene index fossils. All reliable
references record G. triloculinoides from Paleocene strata in various parts of the
world.

182 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

Globigerina triloculinoides parva subsp. nov.
(Pl. 15, figs. 4a-c)

Diacnosis. A Globigerina triloculinoides with much smaller, more tightly coiled,
compressed test, chambers increasing less rapidly in size and more strongly elongated
in direction of coiling.

DESCRIPTION. Test small, coiled in a low trochospire ; dorsal side weakly inflated
with the early chambers slightly raised above the level of the last whorl ; ventral side
moderately inflated ; equatorial periphery roughly ovoid, moderately lobate ; axial
periphery subrounded ; chambers on the dorsal side are not all clear, but appear to be
12 in number, arranged in 2} dextrally coiled whorls ; initial chambers are very
small, closely coiled, indistinct and almost masked by the surface pitting ; the last
whorl is composed of 34, roughly crescentic, narrow chambers which increase moder-
ately in size and are strongly elongated in the direction of coiling ; on the ventral
side the chambers are 33, relatively large, roughly globular, moderately inflated but
slightly compressed, especially the last one, and increase so rapidly in size that the
last chamber constitutes about half of the test ; sutures on the dorsal side, curved
depressed in the early part, almost straight, strongly incised later ; on the ventral
side they are straight, radial and strongly depressed ; umbilicus very small, narrow
and open, with the last chamber slightly pushed over it ; aperture interiomarginal,
umbilical, in the form of a long, narrow slit, with a narrow delicate flap ; wall
calcareous, perforate; surface densely pitted.

DIMENSIONS OF HOLOTYPE.

Maximum diameter = O° ai mim.
Minimum diameter SOLA 7/ isha.
Thickness = O25 im:

REMARKS. Globigerina triloculinoides parva is distinguished from G. ¢triloculin-
otdes Plummer, from which it is believed to have evolved, by its much smaller, less
lobulate, tightly coiled, slightly compressed test ; its roughly crescentic, narrow
chambers which are elongated in the direction of coiling, and which increase less
rapidly in size ; by its weakly raised early whorls and slightly compressed last
chamber.

Bronnimann (19520) described as G. hornibrooki n.sp., a form which appears to be
closely related to the present subspecies. However, Loeblich & Tappan (1957a)
considered G. hornibrooki to be a junior synonym of G. tviloculinoides Plummer, while
Bolli (19570) considered it to be a junior synonym of G. tviangularis White. Indeed
G. triangularis White appears to be closely related to G. triloculinoides parva although
it is much larger, but White’s description is incomplete and the form figured by Bolli
who had examined White’s holotype, is most probably G. triloculinoides Plummer.

Khaliloy (1956) described as G. triloculinoides var. nanus, a form which only
differs from typical G. triloculinoides Plummer in its smaller size and slightly deepened
septal sutures. Khalilov’s form should probably be included within G. triloculinoides
Plummer, and is believed to be transitional to G. trviloculinoides parva. It is distin-

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 183

guished from the present subspecies by its triglobular test and strongly inflated last
chamber, characteristic of typical G. triloculinoides Plummer.

HoLotyPe. P.45587.
PARATYPES. P.45588.

HoRIzZON AND LOCALITY. Holo- and paratypes, from sample No. 53, Gebel
Owaina section.

STRATIGRAPHICAL RANGE. Globigerina triloculinoides parva appears as a rare form
in the Upper Danian G. compressa/G. daubjergensis Zone and continues as a common
form throughout the Middle and Upper Paleocene. It reaches its acme in the upper
part of the G. velascoensis Zone, and then fades out gradually, dying out completely
at the top of this zone. As the Lower and Middle Danian are missing in the sections
studied, it is not known whether this subspecies accompanies the central form in the
Lower and Middle Danian or not.

Globigerina velascoensis Cushman
(Pl. 16, figs. 3a—-d)

1925 Globigerina velascoensis Cushman : 19, pl. 3, figs. 6a—c.

1926b Globigerina velascoensis Cushman ; Cushman : 605, pl. 20, fig. 21.

1928 Globigerina velascoensis Cushman ; White : 196, pl. 28, figs. 2a, b.

1953 Acarinina triplex Subbotina : 230, pl. 23, figs. 2a—c, 4a—c only.

19570 Globigerina velascoensis Cushman ; Bolli: 71, pl. 15, figs. 9-11.

?1960b Globigerina velascoensis Cushman ; Bolli & Cita : 14-15, pl. 32, figs. 8a—c.
1962 Globigerina velascoensis Cushman ; Hillebrandt : 120-121, pl. 11, figs. 4a, b.

DESCRIPTION. Test medium sized, coiled in a low trochospire, moderately
inflated, more so on the ventral than on the dorsal side ; equatorial periphery
roughly ovoid, distinctly lobate ; axial periphery rounded with the last chamber
slightly compressed laterally ; chambers on the dorsal side about 11, tightly arranged
in 24 sinistrally coiled whorls, increasing moderately in size in the early part and very
rapidly later ; the proloculus appears to be relatively large, globular, inflated, and is
followed by crescentic chambers which become roughly quadrangular, and elongate
towards the beginning of the final whorl ; the last whorl is composed of 33, roughly
ovoid, angular chambers, with fairly straight inner margins and distinctly curved
outer ones ; the last chamber constitutes about 4 of the test ; on the ventral side the
chambers are 34, roughly globular, strongly inflated and increase very rapidly in
size ; sutures on the dorsal side curved, depressed in the early part, almost straight
and depressed later ; on the ventral side they are almost straight, radial and strongly
depressed ; the spiral suture is curved, depressed in the early part, straight, angular
(rectispiral) and strongly depressed later ; umbilicus small, narrow and open ;
aperture interiomarginal umbilical, a long narrow slit with a delicate apertural lip of
which remnants are still preserved ; wall calcareous, perforate ; surface delicately
pitted.

184 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter = 039 mm.
Minimum diameter = 0°25 mam,
Thickness =" 0°27 Tim.

REMARKS. The holotype of G. velascoensis was described as being much compres-
sed with the sides very nearly parallel, in contrast to the strongly inflated, biconvex
forms here described, but Bolli (1957) : 71) stated that Cushman’s holotype is a
poorly preserved and somewhat deformed specimen. Consequently, it would have
been quite justifiable to ignore Cushman’s deformed holotype, and give the strongly
inflated forms described here a new name. However, as Cushman’s deformed holo-
type still shows clearly the main characteristics of G. velascoensis as described by
White (1928), Bolli (1957), and as shown in the present study, Cushman’s name
is here retained.

Subbotina (1953) described as Acarinina triplex forms which include both Globi-
gerina velascoensis Cushman and G. stone: Weiss.

Specimens of G. velascoensis from the Esna—Idfu region conform well with those of
White (1928) and of Bolli (19570), although the latter described his forms as having
a smooth surface and a slightly concave dorsal side.

The species is distinguished by its medium sized, inflated test, its strongly appres-
sed last chamber, its angular, depressed spiral suture and its 34-4 chambers in the
last whorl which increase rapidly in size. It is also characterized by the shape of its
later chambers which are roughly oblong, with straight inner margins and distinctly
curved outer ones.

Globigerina velascoensis was considered by Bolli (1957b) to have evolved from
G. triangularis White, a probable junior synonym of G. ¢tviloculinoides Plummer,
although no direct evidence was recorded. However, as G. haynesi n.sp. was clearly
observed to have a tendency towards the development of an angular, depressed
spiral suture, a tightly coiled test, almost straight inner margins of the chambers in
the last whorl and a finely papillose surface, it may represent the ancestral stock from
which G. velascoensis evolved. The stratigraphical ranges of the two species are in
favour of this proposition, and forms of G. haynesi with a flatter dorsal side are
considered to be transitional to G. velascoensis. On the other hand, G. velascoensis is
believed to have evolved into G. stonet Weiss by the development of the heavily
nodose or even spinose surface, the chambers which increase more rapidly in size, the
wider umbilicus and the less appressed last chamber. Transitional stages between
these two species were recorded and their stratigraphical distribution also strongly
substantiates this proposition.

HypotyPe. P.45589.

HoRIZON AND LOCALITY. Figured specimen, from sample No. 51, Gebel Owaina
section.

STRATIGRAPHICAL RANGE. The species was first described by Cushman (1925)
from the Velasco formation of Mexico where its stratigraphical distribution was
wrongly stated as Upper Cretaceous. It was also recorded from the same formation

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 185

by Cushman (1926), White (1928), and Hay (1960) where the latter showed it to
range from the Upper Danian G. wncinata Subzone throughout the whole of the over-
lying Landenian, where it becomes a flood form.

Bolli (19570) recorded G. velascoensis throughout the G. pseudomenardu — G. velasco-
ensis Zones of the lower Lizard Springs formation, Trinidad, which are here consider-
ed as Upper Paleocene. It was again recorded from the same zones in the Paderno
d’Adda section of northern Italy, which Bolli & Cita (1960a, b) considered to be
Upper Montian—Thanetian.

Globigerina velascoensis was also recorded from the Paleocene of Guatemala
(Bermudez 1961) and from the Paleocene of Austria (Montian—Landenian—Ilerdian)
(Hillebrandt 1962).

Reliable references show that G. velascoensis ranges only through the Upper
Paleocene. All records of this species from rocks younger than Upper Paleocene,
(e.g. Emiliani 1954, who recorded it from the Lower Oligocene of Italy) are either
erroneous or of reworked specimens, while all records from older strata (e.g. Hay
1960 and Hillebrandt 1962) are most probably confused with apparently similar
Globigerina species.

In the Esna—Idfu region, G. velascoensis appears in the basal part of the Upper
Palecocene Globorotalia velascoensis Zone, and continues as a rare to common form
to the upper part of this zone, where it dies out completely.

Family GLOBOROTALIIDAE Cushman 1927
Subfamily GLOBOROTALIINAE Cushman 1927
Genus GLOBOROTALIA Cushman 1927

TYPE SPECIES. Pulvinulina menardw (d’Orbigny) var. tumida Brady 1877.

1927). Globorotalia Cushman : 91 (Type species : Puluvinulina menardii (d’Orbigny) var. tumida
Brady 1877).

1949 Globorotalia (Globorotalia) Cushman & Bermudez: 28 (Type species: Pulvinulina
menarvdu (d’Orbigny) var. tumida Brady 1877).

1949 Globorotalia (Tvuncorotalia) Cushman & Bermudez : 35 (Type species : Rotalina trun-
catulinoides d’Orbigny 1839).

1949 Globorvotalia (Turborotalia) Cushman & Bermudez: 42 (Type species: Globorotalia
centvalis Cushman & Bermudez 1937).

1953 Acarinina Subbotina : 219 (Type species : Acarinina acayvinata Subbotina 1953).

1957 Planorotalia Morozova : 1110 (Type species : Planulina membranacea Ehrenberg 1854).

1957 Planorotalites Morozova : 1112 (Type species : Globorotalia pseudoscitula Glaessner 1937).

1958 Globorotalia (Astrorotalia) Turnovsky : 81 [Type species: G. (A.) stellaria Turnovsky
1958].

1959 Globigervina (Eoglobigerina) Morozova : 1115 [Type species : Globigerina (Eoglobigerina)
eobulloides Morozova, 1959].

EMENDED DIAGNOSIS. Test free, trochospirally coiled, with relatively wide
range of variation in size and shape, globigerine, biconvex or planoconvex ; dorsal

side evolute, flat or inflated ; ventral side umbilicate, moderately or strongly pro-
truding ; plane of coiling either horizontal or curved ; equatorial periphery

186 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

rounded, ovoid, or even angular, weakly or strongly lobate, with or without a single
marginal keel which can either be weakly or strongly developed, papillose, nodose,
spinose or only thickened and limbate ; axial periphery rounded, subrounded,
subacute or acute ; chambers arranged in 2—4 whorls, dextrally or sinistrally coiled ;
all chambers seen on dorsal side, only those of last whorl seen on ventral side ;
initial chambers generally globular, moderately or strongly inflated ; later ones
variable in shape, globular, ovate, lenticular, angular rhomboid or angular conical ;
sutures on dorsal side straight or curved, raised or depressed, sometimes thickened,
limbate or beaded ; on ventral side sutures generally radial or slightly curved,
depressed ; umbilicus varying in shape and size, very small or large, with or without
everted umbilical collar and/or high, decorated umbilical shoulders, but always
present and open ; aperture interiomarginal, extraumbilical-umbilical, rounded,
ovoid or slit-like, sometimes bordered by a lip varying from a narrow rim to a broad
flap ; wall calcareous perforate, except for the imperforate keel (where present) ;
surface smooth or roughened, papillose, hispid or even spinose.

Discussion. Cushman (1927b) described Globorotalia as a new genus with
Pulvinulina menardi (d’Orbigny) var. tumida Brady as the type species. Marie
(1941) considered Globorotalia Cushman to have a single terminal aperture, and thus
included forms of Globorotalia in which the apertures of the previous chambers
remain open into the umbilicus, together with Globotruncana Cushman within his
genus Rosalinella (a junior synonym of Globotruncana) despite the marked difference
in their apertural characters.

Cushman & Bermudez (1949) divided Globorotalia largely on the basis of chamber
shape into three subgenera, Globorotalia (Globorotalia), G. (Tvuncorotalia) and G.
(Turborotalia). The first subgenus was characterized by its biconvex, compressed
test, angular periphery and small umbilicus ; the second was distinguished by its
planoconvex, strongly umbilico-convex test, angular periphery, and peculiarly-
shaped apertural face of the last chamber ; the third was separated on the basis of
its globular test, rounded periphery and absence of a definite umbilicus. This
division of Globorotalia was either partly or completely accepted by various authors,
in spite of the fact that chamber shape and the dimension of the umbilicus are
characters of specific rather than generic or subgeneric importance, and that all
gradations between one extreme and the other have been recorded. Banner & Blow
(1959) considered Tvuncorotalia to be a junior synonym of Globorotalia and Turboro-
talia to be a subgenus of the latter. They distinguished Globorotalia (Globorotalia)
from Globorotalia (Turborotalia) by the fact that the former has an imperforate
peripheral carina, at least in part. Loeblich & Tappan (1964) raised Turborotalia
to generic rank, distinguishing it mainly on the basis of its non-carinate periphery.
However, it can be demonstrated that representatives of Globorotalia with a rounded,
non-carinate periphery evolve gradually into truncated, non-carinate forms, with an
acute periphery. These latter, in turn, evolve into sharply keeled Globorotalia
through various stages with incipient or partially developed keels. All gradations
between each of these forms and the following are documented and show clearly that
the division of the present genus into two genera or subgenera (Globorotalia and

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 187

Turborotalia) on the basis of the presence or absence of keelis not practicable. Species
with an acute, non-carinate periphery such as Globorotalia aequa Cushman & Renz,
G. angulata angulata (White), G. whiter Weiss, G. wilcoxensis Cushman & Ponton,
G. apanthesma Loeblich & Tappan, G. hispidicidaris Loeblich & Tappan, G. pusilla
pusilla Bolli and G. uncinata uncinata Bolli neither fit Turborotalia Cushman &
Bermudez nor Globorotalia sensu Banner & Blow (1959) and Loeblich & Tappan
(1964).

Thus, in the present study, the genus Globorotalia is considered to include forms
with a rounded non-carinate periphery, forms with an acute non-carinate periphery,
and others with a marginal keel. The recorded transitional stages between these
forms exclude the possibility of splitting the genus into two genera or subgenera, and
proves Turborotalia and Truncorotalia to be junior synonyms of Globorotalia. How-
ever, while Globotruncana is differentiated from Rugoglobigerina on the basis of the
presence of the keel or keels, no such gradation was recorded between them, although
Gandolfi (1955) stated that Globotruncana undergoes a process of globigerinization
to evolve into Rugoglobigerina. Again, the splitting of Hedbergella from Praeglobo-
truncana is based only on the presence of a partially or completely developed keel
in the latter genus. However, it is not excluded that non-carinate forms have
evolved imperceptibly into carinate ones.

Subbotina (1953) described Acarinina as a new genus distinguished by its Globi-
gerina-like appearance, which she described as being “ well-defined in angular
Acarininas and better defined in rounded ones’. She also mentioned that in addi-
tion to the angular and rounded Acarininas, “... there are the intermediate species
of Acarininas, which are a transitional group between Globotruncana and Acarinina”’’.
In spite of this confusion, her description is identical with that of Cushman &
Bermudez (1949) for Turborotalia, which is here considered to be a junior synonym of
Globorotalia Cushman 1927, and hence is Acarinina Subbotina. Similarly, Planoro-
talia Morozova 1957 ; Planorotalites Morozova 1957, Globorotalia (Astrorotalia)
Turnovsky 1958, and Globigerina (Eoglobigerina) Morozova 1959 are all junior syno-
nyms of Globorotalia Cushman 1927, as their type species conform well with Globoro-
talia as defined by Cushman (1927) and emended in the present study. Loeblich &
Tappan (1964) considered Globigerina (Eoglobigerina) Morozova to be a junior
synonym of Globorotaloides Bollitg57. The latter genus, as described by Bolli (1957)
and emended by Loeblich & Tappan (1964) includes forms transitional between
Globigerina and Globorotalia and should be included in part in their synonymy.
However, the fact that Bolli mentioned that the ultimate chamber normally has a
single aperture, though multiple ones may occur, does not permit its inclusion in the
synonymy of either Globorotalia or Globigerina for the time being, although none of
his figures showed these multiple apertures.

Globorotalia is distinguished from Globigerina d’Orbigny by its extraumbilical
aperture, the occasional flattening of its chambers, and the occasional presence of a
marginal keel and an umbilical everted collar or shoulder. It is distinguished from
Rugoglobigerina Bronniman by the above-mentioned characters, as well as by the
lack of an umbilical cover-plate and of surface meridional costae. It differs from

188 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

both Hedbergella Bronnimann and Brown and Praeglobotruncana Bermudez in
lacking umbilical portici ; furthermore Hedbergella has no keel, and the keel in
Praeglobotruncana is much weaker than in sharply keeled Globorotalia. It is distin-
guished from both Globotruncana Cushman and Abathomphalus Bolli, Loeblich &
Tappan by the absence of the umbilical cover-plate, by the occasional presence of
a single keel, by its extraumbilical aperture (that of Globotruncana is umbilical), and
by the fact that it always has a definite open umbilicus however small, whereas the
umbilicus in Abathomphalus is much reduced and is covered by the tegellum.

EVOLUTIONARY DEVELOPMENT OF GLOBOROTALIA

Very little is known about the origin of Globorotalia because of the marked faunal
break between the Maestrichtian and the Danian. However, it is possible that the
genus evolved from the youngest representatives of Hedbergella (which disappeared
completely at the top of the Maestrichtian) by the reduction of the apertural flaps
(the umbilical portici) and by the development of the simple umbilicus. Globorotalia,
in its turn, evolved into Globigerina by the confinement of the aperture to an interio-
marginal, umbilical position. On the other hand, it is not impossible that Rugoglo-
bigerina evolved into Globigerina by the loss of the tegilla and the surface meridional
costellae, and that the latter evolved into Globorotalia by the development of the
extraumbilical, umbilical aperture. Whatever the origin of Globorotalia, its earliest
representatives are known to have a rounded, non-carinate test, which is generally
smooth surfaced. At stratigraphically higher levels, these rounded, smooth forms
show two major tendencies in their evolution :

1. A general tendency towards the flattening of the dorsal side, followed by the
gradual development of a marginal keel through various intermediate
stages.

2. A general tendency towards increasing the surface rugosity.

These two tendencies develop either separately or in combination, with the result
that the early Paleocene rounded, smooth globorotalias evolve gradually into forms
with truncated, non-keeled and/or slightly rougher tests which in turn, evolve into
the truncated, sharply-keeled and/or very rugose forms which characterize the
Upper Paleocene in various parts of the world. In the Lower Eocene, a new tendency
towards reduction in the size of test and increase in the surface rugosity is observed.
The result is that most of the Lower Eocene forms are smaller than the Paleocene
ones and/or have an extremely rough surface. These tendencies are clearly docu-
mented in the present study, and are demonstrated by several lineages, summarized
on Text-fig. 15.

Globorotalia acuta Toulmin
(Pl. 19, figs. 5a-c ; Pl. 20, figs. 1a—d)

1941 Globorotalia wilcoxensis Cushman & Ponton var. acuta Toulmin : 608, pl. 82, figs. 6-8.

1942 Globorotalia wilcovensis Cushman & Ponton var. acuta Toulmin ; Cushman & Renz :
12, pl. 3, figs. 2a-c.

19574 Globorotalia acuta Toulmin ; Loeblich & Tappan : 185-186, pl. 47, figs. 5a—c; pl. 55,
figs. 4a—5c ; pl. 58, figs. 5a—c.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 189

DESCRIPTION. (Specimen, Pl. 20, figs. ra-d.) Test medium-sized, planoconvex,
umbilico-convex, coiled in a very low trochospire ; dorsal side flat ; ventral side
distinctly protruding with a high umbilical shoulder and a rough, beaded umbilical
flange ; equatorial periphery roughly ovoid, weakly lobate, with a well-developed,
beaded keel ; axial periphery sharply acute ; the chambers on the dorsal side increase
rapidly in size ; they are about Ir in number, arranged in 2 sinistrally coiled
whorls ; the initial chambers are small, indistinct and almost masked by the surface
rugosity ; the last whorl is composed of 5 relatively large, roughly crescentic
chambers ; those on the ventral side are large, strongly angular conical and increase
rapidly in size ; their distal ends taper out and are crowned with a papillose
umbilical collar ; sutures on the dorsal side distinct, flush with the surface, oblique
and directed sharply backwards ; on the ventral side they are radial and strongly
incised ; umbilicus conical in shape, very wide at its top, narrow at the bottom, deep,
open and surrounded by a heavily beaded collar ; aperture interiomarginal, extra-
umbilical-umbilical, a long, wide arch extending to the periphery with a distinctly
developed apertural lip ; wall calcareous, perforate ; surface delicately papillose on
the dorsal side, more distinctly so on the ventral, and heavily papillose in the
umbilical collar and the marginal keel, with the papillae sometimes tapering out in
the form of spine-like projections.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter = | 0:44 mm.
Minimum diameter = O-S2emnimn:
Thickness = 0-25 mm.

REMARKS. The species was first described by Toulmin (1941) as a variety of
G. wilcoxensis Cushman & Ponton. Cushman & Bermudez (1949) considered this
form to belong to their subgenus Tvuncorotalia but retained it as a variety of G.
wilcoxensis.

Grimsdale (1951), followed by Hamilton (1953) and Graham & Classen (1955)
realizing that Toulmin’s variety is unrelated to G. wilcoxensis, but is morphologically
very similar to G. velascoensis (Cushman), changed its name to G. velascoensis
(Cushman) var. acuta Toulmin.

Haynes (1955, 1956) described as G. velascoensis (Cushman) aff. var. acuta Toulmin,
a form which is actually a reworked Upper Cretaceous Globotruncana species redeposi-
ted in the type Thanetian.

Dalbiez & Glintzboeckel (1955) raised Toulmin’s variety to specific rank and inclu-
ded it in Truncorotalia, a junior synonym of Globorotalia, as mentioned above.

Bolli (1957) and Hillebrandt (1962) considered Toulmin’s form to be a junior
synonym of G. velascoensis (Cushman), while Loeblich & Tappan (1957a) considered
the two species separately. In the Esna-Idfu region, where the two forms are
extremely well developed, their morphological characters warrant their separation.

Globorotalia acuta Toulmin is distinguished from G. velascoensis velascoensis
(Cushman) by its much smaller test, tighter coiling, chambers which increase more
rapidly in size and are fewer both in total number and in number in the last whorl :

190 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

by its rough surface, less pronounced marginal keel and umbilical collar, flush dorsal
sutures and much wider, inward tapering, funnel shaped umbilicus.

Berggren (1960d : 99) considered G. lensiformis Subbotina to be a junior synonym
of G. acuta Toulmin. However, the present study showed that the two forms are
quite distinct. G. lensiformis is distinguished by its extremely narrow umbilicus,
while G. acuta has an extremely wide umbilicus with a large, beaded umbilical collar.

Aubert (1963) described as G. acuta Toulmin, from the Paleocene of Western
Morocco, a form which most probably belongs to G. velascoensis parva Rey.

Globorotalia acuta has possibly evolved from G. angulata angulata (White) or G.
angulata abundocamerata Boll, although no direct evidence was recorded.

HypotyPes. P.45590-o1.

HoRIZON AND LOCALITY. Figured specimens, from sample No. 40, Gebel Owaina
section.

STRATIGRAPHICAL RANGE. The species was first described by Toulmin (1941) from
the Salt Mountain limestones of Alabama which he considered as Lower Eocene, but
was proved by Loeblich & Tappan (1957a) to be of Upper Paleocene age. It was
also recorded from the Paleocene Soldado formation of Trinidad (Cushman & Renz
1942) ; from the various Paleocene formations of the Gulf and Atlantic Coastal
Plains (Cushman 1944 ; Shifflett 1948 and Loeblich & Tappan 1957 a, b) ; from the
Paleocene of Cuba (Cushman & Bermudez 1948, 1949 ; Bermudez 1950) ; from what
was considered as Lower Eocene of Mexico, Carribbean region and the Middle East
(Grimsdale 1951) ; from the Mid-Pacific seamounts (Hamilton 1953) ; from the
Cretaceous—Tertiary passage beds of Morocco (Rey and Lys in Cuvillier e¢ al., 1955) ;
from the so-called Montian—Thanetian of Algeria (Magné & Sigal, zbzd.) ; from the
Truncorotalia Zone of the Cretaceous—Tertiary passage beds of Tunisia (Dalbiez &
Glintzboeckel, zbid.) ; from the Paleocene of Lebanon (Lys & Renouard, 7bid.) ;
from the Velasco formation of Mexico (Loeblich & Tappan, 1957a, b ; Bermudez 1961)
and from the Upper Paleocene Jicara formation of Puerto Rico (Pessagno 1960).

In the Esna—Idfu region G. acuta floods the G. velascoensis Zone of Upper Paleocene
age, starting at its base and dying out completely at its top.

Globorotalia aequa Cushman & Renz
(PI. 21, figs. 4a—c)

1942 Globorotalia crvassata (Cushman) var. aequa Cushman & Renz : 12, pl. 3, figs. 3a—-c.

1946 Globorotalia lacevti Cushman & Renz : 47, pl. 8, figs. 11-12.

1947 Globorotalia cyassata (Cushman) ; Subbotina : 119-121, pl. 5, figs. 31-33, pl. 9, figs.
15-17.

1953 Globorotalia crassata (Cushman) ; Subbotina (pars) : 211, pl. 17, figs. 11a—12¢, ? figs.
7a-10c, non figs. 13a-c.

1955 Tvuncorotalia crassata var. aeqgua (Cushman & Renz) ; Dalbiez & Glintzboeckel (in
Cuvillier et al., 1955) : 533, pl. 2, figs. 9a—c.

1956 Globorotalia praenartanensis Sjutskaya : 98, pl. 3, figs. 5a-—c.

1957) Globorotalia aequa Cushman & Renz; Bolli (pars) : 74-75, pl. 17, figs. 1-3, ? pl. 18,
figs. 13-15.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT IQI

1957 Globovotalia cvassata var. aequa Cushman & Renz; Sacal & Debourle: 64, pl. 29,
figs. 10-12.
1960b Globorotalia aequa Cushman & Renz ; Bolli & Cita : 17-18, pl. 31, figs. 5a—c.
? 1962 Globorotalia aequa Cushman & Renz ; Gartner & Hay : 560-561, pl. 2, figs. 1a—2b.

DeEscripTion. Test large, coiled in a very low trochospire, strongly umbilico-
convex ; dorsal side almost flat, slightly imbricate, with the early whorls slightly
more elevated than the last one ; ventral side highly convex and strongly protruding ;
equatorial periphery ovoid, distinctly lobate and roughly serrate ; axial periphery
acute with the marginal serrations simulating a faintly developed nodose keel ;
chambers on the dorsal side 11, arranged in 3 dextrally coiled whorls ; initial cham-
bers very small, slightly inflated, globigerine, increasing very slowly in size, and
masked by the surface rugosity ; the last whorl is composed of 34, large, crescentic
chambers which increase very rapidly in size, the last chamber thus constituting
about one third of the test ; on the ventral side the chambers are 33, large, strongly
inflated and distinctly protruding ; sutures on the dorsal side strongly curved,
slightly depressed ; on the ventral side they are radial, strongly depressed ; umbilicus
roughly rectangular, narrow, deep and open ; aperture interiomarginal, extra-
umbilical-umbilical, a long, roughly crescentic, wide arch, extending to the periphery ;
wall calcareous, perforate ; surface highly roughened by long stout, spine-like
projections or granules, the roughness decreasing gradually towards the last chamber.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter = 0-48 mm:
Minimum diameter = 0°34 mm.
Thickness = 0:30 mm.

MAIN VARIATION.

I. Chambers 9-12, arranged in 23-3 whorls predominantly dextrally coiled
(of 154 specimens chosen at random, 3 coiled sinistrally).

2. The last whorl is composed of 3-4 chambers (usually 34) which increase very
rapidly in size.

REMARKS. Globorotalia aequa was first described by Cushman & Renz (1942) as
a variety of G. crassata (Cushman) ; these authors briefly stated “‘ Variety differing
from the typical in the much smoother surface, and the chambers, especially the
later ones, broader and more arcuate’’. However, from their figures, it is clearly
seen that the form has a rough surface and a distinctly spinose periphery.

Bolli (19570 : 75) stated that ‘‘ No close morphologic or stratigraphic connection
is evident between Globorotalia aequa Cushman & Renz and the coarsely spinose
G. crassata (Cushman) from the middle to upper Eocene’, and thus he raised this
variety of Cushman & Renz to specific rank. He added, ‘‘ A comparison of the
holotypes of G. aequa and G. lacerti Cushman & Renz clearly indicates that the latter
is a junior synonym’’. The author is in entire agreement with Bolli’s observations,
although it has to be clearly stated that G. aequa is characterized by its rough,
coarsely spinose, nodose surface, contrary to the impression given by Bolli’s state-
ment and by that of Cushman & Rentz (1942). Again G. acqua is charaterized by its

192 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

curved, depressed, dorsal sutures, which were vaguely described by Renz (1951) as
rather well-pronounced dorsal sutures.

Nakkady (1951a) described as Globorotalia colligera (Schwager), forms which
most probably belong to G. aequa as examination of his specimens (B.M.N.H.,
P.41766) has revealed.

Subbotina (1947, 1953) described as G. crassata (Cushman) forms which are
actually G. aequa Cushman & Renz.

Sjutskaya (1956) described as Globorotalia praenartanensis sp. nov., a form which
appears to be identical with G. aegua and is thus considered to be a junior synonym.

Said & Kenawy (1956) described as Tvuncorotalia crassata aequa, forms which are
not related to this species, but which probably belong to G. avagonensis Nuttall as can
be seen from their figures.

Loeblich & Tappan (1957a) described as G. aequa, forms with a marginal keel,
although G. aequa has no keel. These forms most probably belong to G. quetra
Bolli, G. loeblicht sp. nov. and to other undescribed forms.

The form described by Olsson (1960) as G. aeqgua is apparently G. angulata angulata
(White) and that described by Kitipper (1961) as G. (Tvuncorotalia) aequa, may be
transitional to G. angulata angulata (White).

Hillebrandt (1962) considered G. aequa as a group of three distinct subspecies,
namely :

Globorotalia (ITvuncorotalia) aequa aequa Cushman & Renz.

Globorotalia (Truncorotalia) aequa simulatilis (Schwager).

Globorotalia (Truncorotalia) aequa marginodentata (Subbotina).
He also considered both G. vex Martin and G. kolchidica Morozova to be junior
synonyms of G. simulatilis (Shwager), and G. formosa gracilis Bolli to be a junior
synonym of G. marginodentata Subbotina, and then regarded both G. simulatilis and
G. marginodentata to be two distinct subspecies of his Globorotalia (Truncorotalia)
aequa group. However, Berggren (1960a : 58) stated that “‘ G. subbotinae Morozova,
may be the correct name for G. marginodentata Subbotina if the two species should
prove to be synonymous. Illustrations and descriptions in several Russian papers
appear to indicate their identity, although a resemblance of G. subbotinae to G.
wilcoxensis is also noted in some cases. A study of type material has shown Globo-
votalia marginodentata Subbotina to be a synonym of G. vex Martin.”’ In other words,
it is understood from Berggren’s statement that both G. marginodentata Subbotina
and G. vex Martin are possibly junior synonyms of G. subbotinae Morozova, but the
brief description of the latter species does not allow any decision. Until this con-
fusion is cleared up by examination of the holotypes of Globorotalia simulatilis
(Schwager), G. subbotinae Morozova, G. vex Martin, G. marginodentata Subbotina,
G. formosa gracilis Bolli and G. kolchidica Morozova, it is best to keep Globorotalia
aequa Cushman & Renz as a separate species.

Globorotalia aequa Cushman & Renz is distinguished by its large, strongly umbilico-
convex test ; its distinctly lobate, serrate periphery ; its small number of chambers
which increase very rapidly in size in the last whorl, and its last chamber which

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 193

usually constitutes about one third of the test ; its curved, depressed, dorsal sutures,
and radial strongly depressed ventral ones ; its large, crescentic aperture ; and its
granular spinose surface.

The species is believed to have evolved from Globorotalia angulata angulata
(White) in Upper Paleocene time by the increase in the surface rugosity, in the size of
test and in the rate of chamber growth. All transitional stages between these two
species were recorded in the lower part of the Upper Paleocene G. velascoensis Zone
of the Esna—Idfu region. On the other hand, G. aequa is believed to have evolved
into G. loeblicht sp. nov. by a reduction in the size of test and in the surface rugosity ;
by the development of a distinct, finely beaded keel, a delicately papillose surface and
a narrower umbilicus.

HypotyPe. P.45502.

HoRIzoN AND LOCALITY. Figured specimen, from Sample No. 55, Gebel Owaina
section.

STRATIGRAPHICAL RANGE. The species was first recorded from the Paleocene
Soldado formation of Trinidad which was described by Cushman & Renz (1942) as
“ Eocene, Midway, Soldado formation.....

Bolli (19570) and Loeblich & Tappan (19572) reported this species from the Upper
Paleocene—Lower Eocene of the Lizard Springs formation of Trinidad, and of the
Gulf and Atlantic Coastal plains of the U.S.A. respectively.

All reliable references show that G. aequa is an excellent index fossil for the Upper
Paleocene in most parts of the world.

In the Esna—Idfu region, Globorotalia aequa floods the upper part of the G. velasco-
ensis Zone, characterizing together with G. esnaensis the G. aequa/G. esnaensis
Subzone, of uppermost Paleocene age. It crosses the Paleocene-Lower Eocene
boundary and occurs as a rare form with a much smaller test and a rougher surface in
the overlying G. wilcoxemiss Zone.

Globorotalia africana sp. nov.
(Pl. 23, figs. 4a-c)
Diacnosis. A Globorotalia with small, concavo-convex, compressed test ; spinose

surface ; small, globular, raised early chambers and compressed lenticular later ones ;
very large last chamber ; acute axial periphery and partially developed pseudo-keel.

DEscRIPTION. Test small, concavo-convex, compressed and coiled in a low trocho-
spire ; dorsal side gently convex with the early chambers slightly raised above the
circumambient last whorl ; ventral side gently concave although the chambers are
inflated ; equatorial periphery ovoid, elongate, distinctly lobate and spinose ; axial
periphery acute with a partially developed pseudo-keel on the last chamber ; on the
dorsal side the chambers are 16, arranged in 3 dextrally coiled whorls ; the initial
chambers increase slowly in size, are extremely small, globular, inflated, almost
indistinct, and are followed by relatively larger, globular, inflated chambers which
increase moderately in size ; the last whorl is composed of 6 relatively large chambers

194 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

which are globular in the early part, becoming gradually more compressed towards
the last chamber, which is roughly lenticular and constitutes more than one-third of
the test ; the 6 chambers on the ventral side increase moderately in size (except for
the last) and are roughly lenticular, slightly inflated, and compressed ; sutures on
the dorsal side short. very gently curved to almost straight, depressed ; on the
ventral side they are relatively long, straight, radial and strongly incised ; umbilicus
small, shallow and open ; aperture interiomarginal, extraumbilical-umbilical, a low
arch with a small, delicate lip ; wall calcareous, perforate ; surface delicately spinose
especially along the periphery.

DIMENSIONS OF HOLOTYPE.

Maximum diameter =. 0-30,
Minimum diameter = 0:201mm.
Thickness = 0-14 mm. (of last chamber)

REMARKS. Globorotalia africana sp. nov. is distinguished from the closely related
G. sibaiyaensis sp. nov. by its concavo-convex test, numerous chambers, acute axial
periphery, partially developed pseudo-keel, raised, globular early chambers and
compressed lenticular later ones.

The only known Paleocene Globorotalia species with a gently curved plane of
coiling along which the test grows in such a way as to produce a shallow concavo-
convex form, is Globorotalia kilabiyaensis sp. nov. from the underlying Danian rocks.
This species may represent the ancestral stock from which G. africana evolved,
although G. kilabiyaensis was not recorded from rocks younger than Upper Danian,
while G. africana was only recorded from the uppermost Paleocene.

HOLOTYPE. P.45593.
HorRIZON AND LOCALITY. Holotype from sample No. 50, Gebel Owaina section.

STRATIGRAPHICAL RANGE. The species is a rare form in the G. aequa-—G. esna-
ensis Subzone of uppermost Paleocene age.

Globorotalia angulata abundocamerata Bolli
(Pl. 22, figs. 2a—c)

~

1947 Globorotalia conicotruncata Subbotina (pars) : 115, pl. 4, figs. 11-13 ; pl. 9, figs. 9-11.

1949 Globorotalia (Tvuncorotalia) velascoensis (Cushman) ; Cushman & Bermudez: 41,
pl. 8, figs. 4-6

1951a Globorotalia velascoensis (Cushman) ; Nakkady : 54, pl. 1, fig. 6.

1953 Acarinina conicotruncata (Subbotina) Subbotina (pars) : 220-222, pl. 20, figs. 5a—g¢,
non figs. 10a—I2¢c.

1956 Globorotalia angulata White var. Kubanensis Sjutskaya : 93-94, pl. 3, figs. 4a—c.

1957@ Globorotalia trichotrocha Loeblich & Tappan : 195, pl. 50, figs. 5a—c ; pl. 57, figs. 1a—2c.

19574 Globorotalia apanthesma Loeblich & Tappan (pars) : 187-188, pl. 55, figs. 1a—c only.
Non pl. 48, figs. ta—c ; pl. 58, figs. 4a-c ; pl. 59, figs. 1a—c.

19576 Globorotalia angulata abundocamerata Bolli: 74, pl. 17, figs. 4-6.

1959 Globorotalia velascoensis (Cushman) ; Nakkady : 462, pl. 4, figs. 4a—c.

1960b Globovotalia angulata abundocamerata Bolli ; Bolli & Cita : 19-20, pl. 33, figs. 6a—c.

~u

~

weu

~~

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 195

? 1961 Globorotalia convexa Subbotina ; Said & Kerdany : 329, pl. 1, figs. 7a-c.
1962 Globorotalia (Truncorotalia) angulata (White) ; Hillebrandt : 131-132, pl. 13, figs.
I4a-15¢c.

DEscrRIPTION. Test large, planoconvex, umbilico-convex, coiled in a very low
trochospire ; dorsal side almost flat and very slightly imbricate ; ventral side distinctly
convex and strongly protruding ; equatorial periphery circular, slightly lobate ;
axial periphery subacute, with a faint, delicately beaded keel in the early part which
fades out gradually towards the last chamber ; the 17 chambers on the dorsal side
increase slowly in size and are arranged in 2% sinistrally coiled whorls ; the initial
chambers are small, very slightly inflated, globigerine, and are followed by closely
coiled crescentic chambers ; the last whorl is composed of 7 chambers which enlarge
so slowly that they appear to be roughly equal in size ; the 7 chambers on the ventral
side are relatively large, strongly inflated, roughly conical, distinctly angular and
strongly truncate laterally ; sutures on the dorsal side curved, slightly depressed, on
the ventral side radial, strongly depressed ; umbilicus relatively narrow, deep and
open ; aperture a narrow slit, interiomarginal, extraumbilical-umbilical ; wall
calcareous perforate ; surface finely pitted, with the ridges between the pits simulating
stout spine-like projections covering the surface, especially on the ventral side, and
thus the test appears as if it is granular or subspinose.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter = /0"41 mm.
Minimum diameter == @-97 mam.
Thickness = 0°25 mim.

MAIN VARIATION.

I. Chambers 14-18, arranged in 2-34 whorls, generally sinistrally coiled, but
dextral forms also occur (of 40 specimens chosen at random, 26 coiled
sinistrally).

2. Chambers in the last whorl 6-7.

REMARKS. Globorotalia angulata abundocamerata was first described by Bolli
(19570) as a new subspecies to distinguish the multi-chambered forms of Globoro-
talia angulata from the form with few chambers originally described by White (1928).

Subbotina (1947, 1953) described as Globorotalia conicotruncata and Acarinina
conicotruncata respectively, forms which most probably belong to both G. angulata
abundocamerata and G. angulata angulata. However, examination of the holotype of
G. conicotruncata Subbotina is needed before using her name for the present sub-
species.

Sjutskaya (1956) described as Globorotalia angulata (White) var. kubanensis a form
which probably belongs to the present subspecies. However, as her description
was very brief, Bolli’s name is used here. If Sjutskaya’s varietal name is later
proved to be a senior synonym it should be raised to subspecific rank as warranted by
its morphological features and stratigraphical range. Again, comparison with the
holotype of G. contcotruncata Subbotina may prove both Sjutkaya’s variety and the
present subspecies to be junior synonyms of G. conicotruncata. In its turn the latter

196 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

species should be considered as a subspecies of G. angulata (White) and therefore
its name should be G. angulata conicotruncata Subbotina.

Said & Kerdnay (1961, pl. 7, figs. 13a-c) described as G. angulata abundocamerata
Bolli, a form which is completely different from Bolli’s original description and
figures. On the other hand, these authors described as Globorotalia convexa Subbo-
tina, forms which most probably belong to G. angulata abundocamerata.

The form, described as G. conicotruncata Subbotina by Said (1960) from the
Lower Eocene Thebes limestone formation of Luxor, Egypt, is neither related to the
form described by Subbotina nor to the present subspecies.

Globorotalia angulata abundocamerata is distinguished by its large, circular
umbilico-convex test ; its 6~7 chambers in the last whorl, which increase very slowly
in size ; its curved, depressed dorsal sutures, and radial, strongly incised ventral ones ;
its small, deep umbilicus ; and partially developed keel. Some of the 6-chambered
forms described as G. angulata (White) by various authors, probably belong to this
subspecies.

Globorotalia angulata abundocamerata is believed to have evolved from G. angulata
angulata (White), and into G. velascoensis velascoensis (Cushman) as suggested by their
morphological features and stratigraphical ranges. However, it is not excluded that
G. angulata abundocamerata also evolved into G. apanthesma Loeblich & Tappan by
the development of the highly rugose surface.

HyYpotyPeE. P.45594.

HoRIZON AND LOCALITY. Figured specimen, from sample No. 39, Gebel Owaina
section.

STRATIGRAPHICAL RANGE. G. angulata abundocamerata was first described from
the Paleocene lower Lizard Springs formation of Trinidad (Bolli 19570). It was also
recorded from the Paleocene of northern Italy (Bolli & Cita 1960a, b) where its range
was wrongly considered as Danian—Lower Montian, although the rest of the planktonic
Foraminifera indicated a Middle—basal Upper Paleocene age. Subbotina (1953)
recorded her Acarinina comicotruncata which is partly synonymous with this sub-
species, from the zone of the Danian Foraminifera which Berggren (1960d), quite
justifiably, regards as belonging somewhere between the Middle and the top of the
Paleocene.

Sjutskaya (1956) considered G. angulata and its two varieties—praepentacamerata
and kubanensis as the index forms of the Paleocene in the Sub-Caucasus.

G. angulata abundocamerata was also described as G. velascoensis from the so-
called Danian of the Kharga Oasis, Egypt, which is actually Middle Paleocene
(Nakkady 1959), and as G. convexa from the so-called Landenian of the Farafra Oasis,
Egypt (Said & Kerdany 1961).

Most of the G. angulata (White) records probably included in part the present
subspecies.

In the Esna—Idfu region, G. angulata abundocamerata appears as a common to a
flood form slightly higher in the section than the first appearance of G. angulata
angulata and then decreases gradually, dying out in the basal part of the G. velasco-

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 197

ensis Zone. Although one specimen, probably referable to this subspecies, was
found in the uppermost part of the G. velascoensis Zone, this subspecies is still
considered to be mainly restricted to the upper part of the Middle Paleocene.

Globorotalia angulata angulata (White)
(Pl. 22, figs. 1a—c)

1928a Globigerina angulata White : 191-192, pl. 27, figs. 13a-c.

1937) Globorotalia angulata (White) Glaessner (pars) : 383, pl. 4, figs. 35, 37, non fig. 36.

1947 Globorotalia conicotruncata Subbotina (pars) : 115, pl. 4, figs. 11-13 ; pl. 9, figs. 9-11.

1953 Acarinina conicotruncata (Subbotina) Subbotina (pars) : 220-222, pl. 20, figs. 1oa—c,
I2a—c, ? Ita—c, non figs. 5a—gc.

1955 Tvuncorotalia angulata (White) ; Dalbiez & Glintzboeckel (in Cuvillier ef al., 1955) :
533, 534, pl. 1, figs. 5a—c.

1956 Globorotalia angulata (White) ; Sjutskaya : 92-93, pl. 3, figs. 2a—-c.

1956 Globorotalia angulata (White) var. praepentacamerata Sjutskaya ; 94-95, pl. 3, figs. 3a—c.

19570 Globorotalia angulata (White) ; Bolli: 74, pl. 17, figs. 7-9.

19574 Globorotalia angulata (White), Loeblich & Tappan (pars) : 187, pl. 48, figs. 2a-c ;
pl. 55, figs. 2a—c, 6a—c, 7a-c ; pl. 58, figs. 2a-c ; pl. 54, figs. 5a-c ; non pl. 45, figs. 7a-+,
and pl. 50, figs. 4a—c.

?1957a Globorotalia apanthesma Loeblich & Tappan : 187, pl. 48, figs. Ia—c.
21959 Globorotalia quadvata Nakkady & Talaat ; in Nakkady : 462, pl. 7, figs. 3a—c.

1960 Globorotalia angulata (White) ; Olsson : 44, pl. 8, figs. 14-16.

1960b Globorotalia angulata (White) ; Bolli & Cita : 18-19, pl. 33, figs. 8a—c.

1962 Globorotalia angulata (White) ; Gartner & Hay : 559-560, pl. 1, figs. 6a—c.

DESCRIPTION. Test medium sized, planoconvex, umbilico-convex, coiled in a
very low trochospire ; dorsal side almost flat or very slightly inflated, with an imbri-
cate appearance ; ventral side distinctly convex and strongly protruding ; equatorial
periphery roughly quadrangular and distinctly lobate ; axial periphery subacute
with a few stout, spine-like projections but without keel ; chambers on the dorsal
side 15, arranged in 3, dextrally coiled whorls ; the initial chambers are small,
slightly inflated, roughly globigerine, and increase slowly and regularly in size till the
beginning of the second whorl where they start to enlarge rapidly and become
roughly crescentic ; the last whorl is composed of 43, large, slightly inflated chambers,
the last of which is smaller than the penultimate ; on the ventral side the chambers
are 44, large, strongly inflated, distinctly angular and strongly truncate laterally ;
sutures on the dorsal side strongly curved, depressed ; on the ventral side, they are
straight, radial, strongly incised ; umbilicus roughly rectangular in outline, exceed-
ingly small, deep and open ; aperture a long, narrow slit, interiomarginal, extra-
umbilical-umbilical with a delicate, narrow lip ; wall calcareous, finely perforate,
surface granular or rather pitted.

DIMENSIONS OF DESCRIBED SPECIMEN.
Maximum diameter =— 0-390 mi.
Minimum diameter ==) 40200 anm:
Thickness =" 0-250 mim:

198 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

MAIN VARIATION.

1. Chambers 12-15, arranged in 24-3 whorls generally sinistrally coiled (of 510
specimens studied, 80 coiled dextrally).

2. Chambers in the last whorl 4-5 ; 44 is most common, but specimens with 5-6
chambers also occur and are considered transitional to G. angulata abundo-
camerata. The last chamber is in most cases smaller than the penultimate.

3. The surface may be moderately or strongly roughened, especially on the
ventral side and along the periphery.

REMARKS. The present subspecies was first described by White (1928) as Globi-
gerina angulata. Glaessner (1937b) removed it from Globigerina to Globorotalia
because of the truncata, angular shape of its chambers. Dalbiez & Glintzboeckel
(in Cuvillier et al. 1955) and Hillebrandt (1962) considered this species to belong to
Truncorotalia, while Bermudez (1961) considered it to belong to Pseudogloborotalia.
Bolli (19570), Loeblich & Tappan (1957a), Olsson (1960) and Bolli & Cita (1960d),
considered the species to belong to the genus Globorotalia.

Loeblich & Tappan (1957a) apparently confused G. angulata White with forms
which probably belong to Globorotalia occlusa Loeblich & Tappan (see synonymy).

Nakkady (1959) described as G. angulata (White) a form which is completely
different from White’s original description and figures. However, Nakkady &
Talaat (tn Nakkady 1959) described as Globorotalia quadrata n.sp., a form which is
probably G. angulata angulata (White).

Grimsdale (1951) stated that G. angulata (White) is probably a junior synonym of
G. simulatilis (Schwager) 1883, but the two forms appear to be distinct, although very
little is known about the holotype of Schwager.

Globorotalia angulata (White) is distinguished by its very low, trochospirally
coiled, umbilico-convex test ; its flat to slightly inflated, imbricate dorsal side, and
strongly protruding ventral one ; its angular, truncate, conical chambers, its acute
to subacute periphery which has no marginal keel but is covered, in well preserved
specimens, with few, stout, spine-like projections which may simulate a keel ; its
4-5 chambers in the last whorl which increase rapidly in size ; its curved, depressed,
dorsal sutures and radial, strongly incised, ventral ones ; its granular or rather pitted
surface ; its very small, deep, open umbilicus, and its long slit-like aperture which
extends to the periphery and is covered by a delicate lip in well preserved specimens.

As mentioned by Bolli (19570) G. angulata angulata (White) probably evolved from
G. uncinata uncinata Bolli in early Middle Paleocene time, although its evolution
from the more closely related G. quadrata (White) is not excluded. On the other hand
it is believed to have evolved in two directions, one leading to G. angulata abundo-
camerata Bolli and the other to G. aequa Cushman & Renz.

HyYpotyPE. P.45595.

HoRIZON AND LocALITy. Figured specimen, from sample No. 35, Gebel Owaina
section.

STRATIGRAPHICAL RANGE. Globorotalia angulata was first described by White
(1928) from the Velasco formation of Mexico, where he recorded it as “‘ a rare form

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 199

in all horizons from the base of the Velasco up into the lower part of the middle
portion of the formation’’. Apparently, he had confused this species with its
ancestor G. uncinata uncinata Bolli or with similar forms in the Lower Velasco and
thus misinterpreted its range. Contrary to White’s observation, Hay (1960)
recorded this species throughout the upper part of the Velasco formation with only
a rare occurrence in the uppermost part of the Lower Velasco, (from the top of the
G. uncinata Subzone to the top of the Globorotalia velascoensis Zone).

In the Esna—Idfu region, G. angulata angulata (White) appears at the basal part of
the Middle Paleocene. It is taken as a stratigraphical marker for the Lower—Middle
Paleocene boundary (i.e. it separates the Danian from the overlying Middle Paleo-
cene) as it has not been found in the type Danian or in the Danian (of reliable
references) elsewhere. Moreover, the first appearance of G. angulata angulata
coincides with the disappearance of the index species of the Danian rocks below, and
with the first appearance of the “‘ Globigerina/truncated Globorotalia assemblage ”’
which is clearly distinguished from the underlying “‘ Globigerina/rounded Globorotalia
assemblage ”’, characteristic of the Danian in its type section and elsewhere.

The subspecies ranges throughout the Middle and Upper Paleocene of the sections
studied. It floods the Middle Paleocene, constituting the main element in plank-
tonic foraminiferal fauna, and characterizes the Globorotalia angulata Zone. It
continues as an abundant to rare form in the overlying G. velascoensis Zone, at the
top of which it dies out completely.

All reliable references show clearly that G. angulata angulata occurs neither in the
Danian nor in the Lower Eocene.

Globorotalia apanthesma Loeblich & Tappan
(Pl. 21, figs. 1a—c)
1957a Globorotalia apanthesma Loeblich & Tappan : 187-188, pl. 59, figs. 1a—c only ; non
pl. 48, figs. ra—c ; pl. 55, figs. 1a—c ; pl. 58, figs. 4a—c.

? 1960 Globorotalia apanthesma Loeblich & Tappan, Olsson : 45, pl. 8, figs. 17-19.

DEscripTION. Test large, planoconvex, umbilico-convex, coiled in a very low
trochospire ; dorsal side almost flat, slightly imbricate ; ventral side strongly
protruding ; equatorial periphery subcircular, moderately lobate ; axial periphery
subacute with the thick, stout, spine-like projections simulating a marginal keel ;
chambers on the dorsal side about 16 in number, increasing gradually in size and
arranged in 3 dextrally coiled whorls ; the initial chambers are small, indistinct and
almost masked by the surface rugosity ; they are followed by relatively large crescen-
tic chambers ; the last whorl is composed of 6 large, almost flat, slightly imbricate
chambers (one of which is broken) ; these are roughly crescentic in the early part,
quadrangular to hemispherical later ; on the ventral side the chambers are 6 (5 + I
broken), large, inflated, angular conical and strongly protruding ; sutures on the
dorsal side curved, depressed ; on the ventral side they are radial, strongly incised ;
umbilicus very wide, deep and open ; aperture interiomarginal, extraumbilical-
umbilical, a broad, arched opening with a narrow delicate lip (only seen in well-
preserved specimens) ; wall calcareous, perforate ; surface rough, distinctly nodose,

200 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

with the nodes tapering out in the form of stout, spine-like projections, especially
along the periphery and on the ventral side, and thus simulate a partially-developed
pseudo-keel on the periphery of the early chambers.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter == "0-43 Ini:
Minimum diameter = 0-38 mm.
Thickness = “O25 tim.

REMARKS. Globorotalia apanthesma was first described by Loeblich & Tappan
(19574) who stated that it differs from both G. acuta Toulmin and G. angulata (White).
However, one paratype (pl. 48, figs. 1a—c) is most probably G. angulata angulata
(White), a second (pl. 55, figs. Ia—c) is possibly G. angulata abundocamerata Bolli,
while a third (pl. 58, figs. 4a—c) shows a clearly developed marginal keel, contrary to
the authors’ original description and remarks. Similarly, the form described by
Olsson (1960) as G. asbanthesma appears to be more related to G. angulata angulata
(White).

Globorotalia apanthesma probably evolved directly from G. angulata angulata
(White) or indirectly through G. angulata abundocamerata Bolli by the development
of the heavily spinose surface and wide umbilicus. The morphological features and
stratigraphical ranges of the two species substantiate this proposition. On the
other hand, G. apanthesma is believed to have evolved into G. Mispidicidaris Loeblich
& Tappan, which is morphologically very closely related, and is only found with the
latest stages of development of G. apanthesma.

HypotyPe. P.45596.

HORIZON AND LOCALITY. Figured specimen, from sample No. 40, Gebel Owaina
section.

STRATIGRAPHICAL RANGE. Loeblich & Tappan (1957a) recorded G. apanthesma
from the Aquia formation of Maryland and Virginia, the Vincentown formation of
New Jersey and the Salt Mountain limestone of Alabama, which they considered to
be Upper Landenian (Sparnacian) in age.

It was also recorded by Olsson (1960) from the Hornerstown formation of New
Jersey, which he considered as Thanetian—basal Sparnacian.

In the Esna—Idfu region G. apanthesma ranges throughout the G. velascoensis
Zone (Upper Paleocene), being rare to common at its base increasing gradually in
number towards its upper part (the G. aequa/G. esnaensis Subzone), and dying out
completely at its top.

Globorotalia berggreni sp. nov.
(Pl. 23, figs. 7a-c)
Diacnosis. A Globorotalia with roughly triglobular, compressed, umbilico-

convex test ; extremely reduced umbilicus ; long, slit-like arched aperture and heavily
spinose surface.

DESCRIPTION. Test medium sized, compressed and coiled in a low trochospire ;
dorsal side almost flat, but weakly inflated with the chambers slightly compressed

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 201

towards the periphery ; ventral side strongly inflated ; equatorial periphery roughly
triglobular, distinctly lobate and sharply serrate, without a marginal keel ; axial
periphery subrounded or rather bluntly angular due to the slight compression of the
chambers towards the periphery ; chambers on the dorsal side are not all clear, but
appear to be 11 in number, arranged in 2 dextrally coiled whorls ; the initial chambers
are small, indistinct, and almost masked by the surface rugosity ; the last whorl is
composed of 34 large subglobular, compressed chambers which increase slowly in size
except for the last one which is slightly smaller than the penultimate ; on the ventral
side the chambers are 33, subglobular and strongly inflated ; sutures on the dorsal
side short, curved and strongly depressed ; on the ventral side the sutures are radial
and strongly incised ; umbilicus reduced to an extremely narrow central pit from
which the apertrure starts and the ventral sutures radiate ; aperture interiomarginal
extraumbilical-umbilical, a large, crescentic arch extending almost to the periphery ;
wall calcareous, perforate ; surface rough, heavily nodose, with the nodes tapering
out in the form of stout spine-like projections, especially along the periphery.

DIMENSIONS OF HOLOTYPE.

Maximum diameter ==) 030) iam.
Minimum diameter = - 0:34 mm.
Thickness == -©-26 mim:

REMARKS. Globorotalia berggrent sp. nov. differs from G. esnaensis (Le Roy) in
its compressed test, smaller size, fewer chambers in the last whorl, subrounded to
subacute axial periphery, much narrower umbilicus and peculiar aperture. The
form described by Berggren (19604, pl. 5, figs. 3a-c) as G. esnaensis (Le Roy) is
different from Le Roy’s original description and figures, but may probably belong to
the present species, although it has more chambers, a more rounded axial periphery
and a more umbilical aperture.

Globorotalia berggreni sp. nov. probably evolved from G. irvorata Loeblich &
Tappan by the development of a more tightly coiled, compressed test, a more spinose
surface, a much narrower umbilicus and a long slit-like aperture. On the other hand,
it might possibly have evolved from G. esnaensis (Le Roy) by the reduction in size of
test, its slight compression, and by the development of the very narrow umbilicus and
the long, slit-like aperture.

This species is named after Dr. W. A. Berggren of the Geological Institute, Univer-
sity of Stockholm, Sweden.

HoLotyPe. P.45597.
PARATYPE. P.45598.

HORIZON AND Locality. Holo- and paratype from sample No. 51, Gebel Owaina
section.

STRATIGRAPHICAL RANGE. The species is a rare form in the upper part of the
G. velascoensis Zone, the G. aequa-G. esnaensis Subzone, of uppermost Paleocene
age.

202 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

Globorotalia bollii sp. nov.
(Pl. 22, figs. 5a—d, 6a—d)
1957) Globorotalia vex Martin ; Bolli: 75, pl. 18, figs. to-12.

Diacnosis. <A Globorotalia with medium-sized test ; perfectly flat dorsal side and
protruding ventral one ; distinctly well-developed, very broad, heavily beaded keel ;
narrow umbilicus and thick, curved, raised, heavily beaded dorsal sutures.

DescrieTION. (Holotype, Pl. 22, figs. 5a-d). Test medium sized, plano-convex,
umbilico-convex, coiled in a very low trochospire ; dorsal side flat ; ventral side
strongly protruding ; equatorial periphery roughly quadrate, distinctly lobate with a
well-developed, broad, heavily beaded marginal keel ; axial periphery acute ;
chambers on the dorsal side about 10, arranged in 2 dextrally coiled whorls ; the
initial chambers are small, globular, compressed, almost masked by the surface
rugosity, and are followed by typically crescentic chambers which increase gradually
in size ; the last whorl is composed of 44, large, crescentic chambers which increase
rapidly in size ; on the ventral side the chambers are 44, large, angular conical
and strongly protruding, with their distal ends meeting closely around the small
umbilicus ; sutures on the dorsal side are thickened, raised, curved and heavily
beaded ; on the ventral side the sutures are radial and strongly depressed ; umbilicus
small, deep and open ; aperture interiomarginal, extraumbilical-umbilical ; wall
calcareous, perforate ; surface delicately papillose on the dorsal side, more heavily
so on the ventral.

DIMENSIONS OF HOLOTYPE.

Maximum diameter = 0:46 mm:
Minimum diameter ==) 0*35 Imm.
Thickness ==) sOr2nmM:

REMARKS. Bolli (1957) described as Globorotalia rex Martin from the upper
Lizard Springs formation of Trinidad, a form which differs from the holotype of
Martin in its perfectly flat dorsal side ; extremely well-developed, much wider,
heavily beaded marginal keel ; thick, raised, beaded dorsal sutures and more tightly
coiled chambers. Bolli stated that this form characterizes the G. vex Zone at the base
of the Eocene.

Globorotalia vex Martin is closely related to G. aequa Cushman & Renz, and may
be a junior synonym of G. stmulatilis (Schwager) although very little is known about
Schwager’s species. On the other hand, the form figured by Bolli (1957b) appears to
be more closely related to the G. velascoensis group, especially to G. velascoensis parva
Rey. It differs from the latter, only in being smaller, having a rougher surface, a
much smaller umbilicus, a less protruding ventral side and a weaker, less ornamented
umbilical shoulder.

Careful examination of G. vex as described and figured by Martin (1943) from the
Lodo formation of California, and by Mallory (1959) from the same formation,
showed that the form described by Bolli (1957b) as G. vex Martin is different and
should be considered separately. It is here named G. bollii n.sp. after Dr. Hans M.
Bolli.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 203

A form with a much rougher surface than the holotype, sub-circular test, and more
chambers in the last whorl (Pl. 22, figs. 6a-d), may well be a transitional stage
between G. velascoensis velascoensis and the present species. This substantiates the
hypothesis that G. bollii evolved from G. velascoensis velascoensis in late Paleocene or
early Eocene time, as suggested by their morphological features and stratigraphical
ranges.

Subbotina (1953, pl. 18, figs. 1a—c) figured as G. marginodentata Subbotina, a form
with a flat dorsal side, which may belong to G. bollit.

Loeblich & Tappan (1957a) described as G. vex Martin a form which appears to
be different from the holotype of Martin (1943), the hypotype of Mallory (1959), and
the present form.

HoLotyPe. P.45599.
PARATYPE. P.45600.

HORIZON AND LOCALITY. Holo- and paratype, from sample No. 68, Gebel Owaina
section.

STRATIGRAPHICAL RANGE. The species is common to rare in the G. wilcoxensis
Zone, which is here considered to represent the basal Eocene ; Bolli’s form was also
recorded from the Lower Eocene of Trinidad.

Globorotalia compressa (Plummer)
(Pl. 17, figs. 1a—3c)

1926 Globigerina compressa Plummer : 135-136, pl. 8, figs. 11a-—c.

19376 Globigerina compressa Plummer ; Glaessner : 382, pl. 4, figs. 32a—-c.

1953 Globigerina compressa Plummer var. compressa Plummer ; Subbotina (pars): 55,
pl. 2, figs. 2a—c ; non figs. 3a—14¢.

1953 Globorotalia membranacea (Ehrenberg) ; Subbotina (pars): 205, pl. 16, figs. 7a-c,
toa—c ; non figs. 8a—9gc, 11a—13¢.

1955 Globorotalia compressa (Plummer) Dalbiez & Glintzboeckel (in Cuvillier et al., 1955) :
533, pl. 1, figs. 3a-c.

1957 Globigerina compressa Plummer ; Troelsen: 129, pl. 30, figs. 5a—c.

19574 Globorotaha compressa (Plummer) ; Loeblich & Tappan : 188, pl. 40, figs. 5a—c ; pl. 41,
figs. 5a—c ; pl. 42, figs. 5a—c ; pl. 44, figs. ga—10c.

1960g Globigerina compressa Plummer ; Hofker : 78-79, text-figs. 35a—c.

1960b Globorotalia compressa (Plummer) ; Bolli & Cita : 20-21, pl. 32, figs. 3a—c.

1962 Globorotalia (Turborotalia) compressa (Plummer) ; Berggren: 94-96, pl. 14, figs. 5a-—c,
text-figs. 13 (1-6).

DESCRIPTION. (Specimen, Pl. 17, figs. 2a—-c). Test small, roughly lenticular,
slightly elongate, compressed, coiled in a very low trochospire, nearly equally bi-
convex, or slightly more convex on the ventral side ; equatorial periphery roughly
ovoid and distinctly lobate ; axial periphery bluntly acute ; 13 chambers on the
dorsal side arranged in 24 dextrally coiled whorls ; the initial chambers are extremely
small, very weakly inflated, globigerine and increase gradually in size ; the last whorl
is composed of 5, relatively large, roughly crescentic chambers which are compressed
and increase more rapidly in size ; the 5 chambers on the ventral side are roughly

204 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

lenticular and increase rapidly in size ; sutures on the dorsal side curved, depressed ;
on the ventral side they are very slightly curved to nearly straight, radial, depressed ;
umbilicus irregular in outline, narrow, shallow and open ; aperture interiomarginal,
extraumbilical-umbilical, a narrow, distinct arch with a delicate, flaring lip on top ;
wall calcareous, finely perforate ; surface smooth.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter = 0°25 mm.
Minimum diameter = o'16 mm.
Thickness = oO:10 mm.

MAIN VARIATION.

1. Chambers 12-15, arranged in 23-3 whorls.

2. Chambers in the last whorl 4-5, rarely 6.

3. Coiling is random with more tendency to dextral coiling (of 95 specimens
chosen at random, 28 coiled sinistrally).

REMARKS. Cushman & Todd (1942), Cushman & Bermudez (1949) and Brénni-
mann (1952) considered this species to belong to Globorotalia although their figured
forms are not true G. compressa (Plummer)

Troelsen (1957), following Brotzen (1948), considerd this species to belong to the
genus Globigerina. Dalbiez & Glintzboeckel (1955), Bolli (1957), Loeblich &
Tappan (19574, b), Olsson (1960), Bolli & Cita (19604, b), Bermudez (1961), Berggren
(1962), and Hillebrandt (1962) removed this species to the genus Globorotala.
Berggren (1962), following Banner & Blow’s Classification (1959), considered G.
compressa to belong to the subgenus Turborotalia, while Hillebrandt (1962), following
Cushman & Bermudez (1949), considered it to belong to the subgenus Globorotalia,
although the latter’s form is not G. compressa (Plummer).

Hofker (1960 g : 78-79), neglecting Cushman & Bermudez (1949), Bolli, Loeblich
& Tappan (1957), and Banner & Blow (1959), considerd this species to belong to the
genus Globigerina stating that “‘ Fine pores also are found at the somewhat compres-
sed periphery so that there can be no reason to call this species a Globorotalia, since
the type of that genus has a distinctly poreless and sharp periphery.” However,
because of the extraumbilical-umbilical position of the aperture, this species is here
considered to belong to the genus Globorotalia.

Globorotalia compressa (Plummer) is distinguished by its small, compressed,
biconvex test ; its strongly curved, depressed sutures on the dorsal side ; its radial,
depressed ventral sutures ; and its very smooth surface.

The species is believed to have evolved from G. pseudobulloides (Plummer) during
the uppermost part of the Middle Danian time. On the other hand, it is believed
to have evolved in two directions : one leading to Globorotalia emulei sp. nov. and the
other to Globorotalia ehrenbergi Bolli. Globorotalia ehrenbergi is believed to be a
transitional stage between G. compressa (Plummer) and G. pseudomenardu Bolli,
although Loeblich & Tappan (1957a: 188) considered it synonymous with G.
compressa (Plummer). Berggren (1962 : 96), stated that “ the writer has compared
the holotype of G. ehrenbergi (U.S.N.M.P. 5060), metatypes and topotypes of G.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 205

compressa and labelled specimens of G. membranacea from the Lower Foraminiferal
beds of the northern Caucasus and has concluded that G. ehrenbergi and G. compressa
are distinct species.”’

Jennings (1936), Toulmin (1941), Cushman & Todd (1942), Shifflett (1948),
Brénnimann (19520), Hamilton (1953) and Reyment (1960) described as G. compressa,
forms which probably belong to Globorotalia emilet sp.nov. Cushman & Bermudez
(1949), Subbotina (1953, pars), Olsson (1960), and Hillebrandt (1962) described as
G. compressa, forms which are probably Globorotalia pseudobulloides (Plummer).

Subbotina (1953) had confused G. compressa (Plummer) with both G. pseudo-
bulloides (Plummer) and G. ehrenbergi Bolli, while Hofker (1956c, 1958a) described as
Globigerina compressa Plummer, forms which are completely different from Plum-
mer’s original description and figures (see synonymy).

HypotypPes. P.45601-03.

HORIZON AND LOCALITY. Figured specimens, pl. 17, figs. 1a—c, from sample
No. 31, Gebel Owaina section ; figs. 2a—c, from sample No. 30, Gebel Owaina section ;
figs. 3a—c, from sample No. 7, Gebel El-Kilabiya section.

STRATIGRAPHICAL RANGE. Globorotalia compressa (Plummer) was first described
from the upper Midway group of Texas (the Wills Point Formation), which, according
to Loeblich & Tappan (19574, b) is of Upper Danian age.

It was also recorded from the Upper Danian at its type locality in Denmark, and
in southern Sweden (Bronnimann 1953 ; Reichel 1953 ; Troelsen 1957 ; Loeblich &
Tappan 19574, b ; Hofker 1960g ; and Berggren 1960), 1962).

All reliable records show that G. compressa (Plummer) is a very short ranging
species, restricted to the Upper Danian. All records of G. compressa from the Mae-
strichtian (e.g. Meyer 1959 and Hofker 1958a, etc.), from the Middle or Upper
Paleocene, or from the Lower Eocene (e.g. Jennings 1936 ; Toulmin 1941 ; Cushman
& Todd 1942 ; Shifflett 1948 ; Bronnimann 1952) ; Hamilton 1953 ; Bolli 19570, and
Reyment 1960) are found to be erroneous. Again, the extension of the range of the
present species throughout the Danian (e.g. Hay 1960) or throughout the Danian
and the Lower Montian (e.g. Bolli & Cita 19604, b) is incorrect.

In the Esna—Idfu region, G. compressa (Plummer) occurs as a common to abundant
form in the Upper Danian and dies out completely before the first appearance of
G. angulata angulata (White) which marks the Danian—Middle Paleocene boundary.

Globorotalia cf. convexa Subbotina
(Pl. 22, figs. 3a—c)

? 1953 Globorvotalia convexa Subbotina : 209, pl. 17, figs. 2a—3c.

? 1957a Globorotalia convexa Subbotina ; Loeblich & Tappan : 188-189, pl. 48, figs. 4a-—c ;
pl. 50, figs. 7a-c ; pl. 53, figs. 6a—8c ; pl. 57, figs. 5a—6c ; pl. 61, figs. 4a—c ; pl. 63, figs. 4a—c.
DESCRIPTION. Test medium sized, unequally biconvex, coiled in a low trocho-

spire ; dorsal side slightly raised ; ventral side strongly inflated ; equatorial periphery

subcircular, moderately lobate ; axial periphery rounded ; chambers on the dorsal

206 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

side 15, arranged in 2% sinistrally coiled whorls, increasing gradually in size ; the
initial chambers are small, inflated, globigerine and are followed by typically crescen-
tic, overlapping chambers which increase moderately in size ; the last whorl is
composed of 5 relatively large, inflated chambers ; on the ventral side the chambers
are 5, large, roughly triangular and strongly inflated ; sutures on the dorsal side are
strongly curved, depressed in the early part, short, slightly curved and depressed in
the later part ; on the ventral side they are almost straight, radial and depressed ;
umbilicus narrow, shallow and open ; aperture interiomarginal, extraumbilical-
umbilical, a long, narrow arch bordered above by a narrow delicate lip ; wall
calcareous, perforate ; surface rough, nodose.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter = /.5 7 On.
Minimum diameter = (0°20.
Thickness = 0:23 mm. (Of last chamber)

REMARKS. Globorotalia convexa was first described by Subbotina (1953) who
mentioned that it had a wide range of variation and a long stratigraphical range.
The form described here differs from the holotype of G. convexa in being much larger,
in having fewer chambers in the last whorl, a more rounded axial periphery and a
more protruding ventral side. It might possibly have evolved into G. convexa, as
suggested by their stratigraphical distribution.

Globorotalia cf. convexa is believed to have evolved from the morphologically
similar G. favagi sp. nov. by the development of a more tightly coiled test and by an
increase in surface rugosity.

Globorotalia convexa of Olsson (1960) is probably G. nicola Martin, that of Berggren
(19604) is possibly G. favagi sp. nov. and the one of Said & Kerdany (1961) is most
probably G. angulata abundocamerata Bolli. The form figured by Gartner & Hay
(1962) as G. convexa has triangular chambers on the dorsal side instead of chambers
with the alar or semicircular outline described by Subbotina.

HypotyPe. P.45604.

HORIZON AND LOCALITy. Figured specimen, from sample No. 37, Gebel Owaina
section.

STRATIGRAPHICAL RANGE. The species was first described by Subbotina (1953)
from the “ zone of conical Globorotalias’’ of the northern Caucasus, which she
considered as Lower—Middle Eocene, but is regarded by Berggren (1960d) on the
basis of its planktonic Foraminifera, to indicate an Upper Paleocene—Lower Eocene
age.

Subbotina recorded this species to range from the “‘ Danian? ”’ to the Middle
Eocene, occuring in the zones of “‘Rotalia-like Globorotalias ’’, “‘ flattened Globoro-
talias’’, and ‘‘ conical Globorotalias’”’ of the northern Caucasus. It was also
recorded from the Paleocene—? Lower Eocene of the Gulf and Atlantic Coastal
Plains and from the Velasco formation of Mexico (Loeblich & Tappan 1957a ; Hay
1960), and from the Ilerdian ‘‘ marne bleue ”’ of Mont Cayla, France (Gartner & Hay
1962).

”

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 207

In the Esna—Idfu region G. cf. conexa appears in the basal part of the G. velasco-
ensis Zone (Upper Paleocene) : it continues as a rare form throughout this zone, and
dies out completely at its top.

Globorotalia ehrenbergi Boll
(Pl. 17, figs. 5a—c)

1957) Globorotalia ehvenbergi Bolli: 77, pl. 20, figs. 18-20.
1960b Globorotalia ehrenbergi Bolli ; Bolli & Cita : 21-22, pl. 33, figs. 4a—c.

DEscripPTIon. Test small, roughly lenticular, compressed, coiled in a very low
trochospire ; dorsal side very gently convex ; ventral side very slightly inflated ;
equatorial periphery roughly circular, strongly lobate ; axial periphery acute,
with a faintly developed keel on the last chamber (partially damaged on the figured
specimen) ; about 15 chambers on the dorsal side, increasing slowly in size at first but
more rapidly later, arranged in 23-3 whorls ; the initial chambers are exceedingly
small, indistinct, globigerine and slightly inflated ; the chambers of the second whorl
are relatively larger, globular to roughly crescentic, and compressed ; the last whorl
is composed of 5, relatively large, roughly lenticular, compressed chambers, which
increase moderately in size ; the 5 chambers on the ventral side are roughly triangular
and slightly inflated ; sutures on the dorsal side are slightly curved, distinctly
depressed ; on the ventral side they are almost straight, radial and strongly incised ;
umbilicus small, shallow and open ; aperture interiomarginal, extraumbilical-
umbilical, a narrow long arch, covered by a delicate lip ; wall calcareous, perforate ;
surface smooth.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter == "O"25 Hh.
Minimum diameter == (6)-216) inaani
Thickness == (000) sonpane

REMARKS. Globorotalia ehrenbergi is distinguished by its small, lenticular,
compressed, smooth test ; its curved, depressed dorsal sutures, and radial, incised
ventral ones ; its acute axial periphery and weakly developed partial keel ; its small
shallow umbilicus ; and its narrow, long aperture with its delicate apertural lip.

This species was previously included by various authors within Globorotalia
membranacea (Ehrenberg), a recognized nomen nudum, under which several morpho-
logically and stratigraphically distinct forms had been described. In addition to
the known Paleocene species such as G. compressa (Plummer), G. ehrenbergi Bolli,
G. emilei sp. nov., G. pseudomenardi Bolli, various other forms from stratigraphically
distinct horizons were considered as G. membranacea (Ehrenberg). Subbotina (1953),
for example, included under G. membranacea (Ehrenberg), forms which are actually
G. compressa, G. ehrenbergi and G. pseudomenardit.

G. ehrenbergi probably evolved from G. compressa, and is considered as an inter-
mediate stage between it and G. pseudomenardii. This is substantiated by their
morphological characters and stratigraphical ranges, although it is not excluded

208 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

that G. ehrenbergi has possibly evolved from G. imitata Subbotina ; extremely
compressed forms of G. imitata closely resemble G. ehrenbergi and may be transitional
to it.

Again, as previously mentioned above (pp. 204, 205), Loeblich & Tappan (1957a :
188) included G. ehrenbergi in their synonymy of G. compressa, but the stratigraphical
ranges and morphological characterisitcs of the two species substantiate their
separate identity.

HypotyPe. P.45605.

HoRIzZON AND LOCALITy. Figured specimen, from sample No. 37, Gebel Owaina
section.

STRATIGRAPHICAL RANGE. The species was described by Bolli (19570) from the
Paleocene, lower Lizard Springs formation of Trinidad, where it was found to range
throughout the G. pusilla pusilla Zone and the lower part of the G. pseudomenardu
Zone, here considered as upper Middle Paleocene—lower Upper Paleocene respectively.

It was recorded from almost the same horizon in the Paderno d’Adda section of
northern Italy (Bolli & Cita 1960a, b), from the Paleocene Madruga formation of
Cuba (Cushman & Bermudez 1949) as G. membranacea (Ehrenberg), the Paleocene of
the Caucasus region (Subbotina 1953), the Lower Paleocene of Nekhl section,
northern Sinai, Egypt (Said & Kenawy 1956), and from the Danian—Landenian of
Austria (Hillebrandt 1962) : this last author apparently confused G. ehrenbergi with
various other forms as can be seen from his figures.

In the Esna—Idfu region G. ehrenbergi appears in the Upper Danian and continues
as a rare to common form to the basal part of the Upper Paleocene G. pseudomenardu
Subzone.

Globorotalia emilei sp. nov.
(Pl. 17, figs. ga—c)

1936 Globigerina compressa Plummer ; Jennings : 193, pl. 4 (31), fig. 8.

1941 Globigeyina compressa Plummer ; Toulmin : 607, pl. 82, figs. 1, 2.

1942 Globigeyina compressa Plummer ; Cushman & Todd (pars) : 44, pl. 8, fig. 6 ; non fig. 5.

1952b Globigerina compressa Plummer ; Bronnimann : 25, pl. 2 (12), figs. 19-24.

1953 Globorotalia membranacea (Ehrenberg) ; Le Roy : 32, pl. 3, figs. 13-14.

1953 Globigeyina compressa Plummer ; Hamilton : 221, pl. 31, figs. 14, 15.

1957) Globorotalia elongata Glaessner ; Bolli : 77-78, pl. 20, figs. 11-13.

1957a Globorotalia elongata Glaessner ; Loeblich & Tappan (pars) : 189, pl. 45, figs. 5a—c ;
pl. 46, figs. 5a-c ; ? pl. 49, figs. 7a-c ; pl. 54, figs. 1a—4c ; pl. 59, figs. 4a-c ; pl. 60, figs.
ga—c ; non pl. 48, figs. 5a—c ; pl. 54, figs. 5a-c ; pl. 63, figs. 2a—c.

1960 Globovotalia elongata Glaessner ; Olsson : 45-46, pl. 9, figs. 4-6.

Se Ce eS)

Diacnosis. A Globorotalia with elongate, very low trochospiral, slightly com-
pressed test ; subrounded to subacute axial periphery ; crescentic, rapidly enlarging
chambers in last whorl ; curved, depressed, dorsal sutures and nearly radial, incised
ventral ones ; smooth surface and wide, open umbilicus.

DeEscrIPTION. Test medium sized, unequally biconvex, compressed, coiled in a
very low trochospire ; dorsal side almost flat although the chambers, especially the

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 209

last one, are slightly inflated ; ventral side moderately inflated ; equatorial periphery
roughly ovoid, elongate and moderately lobate ; axial periphery bluntly acute, witha
faintly developed pseudo-keel on the last chamber ; chambers on the dorsal side
nearly 13, arranged in two dextrally coiled whorls ; the initial chambers are very
small, indistinct and are followed by crescentic, overlapping chambers ; the last
whorl is composed of 6, large, slightly inflated, compressed chambers which increase so
rapidly in size that the last chamber constitutes about } of the test ; the 6 chambers
on the ventral side increase rapidly in size and are inflated, triangular to sub-globu-
lar ; sutures on the dorsal side curved, strongly depressed ; on the ventral side they
are nearly radial and distinctly depressed ; umbilicus elongate in outline, fairly wide
and open ; aperture a low, narrow arch, interiomarginal, extraumbilical-umbilical ;
wall calcareous, perforate ; surface delicately papillose in the early part, becoming
smoother towards the last chamber.

DIMENSIONS OF HOLOTYPE.

Maximum diameter == 0-34 mm.
Minimum diameter == Owe? iano
Thickness = 6-14 mm.

MAIN VARIATION.

1. Chambers in the last whorl 4-6.

2. Coiling is fairly random but with a tendency to be dextral ; (of 47 specimens
studied, 28 coiled dextrally).

3. The axial periphery is either rounded or pinched out to form a thin pseudo-keel.

REMARKS. Globorotalia emilei sp. nov. is morphologically similar to G. compressa
(Plummer), G. inflata Hussey, G. planoconica Subbotina, G. pseudomenardi Bolli
and G. pseudoscitula var. elongata Glaessner. It is distinguished from G. compressa
by its larger, less compressed test, radially elongate last chamber and partially
developed marginal keel. Globorotalia inflata Hussey which was described from the
Eocene, Claiborne, Cane River formation of Louisiana, is morphologically very
similar, although it was very briefly described. However, apart from the difference
in stratigraphical range it appears to be more planoconvex, strongly umbilico-convex,
with a much deeper umbilicus and a well-developed apertural lip, and to lack the
partially developed marginal keel. Globorotalia planoconica Subbotina is much
smaller, with a planoconvex more tightly coiled test, a much narrower umbilicus, less
radially elongate last chamber, an occasional entire keel and an apertural lip.
G. pseudomenardit Bolli is distinguished by its chambers which increase more rapidly
in size, its well-developed marginal keel and sharply acute axial periphery. G.
pseudoscitula var. elongata Glaessner is much smaller, has a raised dorsal spire with a
much flattened last chamber, more tightly coiled test, less lobate periphery and more
curved ventral sutures. It was described from the so-called Lower Eocene of
northwestern Caucasus, while the present species was only recorded from the Middle
and lower Upper Paleocene. Glaessner’s variety needs more detailed description
and its stratigraphical range needs to be more precisely defined to prove its relation-
ship to the present species, which may represent the ancestral stock from which it has

210 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

directly or indirectly evolved, and with which it has been often confused. Bolli
(19570) raised this variety to specific rank, changing its name to G. elongata Glaessner.
However, the forms figured by him are different from the holotype of Glaessner, but
most probably belong to the present species. He was followed by Loeblich & Tappan
(1957a), Olsson (1960) and Hillebrandt (1962). Loeblich & Tappan included in
G. elongata forms which are identical with the present species, and others which lack
the radially elongated last chamber, characteristic of the species (see synonymy).
These forms, as can be seen from their figures, should be considered separately.
The form figured by Olsson (1960) as G. elongata Glaessner conforms well with the
present species, while that described by Hillebrandt is different from both the holo-
type of Glaessner and the present form.

Globorotalia emilet sp. nov. was confused with G. membranacea (Ehrenberg)
and with G. compressa (Plummer) as seen in synonymy. Globorotalia membranacea,
although much confused, is a Pliocene form, while G. compressa is only known from
the Danian.

Globorotalia enulei sp. nov. is believed to have evolved from G. compressa (Plum-
mer) by the increase in the size of test and the development of the strongly elongated
chambers in the last whorl, and the partially developed keel. On the other hand, it
is believed to have evolved in two directions : one leading to G. pseudomenardi
Bolli, by the development of the marginal keel and the sharply acute axial periphery,
and the other to G. troelseni Loeblich & Tappan, by the development of the tendency
towards a somewhat evolute coiling in the last whorl. The present species is named
after Professor Emile A. Pessagno, Jr., of the University of California, Davis,
California.

HoLotypPe. P.45606.
PARATYPES. P.45668.

HORIZON AND LOCALITY. MHolo- and paratypes, from sample No. 33, Gebel
Owaina section.

STRATIGRAPHICAL RANGE. Globorotaliaemileisp.nov.ranges throughout the Middle
and most of the Upper Paleocene of the Esna—Idfu region. It appears at the base
of the G. angulata Zone, and continues as a common to abundant form to the basal
part of the G. aequa/G. esnaensis Subzone. Bolli (1957) recorded his G. elongata
Glaessner, which most probably belongs to G. emilei, from the Paleocene, lower
Lizard Springs formation of Trinidad, where it was shown to range through the
G. pseudomenardu—G. velascoensis Zones. It was also recorded as G. elongata
Glaessner, from the Paleocene of the Gulf and Atlantic Coastal plains and of Mexico
(Loeblich & Tappan 1957a ; Olsson 1960), as G. membranacea (Ehrenberg) from the
Paleocene of the Maqfi section, Farafra Oasis, Egypt (Le Roy 1953), and as G.
compressa (Plummer) from the Paleocene of various parts of the world (see synonymy).

Globorotalia esnaensis (Le Roy)
(Pl. 21, figs. 6a-c)
1953 Globigerina esnaensis Le Roy : 31, pl. 6, figs. 8-10.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 211

1953 Acarinina pseudotopilensis Subbotina (pars) : 227, pl. 21, figs. 8a—gc ; pl. 22, figs. 2a—3¢,
non pl. 22, figs. 1a—c.

1953 Globigevina varianta Subbotina (pars) : 63, pl. 3, figs. 8a—c only ; non pl. 3, figs. 5a—7c,
toa—12c ; pl. 4, figs. 1a—3c ; pl. 5, figs. 1a—3c.

1959 Globigerina esnaensis Le Roy ; Nakkady : 461, pl. 3, figs. 2a-c.

1960 Globorotalia pseudotopilensis (Subbotina) Said ‘ 283, pl. 1, figs. 3a—c.

1960a Globorotalia wilcoxensis Cushman & Ponton ; Berggren: 97, pl. 13, figs. 3a—4¢.

1961 Globorotalia esnaensis (Le Roy) Said & Kerdany : 328, pl. 1, figs. 6a—c.

1962 Globorvotalia esnaensis (Le Roy) ; Gartner & Hay : 563-564, pl. 2, figs. 4a—c.

ered

CU]

DescripTion. Test large, globigerine, umbilico-convex, coiled in a very low
trochospire ; dorsal side slightly flattened especially in the early part ; ventral side
highly convex and strongly inflated ; equatorial periphery roughly quadrate,
distinctly lobate and coarsely spinose ; axial periphery broadly rounded ; chambers
on the dorsal side about 9, arranged in 2 dextrally coiled whorls; the initial chambers
are small, inflated, globigerine, and are masked by the surface rugosity ; the last
whorl is composed of 4 large chambers which increase so rapidly in size that the last,
which is very strongly inflated, constitutes about 4 of the test ; the first 3 chambers
in this whorl are roughly rectangular and arcuate, while the last is subglobular on
the dorsal side ; on the ventral side the chambers are 4, large, subglobular, and
strongly inflated ; sutures on dorsal side straight, radial and depressed ; on ventral
side they are straight, radial, and strongly incised ; umbilicus medium-sized,
shallow and open ; aperture an elongate, low arch, interiomarginal, extraumbilical-
umbilical ; wall calcareous, finely perforate ; surface rough, nodose or rather
coarsely spinose especially on the dorsal side and along the periphery.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter =! 0-50 mm.
Minimum diameter = 0:40 mm.
Thickness =, 0°28 mim,

MAIN VARIATION.

I. Chambers 8-10, most commonly g, arranged in 2-24 whorls which are generally
dextrally coiled, but sinistral forms also occur ; (of 470 specimens studied,
180 coiled sinistrally).

2. The last whorl is composed of 4-5 chambers, but 4 is most common.

REMARKS. Globorotalia esnaensis was first described by Le Roy, (February 1953)
as Globigerina esnaensis n.sp. from the Esna shales of the Maqfi section, Farafra
Oasis, Egypt. Subbotina (November 1953) described as Acarinina pseudotopilensis
n.sp. a form which conforms well with Le Roy’s original description and figures of
G. esnaensis, and is thus considered a junior synonym. In the same work, Subbotina
figured and described as Globigerina varianta n.sp., a form which probably belongs to
G. esnaensis (see synonymy).

Loeblich & Tappan (1957a) removed this species to the genus Globorotalia, because
of the extraumbilical-umbilical position of its aperture, but their figures are different
from the holotype of G. esnaensis.

The forms described as Globorotalia pseudotopilensis (Subbotina) by Loeblich &
Tappan (1957a), Berggren (1960a) and Reyment (1960) are different from G. esnaensis

212 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

and from the holotype G. pseudotopilensis, while that of Said (1960) probably belongs
to G. esnaensis.

Berggren (1960a) and Bermudez (1961) described as Globororalia esnaensis (Le
Roy) and Globigerina esnaensis Le Roy, respectively forms which are different from
the holotype of Le Roy. However, the former author (pl. 13, figs 3a—4c) described
as Globorotalia wilcoxensis Cushman & Ponton, forms which probably belong to
G. esnaensis. Berggren (1960b : 50-51) wrongly considered G. esnaensis figured by
Nakkady (1959) as G. soldadoensis Bronnimann, while Hillebrandt (1962 : 142-143)
included G. esnaensis in the synonymy of a form described as Globorotalia (Acarinina)
soldadoensis (Brénnimann).

Globorotalia esnaensis (Le Roy) is distinguished by its large test ; small number of
chambers ; slightly flattened dorsal side and strongly protruding ventral one ; its
quadrate, lobate, equatorial periphery and rounded axial periphery ; its radial,
depressed sutures on both sides and rough nodose surface.

The species probably evolved from G. tvibulosa Loeblich & Tappan by the increase
in the size of test and in the surface rugosity, and by the development of a more
tightly coiled test, less lobate periphery, and a much narrower aperture. On the
other hand, G. esnaensis is believed to have evolved into G. wilcoxensis Cushman &
Ponton through G. white: Weiss, by further flattening of the dorsal side, the develop-
ment of a sub-acute axial periphery in the later part of the test, and by the reduction
in the surface rugosity on the last chambers. Similarly, it has also probably involved
into G. berggrent sp. nov. as mentioned above (p. 201).

HypotyPe. P.45607.

HoRIZON AND LOCALITY. Figured specimen from sample No. 49, Gebel Owaina
section.

STRATIGRAPHICAL RANGE. The species was first described from the basal part of
the Esna shale (Unit II of Le Roy) of the Maqfi section, Farafra Oasis, Egypt ; it was
found to be abundant throughout this unit, becoming scarce higher in the section.
Le Roy tentatively considered this unit to be Lower Eocene in age while Said &
Kerdani (1961) considered it to be Landenian.

Nakkady (1959) recorded Globigerina esnaensis Le Roy throughout the Maestrich-
tian—Paleocene of the Um-E]-Ghanayem section, Kharga Oasis, Egypt. Evidently
he confused this important species with superficially similar Rugoglobigerina and
Globorotalia species, thus completely obscuring its true range.

G. esnaensis was also recorded from the Lower Tertiary of the northern Caucasus
(Subbotina 1953), the Paleocene of northern Sinai, Egypt (Said & Kenawy 1956),
the Upper Landenian—Lower Eocene of the Gulf and Atlantic Coastal Plains (Loe-
blich & Tappan 1957a, b), the Lower Eocene of Denmark (Berggren 1960a), the
? Landenian Esna shales of Luxor section, Egypt (Said 1960), the Landenian Esna
shales of the Farafra Oasis, Egypt (Said & Kerdany 1961), and from the type
Ilerdian of Spain and the Ilerdian of Mont Cayla, France (Gartner & Hay 1962).

In the Esna—Idfu region G. esnaensis (Le Roy) appears in the middle of the G.
velascoensis Zone. It floods the upper part of this zone characterizing, together with

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 213

G. aequa, the G. aequa/G. esnaensis Subzone. It crosses the Paleocene/Lower
Eocene boundary and fades out gradually in the basal Eocene. All records of G.
esnaenensis from rocks older than the upper part of the Upper Paleocene are erroneous.

Globorotalia faragi sp. nov.
(Pl. 19, figs. 4a—c)

Diacnosis. <A Globorotalia with biconvex, low trochospirally coiled test ; depres-
sed sutures ; very narrow umbilicus ; long slit-like aperture and papillose surface.

DEscrRIPTION. Test medium sized, trochospirally coiled, inflated ; dorsal side
slightly convex with the early whorls moderately raised above the level of the final
whorl ; ventral side strongly inflated ; equatorial periphery almost circular, strongly
lobate ; axial periphery rounded ; chambers on the dorsal side 16, arranged in 3
dextrally coiled whorls ; the initial ones are small, inflated, globigerine and are
followed by slightly larger, ovoid chambers ; the last whorl is composed of 5 large,
subglobular chambers which are slightly elongated in the direction of coiling and
increase slowly in size ; on the ventral side the chambers are 5, large, subglobular,
inflated and increase so slowly that they all appear to be roughly equal in size ;
sutures on the dorsal side curved, depressed in the early part, almost straight and
depressed later ; on the ventral side the sutures are straight, radial and strongly
incised ; umbilicus very small; aperture a long narrow slit, interiomarginal,
extraumbilical-umbilical, extending slightly on to the dorsal side ; wall calcareous,
perforate ; surface delicately papillose on the dorsal side, more strongly so on the
ventral.

DIMENSIONS OF HOLOTYPE.

Maximum diameter = 0-49 mms
Minimum diameter = 035 mm.
Thickness == 0:26 mm.

MAIN VARIATION.

I. Test small to medium sized, moderately to strongly inflated.

2. Coiling is mainly dextral (of 42 specimens studied, 4 coiled sinistrally).

3. The aperture is interiomarginal, extraumbilical-umbilical, but in some
specimens it extends slightly on to the dorsal side.

4. The surface is delicately to strongly papillose.

REMARKS. Globorotalia faragi is morphologically similar to G. veisst Loeblich &
Tappan from which it is distinguished by its much larger size, papillose surface and
rounded axial periphery. It differs from G. convexa Subbotina in its globular form,
larger size, non-spinose surface, rounded axial periphery and raised early whorls on
the dorsal side.

The form described here as Globorotalia cf. convexa is morphologically very similar
to the present species, but is distinguished by its flat, less globular, strongly
overlapping chambers which increase more rapidly in size, are typically crescentic
in the early stage and roughly quadrangular later.

214 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

Globorotalia faragi possibly evolved from Globigerina arabica sp. nov. by a reduction
in the size of test, number of chambers, height of the dorsal spire, and by the
development of the extraumbilical-umbilical aperture. On the other hand, G. faragi
is believed to have evolved into G. cf. convexa by a loss of globularity of the
test, and by the development of flat, crescentic, tightly coiled, strongly overlapping
chambers which become roughly quadrangular in the later part. The stratigraphical
ranges of these species support this hypothesis.

This species is named after Professor I. A. M. Farag, Cairo University.

HoLotypPe. P.45608.
PARATYPES. P.45609.

HorRIZON AND LOCALITY. Holo- and paratypes from sample No. 34, Gebel
Owaina section.

STRATIGRAPHICAL RANGE. The species ranges from the uppermost Danian to the
uppermost Paleocene, being common in the Middle Paleocene and rare in the
Upper Paleocene.

Globorotalia hispidicidaris Loeblich & Tappan
(Pl. 21, figs. 5a—c)
1957a Globorotalia hispidicidaris Loeblich & Tappan : 190, pl. 158, figs. 1a—c.

DEscriPTion. Test large, umbilico-convex, coiled in a low trochospire ; dorsal
side gently convex ; ventral side strongly protruding ; equatorial periphery circular,
moderately lobate and heavily spinose ; axial periphery angular ; the concentrated
nodes and spines along the periphery simulate a marginal pseudo-keel, although the
species is typically non-keeled ; chambers on the dorsal side 17 in number, increasing
slowly in size and arranged in 3 dextrally coiled whorls ; each whorl is lightly raised
relative to the one following ; the initial chambers are small, inflated, globigerine,
almost masked by the surface rugosity, and are followed by large, crescentic, slightly
inflated chambers ; the last whorl is composed of 6 large, roughly crescentic to
quadrangular chambers which increase slowly in size except for the last, which is
slightly smaller than the penultimate ; on the ventral side the chambers are 6, large,
high, conical, almost equal in size and meet in a relatively high umbilical shoulder ;
sutures on the dorsal side curved, depressed ; on the ventral side they are radial,
strongly incised ; umbilicus wide, deep and open ; aperture interiomarginal, extra-
umbilical-umbilical, a long, narrow slit extending to the periphery ; wall calcareous,
perforate ; surface rough, distinctly nodose and heavily spinose, with the nodes and
spines concentrated along the periphery simulating a thick, spinose, pseudo-keel.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter = 044mm.
Minimum diameter = 0 -a7aiaia
Thickness =, (0°20) mm:

REMARKS. Globorotalia hispidicidaris is distinguished by its large, heavily
spinose test ; its numerous chambers which increase slowly in size ; its gently convex

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 215

dorsal side and strongly protruding ventral side ; its high umbilical shoulder ; wide,
deep umbilicus; its curved, depressed dorsal, and radial strongly incised ventral
sutures ; its subcircular, lobate, densely spinose, equatorial periphery and angular
axial one ; and its slit-like, long, narrow aperture.

Globorotalia hispidicidaris possibly evolved from G. apanthesma Loeblich & Tappan,
by the development of the unequally biconvex test, angular axial periphery, more
densely spinose surface, a high umbilical shoulder, a narrower, deeper umbilicus, a
narrower, longer aperture, and a thick spinose pseudo-keel. On the other hand, it is
not excluded that G. hispidicidaris has evolved from G. mckannat, with forms like G.
stvabocella Loeblich & Tappan as transitional stages.

Hypotyre. P.45610.

HoRIzON AND LOCALITY. Figured specimen, from sample No. 55, Gebel Owaina
section.

STRATIGRAPHICAL RANGE. The species was first described by Loeblich & Tappan
(19574) from the Aquia formation of Virginia which they considered to be of Upper
Landenian or Sparnacian age.

In the Esna—Idfu region, G. jispidicidaris is a rare to common form in the upper-
most part of the G. velascoensis Zone (the upper part of the G. aequa—G. esnaensis
Subzone) of uppermost Palecoene age.

Globorotalia imitata Subbotina
(Pl. 17, figs. 6a—c)
1953 Globorotalia imitata Subbotina : 206-207, pl. 16, figs. 14a—16c.
1957a Globorotalia imitata Subbotina ; Loeblich & Tappan (pars) : 190-191, pl. 45, figs. 6a—c ;
pl. 54, figs. 8a—c, ? ga-c ; pl. 59, figs. 5a—c ; pl. 63, figs. 3a-c ; ? pl. 44, figs. 3a-c.
1960 Globorotalia imitata Subbotina ; Olsson : 46, pl. 9, figs. 7-9.

DESCRIPTION. Test small, coiled in a very low trochospire ; dorsal side flat in the
early part, weakly inflated later ; ventral side moderately inflated, slightly protruding
equatorial periphery subcircular, lobate ; axial periphery rounded ; chambers on
the dorsal side 14, arranged in 2 sinistrally coiled whorls ; the initial chambers are
small, globigerine, compressed and very tightly coiled ; the last whorl is composed of
6 relatively large, roughly globular and weakly inflated chambers, which increase
moderately in size except for the last which is slightly smaller than the penultimate ;
on the ventral side the chambers are 6, globular and moderately inflated ; sutures on
the dorsal side curved, depressed in the early part, almost straight, radial and
depressed later ; on the ventral side they are straight, radial and strongly depressed ;
umbilicus relatively large, shallow and open ; aperture interiomarginal, extraumbili-
cal-umbilical, a low arch bordered above by a narrow, delicate lip ; wall calcareous,
perforate ; surface smooth.

DIMENSIONS OF DESCRIBED SPECIMEN.
Maximum diameter == Or25 alin
Minimum diameter == 0°20 mm:
Thickness = o-1r mm. (of last chamber)

216 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

REMARKS. Specimens of G. imitata Subbotina from the Esna—Idfu region con-
form well with the original description and figures, although the specimen figured
here is slightly larger, has subglobular rather than oval chambers, and has more
chambers in the final whorl. However, as mentioned by Subbotina, such minor
differences fall well within the range of variation of the species.

G. wmutata was described by Subbotina as having a close resemblance both to
G. membranacea and G. compressa (Plummer). However, Subbotina’s G. membran-
acea included representatives of G. compressa, G. ehrenbergi and G. pseudomenardit,
all of which are morphologically and stratigraphically distinct from G. imitata.
The latter species is believed to have evolved from G. pseudobulloides (Plummer) by
reduction in the size of test and rate of chamber growth, by flattening of the dorsal
side and the development of a smooth test. However, it might have evolved from
G. compressa although no direct evidence was found. G. imitata probably evolved
into G. ehrenbergi Bolli, by the development of a slightly more compressed test and
a weak keel on the last chamber. Forms of G. ehrenbergi without the partially
developed keel are believed to be transitional to G. imitata.

Said (1960) and Said & Kerdany (1961) described as G. imitata Subbotina (from
the Lower Eocene Thebes limestones of Luxor and the Upper Paleocene Esna shales
of Farafra Oasis respectively) forms which are completely different from Subbotina’s
original description and figures. Said’s form was recorded as ranging through the
Lower Eocene only, whereas G. imitata was first described from the Danian and was
found to die out completely long before the Lower Eocene. Said relied on Loeblich
& Tappan’s record of G imitata from the Nanafalia formation of Alabama which they
considered as Lower Eocene, but both Bramlette & Sullivan (1961) and Gartner &
Hay (1962) assigned this formation to the Paleocene.

HypoTyPe. P.45611.

HORIZON AND LOCALITY. Figured specimen, from sample No. 7, Gebel EI-
Kilabiya section.

STRATIGRAPHICAL RANGE. The species was first described by Subbotina (1953)
from the zone of “ Rotalia-like Globorotalia’’’, Elburgan horizon, Northern Caucasus,
which she tentatively assigned to the Danian. It was also recorded from the Danian
of the Gulf and Atlantic Coastal Plains of the U.S.A., where it was found to continue
through the overlying Landenian and the so-called Lower Eocene (Loeblich &
Tappan 1957a ; Olsson 1960).

In the Esna—Idfu region G. imitata occurs as a rare to common form in the Upper
Danian (the Lower and Middle Danian being missing), and continues as a rare form
up to the basal part of the Upper Paleocene G. velascoensis Zone.

Globorotalia irrorata Loeblich & Tappan
(Pl. 23, figs. ga—c)
1957a Globorotalia ivvovata Loeblich & Tappan : 191, pl. 46, figs. 2a—c ; pl. 61, figs. 5a-c.

DESCRIPTION. Test medium sized, coiled in a low trochospire ; dorsal side almost
flat, weakly inflated ; ventral side strongly inflated ; equatorial periphery roughly

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 217

quadrate, moderately lobate ; axial periphery subrounded ; chambers on the dorsal
side about 13, arranged in 2} dextrally coiled whorls ; the initial chambers are very
small, indistinctand almost masked by the surface rugosity ; they are followed by much
large, roughly globular, compressed chambers which increase slowly in size ; the last
whorl is composed of 4 large, roughly ovoid, slightly inflated chambers which are
elongated in the direction of coiling, and increase slowly in size, except for the last
which is much smaller than the penultimate ; on the ventral side the chambers are 4,
large, globular and strongly inflated ; sutures on the dorsal side slightly curved,
depressed ; on the ventral side they are straight, radial and strongly incised ; umbili-
cus small, deep and open ; aperture a low, interiomarginal, extraumbilical-umbilical
slit ; wall calcareous, perforate ; surface heavily nodose with the nodes tapering out
in the form of thick, stout, spine-like projections especially on the ventral side and
along the periphery.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter = 50-45 0m:
Minimum diameter = (Oras Tain:
Thickness == O26. Matt,

REMARKS. Berggren (1960a) removed this species to the genus Globigerina, but
the forms figured by him are different from the type specimens of Loeblich & Tappan
(19574).

Globorotalia ivrorata is distinguished from Globigerinasoldadoensis Bronnimannbyits
larger size, more globular chambers, more rounded and lobate periphery, and extraum-
bilical aperture. It differs from Acarinina intermedia Subbotina in its quadrate outline,
chambers which increase slowly in size, and much smaller last chamber. <Acarinina
clara Khalilov (1956) is closely related to the present species, but has a higher dorsal
side, a greater number of chambers, more whorls and a densely porous surface with
short spines between the pores.

Globorotalia irrovata probably evolved from G. quadrata (White) by the
development of the heavily spinose surface, and into G. berggreni sp. nov. by the
increase in the rate of coiling and in the surface rugosity, by the slight compression of
test, the reduction in the size of the umbilicus, and by the development of the long
narrow aperture. The stratigraphical distribution of these species substantiate
this proposition although no direct evidence was recorded.

IDYPOTYPE. P.45612.

HORIZON AND LOCALITY. Figured specimen, from sample No. 51, Gebel Owaina
section.

STRATIGRAPHICAL RANGE. The species was described by Loeblich & Tappan
(1957a) from the Coal Bluff marl member of the Naheola formation, and from the
Nanafalia formation of Alabama which they considered as Upper Thanetian and
Lower Eocene respectively, although the latter is most probably of Upper Paleocene
age as well.

In the Esna—Idfu region G. ivrovata is a rare to common form in the G. aequa/G.
esnaensis Subzone of uppermost Paleocene age.

218 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

Globorotalia kilabiyaensis sp. nov.
(Pl. 17, figs. 4a=c)

Driacnosis. A Globorotalia with concavo-convex, compressed test ; lenticular,
chambers which increase rapidly in size ; radial, depressed sutures ; wide umbilicus
and almost perfectly smooth surface.

DESCRIPTION. Test medium-sized, concavo-convex, strongly compressed, coiled
in a very low trochospire ; dorsal side slightly convex, ventral side concave ; equa-
torial periphery roughly ovoid, slightly elongate, moderately lobate ; axial periphery
subrounded, compressed ; chambers on the dorsal side 13, arranged in 2 sinistrally
coiled whorls ; the initial ones are small, globigerine, compressed and increase slowly
in size ; the last whorl is composed of 44, roughly lenticular, slightly compressed
chambers which increase rapidly in size ; on the ventral side the chambers are 43,
roughly lenticular and increase rapidly in size ; sutures on the dorsal side curved,
depressed in the early part, almost straight, depressed later ; on the ventral side
they are straight, radial and strongly depressed ; umbilicus large, shallow and open ;
aperture interiomarginal, extraumbilical-umbilical, covered with a prominent,
flaring lip ; wall calcareous, perforate ; surface perfectly smooth with few, small,
delicate papillae on the ventral side of the early chambers.

DIMENSIONS OF HOLOTYPE.

Maximum diameter = 0-300 mm.
Minimum diameter = ~0°225 mm.
Thickness = 0-100 mm.

REMARKS. Globorotalia kilabiyaensis sp. nov. is distinguished from G. compressa
(Plummer) by its distinctly concavo-convex test, much wider umbilicus and
delicately papillose surface. The form described as G. compressa by Loeblich &
Tappan (19574, pl. 44, figs. ga—c) shows a slightly concave ventral side and may be
transitional between G. compressa and G. kilabiyaensts.

HoLotypPe. P.45613.
PARATYPE. P.45614.

HORIZON AND Locality. MHolo- and paratypes, from sample No. 7, Gebel El-
Kilabiya section.

STRATIGRAPHICAL RANGE. Globorotalia kilabiyaensis sp. nov. occurs in abundance
in the Upper Danian rocks of the Esna-Idfu region, immediately above the disconfor-
mity separating it from the underlying Maestrichtian strata. It ranges throughout
the Upper Danian, fading out gradually towards its top, and dying out completely
before the first appearance of G. angulata angulata, which marks the base of the
Middle Paleocene.

Globorotalia loeblichi sp. nov.
(Pl. 23, figs. 1a—c)

? 1953 Acarinina pseudotopilensis Subbotina (pars) : 227, pl. 22, figs. 1a—c ; non figs. 2a—3¢,
pl. 21, figs. 8a—oc.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 219

? 1957a Globorotalia aequa Cushman & Renz; Loeblich & Tappan (pars) : 186, pl. 59, figs.
6a—c ; pl. 64, figs. 4a—c ; ? pl. 60, figs. 3a-c ; non pl. 46, figs. 7a—-8c, pl. 50, figs. 6a-c, pl. 55,
figs. 8a—c (?).

? 1961 Globorotalia triplex (Subbotina) ; Said & Kerdany : 330, pl. 1, figs. r1a—c.

?1962 Globorotalia (Tvuncorotalia) aequa simulatilis (Schwager) ; Hillebrandt: 134-135,
pl. 13, figs. 6a—8c.

?1962 Globorotalia (Acarinina) quetra Bolli ; Hillebrandt : 144, pl. 14, figs. 3a—c.

Diacnosis. A Globorotalia with small strongly umbilico-convex test ; flat,
slightly imbricate dorsal side, and distinctly protruding ventral one ; extremely
narrow umbilicus, and high umbilical shoulder ; curved, imbricate dorsal sutures,
and radial, incised ventral ones ; crescentic chambers on dorsal side, elongated in
direction of coiling and increasing rapidly in size ; delicate marginal keel, and delica-
tely papillose surface.

DESCRIPTION. Test small, planoconvex, umbilico-convex, coiled in a very low
trochospire; dorsal side flat, slightly imbricate ; ventral side distinctly protruding ;
equatorial periphery roughly ovoid, distinctly lobate with a delicately beaded
marginal keel ; axial periphery angular, acute ; chambers on the dorsal side about 12,
rapidly increasing in size and arranged in 24 dextrally coiled whorls ; the initial
chambers are small, indistinct and almost masked by the surface rugosity ; the last
whorl is composed of 34, large, crescentic chambers, which are strongly elongated in
the direction of coiling ; the last chamber constitutes about half the test ; on the
ventral side, the chambers are 33, distinctly angular conical, strongly protruding ;
sutures on the dorsal side strongly curved, delicately beaded and very weakly raised ;
on the ventral side they are almost straight, radial and strongly depressed ; umbili-
cus extremely small, deep and open ; aperture interiomarginal, extraumbilical-
umbilical, a large, crescentic arch with a narrow delicate lip; wall calcareous perforate:
surface. delicately but distinctly papillose with the papillae decreasing gradually
towards the last chamber.

DIMENSIONS OF HOLOTYPE.

Maximum diameter = 0°30 mm.
Minimum diameter = (Oy isan,
Thickness = 0:20 mm.

REMARKS. Globorotalia loeblicht sp. nov. is morphologically similar to both
Globorotalia lensiformis Subbotina, and Globorotalia quetva Bolli. It is distinguished
from the former by its much smaller size, less tightly coiled test, fewer chambers in the
last whorl, more lobate periphery, slightly imbricate dorsal side, less developed keel,
and less rugose surface. It differs from G. quetra Bolli in its much smaller size ; flat,
imbricate dorsal side ; less lobate periphery ; delicate, non-spinose keel, more angular
axial periphery, and delicately papillose, non-spinose surface.

Loeblich & Tappan (1957a) described as G. aequa Cushman & Renz, from the
Paleocene—Lower Eocene of the Gulf and Atlantic Coastal plains of the U.S.A., and of
Mexico, forms with a marginal keel, although G. aequa does not havea keel. As can
be seen from their figures, these forms probably belong to the present species, to
G. quetra Bolli, and to other undescribed forms (see synonymy). Similarly, the form

220 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

described by Said & Kerdany (1961) as G. triplex (Subbotina) is possibly G. loeblichi
sp. nov. ; Acarinina triplex is synonymous with both Globigerina velascoensis and
G. stonet, as mentioned above. Again, although the holotype of Acarinina
pseudotopilensis Subbotina is a junior synonym of Globorotalia esnaensis (Le Roy),
the paratype figured by Subbotina (1953, pl. 22, figs. 1a—c) most probably belongs
to the present species. Hillebrandt (1962) described as Globorotalia (Truncorotalia)
aequa simulatilis (Schwager) and Globorotalia (Acarinina) quetra Bolli, forms which
probably belong to G. loeblichi.

Globorotalia loeblichi sp. nov. is believed to have evolved from G. aequa Cushman &
Renz by the development of a marginal keel, and by the reduction in the surface
rugosity and in the size of the umbilicus. On the other hand it is believed to have
evolved into G. quetra Bolli by the increase in the size of test ; by the development of
the slightly concave dorsal side, less tightly coiled test, distinctly spinose surface,
spinose keel, and by the reduction of the keel on the last one or two chambers. The
paratype figured by Bolli (19570, pl. 19, figs. 4-6) is probably a transitional stage
between G. loeblichi and G. quetra, and forms mentioned by Bolli as G. cf. quetra may
belong to G. loeblichi.

The present species is named after Dr. A. R. Loeblich, Jr.

HoLotyPe. P.45615.
PARATYPES. P.45669-70.

HORIZON AND LOCALITY. Holo- and paratypes, from sample No. 68, Gebel
Owaina section.

STRATIGRAPHICAL RANGE. Globorotalia loeblicht sp. nov. occurs in the uppermost
Paleocene G. aequa/G. esnaensis Subzone and in the Lower Eocene G. wilcosensis
Zone of the Esna—Idfu region.

Globorotalia nicoli Martin

1943 Globorotalia nicoli Martin : 27, pl. 7, figs. 3a-c.
? 1960 Globorotalia convexa Subbotina ; Olsson : 45, pl. 9, figs. 13-15.
1962 Globorotalia nicoli Martin ; Gartner & Hay : 565, pl. 11, figs. 3a—c.

REMARKS. This species is morphologically similar to both G. convexaSubbotina and
G. esnaensis (Le Roy). It differs from the former in its slightly larger size, flatter
dorsal side, fewer chambers per test and in the last whorl and in that its chambers are
more strongly elongated in the direction of coiling. It is distinguished from G.
esnaensis (Le Roy) by its smaller size, relatively compressed test, acute axial peri-
phery and less lobate equatorial one, more strongly elongated chambers in the
direction of coiling, slightly raised dorsal side and more tightly coiled test.

The forms described by Mallory (1959, pl. 30, figs. 7a-c) as G. micoli Martin are
different from Martin’s original description and figures, while those figured by him
(1959, pl. 42, figs. 4a-c) are possibly G. convexa Subbotina. Again, the forms
figured by Olsson (1960) as G. convexa Subbotina are most probably G. noicoh
Martin. Globorotalia nicoli is also morphologically similar to G. aequa Cushman &
Renz, from which it probably evolved.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 221

HypotypPe. P.45617.
HoRIZON AND LOCALITY. Hypotype from sample No. 63, Gebel Owaina section.

STRATIGRAPHICAL RANGE. G. micoli was first described by Martin (1943) from
the Paleocene-Lower Eocene Lodo Formation of California. It was also recorded
from the Lower Eocene “‘ marne bleue ”’ of Mont Cayala, France, by Gartner & Hay
(1962) who assigned it to the Ilerdian, and from the Paleocene Hornerstown forma-
tion, New Jersey coastal plain, by Olsson (1960).

In the Esna—Idfu region, G. nicoli occurs as a rare form in the uppermost Paleocene
G. aequa/G. esnaensis Subzone.

Globorotalia occlusa Loeblich & Tappan
(Pl. 20, figs. 2a—-d ; Pl. 22, figs. 4a-c)

1957a Globorotalia occlusa Loeblich & Tappan : 191, pl. 55, figs. 3a—c ; pl. 64, figs. 3a-c.
1960b Globorotalia acutispiva Bolli & Cita : 15-17, pl. 33, figs. 3a-c.

DESCRIPTION. (Specimen, Pl. 22, figs. 4a—c.) Test medium sized umbilico-
convex, coiled in a low trochospire ; dorsal side almost flat, very weakly raised
in the centre ; ventral side distinctly protruding ; equatorial periphery roughly
ovoid, very weakly lobate to almost entire, with a distinct, thin, marginal
keel ; axial periphery sharply acute ; chambers on the dorsal side about 11 in number,
arranged in 2 sinistrally coiled whorls ; the initial chambers are weakly raised, and
almost masked by the surface texture ; the last whorl is composed of 5 large, roughly
crescentic chambers, which are strongly elongated in the direction of coiling, and
increase gradually in size (however, the last chamber is broken in the figured speci-
men and the penultimate chamber is slightly smaller than the ante-penultimate) ;
on the ventral side the chambers are 5 (4+ 1 broken), large, angular, conical,
roughly triangular, distinctly protruding with their distal ends moderately decorated
with fine papillae and approaching very closely around the much narrowed umbilicus ;
sutures on the dorsal side curved, moderately raised and delicately beaded ; on the
ventral side they are radial and strongly depressed ; umbilicus very small, deep, open,
and surrounded with a small, thickened and papillose umbilical shoulder ; aperture
interiomarginal, extraumbilical-umbilical ; wall calcareous, perforate ; surface
delicately papillose in the early part, smooth later, except for the papillose umbilical
shoulder, dorsal sutures, marginal keel, and the early chambers on the ventral side
where the beads sometimes taper out in the form of delicate spines, giving the surface
a roughly hirsute appearance.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter == O-4r im.
Minimum diameter = 0-34 mm.
Thickness == 0-24 mim.

REMARKS. Globorotalia occlusa was first described by Loeblich & Tappan from
the Velasco formation of Mexico. These authors (1957a, pl. 45, figs. 7a-c, pl. 50,

222 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

figs. 4a—c), also described as G. angulata (White), forms which most probably belong
to G. occlusa.

Bolli & Cita (1960b) described as G. acutispiva a form which only differs from the
present species in being slightly more lobate : it is thus included in the synonymy.

Hillebrandt (1962) considered G. occlusa as a subspecies of G. velascoensis, but the
present study showed clearly that the two species should be considered separately in
spite of their morphological similarity.

Globorotalia occlusa is distinguished by its medium-sized, umbilico-convex test ;
weakly curved dorsal side and protruding ventral side ; its very narrow, deep
umbilicus ; papillose umbilical shoulder, thin, papillose or even hirsute keel ;
slightly rough early part ; curved, raised, delicately beaded dorsal sutures and radial
strongly depressed, ventral ones. It is believed to have evolved from G. angulata
(White) as indicated by their morphological characters and stratigraphical distri-
bution, although no direct evidence was recorded. On the other hand, G. occlusa
is morphologically somewhat similar to G. avagonensis Nuttall, which may be among
its direct or indirect descendants.

Globorotalia occlusa is also morphologically similar to G. simulatilis (Schwager),
although very little is known about this form. However, G. occlusa has a distinctly
developed marginal keel, while Schwager (1883) in his original description of Discorbina
simulatilis stated that “ the test is somewhat drawn out towards the periphery, but
in no way really keeled’’. Nevertheless, Said (1960) described as G. simulatilis
(Schwager) from the “‘ Esna shales ”’ of Luxor section, Egypt, a form with a distinctly
developed marginal keel as can be seen from his figures. This form is possibly G.
subbotinae Morozova. Said relied on his study (Said & Kerdany 1961) of supposed
topotype material of Schwager’s species, but the form figured by these authors also
has a distinct marginal keel. It was described from the Upper Paleocene G. velasco-
ensis Zone while Schwager’s holotype is from the Lower Eocene “ Libysche Stufe ”’.

Hypotypes. P.45618-109.

HORIZON AND LOCALITY. Figured specimens, Pl. 20, figs. 2a-d, Pl. 22, figs.
4a-—c, from samples No. 40 and 51 respectively, Gebel Owaina section.

STRATIGRAPHICAL RANGE. Loeblich & Tappan (1957a) described the holotype of
G. occlusa from the Paleocene Velasco formation of Mexico. They also recorded
the species from the Upper Landenian (Sparnacian) Vincentown formation of New
Jersey, Salt Mountain limestone of Alabama and the Aquia formation of Virginia.

Bolli & Cita (1960) described this species under the name G. acutispira from the G.
pseudomenardu —G. velascoensis Zones of the Paderno d’Adda section of northern
Italy which were regarded by them as Montian—Thanetian.

Hillebrandt (1962) recorded this species to range throughout his Lower, Middle
and Upper Paleocene of Austria, which he regarded as Montian, Landenian and
Ilerdian respectively, although his forms appear to be different from Loeblich &
Tappan’s original description and figures.

In the Esna—Idfu region G. occlusa appears in the Upper Paleocene G. velascoensis
Zone. It floods the basal part of this zone, the G. psewdomenardi Subzone and fades

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 223

out gradually upwards in the section, dying out completely in the overlying G.
aequa—G. esnaensis Subzone.

Globorotalia perclara Loeblich & Tappan
(Pl. 21, figs. 2a~c)

19574 Globorotalia perclava Loeblich & Tappan : 191~-192, pl. 40, figs. 7a—-c ; pl. 41, figs. 8a—c ;
pl. 42, figs. 4a—c ; pl. 45, figs. 11a—c ; pl. 46, figs. 3a—-c ; pl. 47, figs. 6a—c ; pl. 50, figs. ra—c ;
pl. 54, figs. 6a—7c ; pl. 57, figs. 3a—4c ; pl. 60, figs. 5a—c.

1960 Globovotalia perclava Loeblich & Tappan ; Olsson : 46, pl. 9, figs. 1-3.

DESCRIPTION. Test large, moderately inflated, coiled in a low trochospire ;
dorsal side almost flat, slightly imbricate in the early part, becoming gradually
inflated towards the last chamber ; ventral side moderately inflated although the
first two chambers are slightly flattened ; equatorial periphery roughly ovoid,
elongate, distinctly lobate ; axial periphery rounded ; chambers on the dorsal side 16,
arranged in 3 dextrally coiled whorls ; the initial chambers are small, slightly
flattened, increasing slowly in size and are followed by relatively larger, quadrangular
chambers which become crescentic towards the beginning of the last whorl, and
increase moderately in size ; the last whorl is composed of 6 large chambers which
are crescentic, imbricate and slightly compressed in the early part, globular and
inflated later, and increase moderately in size ; on the ventral side there are 6 large
chambers which increase gradually in size and degree of inflation ; sutures on the
dorsal side curved, depressed in the early part, becoming almost straight, radial and
strongly depressed later ; on the ventral side the sutures are straight, radial and
strongly incised ; umbilicus small, deep and open ; aperture a long, crescentic arch,
interiomarginal, extraumbilical-umbilical ; wall calcareous, perforate ; surface on
the dorsal side rough, papillose in the early part, smooth to very delicately papillose
later, heavily nodose on the ventral side.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter = 0:44 mm.
Minimum diameter == JOr32\ mm.
Thickness = 0:25 mm. (of last chamber)

REMARKS. Globorotalia perclara was first described by Loeblich & Tappan (19572)
from the Paleocene of the Gulf and Atlantic Coastal Plains. These authors also
considered the form previously described by Shifflett (1948) as Globigerina cf.
pseudobulloides Plummer, from the Aquia formation of Virginia, to belong to the
present species. The specimens figured by Berggren (1960a) as G. perclara are
completely different from the types and should be considered separately.

Globorotalia perclara is distinguished by its small to large, elongate test; its
tightly coiled, compressed early part, and globular, inflated later part; its distinctly
nodose, spinose ventral side, and almost smooth last chambers and rough early ones
on the dorsal side ; its curved dorsal sutures which are depressed in the early part,
and which become straight, radial, strongly depressed later ; its radial, strongly
incised ventral sutures ; its curved spiral suture which becomes strongly depressed
in the later part ; its narrow, deep umbilicus and its characteristic aperture.

224 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

The species is morphologically similar to G. uwncinata uncinata (Bolli) from which it
is distinguished by its radial, depressed intercameral sutures, which are curved
and depressed in G. wncinata, its roughly spinose ventral side, its less tightly coiled
test, compressed early part and inflated later part, and its wider umbilicus. Globo-
votalia uncinata was only recorded from the lower part of the Middle Paleocene while
G. perclara ranges throughout the whole Paleocene. Berggren (1960a) stated that
further study may reveal these two forms to be conspecific, but the present study
strongly substantiates their separate identity.

Globorotalia perclara probably evolved from G. tvinidadensis Bolli by the reduction
in the size of test, the flattening of the early part and the development of the surface
rugosity although no direct evidence was recorded. On the other hand, it is believed
to have evolved into G. sibaiyaensis sp. nov. by the further reduction in the size of
test, and the development of an entire, heavily spinose surface. The morphological
features and stratigraphical ranges of these species support this suggestion.

HypotyPe. P.45620.

HORIZON AND LOCALITY. Figured specimen, from sample No. 35, Gebel Owaina
section.

STRATIGRAPHICAL RANGE. The species was first described by Loeblich & Tappan
(19574) from the Danian Brightseat formation of Alabama and was reported to range
throughout the Paleocene and the Lower Eocene of the Gulf and Atlantic Coastal
Plains, U.S.A. However, the Nanafalia formation of Alabama, which they consider-
edas Lower Eocene, was regarded by Bramlette & Sullivan (1961) and Gartner & Hay
(1962) to belong to the Paleocene. The species was also recorded by Olsson (1960)
from the Hornerstown formation of New Jersey and was observed in the Noxontown
fauna by the same author.

In the Esna—Idfu region, G. perclava ranges throughout most of the Paleocene,
being common to flood in the Lower and Middle Paleocene, and rare in the Upper
Paleocene. It dies out completely in the lower part of the G. aequa—G. esnaensis
Subzone.

Globorotalia pseudobulloides (Plummer)
(Pl. 18, figs. 3a—c)

1926 Globigerina pseudobulloides Plummer : 133-134, pl. 8, figs. 9a—c.

1937) Globigevina pseudobulloides Plummer ; Glaessner : 382, pl. 4, figs. 31a—c.

1940 Globigerina pseudobulloides Plummer ; Cushman : 72, pl. 12, figs. 16a, b.

1942 Globigerina pseudobulloides Plummer ; Cushman & Todd : 43, pl. 8, figs, 3, 4.

1949 Globorotalia (Globorotalia) compressa (Plummer) ; Cushman & Bermudez: 34-35,
pl. 6, figs. 19-21.

1949 Globigerina cf. pseudobulloides Plummer ; Cushman & Stone : 57, pl. 10, fig. 15.

1951 Globigevina pseudobulloides Plummer : Cushman : 60, pl. 17, figs. 7, 8.

1953 Globigerina compressa Plummer var. compressa Plummer ; Subbotina (pars): 55,
pl. 2, figs. 3a—5c, ? figs. 2a—c, non figs. 6a-—c.

1953 Globigerina compressa Plummer var. pseudobulloides Plummer ; Subbotina : 57, pl. 2,
figs. 7a—-14C¢.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 225

1953 Globigervina varianta Subbotina (pars) : 63, pl. 3, figs. 5a—7c, 1oa—-12c; pl. 4, figs.
Ia—3c ; pl. 15, figs. 1a—3c ; non pl. 3, figs. 8a—oc.

1953 Globigerina pseudobulloides Plummer ; Hamilton : 223, pl. 31, figs. 10, 11.

1955 Globigerina pseudobulloides Plummer ; Dalbiez & Glintzboeckel (im Cuvillier e¢ al.,
1955) : 533, 534, 536, pl. 1, figs. 1a-c.

1957b Globorotalia pseudobulloides (Plummer) Bolli: 73, pl. 17, figs. 19-21.

1957 Globigerina pseudobulloides Plummer ; Troelsen (pars) : 128, pl. 30, figs. 6a—7c, non
figs. 8a—c.

1957a Globorotalia pseudobulloides (Plummer) ; Loeblich & Tappan (pars): 192, pl. 40,
figs. 3a-c, 9a-c ; pl. 42, figs. 3a-c ; pl. 43, figs. 3a-4c; pl. 44, figs. 6a—c, non figs.4, 5 ;
pl. 45, figs. 1a—2c ; pl. 46, figs. 6a—c.

1957 Globigerina pseudobulloides Plummer ; Sacal & Debourle : 55, pl. 23, fig. 2.

1957a Globigerina pseudobulloides Plummer ; Hofker ; 57, text-figs. 8a-c.

1959¢ Globigerina pseudsbulloides Plummer ; Hofker (pars) : 80-83, ? text-figs. Ia—2c, non
text-figs. 3a—5c.

1959 Globigerina pseudobulloides Plummer ; Hamilton & Rex : 791, pl. 252, fig. 3.

1959 Globigerina pseudobulloides Plummer : Nakkady : 461, pl. 3, figs. 4a—c.

1960 Globorotalia pseudobulloides (Plummer) ; Olsson: 46, pl. 9, figs. 19-21.

1960 Globorotalia pseudobulloides (Plummer) ; Bolli & Cita ; 25-26, pl. 31, figs. 4a—c.

1960b Globorotalia pseudobulloides (Plummer) ; Reyment (pars): 84, pl. 15, figs. 18a, b ;
non pl. 16, figs. 2, 3.

1960a Globigerina pseudobulloides Plummer ; Hofker (pars) : 232, text-figs. 31a—c, 33a-c ;
non figs. 26a—c.

1960d Globigerina pseudobulloides Plummer ; Hofker : 35, pl. 1, fig. A; pl. 2, fig. A.

1960g Globigeyvina pseudobulloides Plummer ; Hofker : 77-78, figs. 17a-20c, 22a-c, 23a-c,
36a—38c.

1960g Globigerina triloculinoides Plummer ; Hofker (pars) : text-figs. 21a—c, ? 24a—c, non
26a—28c.

19601 Globigerina pseudobulloides Plummer ; Hofker (pars) : 120, pl. 2, figs. 2-5, non fig. 6.

1960 Globigeyina bulloides d’Orbigny ; Vinogradov : 307, pl. 2, figs. 12a—13¢.

1961 Globigeyina pseudobulloides Plummer ; Bermudez: 1.194, 1.195, pl. 5, figs. 4a—b.

1961 Globorotalia varianta (Subbotina) ; Said & Kerdany : 330, pl. 1, figs. 4a-—c.

1961a Globigerina pseudobulloides Plummer ; Hofker : 69-71, pl. 1, figs. 2208, 2199, 2211,
2212, 2220.

1962 Globorotalia (Turborvotalia) pseudobulloides (Plummer) ; Berggren (pars) : 87-93, pl. 14,
figs. 3a—4c ; text-figs. 12 (Ia—3b ; non 4a—b ; 5a~—7)).

1962 Globorotalia (Globorotalia) pseudobulloides (Plummer) ; Hillebrandt : 124—25, pl. 12,
figs. 2a—c.

“~uU

vw

~~

DEscRIPTION. Test medium sized, globigerine, coiled in a very low trochospire ;
dorsal side inflated with the initial whorls slightly raised ; ventral side strongly
inflated ; equatorial periphery nearly ovoid and distinctly lobate ; axial periphery
broadly rounded ; chambers 15, arranged in 3 dextrally coiled whorls ; the initial
chambers are very small, inflated, globigerine and increase very slowly in size ; the
Jast whorl is composed of 44 large, globular, strongly inflated chambers, which increase
so rapidly in size that the penultimate and last chambers constitute most of the test ;
on the ventral side the chambers are 43, large, globular, strongly inflated and increase
rapidly in size ; sutures on the dorsal side curved, depressed in the early part, nearly
straight, radial and depressed later ; on the ventral side the sutures are radial and
strongly depressed ; umbilicus irregular in outline, narrow, deep and open ; aperture
interiomarginal, extraumbilical-umbilical, in the form of a large rounded opening

226 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

bordered above by a narrow delicate lip ; wall calcareous, distinctly perforate ;
surface very finely pitted.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter = 0-41 mm.
Minimum diameter = © '22 mm.
Thickness = 0:26 mm.

MAIN VARIATION.

1. Chambers 12-15, arranged in 2}~—3 whorls.

2. Coiling predominantly dextral (of 240 specimens picked at random, 62
coiled sinistrally).

3. Chambers in the last whorl 43-5, rarely 53.

4. The surface is usually finely pitted, but in some specimens the pits become
coarser.

ReMARKS. Bolli (1957b) removed this species from Globigerina to Globorotalia
because of the extraumbilical-umbilical position of the aperture. This was substan-
tiated by Loeblich & Tappan (1957a), Olsson (1960), Bolli & Cita (1960b), Reyment
(1960), Berggren (1962) and Hillebrandt (1962). The subgeneric classification
adopted by the last two authors is not followed here for reasons already explained.

G. pseudobulloides (Plummer) is distinguished by its low, trochospirally coiled,
“ slobigerine ”’ test ; its slightly raised initial spire ; its 44-5 chambers in the last
whorl which are strongly inflated and increase very rapidly in size ; its large, strongly
inflated last chamber ; strongly incised sutures and finely reticulate surface.

Subbotina (1953) confused G. pseudobulloides with Globorotalia compressa (Plum-
mer) and considered the former as a variety of the latter. However, both her
Globigerina compressa var. compressa Plummer and Globigerina compressa var.
pseudobulloides Plummer are mostly G. pseudobulloides (Plummer). Contrary to
Subbotina’s observations G. pseudobulloides and G. compressa are two distinct species.
Subbotina also described as Globigerina varianta n.sp., forms which probably belong
to G. pseudobulloides (Plummer), Globorotalia quadrata (White) and Globorotalia
esnaensis (Le Roy).

Hofker (1960g, 7) studied the orthogenetic changes in the development of G.
pseudobulloides in the type Danian, the Paleocene rocks of Denmark, and the upper-
most white chalk of Holland and Belgium. Although he confused the present
species with apparently similar Hedbergella species in the Maestrichtian rocks below
and considered it to belong to the genus Globigerina it is of interest to review his
observations.

Hofker (1960g ; 78) stated that “..... this species, beginning in the uppermost
white chalk (Skrivekridt) with knobs between the fine pores, gradually changes its
wall structure through the Danian from a pitted one towards a strongly honeycombed
one in the Paleocene clays above the greensand, indicating that those clays are of the
same age as the Midway Paleocene ”’ However, as the Lower and Middle Danian are
missing in the sections studied, it was not possible to judge the suggestions of
Hofker (1960g, 7) which were partially substantiated by Berggren (1962), that

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 227

typical G. pseudobulloides had evolved from a smooth, finely perforate test. Never-
theless, a slight tendency towards an increase in the surface reticulation of test
upwards in the section, was observed in the specimens studied.

On the other hand, G. pseudobulloides is believed to have evolved in several direc-
tions, leading to Globorotalia compressa (Plummer), G. imitata Subbotina, G. quadrata
(White), G. tvinidadensis Bolli, G. tribulosa Loeblich & Tappan and Globigerina
triloculinoides Plummer (see discussion under these species and Text-fig. 15).

HypotypPe. P.45621.

HORIZON AND LOCALITY. Figured specimen, from sample No. 38, Gebel Owaina
section.

STRATIGRAPHICAL RANGE. The species was first described from the Midway
group of Texas, which, according to Loeblich & Tappan (19574, b), is of Danian age.

All reliable records show that G. pseuwdobulloides (Plummer) ranges throughout the
Lower and Middle Paleocene with a rare occurrence in the basal part of the Upper
Paleocene. All records of the species in rocks older than the Danian or younger than
the lower part of the upper Paleocene are erroneous.

G. pseudobulloides is recorded as ranging throughout the whole Danian at its type
locality in Denmark, being common at the base, and less common towards its top
(Bronnimann 1953 ; Troelsen 1957 ; Loeblich & Tappan 19574, 6 ; Berggren 19608,
1962 and Hofker 1960g, 2).

Haynes (1955, 1956) recorded this species from the type Thanetian of England,
and it was recently identified by the writer from Thanetian samples kindly provided
by Dr. Haynes, and from samples collected by the author ; although the form
figured by Haynes (1956, pl. 17, figs. 12, 12b) as Globigerina pseudobulloides Plummer
is an Upper Cretaceous Rugoglobigerina species redeposited in the type Thanetian, as
examination of his specimens (B.M.N.H., P. 42633) has revealed.

In the Esna—Idfu region, G. pseudobulloides (Plummer) floods the Lower and
Middle Paleocene parts of the sections studied, and dies out completely in the basal
part of the Upper Paleocene G. velascoensis Zone.

Globorotalia pseudomenardii Bolli
(Pl. 17, figs. 7a-8c)

1926 Pulvinulina membranacea (Ehrenberg) ; Cushman : 608, pl. 21, fig. 10.
? 1928b Globorotalia membranacea (Ehrenberg) White : 280-281, pl. 38, figs. 1a—c.
? 1941 Globorotalia membranacea (Ehrenberg) ; Toulmin : 608, pl. 82, figs. 4, 5.
? 1944 Globorotalia membranacea (Ehrenberg) ; Applin & Applin: pl. 5, fig. 2.
?1946 Globorotalia membranacea (Ehrenberg) ; Cushman & Renz: 48, pl. 8, figs. 15, 16.
1949 Globorotalia cf. membranacea (Ehrenberg) ; Cushman & Stone: 57, pl. ro, figs. 16a, b.
1953 Globorotalia membranacea (Ehrenberg) ; Subbotina (pars) : 205, pl. 16, fig. 13, non
figs. 7-12.

19550 Globorotalia cf. membranacea (Ehrenberg) ; Weiss : 309, pl. 12, figs. 4, 5.

1955 Globovotalia membranacea (Ehrenberg) ; Dalbiez & Glintzboeckel (im Cuvillier e¢ al.,
1955) : 534, pl. I, figs. 5a—c.

1956 Globorvotalia membranacea (Ehrenberg) ; Haque: 188-189, pl. 22, figs. 3a—c.

,
,

_~ oa

228 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

1957) Globorotalia pseudomenardvi Bolli : 77, pl. 20, figs. 14-17.
21959 Globorotalia pseudomenardii Bolli; Nakkady : 462-463, pl. 4, figs. 3a-c.
1960b Globorotalia pseudomenardvi Bolli ; Bolli & Cita : 26-27, pl. 33, figs. 2a-c.
1961 Globorotalia pseudomenardii Bolli ; Said & Kerdany : 329, pl. I, figs. 5a—c.
? 1961 Globorotalia pseudomenardvi Bolli ; Bermudez : 1,298-1, 300, pl. 15, fig. 9.
? 1962 Globorotalia pseudomenardii Bolli ; Hillebrandt : 126-127, pl. 12, figs. 5a—c, 6a, b.

DESCRIPTION. (Specimen, Pl. 17, figs. 7a-c.) Test small, weakly biconvex,
compressed, coiled in a low trochospire ; dorsal side slightly raised, ventral side
moderately inflated ; equatorial periphery roughly ovoid, elongate, distinctly lobate ;
axial periphery angular, sharply acute, pinched out, with a fine, but distinct, entire
keel ; chambers, 12, arranged in 2 sinistrally coiled whorls ; the initial chambers are
small, slightly inflated, globigerine and increase slowly in size ; the last whorl is
composed of 5, roughly lenticular, weakly inflated, compressed chambers which
increase very rapidly in size ; on the ventral side, the 5, roughly lenticular chambers
are moderately inflated ; sutures on the dorsal side strongly curved, depressed ; on
the ventral side they are almost straight, radial and strongly depressed ; umbilicus
small, shallow and open ; aperture interiomarginal, extraumbilical-umbilical, a long
narrow arch covered by a delicate, flaring lip ; wall calcareous, perforate ; surface
smooth.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter = ©-30 Mim,
Minimum diameter == 0-20 mum,
Thickness = 0-14 mm. (of last chamber)

MAIN VARIATION.

1. Chambers 12-18, arranged in 2-3 whorls.

2. Coiling predominantly sinistral (of 125 specimens picked at random, 79
coiled sinistrally).

3. Chambers in the last whorl 4-6, most commonly 5.

REMARKS. This species was quite often described in the past as G. membranacea
(Ehrenberg), a nomen nudum. It is distinguished by its smooth, weakly biconvex,
compressed, elongate test ; its fine, entire keel ; distinctly acute axial periphery;
curved, depressed dorsal sutures and radial, incised, ventral ones ; its small umbili-
cus ; narrow elongate aperture, and delicate flaring lip.

Loeblich & Tappan (1957a) described as G. pseudomenardui Bolli, forms which are
completely different from the type specimens of Bolli and from the known hypotypes,
while the form described by Olsson (1960) is most probably G. emilet sp. nov.

Globorotalia pseudomenardii is believed to have evolved from G. ehrenbergi Bolli in
earliest Upper Paleocene time by the development of the entire keel, the rapidly
increasing chambers in the last whorl, and the distinctly acute, pinched-out axial
periphery ; although its evolution from G. emilei into G. woodi is not excluded.

HypotyPes. P.45622.

HorRIZON AND LOCALITY. Figured specimens, from sample No. 39, Gebel Owaina
section.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 229

STRATIGRAPHICAL RANGE. The species was first described by Bolli (19570) from
the Paleocene lower Lizard Springs formation of Trinidad, where it characterizes the
G. pseudomenardiit Zone, to which it is restricted. Bolli did not relate his faunal
zones to any classification of the Paleocene, but Bolli & Cita (1960a, b) considered the
G. pseudomenardi Zone of the Paderno d’Adda section of northern Italy to be of
Upper Montian age. Reliable records show that G. pseudomenardi is of lower
Upper Paleocene age. All records of this species from strata younger or older than
the lower Upper Paleocene (e.g. Loeblich & Tappan 1957a) are erroneous.

In the Esna—Idfu region Globorotalia pseudomenardi Bolli appears with the first
representatives of G. velascoensis velascoensis (Cushman) in the basal part of the
Globorotalia velascoensis Zone. It floods the lower part of this zone, thus defining
the G. pseudomenardi Subzone, here considered to be of lower Upper Paleocene age; it
dies out before the first appearance of G. esnaensis and G. aequa which characterize
the overlying subzone.

Globorotalia pusilla laevigata Bolli
(Pl. 17, figs. 12a—c)
19576 Globorotalia pusilla laevigata Bolli : 78, pl. 20, figs. 5-7.
1960b Globorotalia pusilla laevigata Bolli ; Bolli & Cita : 27-28, pl. 32, figs. 6a—c.
1962 Globorotalia (Globorotalia ?) pusilla laevigata Bolli; Hillebrandt: 128-129, pl. 11,

figs. 17a, b.

DEscrIPTION. Test small, roughly lenticular, coiled in a very low trochospire ;
dorsal side slightly raised, gently convex ; ventral side strongly convex, moderately
protruding ; equatorial periphery circular, slightly lobate ; axial periphery acute,
with a very thin, faintly developed, delicately beaded marginal keel ; chambers 19,
arranged in 3, sinistrally coiled whorls ; the inital ones are very small, slightly
inflated, globigerine, and are followed by relatively large, almost crescentic, over-
lapping chambers which increase slowly in size except for the last, which is often
slightly smaller than the penultimate ; the last whorl is composed of 6, large,
roughly crescentic chambers which increase slowly in size ; on the ventral side the
chambers are 6, relatively large, roughly triangular, conical, inflated, almost equal
in size ; sutures on the dorsal side strongly curved, faintly raised and very delicately
beaded ; on the ventral side they are almost straight, radial and depressed ; umbilicus
small, shallow and open ; aperture an elongated arch, covered by a prominent,
delicate lip, interiomarginal, extraumbilical-umbilical ; wall calcareous, perforate ;
surface smooth or very delicately papillose.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter =" 0°30 Tm:
Minimum diameter = 0:26 mm.
Thickness = 0-16 mm.

MAIN VARIATION.

I. Chambers 12-18, arranged in 24-3 whorls.

2. Coiling tends to be dextral (of 15 specimens picked at random, 11 coiled
dextrally).

230 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

3. The last whorl is usually composed of 5-6 chambers, but 4 or 7 are sometimes
found.

REMARKS. Globorotalia pusilla laevigata is characterized by its small, roughly
lenticular test ; strongly protruding ventral side ; acute axial periphery ; weakly
developed keel ; strongly curved, slightly raised dorsal sutures, and radial, depressed
ventral ones ; its crescentic chambers which increase slowly in size on the dorsal
side, and its triangular, conical, strongly protruding ones on the ventral ; its small
umbilicus ; characteristic aperture and smooth to delicately papillose surface.

Loeblich & Tappan (1957a : 194) mentioned that G. pusilla laevigata is very
similar and undoubtedly related to G. pseudoscitula Glaessner. However, although
they did not include it in the synonymy of the latter, they described as G. pseudo-
scitula, forms which most probably belong to G. pusilla laevigata. These authors
(pl. 45, figs. 7a-c) also described, as G. angulata (White), a form with a faintly
developed keel, which is most probably a 4-chambered G. pusilla laevigata.

As previously mentioned by Bolli (1957b) G. pusilla laevigata is believed to have
evolved from G. pusilla pusilla ; transitional stages between these two subspecies
were recorded, and their stratigraphical distribution substantiates this suggestion.

HypotyPe. P.45623.

HoRIZON AND LOCALITY. Figured specimen, from sample No. 48, Gebel Owaina
section.

STRATIGRAPHICAL RANGE. Bolli (19570) described G. pusilla laevigata, from the
Paleocene, lower Lizard Springs formation of Trinidad, where he showed it to range
through his G. pseudomenardi Zone only. It was also recorded from the same zone
of the Paderno d’Adda section of Northern Italy (Bolli & Cita r960a, 0). Hille-
brandt (1962) extended its range to cover strata which he referred to the Lower and
Middle Paleocene (Montian—Landenian) of Austria. Some of the specimens which
Loeblich & Tappan (1957)) described under G. pseudoscitula Glaessner and G.
angulata (White), from the Landenian of the Gulf and Atlantic Coastal Plains,
probably represent this subspecies.

In the Esna—Idfu region, G. pusilla laevigata appears in the basal part of the
Upper Paleocene G. velascoensis Zone. It continues as a common form in the lower
part of this zone, the G. psewdomenardiu Subzone, and fades out gradually, dying out
completely in the basal part of the overlying G. aequa/G. esnaensis Subzone.

Globorotalia pusilla mediterranica subsp. nov.
(Pl. 19, figs. 3a—-c)

Diacnosis. A Globorotalia pusilla with relatively larger, papillose test ; more
chambers and whorls ; more protruding ventral side and moderately convex dorsal
one ; roughly quadrangular last chambers on dorsal side, very narrow and very
strongly elongated in direction of coiling ; very high, angular conical chambers on
ventral side, strongly protruding from the periphery, leaving it as a thick, marginal
pseudo-keel.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 231

DEscRIPTION. Test medium-sized, unequally biconvex, coiled in a low trocho-
spire ; dorsal side moderately convex, ventral side strongly and distinctly protruding ;
equatorial periphery almost circular, moderately lobate ; axial periphery acute,
without keel, but the chambers on the ventral side are so strongly protruding that the
marginal periphery appears as if separated from this protruding mass by a very
shallow groove in the form of a thick marginal pseudo-keel ; chambers on the dorsal
side 18, arranged in 34 dextrally coiled whorls ; the initial ones are small, inflated,
globigerine, almost masked by the surface rugosity and are followed by crescentic,
elongated chambers; the last whorl is slightly lower than the preceding whorls,
and is composed of 44, long, narrow, roughly quadrangular chambers, which are
strongly elongated in the direction of coiling and increase slowly in size ; on the
ventral side the chambers are 4}, large, roughly triangular, conical, moderately
inflated and distinctly protruding ; sutures on the dorsal side curved, depressed in
the early part, very short, slightly curved and depressed later ; on the ventral side
the sutures are straight, radial and strongly incised ; umbilicus relatively small, deep
and open ; aperture interiomarginal, extraumbilical-umbilical, a narrow, long arch,
with a delicate, narrow lip ; wall calcareous perforate ; surface distinctly papillose,
especially in the early part.

DIMENSIONS OF HOLOTYPE.

Maximum diameter =. O35, mami.
Minimum diameter = 0:30) mn.
Thickness == @-20 mm.

REMARKS. Globorotalia pusilla mediterranica has all the main characteristics of
the G. pusilla group : the biconvex, strongly inflated test ; the protruding ventral
side, with its triangular, conical, high chambers ; radial, depressed ventral sutures ;
small umbilicus ; and long, narrow, arched aperture, with an occasional delicate
apertural lip. It is thus included as a subspecies of G. pusilla, although it is quite
distinct from the other two subspecies, G. pusilla pusilla and G. pusilla laevigata.
It differs from the former in protruding more on the ventral side, in having a higher
umbilical shoulder, a thick, marginal pseudo-keel, and quadrangular chambers on
the dorsal side. From the latter it is distinguished by its more convex dorsal side,
greater protrusion of the ventral surface, its thick marginal pseudo-keel, rough
surface, and the shape of the chambers on the dorsal side.

Globorotalia pusilla mediterranica is believed to have evolved from G. pusilla
pusilla, but nothing is known as yet about its evolution in younger strata, as no
morphologically similar forms have so far been described.

HoLotyrPe. P.45624.
PARATYPES. P.45625.

HORIZON AND LOCALITY. Holo- and paratypes, from sample No. 37, Gebel
Owaina section.

STRATIGRAPHICAL RANGE. Globorotalia pusilla mediterranica appears in the upper
part of the G. pusilla Subzone of upper Middle Paleocene age. It continues

232 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

as a rare to common form in the overlying G. pseudomenardiu Subzone, and dies out
in the basal part of the Upper Paleocene G. aequa/G. esnaensis Subzone.

Globorotalia pusilla pusilla Bolli
(Pl. 17, figs. 11a—c)

1957) Globorotalia pusilla pusilla Bolli : 78, pl. 20, figs. 8—ro.
1960b Globorotalia pusilla pusilla Bolli ; Bolli & Cita : 28-29, pl. 32, figs. 4a—c.
1962 Globorotalia (Globorotalia ?) pusilla pusilla Bolli ; Hillebrandt : 128, pl. 11, figs. 18a, b.

DESCRIPTION. Test small, biconvex, coiled in a low trochospire ; dorsal side
moderately convex, inflated, slightly imbricate ; ventral side convex, inflated,
moderately protruding ; equatorial periphery nearly circular, moderately lobate ;
axial periphery subacute, without keel ; chambers on the dorsal side 17, arranged in
3 dextrally coiled whorls ; the initial ones are small, inflated, globigerine, and are
followed by typically crescentic inflated, strongly imbricating chambers which
increase moderately in size ; the last whorl is composed of 5, large, typically crescen-
tic, slightly inflated, strongly imbricating chambers which are elongated in the
direction of coiling ; on the ventral side the chambers are 5, large, roughly triangular
and moderately inflated ; sutures on the dorsal side strongly curved, depressed ; on
the ventral side they are almost straight, radial and depressed ; umbilicus small,
shallow and open ; aperture interiomarginal, extraumbilical-umbilical, a long,
narrow arch, with a narrow delicate lip ; wall calcareous, perforate ; surface smooth.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter ==! 5 O°3h tan
Minimum diameter =) O26 ton.
Thickness =O bO) tain.

MAIN VARIATION.

I. Chambers 12-18, arranged in 24-3 whorls ; compressed to slightly inflated.

2. Coiling fairly random, with a tendency to be dextral (of 126 specimens picked
at random, 78 coiled dextrally).

3. Chambers in the last whorl 4-6, most commonly 5.

4. The surface is generally smooth, but a few forms with a finely hispid surface
were also recorded and are considered to be transitional to G. convexa
Subbotina.

REMARKS. Globorotalia pusilla pusilla is distinguished by its small, biconvex,
smooth test ; crescentic, imbricate chambers on the dorsal side, and triangular,
inflated ones on the ventral ; its subacute axial periphery ; curved, depressed dorsal
sutures, and radial, strongly incised ventral ones ; its small umbilicus and narrow,
long aperture.

The ancestral stock from which this species evolved is not really known. How-
ever, its evolution from forms such as G. uncinata wncinata Bolli or its descendant G.
angulata angulata (White) is possible, although no direct evidence was recorded. On
the other hand, G. pusilla pusilla is believed to have evolved in two directions ; one

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 233

leading to G. pusilla laevigata Bolli, by the slight flattening of the dorsal side, the
development of an acute axial periphery and a partially or completely developed keel ;
the other to G. pusilla mediterranica subsp. nov. by the increase in the size of test,
greater protrusion of the ventral side, the development of quadrangular chambers on
the dorsal side, the pseudo-keel and the surface rougosity. Moreover, G. convexa
Subbotina might possibly have evolved from G. pusilla pusilla by reduction in the
size of test, development of surface spines and the bulla-like last chamber.

HypotyPe. P.45626.

HORIZON AND LOCALITY. Figured specimen, from sample No. 37, Gebel Owaina
section.

STRATIGRAPHICAL RANGE. Globorotalia pusilla pusilla was first described by
Bolli (1957) from the Paleocene lower Lizard Springs formation of Trinidad, where
it characterizes the G. pusilla pusilla Zone, and continues through the lower part of
the overlying G. pseudomenardii Zone. It is also recorded from the so-called Lower
Montian of northern Italy (Bolli & Cita 1960a, b) and Montian of Austria (Hillebrandt
1962).

In the Esna—Idfu region, G. pusilla pusilla appears in the uppermost part of the
G. uncinata Subzone, and continues in the basal part of the G. pseuwdomenardiu
Subzone where it dies out completely. Between the limits of these two subzones it
floods the succession, thus characterizing the G. pusilla Subzone, of upper Middle
Paleocene age.

Globorotalia quadrata (White)
(Pl. 18, figs. 4a—c)
1928a Globigerina quadvata White : 195, pl. 27, figs. 18a, b.
1957) Globorotalia quadrvata (White) Bolli : 73-74, pl. 17, figs. 22-24.
1959 Globigerina quadvata White ; Nakkady (pars) : 461, pl. 3, figs. 3a-c.

DESCRIPTION. Test medium-sized, inflated, coiled in a very low trochospire ;
dorsal side depressed in the early part, inflated later ; ventral side more strongly
inflated ; equatorial periphery quadrate and distinctly lobate ; axial periphery
rounded ; chambers, 12, arranged in 24 dextrally coiled whorls ; the initial ones are
small, slightly inflated ; the last whorl is composed of 44 large, globular, inflated
chambers which increase rapidly in size except for the last which is slightly smaller
than the penultimate and is slightly compressed ; on the ventral side the chambers
are 44, large, globular and strongly inflated ; sutures on the dorsal side curved,
depressed in the early part, almost straight, radial and depressed later ; on the
ventral side the sutures are radial and strongly depressed ; umbilicus irregular in
outline, relatively wide, deep and open ; aperture a narrow crescentic arch, interio-
marginal, extraumbilical-umbilical ; wall calcareous, perforate ; surface of early
chambers finely cancellate, becoming smoother towards the last chamber.

DIMENSIONS OF DESCRIBED SPECIMEN.
Maximum diameter =! 10:495m0in.
Minimum diameter == ph.0226mnmi,
Thickness ==( 4O"25)anmD:

234 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

MAIN VARIATION.

1. Chambers 10-12, arranged in 2-3 whorls, generally dextrally coiled, but
sinistral forms also occur (of 108 specimens picked at random, 36 coiled
sinistrally).

2. Chambers in the last whorl 4-5.

REMARKS. Bolli (1957b) moved this species from Globigerina to Globorotalia
because of its interiomarginal, extraumbilical-umbilical aperture.

The species is distinguished by its quadrate appearance, generally small last
chamber, radially depressed sutures, and by the rough surface of its early chambers.

Globorotalia quadrata (White) has quite often been confused with Globigerina
bulloides d’Orbigny and with superficially similar Maestrichtian Rugoglobigerina and
Hedbergella species (e.g. White 1928 ; Nakkady 1959). G. quadrata is somewhat
similar to G. pseudobulloides (Plummer) from which it is distinguished by the quad-
rilateral arrangement of its chambers, its small last chamber, its centrally depressed
dorsal side, the rough surface of its early chambers and its straight, radial depressed
sutures on the dorsal side. Some of the forms described by Loeblich & Tappan
(19574, pl. 44, figs. 4, 5) as G. pseudobulloides (Plummer), are probably G. quadrata
(White).

Globorotalia quadrata (White) is believed to have evolved from G. pseudobulloides
(Plummer) into G. tvrorata Loeblich & Tappan as suggested by their morphological
features and stratigraphical distribution. However, it is not excluded that the
present species has also evolved into G. angulata angulata (White) by flattening of
the dorsal side and the development of the rough surface.

HyYpoTyPe. P.45627.

HORIZON AND LOCALITY. Figured specimen, from sample No. 7 Gebel El-
Kilabiya section.

STRATIGRAPHICAL RANGE. White (1928) in his original description of the species
stated that it is rare in the middle and upper Mendez formation of Mexico becoming
quite abundant at the very base of the Velasco and only slightly less so throughout
the lower part of the Velasco. It is quite evident that he confused Globorotalia
quadrata with similar quadrilateral Rugoglobigerina and/or Hedbergella species
in the Maestrichtian rocks below. Nakkady (1959) apparently made the same
mistake and thus recorded his Globigerina quadrata White as ranging throughout the
Maestrichtian—Danian—Montian of the Kharga Oasis, Egypt. His Montian is now
regarded as Lower Eocene.

Bolli (19576) recorded Globorotalia quadrata (White) from the lower Lizard Springs
formation of Trinidad, where it was found to range through the G. uncinata Zone to
the G. pseudomenardii Zone.

In the Esna—Idfu region, G. quadrata (White) floods the Upper Danian part of the
sections studied. It continues as an abundant to common form upwards in the
section, fading out gradually towards the basal part of the Upper Paleocene
G. velascoensis Zone where it dies out completely.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 235

Globorotalia sibatyaensis sp. nov.
(Pl. 23, figs. 6a—c)

Dracnosis. A Globorotalia with small, globular, elongate test, slightly compressed
inearly part and inflated later; heavily spinose surface ; narrow umbilicus ; radial
depressed sutures and long narrow aperture.

DESCRIPTION. Test very small, globular, slightly compressed, coiled in a very low
trochospire ; dorsal side almost flat in the early part, inflated later ; ventral side
moderately inflated ; equatorial periphery roughly ovoid, distinctly lobate and
heavily spinose ; axial periphery rounded ; chambers on the dorsal side 12, arranged
in two dextrally coiled whorls ; the initial chambers are small, inflated, globigerine,
and increase slowly in size ; the last whorl is composed of 54 relatively large, roughly
globular chambers which increase gradually in size ; on the ventral side the chambers
are 54, relatively large, subglobular, slightly inflated in the early part, more strongly
so later ; sutures on the dorsal side very slightly curved, depressed : on the ventral
side they are striaght, radial and strongly incised ; umbilicus small, shallow and open
aperture interiomarginal, extraumbilical-umbilical, a narrow, long slit extending
from the umbilicus to the periphery ; wall calcareous perforate ; surface spinose and
nodose.

DIMENSIONS OF HOLOTYPE.

Maximum diameter = /yO;29) mm:
Minimum diameter == 0-19 mm.
Thickness = 0-17 mm. (of last chamber)

REMARKS. Globorotalia sibaiyaensis sp.nov. is distinguished from G. perclara
Loeblich & Tappan, from which it is believed to have evolved, by its smaller
test, entirely and heavily spinose surface, much narrower umbilicus and long slit-like
aperture. It is distinguished from G. wncinata uncinata Bolli by its smaller size,
globular form, heavily spinose surface and radial incised intercameral sutures.
Globorotalia intermedia (Subbotina) differs from the present species in being more
robust, more inflated on the ventral side and almost flattened on the dorsal, and in
having fewer chambers which increase rapidly in size, and are strongly protruding on
the ventral side, with closely adjacent umbilical ends. Globorotalia sibaiyaensis also
appears to be morphologically similar to the holotype of the much younger G.
vugosoaculeata (Subbotina) which is distinguished by its raised initial part.

HoLotyPe. P.45628.
PARATYPE. P.45629.

HORIZON AND LOCALITY. MHolo- and paratypes, from sample No. 50, Gebel
Owaina section.

STRATIGRAPHICAL RANGE. The species occurs as a rare to common form in the
G. aequa-G. esnaensis Subzone of uppermost Paleocene age.

236 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

Globorotalia tribulosa Loeblich & Tappan
(Pl. 18, figs. 2a—c)
1957a Globorotalia tribulosa Leoblich & Tappan : 195, pl. 56, figs. 3a—c ; pl. 61, figs. 7a-c.

DeEscrIPTION. Test medium-sized, globular, inflated, coiled in a very low trocho-
spire ; dorsal side flat in the early part, inflated later ; ventral side strongly inflated ;
equatorial periphery roughly quadrate and distinctly lobate ; axial periphery
rounded ; chambers on the dorsal side about 12-14, arranged in 24 dextrally coiled
whorls ; initial chambers very small, much flattened and almost masked by the
surface rugosity ; the last whorl is composed of 4 large globular chambers which
increase so rapidly in size that the last two chambers constitute most of the test ; on
the ventral side the 4 chambers are also strongly inflated ; sutures on the dorsal side
curved, depressed in the early part, almost straight, radial and depressed later ; on
the ventral side they are radial and strongly incised ; umbilicus small, deep and open;
aperture a large, crescentic arch, interiomarginal, extraumbilical-umbilical ; wall
calcareous, perforate ; surface distinctly papillose, with the papillae sometimes
tapering out to form fine, delicate spines giving the surface a hispid appearance.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter ==. (0°40 Imm.
Minimum diameter =) O22 niin
Thickness === 0-24 ati,

REMARKS. Globorotalia tribulosa is distinguished from G. pseudobulloides (Plum-
mer), from which it probably evolved, by its rough, papillose and hispid surface.
It differs from G. esnaensis (Le Roy) in having a more globular, lobate test, chambers
which increase more rapidly in size, a characteristic large aperture and by the fact
that its surface is not as rough as that of G. esnaensis. G. tribulosa appears to be
transitional between G. pseudobulloides and G. esnaensis.

HypoTtyPe. P.45630.

HORIZON AND LOCALITY. Figured specimen from sample No. 32, Gebel Owaina
section.

STRATIGRAPHICAL RANGE. Loeblich & Tappan (1957a) described G. tribulosa
from the Nanafalia formation of Alabama and the Aquia formation of Virginia
which they considered as lower Eocene (Ypresian) and Upper Paleocene (Landenian)
respectively. However, both Bramlette & Sullivan (1961) and Gartner & Hay
(1962) considered the Nanafalia formation to be of Upper Paleocene age.

In the Esna—Idfu region G. tribulosa appears in the uppermost part of the Danian
and continues as a common form throughout the overlying Middle Paleocene. It dies
out completely in the basal part of the uppermost Paleocene, G. aequa/G. esnaensis
Subzone.

Globorotalia trinidadensis Bolli
(Pl. 18, figs. 7a-c)

1957) Globorotalia trinidadensis Bolli: 73, pl. 16, figs. 19-23.
1960b Globorotalia tvinidadensis Bolli: Bolli & Cita : 29-30, pl. 33, figs. 1a—c.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 237

DEscRIPTION. Test large, globigerine, coiled in a low trochospire ; dorsal side
nearly flat in the early part, strongly inflated in the last whorl ; ventral side strongly
inflated ; equatorial periphery subcircular to ovoid, distinctly lobate ; axial periphery
rounded ; chambers on the dorsal side 18, arranged in 3 dextrally-coiled whorls ;
the initial ones are very small and slightly inflated ; the last whorl is composed of 6
large globular, strongly inflated chambers ; on the ventral side the chambers are 6,
large, subglobular and strongly inflated, especially the penultimate one, which is
slightly shifted towards the umbilicus ; sutures on the dorsal side shghtly curved and
depressed in the early part, nearly straight, radial, strongly depressed in the last
whorl ; on the ventral side the sutures are nearly straight, radial and strongly depres-
sed ; umbilicus irregular in outline, moderately wide, relatively deep, open ; aperture
interiomarginal extraumbilical-umbilical, a narrow crescentic arch with a very thin
lip-like flap ; wall calcareous, perforate ; surface slightly papillose in the early part,
becoming smoother towards the last chamber.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter = ©-50 mim:
Minimum diameter = 0:36 mm.
Thickness = 035 mm.

MAIN VARIATION.

1. Chambers 14-18 arranged in 2-3 whorls generally dextrally coiled (of 175
specimens picked at random, 67 coiled sinistrally).

2. Chambers on the last whorl 6-7.

REMARKS. Globorotalia trinidadensis Bolli is distinguihsed from G. pseudobulloides
(Plummer) by its larger size, more numerous chambers in the final whorl, slightly
rugose surface of the early chambers and by its last chamber which is often slightly
smaller than the penultimate and is slightly compressed. It is believed to have
evolved from G. pseudobulloides (Plummer) and to have given rise to G. uncinata
uncinata Boll. This is supported by their stratigraphical ranges and by the
discovery in the present study of several transitional stages.

HyptTotyPes. P.45631-32.

HORIZON AND LOCALITY. Figured specimen, from sample No. 7 Gebel El-Kilabiya
section.

STRATIGRAPHICAL RANGE. The species was first described from the lower part
of the Paleocene ‘‘ Lower Lizard Springs formation of Trinidad”’, where it characterizes
the Globorotalia trinidadensis Zone, and continues through the lower part of the
overlying Globorotalia uncinata Zone. Bolli (19576) did not relate his faunal zones
to the European divisions of the Paleocene.

Globorotalia trinidadensis was also recorded from the Danian of the Paderno d’Adda
section of northern Italy (Bolli & Cita 1960a, b), from the Danian of the Tampico
Embayment of Mexico (Hay 1960) and from the Lower Paleocene of the Gubbio
section, Italy (Luterbacher & Premoli Silva 1962).

238 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

In the Esna—Idfu region, G. trinidadensis floods the Danian in the sections studied
and continues in the lower part of the Middle Paleocene G. angulata Zone where it
dies out completely.

Globorotalia troelseni Loeblich & Tappan
(Pl. 17, figs. 10a—c)
1957a Globorotalia troelsent Loeblich & Tappan : 196, pl. 60, figs. 4a—c ; pl. 63, figs. 5a—c.

DESCRIPTION. Test medium sized, weakly biconvex, compressed, coiled in a very
low trochospire ; dorsal side weakly inflated, with the initial chambers slightly
depressed ; ventral side slightly inflated with a depressed umbilicus at its centre
within which a portion of the earlier whorl is visible ; equatorial periphery roughly
ovoid, distinctly elongate, and moderately lobate ; axial periphery subacute with a
weakly develpoed marginal keel on the last chamber ; chambers on the dorsal side 11,
arranged in 2 dextrally coiled whorls ; the initial ones are small, very weakly inflated,
roughly globigerine and slightly depressed ; the last whorl is composed of 64 chambers
which are slightly compressed, globular in the early part, roughly lenticular, irregular,
compressed later, and which increase so rapidly in size that the last chamber consti-
tutes more than one third of the test ; on the ventral side, 8 chambers are visible ;
they are globular, slightly compressed in the early part, roughly lenticular, compres-
sed later and increase rapidly in size ; the extra 1} are seen within the umbilical
depression due to the tendency towards evolute coiling in the last whorl ; sutures on
the dorsal side slightly curved, depressed ; on the ventral side they are very gently
curved to almost straight, radial and depressed ; umbilicus very small, shallow ;
aperture interiomarginal, extraumbilical-umbilical, a narrow arch extending to the
periphery, with a small, delicate lip ; wall calcareous, perforate ; surface smooth
with few, small, scattered papillae.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter == -0"33 mm
Minimum diameter = "O-20 times
Thickness = 0-°r2 mm.

REMARKS. Loeblich & Tappan (19574) stated that “‘ This species is characterized
by its tendency to become evolute, so that the early whorls are visible from both the
spiral and umbilical sides.’’ However, it is only the last 2 or 3 chambers of the
early whorl that are visible within the umbilicus, not the whole of the whorl, other-
wise it would not be considered a true Globorotalia.

Because of this tendency towards evolute coiling in the last whorl, G. troelsent
may be considered as a link between Globorotalia and Globanomalina ; forms such
as Globanomalina eocenica (Berggren) might possibly have evolved from G. troelsent
in Lower Eocene time. On the other hand, G. tvoelseni is believed to have evolved
from G. emilei sp. nov. in Upper Paleocene time by the development of a weak keel
and the tendency towards evolute coiling in the last whorl.

The form figured as G. tvoelsent by Berggren (1960c) does not show the tendency
towards evolute coiling which is the main characteristic of this species. It may

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 239

belong to G. emilet sp.nov. or represent a transitional stage between it and G. troelsent.
This is substantiated by the stratigraphical range assigned to this species by Berg-
gren (1960c).

HypotyPe. P.45633.

HORIZON AND LOCALITY. Figured specimen, from sample No. 68, Gebel Owaina
section.

STRATIGRAPHICAL RANGE. This species was described from the Nanafalia
formation of Alabama and the upper part of the Velasco formation of Mexico, which
Loeblich & Tappan (19574) considered to be of Lower Eocene and Upper Landenian
age respectively. However, the Nanafalia formation was considered to be of
Upper Paleocene age on account of its nannoplankton (Bramlette & Sullivan 1961)
and of its planktonic Foraminifera (Gartner & Hay 1962).

In the Esna—Idfu region G. tvoelsent appears as a rare form in the upper part of the
Upper Paleocene G. velascoensis Zone. It crosses the Paleocene-Lower Eocene
boundary and continues in the overlying G. wilcoxensis Zone.

Globorotalia uncinata carinata subsp. nov.
(Pl. 10, figs. 1a—d)

Diacnosis. A Globorotalia uncinata with planoconvex test, thickened, nodose
keel, imbricate dorsal side and rougher surface.

DESCRIPTION. Test medium-sized, almost planoconvex, coiled in a very low
trochospire ; dorsal side flat, imbricate ; ventral side strongly protruding ; equatorial
periphery ovoid, distinctly lobate ; axial periphery angular with a well-developed,
very thick, heavily papillose or rather nodose keel ; chambers, as seen on dorsal side,
15, arranged in 24 dextrally coiled whorls ; the inital ones are small, inflated and
globigerine ; the last whorl is composed of 6, relatively large, almost crescentic, over-
lapping chambers, which increase slowly in size in the early part and rapidly
later ; on the ventral side the chambers are 6, relatively large, strongly protruding,
angular conical and increase rapidly in size towards the last chamber ; sutures on the
dorsal side curved, depressed in the early part, strongly curved, depressed later,
although they are marked by the thick, papillose, marginal keel as it curves on the
dorsal side encircling the periphery of each chamber ; on the ventral side the sutures
are almost straight, radial and strongly incised ; umbilicus small, deep and open ;
aperture a low arch, interiomarginal, extraumbilical-umbilical ; wall calcareous,
perforate ; surface rough, heavily papillose, with the roughness decreasing gradually
towards the last chamber ; the marginal keel is very thick, heavily papillose or even
nodose.

DIMENSIONS OF HOLOTYPE.
Maximum diameter 0-3/7:
Minimum diameter == 0240mm:
Thickness =O? Tamm

240 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

MAIN VARIATION.

1. Chambers 13-18, arranged in 2-3 tightly coiled whorls.

2. Coiling is random, with a tendency to be sinistral (of 29 specimens studied, 12
coiled sinistrally).

3. Chambers in the last whorl 5-6, rarely 7.

REMARKS. The tendency towards the development of a partial pseudo-keel was
observed in specimens of G. wncinata uncinata Bolli from the Esna—Idfu region
(e.g. Pl. 19, figs. 2a—c) and can be seen on the holotype of Bolli (19570, pl. 17, figs.
13-15). This tendency was found to lead higher in the section to forms with very
well-developed, thick, nodose keels, which are here described as G. uncinata carinata.
This new subspecies is distinguished from G. uncinata uncinata Bolli, from which it
is believed to have evolved, by its thick, nodose keel ; flat, imbricate dorsal side ;
distinctly angular, axial periphery ; angular conical chambers on the ventral side,
and rougher surface.

The marginal keel in G. wncinata carinata is very peculiar ; it is much thicker and
rougher than any known keel in the genus Globorotalia. The well-developed rugosity
does not allow one to see whether or not it is a true, imperforate keel, although it
seems quite distinct from the rest of the test.

HoLotyPe. P.45634.
PARATYPES. P.45635.

HorRIZON AND LOCALITY. Holo- and paratypes, from sample No. 36, Gebel
Owaina section.

STRATIGRAPHICAL RANGE. The subspecies occurs as a rare form in the uppermost
part of the Middle Paleocene, (the upper part of the G. pusilla Subzone), to which it
seems to be restricted.

Globorotalia uncinata uncinata Boll
(Pl. 18, figs. ta—c ; Pl. 10, figs. 2a—c)

1957) Globorotalia uncinata Bolli : 74, pl. 17, figs. 13-15.
? 1960b Globorvotalia uncinata Bolli ; Bolli & Cita : 30-31, pl. 32, figs. 5a—c, 7a-c.

DESCRIPTION. (Described specimen, Pl. 18, figs i1a—c.) Test small, almost
planoconvex, coiled in a very low trochospire ; dorsal side nearly flat, ventral side
strongly convex ; equatorial periphery subcircular to ovoid, distinctly lobate ;
axial periphery subrounded ; chambers on the dorsal side about 12-15, arranged in
2-21 sinistrally coiled whorls ; the initial chambers are small, indistinct, and are
followed by crescentic, very slightly inflated chambers ; the last whorl is composed of
6, crescentic to nearly subcircular, slightly overlapping chambers which increase
rapidly in size ; on the ventral side the chambers are 6, subangular, roughly triangular
to subrounded, inflated to strongly protruding with the inflation increasing gradually
towards the last chamber ; sutures on the dorsal side strongly curved, depressed ; on
the ventral side they are very gently curved to nearly straight, radial and strongly
depressed ; umbilicus irregular in outline, roughly stellate, very narrow, moderately
deep and open ; aperture a narrow crescentic arch, interiomarginal, extraumbilical-

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 241

umbilical ; wall calcareous, perforate ; surface covered with small scattered papillae
in the early part, becoming smoother towards the last chamber.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter = (0°300 Imm,
Minimum diameter = 0:200 mm.
Thickness = o-180 mm.

MAIN VARIATION.

1. Chambers 12-15, arranged in 2-3 tightly coiled whorls.

2. Coiling fairly random, with a tendency to be sinistral (of 32 specimens studied,
20 coiled sinistrally).

3. Chambers in the last whorl 5—7 ; 6 is most common.

REMARKS. Globorotalia uncinata includes various forms which can be assigned

to the following three groups.

(A) Forms with a small test, a flat to slightly inflated dorsal side, a subround-
ed to subangular axial periphery, and a delicately papillose surface
(Pl. 18, figs. ta—c). These are believed to have evolved from G.
pseudobulloides (Plummer) or its descendant G. trinidadensis Boll, in
Upper Danian time. Transitional stages between these forms and
typical G. pseudobulloides and/or G. trimdadensis were figured by
Bolli (19570, pl. 17, figs 16-18) and were observed in the present
study. On the other hand these forms are believed to have evolved
into G. angulata angulata (White) in early Middle Paleocene time.
Transitional stages between this group and typical G. angulata
angulata were figured by Bolli (19572, pl. 17, figs. 10-12) and have also
been observed by the present author.

(B) Forms with a relatively large test, a flat to slightly inflated dorsal side,
a rounded to subrounded axial periphery, a distinctly nodose or even
spinose surface, and a thick, partially developed pseudo-keel (Pl. 19,
figs. 2a—c). These forms are believed to have evolved from group A.
The holotype described by Bolli (1957, pl. 17, figs. 13-15) most
probably belongs to this group; it shows clearly the partially
developed pseudo-keel, although Bolli did not mention it in his
description.

Slightly higher in the section, members of this group were found to
pass gradually into group C.

(C) Forms with a medium-sized test, a flat, moderately to distinctly
imbricate dorsal side, a strongly protruding ventral side, an acute
axial periphery, an entire, thick, nodose keel, and a very rough,
papillose surface.

The first two groups, although differing in surface texture, were found to occur
together and to have almost the same stratigraphical range. They probably
represent the end members of one and the same species population of which Bolli’s
holotype is a central form. They are thus both grouped under G. uncinata uncinata

242 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

Bolli, to distinguish them from the related but stratigraphically younger forms of the
third group described here as G. uncinata carinata subsp. nov.

G. uncinata uncinata Bolli is distinguished by its flat to slightly inflated dorsal
side ; protruding ventral side ; rounded to subangular axial periphery ; curved,
depressed dorsal sutures and radial, incised ventral ones ; its crescentic, slightly
overlapping chambers on the dorsal side ; small, open umbilicus ; and delicately
papillose to roughly nodose surface.

Bolli & Cita (19606) described as G. wncinata Bolli, specimens which, most probably
are transitional between this species and G. angulata angulata (White).

Hillebrandt (1962) included G. uncinata Bolli in the synonymy of G. inconstans
(Subbotina). However, G. znconstans differs from G. uncinata in its rounded axial
periphery, almost straight dorsal sutures, and smooth, very finely pitted surface.
It may represent a transitional stage between G. trinidadensis and G. uncinata
uncinata.

HypotyPes. P.45636-37.

HORIZON AND LOCALITY. Figured hypotypes (Pl. 18, figs. 1a—c) from sample
No. 34 ; (Pl. r9, figs. 2a—c) from sample No. 35, Gebel Owaina section.

STRATIGRAPHICAL RANGE. The subspecies was first described from the Paleocene
lower Lizard Springs formation of Trinidad, where it was found to characterize the
Globorotalia uncinata Zone, and to continue through the overlying G. pusilla pusilla
Zone.

In the Esna—Idfu region, it is common in the Upper Danian, and continues as
common to abundant in the lower part of the Middle Paleocene G. angulata Zone,
characterizing the G. uncinata Subzone. It continues as a rare form in the over-
lying G. pusilla Subzone where it dies out completely.

Globorotalia velascoensis caucasica Glaessner
(Pl. 19, figs. 6a—c)

1937a Globorotalia avagonensis Nuttall var. caucasica Glaessner : 31, pl. 1, figs. 6a—c.

? 1953 Globorotalia velascoensis (Cushman) ; Hamilton (pars) : 231, pl. 30, figs. 16-18, non
fig. 23 ; non pl. 31, figs. 24, 28-31.

DeEscriPTION. Test large, planoconvex, strongly umbilico-convex, coiled in a very
low trochospire ; dorsal side flat although some of the chambers are weakly inflated
and slope gently towards the depressed sutures, giving the surface, in places, a
weakly undulating appearance ; ventral side distinctly protruding ; equatorial
periphery circular, strongly lobate, with a well-developed, broad, thick, heavily
beaded keel ; axial periphery distinctly acute ; chambers on the dorsal side 13,
arranged in 2 dextrally coiled whorls ; the initial ones are relatively large, almost
indistinct and very weakly raised ; the last whorl is composed of 63 large chambers
which are typically crescentic in the early part, roughly trapezoidal later, and increase
slowly in size except the last one, which is smaller than the penultimate ; on the
ventral side the chambers are 64, large, angular conical and distinctly protruding
with their distal ends thickened to form an everted collar surrounding the umbili-

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 243

cus ; sutures on the dorsal side curved, raised and beaded in the early part, almost
straight, radial, depressed and beaded in the later part ; on the ventral side the
sutures are radial and strongly incised ; umbilicus large, deep, open and crowned
with a thick, beaded, everted collar ; aperture interiomarginal, extraumbilical-
umbilical ; wall calcareous, perforate ; surface smooth except for the heavily
beaded keel, dorsal sutures and umbilical collar.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter = 0-66 mm.
Minimum diameter = O52. mm.
Thickness = 0-28 mm.

REMARKS. Globorotalia velascoensis caucasica was first described by Glaessner
(19374) as a variety of G. aragonensis Nuttall. Glaessner included in the synonymy
of his new variety the form previously described by Subbotina (1936a) as Globorotalia
velascoensis (Cushman) var. avagonensis Nuttall which was later reconsidered by
Subbotina (1953) as G. velascoensis (Cushman).

Grimsdale (1951 : 471), Subbotina (1953 : 217-218) and Berggren (1960d : 110-
111) considered Glaessner’s variety to fall well within the range of variation of
G. velascoensis (Cushman). On the other hand, Reiss (1957) followed Glaessner in
considering this form as a variety of G. avagonensis, which he regarded as a Trunco-
rotalia. However, the present study showed that Glaessner’s variety is more closely
related to G. velascoensis than to G. avagonensis, and that its morphological features
and stratigraphical distribution warrant its separation as a distinct subspecies. It
is distinguished from G. velascoensis velascoensis (Cushman) by its much larger test ;
wider umbilicus ; circular, distinctly lobate equatorial periphery ; much thickened,
heavily beaded, broader keel ; and by the roughly trapezoidal shape of its last
chambers on the dorsal side.

The form figured by Hamilton (1953, p . 30, figs. 16-18) as G. velascoensis (Cush-
man) may belong to the present subspecies, but that figured by Sjutskaya (1956) as
G. aragonensis var. caucasica is different from the holotype and from the form here
figured.

Globorotalia velascoensis caucasica probably evolved from G. velascoensis velasco-
ensis (Cushman) as it appears slightly later in the section. However, the evolution-
ary history of this subspecies could not be easily followed because of its rare occur-
rence in the samples studied.

HypotyPe. P.45638.

HORIZON AND LOCALITY. Figured specimen, from sample No. 41, Gebel Owaina
section.

STRATIGRAPHICAL RANGE. G. velascoensis caucasica was recorded by Glaessner
(1937a) from what he described as the Lower Eocene of northwestern Caucasus.
It was also recorded by Sjutskaya (1956) as occurring in what she described as Middle
Eocene (Lutetian) of the central Sub-Caucasus, although her figures are different
from those of Glaessner. However, analysis of recent Soviet work by Berggren
(1960d) led him to conclude that “...the strata in which they occur cannot be

244 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

considered to belong to the Middle Eocene (Lutetian) because of the absence of such
typically developed forms as Hantkenina, Truncorotaloides and Globigerapsis,
among others’’. He also stated that the species population recorded from these
strata are indicative of an Upper Paleocene-lowermost Eocene age as recognized
elsewhere. On the other hand, Reiss (1957) argued for a Lower-Middle Eocene age
for the present subspecies, but as he gave neither figure nor description, it is impos-
sible to know what he meant by Tvuncorotalia aragonensts caucasica.

In the Esna—Idfu region, G. velascoensis caucasia occurs as a rare form in the
lower part of the Upper Paleocene G. velascoensis Zone, the G. pseudomenardu
Subzone.

Globorotalia velascoensis parva Rey
(Pl. 20, figs. 4a—d)

1953 Globorotalia velascoensis (Cushman) ; Hamilton (pars) : 231, pl. 31, figs. 24, 28, 29,
non figs. 30, 31 non pl. 30, figs. 16-18.
1955 Globorotalia velascoensis (Cushman) var. parva Rey : 209, pl. 12, figs. ra—b.
1960b Globovotalia velascoensis parva Rey ; Bolli & Cita : 32-33, pl. 33, figs. 5a-c.
21961 Globorvotalia (Tvuncorotalia) acuta Toulmin ; Kipper : 257, pl. 16, figs. 3a-c.
? 1963 Globovotalia acuta Toulmin ; Aubert: 54-55, pl. 1, figs. 3a-c.

DESCRIPTION. Test large, planoconvex, umbilico-convex, coiled in a very low
trochospire ; dorsal side flat ; ventral side distinctly protruding with a high umbilical
shoulder and thick, beaded umbilical flange or collar ; equatorial periphery ovoid,
distinctly lobate with a well-developed, broad, thick, heavily beaded marginal keel ;
axial periphery strongly acute ; chambers on the dorsal side 9, arranged in 2 dextrally
coiled whorls, increasing slowly in size in the early part and very rapidly later ; thus
the last whorl constitutes most of the test and the last chamber about one-third of it ;
the initial chambers are small, indistinct and very weakly raised ; the last whorl is
composed of 4 large, typically crescentic chambers ; on the ventral side the chambers
are 4, large, angular conical and strongly protruding, with their distal ends much
thickened, beaded and surrounding the umbilicus in the form of an umbilical flange
or collar ; sutures on the dorsal side curved, raised, much thickened and heavily
beaded ; on the ventral side they are radial and strongly depressed ; umbilicus small,
very deep, open and crowned with a thick, beaded collar ; aperture a narrow, long
arch, interiomarginal, extraumbilical-umbilical ; wall calcareous, perforate ;
surface generally smooth with a few scattered papillae, except for the keel, dorsal
sutures and umbilical collar, which are heavily papillose.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter = 0-60 mm.
Minimum diameter = 0-48 mm.
Thickness == (0290; mm:

REMARKS. Globorotalia velascoensis parva was first described by Rey (1955) as a
variety of G. velascoensis (Cushman). Gartner & Hay (1962) raised this variety
to subspecific rank, a step which is strongly supported by this study, although their
figures are different from the holotype of Rey and from the present hypotypes.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 245

G. velascoensis parva differs from G. velascoensis velascoensis in having fewer cham-
bers per test (7-94), and fewer chambers in the last whorl (33-44) ; these are typically
crescentic, much larger and increase much more rapidly in size as added. _ It is also
distinguished by its slightly narrower umbilicus and distinctly lobate periphery.

Rey’s holotype is not clearly figured, lacks the side view, and is incompletely
described. However, he stated that the variety only differs from the central type
in that the number of chambers is reduced to 3, 4 or 5 in the last whorl. This
confirms its identity with the present subspecies, although forms with 5 chambers
are here considered to belong to the central type.

Bolli & Cita (1960b) studied paratypes of G. velascoensis parva from Morocco and
hypotypes from northern Italy, and their figured form conforms well with the
specimens here studied.

Kupper (1961) described as G. (T.) acuta Toulmin, a form which appears to be
G. velascoensis parva Rey.

Aubert (1963) described as G. velascoensis var. parva from the Paleocene of
Morocco, a form which most probably belongs to G. occlusa Loeblich & Tappan.
However, he confused the latter species with superficially similar forms and thus
extended its range to the Lower Lutetian. On the other hand, he described as
G. acuta Toulmin, which he restricted to the Paleocene only, a form which most
probably belongs to the present subspecies.

Globorotalia velascoensis parva was lumped in the past with G. velascoensts velasco-
ensis (Cushman) although their morphological features and stratigraphical distribu-
tion warrant their separation. Hamilton (1953), for example, figured under G.
velascoensis (Cushman), forms which represent the central type and also its two
subspecies (see synonymy).

G. velascoensis parva Rey is believed to have evolved from G. velascoensis velasco-
ensis (Cushman) as suggested by their morphological features and stratigraphical
ranges.

HypotyPe. P.456309.

HORIZON AND LOCALITY. Figured specimen, from sample No. 41, Gebel Owaina
section.

STRATIGRAPHICAL RANGE. The subspecies was first described by Rey (1955)
from the Paleocene of Morocco, and was recorded (as G. acuta) from the Paleocene of
the same country by Aubert (1963), who wrongly extended its range to the Lower
Lutetian. It was also recorded from the Mid-Pacific seamounts (Hamilton 1953),
the Paleocene of Italy (Bolli & Cita 1960a, b ; Luterbacher & Premoli Silva 1962 ;
and Premoli Silva & Palmieri 1962), and from the Paleocene of Vienna Basin (Ktipper
1961).

In the Esna—Idfu region G. velascoensis parva appears in the lower part of the
Upper Paleocene G. velascoensis Zone, shortly after the first appearance of G. velasco-
ensis velascoensis. It floods this zone together with the central type, but fades out
gradually upwards in the section dying out completely in the G. aequa—G. esnaensis
Subzone.

246 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

Globorotalia velascoensis velascoensis (Cushman)
(Pl. 20, figs. 3a-d ; Pl. 21, fig. 3)

1925 Pulvinulina velascoensis Cushman : 19, pl. 3, figs. 5a-c.

19266 Pulvinulina velascoensis Cushman ; Cushman : 608, pl. 21, fig. 9.

1927a Globorotalia velascoensis (Cushman) Cushman (pars) : 169, pl. 27, fig. 8, ? fig. 7, non
fig. 9.

1928b Globorotalia velascoensis (Cushman) ; White : 281, pl. 38, figs. 2a—c.

1932 Globorvotalia velascoensis (Cushman) ; Cushman & Jarvis : 51, pl. 15, figs. 8a—c.

1939c Globorotalia crater Finlay ; Finlay : 29, figs. 157, 162, 163.

1946 Globorotalia velascoensis (Cushman) ; Cushman : 153, pl. 63, fig. 6.

1946 Globorotalia velascoensis (Cushman) ; Cushman & Renz: 47, pl. 8, figs. 11, 12.

1947 Globorotalia velascoensis (Cushman) ; Subbotina : 123-127, pl. 7, figs. 9-11; pl. 9,
figs. 21-23.

1949 Globorotalia (Truncorotalia) velascoensis (Cushman) ; Cushman & Bermudez: 41-42,
pl. 8, figs. 4-6.

1951 Globorotalia velascoensis (Cushman) ; Nakkady (pars) : 54-55, pl. 1, fig. 6.

1953 Globorotalia velascoensis (Cushman) ; Hamilton (pars) ; 231, pl. 30, figs. 16-18, (non
fig. 23), pl. 31, fig. 24, ? fig. 30 (non figs. 28, 29, 31).

1953 Globorotalia velascoensis (Cushman) ; Subbotina (pars) : 216-219, pl. 19, figs. Ia—2c,
? figs. 3a—4c.

1955 Tvuncorotalia velascoensis (Cushman) Dalbiez & Glintzboeckel (tm Cuvillier e¢ al.) : 533,
pl. 2, figs. 8a—c.

1956 Globorotalia velascoensis (Cushman) ;

1957) Globorotalia velascoensis (Cushman) ; Bolli : 76-77, pl. 20, figs. 1-3, ? fig. 4.

1957a Globorotalia velascoensis (Cushman) ; Loeblich & Tappan : 196-1097, pl. 64, figs. 1a—2c.

1957 Globorotalia velascoensis (Cushman) ; Sacal & Debourle : 64, pl. 29, figs. 7-9.

1958 Globorotalia cratey Finlay ; Hornibrook : 33, pl. 1, figs. 3-5.

1959 Globorotalia velascoensis (Cushman) ; Hamilton & Rex: 794, pl. 252, figs. 18-20.

1960 Globorotalia velascoensis (Cushman) ; Bolli & Cita : 31-32, pl. 33, figs. 7a-c.

1961 Globovotalia velascoensis (Cushman) ; Said & Kerdany : 330, pl. 1, figs. 10a-—c.

? 1962 Globovotalia (Tvuncorvotalia) velascoensis velascoensis (Cushman) ; Hillebrandt: 139,

pl. 13, ? figs. 16, 17 ; non figs. 18-21.

1963 Globorotalia velascoensis (Cushman) ; Aubert (pars) : 53-54, pl. I, figs. 1a—c.

Haque : 181-182, pl. 24, figs. 2a, b.

DESCRIPTION. (Described specimen PI. 20, figs 3a—-d). Test large, planoconvex,
umbilico-convex, coiled in a very low trochospire ; dorsal side flat, ventral side
strongly protruding ; equatorial periphery subcircular, lobate, with a distinct,
broad, delicately beaded keel ; axial periphery angular, distinctly acute ; chambers
on the dorsal side 16, arranged in 24 sinistrally coiled whorls ; the initial ones are
small, globigerine, compressed and are followed by typically crescentic chambers
which increase slowly in size ; the last whorl is composed of 6 large, nearly crescentic
to roughly quadrangular chambers which increase moderately in size ; on the ventral
side the chambers are 6, large, angular conical and strongly protruding, with a
papillose everted collar decorating their distal ends and surrounding the umbilicus ;
sutures on the dorsal side curved, slightly raised and delicately beaded ; on the ven-
tral side they are straight, radial and strongly depressed ; umbilicus roughly hexago-
nal in outline, wide, deep, open and surrounded by a thick beaded, everted collar,
aperture a low arch, interiomarginal, extraumbilical-umbilical, with a narrow,
delicate lip ; wall calcareous, finely perforate ; surface smooth, except for the keel,
dorsal sutures and umbilical collar, which are distinctly papillose.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 247

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter = 0:53/mm.
Minimum diameter == hec42-mm:
Thickness == 0-26'mim:

MAIN VARIATION.

1. Chambers 12-18, arranged in 24-3 whorls, generally sinistrally coiled (of 750
specimens picked at random, 56 coiled dextrally).

2. The last whorl is composed of 5-9 chambers, but 6-7 is most common.

REMARKS. Globorotalia velascoensis velascoensis was first described by Cushman
(1925) as Pulvinula velascoensis n.sp. from the Velasco formation of Mexico. Cush-
man (1927) erected Globorotalia as a new genus in which he included Pulvinulina
velascoensis. Cushman & Bermudez (1949) split the genus Globorotalia into three
subgenera, and considered G. velascoensis to belong to the subgenus Tvuncorotalia.
Dalbiez & Glintzboeckel (in Cuvillier et. al., 1955) followed by Said & Kenway (1956)
raised Tvuncorotalia to generic rank, without giving any reason, and considered
G. velascoensis to be a Truncorotalia. Bermudez (1961) considered this species to
belong to Pseudogloborotalia Haque, which is a poorly defined genus and may be, in
part, a junior synonym of Globorotalia Cushman. Hillebrandt (1962) assigned G.
velascoensis to the subgenus Tvuncorotalia, and included G. occlusa Loeblich & Tappan
as a subspecies of it. However, as mentioned above, the subgeneric classification of
the genus Globorotalia is best avoided as most forms grade imperceptibly into one
another and no sharp lines of demarcation can be drawn. Again, although G.
occlusa is morphologically rather similar to G. velascoensts, their differences are too
great for them to be included in the same species.

The present study showed that G. velascoensis (Cushman) includes three distinct
subspecies, namely :

Globorotalia velascoensis velascoensis (Cushman).
Globorotalia velascoensis caucasica Glaessner.
Globorotalia velascoensis parva Rey.

Subbotina (1936) considered G. avagonensis Nuttall to bea variety of G. velascoensis,
and described as G. velascoensis (Cushman) var. avagonensis Nuttall, a form which
she later (Subbotina 1953 : 217-218) reconsidered as G. velascoensis (Cushman).
Glaessner (1937a) used Subbotina’s form as a basis for a new variety which he
named G. avagonensis Nuttall var. caucasica. However, this was found to be more
closely related to G. velascoensis than to G. aragonensts, and is thus included here as
a subspecies of the former, although both Grimsdale (1951) and Subbotina (1953)
considered it to be synonymous with Globorotalia velascoensis velascoensis.

Finlay (1939a) described as G. crater n.sp. from the Heretaungan stage of New
Zealand, a form which was described as “. . . like avagonensis . . . but has only
four or five chambers per whorl, a sharp keel, and a practically flat top”’, but no
figure was given until later (Finlay 1939c). These later figures were described by
Hornibrook (1958) as being of specimens from older beds and therefore not typical.
However, the figures given by Hornibrook (pl. 1, figs. 3-5) as G. crater Finlay con-

248 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

form well with G. velascoensis velascoensis (Cushman) although the ventral side is
more protruding. Variation in the degree of protrusion of the ventral side in
G. velascoensis velascoensis is clearly documented in the present study (e.g. Pl. 21,
fig. 3) and proves G. crater Finlay to bea junior synonym. Examination of topotypes
of G. crater Finlay, kindly sent to the present author by Drs. N. de B. Hornibrook
and G. Jenkins of the New Zealand Geological Survey, showed its identity with
G. velascoensis velascoensis (Cushman) in spite of minor differences which fall well
within the range of variation of the latter.

Haynes (1955, 1956) described as Globorotalia velascoensis (Cushman) aff. var.
acuta (Toulmin), from the type Thanetian of England, a reworked Upper Cretaceous
Globotruncana species. This record of Haynes was used by various authors (e.g.
Loeblich & Tappan 1957a, b ; Bolli & Cita 19602, b ; etc.) as a basis for considering
the G. velascoensis Zone to be of Thanetian age. However, Globorotalia velascoensis
(Cushman) was neither observed in the collection of Dr. Haynes, nor in the various
type Thanetian samples, recently collected by the present author.

Bolli (19570) included G. acuta Toulmin in the synonymy of G. velascoensis (Cush-
man), while Loeblich & Tappan (1957a) considered them separately.

Globorotalia velascoensis velascoensis (Cushman) is distinguished by its large,
planoconvex, strongly umbilico-convex test ; its characteristic umbilical collar ;
well-developed, beaded keel ; curved, raised, beaded, dorsal sutures and radial,
incised ventral ones ; its smooth surface ; large, deep umbilicus and characteristic
aperture. It is believed to have evolved from G. angulata abundocamerata Bolli into
its two other subspecies as well as into G. bollit sp. nov. and G. formosa gracilis Bolli.
This is substantiated by the morphological characters and stratigraphical distribution
of these forms, and by the occurrence of several transitional stages.

Hypotypes. P.45640-41.

HORIZON AND LOCALITY. Figured specimens, Pl. 20, figs. 3a—-d, from sample No.
41, and Pl. 21, fig. 3, from sample No. 37, Gebel Owaina section.

STRATIGRAPHICAL RANGE. Globorotalia velascoensis velascoensis (Cushman) is one
of the finest known Upper Paleocene index fossils. It has been recorded from
practically every part of the world where rocks of this age have been studied. It
characterizes and is restricted to the G. velascoensis Zone (uppermost Paleocene),
although some authors have wrongly extended its range to the Middle Eocene, and
others have considered the zone to fall entirely within the Lower Eocene. The
dispute over the stratigraphical position of the zone does not lessen the value of
G. velascoensis in stratigraphical correlation, although misidentification of the species
and confusion with other species has thrown some doubt on its true stratigraphical
range. Nevertheless, all reliable records show that G. velascoensis velascoensis
(Cushman) is restricted to the Upper Paleocene, and that records of this species from
older or younger strata are erroneous.

In the Esna—Idfu region, G. velascoensis velascoensis floods the upper part of the
Paleocene, constituting a distinct faunal zone, the G. velascoensis Zone. The first

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 249

appearance of G. velascoensis velascoensis (Cushman) is used to mark the base of the
Upper Paleocene, while its complete disappearance marks the dawn of the Eocene.

Globorotalia whitei Weiss
(Pl. 23, figs. 3a—c)

1928 Globigevina cyvassafoymis Galloway & Wissler ; White : 193, pl. 27, figs. 14a—c.
1935 Globorotalia crassaformis (Galloway & Wissler) Nuttall : 130, pl. 15, figs. 21, 29.
1955a@ Globovotaha white: Weiss : 18, pl. 6, figs. 1-3.
19550 Globorotalia whitei Weiss ; Weiss : 308, pl. 1, figs. 29, 30.
19570 Globorotalia wilcoxensis Cushman & Ponton ; Bolli: 79, pl. 19, figs. 7-9.
1959 Globorotaha whitei Weiss ; Hamilton & Rex : 794, pl. 253, figs. 1, 2.

DEscRIPTION. Test medium-sized, planoconvex, strongly umbilico-convex,
coiled in a very low trochospire ; dorsal side very weakly inflated or almost flat ;
ventral side strongly inflated and distinctly protruding ; equatorial periphery roughly
ovoid, distinctly lobate ; axial periphery bluntly angular ; chambers on the dorsal
side about 9 in number, arranged in 2 dextrally coiled whorls ; the initial chambers
are small, globular, compressed, and almost masked by the surface rugosity ; the last
whorl is composed of 4, large, roughly ovoid chambers which increase rapidly in size,
and are elongated in the direction of coiling ; on the ventral side the chambers are 4,
large, subglobular in the early part and roughly ovoid later, strongly inflated and
increase rapidly in size ; sutures on the dorsal side, short, slightly curved and depres-
sed ; on the ventral side they are long, straight, radial and strongly incised ; umbilicus
small, deep and open with the ventral sutures radiating from it in an X-shaped
pattern ; aperture interiomarginal, extraumbilical-umbilical ; wall calcareous,
perforate ; surface distinctly papillose or even nodose, with the nodes sometimes
tapering out to form stout, spine-like projections, especially along the periphery.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter == (Or30 Ma,
Minimum diameter ==, 10°30 10m:
Thickness = @*26 mtn.

REMARKS. Globorotalia white: was described by White (1928) and Nuttall (1935)
as Globigerina crassaformis Galloway & Wissler and as Globorotalia crassaformis
(Galloway & Wissler) respectively. However, G. crassaformis is a Pleistocene form
which is completely different from the present species.

Boll (19570) described as G. whiter Weiss, from the lower Lizard Springs formation
of Trinidad, forms which are different from the original description and figures of
Weiss. On the other hand, he described as G. wilcoxensis Cushman & Ponton a form
which most probably belongs to G. whitez.

Globorotalia white: is distinguished by its medium-sized, umbilico-convex test ;
its small number of chambers per test and in the last whorl, subangular axial
periphery, narrow umbilicus, X-shaped ventral sutures and very rough surface.
It is believed to have evolved from Globorotalia esnaensis (Le Roy) by the flattening
of the dorsal side, the development of the subangular axial periphery, and the
change of the surface spines into stout knobs. It is also believed to have evolved into

250 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

G. wilcoxensis Cushman & Ponton by the development of the sharply acute axial
periphery of the last chamber, and by the increase in surface rugosity.

HypotyPe. P.45642.

HoRIZON AND LOcALITy. Figured specimen, from sample No. 55, Gebel Owaina
section.

STRATIGRAPHICAL RANGE. The species was described by Weiss (19554, 6) from
the Paleocene and Lower Eocene of northwestern Peru. It was previously recorded
by White (1928) from the Tampico Embayment of Mexico, where he described its
range as being Upper Cretaceous—Paleocene. He certainly confused it with
superficially similar Globotruncana or Hedbergella species in the Upper Cretaceous
rocks below, and thus obscured its range. G. white: was also recorded from the Lower
Eocene of Venezuela (Nuttall 1935), the Lower Eocene Globorotalia rex Zone of the
upper Lizard Springs formation of Trinidad (Bolli 19576) and from the lowermost
Eocene of the Sylvania guyot, Mid-Pacific (Hamilton & Rex 1959).

In the Esna—Idfu region G. whitet occurs as a common to abundant form in the
uppermost Paleocene G. aequa—G. esnaensis Subzone. It crosses the Paleocene—
Lower Eocene boundary and dies out in the overlying G. wilcoxensis Zone.

Globorotalia wilcoxensis Cushman & Ponton
(Pl. 23, figs. 5a—c)

1932 Globorotalia wilcoxensis Cushman & Ponton : 71, pl. 9, figs. 1oa—c.

1939 Globorotalia wilcoxensis Cushman & Ponton ; Cushman & Garrett : 88, pl. 15, figs. 21, 22.
1944 Globorotalia wilcoxensis Cushman & Ponton ; Cushman: 15, pl. 2, figs. 14, I5.

1948 Globorotalia wilcoxensis Cushman & Ponton ; Cushman & Todd : 36, pl. 6, figs. 24, 25.
1948 Globorotalia wilcoxensis Cushman & Ponton ; Shifflett : 73, pl. 40, figs. 20-22.

1949 Globorotalia (Tvuncorotalia) wilcoxensis Cushman & Ponton ; Cushman & Bermudez :

39, pl. 7, figs. 16-18.
1953 Globovotalia wilcovensis Cushman & Ponton ; Hamilton: 231, pl. 32, fig. 7.
1955a@ Globorotalia wilcoxensis Cushman & Ponton ; Weiss : 19, pl. 6, figs. 7-9.
19550 Globorotalia wilcoxensis Cushman & Ponton ; Weiss : 308, pl. I, figs. 24, 25.
1958 Globovotalia wilcovensis Cushman & Ponton ; Asano: 46, pl. 12, figs. 4a—c.

DESCRIPTION. Test medium-sized, planoconvex, coiled in a very low trochospire ;
dorsal side flat, slightly compressed, ventral side inflated, protruding ; equatorial
periphery roughly ovoid, distinctly lobate ; axial periphery subrounded to subangular
in the early part, angularin the laterpart ; chambers on the dorsal sideabout 9, arrang-
ed in 2 dextrally coiled whorls ; the initial chambers are small, almost masked by the
surface rugosity and are followed by large, crescentic, overlapping chambers which
increase moderately in size ; the last whorl is composed of 4, large, roughly ovoid
chambers, which are elongated in the direction of coiling, and increase slowly and
regularly in size, except for the last which is slightly smaller than the penultimate ;
on the ventral side the chambers are 4, large, subglobular and strongly inflated ;
sutures on the dorsal side curved, depressed ; on the ventral side they are straight,
radial and strongly incised ; umbilicus small, deep and open (although in the figured
specimen the last chamber is strongly pushed over the umbilicus) ; aperture interio-

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 251

marginal, extraumbilical-umbilical ; wall calcareous, perforate ; surface distinctly
papillose or even nodose with the nodes tapering out sometimes to form stout, spine-
like projections, especially along the periphery.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter == O-4% mim:
Minimum diameter = 0-28 mm.
Thickness = 0:20 mm.

REMARKS. Globorotalia wilcoxensis is distinguished by its medium-sized, plano-
convex, roughly ovoid, distinctly lobate test ; its axial periphery which is subrounded
in the early part, angular in the last chamber ; its curved depressed spiral suture ;
its curved, depressed, dorsal intercameral sutures, which are radial and strongly
incised on the ventral side, and its heavily nodose or even spinose surface.

The species is believed to have evolved from G. whiter Weiss in uppermost Paleo-
cene time by the slight increase in the size of test, the close coiling of the early
chambers which become crescentic rather than globular, and by the development of
the more acute axial periphery of last chamber. On the other hand, it has possibly
evolved into G. quetra Bolli by the increase in the size of test, compression of the
dorsal side, and the development of the acute axial periphery and the partially
developed spinose keel.

Subbotina (1953) included G. wilcoxensis in the synonymy of G. crassata (Cushman)
in spite of their marked difference. However, her G. crassata actually belongs to
G. aequa Cushman & Renz which is also quite distinct from the present species.

Said & Kenawy (1956) described as Tvuncorotalia wilcoxensis (Cushman & Ponton)
from the Paleocene of Nekhl section, northern Sinai, Egypt, a form which has nothing
in common with G. wilcoxensis but most probably belongs to G. avagonensis Nuttall,
thus proving their Paleocene to be of Lower Eocene age.

Bolli (19570) described as G. wilcoxensis Cushman & Ponton, a form which appears
to be more closely related to G. whiter Weiss, while the form described by Hamilton
& Rex (1959) cannot be assigned to any known species.

Berggren (1960a) described as G. wilcoxensis from the Lower Eocene of Denmark,
forms which may be related to G. esnaensis (LeRoy).

HypotyPe. P.45643.

HORIZON AND LOCALITY. Figured specimen, from sample No. 64, Gebel Owaina
section.

STRATIGRAPHICAL RANGE. Cushman & Ponton (1932) described G. wilcoxensis
from the Lower Eocene Wilcox group of Alabama, and it was recorded from the same
group by Cushman & Garrett (1939) and Cushman (1944). It was also recorded
from the Lower Eocene Wilcox group of Virginia and Maryland (Cushman 1944)
and Shifflett 1948) ; the Middle Eocene of the Mississippi (Cushman & Todd 1948) ;
the Paleocene Madruga formation of Cuba (Cushman & Bermudez 1949) and the
Lower and Upper Eocene of the same area (Bermudez 1950) ; from the Eocene of the
Gulf of Mexico, the Carribbean region and the Middle East (Grimsdale 1951) ; from

252 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

the Eocene of the mid-Pacific sea mounts (Hamilton 1953) and the Paleocene
Salina and Pale Greda formations of Peru (Weiss.1955a, 0).

In the Esna—Idfu region, G. wilcoxensis appears at the top of the G. velascoensis
Zone as a rare form which crosses the Paleocene-Lower Eocene boundary, and
increases gradually upwards in the section to flood the basal part of the Eocene,
characterizing the Globorotalia wilcoxensis Zone.

Globorotalia woodi sp. nov.
(Pl. 23, figs. 2a—c)

Diacnosis. <A Globorotalia with small, umbilico-convex test ; chambers which
increase rapidly in size ; narrow umbilicus ; long, narrow aperture ; curved, depressed
dorsal sutures and slightly curved, incised ventral ones ; delicate but distinct
marginal keel ; delicately papillose surface.

DESCRIPTION. Test small, umbilico-convex, coiled in a low trochospire ; dorsal
side almost flat, although the early chambers are slightly raised ; ventral side distinct-
ly protruding ; equatorial periphery ovoid, elongate, slightly lobate with a delicately
beaded marginal keel ; axial periphery angular, acute ; chambers on the dorsal side
are not all clear because of the surface rugosity, but appear to be II in number,
arranged in 2 sinistrally coiled whorls ; the last whorl is composed of 5 relatively
large crescentic chambers, which increase rapidly in size ; on the ventral side, the
chambers are 5, roughly triangular, angular conical, increasing rapidly in size ;
sutures on the dorsal side curved, delicately beaded, and slightly depressed ; on the
ventral side they are slightly curved and strongly depressed ; umbilicus extremely
small, moderately deep and open ; aperture interiomarginal, extraumbilical-umbilical,
a long, narrow arch, with a narrow delicate lip ; wall calcareous perforate ; surface
rough papillose, with the roughness decreasing gradually towards the last chamber.

DIMENSIONS OF HOLOTYPE.

Maximum diameter ==) O-27-nam.
Minimum diameter == 0°21 Thm.
Thickness = 10°05 Min.

REMARKS. Globorotalia woodi sp. nov. is morphologically similar to both Globo-
votalia planoconica Subbotina and Globorotalia pseudoscitula var. elongata Glaessner.
It differs from the former in having a slightly larger test, more protruding ventral
side, slightly curved ventral sutures, well-developed marginal keel, and rough surface.
It is distinguished from G. pseudoscitula var. elongata Glaessner by its well developed
marginal keel, sharply angular axial periphery and rough surface.

Globorotalia woodi is believed to have evolved from G. emilet sp. nov. either
directly or indirectly through its descendant G. psewdomenardii Bolli by flattening of
the dorsal side and greater protrusion of the ventral, and by the development of a
more tightly coiled test, rough surface and a delicately beaded keel.

This species is named after Professor Alan Wood, U.C.W., Aberystwyth.

HoLotyPe. P.45616.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 253

PARATYPE. P.45671.

HorRIzON AND Locality. Holo- and paratypes, from sample No. 40, Gebel
Owaina section.

STRATIGRAPHICAL RANGE. The species occurs as a rare to common form through-
out the Upper Paleocene G. velascoensis Zone, of the Esna—Idfu region.

Globorotalia sp.
(Pl. 23, figs. 8a—d)

DESCRIPTION. Test medium-sized, strongly umbilico-convex, coiled in a very low
trochospire ; dorsal side slightly depressed, ventral side strongly protruding, equa-
torial periphery roughly quadrate, distinctly lobate, with a faint, delicately beaded
marginal keel which is sometimes masked by the surface rugosity ; axial periphery,
sharply angular, acute ; chambers on the dorsal side about g, arranged in 2 sinistrally
coiled whorls ; the initial chambers are small, indistinct and almost masked by the
surface rugosity ; the last whorl is composed of 44 chambers (33 + 1 broken) which
are large, roughly oblong-shaped, elongate and increasing slowly in size ; on the
ventral side the chambers are 44 (34 + 1 broken), large, inflated, strongly protruding,
and much longer than wide ; sutures on the dorsal side short, curved and depressed ;
on the ventral side they are radial and strongly incised ; umbilicus very small,
narrow and open ; aperture interiomarginal, extraumbilical-umbilical, a long,
crescentic arch, extending almost to the periphery ; wall calcareous, perforate ;
surface heavily papillose or even nodose, with the nodes sometimes tapering out to
form stout spine-like projections.

DIMENSIONS OF DESCRIBED SPECIMEN.

Maximum diameter == O-3o mm.
Minimum diameter == 0634 min,
Thickness — O27 SUED.

ReMARKS. Although this form could not be assigned to any known species of
Globorotalia, it was decided not to describe it as new pending further study.

It is distinguished by its medium-sized test ; quadrate appearance ; sharply
angular axial periphery ; flat or slightly concave dorsal side and protruding ventral
one ; oblong shaped chambers on the dorsal side, and triangular, elongated chambers
on the ventral; curved, depressed dorsal sutures and radial incised ventral ones ;
narrow umbilicus, weakly developed marginal keel, and rough surface.

The forms described by Loeblich & Tappan (1957a, pl. 46, figs. 7a-8c ; pl. 59,
figs. 6a—c) as G. aequa Cushman & Renz are very similar.

MATERIAL. P.45644.

HORIZON AND LOCALITY. Figured specimen, from sample No. 35, Gebel Owaina
section.

STRATIGRAPHICAL RANGE. This form is rare in the upper part of the Middle
Paleocene G. angulata Zone. It crosses the Middle-Upper Paleocene boundary and
continues in the lower part of the G. velascoensis Zone, the G. pseudomenardii Sub-
zone where it dies out gradually towards the top.

254 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

VI. SUMMARY AND CONCLUSIONS

A detailed examination of the various outcrops in the Esna—Idfu region has led to
the classification of its Upper Cretaceous-Lower Tertiary succession into five
formations and eight members, three formations and seven members of which are
here described for the first time. These are as follows :

TOP E. The Thebes Limestone and Calcareous Shale Formation. The: ane

8. The Thebes Limestone Member. Cie y

7. The Thebes Calcareous Shale Member. P
D. The Owaina Shale Formation.

6. The Upper Owaina Shale Member.

5. The Middle Owaina Chalk Member.

4. The Lower Owaina Shale Member.
renews DISCONFORMITY sannww
C. The Sharawna Shale Formation.

3. The Upper Sharawna Shale Member.

2. The Middle Sharawna Marl Member.

1. The Lower Sharawna Shale Member.

B. The Sibaiya Phosphate Formation. The Nubia
A. The Nubia Sandstone and Variegated Shale Formation. Group

These rock units were used as a basis for the detailed mapping of the region.
This mapping has proved the existence of a distinct stratigraphical break between
the Maestrichtian and the overlying Paleocene. In spite of repeated emphasis
on the absolute conformity of the succession by previous authors, a conglomerate
with reworked Upper Cretaceous fossils was clearly observed in the field and was
found to mark a distinct faunal break in the succession. The detailed lithostrati-
graphy and the maps are presented elsewhere (El-Naggar, im manu), but small
scale reproductions of these maps are, however, given here to show the distribution
of the various rock units and the locations of the sections examined.

The succession was first zoned on the basis of its macrofossils. One hundred and
forty two species were identified. Consideration of their ranges led to the recognition
of five faunal zones and three subzones, in addition to a zone devoid of macrofossils
near the top and a non-fossiliferous zone at the base of the succession. These are as
follows :

TOP 7. The Lucina thebaica Zone.

6. A Zone devoid of macrofossils.
5. The Ostrea hypoptera Zone.
4. The Caryosmilia granosa Zone.
ann DISCONFORMITY nnn
3. The Pecten (Chlamys) mayereymari Zone.
(c) The Libycoceras berisensis Subzone.
(b) The Pecten (Chlamys) mayereyman Subzone.
(a) The Terebratulina gracilis Subzone.
2. The Lopha villei Zone.
1. A non-fossiliferous Zone.

The Esna
Group

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 255

This faunal sequence has been correlated with previously described successions
elsewhere in Egypt.

The planktonic Foraminfera from eight main sections representing the succession
in different parts of the region were then studied. One hundred and nineteen species
and subspecies were identified, twenty species and six subspecies of which are new.
These provided a sound basis for the zonation of the succession and for its correlation
with the known planktonic foraminiferal zones in other parts of the world. This
zonal scheme has helped to establish the true ranges of the co-existent macrofossils,
most of which are not known from outside the Middle East and North Africa. Again,
the rich planktonic foraminiferal populations encountered have helped to clear up the
confusion surrounding most of the species and to establish their morphological
characters and stratigraphical ranges. They have also helped to explain the inter-
and intra- specific variations among large species populations and have indicated
certain trends and tendencies in their phylogenetic development. Seven faunal
zones and four subzones have been erected on the basis of the planktonic Fora-
minifera ; in addition, three other zones, which are either devoid of planktonic
Foraminifera or which contain rare indeterminable forms have been recognized.
These zones and subzones are as follows :

1o. A Zone with indeterminable planktonic Foraminifera.
g. The Globorotalia wilcoxensis Zone.
8. The Globorotalia velascoensis Zone.
(6) The Globorotalia aequa/Globorotalia esnaensis Subzone.
(a) The Globorotalia pseudomenardit Subzone.
7. The Globorotalia angulata Zone.
(0) The Globorotalia pusilla Subzone.
(a) The Globorotalia uncinata Subzone.

6. The Globorotalia compressa/Globigerina daubjergensis Zone.
an DISCONFORMITY wanrnnnwawwww
The Globotruncana esnehensis Zone.

The Globotruncana ganssert Zone.

The Globotruncana fornicata Zone.

A Zone with rare indeterminable planktonic Foraminifera.
1. A Non-fossiliferous Zone.

Nw Bo

A consideration of the lithological classification of the succession together with the
macro-fossil and planktonic foraminiferal zonation enabled a correlation to be made
with comparable successions in Egypt and other parts of the world, and led to the
following conclusions :

A. CONCLUSIONS CONCERNING THE STRATIGRAPHY OF THE EsNnA-IDFU REGION.
1. The Nubia Sandstone and Variegated Shale, which is the oldest formation to
crop out in the region is of Campanian and ?pre-Campanian age.
2. The Sibaiya Phosphate formation is of Upper Campanian age. It is charac-
terized by the Lopha villei Zone and is equated with the Bostrychoceras polyplocum
Zone which characterizes the Upper Campanian in its type section.

256 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

3. The Sharawna Shale formation is of Maestrichtian age. It conformably
overlies the Sibaiya Phosphate formation, and is separated from the overlying
Paleocene Owaina shale formation by a distinct break. It is characterized by one
major macro-fossil zone, the Pecten (Chlamys) mayereymart Zone, which contains
three subzones as mentioned above. It is divided on the basis of its lithology into
three distinct members : the Lower Sharawna Shale member, the Middle Sharawna
Marl member and the Upper Sharawna Shale member. These correspond to the
Terebratulina gracilis Subzone, the Pecten (Chlamys) mayereymari Subzone and the
Libycoceras berisensis Subzone in the macrofossil zonation respectively. They also
correspond to the Globotruncana fornicata Zone, the lower part of the Globotruncana
gansseri Zone and both the upper part of the latter zone and the Globotruncana
esnehensis Zone in the planktonic foraminiferal zonation. These three planktonic
foraminiferal zones are taken to represent the Lower, Middle and Upper Maestrich-
tian and are correlated with corresponding zones in other parts of the world.

4. The Mesozoic—Cainozoic boundary in the Esna—Idfu region is marked by a
distinct break and by a well developed conglomerate as mentioned above. It has
been shown that this break is widespread throughout the country and exists in
regions where conformity has hitherto been assumed.

5. The disconformity which marks the top of the Maestrichtian Sharawna Shale
formation indicates the passage of a relatively long period of time, and represents
the uppermost Maestrichtian as well as the Lower and Middle Danian.

6. The Owaina Shale Formation is of Paleocene age. It disconformably overlies
the Maestrichtian Sharawna Shale and includes three members : The Lower Owaina
Shale member, the Middle Owaina Chalk member and the Upper Owaina Shale
member. Its Lower and Middle members coincide with both the Caryosmuilia granosa
and the Ostrea hypoptera Zones respectively, while its upper member is devoid of
macrofossils except for rare dwarfed forms seen only in washed residues. On the
basis of its planktonic Foraminifera, the Owaina Shale formation is divided into the
three zones and four subzones listed above. The Globorotalia compressa/Globigerina
daubjergensis Zone which coincides with the basal part of the Lower Sharawna
Shale member, is also known to characterize the Danian in its type section and in
other parts of the world. However the abundance of G. compressa clearly indicates
that this part of the succession corresponds to the Upper Danian only, and proves that
both the Lower and Middle Danian are missing. The G. compressa/G. daubjergensis
Zone represents the Lower Paleocene (or Danian), while the G. angulata and the
G. velascoensis Zones represent the Middle and Upper Paleocene respectively.

7. The various stage and substage names of the Paleocene such as the Montian,
Thanetian, Sparnacian, Landenian, Heersian, Seelandian, etc., could not be applied
because the relationship between one stage and another is not clearly understood,
and the proper position of each in Paleocene stratigraphy is not known.

8. The Maestrichtian Sharawna Shale and the Paleocene Owaina Shale forma-
tions, together constitute a major group, commonly known as the Esna Shale.
Previous classifications of this group into lower and upper Esna Shale, or into
Dakhla and Esna shales are incorrect.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 257

g. The Paleocene—Eocene boundary is marked by the upper limit of the Globo-
votalia velascoensis Zone.
ro. The Thebes Limestone and Calcareous Shale formation is of Lower Eocene
age. It is naturally classified into : a lower, “‘ Thebes Calcareous Shale member ”’,
and an upper, ‘“‘ Thebes Limestone member ’’, which forms the top part of the
succession in the region. The former member is devoid of macrofossils except for
rare dwarfed forms seen only in washed residues. It is characterized by the Globo-
votalia wilcoxensis Zone which is taken to mark the basal Eocene in Egypt and in
other parts of the world. The latter member corresponds to the Lucina thebaica
Zone of the macrofossil zonation. It is flooded with larger Foraminifera such as
Nummutltes, Operculina, Assilina, Discocyclina, etc., but, because of its silicification,
it has not yet yielded any determinable planktonic forms. Nevertheless, its lower
part, most probably, still belongs to the G. wilcoxensis Zone.

B. GENERAL CONCLUSIONS.

1. The Maestrichtian is considered to be a distinct stage in Upper Cretaceous
stratigraphy, younger than, and equal in rank to the Senonian stage, while the
Campanian is considered to be the upper substage of the Senonian as previously
suggested by Jeletzky 1951.

2. The Campanian—Maestrichtian boundary is drawn at the top of the Bostry-
choceras polyplocum Zone = the Lopha villei Zone = the Globotruncana calcarata
Zone which marks the top of the Campanian in different parts of the world.

3. The Maestrichtian is divided on the basis of its planktonic Foraminifera into
three successive zones ; the Globotruncana fornicata Zone, the Globotruncana ganssert
Zone and the Globotruncana esnehensis Zone. The lowest zone is younger than the
Upper Senonian in its type sections, while the upper zone is correlated in part with
the Abathomphalus mayaroensis Zone which marks the Upper Maestrichtian rocks
below the type Danian. A study of the type Maestrichtian should reveal the
existence of these zones in Holland.

4. The Danian is considered to be the oldest stage of the Tertiary system, and the
Maestrichtian—Danian contact is taken to mark the Mesozoic—Cainozoic boundary.

5. Comparison with previously studied Upper Cretaceous—Lower Tertiary succes-
sions, showed that in Egypt, this succession which was previously held to bea
classical example of continuous deposition between the Cretaceous and the Tertiary
is marked by breaks of varying magnitude. Comparison with similar successions in
other parts of the world showed that the Mesozoic is separated from the Cainozoic
in all known sections by a world-wide break, the cause of which awaits explanation.

6. The Paleocene is considered to be a distinct series at the base of the Tertiary
system. older than, and equal in rank to the Eocene series. It spans the time
between the top of the Cretaceous and the base of the Eocene, and includes the
Danian as its lowest stage. The controversy over the chronological and strat-
graphical relationships of the various other stages and substages of the Paleocene
(e.g. the Montian, Thanetian, Sparnacian, Landenian, Heersian, Seelandian, etc.),
necessitates the temporary abandonment of these terms, and the use of planktonic

258 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

foraminiferal zones instead. The Paleocene is divided on the basis of its planktonic
Foraminifera into the following three zones ; the Globorotalia compressa/Globigerina
daubjergensis Zone, the Globorotalia angulata Zone and the Globorotalia velascoensis
Zone. These are taken to represent the Lower Paleocene (or the Danian), the Middle
Paleocene, and the Upper Paleocene respectively. The assignment of either of the
last two zones to the Montian, Thanetian, Sparnacian, Landenian or Ilerdian, as
suggested by various authors, is rather arbitrary, and is not based on proper correla-
tion with the type sections.

7. The term “ Ilerdian ’’ should be dropped from Paleocene stratigraphy as it is
very misleading.

8. The Paleocene—Eocene boundary is marked by the complete disappearance of
Globorotalia velascoensis velascoensis (Cushman) and its associated fauna, by the
first appearance of Globorotalia bollii sp.nov., and by the flood of Globorotalia wilcox-
ensts Cushman & Ponton.

g. The basal Eocene is marked by the Globorotalia wilcoxensis Zone. The
relationship between the Ypresian and the Cuisian is not yet completely understood ;
the term Ypresian appears to be more appropriate inasmuch as the type Ypresian
alsc includes the Cuisian, but the fact that the planktonic Foraminifera in these
type stages are not correctly known, neccesitates the temporary abandonment of
these terms.

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IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 259

APPENDIX

While this work was in press, Said & Sabry published their work on “ Planktonic
Foraminifera from the type locality of the Esna Shale in Egypt ” (Micropaleontology,
10 : 375-395, pls. 1-3), and the following comments are made on the results of their
study:

A. CONCERNING THEIR BIOSTRATIGRAPHICAL ZONATION.

(I). Owing to their limited study, Said & Sabry have ignored the varied plank-
tonic foraminiferal fauna of the Maestrichtian and in addition to the fact that
practically all their Globotruncana species are wrongly identified they have
overlooked the following forms which characterize the Maestrichtian part of the
succession :

Globotruncana adamsi sp. nov. G. leupoldi Bolli

G. arabica sp. nov. G. lugeom Tilev

G. bahiae sp. nov. G. mariai Gandolfi

G. comca White G. mariei Banner & Blow

G. contusa contusa (Cushman) G. orientalis sp. nov.

G. contusa patelliformis Gandolfi G. rosetta pettersi Gandolfi

G. contusa scutilla Gandolft G. shavawnaensis sp. nov.

G. contusa witwickae subsp. nov. G. stuarti parva Gandolfi

G. cf. convexa Sandidge G. stuart stuartiformis Dalbiez

G, esnehensis Nakkady & Osman G. stuarti subspinosa Pessagno

G. faveedi sp. nov. G. subcivcumnodifey Gandolfi

G. fornicata ackermanni Gandolfi G. tricarinata colombiana Gandolft
G. fornicata cesavensis Gandolfi G. tricarinata tricarinata (Quereau)
G. fornicata fornicata Plummer G. ventricosa White

G. fornicata globulocamerata subsp. nov. G. youssefi sp. nov.

G. fornicata manaurvensis Gandolfi Rugoglobigerina glaessnert Gandolfi
G. fundiconulosa Subbotina R. loetterli (Nauss)

G. gagnebini Tilev R. macrocephala Bronnimann

G. cf. gagnebini Tilev R. pennyi Bronnimann

G. gansseri dicavinata Pessagno R. votundata Bronnimann

G. ganssert gandolfii subsp. nov. A. mayaroensis (Bolli)

G. gansseri ganssert Bolli

G. gansservi subganssert Gandolfi Trimitella scotti Bronnimann

G. havanensis Voorwijk Abathomphalus intermedia (Bolli)

(2). In their treatment of the Paleocene-Lower Eocene succession they have
almost literally followed Bolli’s (19575) zonation, but their failure to recognize both
Globorotalia trinidadensis Bolli and G. compressa (Plummer) which flood the basal
part of the Paleocene has led them to discuss “ a Globigerina daubjergensis—Globoro-
talia pseudobulloides zone’’. Globorotalia pseudobulloides, however, ranges through-
out the Paleocene and cannot, therefore, be used for its subdivision. Their figured
Globigerina daubjergensis Bronnimann (pl. 3, figs. 8a—c) does not belong to this
species.

Their references (p. 384, pl. I, figs. 16a—c and p. 388, no figs.) to a Lower Landen-
ian Globorotalia pseudobulloides (Plummer) and a Danian Globigerina pseudobulloides
Plummer is rather confusing as both include Plummer’s holotype (1926 : 133, pl.
8, figs. ga—c) in the relevant synonymies.

260 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

(3). Following Bolli (19570) they mention a “ Globorotalia uncinata zone’.
However, G. uncinata, as seen in the present study, occurs in the upper part of the
“ Globorotalia compressa/Globigerina daubjergensis Zone ’’ and continues almost to the
base of the “ G. velascoensis Zone’’. It floods the lower part of the “ G. angulata
Zone”’ and is only taken to characterize this part as a distinct subzone. They also
refer to the occurrence in this zone of Globorotalia compressa (Plummer) and Globoro-
talia colligera (Schwager) among others, although G. compressa is restricted to the
Danian and G. colligera was originally described from the Lower Eocene.

(4). Again, following Bolli (19570) they refer to a “ Globorotalia pusilla pusilla
Zone’, stating that this subspecies marks a zone at the base of the Landenian to
which it is restricted, while the other subspecies G. pusilla laevigata only exists in the
basal Eocene. However, in the present study G. pusilla pusilla was found to flood
the upper part of the “ G. angulata Zone ’’, characterizing a particular subzone, and
to fade out gradually into the basal part of the overlying “ G. velascoensis zone.’’,
while G. pusilla laevigata ranges throughout the lower part of the latter zone, but not
in the Lower Eocene. They state (p. 380) that “ The topmost 10 metres of the
Dakhla shale of Gebel Aweina are characterized by a number of Globorotalia species
that belong to the sharply keeled forms: G. pusilla pusilla, G. angulata, G. perclara, G.

ehrenbergi, G. triplex and G. simulatilis ...”’, none of which is a sharply keeled form.
(5). Like Bolli (19570) they mention a “ Globorotalia pseudomenardu zone’”’ anda
“ Globorotalia velascoensis zone’’. The present study, however, showed that the

two species appear for the first time together and the former only characterizes the
lower part of a zone distinguished by the latter species. They also mention the
existence in the “ G. velascoensis zone”’ of Globorotalia broedermanm Cushman &
Bermudez, a known Lower—Middle Eocene form. Moreover, they extend the range
of G. velascoensis to cover 76 ms. above the chalk, while the species has been found in
the present study to die out completely at a vertical distance of 60 ms. from the top
of the chalk.

(6). Because of their uncertainty, they state (p. 380) : “‘ The age of the above
mentioned four zones is interpreted as Landenian, although the G. pusilla and G.
pseudomenardu zones could well be Montian, in which case the G. wncinata zone
might be either Danian or Montian ”’.

J

(7). They refer to a “ Globorotalia rex zone”’ of Ypresian age, although their
figured G. vex Martin (p. 385, pl. 2, figs. 3a—c) 1s possibly G. bollit El-Naggar. They
also record the occurrence of G. pusilla laevigata Bolli and G. conicotruncata Subbotina
in their ““G. vex zone’”’. The former species is restricted to the lower part of the
Upper Paleocene, while the latter is probably synonymous with the definitely
Paleocene G. angulata abundocamerata Bolli.

B. CONCERNING THEIR DETERMINATIONS OF PLANKTONIC FORAMINIFERA :
(1). Praeglobotruncana coarctata Bolli (p. 381, pl. 3, fig. 23) is Rugoglobigerina

macrocephala Brénnimann ; Bolli’s species is morphologically and stratigraphically
distinct and has only been recorded from the Lower Campanian.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 2601

(2). Globorotalia aequa Cushman & Renz (pp. 381, 382, pl. 2, fig. 8) isa keeled form
while the holotype and hypotypes in the present study are not at all keeled. They
appear to have lumped several other forms within their G. aequa such as G. loeblicht
El-Naggar. This is clear from their description (p. 382) “..... peripheral margin
sharply angled, sometimes with a well developed keel; ..... umbilicus wide ;
eae keel and spiral sutures thickened and nodose ; ventral side smooth ”’.

(3). Globorotalia angulata (White) (p. 382, pl. I, fig. 3) is probably a transitional
stage to G. angulata abundocamerata Boll ; it is a keeled form with five chambers in
the last whorl while White’s holotype is typically non-keeled. Their Globorotalia
contcotruncata (Subbotina) (p. 383, pl. 2, fig. 7) is probably G. angulata angulata
(White).

(4). Globorotalia broedermanm Cushman & Bermudez (p. 382, pl. 1, fig. 4) differs
from the holotype in being much larger, flatter on the dorsal side and less tightly
coiled.

(5). Globorotalia colligera (Schwager) (p. 382, pl. 1, fig. 14) does not belong to this
species ; Schwager’s form was recorded from younger strata and the holotype needs
to be redrawn and redescribed in more detail.

(6). Globorotalia compressa (Plummer) (p. 382, pl. 3, fig. 13) probably belongs to
Globorotalia emilet El-Naggar. Globorotalia compressa is restricted to the Danian,
while their form comes from the Lower Landenian.

(7). Globorotalia convexa Subbotina (p. 383, pl. 3, fig. 17) differs from the holotype
in having fewer chambers and in lacking a concave, bulla-like last chamber. It
probably belongs to the form described in the present study as Globorotalia cf.
convexa.

(8). Globorotalia imitata Subbotina (p. 383, pl. 3, fig. 6) differs from the holo- and
paratypes of Subbotina and the hypotypes of the present study in being much
flatter on the dorsal side, more protruding on the ventral, having more acute axial
periphery and less inflated chambers. The forms recorded in the present study agree
well with Subbotina’s original description and figures.

(9). Globorotalia interposita (Subbotina) (p. 383, pl. I, fig. 15) does not belong to
this species. Acarinina interposita Subbotina is a synonym of Globigerina soldado-
ensis Bronnimann.

(10). Globorotalia lensiformis Subbotina (p. 383, pl. 2, fig. 2) is Globorotalia
occlusa Loeblich & Tappan. Subbotina’s form was described from the Lower—
Middle Eocene while their form is recorded from the Upper Landenian.

(11). Globorotalia pentacamerata (Subbotina) (p. 384, pl. 1, fig. 6) is probably a
deformed specimen of Globigerina mckannai White.

(12). Globorotalia planoconica Subbotina (p. 384, pl. 3, fig. 12) apparently
includes forms related to both Globorotalia emilei El-Naggar and G. troelsent Loeblich
& Tappan. Subbotina’s form was originally described from the Lower—Middle
Eocene while theirs comes from the Upper Landenian—Ypresian.

(13). Globorotalia pseudobulloides (Plummer) (p. 384, pl. I, fig. 16) seems doubtful
because of their description of the chambers as compressed and of the surface as

262 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

smooth. Their form is stated to occur in the “ G. wncinata zone ’’ while G. pseudo-
bulloides ranges throughout the Paleocene.

(14). Globorotalia pseudoscitula Glaessner (p. 384, pl. 2, fig. 1) is quite distinct
from Glaessner’s form. Judging from their figure and very brief description, it may
well belong to Globorotalia pusilla laevigata Bolli although it appears to be much
larger.

(15). Globorotalia pseudotopilensis (Subbotina) (pp. 384, 385, pl. 1, fig. 9) is very
different from Subbotina’s form which in any case is a junior synonym of Globorotalia
esnaensis (Le Roy). It probably belongs to Globorotalia tribulosa Loeblich & Tappan.

(16). Globorotalia pusilla laevigata Bolli (p. 385, pl. 3, fig. 7) belongs to Globorotalia
woodi El-Naggar.

(17). Globorotalia quadrata Nakkady & Talaat (p. 385, pl. 1, fig. 10) belongs to
Globorotalia quadrata (White).

(18). Globorotalia rex Martin (p. 385, pl. 2, fig. 3) belongs to Globorotalia bollit
El-Naggar.

(19). Globorotalia simulatilis (Schwager) (p. 385, pl. 1, fig. 1) probably belongs to
Globorotalia angulata abundocamerata Bolli. G. simulatilis was originally described
from younger strata and its holotype needs to be redrawn and redescribed in more
detail.

(20). Globorotalia triplex (Subbotina) (p. 385, pl. 1, fig. 8) differs from Subbotina’s
holotype of Acarinina triplex which is probably Globigerina velascoensis Cushman.

(21) Globorotalia varianta (Subbotina) (p. 386, pl. 3, fig. 9) probably belongs to
Globorotalia cf. convexa of the present study. Globigerina varianta Subbotina is a
different form which probably includes Globorotalia pseudobulloides (Plummer),
Globorotalia quadrata (White) and Globorotalia esnaensis (Le Roy).

(22). Globorotalia velascoensis (Cushman) (p. 386, pl. 2, fig. 9) is probably a
transitional form between Globorotalia angulata abundocamerata Bolli and Globoro-
talia velascoensis velascoensis (Cushman).

(23). Globorotalia wilcoxensis Cushman & Ponton (p. 386, pl. 3, fig. 14) probably
belongs to Globorotalia white: Weiss.

(24). Rugoglobigerina bulbosa Belford (p. 386, pl. 3, fig. 15) probably belongs to
Rugoglobigerina rugosa (Plummer).

(25). Rugoglobigerina reicheli pustulata Bronnimann (p. 386, pl. 3, fig. 16) is a
doubtful form. It is described as having a smooth surface while the holotype is
extremely rough and coarsely rugose.

(26). Globotruncana aegyptiaca Nakkady (pp. 386, 387, pl. 3, fig. 1) does not
belong to this species. It is described as single-keeled while the holo- and paratypes
of Nakkady, as well as the hypotypes of the present study, are entirely double-
keeled. Probably the form is double-keeled and, if so, it should be attributed to
Globotruncana gagnebini Tilev as can be seen from their figures.

(27). Globotruncana aegyptiaca var. duwi Nakkady (p. 387, pl. 3, fig. 2) is shown
to have a single keel although the holo- and paratypes of Nakkady, as well as hypo-
types in the present study, are entirely double-keeled.

(28). Globotruncana arca (Cushman) (p. 387, pl. 2, fig. 5) belongs to Globotruncana
gagnebimi Tilev.

IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 263

(29). Globotruncana cretacea Cushman (p. 387, pl. 3, fig. 4) is probably a deformed
specimen of Globotruncana stuarti stuarti (de Lapparent). It is described as being
biconvex and single-keeled while Cushman’s form, as re-examined by Brénnimann &
Brown (1956), has two keels in all chambers of the last whorl.

(30). Globotruncana ganssert Bolli (p. 387, pl. 3, fig. 3) is a doubtful form. It is
described as having a distinct and keeled umbilical shoulder and an aperture with
perforate tegilla. It is not really known what is meant by keeled umbilical shoulder
or perforate tegilla as the latter are always imperforate. Again, while they described
the chamber number as 5-6 in the last whorl, their figured specimen shows only 3}
chambers.

(31). Globotruncana rosetta (Carsey) (p. 387, pl. 3, fig. 5) 1s shown to have an
entirely single keel while the holotype is characterized by two closely spaced keels
on the early part of the last whorl (see Bronnimann & Brown 1956).

(32). Globotruncana stuart (de Lapparent) (p. 387, pl. 2, fig. 3) belongs to Globo-
truncana conica White.

(33). Globigerina daubjergensis Bronnimann (p. 387, pl. 3, fig. 8) does not belong
to this species. It is much larger, less raised on the dorsal side and has fewer
charnbers in the last whorl which increase more rapidly than in the typical form. It
is probably Globigerina triloculinoides Plummer.

(34). Globigerina inaequispiva Subbotina (p. 387, pl. 3, fig. 10) is a doubtful form
which differs markedly from the holotype.

(35). Globigerina pseudobulloides Plummer (p. 388, no figs.) is a very confusing
record as the authors also recorded what they describe as Globorotalia pseudobulloides
(Plummer) in the same study.

(36). Globigerina quadrata White (p. 388, pl. 3, fig. 22) is clearly shown in their
figure to have an extraumbilical aperture although included by them in the genus
Globigerina.

C. CONCERNING THEIR LITHOSTRATIGRAPHICAL ZONATION.

Following Ghorab (1956) and Said (1961, 1962) they have used the term Dakhla
shale as a substitute for the older term Lower Esna shale. The Dakhla shale, as
originally designated, includes the Maestrichtian Sharawna shale, the conglomerate
separating it from the overlying Paleocene Owaina shale, and the lower part of the
latter formation. These varied, lithological and palaeontological units, which are
clearly separated by a marked break, cannot be treated as one formation. Thus,
the term Dakhla shale is here dropped and the classification of the Esna group into a
Lower Sharawna formation and an Upper Owaina formation is here suggested.

They have treated the chalk separately and restricted the Esna shale to the succes-
sion of strata between the chalk and the base of the Thebes formation which is here
assigned to the Upper Owaina shale member. However, this restricted use of the
term is contrary to the original usage and conflicts with the lithological relationships
of the various units in the field as well as with their palaeontological continuity.

264 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

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1957a. Foraminifera from the Cretaceous of Southern Limburg, Netherlands, 25, some
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1957c. Foraminiferen der Oberkreide von NordwestDeutschland und Holland. Geol. Jb.,
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1958b. Foraminifera from the Cretaceous of Southern Limburg, Netherlands, 33, on
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1959a. Foraminifera from the Cretaceous of Southern Limburg, Netherlands, 39, argu-
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272 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA

Horker, J. 1959d. Foraminifera from the Cretaceous of South Limburg, Netherlands, 41. The
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—— 1959e. Foraminifera from the Cretaceous of South Limburg, Netherlands, 42. On the
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—— 1959h. Les Foraminiferes des craies tuffoides de Charente et Dordogne de |’ Aquitaine,

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IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 273

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280

INDEX
New taxonomic names and the page numbers of the principal references are printed in bold
type. An asterisk (*) indicates a figure.

Abathomphalus, 14, 20, 48, 57, 60-63, 66, 67,
70, 72, 188
intermedia, 48, 61, 62, 66, 67, 70, 99
mayaroensis, 48, 57, 62, 67, 70
Zone, 62, 113, 257
Abou Saboun section, 76, 85, 96, 103, 105,
107, 1090, 213, 1245 142, 045
Abu Durba section, 79, 99
Acarinina, 185, 187
acarinata, 185
clava, 217
conicotruncata, 194, 196, 197
intermedia, 217
interposita, 174
pentacamerata, 170
pseudotopilensis, 211, 218, 220
tviplex, 177, 183, 184, 220
Ain Maqfi section, 58
Albian, 16
Ammonites, 33, 40, 48
Ananchytes ovata, 10, 33
chalk member, 45
Anglo-Franco-Belgian Basin, 24
angulata Zone, 27
Anomalina lorneiana var. trocoidea, 150
Aptian, 16
Aquia formation, 157, 161, 200, 215, 222, 223,
2360
Aquitain Basin, 19
Argile de Vaux-sous-Laon, 23
plastique, 23
Ashen-grey paper shales, 49
Assilina, 32, 66, 257
Aswan, 10
Atlantic Coastal Plain, 93, 165
Atumria cf. praeziczac, 42
Aturian, Io
Atwani, Io

Baculites, 33, 40
anceps, 40
Belemnitella, 16, 17, 85
casimirovensis, 62
lanceolata, 17
mucronata, 16, 17, 85, 124
chalk, 124
Zone, 62
Boliwinoides, 39
Bone beds, 34
Bostrychoceras polyplocum, 17, 18, 40, 43, 46

Zone, 255, 257
s.l. Zone, 46
Bracheux, 23
Brightseat formation, 224
Bucherina, 68, 70
sandidget, 68
Buffer Zone, 35, 36, 39, 55

Cainozoic, 20, 41, 256, 257
Calcaire de Rilly, 23
grossier, 15
de Mons, 25, 26
pisolithique, 16
Campanian, 12, 13, 15-20, 23, 33-35, 37, 40-
43, 45-47, 54, 56, 58, 61, 73, 74, 76, 79, 81,
82, 85, 90, 92, 94-97, 99, 100, 103, 107, 108,
III, 122, 124, 125, 127, 129, 130, 133, 135,
136, 138-144, 146, 255, 257
Campanian/Maestrichtian boundary, 15-17,
257
Cardita beds, 40
dakhlensts, 43
libyca, 40
Caryosmilia granosa, 53
Zone, 53, 63, 64, 254, 256
Catapsydvax, 164, 169
Cenomanian, 16, 130
Cerithium, 15, 19, 25
Cernay conglomerate, 22, 23
Chacra formation, 178
Chalk of d’Obourg, 16
Chalons-Sur-Vesle, 23
Champagne, 18
Chiloguembelina, 21
Chlamys mayereymari, 40
Ciply, 16, 23, 25
Claiborne Cane River formation, 209
Coal Bluff marl member, 217
Colon shale, 92, 94, 95, 103, 116, 120, 127,
133, 141, 146, 147, 152
Coniacian, 16, 41, 46, 74, 95, 107, 108, 110
Cretaceous, 7-10, 12, 13, 15, 18-21, 153, 164,
173, 181, 184, 189, 190, 248, 250, 254, 257
/Tertiary, 7
/ boundary, 20
Cuisian, 23, 24, 29, 52, 258

Dakhla Oasis, 42, 46, 49
ash-grey shale member, 45
shale, 49, 256

INDEX 281

Danian, 10-12, 15-17, 19-28, 30, 32-35, 37—
43, 48-51, 55, 63, 64, 121, 151, 153-155,
158-165, 167, 168, 170, 175, 176, 181, 183,
184, 194, 196, 199, 204-206, 208, 210, 214,
216, 218, 224, 226, 227, 234, 236-238, 241,
242, 256, 257

Danili section, 125

Dano-Montian, 24, 41

Dijon, 18

Discocyclina, 32, 66, 257

Discorbina, 69
simulatilis, 222

Discorbis, 69

Dordonian, 16-18, 33

Durba, 125

Duwi, 41, 45, 125
formation, 41, 45

Eastern Desert, 79, 81, 103
Elburgan horizon, 216
El-Kab, 13
El-Kilabiya, 12
El-Sharawna, 10
E]-Sinn, 8
Eocene, 8, 10-13, 15, 22-25, 28, 29, 31-44,
49-53, 55-58, 66, 156, 157, 161, 168, 170,
W/Z Aly Loy LOO MLO wuOO LOL, LO.
196, 199, 202, 203, 206, 209, 212, 213, 216,
Zig relO-222, 224.234.230.236 ,230, 243),
244, 248-252, 257, 258
Eponides lotus, 41, 42
fauna, 41, 42
Esna, 8-10
formation, 45, 49
group, 49, 254
shale, 8, 10-13, 36, 39, 41, 42, 45, 51, 53,
78, 79, 99. 211, 212, 216, 222, 256
facies, 13
Exogyva overwegt, 10, 33, 40
beds, ro

Farafra Oasis, 36, 56, 58, 85, 100, 196, 210,
2Er, 2Qi2, 216

Faxoé, Calcaire de, 19

Fere, Tuffeau de la, 23

Folx-les Caves, Limestone of, 16

Franco-Belgian Basin, 24

Gamsa Basin, 93
Gebel Duwi, 79, 81, 99
El-Kalabiya section 159, 164, 169, 205, 216
28), 234, 237.
El-Sharawna, 12

Gebel Gurneh section, 42, 58
Owaina, I1*, 12, 38, 42, 45, 79, 81, 89, 115,
120, 123, 145, 148, 150, 156-159, 161,
LOZ, 168, 1725) 174, 1710) 178) ESO) L835
184, 190, 193, 194, 196, 198, 200, 201,
205, 206, 208, 210, 212, 214, 215, 217,
220-222 224, 227, 228, 230, 2319 233)
235, 230, 239, 240, 242, 243, 245, 248,
250, 251, 253
A 314 section, 105, 107, 110
Giddi section, 38, 40, 57
Globanomalina, 58, 238
eocenica, 58, 238
Globigerapsis. 244
Globigevina, 14, 21, 29-31, 38, 39, 43, 54, 55,
57, 58, 60, 63, 65, 60, 73, 152, 153-156, 158,
159, 162, 163, 169, 171, 173, 177, 180, 185,
187, 188, 204, 217, 226, 234
alanwoodi, 63-65, 156, 157, 172, Pl. 16,
figs. 6a—c
angulata, 197, 198
aquiensis, 65, 66, 157, 159, 161, 166, 169,
175
arabica, 63, 157, 158, 159, 175, 214; Pl. 18,
figs. 6a—c
bacuana, 54, 64, 65, 159, 166
belli, 63, 159, 160
bulloides, 54, 57, 73, 153, 154, 180, 225, 234
chascanona, 64, 65, 160, 161, 166, 169, 173,
174; Pl. 16, figs. 4a-c
ciycumnodifer, 141
compacta, 175
compressa, 152, 203, 208
var. compressa, 203, 224, 226
var. pseudobulloides, 224, 226
crassafovmis, 249
cretacea, 37, 38, 54, 125
var. esnehensis, 37, 54, 170, 171
daubjergensis, 25-27, 30, 40, 63, 154, 161—
165, 168-170; Pl. 15, figs. 3a—-c
primitiva, 161
dubia, £70
var. lakiensis, 170
Globigerina edita, 175
eocaenica, 180
var. eocaenica, 180
esnaensis, 55, 50, 210-212
finlayi, 178-180
gvavelli, 170-172, 174
haynesi, 63-65, 159, 165-167, 175, 184;
Pl. 15, figs. 5a—c
hornibrooki, 178-180

282 INDEX

inaequispiva, 58, 63-65, 155, 167, 168, 173;
Pl. 15, figs. 8a—c
cf. Globigerina inaequispiva, 177
kozlowshkti, 63, 64, 157, 163-165, 168-170,
Pl. 15, figs. 1a—2¢
linaperta, 38, 54, 57, 151, 178, 180
loetterli, 147
mckannat, 54, 55, 58, 59, 65, 66, 70, 156,
170-173, 215; Pl. 16, figs. 5a—c
nodosa, 65, 173, 174; Pl. 15. figs. 6a—c
primitiva, 174, 176
pseudobulloides, 57, 56, 224, 225, 227
cf. pseudobulloides, 176, 178, 223, 224
pseudocorpulenta, 157
pseudoeocaena var. trilboba, 177
pseudotriloba, 37, 56, 57, 178, 180
quadvata, 37, 38, 54-56, 233, 234
vosetta, 128
vugosa, 146, 149
soldadoensis, 58, 65, 66,171-173, 174, 212,
217
spiralis, 63-65, 156, 158, 159, 166, 169, 175,
176; Pl. 16. figs. 2a—c
stainforthi, 178-180
stonet, 55, 65, 66, 167, 173, 174, 176-178,
184; Pl. 16. figs. 1ra—d
subcretacea, 56, 57
tvriangularis, 178, 180, 184
triloculinoides, 25, 27, 30, 42, 54-59, 63-65,
153-155, 168, 173, 178-181, 182-184;
Pl. 15, figs. 7a-c
parva, 56, 63-65, 182, 183; Pl. 15, figs.
4a—C
Globigerina triloculinoides var. nanus, 182
trivialis, 178, 180
turgida, 58, 59
varianta, 211, 225, 226
velascoensis, 55, 63-65, 166, 177, 183-185,
220; Pl. 15, figs. 3a-d
var. compressa, 180
SPP. 43
Zone, 39, 55
(Globigerina) 154
(Eoglobigevina) 154, 185, 187
eobulloides, 154, 185
/ Globorotalia Zone, 34, 35
/ rounded Globorotalia assemblage, 199
/ truncated Globorotalia assemblage 199
Globigerinella aspera, 37
Globigerinelloides, 29, 28, 57, 58, 60, 62
Globigerinidae, 153
Globigerininae, 153

Globigerinoides, 21, 162, 163, 164, 169
daubjergensis, 161
Globoconusa, 153, 154, 163
conusa, 153, 154, 161, 163
quadripartitaformis, 154
Globoquadrina primitiva, 177
Globorotalia, 14, 21, 29-31, 35, 36, 38, 39, 50
55-58, 60, 63-66, 69, 72, 120, 150, 152-156,
171, 180, 185-188, 194, 198, 204, 211, 212,
226, 234, 238, 247, 253
acuta, 56, 63-65, 170, 188-190, 200, 244,
245, 248; Pl. 19, figs. 5a—c; Pl. 20, figs.
ta—d
acutispiva, 221, 222
aequa, 55, 64-66, 187, 190-193, 198, 202,
213, 219, 220, 229, 251; Pl. 21, figs. 4a—c
aequa | Globorotalia esnaensis Subzone, 60,
65, 157, 159, 172, 174, 176, 178, 193, 194,
200, 200, 210, 212, 215, 217, 220meom,
223,224, 230, 235, 236, 245, 250, 253,255
Globorotalia africana, 64, 193, 194; Pl. 23,
figs. 4a—c
angulata, 55, 50, 58, 165, 170, 195-197, 200,
222, 230
abundocamerata, 30, 31, 56-59, 63-65,
190, 194-197, 198, 200, 206, 248; PI.
22, figs. 2a—c
angulata, 30, 31, 56, 58, 63-65, 165, 187,
190, 192, 193, 195, 196, 197-199, 200,
205, 218,°232, 234, 240. 242) eller
figs. Ia—c
conicotruncata, 196
group, 50
var. hubanensis, 194, 195
var. praepentacamerata, 196, 197
Zone, 30, 50, 60, 63, 64, 160, 168, 170,
199, 210, 238, 242, 253, 255, 256, 258
apanthesma, 63-65, 187, 194, 196, 197, 199,
200, 215; Pl. 21, figs. ta—c
avagonensis, 57, 192, 222, 243, 247, 251
val. CAUCASICA, 242, 243, 247
Zone, 178
berggreni, 65, 200, 201, 212, 217; Pl. 23,
figs. 7a-c
bollii, 51, 58, 64-66, 202, 203, 248, 258;
Pl. 22, figs. 5a—d, 6a—d
centyalis, 185
colligeva, 54, 58, 59, 192
var. cvassaformis, 54, 55
compressa, 25, 30, 40, 43, 50, 54, 63, 151,
152, 165, 170, 180, 203-205, 207, 209,
210, 216, 218, 224, 220) 227, 250; mln
figs. La—3¢

INDEX

| Globigerina daubjergensis Zone, 30, 50,
60, 62, 63, 160, 183, 255, 256, 258

conicotvuncata, 42, 58, 194, 196

convexa, 58, 59, 195, 196, 213, 220, 233

Globorotalia cf. convexa, 63-65, 205-207, 213,
214; Pl. 22, figs. 3a-c

crassaformis, 249

cvassata, 190-192, 251
var. aequa, 54, 55, 190, I9I

cratey, 246, 247

deceptoria, 54, 55

ehrenbergi, 25, 63, 64, 204, 207, 208,216;
Pl. 17, figs. 5a-c

elongata, 208, 210

emilei, 55, 57, 63-05, 204, 205, 207, 208—
210, 228, 238, 239, 252; Pl. 17, figs. ga-c

esnaensis, 58, 65, 66, 174, 193, 201, 210—
213, 220, 226, 229, 236, 249, 251; Pl. 21,
figs. 6a—c

faragi, 63-65, 206, 213, 214; Pl. ro, figs.
4a—C

formosa formosa, 58
gracilis, 192, 248

hispidicidaris, 65, 172, 187, 200, 214, 215;
Pl. 21, figs. 5a—c

imitata, 42, 58, 59, 63-65, 208, 215, 216,
227; Pl. 17, figs. 6a—c

imconstans, 242

inflata, 209

imtermedia, 235

interposita, 58

wrovata, 54, 65, 200, 216, 217, 234; Pl. 23,
figs. ga—c

kilabiyaensis, 63, 194, 218; Pl. 17, figs.
4a-C

kolchidica, 192

lacerti, 190, 191

lensiformis, 190, 219

loeblichi, 59, 65, 66, 192, 193, 218-220;
Pl. 23, figs. 1a—c

marginodentata, 192, 202

mckanna, 170

membranacea, 56, 57, 203, 205, 207, 208,
210, 216, 227, 228

Globorotalia monmouthensis, 151

nicoli, 64, 65, 206, 220, 221

occlusa, 55, 56, 59, 63-65, 198, 221-223,
245, 247; Pl. 20, figs. 2a—-d; Pl. 22, figs.
4a—C

pentacamerata, 58, 59, 170

perclara, 63-65, 223, 224, 235; Pl. 21, figs.
2a—C

planoconica, 58, 209, 252

praenartanensis, 190, 192
prolata, 58
pseudobulloides, 27, 30, 31, 40, 54, 56, 57,
59, 63-65, 151, 154, 155, 204, 205, 216,
224-227, 234, 236, 237, 241; Pl. 18, figs.
3a-c
pseudomenardit, 25, 26, 28, 31, 55, 59, 63-
65, 204, 207, 209, 210, 216, 225, 227-229;
Pl. 17, figs. 7a—8c
Subzone, 60, 65, 156, 208, 222, 229, 230,
232, 233, 244, 253, 255
Zone, 172, 178, 185, 208, 210, 222, 220,
230
pseudoscitula, 55, 59, 158, 230
var. elongata, 209, 252
pseudotopilensis, 58, 211, 212
pshadae, 120
pusilla, 231%
group, 231
laevigata, 25, 64, 65, 229, 230, 231, 233;
Pl. 17, figs. 12a—c
mediterranica, 64, 65, 230-232, 233;
Pl. 19, figs. 3a—c
pusilla, 25, 26, 64, 65, 187, 230, 231, 232,
233; Pl. 17, figs. 11a—c
Subzone, 60, 64, 231, 242, 255
pusilla Zone, 208, 233, 242
quadrvata, 27, 54, 63-65, 151, 197, 198, 226,
227, 233, 234; Pl. 18, figs. 4a—c
quetva, 192, 219, 251

Globorotalia reissi, 213

vex, 51, 55, 57, 192, 202, 203
Zone, 202, 250
yvugosoaculeata, 235
sibaiyaensis, 65, 194, 224, 235; Pl. 23,
figs. 6a—c
simulatilis, 54-59, 192, 198, 202, 222
sp., 64, 65, 253; Pl. 23, figs. 8a—d
stvabocella, 170, 172, 215
subbotinae, 192
cf. subbotinae, 54, 58
thebaica, 58
tortiva, 180
tyibulosa, 54, 63-65, 212, 227, 236; Pl. 18,
figs. 2a—c
tyichotrocha, 194
tyvinidadensis, 25-27, 30, 31, 40, 54, 56, 63,
158, 224, 227, 236-238, 241, 242; Pl. 18,
figs. 7a—c
Zone, 165, 237
tyiplex, 59, 219, 220
tvoelsent, 65, 66, 210, 238, 239; Pl. 17, figs.
1oa—c

284

uncinata, 240, 242
carinata, 63, 64, 239, 240, 242; Pl. 10,
figs. ta—d
Subzone, 60, 64, 184, 199, 233, 242, 255
uncinata, 25, 26, 30, 31, 63, 64, 187, 198,
224, 232, 235, 237, 240-242; Pl. 18,
figs. ta—c; Pl. 19, figs. 2a—c
Zone, 237, 242
varianta, 59, 225
velascoensis, 37, 40, 42, 50, 54-59, 64, 189,
194, 196, 222, 242-244, 246-248
/ acuta Zone, 27
aff. var. acuta, 27, 189, 248
var. acuta, 189
caucasica, 31, 64, 242-244, 247, Pl. to,
figs. 6a—c
group, 202
parva, 31, 55, 64, 190, 202, 244, 245, 247;
Pl. 20, figs. 4a—d

Globorotalia velascoensis var. avagonensis 243

247

var. parva, 244, 245

velascoensis, 30, 31, 55, 57, 59, 63-65,
189, 196, 203, 229, 243, 245, 246-249,
ZO; ele 20) ee SHES 0-7) ele lo
fig 3.

Zone, 27, 31, 32, 43, 49, 50, 60, 64, 65,
157, 159, LOL, LOS, 172i 7OrSoinel So,

INDEX

(Tvuncorotalia), 185, 186
acuta, 244, 245
aequa, 192, 219
group, 192
marginodentata, 192
simulatilis, 192, 219, 220
angulata, 195
Globorotalia (tvuncorotalia) wicoxensis, 250
velascoensis, 194, 246
velascoensis, 246
Globorotaliidae, 185
Globorotaliinae, 185
Globorotaloides, 187
Globotruncana, 14, 20, 27, 35, 37-39, 54-56,
60, 62, 63, 66, 68-74, 84, 86-90, 92, 118,
I20, 124, 125, 128, 131, 133, 134, 136, 141
146, 147, 149, 152, 153, 186-189, 248, 250
adamsi, 61, 75, 76, 94, Pl. 8, figs. 2a—d
aegyptiaca, 38, 54-57, 70, 78-80, 131
aegyptiaca, 47, 48, 54, 61, 62, 76-80, 81,
112, 125; Pl. 3, figs. 4a—d; Pl. 4, fig. x
duwt, 61, 62, 78, 79, 80, 81; Pl. 3, figs.
5a—c
var. duwt, 37, 48, 54, 56, 78, 80,
var. I, 54, 56, 78
ansavii, 56
arabica, 61, 62, 71, 81-83, 87, 116, 145;
Pl. 6, figs. 3a—d; Pl. 11, fig. 4

arca, 38, 47, 48, 54, 56, 58, 59, 61, 62, 71,
79, 83-86, 91, 97, 99. 102, 122, 124, 127,
128, 120, 131, £33, 135» 143) E4Onmeleee

185, I90, 193, 196, 197, 199, 200, 201,
AO, AN, ZUR, Busy, Luldy, QAA, P27, BPE).

230, 234, 239, 244, 245, 248, 252, 253,

255-258
whitet, 55, 58, 65, 66, 187, 212, 249, 250,
251; Pl. 23, figs. 3a—-c
wilcoxensis, 51, 54, 55, 65, 187, 189, 192,
211, 212, 220, 249, 250-252, 258; Pl. 23,
figs 5a—c
var. acuta, 188
Zone, 32, 42, 50, 60, 65, 66, 157, 161, 168,
172, 174, 178, 193; 203; 230, 250) 252,
255, 257, 258
woodi, 65, 252, 253; Pl. 23, figs. 2a—c
Zone, 39
(Acarinina), 171
quetra, 219, 220
soldadoensis, 212
(Astrovotalia), 185, 187
stellaria, 185
(Globorotalia), 185, 186
compressa, 224
pseudobulloides, 225
(Globorotalia?) pusilla laveigata, 229
pusilla, 232

figs. 1a—2
ayca, 83, 85
cayibica, 85, III, 112
var. contusa, 90
var. esnehensis, 38, 54, 98, 99
bahijae, 61, 62, 82, 86, 87; Pl. 6, figs. 2a—d
boll, 85, 128, 129
calcavata Zone, 257
calicifovmis, 37, 56, 57, 76, 89, 92, 98,
99
caliciformis, 76
| intermedia group, 110
canaliculata, 56, 142
var. ventricosa, 143
Globotvuncana citae, 68, 120
convacata, 79, 82, 87, 129, 143, 144
conica, 48, 57, 61, 62, 74, 87-90, 99, 102,
126, 131, 135; Pl. 12, figs. 2a—d
caliciformis, 89
aff. conica, 87
cf. conica, 88-90
conica var. plicata, 89, 92

INDEX

contusa, 37, 56, 71, 89, 90, 92
contusa, 48, 61, 62, 89, 90-93, 94, 96, 97,
107; Pl. 7, figs. 2a—-3c
group, 74, 93, 94, 107, 110
patelliformis, 48, 61, 62, 76, 89, 93-95;
Pl. 8, figs. ta—c
sensu Troelsen, 92, 107, 109
scutilla, 61, 89, 92, 94, 95, 110
witwickae, 61, 92, 93, 95-97, 107; Pl. 7,
figs. La—c
convexa, 76, 85, 97
cf. convexa, 61, 62, 97, 98; Pl. 1, figs. 5a—c
cretacea, 27, 37, 54, 56, 58, 59, 84, III, 124,
I25, 128, 129
elevata, 102, 135, 138
stuartiformis, 85, 135, 137, 138
esnehensis, 37, 38, 48, 56-58, 61, 62, 98—
100, Io1, 102, 119, 126, 127, 131, 136;
Pl. 12, figs. 1a—d
Zone, 48, 60, 62, 67, 80, 81, 83, 85, 87, 93,
94, 98, 100, 102, II3, I15, 116, 120,
L227 eI 23 e125, 27, ashe lseymi4am, 145)
146, 150, 151, 255-257
fareedi, 47, 48, 61, 62, 74, 99, 100-102, 129
Pl. 9, figs. 4a—d
fornicata, 76, 105-107, 122
ackermanni, 61, 102, 103, 106; Pl. 14,
figs. 3a—5d
Globotrvuncana fornicata cesavensis, 61, 103—
105, 106, 141; Pl. 13, figs. 3a—4c; Pl. 14,
figs. 6a—c
fornicata, 27, 61, 76, 92, 94-97, 103, 104,
105-108, 109, 110; Pl. 13, figs. 5a—c; 6;
Pl. 14, figs. 1a—c
globulocamerata, 61, 107, 108, 109;
Pl. 13, figs. 1a—c; Pl. 14, figs. 2a—c
group, 47, 61, 93, 104, 107, 109, IIo, 141,
142
manaurensis, 61, 106, 109-110; Pl. 13,
figs. 2a—c
plummerae, 104, 107
var. contusa, 96
Zone, 47, 60, 61, 76, 80, 86, 93, 95, 96, 98,
102, 103, IO8—-III, 113, 122, 124, 125,
127, 136, 139, 140, 142, 144, 151, 255-
257
fundiconulosa, 61, 87, 110, 111
gagnebini, 47, 48, 54, 59, 61, 62, 78, 79, 85,
111-113, 114, 115, 125, 144; Pl. 2, figs.
ta—4d; Pl. 3, figs. 1a—d, 3a—-d, 6
cf. gagnebini, 61, 113; Pl. 3, figs. 2a—d
ganssevi, 56-59, 78, 114-119
assemblage Subzone, 139

285

dicarinata, 61, 114, 115, 116, 118, Pl. 5,
figs. 4a—d
Zonule, 115

gandolfii, 61, 115, 116, 118, 127; Pl. 5,
figs. 2a—d

ganssert, 47, 61, 116, 117-119, 120, 123,
127, 129) (Pll 5, figs: wa-d; el ra;
fig. 3

group, 54, 61, 62, 78, 118, 127

subgansseri, 118, 119, 120; Pl. 5, figs. 3a—d

Zone, 47, 48, 60-62, 67, 76, 80, 81, 83, 86,
87, 90, 93, 94, 98, 100, 102, 108, 109,
III, I13, 115, 116, 118-120, 122, 123,
125, 127, 131, 132, 136, 139-146, I50,
I51, 255-257

globigerinoides, 37, 50, 124

Globotvuncana havanensis, 47, 48, 61, 62, 68,

120, 121, 152

helvetica, 68

imbricata, 107

intermedia, 57, 66, 98, 99
intermedia, 67

lamellosa, 143

lapparenti, 56, 85, 125, 129, 142
lapparenti, 57, ©7, 107, 110, 142

Zonule, 140

tvicavinata, 57, 142

leupoldi, 47, 61, 62, 71, 85, 121, 122, 126,
129; Pl. 1, figs. 4a—c

linnet, 142
marginata, 122
stuavtt, 122, 133
tricavinata, 142

linneiana, 85
caliciformis, 89, 92
linneiana, 27, I10, 143
tvicavinata, 143

lugeont, 48, 61, 62, 83, 112, 120, 122, 123;
Pl. 6, figs. ra—d; Pl. 11, fig. 2
var. angulata, 123, 145

marginata, 71, 129

marviat, 61, 123, 124

mariet, 48, 61, 62, 124, 125, 129

mayaroensis, 57, 66, 67

monmouthensis, 117, 118

orientalis, 61, 62, 74, 85, 89, 99, 125-127,
131; Pl. 12, figs. 4a—d

pendens, 112

planata, 67

pooleyi, 56

pseudocretacea, 54, 125

pseudofornicata, 56

quabeliatensis, 56

286 INDEX

quadrata, 56
var. plata, 56
vepanda, 82, 87
vosetta, 56, 58, 59, 79, 84, 85, 100, 122, 125,
128, 129, 133-136
Globotrvuncana rosetta insignis, 100, 101, 129
pembergeri, 101
pettersi, 61, 118, 127, 129
cf. vosetta petterst, 127
rosetta vosetta, 27, 59, OI, 101, 118, 125, 128—
130, 133; Pl. 8, figs. 3a—-d
sharawnaensis, 61, 62, 74, 89, 126, 130,
131
sigali, 135
stuartt, 57, 71, 89, 129, 131, 133-139
conica, 89, 135
elevata, 135, 138
group, 47, 69, 85, 128, 138
parva, 48, 57, 61, 62, 79, 131-133, 134-
136,; Pl. 9, figs. 2a—d
stuart, 54, 59, 61, 89, IOI, 102, 123, 132,
133-136, 138, 139; Pl. 8, figs. 4a-d;
Pl. 9, figs. 1a—d
stuartiformis, 54, 61, 85, 125; 133-135,
136-139, 140; Pl. 9, figs. 3a—d
subspinosa, 61, 133-136, 138, 139, 140;
Pl. 10, figs. 2a—3¢
Zone, 144
subcivcumnodifer, 61, 62, 140, 141
subspinosa, 139
sudvensis, 56
var. parallela, 56
thalmanni thalmanni, 129
tilevt Subzone, 115
tovensis, 56
tvicavinata, 144
colombiana, 61, 79, 81, 141, 142, 143, 144
tvicavinata, 27, 28, 47, 61, I10, 141, 142,
143, 144
undulata, 139 ,140
ventricosa, 47, 50, 61, 79, III, 112, 125, 129,
143, 144
cavinala, 143, 144
convacata, 143
Globtvuncana ventricosa primitiva, 143, 144
ventyicosa, III-113, 143, 144
wiedenmayert magdalenaensis, 110, 111
wiedenmayert, 110, III
youssefi, 61, 62, 83, 144, 145; Pl. 6, figs.
4a—d
sp., 61, 62, 145, 146; Pl. 1, figs. 6a—c
(Globotruncana), 83, 87, 90, 93, 95, 105, 120,
133, 137, 139

arca, 83
citae, 120
contusa, 90
patelliformis, 93
scutilla, 95
elevata stuartiformis, 137
fornicata, 105
plummerae, 105
vosetta, 133
sp. aff. conica, 87
stuarti, 133
stuartt, 133
stuartiformis, 137
subspinosa, 139
subspinosa, 139
(Marginotruncana), 67, 90
contusa, 90
intermedia, 67
(Rugoglobigervina), 87, 140, I4I, 140-149,
152
civcumnodifer circumnodifer, 141
subciycumnodifer, 140, 141
glaessnevi glaessnevi, 146
subglaessneri, 146
loettervli loettevli, 147
subloetterli, 147
macrocephala macrocephala, 147
submacrocephala, 147
ornata ornata, 147
subornata, 147
pennyi pennyt, 148
subpennyi, 87, 140, 141
Globotruncana (Rugoglobigerina) petaloidea, 52
petaloidea, 152
subpetaloidea, 152
votundata votundata, 148
vugosa VYUgOSa, 149
(Rugotvuncana, 114, 117, 141
ganssevi, 117
dicavinata, 114
subcivcumnodifer, 14%
tilevi, 141
SEst5 70
Zone, 35, 43, 55
| Guembelina Zone, 35-36, 39, 99
Globotruncanella, 68, 71
Globotruncanidae, 66
Globotvuncanita, 68, 71
Goffint, puits de, 26
Goniatheutis quadvata, 17
Greenish and ashen-grey paper-like shales,

33
Guayaguayare formation, 53, 118

INDEX 287

Gubbio section, 165, 237

Gublervina, 20

Guembelina, 38, 39, 60

Gulf and Atlantic Coastal plains, 165, 190,
HOR 200,210), 212, 210, 219) 223, 7224,
230

Gulpen chalk, 17, 18

Gurnah section, 42, 58

Hainin, Trenchéede, 26
Hantkenina, 244
Hastigerina, 58
aspera, 58
micra, 58
Hedbergella, 14, 20, 28, 38, 56, 57, 60, 62, 63,
72, 73, 150, 152-155, 163-165, 187, 188,
226, 234, 240
hesst compressiforvmis, 48, 61, 150, 151
hesst, 48, 61, 62, 151
mattsont, 48, 61, 151
monmouthensis, 48, 61, 62, 151
Hedbergella petaloidea, 48, 61, 62, 152
Hedbergellinae, 150
Heersian, 23, 24, 256, 257
Heervian, 18
and Aachen sands, 18
Helvetoglobotvuncana, 68, 71
Hendaye region, 92, 136
Heretaugan stage, 247
Hetevohelix, 20, 60, 62
Hippurites, 20
Hoplitoplacenticeras, 16, 17, 40
awadi, 40
vavt, 16, 17
ZONE TO. 17
Hornerstown formation, 161, 165, 200, 221,
224

Ilerdian, 23, 29, 157, 161, 178, 185, 206, 212,
22222) 258
Infra-Heersian, 24
Inocerami, 33
Inocevamus, 33
vegularis, 43
Isocardia, 40, 47
chargensis, 40
(Isocardia) chargehensis, 47

Jicara formation, 190
Jurassic, 73, 153, 155

Kharga Oasis, 10, 40, 46, 49, 55, 196, 212, 234
paper shale member, 45

Kosseir, 41, 44-46, 49, 81
variegated shales, 41, 44

Kuglerina, 146, 148, 149

Kkunrade chalk, 17

Landen Basin, 26
Landenian, 23-29, 31, 37, 42, 58, 157, 161,
172, 184, 185, 196, 200, 208, 212, 215, 216,
222, 230, 236, 239, 256-238
Lantern marl, 118
Laversines, 15, 19, 22
Leon, 93
Libya group, 254
Libyan, 10, 32-34, 41, 51
Libycoceras, 33, 40, 41, 52, 53, 254, 256
berisensis, 52, 53
Subzone, 52, 254, 256
chargense, 53
ismaeéli, 40, 41, 53
phosphaticus, 53
Libysche, stufe, 222
Lignites du Soissonnais, 23
Limbourg, 15, 18
Lizard Springs formation, 25, 53, 165, 174,
176, 178, 181, 185, 193, 196, 202, 208, 210,
229, 230, 233, 234, 237, 242, 249, 250
Lloydminster shale, 147
Lodo formation, 202, 221
Londinian, 35
Lopha villet, 52, 53
Zone, 52, 61, 254, 255, 257
Lower Eocene, 8, 10-13, 15, 22-25, 28, 29,
31-44, 49-55, 55-58, 66, 156, 157, 161, 168,
WF}, WGP WIIAL, WF, I7fer, WtsKO}, Wests IKOTO), IT,
193, 196, 199, 202, 203, 206, 209, 212, 213,
216, 217, 219-222, 224, 234, 234, 236, 238,
239, 243, 244, 248-252, 257, 258
Lower Esna shales, 49, 51
Lower Owaina shale member, 11, 49, 62, 63,
254, 256
Lower Sharawna shale member, 11, 46, 47,
61, 254, 250
Lucina thebaica, 53
Zone, 53, 66, 254, 257
Luplin Basin, 96
Lutetian, 243-245

Maestricht, 15, 19
Maestricht chalk tuff, 16
tuff, 17
tuffaceous chalk, 17, 18

288 INDEX

Maestrichtian, 12, 13, 15-23, 28, 33, 35-43,
45-49, 53-58, 61-63, 73, 74, 76, 78-83, 85,
87, 90, 92-100, 102, 103, 105, 107-111, 113,
I15, 116, 118-125, 129, 133, 135, 136, 138-
152, 155, 160, 163, 164, 170, 181, 212, 218,
226, 234, 254, 256, 257
/ Danian boundary, 12, 21, 39, 41, 55,
257

Madruga formation, 208, 251

Mahamid disteict, 12

Manaure shale, 95, 110, 141

Maqfi section, 36, 42, 56, 58, 210-212

Marginotruncana, 68, 70, 71, 92, 120, 136
citae, 120
contusa, 90
intermedia, 67
stuarti, 98, 136

Marne blanche, 157

bleue, 206, 221

Mellaha section, 99, 125

Mendez shale, 85, 90, 92, 160

formation, 90, 234

Mesozoic, 20, 41, 256, 257

/ Cainozoic boundary, 15, 41, 256, 257

/ contact, 21

Meudon chalk, 16, 17
conglomerate, 22

Middle Owaina chalk member, 11, 50, 64, 254,
256

Middle Sharawna marl member, 11, 47, 48,
61, 62, 254, 256

Midway group, 181, 205, 227

Mons, 25, 26

Mont Cayla, 29, 157, 206, 212, 221,

Montian, 20, 23-29, 35, 37, 40, 41, 55, 185,
190, 196, 222, 229, 230, 233, 234, 256—
258

Naheola formation, 217
Nanafalia formation, 161, 216, 217, 224, 236,
239
Nannoplankton, 239
Nautilus danicus, 25
desevtorum, 40
Navarro group, 79, 107, 149
Navet formation, 174
Nekhl section, 38, 40, 57, 208, 251
Neocomian, 16
Neoflabellina vugosa, 39
Nile Valley, 8-10
Non-fossiliferous Zone, 52, 60, 254, 255
Non-megafossiliferous Zone, 53, 66
Nostoceras sp., 40

Nouvelles chalk, 16
Noxontown fauna, 224
Nubia formation, 12, 42, 45
group, 46, 254
sandstone, 8, II, 12, 14, 32, 34, 41, 44
plateau, 8
and variegated shale, 11, 44-46, 60, 254,
255
variegated claystones and sandstones, 36
Nummulites, 19, 32, 66, 257
deserti, 32
Nummulitic limestone, 12, 34
beds, 32
transgression, 22

Oligocene, 38

Operculina, 32, 66, 257
limestone, 10

Orbitoides tissoti, 40

Ostrea hypoptera, 43

Zone, 43, 53, 65, 254, 256

Overwegischichten, 32, 40

Owaina, II, 12, 38, 42, 45, 49, 50, 79, 81, 89,
I1I5, 120, 123, 145, 148, 150, 156-159, 161,
167, 168, 172, 174, 176, 178, 180, 183, 184,
190, 193, 194, 196, 198, 200, 201, 205, 206,
208, 210, 212, 214, 215, 217, 220-222, 224,
227, 228, 230, 231, 233, 235, 236, 239, 240,
242, 243, 245, 248, 250, 251, 253

Owaina shale formation, 45, 49, 50, 51, 254,
256

Oyster limestone, Io, 12, 34

Pachydiscus neubergicus, 16-18
Zone, 16-18

Paderno d’Adda section, 165, 176, 185, 208,
22275220 2 On 280)

Pale Greda formation, 178, 252

Paleocene, 12, 13, 15, 22-44, 49-51, 53, 55,
64, 65, 80, 156-161, 163-166, 168-170, 172,
174, 176-178, 180, 181, 185, 190, 193, 194,
196, 198, 201, 205-210, 212, 214, 216-224,
226, 227, 229, 230, 233, 234, 236-239, 242,
244, 245, 248, 250-254, 256-258
/ Eocene boundary, 15, 258

Pamietowo well ,169

Papagallos shales, 85, 144

Parguera limestone formation, 140

Paris Basin, 15, 16, 19, 22-24, 28, 29, 85,
124

Passage beds, 33, 34

Pecten favafraensis, 118

marl, 118

INDEX 289

(Chlamys) mayereymari, 47, 53
marl, 12, 118
Zone, 52, 254, 256
Subzone, 52, 62, 254, 256
Pholadomya oblittevata, 24
Phosphate beds, 12
formation, 12
Phosphatic chalk of Ciply, 17
Physa gigantea, 24
Pisolitic limestone, 16, 19, 22
Placenticeras bidorsatum Zone, 16
Planoglobulina, 20, 60
Planorotalia, 185, 187
Planorotalites, 185, 187
Planulina membranacea, 185
Pleistocene, 9, 13, 249
Plicatula aschersoni, 40
instabilis, 40
Pliocene, 9, 210
Plummerita, 20
Praeglobotyvuncana, 71-73, 90, 120, 150, 187
gautievensis, 140
Subzone, 140
hesst compressifovmis, 150
hesst, 151
mattsont, 151
mayaroensis, 136
Zone, 136
(Hedbergella), 151, 152
monmouthensis, 151
petaloidea, 152
(Praeglobotruncana), 67, 120
havanensis, 120
intermedia, 67
mayaroensis, 07
Prahova Basin, 93
pseudobulloides Subzone, 27
Pseudogloborotalia, 198, 247
Pseudoguembelina, 20, 60
Pseudotextularia, 20, 60, 62
elegans Zone, 136
Puits Goffint, 26
Pulinulina, 68, 69, 83, 84, 90, 91, 142, 185,
186, 227, 246, 247
arca, 68, 69, 83, 84, 91
var. contusa, 90
membyanacea, 227
menardiw var. tumida, 185, 186
tvicavinata, 142
velascoensis, 246, 247

Qabeliat section, 37, 56, 78, 79, 92

Oift area, 46

Quena, 35, 46
Ouseir formation, 44

Racemiguembelina, 20, 60
Radiolites, 20
Reading Beds, 24, 28
Recent, 9, 13
Red Sea Coast, 41, 49
Redbank formation, 151, 152
Rilly, Calcaire de, 23
Rio Yauco mudstone formation, I15, 140,
150, 151
Ripley formation, 98
Rosalina, 69
canaliculata, 69
linnet, 121, 142
type 2, 142
type 5, 121
mut. caliciforme, 92
marginata, 68, 69
stuarti, 68, 69, 121, 133, 134
Rosalinella, 68-70, 124, 186
appenninica, 69
globigeriniodes, 123, 124
var. sublaevigata, 123, 124
linnet, 69
linneiana, 68
stuarti, 69
velascoensis, 69
Rotalia, 69
like Globorotalias, 206, 216
Rotalina truncatulinoides, 185
Rotalipova, 69-71
appenninica, 107
Rotaliporidae, 150
Rugoglobigerina, 14, 20, 28, 38, 56, 57, 60, 62,
63, 66, 70, 71, 73, 87, 120, 141, 146, 147,
149, 152, 153, 155, 159, 163-165, 172, 181,
LOM 22 0227-2234
cvetacea, 57
esnehensis, 57
glaessnevi, 48, 61, 62, 146
jevseyensis, 152
sp. cf. R. jervseyensis, 58, 59
loetterli, 48, 61, 62, 147
macrocephala, 48, 61, 62, 147, 181
Rugoglobigerina macrocephala macrocephala,
147
ornata, 147
pennyt, 48, 61, 62, 148
pustulata, 48, 61, 62, 148

290 TANG ES

veicheli pustulate, 58, 69, 148

votundata, 48, 61, 62, 148

rugosa, 47, 48, 59, 61, 62, 148, 149
| Globotruncana rosetta Subzone, 140
pennyi, 148
votundata, 146, 148
vugosa, 149
subrugosa, 114

scotti, 150

Rugotrvuncana, 68, 70, 118, 141

ellist, 141

ganssevi, 117

havanensis, 120

intermedia, 67

mayaroensis, 67

skewesae, 76, 78, 79

tilevi, 68, 141

Sables de Bracheux et de Chalons-sur-Vesle,
23

Safaga area, 41, 46, 49, 103

Salina formation, 252

Salt Mountain limestones, 190, 200, 222

Santonian, 16, 35, 41, 74, 76, 82, 90, 107, 108,
I10, 138-140, 142, 144

Schackoina, 20

Seelandian, 23-25, 256, 257

Selma chalk, 125

Senonian, 15-19, 27, 28, 32, 33, 35, 37) 41,
139, 154, 257

Sens, 15

Sézanne, Travertine de, 22, 23

Sharawna shale formation, 45, 46, 47-49, 108,
118, 254, 256

Sibaiya phosphate, 8, 44-47

formation, 10, 14, 45, 46, 60, 254-256

Sinai, 34, 37, 38, 56, 57, 78, 79, 81, 90, 92, 99,
100, 144, 208, 212, 251

Siphogenerinoides bramlettei Zone, 120

Skrivekridt, 226

Soissonnais, Lignites de, 23

Soldado formation, 174, 190, 193

Sparnacian, 23-25, 27, 28, 41, 157, 161, 200,
215, 222, 256-258

Spherolites, 20

Spiennes chalk, 16

Subbotina, 153, 154, 155, 180

Sudr section, 37, 56, 78, 79, 92

Sylvania guyot, 250

Syrian arc movement, 38

Tamaulipas formation, 90

Tampico Embayment, 237, 250
Taramsa / Tukh area, 35
Tarfaya province, 108, 140
Taylor formation, 107, 108
marl, 129
Terebratulina gracilis, 46, 47, 53
Subzone, 52, 61, 254, 256
Tertiary, 7-10, 12, 13, 15, 21, 36-39, 41, 164,
INS, WCO), Bi, Divi, Zz
Tethyan region, 7, 13, 14
Texanites delawavense Zone, 16
Thalmanninella, 70
Thanet Beds, 28
Thanetian, 23-28, 41, 181, 185, 189-200, 217,
222, 227, 248, 2560-258
Thebes, 42
calcareous shale member, 11, 37, 42, 45,
51, 65, 254, 257
formation, 42, 45, 49
limestone, II, 45, 51, 65, 66, 196, 216, 254,
257
and calcareous shale formation, 8, 51,
52, 254, 257
Ticinella, 70
Travertine de Sézanne, 22, 23
Trenchée de Hainin, 26
Trigonarca, 40
gauldrina, 40, 43
Trinitella, 14, 20, 60-63, 66, 71, 149
scotti, 48, 61, 149, 150
Truncatulina, 69
Truncorotalia, 38, 39, 186, 189, 198, 243, 247
angulata, 197
avagonensis Caucasica, 244
colligera, 57
cvassata aequa, 57, 190, 192
esnaensis, 57, 58
simulatilis, 57, 58
spinulosa, 57, 58
velascoensis, 57, 58, 246
wilcovensis, 37, 251
Zone, 39, 190
Truncorotaloides, 244
Tuffaceous limestone of Maestricht, 18
Tuffeau de Ciply, 16, 23, 25, 26
de la Fére, 23
Turborotalia, 186, 187, 204
Turonian, 16, 38, 74, 108, 135
Tylocidaris vexilifera Zone, 181

Um Elghanayem section, 55, 212
Um El-Huetat section, 41, 81, 103

INDEX 291

Upper Cretaceous, 7-10, 12, 13, 15, 18-21,
153, 164, 172, 181, 184, 189, 190, 248, 250,
257

| Lower Tertiary, 7—10, 12, 13, 15, 254
Owaina shale member, I1, 51, 64, 254, 256

Upper Sharawna shale member, 11, 48, 61,

62, 254, 250

Vaux-sous-Laon, 23

Velasco formation, 160, 165, 172, 176, 181,
184, 190, 198, 199, 206, 221, 222, 234, 239,
247

Vemella (Roudaireia) drur. 40

Vigny, I5, 19, 22

Vincentown formation, 157, 200, 222

Wadi Danili, 79

El-Sharawna, 45, 83, 85, 87, 92, 94, 98, 99,
102, 105, III, II3, 116, 118, 122, 125,
727), WAKO), ist, Iss, isXo). ieks}, UO Koy, iyi),
146-152

Mellaha, 79

Quena, 34

Sudr, 37

Wangschichten limestone, 122
Western Desert, 8, 10, 36, 39, 42, 49
Oases, 10, 32, 34
Sinai, 37, 56
Wilcox group, 251
Wills Point formation, 205
Woolwich and Reading Beds, 24, 28

Ypresian, 24, 32, 37, 42, 52, 58, 236, 258

Zone of conical Globorotalias, 168, 174

PLATE xz
(All figures approximately » 80)
a, dorsal view ; b, side view ; c, ventral view

Fics. ta—c, 2. Globotruncana arca (Cushman). Hypotypes, from S.4, Abou Saboun
section, showing variation in the degree of development of the ventral keel on the last chambers.
P.45517

Fics. 3a-c. Transitional stage between Globotruncana arca (Cushman), and Globo-
truncana convexa Sandidge ; from S.23, W. El-Sharawna section. P.45517

Fics. 4a-c. Globotruncana leupoldi Bolli. Hypotype, from 5.18, W. El-Sharawna
section. P.45545

Fies. 5a-c. Globotruncana cf. convexa Sandidge. Hypotype, from S.20, W. El-Sharawna
section. P.45526

Fics. 6a-c. Globotruncana sp., from S.20, W. El-Sharawna section. P.45566

Bull. B.M.(N.H.) Geol. Suppt. 2 PLATE 1

PLATE 2
(All figures approximately x71)

a, dorsal view ; b, d, side views ; c, ventral view
Fics. 1a-4d. Globotruncana gagnebini Tilev. Hypotypes 1 and 2, from S.16, W. EI-
Sharawna section ; hypotype 3 which is a transitional stage to G. ventricosa White, is from
S.18, W. El-Sharawna section ; hypotype 4 from S.4, Abou Saboun section. P.45538, P.45539

Bull. B.M.(N.H.) Geol. Suppt. 2

é
5
{

PLATE 3

(All figures approximately x 75)
a, dorsal view ; b, d, side views ; c, ventral view

Fics. ta—d, 3a-d, 6. Globotruncana gagnebini Tilev. Hypotype 1, from S.11, G.
Owaina section ; hypotype 3 from S.18, W. El-Sharawna section ; hypotype 6 from S.16,
W. El-Sharawna section. P.45538

Fics. 2a-d. Globotruncana cf. gagnebini Tilev, from S.4, Abou Saboun section, showing
a gently coned dorsal side different from that of the typical form. P.45539

Fics. 4a-d. Globotruncana aegyptiaca aegyptiaca (Nakkady). Hypotype, from S.16,
Gebel Owaina section, showing the distinctly petalloid equatorial periphery and the cruciform
arrangement of the chambers in the last whorl. P.45512

Fics. 5a-c. Globotruncana aegyptiaca duwi Nakkady. Hypotype, from S.16, Gebel
Owaina section, showing the tripartite appearance of the test, the rapid increase in size of
chambers and the rough surface. P.45514

PLATE 3

Bull. B.M.(N.H.) Geol. Suppt. 2

PLATE 4

Fic. 1. Globotruncana aegyptiaca aegyptiaca Nakkady, from S.16, Gebel Owaina
section.

Axial section of hypotype, approximately x 247, plane polarized light.

Fic. 2. Globotruncana gagnebini Tilev, from S.17 W. El-Sharawna section.

Axial section of hypotype, approximately x 210, plane polarized light.

Bull. B.M.(N.H.) Geol. Suppt. 2 PLATE 4

PLATE 5

(All figures approximately x 72)
a, dorsal view ; b, d, side views ; c, ventral view

Fics. 1a-d. Globotruncana gansseri gansseri Bolli. Hypotype, from S.18, W. El-
Sharawna section. P.45543

Fics. 2a-d. Globotruncana gansseri gandolfii subsp. nov. Holotype, from S.21, W. El-
Sharawna section. P.45541

Fics. 3a-d. Globotruncana gansseri subgansseri Gandolfi. Hypotype, from S.16,
Gebel Owaina section. P.45544

Fics. 4a-d. Globotruncana gansseri dicarinata Pessagno. Hypotype, from S.16, Gebel
Owaina section. P.45540

Bull. B.M.(N.H.) Geol. Suppt. 2 PLATE 5

PLATE 6
(All figures approximately x 80)
a, dorsal view ; b, d, side views ; c, ventral view
Fics. 1a-d. Globotruncana lugeoni Tilev. Hypotype, from S.15, Gebel Owaina section.

P.45546
Figs. 2a-d. Globotruncana bahijae sp. nov. Holotype, from $.18, W. El-Sharawna

section. P.45518
Fics. 3a-d. Globotruncana arabica sp. nov. Holotype, from $.22, W. El-Sharawna

section. P.45515
Fics. 4a-d. Globotruncana youssefisp.nov. Holotype, from $.16, Gebel Owaina section.

P.45564

Bull. B.M.(N.H.) Geol. PLATE 6

PLATE 7
(All figures approximately x 76)
a, dorsal view ; b, side view ; c, ventral view

Fics. ta-c. Globotruncana contusa witwickae subsp. nov. Holotype, from $.4, Abou
Saboun section. P.45524

Fics. 2a-3c. Globotruncana contusa contusa (Cushman). Hypotypes, from S.18, W.
El-Sharawna section. P.45521

Bull. B.M.(N.H.) Geol. Suppt. 2 PLATE 7

PLATE 8
(All figures approximately x 76)
a, dorsal view ; b, d, side views ; c, ventral view

Fics. ta-c. Globotruncana contusa patelliformis Gandolfi. Hypotype, from S.18, W.
El-Sharawna section. P.45522

Fics. 2a-d. Globotruncana adamsi sp. nov. Holotype, from S.4, Abou Saboun section.
P.45511

Fics. 3a-d. Globotruncana rosetta rosetta (Carsey). Hypotype, from S.16, W. EI-
Sharawna section. P.45552

Fics. 4a-d. Globotruncana stuarti stuarti (de Lapparent). Hypotype, from S.18,
W. El-Sharawna section. P.45556

Bull. B.M.(N.H.) Geol. Suppt. 2 PLATE 8

‘ .-

sy Aw? oe ry

PLATE 9
(All figures approximately x 76)
a, dorsal view ; b, d, side views ; c, ventral view

Fics. ta-d. Globotruncana stuarti stuarti (De Lapparent), transitional to Globotrun-
cana stuarti parva Gandolfi. Hypotype, from S.18, W. El-Sharawna section. P.45556

Fics. 2a-d. Globotruncana stuarti parva Gandolfi. Hypotype, from S.23, W. El-
Sharawna section. P.45555

Fics. 3a-d. Globotruncana stuarti stuartiformis Dalbiez. Hypotype, from S.18,
W. El-Sharawna section. P.45558

Fics. 4a-d. Globotruncana fareedi sp. nov. Holotype, from S.24, W. El-Sharawna
section. P.455528

Bull. B.M.(N.H.) Geol. Suppt. 2 PLATE 9

?

; 7

}

>

H
J

8,

PLATE to
(All figures approximately x 76)
a, dorsal view ; b, side view ; c, ventral view

Fics. ta—c. Transitional form between Globotruncana stuarti subspinosa Pessagno
and G,. stuarti stuarti (de Lapparent), from $.16, W. El-Sharawna section. P.45557

Fics, 2a-3c. Globotruncana stuarti subspinosa Pessagno. Hypotypes, from S.18,
W. El-Sharawna section. P.45559

PLATE 10

Bull. B.M.(N.H.) Geol. Suppt. 2

PLATE 11

Fics. 1a-b. Globotruncana contusa contusa (Cushman), from S.18, W. El-Sharawna
section.

a—Axial section of hypotype, approximately x 120, plane polarized light. b—same, crossed
nicols.

Fic. 2. Globotruncana lugeoni Tilev, from S.21, W. El-Sharawna section ; axial section
of hypotype, approximately x 187, plane polarized light.

Fic. 3. Globotruncana gansseri gansseri Bolli, from S.18, W. El-Sharawna section ;
axial section of hypotype, approximately x 440, plane polarized light.

Fic. 4. Globotruncana arabica sp. nov, from S.22, W. El-Sharawna section ; axial section
of paratype, approximately x 154, plane polarized light.

PLATE 11

Bull. B.M.(N.H.) Geol. Suppt. 2

PATE 12
(All figures approximately x 76)
a, dorsal view ; b, d, side views ; c, ventral view

Fics. ta-d. Globotruncana esnehensis Nakkady & Osman. Hypotype, from S.17, W.
El-Sharawna section. P.45527

Fics. 2a-d. Globotruncana conica White. Hypotype, from $.16, Gebel Owaina section.
P.45520

Fics. 3a-d. Globotruncana sharawnaensis sp. nov. Holotype, from S.20, W. EI-
Sharawna section. P.45553

Fics. 4a-d. Globotruncana orientalis sp. nov. Holotype, from $.18, W. El-Sharawna
section. P.45549

PLATE 12

Ze

Suppt.

B.M(N.H.) Geol

Bull.

IEA LUNAR Die aes)
(All figures approximately x 76)
a, dorsal view ; b, side view ; c, ventral view

Fics. 1a-c. Globotruncana fornicata globulocamerata subsp. nov. Paratype,
S.3, Abou Saboun section. P.45533

Fics. 2a-c. Globotruncana fornicata manaurensis Gandolfi. Hypotype, from
G.A 314 section. P.45535

Fics. 3a-4c. Globotruncana fornicata cesarensis Gandolfi. Hypotype 3, from
W. El-Sharawna section, and 4 from S.4, G.A 314 section. P.45530

Fics. 5a-6. Globotruncana fornicata fornicata Plummer. Hypotype 5, from
G.A 314 section, and 6, from S.3, Abou Saboun section. P.45531

from
S.14,
S.16,

Suray

Bull. B.M.(N.H.) Geol. Suppt. 2 PLATE 13

pratsh 9
a i

PLATE 14
(All figures approximately x 76)
a, dorsal view ; b, d, side views ; c, ventral view

Fics. ta-c. Transitional stage between Globotruncana fornicata fornicata Plummer and
Globotruncana fornicata globulocamerata subsp. nov. from $.4, Abou Saboun section.

P.45534
Fics. 2a-c. Globotruncana fornicata globulocamerata subsp. nov. Holotype, from

S.4, Abou Saboun section. P.45532
Fics. 3a-5d. Globotruncana fornicata ackermanni Gandolfi. Hypotype, from S.4,

Abou Saboun section. P.45529
Fics. 6a-c. Globotruncana fornicata cesarensis Gandolfi. Hypotype, from S.4, Abou

Saboun section. P.45530
Fics. 7a-c. Transitional stage between Globotruncana fornicata manaurensis Gandolfi

and Globotruncana tricarinata tricarinata (Quereau). P.45536

Bull. B.M.(N.H.) Geol. Suppt. 2 PLATE 14

PLATE 15
(All figures approximately x 76, except Ia-—c, X 116)
a, dorsal view ; b, side view ; c, ventral view

Fics. ta-c, 2. Globigerina kozlowskii Brotzen & Pozaryska. Hypotype, from S.7, Gebel
El-Kilabiya section. P.45579

Fics. 3a-c. Globigerina daubjergensis Brénnimann. Hypotype, from S.7, Gebel El-
Kilabiya section. P.45575

Fics. 4a-c. Globigerina triloculinoides parva subsp. nov. Holotype, from $.53, Gebel
Owaina section. P.45587

Fics. 5a-c. Globigerina haynesi sp. nov. Holotype, from S.64, Gebel Owaina section.
P.45576

Fics. 6a-c. Globigerina nodosa sp. nov. Holotype, from S.49, Gebel Owaina section.
P.45581

Fics. 7a-c. Globigerina triloculinoides Plummer. Hypotype, from $.38, Gebel Owaina
section. P.45586

Fics. 8a-c. Globigerina inaequispira Subbotina.. Hypotype, from S.49, Gebel Owaina
section. P.45578

Bull. B.M.(N.H.) Geol. Suppt. 2 PLATE 15

PLATE 16
(All figures approximately x 78)
a, dorsal view ; b, d, side views ; c, ventral view

Fics. 1a-d. Globigerina stonei Weiss. Hypotype, from S.68, Gebel Owaina section.
P.45585

Fics. 2a-c. Globigerina spiralis Bolli. Hypotype, from S.53, Gebel Owaina section.
P.45584

Fics. 3a-d. Globigerina velascoensis Cushman. Hypotype, from S.51, Gebel Owaina
section. P.45589

Fics. 4a-c.. Globigerina chascanona Loeblich & Tappan. Hypotype, from S.64, Gebel
Owaina section. P.45574

Fics. 5a-c. Globigerina mckannai White. Hypotype, from S.51, Gebel Owaina section.
P.45580

Fics. 6a-c. Globigerina alanwoodi sp. nov. Holotype, from S.43, Gebel Owaina section.
P.45567

Bull. B.M.(N.H.) Geol. Suppt. 2 PLATE 16

PLATE 17
(All figures approximately x 78)
a, dorsal view ; b, side view ; c, ventral view

Fics. ta—3c. Globorotalia compressa (Plummer). Hypotypes, from S.31, S.30, Gebel
Owaina section, and S.7, Gebel El-Kilabiya section respectively. P.45601-03

Fics. 4a-c. Globorotalia kilabiyaensis sp. nov. Holotype, from S.7, Gebel El-Kilabiya
section. P.45613

Fics. 5a-c. Globorotalia ehrenbergi Bolli. Hypotype, from $.37, Gebel Owaina section.
P.45605

Fics. 6a-c. Globorotalia imitata Subbotina. Hypotype, from S.7, Gebel El-Kilabiya
section. P.45611

Fics. 7a-8c. Globorotalia pseudomenardii Bolli. Hypotypes from S.39, Gebel Owaina
section. P.45622

Fics. ga-c. Globorotalia emilei sp. nov. Holotype, from $.33, Gebel Owaina section.
P.45606

Fics. 1oa-c. Globorotalia troelseni Loeblich & Tappan. Hypotype, from S.68, Gebel
Owaina section. P.45633

Fics. 11a-c. Globorotalia pusilla pusilla Bolli. Hypotype, from S.37, Gebel Owaina
section. P.45626

Fics. 12a-c. Globorotalia pusilla laevigata Bolli. Hypotype, from S.48, Gebel Owaina
section. P.45623

Bull. B.M.(N.H.) Geol. Suppt. 2 PLATE 17

PLATE 18
(All figures approximately x 76)
a, dorsal view ; b, side view ; c, ventral view

Fics. ta-c. Globorotalia uncinata uncinata Bolli. Hypotype, from S.34, Gebel
Owaina section. P.45636

Fics. 2a-c. Globorotalia tribulosa Loeblich & Tappan. Hypotype, from S.32, Gebel
Owaina section. P.45630

Fics. 3a-c. Globorotalia pseudobulloides (Plummer). Hypotype, from S.38, Gebel
Owaina section showing a slightly extraumbilical aperture. P.45621

Fics. 4a-c. Globorotalia quadrata White. Hypotype, from S.7, Gebel El-Kilabiya section,
showing a very slightly extraumbilical aperture. P.45627

Fics. 5a-c. Transitional stage between Globorotalia trinidadensis Bolliand Globorotalia
uncinata uncinata Bolli. P.45632

Fics. 6a-c. Globigerina arabica sp. nov. Holotype, from S.30, Gebel Owaina section.
P.45570.

Fics. 7a-c. Globorotalia trinidadensis Bolli. Hypotype, from S.7, Gebel El-Kilabiya
section. P.45631

PLATE 18

N
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nH
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=
S
Ss
=
RQ
ea

PLATE 19
(All figures approximately x 76)
a, dorsal view ; b, d, side views ; c, ventral view

Fics. ta-d. Globorotalia uncinata carinata subsp. nov. Holotype, from S.36, Gebel

Owaina section. P.45634
Fics. 2a-c. Globorotalia uncinata uncinata Bolli. Hypotype, from S.35, Gebel Owaina

section. P.45637
Fics. 3a-c. Globorotalia pusilla mediterranica subsp. nov. Holotype, from S.37, Gebel

Owaina section. P.45624

Fics. 4a-c. Globorotalia faragi sp. nov. Holotype, from $.34, Gebel Owaina section.
P.45608

Fics. 5a-c. Globorotalia acuta Toulmin. Hypotype, from S.40, Gebel Owaina section.
P.45591

Fics. 6a-c. Globorotalia velascoensis caucasica (Glaessner). Hypotype, from S.41,
Gebel Owaina section. P.45638

PLATE 19

Bull. B.M.(N.H.) Geol. Suppt. 2

PLATE 20
(All figures approximately x 76)
a, dorsal view ; b, d, side views ; c, ventral view

Fics. 1a-d. Globorotalia acuta Toulmin. Hypotype, from S.40, Gebel Owaina section.
P.45590

Fics. 2a-d. Globorotalia occlusa Loeblich & Tappan. Hypotype, from S.40, Gebel
Owaina section. P.45618

Fics. 3a-d. Globorotalia velascoensis velascoensis (Cushman). Hypotype, from S.41,
Gebel Owaina section. P.45640

Fics. 4a-d. Globorotalia velascoensis parva Rey. Hypotype, from S.41, Gebel Owaina
section. P.45639

Bull. B.M.(N.H.) Geol. Suppt. 2 PLATE 20

PLATE 21
(All figures approximately x 76)
a, dorsal view; b, side view ; c, ventral view

Fics. ta-c. Globorotalia apanthesma Loeblich & Tappan. Hypotype, from S.40, Gebel
Owaina section. P.45596

Fics. 2a-c. Globorotalia perclara Loeblich & Tappan. Hypotype, from S.35, Gebel
Owaina section. P.45620

Fic. 3. Globorotalia velascoensis velascoensis (Cushman). Ventral view of Hypotype,
from $.37, Gebel Owaina section, showing a distinctly protruding ventral side and a relatively
narrow umbilicus. P.45641

Fics. 4a-c. Globorotalia aequa Cushman & Renz. Hypotype from S.55, Gebel Owaina
section. P.45592

Fias. 5a-c. Globorotalia hispidicidaris Loeblich & Tappan. Hypotype, from $.55, Gebel
Owaina section. P.45610

Fics. 6a-c. Globorotalia esnaensis (Le Roy). Hypotype, from $.49, Gebel Owaina
section. P.45607

Bull. B.M.(N.H.) Geol. Suppt. 2 PLATE 21

PLATE 22
(All figures approximately x 76)
a, dorsal view ; b, d, side views ; c, ventral view

Fics. 1a-c. Globorotalia angulata angulata (White). Hypotype, from S.35, Gebel
Owaina section. P.45595

Fics. 2a-c. Globorotalia angulata abundocamerata Bolli. Hypotype, from S.39, Gebel
Owaina section. P.45594

Fics. 3a-c. Globorotalia cf. convexa Subbotina. Hypotype, from $.37, Gebel Owaina
section. P.45604

Fics. 4a-c. Globorotalia occlusa Loeblich & Tappan. Hypotype, from S.51, Gebel
Owaina section. P.45619

Figs. 5a-6d. Globorotalia bollii sp. nov. Figs. 5a—d, holotype and figs. 6a—d, paratype
from S.68, Gebel Owaina section. P.45599, P.45600

Bull. B.M.(N.H.) Geol. Suppt. 2 PLATE 22

TRUE NIE 7.5}
(All figures approximately x 76)
a, dorsal view ; b, d, side views ; c, ventral view

Fics. ta-c. Globorotalia loeblichi sp. nov. Holotype, from S.68, Gebel Owaina section.
P.45615

Fics. 2a-c. Globorotalia woodi sp. nov. Holotype from S.40, Gebel Owaina section.
P.45616

Fics. 3a-c. Globorotalia whitei Weiss. Hypotype, from S.55, Gebel Owaina section.
P.45642

Fics. 4a-c. Globorotalia africana sp. nov. Holotype, from S.50, Gebel Owaina section.
P.45593

Fics. 5a-c. Globorotalia wilcoxensis Cushman & Ponton. Holotype, from S.64, Gebel
Owaina section. P.45643

Fics. 6a-c. Globorotalia sibaiyaensis sp. nov. Holotype, from S.50, Gebel Owaina
section. P.45628

Fics. 7a-c. Globorotalia berggreni sp.nov. Holotype, from S.51, Gebel Owaina section.
P.45597

Fics. 8a-d. Globorotalia sp., from S.35, Gebel Owaina section. P.45644

Fics. ga-c. Globorotalia irrorata Loeblich & Tappan. Hypotype, from S.51, Gebel
Owaina section. P.45612

PLATE 23

2

Geol. Suppt.

)

H

N.

(

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M.

B

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