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2) SEP 1966

BULLETIN OF ae
AL WSS
THE BRITISH MUSEUM
(NATURAL HISTORY)

GEOLOGY
VOL. X
1964—1965

TRUSTEES OF
THE BRITISH MUSEUM (NATURAL HISTORY)
LONDON: 1966

DATES OF PUBLICATION OF THE PARTS

No.
No.
No.
No.
No.
No.
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No. ro.
No. 11.

10 July

2 December .
26 February
27 April

3 June

7 July.

12 July

15 December
24 November
3 December .
3, December .

PRINTED IN GREAT
BY ADLARD & SON
BARTHOLOMEW PRESS,

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1904
1964
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Not I
INO? 2
INO! 3
No. 4
No. 5
No. 6
No. 7
No. 8
No. 9
No. 10
No. Ir

CONTENTS

GEOLOGY VOLUME X

PAGE
Middle Jurassic Ostracoda from the Millepore Series, Yorkshire.
Ree BADE: I
Revision of British marine Cretaceous Ostracoda with notes on
additional forms. P. KAYE 35
Two heterosporous plants from the Upper Devonian of North
America. J. M. PETritr 81
Silurian Polyzoa from Benthall Edge, Shropshire. D. E. OWEN 93
Fossil Ginkoales from the Ticé Flora, Santa Cruz Province, Argentina.

S. ARCHANGELSKY 11g
The generic position of Osmundites dowkeri Carruthers. M. E. J.
CHANDLER 139
Fossil Mammals of Africa No. 18: East African Miocene and
Pleistocene Chalicotheres. P.M. BUTLER 163
Fossil Mammals of Africa No. 19: The Miocene Carnivora of East
Africa. R. J. G. SAVAGE 239
Dechenellid Trilobites from the British Middle Devonian. E. B.
SELWOOD 317
Cretaceous Ammonites and Nautiloids from Angola. M. K.
HowaARrRTH 335
The Fauna of the Portrane Limestone, III. D. Karjo & E.
KLAAMANN 413

Index to Volume X 435

“MIDDLE JURASSIC OSTRACODA
ROM THE MILLEPORE SERIES,
é, YORKSHIRE

R. H. BATE

ea BULLETIN: OF-

TISH MUSEUM (NATURAL HISTORY)
| <3 ie De Vol. to No. 1

Si LONDON: 10964.

MIDDLE JURASSIC OSTRACODA FROM THE
MEE PORE, SERIES, YORKSHIRE

Za \
JUL 1964
ee:

RAYMOND HOLMES BATE, Ph.D.

Pp. 1-33 ; 14 Plates; 1 Text-figure

BULLETIN OF
THE BRITISH MUSEUM (NATURAL HISTORY)
GEOLOGY | Vol. 10 No. 1
\ LONDON: 1964

THE BULLETIN OF THE BRITISH MUSEUM
(NATURAL HISTORY), <¢mnstituted im 1949, 1s
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.

This paper 1s Vol. 10, No. i of the Geological
(Palaeontological) series. The abbreviated titles of
periodicals cited follow those of the World List of
Scientific Perrodicals.

TRUSTEES OF
THE BRITISH MUSEUM (NATURAL HISTORY)

Issued July, 1964 Price Thirty-five Shillings

MILLEPORE SERIES, YORKSHIRE
By R. H. BATE

CONTENTS

I. INTRODUCTION AND ACKNOWLEDGEMENTS
II. SySTEMATIC DESCRIPTIONS

Order Podocopida Miiller
Suborder Platycopina Sars
Family Cytherellidae Sars
Genus Cytherelloidea Mexander :
Cytherelloidea catenulata (Jones & Shadoova
Suborder Podocopina Sars : : : : :
Superfamily Bairdiacea Sars
Family Bairdiidae Sars.
Genus Bairdia M‘Coy
Bardia hilda Jones
Superfamily Cypridacea Baird
Family Paracyprididae Sars
Genus Paracypris Sars
Parvacypris bajociana Bate
Superfamily Cytheracea Baird
Family Bythocytheridae Sars
Genus Monoceratina Roth 5
Monoceratina vulsa (Jones & Ghecbou)
Family Progonocytheridae Sylvester-Bradley ;
Subfamily Progonocytherinae Sylvester-Bradley
Genus Progonocythere Sylvester-Bradley .
Progonocythere cristata Bate
Genus Acanthocythere Sylvester-Bradley
Subgenus Protoacanthocythere Bate

Acanthocythere (Protoacanthooythere) Waucolaia Bate c

Genus Aulacocythere Bate :
Aulacocythere punctata Bate
Aulacocytheve reticulata Bate

Genus Fuhrbergiella Brand & Malz .

Subgenus Praefuhrbergiella Brand & Malz
Fuhrbergiella (Praefuhrbergiella) avens Bate
Fuhrbergiella (Praefuhrbergiella) minima sp. nov.

Genus Micropneumatocythere Bate
Micropneumatocythere convexa Bate
Micropneumatocythere globosa sp. nov.

Genus Pneumatocythere Bate .

Pneumatocythere bajociana Bate
Pneumatocythere cavinata sp. nov.
Subfamily Pleurocytherinae Mandelstam .

Genus Pleurocythere Triebel
Pleurocythere kivtonensis Bate
Pleurocythere nodosa Bate

Family Cytherideidae Sars
Subfamily Cytherideinae Sars

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MIDDLE JURASSIC OSTRACODA FROM THE

4 OSTRACODA FROM THE MILLEPORE SERIES, YORKSHIRE ©

f Page
Genus Dolocytherve Mertens _ _. a ae Eee : : 14
Dolocythere maculosa Bate. : : : é 14
Family Schulerideidae Mandelstam_. : : : : 9 15
Subfamily Schulerideinae Mandelstam : . : : 15
Genus Asciocythere Swain : : : : 6 : 15
Asciocytheve acuminata sp.nov. . ‘ : : 15
Asciocythere lacunosa Bate . : : : dnc lO
Genus Eocytheridea Bate 4 5 ; F : : 16
Eocytheridea ? acuta sp. nov.. ‘ 3 : ‘ 16
Eocytheridea ? astricta sp. nov. : : : 3 17
Eocytheridea cavinata sp. nov. : 5, : : 18
Eocytheridea elongata Bate . : 5 : : 19
Eocytheridea ? evugata sp. nov. : F j ; 19
Eocytheridea faveolata sp. nov. 5 : ‘ : 20
Eocytheridea lacunosa Bate . : : 6 : 21
Eocytheridea reticulata sp. nov. ‘ , PS : 21
Genus Praeschuleridea Bate. ; : 22
Pyaeschuleridea subtrigona (Jones & Shewbinea), : 22
Pyaeschuleridea subtrigona subtrigona (Jones &
Sherborn) : ; <n ae 22
Praeschuleridea Sa Acorn acne sud sp. Nov. é 23
Praeschuleridea ventriosa (Plumhoff) : b ; 24
Praeschulevidea ventriosa ventriosa (Plumhoff) . : 24
Family Cytheruridae Miiller : 6 : F : é 24
Genus Cytheropterina Mandelstam : : ; ; : 24
Cytheropterina plana sp. nov. : . : ; 24
Family Protocytheridae Ljubimova . : ‘ . 5 : 25
Subfamily Kirtonellinae Bate : : 2 ae , ; 25
Genus Kuirtonella Bate . 5 : ; : : F 25
Kirtonella plicata Bate : ‘ : ; 5 25
Kirtonella reticulata sp. nov. . : ‘ : : 25
Genus Ektyphocythere Bate. : 5 ; : 20
Ekty phocythere oes (Brand) ; : : : 26
Genus Southcavea nov. . : : : : : 27
Southcavea reticulata oo nov. c . . : Py
Southcavea bajociana (Bate) . ; ‘ , : 28
Southcavea grandis sp. nov. . ; : : : 29
Genus Systenocythere Bate : j : : 0 29
Systenocythere exilofasciata Bate ‘ : : 6 29
Systenocythevre ? sp. ; : : ; : i 30
Incertae Sedis_ . 0 4 ; ; 3 : : 30
III. REFERENCES : j ; : j : : : : : : 31
SLONOWSMS)

The ostracod fauna of the Middle Jurassic (Bajocian) Millepore Series of Yorkshire is described.
Twenty genera, thirty-eight species and three subspecies belonging to the order Podocopida
Miiller 1894 are recorded, of which one genus, fourteen species and one subspecies are new.
Six ostracods (incertae sedis) are listed under registration numbers to complete the fauna.

I INTRODUCTION AND ACKNOWLEDGEMENTS

THE present paper, in which the ostracod fauna of the Millepore Series is described,
is the third dealing with the Middle Jurassic Ostracoda of north-eastern England.

OSTRACODA FROM THE MILLEPORE SERIES, YORKSHIRE 5

The Millepore Series consist in the main of a thick, oolitic limestone, which
extends along the western outcrop of the Middle Jurassic as far north as Kirby
Knowle, and in the east, as far north as Robin Hood’s Bay. Southwards the
Millepore Series extends to the river Humber, to the south of which it becomes part
of the Lincolnshire Limestone.

In the neighbourhood of South Cave, the oolitic limestone is known locally as
the Cave Oolite, whilst to the north it is known as the Whitwell Oolite. Along the
coastal (eastern) outcrop, the limestone is referred to as the Millepore Oolite.
Although all three occur at the same stratigraphical horizon, nowhere are they
traceable one to the other. Above the Millepore Oolite, a marine sandstone/shale
horizon occurs, the Yons Nab Beds (see Bate 1959). In the west a flaggy oolitic
limestone (Upper Limestone of Hudleston 1874) overlies the Whitwell Oolite, from
which it is separated by a.bed of unconsolidated sand.

The Cave, Whitwell and Millepore Oolites, and the Upper Limestone and the Yons
Nab Beds are here considered under the single heading, the Millepore Series. The
term “ Series’ is retained to conform with the nomenclature in general use for the
remainder of the Yorkshire Middle Jurassic, although “‘ Formation ”’ would be the
more applicable.

A generalised table of the Middle Jurassic Beds of Yorkshire is given on p. 7.
A more detailed consideration of the stratigraphy is to be undertaken in a later
publication when it is hoped to discuss the suggestion of Kent (1955 : 208) that the
Millepore Series is equivalent to the Upper Lincolnshire Limestone (Hibaldstow
Oolite) of North Lincolnshire. An examination of the ostracods from the latter
horizon is in progress.

The Millepore Series has been sampled at the following localities, the numbers
corresponding with those indicated in Text-fig. 1 :—

Cave Oolite.

I. Eastfield Quarry, South Cave, map reference SE/913323.

Whitwell Oolite.
2. Westow Low Grange Quarry, map reference SE/766647.
3. Seamer Lime and Stone Co’s. Quarry, at junction of York—Malton road and
the Castle Howard station road, map reference SE/734672.
4. Stonecliff Wood, map reference SE/737675.
5. Quarry on the Bulmer—Welburn road, map reference SE/704678.

Upper Limestone.
2. Howl Beck, below Westow—Burythorpe road, map reference SE/766652.
3. Seamer Lime and Stone Co’s. Quarry, map reference SE/734672.
4. Stonecliff Wood, below gate to the entrance of the Crambeck road, map
reference SE/736675.

Millepore Oolite.
6. Yons Nab headland, Cayton Bay, map reference TA/084844.
7. Osgodby Nab headland, Cayton Bay, map reference TA/065855.
8. Cloughton Wyke, map reference TA/021958.

6 OSTRACODA FROM THE MILLEPORE SERIES, YORKSHIRE

NORTH
SEA

iy
Scarborough

Pickering
v

Malton
=

Market
Weightone

OM e2nard 8 miles
———SS

Kirton
Lindsey

Fic. 1 Outcrop of

Middle Jurassic Strata in N.E. England, with the localities [1-8] mentioned in
the text.

OSTRACODA FROM THE MILLEPORE SERIES, YORKSHIRE

Yons Nab Beds.

6. Yons Nab headland, Cayton Bay, map reference TA/084844.
8. Cloughton Wyke, map reference TA/o21958.

TABLE I
South West North West North East Stages
Cornbrash ? Cornbrash Callovian
Upper
Upper Deltaic Series | Upper Deltaic Series Bathonian
“ Estuarine ”
Grey Limestone Series | Grey Limestone Series
Middle Deltaic Series | Middle Deltaic Series
Series (Upper) (Upper)
Cave Upper Limestone Yons Nab Beds
Oolite Whitwell Oolite Millepore Oolite
Bajocian
Basement Beds Middle Deltaic Series | Middle Deltaic Series
(Lower) (Lower)
Hydraulic Limestone | Hydraulic Limestone/ Eller Beck Bed
Eller Beck Bed
Lower Deltaic Series Lower Deltaic Series
Lower “ Estuarine ”’
Series
Dogger Dogger
Lias Lias Lias Toarcian

TABLE 1. A generalized table of the Middle Jurassic Strata in Yorkshire.

8 OSTRACODA FROM THE MILLEPORE SERIES, YORKSHIRE

Map references refer to the one inch Ordnance Survey map of.Great Britain
(seventh series).

Muscle scar types A—D, referred to in the text, are those established in Bate (1963).

I would like to record my sincere thanks to Professors L. R. Moore (Sheffield
University) and P. C. Sylvester-Bradley (Leicester University) for the use of
departmental facilities during the research of which the present paper is a part ;
to Professor Sylvester-Bradley for much help and advice ; and to the Department
of Scientific and Industrial Research for a grant which made the work possible.

The loan of type or comparative material from the following is also gratefully
acknowledged : Dr. P. S. Ljubimova, V.N.I.G.R.I., Leningrad ; Drs. H. Malz, and
E. Triebel, Senckenberg Museum, Frankfurt ; Dr. B. Moos, Amt fiir Bodenforschung,
Hanover ; Dr. F. Plumhoff, Erd6l A.G., Wietze krs. Celle and Dr. F. Westphal,
University of Tiibingen.

All registered specimens mentioned in the text are in the collections of the
Department of Palaeontology, British Museum (Natural History).

II SYSTEMATIC DESCRIPTIONS
Order PODOCOPIDA Miller 1894
Suborder PLATYCOPINA Sars 1866
Family CYTHERELLIDAE Sars 1866
Genus CYTHERELLOIDEA Alexander 1929

Cytherelloidea catenulata (Jones & Sherborn)

1888 Cytherella catenulata Jones & Sherborn : 274, pl. 5, fig. 6a—c.
1948 ? Cytherelloidea catenulata (Jones & Sherborn) Sylvester-Bradley : 200, pl. 14, fig. 11,
text-fig. 7.
1963 Cytherelloidea catenulata (Jones & Sherborn) ; Bate : 184, pl. I, figs. 3-6.
REMARKS. Only two occurrences of this species have so far been noted within
the Millepore Series, namely, single specimen in the Cave Oolite, Eastfield Quarry,
and two specimens in the Whitwell Oolite, Seamer Lime and Stone Co’s. Quarry.

Suborder PODOCOPINA Sars 1866
Superfamily BAIRDIACEA Sars 1888
Family BAIRDIIDAE Sars 1888
Genus BAIRDIA M‘Coy 1844

Bairdia hilda Jones

1884 Bairdia hilda Jones : 771, pl. 34, fig. 20.

1888 Bairdia fullonica Jones & Sherborn : 253, pl. 5, fig. 4a-c.

1948 Bairdia cf. hilda Jones ; Sylvester-Bradley : 199, text-fig. 5.
1963 Bardia hilda Jones ; Bate : 188, pl. 2, figs. 9-12, pl. 3, figs. 1-4.

REMARKS. Two valves represent this species at a single horizon within the Cave
Oolite, Eastfield Quarry.

OSTRACODA FROM THE MILLEPORE SERIES, YORKSHIRE 9

Superfamily CYPRIDACEA Baird 1845
Family PARACYPRIDIDAE Sars 1923
Genus PARACYPRIS Sars 1866

Paracypris bajociana Bate

1963 Pavacypris sp. D Oertli ; Plumhoff : 18, pl. 1, figs. 9-11.
1963 Pavacypris bajociana Bate : 186, pl. 2, figs 1-8.
1963a Pavacypris bajociana Bate : 20.

Remarks. Although never abundant, the species occurs persistently throughout
the Cave, Whitwell and Millepore Oolites and within the Upper Limestone and Yons
Nab Beds.

Plumhoff (1963 : 18, pl. 1, figs. g-11) figures a species of Paracypris which he
considers to be conspecific with Paracypris sp. D. Oertli (1959 : 20, pl. 2, figs. 43, 44).
There are, however, differences in the concavity of the ventral margin, in the
narrowness of the anterior part of the carapace, and in the length of the postero-
dorsal slope of the latter, which distinguish it from Plumhoff’s specimens.
Accordingly Oertli’s species is not included in the synonymy.

Superfamily CYTHERACEA Baird 1850
Family BYTHOCYTHERIDAE Sars 1926
Genus MONOCERATINA Roth 1928

Monoceratina vulsa (Jones & Sherborn)
1888 Cytheridea vulsa Jones & Sherborn : 263, pl. 2, fig. 4a—b.
1938 Monoceratina vulsa (Jones & Sherborn) Triebel & Bartenstein : 516, pl. 3, figs. 17, 18.
1960 Monoceratina cf. vulsa (Jones & Sherborn) ; Lutze : 433, pl. 37, fig. 5a—b.
?1963 Monoceratina sp. juv. aff. vulsa (Jones & Sherborn) ; Plumhoff : 48, pl. 11, figs. 167, 168.
1963 Monocevatina vulsa (Jones & Sherborn) ; Bate : 189, pl. 3, figs. 5-12.
1963a@ Monoceratina vulsa (Jones & Sherborn) ; Bate : 26, pl. 1, fig. 6.

Remarks. Not common, but occurring sporadically throughout the Millepore
Series, being found in the Cave, Whitwell and Millepore Oolites and also in the
Upper Limestone. In Bate (1963 & 1963a) Bythocythere aliena Ljubimova (1955 :
34, pl. 2, fig. 3 a-b) was placed tentatively in synonymy with M. vulsa. Dr.
Ljubimova has since sent me specimens of her species for comparison and it is quite
clear that B. aliena should be taken out of synonymy.

Family PROGONOCYTHERIDAE Sylvester-Bradley 1948
Subfamily PROGONOCYTHERINAE Sylvester-Bradley 1948
Genus PROGONOCYTHERE Sylvester-Bradley 1948
Progonocythere cristata Bate

1963 Pyvogonocythere cristata Bate : 191, pl. 4, figs. 5-15, pl. 5, figs. 1-6.
1963a Pyrogonocythere cristata Bate ; Bate : 27.

REMARKS. The species is poorly represented in the oolitic facies of the Millepore
Series, where only a few specimens have been found at the top of the Millepore and

10 OSTRACODA FROM THE MILLEPORE SERIES, YORKSHIRE

Whitwell Oolites of Yons Nab headland and the Seamer Lime and Stone Co’s.
Quarry, respectively. A single specimen has also been found in the Upper Limestone
at the latter locality. Within the shale facies of the Yons Nab Beds, however, as
exposed at Yons Nab, P. cristata becomes a common ostracod. In Lincolnshire,
the species is present in the oolitic facies of the Lincolnshire Limestone (Bate 1963),
but is more abundant within the Kirton Shale facies. It would appear, therefore,
that, although not restricted by the facies present, this ostracod favours an
environment having a muddy substratum.

Genus ACANTHOCYTHERE (Sylvester-Bradley 1956) emend Bate 1963
Subgenus PROTOACANTHOCYTHERE Bate 1963

Acanthocythere (Protoacanthocythere) faveolata Bate
1963 Acanthocythere (P.) faveolata Bate : 195, pl. 7, figs. 5-13, pl. 8, figs. 1-5.
1963a Acanthocythere (P.) faveolata Bate ; Bate : 28.

REMARKS. This species has so far been found only at two horizons within the
Cave Oolite, as exposed in the Eastfield Quarry. In each case a single valve is all
that represents the species. Fuhrbergiella (Praefuhrbergiella)? favosa Plumhoff
(1963 : 206, pl. 3, figs. 52-55), which is very close to the present species, differs in the
possession of a prominent posteroventral extension of the carapace, in the absence
of spines, and in being larger.

Genus AULACOCYTHERE Bate 1963

Aulacocythere punctata Bate

1963 Aulacocythere punctata Bate : 199, pl. 9, figs. 4-9, II-12, 14-15.
1963a Aulacocythere punctata Bate ; Bate : 28.

REMARKS. A. punctata is a rare member of the ostracod fauna within the
Millepore Series. A single specimen has been found in the Millepore Oolite,
Osgodby Nab, and isolated carapaces and valves occur sporadically throughout the
Whitwell Oolite at the Seamer Lime & Stone Co’s. Quarry. It is, however, nearly
always present though rare in samples of the Cave Oolite, Eastfield Quarry.

Aulacocythere reticulata Bate
1963 Aulacocythere reticulata Bate : 200, pl. 9, figs. 10, 13, 16-25, pl. Io, fig. 1.
REMARKS. A single carapace was found in the Whitwell Oolite, Seamer Lime and
Stone Co’s. Quarry.

Genus FUHRBERGIELLA Brand & Malz 1962
Subgenus PRAEFUHRBERGIELLA Brand & Malz

Fuhrbergiella (Praefuhrbergiella) arens Bate
1963 Fuhrbergiella (P.) avens Bate : 197, pl. 8, figs. 6-15, pl. 9, figs. I-3.
REMARKS. This species has so far been found only in the Cave Oolite, Eastfield
Quarry, where it is more common towards the base of the limestone.

OSTRACODA FROM THE MILLEPORE SERIES, YORKSHIRE II

Fuhrbergiella (Praefuhrbergiella) minima sp. nov.
(Pl. 1, figs. 1-8)

Diacnosis. Praefuhrbergiella with small, subquadrate carapace. Shell reticulate
with oblique transverse ridges.

Horotyre. Io.1021, Millepore Oolite, Cloughton.

PARATYPES. I[o0.1022—23 and Io.1035, horizon and locality as above and from
the Whitwell Oolite, Seamer Lime and Stone Co’s. Quarry.

DESCRIPTION. Carapace subquadrate with the greatest length passing through
midpoint, greatest height in the anterior third, greatest width in the posterior third.
Shell dimorphic, the more elongate specimens being considered to be the males.
Dorsal margin straight, overreached posterodorsally by the strongly convex dorso-
lateral border. Ventral margin incurved anteromedially. Ventral surface overhung
by the convex ventrolateral border. Anterior broadly rounded ; posterior broadly
triangular in the female dimorph, more acute in the male, where the posterodorsal
slope is strongly concave. Anterior and posterior with flattened marginal borders,
the anterior border being characteristically directed obliquely back towards the
anterior cardinal angle. Cardinal angles prominent. Shell surface reticulate, with
a tendency for the reticulation to produce low ridges trending obliquely anteroven-
trally from the dorsal margin. A rounded eye swelling is situated at the anterior
cardinal angle. Ventral surface with 3-4 low, parallel ridges. Left valve slightly
larger than the right, which it overlaps along the ventral margin and to a lesser
degree at the cardinal angles. Internal details unknown.

Dimensions

HoLotypPe. lo.1021, female carapace (PI. 1, figs. 1-4), length 0-50 mm. ; height
0-30 mm. ; width 0:27 mm.

PARATYPES. [0.1035, male carapace (PI. 1, figs. 5-8), length 0-48 mm. ; height
0:27 mm. ; width 0:23 mm. lIo.1022, male carapace, length 0-56 mm. ; height

0-30 mm. ; width 0-24 mm. Io.1023, male carapace, length 0-57 mm. ; height
0:26 mm. ; width 0:22 mm.

REMARKS. A rare species, found so far only in the Millepore and Whitwell
Oolites.

Genus MICROPNEUMATOCYTHERE Bate 1963

Micropneumatocythere convexa Bate
?1960 Ostracod No. 3 Lutze : 434, pl. 38, fig. 1a, b.
1963a Micropneumatocythere convexa Bate : 29, pl. 2, figs. 12~13, pl. 3, figs. 1-15.

REMARKS. Although this species occurs in the Cave, Whitwell and Millepore
Oolites, it is never common.

12 OSTRACODA FROM THE MILLEPORE SERIES, YORKSHIRE

Micropneumatocythere globosa sp. nov.
(Pl. 1, figs. 9-20)

DiaGNosis. Micropneumatocythere with swollen, rather rotund carapace. Shell
surface very finely punctate. Normal pore canal openings large.

HorotypPe. lIo.1o10, Cave Oolite ; Eastfield Quarry, South Cave.

PARATYPES. Io.r01I-17, lo.101g (six carapaces), Io.1020 (four carapaces),
horizon and locality as above; from the Whitwell Oolite, Seamer Lime and Stone Co’s.
Quarry and Stonecliff Wood ; Yons Nab Beds and Millepore Oolite, Yons Nab ;
and from the Millepore Oolite, Cloughton.

DESCRIPTION. Carapace ovoid, strongly convex in dorsal view. Ventrolateral
border overhanging the ventral surface in lateral view. Species dimorphic, the
presumed males being more elongate. Dorsal margin broadly convex ; ventral
margin anteromedially incurved. Anterior broadly rounded ; posterior triangular
with a slightly concave posterodorsal slope, particularly in the right valve, and a
convex posteroventral slope. Greatest length passes through midpoint ; greatest
height and width just behind midpoint. Shell surface smooth, very finely. punctate
in well preserved specimens. Ventral surface weakly striated. Normal pore canal
openings large, widely scattered over the surface of the carapace. Left valve larger
than the right, which it slightly overlaps midventrally. Along the dorsal margin,
posterodorsal and anterodorsal slopes the left valve prominently overreaches the
right. Hinge antimerodont ; left valve with a broad, shelf-like accommodation
groove and a rather coarsely dentate median element. Hinge not clearly seen in the
right valve, but there are approximately six posterior teeth. Inner margin and
line of concrescence coincide ; radial pore canals short, straight and widely spaced,
exact number not observed. Duplicature of moderate width. Muscle scars not
observed.

Dimensions.

HoLotyPe. lo.1010, female carapace (PI. 1, figs. 9, 10, 15 & 16), length 0-42 mm. ;
height 0-29 mm. ; width 0:28 mm.

PARATYPES. Io.1011, male carapace (Pl. 1, figs. 17-20), length 0-49 mm. ;
height 0-30 mm. ; width 0-30 mm. Io.1012, female left valve (Pl. 1, figs. 11, 12),
length 0-37 mm. ; height 0-25 mm. Io.1013, male left valve (PI. 1, fig. 14), length
0-53 mm. ; height 0-32 mm. Io.1014, female right valve (Pl. 1, fig. 13), length
0-40 mm. ; height 0-25 mm. lIo.1015, female carapace, length 0-39 mm. ; height
0-26 mm. ; width 0-26 mm. _ lIo.1016, female right valve, length o-40 mm. ;
height 0-26 mm. lo.1017, female carapace, length 0-47 mm. ; height 0:29 mm. ;
width 0-30 mm.

REMARKS. Mucropneumatocythere globosa occurs throughout the Millepore Series,
being a common member of the ostracod fauna at this horizon, particularly within
the limestone facies. The species is either absent or not very common within the
shale facies of the Yons Nab Beds.

OSTRACODA FROM THE MILLEPORE SERIES, YORKSHIRE 13

Genus PNREUMATOCYTHERE Bate 1963
Pneumatocythere bajociana Bate

1963 Pneumatocythere bajociana Bate : 193, pl. 5, figs. 7-10, pl. 6, figs. 1-10, pl. 7, figs. 1-4.
1963a Pneumatocythere bajociana Bate ; Bate : 30.

REMARKS. This is a common ostracod within the shale and sandy limestone
facies of the Yons Nab Beds (the type horizon) and in the limestone facies of the
Millepore Oolite at Yons Nab and Osgodby Nab. It is virtually unrepresented
within the Whitwell Oolite and Upper Limestone, and has not been found at all in
the Cave Oolite.

Pneumatocythere carinata sp. nov.
(Pl. 2, figs. 1-9)

DiacGnosis. Pneumatocythere with strongly ornamented carapace : ornamenta-
tion consisting of prominent transverse ridges in the dorso-median part, breaking
into a strong reticulation at about valve centre.

HorotypPe. Io.1024, Upper Limestone, Stonecliff Wood.

PARATYPES. I[0.1025—34, Whitwell Oolite, Bulmer, and Seamer Lime and Stone
Co’s. Quarry ; Cave Oolite, Eastfield Quarry ; and Millepore Oolite, Yons Nab.

DESCRIPTION. Cavapace ovoid, strongly convex in dorsal view. Ventrolateral
border convex, overhanging the ventral surface, especially so just behind valve
middle. Dimorphism was suggested by a single, more elongate specimen, probably
a male, but unfortunately lost. All the remaining specimens appear to be females.
Greatest length through midpoint ; greatest height and width, median. Shell
surface strongly ornamented with transverse ridges which radiate outwards from the
dorsal margin and which, at about valve centre, break up into a reticulate ornamenta-
tion. An oblique, rather deep groove is situated below the anterior cardinal angle.
The ventral and ventrolateral surfaces combined possess 5—6 longitudinal ridges per
valve. Left valve larger than the right, which it overlaps along the ventral margin,
and overreaches along the dorsal and anterior margins. Dorsal margin slightly
convex, with broadly rounded cardinal angles. Anterior and posterior rounded.
Ventral margin incurved just anterior of valve middle. A distinct groove extends
around the anterior margin. ight valve closely similar in outline to the left. The
dorsal margin is, however, slightly less convex, and the anterodorsal slope, convex in
the left valve, is here slightly concave ; posterodorsal slope concave in both valves,
but more so in the right. Hinge antimerodont, only seen in the left valve : terminal
sockets coarsely loculate, median bar strongly dentate, accommodation groove
poorly developed. Inner margin and line of concrescence coincide. Radial pore
canals short, straight and few in number, although the exact number has not been
ascertained. Duplicature of moderate width. Muscle scars (Type A) consist of a
vertical row of four oval adductor scars, rounded anterodorsal antennal scar, and a
longitudinally elongate, anteroventral mandibular scar.

14 OSTRACODA FROM THE MILLEPORE SERIES, YORKSHIRE

Dimensions

HototypPe. Io.1024, female? carapace (Pl. 2, figs. 1-4), length 0-68 mm.
height 0-47 mm. ; width 0:52 mm.

PARATYPES. Io.1025, female? carapace, length 0-65 mm. ; height 0-44 mm. ;
width 0-48 mm. Io.1026, female? carapace, length 0-65 mm. ; height 0-40 mm. ;
width 0-48 mm. Io.1027, female? carapace, length 0-70 mm. ; height 0-45 mm. ;
width 0-49 mm. Io.1028, female? left valve (PI. 2, fig. 8), length 0-65 mm. ; height
0-46 mm. Io.1029, female? left valve (Pl. 2, figs. 5, 6), length 0-60 mm. ; height
0-42 mm. Io.1030, female? left valve (Pl. 2, figs. 7, 9), length 0-66 mm. ; height
0-46 mm.

REMARKS. P. cayinata is a rare member of the ostracod fauna, although it occurs
widely throughout the Millepore Series. It is not, however, found in the Yons Nab
Beds. Similar in appearance to P. bajociana (Bate 1963), it can be distinguished by
the much more strongly convex dorsal margin and stronger ornamentation.

Subfamily PLEUROCYTHERINAE Mandelstam 1960
Genus PLEUROCYTHERE Triebel 1951

Pleurocythere kirtonensis Bate

1963 Pleurocythere kivtonensis Bate : 203, pl. ro, figs. 14-18, pl. 11, figs. 1-5.
1963a Pleurocythere kivtonensis Bate ; Bate : 31.

REMARKS. Two broken carapaces from the Whitwell Oolite, Seamer Lime and
Stone Co’s. Quarry.

Pleurocythere nodosa Bate

1963 Pleuvocythere nodosa Bate : 204, pl. 11, figs. 6-21.

RemARKS. A right valve and a complete carapace found (at different horizons)
within the Cave Oolite, Eastfield Quarry.

Family CYTHERIDEIDAE Sars 1925
Subfamily CYTHERIDEINAE Sars 1925
Genus DOLOCYTHERE Mertens 1956

Dolocythere maculosa Bate
1941 Leptocythere ? sp. Triebel : pl. 7, figs. 71-72.
1949 Ostracod 99 Brand : 337, pl. to (fauna 1), fig. 5, pl. 14.
1962 Lophodentina ? sp. 99 Brand ; Brand & Fahrion : 129, 136, pl. 17 (fauna 9), fig. 6,
pl. 20, fig. 25.
1963 Dolocythere maculosa Bate : 205, pl. 12, figs. I-11.
1963a Dolocythere maculosa Bate ; Bate : 31.

REMARKS. Although never common, D. maculosa is generally represented in the
faunas of the Cave, Whitwell and Millepore Oolites, and to a lesser degree in the upper
Limestone and Yons Nab Beds.

OSTRACODA FROM THE MILLEPORE SERIES, YORKSHIRE 15

Family SGHULERIDEIDAE Mandelstam 1959
Subfamily SCHULERIDEINAE Mandelstam 1959
Genus ASCIOCY THERE Swain 1952

REMARKS. Asciocythere was erected by Swain (1952: 75) with Bythocypris
votundus Vanderpool (1928: 102, pl. 13, figs. 5, 6) as the type species. In the
description of the genus Swain states that the median hinge element of the left valve
is either a smooth or a denticulate bar. The species placed here in the genus are
characterised by possessing a strongly dentate median bar in that valve.

Asciocythere acuminata sp. nov.
(Pl. 2, figs. 10-12, Pl. 3, figs. 1-10)

Diacnosis. Asciocythere, oval in outline, tapering anteriorly and posteriorly ;
shell surface finely punctate ; greatest height median or just behind midpoint.

Hoxrotyre. l[o.1072, Cave Oolite, Eastfield Quarry.

PaRATYPES. Io.1073-76, horizon and locality as above, and from the Upper
Limestone, Stonecliff Wood ; and the Basement Beds, below the Cave Oolite,
Eastfield Quarry.

DESCRIPTION. Carapace oval in outline, tapering anteriorly and posteriorly, the
greatest height at or just behind middle. Greatest length passes through midpoint ;
greatest width in the posterior half. Shell surface finely punctate. Left valve
larger than the right, which it overlaps along the ventral margin and along the
posteroventral and posterodorsal slopes. Around the anterior and posterior margins
and along the dorsal margin the left valve overreaches the right. Dorsal margin
arched, without cardinal angles ; ventral margin strongly convex, incurved antero-
medially. Anterior rounded ; extreme posterior pointed or very narrowly rounded.
Right valve more elongate in outline than the left. Dorsal margin convex with
distinct cardinal angles, the anterodorsal slope being long and slightly convex.
Anterior rounded ; posterior acuminate with a concave posterodorsal slope and a
convex posteroventral slope. Ventral margin with the incurvature extending from
valve middle into the posterior half. Hinge antimerodont, only seen in the right
valve : approximately 5 posterior teeth, anterior teeth not preserved in this material.
Median groove broad, strongly loculate, overhung by the convex dorsal margin of the
valve. Inner margin and line of concrescence appear to coincide ; anterior radial
pore canals few in number and slightly curved, exact number not seen ; posterior
canals short and straight, approximately 4 in number. Muscle scars of type C :
adductor scars in a crescentic row with the anteromedian antennal scar kidney

shaped.

Dimensions

Hoxotyre. Io.1072, carapace (Pl. 2, figs. 10-12, Pl. 3 fig. 1), length 0-60 mm. ;
height 0-37 mm.; width 0-32 mm.

16 OSTRACODA FROM THE MILLEPORE SERIES, YORKSHIRE

PARATYPES. Io0.1073, carapace (Pl. 3, figs. 4, 5, 9 & 10), length 0-59 mm. ;
height 0-36 mm. ; width 0-29 mm. lIo.1074, carapace (Pl. 3, figs. 6, 7), length
0-53. mm. ; height 0-31 mm. ; widtho-23 mm. I[o.1075, right valve (PI. 3, figs. 2, 3),
length 0-56 mm. ; height 0-30 mm.

REMARKS. Only 5 specimens of this species are known so far, and these are placed
in Asciocythere on account of shape, muscle scars, radial pore canals and hinge
structure. The acuminate outline of this species distinguishes it from the others
placed in the genus.

Asciocythere lacunosa Bate

1963a Asciocythere lacunosa Bate: 34, pl. 6, figs. 3-9, pl. 7, figs. 1-6.
REMARKS. Several specimens of this species have been found in the Cave Oolite,
Eastfield Quarry.

Genus EOCYTHERIDEA Bate 1963

Eocytheridea? acuta sp. nov.
(Pl. 3, figs. 11—14)

DiaGnosis. Eocytheridea? with elongate carapace, tapering anteriorly ; drawn
out, acuminate, posteriorly.

HorotypPe. Io.1036, limestone band (basal Upper Limestone), interbedded with
yellow sand, overlying the Whitwell Oolite, Stonecliff Wood.

PARATYPES. [o.1037—39, horizon and locality as above, from the Yons Nab Beds,
Cayton Bay ; and from the top of the Millepore Oolite, Osgodby Nab.

DEscRIPTION. Carapace elongate, tapering strongly to the anterior and posterior.
Greatest length below midpoint ; greatest height equally at the anterior cardinal
angle and at valve middle; greatest width situated just behind valve middle. Shell
surface finely punctate where preservation permits, otherwise appears to be smooth.
Normal pore canal openings prominent, widely scattered over the carapace. Left
valve much larger than the right, which it overlaps along the ventral margin, parti-
cularly midventrally. The left valve also strongly overlaps the right in the region
of the cardinal angles. Dorsal margin straight, dorsolateral margin medially
incurved, cardinal angles broadly convex ; amnterodorsal slope long, convex ;
posterodorsal slope steeply angled, almost straight, very slightly concave. Anterior
rounded ; posterior narrowly rounded, tapering. Ventrolateral margin medially
convex, the convexity being represented also midventrally. Antero- and postero-
ventral slopes convex. Right valve similar in outline, differing in having a slightly
convex dorso-lateral margin and a much more strongly acuminate posterior;
posterodorsal slope long, strongly concave, posterodorsal slope convex. Ventral
margin medially convex, incurved antero- and postero-ventrally. Hinge, as seen
through the translucent shell, merodont, with dentate/loculate terminal elements ;
the median bar of the left valve may be denticulate but this cannot satisfactorily be
ascertained. Other internal details not seen.

OSTRACODA FROM THE MILLEPORE SERIES, YORKSHIRE 17

Dimensions

HototyrPeE. Io0.1036, carapace (PI. 3, figs. 11-14), length 0-93 mm. ; height
0-44 mm. ; width 0-43 mm.

PARATYPES. Io0.1037, carapace, length 0-83 mm. ; height 0-42 mm. ; width
o-40mm. Io.1038, carapace, length 0-88 mm. ; height 0-41 mm. ; width 0-43 mm.

REMARKS. The lack of knowledge concerning the internal details of this species
prevent its definite placing in Eocytheridea. External characteristics of shape and
valvular relationship suggest that it may, however, belong here. E.? acuta is a rare
ostracod found only within the Yons Nab Beds, at the top of the Millepore Oolite and
at the base of the Upper Limestone. In the general outline of the carapace, parti-
cularly the strong posterior taper, this ostracod can easily be distinguished from the
other species of the genus.

Eocytheridea? astricta sp. nov.
(Pl. 4, figs. 1-5)

Diacnosis. LEocytheridea ? with oval, elongate carapace, tapering to the anterior
and posterior with the greatest height at or just behind valve middle.

HototypPe. Io.1040, basal Upper Limestone, Stonecliff Wood.

PARATYPES. lo.1041-47, horizon and locality as above, from the top of the
Whitwell Oolite, Westow ; Yons Nab Beds and Millepore Oolite, Cayton Bay ;
and from the Basement Beds below the Cave Oolite, Eastfield Quarry.

DESCRIPTION. Cavapace elongate, rather narrow in side view with the greatest
height varying from median to just behind valve middle. Greatest length through
midpoint, greatest width in posterior third. Shell surface smooth. Left valve
larger than the right, which it overlaps strongly along the ventral margin and in
the region of the anterior and posterior cardinal angles. Dorsal margin straight,
overreached by the convex or almost straight dorsolateral margin. Anterior
cardinal angle very broad, passing smoothly into the convex anterodorsal slope.
Posterior cardinal angle distinct. Anterior evenly rounded ; posterior truncated,
with concave posterodorsal slope and broadly convex posteroventral slope. Ventral
margin convex, incurved anteromedially. Right valve elongate-oval, dorsolateral
margin convex ; anterior and posterior rounded, ventral margin anteromedially
incurved. Hinge antimerodont, with coarsely dentate/loculate terminal elements
and a coarsely dentate/loculate median element. Accommodation groove in the
left valve elongate, not well developed. Muscle scars, type C : the anteromedian
antennal scar, in a juvenile specimen, equal in size to two adductor scars. A small
scar is situated in front of the antennal scar. Mandibular scar, small. Duplicature,
as seen through the carapace, appears to be rather narrow ; radial pore canals
not clearly seen.

Dimensions

HoLotyPe. Io.1040, carapace (Pl. 4, figs. 1-4), length 0-98 mm.; height 0-05
mm.; width 0-49 mm.

18 OSTRACODA FROM THE MILLEPORE SERIES, YORKSHIRE

PaRATYPES. Io.1041, carapace, length 0-80 mm.; height 0-40 mm.; width
0-40 mm. Io.1042, carapace, length 0-79 mm.; height 0-41 mm.; width 0-41 mm.
Io.1044, juvenile carapace (PI. 4, fig. 5), length 0-67 mm.; height 0-31 mm.; width
0:-27mm. Io.1045, carapace, length 0-76 mm.; height 0-39 mm.; width 0-37 mm.

REMARKS. This species has been placed tentatively in Eocytheridea, although
it differs from all the others in the possession of an antimerodont hinge. It is not
a particularly common ostracod, although it is numerous in the sandy limestone
at the top of the Yons Nab Beds.

Eocytheridea carinata sp. nov.
(Pl. 4, figs. 6-11, Pl. 5, figs. 1-8)

Dracnosis. LEocytheridea, carapace with well developed carinae arranged in the
shape of an inverted V.

Horotype. lo.1048, Whitwell Oolite, Bulmer.

PaRATYPES. Io.1049-58, horizon and locality as above, from the Cave Oolite,
Eastfield Quarry ; Whitwell Oolite, Stonecliff Wood ; Millepore Oolite, Cloughton ;
and from the Yons Nab Beds, Cayton Bay.

DESCRIPTION. Cavapace subquadrate in young instars and adult female dimorphs,
elongate in the males. Greatest length through midpoint ; greatest height in the
anterior third, at the anterior cardinal angle ; greatest width in the posterior third.
Shell surface strongly ornamented with prominent carinae arranged in an inverted
V, the apex of which reaches the dorsolateral margin just behind valve middle.
The outermost V-ridge forms the boundary of a central convex area which, in
dorsal view, stands out from the remainder of the valve. In young instars there
are 3-4 carinae present, whilst in adult specimens the number increases to as many
as g, the increase being largely in the ventrolateral region. Ventral surface orna-
mented with 3-4 faint, longitudinal carinae. Anterior cardinal angle swollen,
particularly noticeable in the left valve, and may represent an eye swelling. Left
valve larger than the right, which it overlaps evenly along the ventral margin except
for the anteroventral sector, where the overlap becomes less and finally non-existent.
The left valve also overlaps the right in the region of the cardinal angles and strongly
overreaches the right along the entire dorsal margin, in which region a dorsal keel
is developed. Dorsal edge of valve, in side view, medially concave, cardinal angles
broadly rounded ; anterior uniformly rounded ; posterior narrowly rounded.
Ventral margin convex, incurved anteromedially. Ventrolateral margin broadly
convex, slightly overhanging the ventral surface in side view. Right valve smaller
in size, without the dorsal keel, otherwise similar in outline to the left valve. Hinge
hemimerodont : terminal elements rather coarsely dentate/loculate. Accommoda-
tion groove poorly developed. Inner margin and line of concrescence coincide.
Anterior vadial pore canals few in number, widely spaced and slightly curved,
exact number not seen. Muscle scars, type C: slightly curved row of 4 oval
adductor scars with an irregularly rounded, anteromedian antennal scar and a
rounded anteroventral mandibular scar.

OSTRACODA FROM THE MILLEPORE SERIES, YORKSHIRE ae)

Dimensions

Horotyre. Io.1048, female carapace (Pl. 5, figs. 1-4), length 0-65 mm.; height
0-43 mm.; width 0-43 mm.

PARATYPES. Io.1049, female carapace, length 0-65 mm.; height o-40 mm.;
width 0:38 mm. Io.1050, male right valve (Pl. 4, fig. 11), length 0-69 mm.; height
0:34mm. Io.1051, female left valve (Pl. 4, fig. 6), length 0-64 mm.; height 0-38 mm.
Io.1052, juvenile carapace (Pl. 4, figs. 7-10), length 0-47 mm.; height 0-32 mm.;
width 0-30 mm. Io.1054, male carapace (PI. 5, figs. 5-8), length 0-68 mm.; height
0:38 mm.; width 0:38 mm. Io.1055, female left valve, length 0-62 mm.; height
0-41 mm.

REMARKS. Eocytheridea carinata has been found throughout the Millepore
Series, with the exception of the Upper Limestone, and is one of the more commonly
occurring members of the ostracod fauna, being readily distinguished from the other
species of the genus by its characteristic ornamentation.

Eocytheridea elongata Bate
1963a Eocytheridea elongata Bate: 35, pl. 7, figs. 7-12, pl. 8, figs. 1-5.
ReMARKS. Very rare. Represented by a single right valve within the Whitwell
Oolite, Seamer Lime and Stone Co’s. Quarry, and by several poorly preserved
valves, possibly of this species, found in the Cave Oolite, Eastfield Quarry.

Eocytheridea? erugata sp. nov.
(PI. 5, figs. 9-12, Pl. 6, figs. 1-3)
Diacnosis. LEocytheridea ? with elongate carapace, posteriorly acuminate ;
shell surface smooth ; greatest height in anterior third.

Hototyre. Io.1059, base of Yons Nab Beds (bed 2, Bate 1959 : 159), Cayton
Bay.

PARATYPES. lo.1060—64, from the Millepore Oolite, Osgodby Nab and Cloughton;
Whitwell Oolite, Seamer Lime and Stone Co’s. Quarry ; Upper Limestone, Stonecliff
Wood ; and the Basement Beds below Cave Oolite, Eastfield Quarry.

DESCRIPTION. Carapace elongate, tapering posteriorly. Greatest length slightly
below midpoint ; greatest height in the anterior third ; greatest width in the
posterior third. Shell surface smooth. Left valve larger than the right which it
overlaps along the ventral margin, along the anterodorsal and posterodorsal slopes
and around the posterior margin. Dorsal margin slightly concave medially, sloping
to the posterior ; cardinal angles rounded. Anterior broadly rounded ; posterior
narrowly rounded. Ventral margin medially incurved. Right valve similar in
outline to the left, differing in possessing a convex dorsal margin. Hinge merodont,
but not clearly seen. Muscle scars, type ““C”’: a subvertical row of 4 adductor
scars with an anteromedian, crescentic, antennal scar, which in one instance appears
to be produced by the fusion of two small scars. Rounded mandibular scar antero-
ventral in position. Inner margin and line of concrescence, as seen from the exterior,
appear to coincide. Radial pore canals straight, widely spaced, 6-8 anteriorly.

20 OSTRACODA FROM THE MILLEPORE SERIES, YORKSHIRE

Dimensions

HorotypPe. lIo.1059, carapace (Pl. 5, figs. 9-11), length 0-67 mm.; height
0-33 mm.; width 0-29 mm.

PARATYPE. Io.1060, juvenile carapace (Pl. 5, fig. 12, Pl. 6, figs. 1-3), length
0-51 mm.; height 0-25 mm.; width 0-20 mm.

REMARKS. In outline, this species is close to Dolocytheridea bosquetiana (Jones &
Hinde 1890 : 4, pl. 2, fig. 65, pl. 4, fig. 3) and the male dimorph of Dolocytheridea
intermedia Oertli (1958 : 1505, pl. 3, figs. 68, 73, 74, pl. 4, figs. 75, 76, 80). There
are, however, slight differences in outline, such as the possession of a narrower
anterior margin and a slight concavity of the posterodorsal slope which distinguish
E. ? erugata from the above mentioned ostracods. EE. ? astricta tends to be more
oval in outline than the present species and, like E. ? acuta, has a greater postero-
dorsal overlap of the right valve by the left and a distinct anterior taper. EF. ?
erugata is a rare species, occurring in the Millepore and Whitwell Oolites, the Yons
Nab Beds and Upper Limestone, and in the Basement Beds below the Cave Oolite.

Eocytheridea faveolata sp. nov.
(Pl. 6, figs. 4-0)

DiaGnosis. Eocytheridea, with strong pitting producing a reticulate ornament.

Ho.otyPe. Io.1067, Yons Nab Beds (bed 7, Bate 1959 : 158), Cayton Bay.

PARATYPES. Io.1068-71, from the Millepore Oolite, Cayton Bay ; Whitwell
Oolite, Seamer Lime and Stone Co’s. Quarry ; Cave Oolite, Eastfield Quarry ;
and Upper Limestone, Stonecliff Wood.

DESCRIPTION. Carapace oval-subquadrate, elongate in the male dimorph.
Greatest length through midpoint ; greatest height median in adult instars, in the
anterior third in juveniles ; greatest width in the posterior third. Shell surface
strongly pitted, the pits being so close that a reticulate ornament is produced.
The specific name given to this ostracod refers to the nature of the pits, which are
5-6 sided, in many cases with a large, circular, normal pore canal opening at the
centre. Left valve larger than the right, which it overlaps along the ventral margin,
in the region of the anterior cardinal angle and along the posterodorsal slope.
Dorsal margin slightly convex, sloping to the posterior ; cardinal angles distinct.
Anterior broadly rounded ; posterior more narrowly rounded. Ventral margin
convex, incurved anteromedially. Right valve smaller, more elongate than the left,
and with a noticeable dorsomedian convexity which projects above the dorsal
margin. Hinge, as seen in a single right valve, rather poorly preserved, probably
hemimerodont. Inner margin and line of concrescence coincide ; anterior radial
pore canals long, slightly curved and grouped largely in the anteroventral sector ;
exact number not seen but there appear to be about 10. Muscle scars of type C,
as for genus.

Dimensions

HoLotyPe. lo.1067, female carapace (PI. 6, figs. 5-8), length 0-71 mm.; height
0-45 mm.; width 0-41 mm.

OSTRACODA FROM THE MILLEPORE SERIES, YORKSHIRE 21

PARATYPES. I[o.1068, juvenile carapace, length 0-61 mm.; height 0:35 mm.;
width 0-31 mm. l[o.1069, male carapace (Pl. 6, fig. 9), length 0-78 mm.; height
0-42 mm. (damaged) ; width 0-42 mm. Io.1070, female right valve (PI. 6, fig. 4),
length 0-61 mm.; height 0-35 mm.

Remarks. E. faveolata appears to be closely related to E. lacunosa from which
it differs only in the closeness of the surface pitting. In the latter species the pits
are widely scattered over the shell surface. Here, however, the pits become so
closely arranged that a reticulate ornament is produced. This type of reticulation
is different from that described in E. reticulata sp. nov., where the ornament is
produced by ridges rather than by pits. £. faveolata is not a common species,
being found only at the localities mentioned for the type material.

Eocytheridea lacunosa Bate

1963a Focytheridea lacunosa Bate : 36, pl. 8, figs. 6-11, pl. 9, figs. 1-8.

REMARKS. Although it seems probable that this species gave rise to E. faveolata
in the Millepore Series, it is not entirely replaced by the latter, a single specimen
(female dimorph) being found at the base of the Yons Nab Beds, Cayton Bay.

Eocytheridea reticulata sp. nov.
(Pl. 6, figs. 10, 11, Pl. 7, figs. r-5)

Dracnosis. Eocytheridea with fine reticulate ornament of obliquely transverse
and longitudinal ridges.

HorotyPe. Io.1065, Millepore Oolite, Osgodby Nab.

PARATYPE. Io.1066, Kirton Cementstone Series, Greetwell Quarry, Lincolnshire
(for locality see Bate 1963 : 177).

DESCRIPTION. Carvapace subquadrate in the female dimorph, elongate in the
male. Greatest length through midpoint ; greatest height in the anterior third ;
greatest width in the posterior third. Shell surface reticulate. Left valve larger
than the right, which it overlaps along the ventral margin and to a lesser extent
in the region of the cardinal angles. Dorsal margin straight, sloping towards the
posterior. Cardinal angles broadly rounded. Anterior and posterior margins
uniformly rounded. Ventral margin convex, anteromedially incurved. Right
valve smaller than the left, otherwise similar in outline. Hinge hemimerodont,
only seen in the right valve (male dimorph), where there are 5 anterior and 6 posterior
teeth, dorsally bifid. Median groove long and smooth. Other internal details
not seen.

Dimensions

Hototypre. Io.1065, female carapace (Pl. 6, figs. 10, 11, Pl. 7, figs. 1, 2), length
0-59 mm.; height 0-35 mm.; width 0-32 mm.

PARATYPE. Io.1066, male right valve (Pl. 7, figs. 3-5), length 0-70 mm.; height
0-34 mm.

nN
N

OSTRACODA FROM THE MILLEPORE SERIES, YORKSHIRE

ReMARKS. Although only two specimens of this species have so far been found,
they are sufficiently distinct as to be considered a separate species, differing from
E. faveolata in size, in the dorsal margin (not strongly angled in the right valve)
and in the reticulate ornament which is produced by ridges rather than by pitting.

Genus PRAESCHULERIDEA Bate 1963
Praeschuleridea subtrigona (Jones & Sherborn)

1888 Cytheridea subtrigona Jones & Sherborn : 265, pl. 2, fig. 9a—c.
1963 Pyraeschulevidea subtrigona (Jones & Sherborn) Bate : 207, pl. 12, figs. 12-16, pl. 13,
figs. I-9.
1963a Pyraeschulevidea subtrigona (Jones & Sherborn) ; Bate : 41.
REMARKS. Two subspecies of Praeschuleridea subtrigona, distinguished by the
size of the adult carapace, are here recognized. They are: P. subtrigona subtrigona
(Jones & Sherborn) and P. subtrigona magna subsp. nov.

Praeschuleridea subtrigona subtrigona (Jones & Sherborn)

Synonymy. As for the species.

Diacnosis. A subspecies of Praeschuleridea subtrigona with oval-subtrigonal,
punctate carapace. Length of adult carapace of the order of (female) 0:56 mm. ;
(male) 0-58 mm.

REMARKS. P. subtrigona subtrigona, when it occurs in a sediment, is very common,
forming a large proportion of the ostracod fauna. It is present in the Cave Oolite,
Eastfield Quarry, in the Whitwell Oolite, Seamer Lime and Stone Co’s. Quarry and
at Bulmer ; less certainly within the Millepore Oolite, Cloughton.

The instar at which dimorphism is fully developed is taken to represent the adult :
as such the subspecies attains the same dimensions as recorded in Bate (1963 : 209).
The maximum length of the female carapace is probably little more than 0:56 mm.
and that of the male 0-58 mm. _ This is important, for, at many horizons throughout
the Millepore Series, an ostracod virtually identical with P. subtrigona subtrigona
occurs, having a maximum length of the order of 0-73 mm. for the female dimorph
and 0-83 mm. for the male. The very slight differences which exist in the outline
of this larger ostracod, for example, a slightly less steeply inclined and more convex
dorsal margin in the left valve of the female dimorph, are probably related to the
increase in size.

Only in one sample (out of a total of over 60) have the large and small specimens
been found together, the presence of dimorphism in the smaller ostracod indicating
that they are not simply young instars of the larger. This association is most
probably due to the sample in this case taking in more than one bedding plane.
The larger specimens are considered to be a separate subspecies of P. subtrigona,
and are described below.

OSTRACODA FROM THE MILLEPORE SERIES, YORKSHIRE 23

Praeschuleridea subtrigona magna subsp. nov.
(Pl. 7, figs. 6-11, Pl. 8, figs. 1-6)

Diacnosis. A subspecies of Praeschuleridea subtrigona with oval-subtrigonal,
punctate carapace. Normal pore canals prominent. Length of adult carapace of
the order of (female) 0-73 mm., (male) 0-83 mm.

Hototyre. Io.1077, Yons Nab Beds (bed 7, Bate 1959 : 158), Cayton Bay.

PARATYPES. Io.1078-87, Io.1139-49, horizon and locality as above, and from
the Whitwell Oolite, Seamer Lime and Stone Co’s. Quarry, and the Upper Limestone,
Stonecliff Wood.

DESCRIPTION. Carapace ovoid-subtrigonal, strongly dimorphic, the males being
quite elongate. Shell surface very finely punctate with large, circular, normal pore
canals prominent. The oblique swelling, which probably represents an eye swelling
in this species, is here only well developed in the right valve of the male dimorph ;
it is barely discernible in the right valve of the female, and not at all in the left
valve of either sex. Greatest length passes through midpoint ; greatest height
and width median. Left valve larger than right, which it overlaps along the ventral
margin and overreaches along the dorsal margin and around the anterior. Dorsal
margin short, slightly convex, sloping posteriorly. Anterior cardinal angle at
valve middle, giving the dorsal outline an “‘ umbonate”’ appearance ; posterior
cardinal angle may be rounded or sharply distinct. Ventral margin convex ;
anterior and posterior margins rounded. Right valve more elongate than the left
with distinct cardinal angles. Both valves possess a shallow groove which extends
around the anterior margin, giving the impression of an outer rim. Hinge
paleohemimerodont with 6, dorsally bifid, terminal teeth in the right valve and
elongate, coarsely loculate sockets connected by a median groove in the left.
Inner margin and line of concrescence coincide ; anterior radial pore canals few in
number and curved, approximately Io anteriorly and 4 posteriorly. Muscle scars,
type C : anteromedian antennal scar rounded.

Dimensions

Hototyre. Io.1077, female carapace (PI. 7, figs. 6-9), length 0-73 mm.; height
0-48 mm.; width 0-40 mm.

PARATYPES. I[o.1078, male carapace (PI. 8, figs. 1-4), length 0-80 mm.; height
0-48 mm.; width 0:36 mm. lIo.1079, female carapace (Pl. 8, figs. 5, 6), length
0-64 mm.; height 0-43 mm.; width 0-34 mm. I[o.1080, female left valve (Pl. 7,
fig. 11), length 0-70 mm.; height 0-45 mm. _ Io.1087, male carapace, length 0-83 mm. ;
height 0-49 mm.; width 0-43 mm.

REMARKS. P. subtrigona magna is very close to P. subtrigona subtrigona but
differs primarily in respect of size, although the former tends to be more ovoid in
outline, without the strong posterior angularity of the latter. Smaller specimens
of P. subtrigona magna do show a greater degree of angularity, however. The female
dimorphs of this new subspecies are very similar externally to Asciocythere lacunosa
Bate (1963a : 34, pl. 6, figs. 3-9, pl. 7, figs. 1-6), from which they can be distinguished

24 OSTRACODA FROM THE MILLEPORE SERIES, YORKSHIRE

by the more distinctly ‘“‘ umbonate”’ dorsal outline and tapered posterior margin,
the latter being rather flattened in A. lacunosa. Internally the two ostracods are
easily distinguishable by the type of hinge present.

P. subtrigona magna occurs largely in the shales and impure oolites of the Millepore
Series as exposed in the north western and north eastern outcrops, and may well
have favoured the lower salinity which was almost certainly present close to the
delta. It is a very abundant ostracod, and like the other subspecies, forms the
bulk of the ostracod fauna when present.

Praeschuleridea ventriosa (Plumhoff)
1963 Procythervidea ? ventyiosa Plumhoff : 36.
1963 Procytheridea ventriosa Plumhoff ; Fischer : 298, text-fig. 2.

RemARKS. As mentioned in Bate (1963a@ : 46), although Plumhoff (1963 : 36)
attributes the species Procytheridea ? ventriosa to Fischer, the fact that Fischer’s
publication (1963) was still in press at that time, means that the species name must
be attributed to Plumhoff.

Praeschuleridea ventriosa ventriosa (Plumhoff)
1962 Ostracod No. 1o1 Klinger : 78, 115, pl. 114, fig. 3, pl. 14, fig. 57, table 7.
1962 Ostracod No. tor Klingler ; Brand & Fahrion : 127, pl. 16 (fauna 1), fig. 2, ? (fauna 6)
fig. 6, pl. 17 (fauna 9), fig. 7 (non pl. 20, fig. ro).
1963 Pyvocytheridea ? ventriosa ventriosa Plumhoff : 36, pl. 6, figs. 95-98.
1963a Praeschuleridea ventriosa ventriosa (Plumhoff) Bate : 39, pl. 10, figs. 8-13, pl. 11, figs. 1-9,
pl. 12, figs. 1-4, 7, 8.

REMARKS. Three carapaces (2 male and 1 female) have been found at the base
of the Yons Nab Beds, Cayton Bay. This species has not, so far, been found
elsewhere in the Millepore Series.

The illustrations of ostracod No. ror Klingler ; Brand & Fahrion (1962, pl. 16,
(fauna 6) fig. 6, and pl. 17, (fauna 9) fig. 7), are such that it is impossible to state
with certainty that they are of this species. Fig. 10, pl. 20, is most definitely not
conspecific. The examination of Fischer’s material A.R.1110/186—187 kindly lent
by Dr. F. Westphal, Tibingen, has shown that his Procytheridea ventriosa
(1963 : 208, text-fig. 2) belongs to the subspecies Praeschuleridea ventriosa angulata
(Plumhoff 1963 : 36, pl. 6, figs. gg-100 ; pl. 7, figs. 101-103).

Family CYTHERURIDAE Miiller 1894
Genus CYTHEROPTERINA Mandelstam 1956

Cytheropterina plana sp. nov.

(Pl. 8, figs. 7-10, Pl. 9, figs. 1-4)
DiaGnosis. Cytheropterina without ornamentation.
Ho.otyPe. Io.1088, Millepore Oolite, Cloughton Wyke.

PARATYPES. Io.1089-92, horizon and locality as above, and from the Upper
Limestone, Stonecliff Wood ; and the Yons Nab Beds, Cayton Bay.

OSTRACODA FROM THE MILLEPORE SERIES, YORKSHIRE 25

DESCRIPTION. Carapace convex in dorsal view, oval in lateral view. Sexual
dimorphism indicated by the more elongate males. Greatest length below mid-
point ; greatest height and width median. Shell surface smooth. Left valve
larger than the right, which it overlaps slightly along the ventral margin and strongly
overreaches along the dorsal margin. Dorsal margin in both valves convex ;
arched in the female dimorph, elongate in the male. Cardinal angles rounded.
Anterior rounded ; posterior triangular with a strongly concave posterodorsal
slope and a convex posteroventral slope. Ventral margin convex ; ventrolateral
margin alaeform, extending below the ventral surface. Internal details not seen.

Dimensions

‘Hototyre. Io.1088, female carapace (Pl. 8, figs. 7-10), length 0-47 mm.;
height 0-34 mm.; width 0-32 mm.

ParATYPES. Io.1089, male carapace (Pl. 9, figs. 1-4), length 0-60 mm.; height
0:36 mm.; width 0-35 mm. lIo.10go, female carapace, length 0-44 mm.; height
0°33 mm.; width 0-31 mm. lIo.1og1, female carapace, length 0-37 mm.; height
0-25 mm.; width 0:27 mm.

Remarks. C. plana is close to C. triebela Neale (1962 : 437, pl. 3, fig. 7, pl. 4,
figs. 1-4, pl. 12, fig. 33), but differs in being less elongate in outline, with the alae
not backwardly projected, and lacking the ventral ornamentation present in C.
triebeli. C. plana is also dimorphic. Cytheropteron purum Schmidt (1954 : 88,
pl. 5, figs. 3-6, pl. 7, figs. 25-29, pl. 8, figs. 30, 31) is also very close to C. plana,
but is more elongate in outline, the latter having a greater shell height in proportion
to length than C. purum. C. plana is an uncommon species, found only in the
Millepore Oolite and in the Yons Nab Beds and Upper Limestone.

Family PROTOCYTHERIDAE Lyjubimova 1955
Subfamily KIRTONELLINAE Bate 1963
Genus KIRTONELLA Bate 1963

Kirtonella plicata Bate

1963 Kirtonella plicata Bate : 210, pl. 13, figs. ro-19, pl. 14, figs. 1-6, 11, 12.
1963a Kirtonella plicata Bate ; Bate : 43.

REMARKS. Two specimens, a complete carapace and a right valve, both female
dimorphs, have been found in a sandy limestone (bed 7, Bate 1959 : 158) towards
the top of the Yons Nab Beds, Cayton Bay.

Kirtonella reticulata sp. nov.
(Pl. 9, figs. 5-15, Pl. 10, figs. 1-2)
Diacnosis. Kzirtonella with strongly reticulate ornament.
HototyrPe. Io.1093, Yons Nab Beds (bed 2, Bate 1959 : 159), Cayton Bay.
PARATYPES. Io.1094—1102, horizon and locality as above, from the Millepore
Oolite, Osgodby Nab and Cloughton ; and the Whitwell Oolite, Seamer Lime and
Stone Co’s. Quarry.

26 OSTRACODA FROM THE MILLEPORE SERIES, YORKSHIRE

DEscRIPTION. Cavapace subquadrate in side view, narrow in dorsal view with
a slight median constriction, tapering more strongly to the posterior in the female
dimorph, male elongate. Greatest length passes through midpoint, greatest height
in the anterior third, greatest width in the posterior third. Anterior high, broadly
rounded ; posterior tapering, triangular with a concave posterodorsal slope and a
convex posteroventral slope. Dorsal margin slightly concave in the left valve,
convex in the right ; cardinal angles broadly rounded. Ventral margin incurved
anteromedially. Ventrolateral margin of both valves extends below the ventral
surface, particularly posteroventrally. Shell surface strongly reticulate, the pits
produced being 5-6 sided. The reticulate ornament is arranged in the form of
longitudinal wrinkles in the ventral and ventrolateral regions. A distinct eye
swelling is present to one side of the anterior cardinal angle. The muscle scars
appear externally as smooth, upstanding prominences on the carapace, indicating
a subvertical row of 4 adductor scars with an anterodorsal antennal scar and an
anteroventral mandibular scar. The shape of the antennal scar cannot, however,
be made out. The left valve is larger than the right, which it overlaps along the
ventral margin and overreaches along the dorsal margin. Hinge antimerodont :
left valve with terminal loculate sockets and a denticulate median bar, accommoda-
tion groove shallow. Right valve with approximately 5 terminal teeth, median
groove tending to be overhung by the dorsal margin of the valve. Inner margin
and line of concrescence coincide ; radial pore canals straight, simple and widely
spaced, approximately Io anteriorly and 5 posteriorly.

Dimensions

Hototyre. Io.1093, female carapace (PI. 9, figs. 5-8), length 0-54 mm.; height
0-32 mm.; width 0-27 mm.

PARATYPES. Io.1094, female left valve (Pl. 9, fig. 16), length 0-51 mm.; height
0-33 mm. Io.1095, female right valve (PI. 10, figs. 1, 2), length 0-51 mm.; height
0:29 mm. _ Io.1096, male carapace (PI. 9, figs. 10-13), length 0-55 mm.; height 0-31
mm.; width o-26mm. Io.1097, male carapace, length 0-66 mm.; height 0-34 mm. ;
width 0-32 mm. lIo.1098, female carapace (Pl. 9, figs. 14, 15), length 0-48 mm.;
height 0-28 mm.; width 0-26 mm. Io.1099, female carapace (Pl. 9, fig. 9), length
0-50 mm.; height 0-30 mm.; width 0-26 mm.

ReMARKS. K. reticulata can be distinguished from K. plicata by its ornament.
It is common within the shale facies of the Yons Nab Beds, fairly common, when
present, in the Millepore Oolite (Osgodby Nab), but rare in the Millepore Oolite of
Cloughton and the Whitwell and Cave Oolites.

Genus EKTYPHOCYTHERE Bate 1963

Ektyphocythere triangula (Brand)

1961 Procytheridea triangula Brand : 161, pl. I, figs. 11-14.

1962 Procythevidea triangula Brand ; Brand & Fahrion : 129, 133, pl. 17 (fauna 9), fig. 9,
pl. 20, figs. 27, 28.

1963 Ektyphocythere triangula (Brand) Bate : 214, pl. 15, figs. 5-18.

1963a Ektyphocythere triangula (Brand) ; Bate : 44.

OSTRACODA FROM THE MILLEPORE SERIES, YORKSHIRE 27

REMARKS. This ostracod is more frequently encountered in the Cave Oolite
than elsewhere in the Millepore Series. It is not, however, common and shows a
marked decrease compared to the numbers present in the Lower Lincolnshire
Limestone. FE. triangula occurs also in the Whitwell Oolite (Seamer Lime and
Stone Co’s. Quarry, and near Bulmer), Millepore Oolite (Cloughton), and at the
base of the Yons Nab Beds, Cayton Bay.

Genus SOUTHCAVEA nov.

Dracnosis. Kirtonellinae with oval subquadrate carapace, ventrolateral border
slightly overhanging ventral margin. Shell surface variously ornamented. Species
may be dimorphic. Hinge hemimerodont/antimerodont : median hinge bar of
left valve very finely denticulate along dorsal surface, in lateral view apparently
smooth. Muscle scars as for family. Inner margin and line of concrescence
coincide ; radial pore canals straight, 8-10 anteriorly. Left valve larger than
right.

Type Species. Southcavea reticulata sp. nov.

REMARKS. The genus (feminine) takes its name from South Cave, the locality
of the type species. Three species are placed in it : S. bajociana (Bate 1963) ;
S. grandis sp. nov., and S. reticulata sp. nov. The nature of the hinge is such that
in most specimens it appears to be hemimerodont, but it is antimerodont in two
species. However, as the denticulation of the median bar, left valve, is so fine
as to be barely distinguishable, the presence of a species with a truly hemimerodont
hinge within the genus is not ruled out.

Southcavea reticulata sp. nov.
(Pl. ro, figs. 3-14, Pl. 11, figs. 1-4)

Diacnosis. Southcavea with coarse reticulate ornament superimposed upon a
punctate shell surface.

Hototypee. I[o.1103, Cave Oolite, Eastfield Quarry.

PARATYPES. Io.1104-17, and Io.1138, horizon and locality as above, and from
the Millepore Oolite, Osgodby Nab ; Whitwell Oolite, Seamer Lime and Stone
Co’s. Quarry, and from the Cementstone Series of the Lower Lincolnshire Limestone,
Kirton Lindsey, Lincolnshire (for locality see Bate, 1963 : 177).

DESCRIPTION. Carapace subquadrate in side view, convex in dorsal view.
Dimorphism strongly developed, the more elongate specimens considered to be males.
Greatest length passes through midpoint, greatest height in the anterior third,
though because of the convexity of the ventrolateral margin this may be just
behind valve middle in the male dimorph the greatest height is in fact behind
valve middle. Greatest width in both dimorphs in the posterior half. Dorsal
margin slightly concave in the left valve, convex in the right ; cardinal angles
broadly rounded ; anterior and posterior rounded ; ventral margin anteromedially
incurved ; ventrolateral margin convex, overhanging the ventral surface, particu-
larly just behind valve middle. Shell surface coarsely reticulate, the network of

28 OSTRACODA FROM THE MILLEPORE SERIES, YORKSHIRE

ridges producing rather large, shallow, irregularly sided pits which are strongly
punctate. Ventral surface ornamented with longitudinal ridges which converge
towards the posterior. Left valve larger than the right, which it overlaps evenly
along the ventral margin, and overreaches along the antero- and postero-dorsal
slopes. Hinge antimerodont ; left valve with terminal loculate sockets and a
broad, very finely denticulate, median bar. Accommodation groove virtually
absent, represented by a narrow ledge. In the right valve the hinge has not been
clearly seen, except for the median groove which is here overhung by the dorsal
edge of the valve. Muscle scars of type D, consisting of a subvertical row of 4
adductor scars with an anterodorsal, V-shaped antennal scar, and a small, rounded,
anteroventral mandibular scar. Inner margin and line of concrescence coincide,
the duplicature being quite broad. Radial pore canals straight ; anteriorly widely
spaced and about 8 in number ; 3 posteriorly.

Dimensions

HoLotypPe. I[o.1103, female left valve (Pl. ro, figs. 3-6), length 0-54 mm.;
height 0:34 mm.

PARATYPES. lIo.1104, male left valve (Pl. 10, fig. 13), length 0-60 mm.; height
0-33 mm. lIo.1105, female carapace (Pl. ro, figs. 8-11), length 0-48 mm.; height
0-31 mm.; width 0-32 mm. Io.1106, female left valve (Pl. 10, fig. 14), length
0-49 mm.; height 0-30 mm. Io.1107, female right valve (PI. ro, fig. 12), length 0-51
mm.; heighto-30mm. _ Io.1108, female left valve, length 0-51 mm.; height 0-31 mm.
Io.1109, male left valve (Pl. ro, fig. 7), length 0-62 mm.; height 0-32 mm. [o.1110,
male carapace (PI. 11, figs. 1-4), length 0-65 mm.; height 0-37 mm.; width 0-36 mm.

REMARKS. S. veticulata is quite common in the Cave Oolite, but very rare else-
where at this horizon, only one specimen having been found in the Whitwell Oolite
(Seamer Lime and Stone Co’s. Quarry), and 2 specimens from the Millepore Oolite
(Osgodby Nab). The species is also present in the Lower Lincolnshire Limestone
(Kirton Cementstone Series), Kirton Lindsey (for locality see Bate, 1963), where it
is, however, very rare.

In common with many other species of ostracod, female dimorphs outnumber
males, of which only 3 specimens have been found.

Southcavea bajociana (Bate)
1963a Kinkelinella ? bajociana Bate : 44, pl. 13, figs. 12-19.

REMARKS. This species when first described was tentatively placed in the genus
Kinkelinella Martin (1960 : 130). However, through the kindness of Dr. E. Triebel,
I have since been able to examine paratype material of the type species, K. tenwico-
stati Martin (1960: 131, pl. 12, figs. 12-15). The latter is almost alaeform with
regard to its ventrolateral extension, whilst the anterior and posterior marginal
borders are strongly delimited from the central inflation of the valve. These two
characters, not particularly clear in the original illustration, are sufficient to remove
the present species from the genus.

OSTRACODA FROM THE MILLEPORE SERIES, YORKSHIRE 29

S. bajociana was originally considered to possess a hemimerodont hinge.
Subsequently a complete carapace has been opened, using an ultrasonic vibrator.
Although the median groove in the right valve appears to be smooth, the median
bar in the left valve possesses very fine denticles along its dorsal surface. The
hinge is, therefore, considered to be antimerodont.

Southcavea grandis sp. nov.
(Pl. 11, figs. 5-13, Pl. 12, fig. 1)

Diacnosis. Southcavea with elongate-subquadrate carapace. Ornament
uniformly reticulate. Radial pore canals short, straight, anteriorly 7-8 in number.

Horotypee. lIo.1119, Cave Oolite, Eastfield Quarry.

PARATYPES. [o.1120—22, horizon and locality as above, and from the Whitwell
Oolite, nr. Bulmer.

DESCRIPTION. Cavrapace elongate-subquadrate in side view, with a strong,
uniformly reticulate ornament. Greatest length through midpoint, greatest height
median or slightly behind midpoint, greatest width in the posterior third. Ventro-
lateral border convex, overhanging the ventral surface, particularly behind valve
middle. Left valve larger than the right, which it overlaps along the ventral margin
and overreaches along the dorsal margin. Dorsal margin in both valves slightly
convex with broadly rounded cardinal angles. Anterior broadly rounded, posterior
more narrowly rounded. Ventral margin medially incurved. Hinge not deter-
mined. Muscle scars consist of a subvertical row of 4 oval adductor scars, a
V-shaped anterodorsal antennal scar, and a rounded anteroventral mandibular scar.
The antennal scar is produced by the fusion of a large, elongate-oval scar and a small
scar situated anteroventrally to it. Inner margin and line of concrescence coincide,
duplicature rather narrow ; anterior vadial pore canals short, straight, and about
7-8 in number.

Dimensions

Hototyre. lIo.1119, carapace (Pl. 11, figs. 5—7, 13), length 0-70 mm. ; height
0-42 mm. ; width 0-42 mm.

PARATYPE. I[o0.1120, carapace (Pl. 11, figs. 8-11), length 0-55 mm. ; height
0:36 mm. ; width 0:34 mm.

REMARKS. S. gvandis is a rare ostracod confined, so far, to the Cave Oolite and
the Whitwell Oolite (Bulmer). This species is considerably larger than the others
placed in the genus, from which it also differs in the possession of a uniformly
reticulate ornament, lacking the punctae of S. reticulata.

Genus SYSTENOCYTHERE Bate 1963

Systenocythere exilofasciata Bate
1963 Systenocythere exilofasciata Bate : 212, pl. 14, figs. 7-10, 13-17, pl. 15, figs. 1-4.
1963a Systenocythere exilofasciata Bate ; Bate : 45.
Remarks. This ostracod is fairly well represented throughout the Cave and
Whitwell Oolites. It is noticeably reduced numerically in the Millepore Oolite and

30 OSTRACODA FROM THE MILLEPORE SERIES, YORKSHIRE

in the Yons Nab Beds and Upper Limestone. As the restriction of this species does
not appear to be directly related to facies, it might well be that a decrease in salinity
resulting from the proximity of the northern delta had a restricting effect.

Systenocythere ? sp.
(Pl. 12, figs. 2-5)

Remarks. A single carapace, found in the Whitwell Oolite, Stonecliff Wood,
with a punctate surface is similar in outline to the female dimorphs of Systenocythere
exilofasciata, from which it can be distinguished by surface ornamentation.

Dimensions
Io.1118, carapace (Pl. 12, figs. 2-5), length 0:57 mm. ; height 0-36 mm. ; width
0-36 mm.

INCERTAE SEDIS

A number of ostracods occur within the Millepore Series as complete carapaces
only, no internal details being known. These ostracods are accordingly not assigned
to any genus, but are merely identified by their registration numbers.

Io.1123-25, Pl. 12, figs. 6-11.

REMARKS. Carapace ovoid, dimorphic ; surface smooth, although in Io.1125
the shell surface possesses irregular transverse wrinkles. A characteristic feature of
this species is the deep furrow which runs obliquely below the anterior cardinal
angle. This is a rare ostracod which so far has been found only within the Millepore
Oolite of Yons Nab, and the Whitwell Oolite at Westow.

Dimensions

Io.1123, female carapace (Pl. 12, figs. 6-9), length 0-62 mm. ; height 0-43 mm. ;
width o-41 mm. lIo.1124, male carapace, length 0-70 mm. ; height 0-42 mm. ;
width 0-40 mm. lIo.1125, male carapace (Pl. 12, figs. 10, 11), length 0-74 mm. ;
height 0-40. ; width 0-44 mm.

Io.1126-7 & Io.1150, Pl. 13, figs. 1-4.

REMARKS. Only 3 specimens (2 carapaces and a right valve) of this ostracod
have so far been found, and all are from the Cave Oolite. In outline they are very
close to Orthonotacythere ? voigterensis Bartenstein & Brand (1959: 232, pl. 29,
fig. 7a—c), but do not possess its ornamentation.

Dimensions

Io.1127, carapace (Pl. 13, figs. 1-4), length 0-55 mm. ; height 0:35 mm. ; width
0:37 mm.

Io.1128 and [o.1151, Pl. 13, figs. 5-8.

REMARKS. Two carapaces found in the Millepore Oolite, Cayton Bay, have
parallel-sided carapaces and a weak reticulate ornament. They may belong to the
genus Homocytheridea Bate 1963a.

OSTRACODA FROM THE MILLEPORE SERIES, YORKSHIRE 31

Dimensions

Io.1128, carapace (Pl. 13, figs. 5-8), length 0-71 mm. ; height 0-32 mm. ; width
0:36 mm.

Io.1129-31, Pl. 13, figs. 9-12.

REMARKS. Carapace subquadrate with the greatest height behind valve centre.
Dimorphic, the female possessing a marked swelling in the region of the posterior
cardinal angle. This ostracod is largely restricted to the Millepore Oolite and Yons
Nab Beds, but has been found in the Whitwell Oolite. It is never common.

Dimensions

Io.1129, female carapace (PI. 13, figs. 11, 12), length 0-68 mm. ; height 0-41 mm. ;
width 0-40 mm. Io.1130, male carapace (Pl. 13, figs. 9, 10), length 0-83 mm. ;
height 0-43 mm. ; width 0-44 mm.

Io.1132-3, Pl. 14, figs. 1-4.

Remarks. A large, oval ostracod in which the greatest height of the carapace is
median and the anterior is more narrowly rounded than the posterior. Left valve
larger than the right, with a flap of the right valve overlapping the left midventrally.
Two specimens have been found, one in the Whitwell Oolite, Seamer Lime and Stone
Co’s. Quarry (figured), and the other from the Yons Nab Beds, Cayton Bay.

Dimensions

Io.1132, carapace (Pl. 14, figs. 1-4), length 0-98 mm. ; height 0-51 mm. ; width
0:48 mm.

To.1134, Pl. 14, figs. 5-8.

Remarks. A single carapace, strongly punctate, found in the uppermost part of
the Millepore Oolite, Cayton Bay.

Dimensions

Io.1134, carapace (Pl. 14, figs. 5-8), length 0-65 mm. ; height 0-40 mm. ; width
0-39 mm.

III REFERENCES

ALEXANDER, C. I. 1929. Ostracoda of the Cretaceous of North Texas. Bull. Univ. Tex.
Bur. econ. Geol., Austin, 2907 : 1-137, pls. I-10.

BartTEnsTEIN, H. & Branpb, E. 1959. In BARTENSTEIN, H. Feinstratigraphisch wichtige
Ostracoden aus dem nordwestdeutschen Valendis. Paldont. Z., Stuttgart, 33 : 224-246,
pls. 27-31.

Bate, R. H. 1959. The Yons Nab Beds of the Middle Jurassic of the Yorkshire Coast.

Proc. Yorks. Geol. Soc., Leeds, 32 : 153-164, pl. 3.

1963. Middle Jurassic Ostracoda from North Lincolnshire. Bull. Brit. Mus. (Nat. Hist.)

Geol., London, 8, 4 : 173-219, pls. I-15.

— 1963a. Middle Jurassic Ostracoda from South Yorkshire. Bull. Brit. Mus. (Nat. Hist.)
Geol., London, 9, 2 : 19-46, pls. 1-13.

Brann, E. 1949. Neue Ergebnisse zur mikropalaontologischen Gliederung des nordwest-
deutschen Dogger und Valendis : 335-348, pls. 10-15. Jn Bentz, A. (editor), Evdél und
Tektonik in Norvdwestdeutschland, 387 pp., 15 pls., Hannover-Celle.

32 OSTRACODA FROM THE MILLEPORE SERIES, YORKSHIRE

1961. Jn BrRanp, E. & Marz, H. Drei neue Procytheridea-Arten und Ljubimovella n.g.
aus dem N.W.-deutschen Bajocien. Senck. leth., Frankfurt a.M., 42 : 157-173, pls. 1, 2.
Branp, E. & Fanrion, H. 1962. Dogger N.W.-Deutschlands : 123-158, pls. 16-21. In

Simon, W. & BARTENSTEIN, H. (editors), Leitfossilien der Mikropaldontologie. vili+ 432 pp.,
59 pls. Berlin.

Branpb, E. & Matz, H. 1962. Ostracoden-Studien im Dogger, 4 : Fuhrbergiella n.g. Senck.
leth., Frankfurt a.M., 43 : 1-39, pls. 1-6.

FISCHER, W. 1963. Neue Arten der Ostracoden-Gattung Procytheridea Peterson 1954 aus
dem Oberen Lias Schwabens. N. Jb. Min. Geol.-Paldont., Stuttgart, 6 : 295-300, 2
text-figs.

Hupreston, W. H. 1874. The Yorkshire Oolites—Pt. 1. Proc. Geol. Ass. Lond., 3, 7:
283-333.

Jones, T. R. 1849. A Monograph of the Entomostraca of the Cretaceous Formation of
England. Palaeontogr. Soc. |Monogr.| London. 40 pp., 7 pls.

—— 1884. Notes on the Foraminifera and Ostracoda from the deep boring at Richmond.
Quart. J. Geol. Soc. Lond., 11 : 765-777, pl. 34.

Jones, T. R. & HinpeE, G. J. 1890. A Supplementary Monograph of the Cretaceous Ento-
mostraca of England and Ireland. Palaeontogy. Soc. [Monogr.) London. vili+7o pp.,
4 pls.

Jones, T. R. & SHERBORN, C. D. 1888. On some Ostracoda from the Fullers-earth Oolite
and Bradford Clay. Proc. Bath nat. Hist. Fid. Cl., 6 : 249-278, pls. 1-5.

Kent, P. E. 1955. The Market Weighton Structure. Pvoc. Yorks. Geol. Soc., Leeds, 30,
I2 : 197-227.

KLINGLER, W. 1962. Lias Deutschlands : 73-122, pls. 9-15. In Simon, W. & BARTENSTEIN,
H. (editors), Leitfossilien dey Mikvopaldontologie. vili+432 pp., 59 pls. Berlin.

Lyuspimova, P. S. 1955. Ostracodes of the Mesozoic deposits of the Volga-Ural region.
Trud. vses. neft.-nauch. issled. geol. Inst. (VNIGRI) Leningrad (N.S.), 84 : 3-189, pls. 1-13.
{In Russian. }

Lutze, G. F. 1960. Zur Stratigraphie und Palaontologie des Callovien und Oxfordien in
Nordwest-Deutschland. Geol. J/b., Hannover, 77 : 391-532, pls. 26—46.

Martin, G. P. R. 1960. Im Horrmann, K. & Martin, G. P. R. Die Zone des Dactylioceras
tenuicostatum (Toarcien, Lias) in N.W.- und S.W.-Deutschland. Paldont. Z., Stuttgart,
34 : 103-149, pls. 8-12.

MERTENS, E. 1956. Zur Grenzziehung Alb/Cenoman in Nordwestdeutschland mit Hilfe von
Ostracoden. Geol. Jb., Hannover, 72 : 173-230, pls. 8-14.

NEALE, J. W. 1962. Ostracoda from the type Speeton Clay (Lower Cretaceous) of Yorkshire.
Micropaleont., New York, 8 : 425-484, pls. 1-13.

OeERTLI, H. J. 1958. Les Ostracodes de l’Aptien-Albien d’Apt. Rev. Inst. franc. Pétrole,

Paris, 13 : 1,499-1,537, pls. I-9.

1959. Malm-Ostrakoden aus dem schweizerischen Juragebirge. Denkschy. schweiz.

naturf. Ges., Ziirich, 83 : 1-44, pls. 1-7.

PLuMHOoFF, F. 1963. Die Ostracoden des Oberaalenium und tiefen Unterbajocium (Jura) des
Gifhorner Troges, Nordwestdeutschland. <Abh. senckenb. naturf. Ges., Frankfurt, a.M.,
503 : 1-100, pls. 1-12.

ScuMipT, G. 1954. Stratigraphisch wichtige Ostracoden im ‘‘ Kimmeridge’”’ und tiefsten
“ Portland ”’ N.W.-Deutschlands. Paldont. Z., Stuttgart, 28 : 81-101, pls. 5-8.

Swain, F. M. 1952. Ostracoda from wells in North Carolina Pt. 2 : Mesozoic Ostracoda.
Prof. Pap. U.S. geol. Surv., Washington, 234, B : 59-95, pls. 8, 9.

SYLVESTER-BRADLEY, P. C. 1948. Bathonian ostracods from the Boueti Bed of Langton
Herring, Dorset. Geol. Mag., Lond., 85 : 185-204, pls. 12-15.

—— 1956. The Structure, evolution and nomenclature of the ostracod hinge. Bull. Brit. Mus.
(Nat. Hist.) Geol., London, 3, 1 : 1-21, pls. 1-4.

OSTRACODA FROM THE MILLEPORE SERIES, YORKSHIRE 33

TRIEBEL, E. 1941. Zur Morphologie und Okologie der fossilen Ostracoden. Senckenbergiana,
Frankfurt a.M., 23 : 294-400, pls. 1-15.
1951. Einige stratigraphisch wertvolle Ostracoden aus dem héheren Dogger Deutchlands.

Abh. senckenb. naturf. Ges., Frankfurt a.M., 485 : 87-101, pls. 44-49.

TRIEBEL, E. & BARTENSTEIN, H. 1938. Die Ostracoden des deutschen Juras, 1. Mono-
cevatina-Arten aus dem Lias und Dogger. Senckenbergiana, Frankfurt a.M. 20 : 502-518,
pls. 1-3.

VANDERPOOL, H.C. 1928. Fossils from the Trinity group (Lower Comanchean). J. Paleont.,
Tulsa, 2 : 95-107, pls. 12-14.

Van MorkuHoven, F. P. C. M. 1962. Post-Palaeozoic Ostvacoda, I. vii+204 pp., 79 figs.
Amsterdam.

EXPLANATION OF PLATES

All the specimens illustrated are now in the Department of Palaeontology,
British Museum (Natural History). All photographs, taken by the author, x 85
unless otherwise indicated.

PLATE 1

Fuhrbergiella (Praefuhrbergiella) minima sp. nov. , 6 p. II
All from Millepore Oolite, Cloughton Wyke.
Fias. 1-4. Right, left, dorsal and ventral views, female carapace. Holotype, Io. 1021.
Fies. 5-8. Left, right, dorsal and ventral views, male carapace. Paratype, Io. 1035.

Micropneumatocythere globosa sp. nov. é : ° p. 12
Fics. 9-16. Cave Oolite, Eastfield Quarry.
Fics. 17-20. Millepore Oolite, Yons Nab.
Fics. 9, 10, 15, 16. Right, left, dorsal and ventral views, female carapace. Holotype,
Io. Io1o.
Fics. 11, 12. Internal and external views, female left valve. Paratype. Io. 1012.
Fic. 13. External view, female right valve. Paratype, Io. rorgq.
Fic. 14. External view, male left valve. Paratype, Io. 1013.
Fics. 17-20. Left, right, ventral and dorsal views, male carapace. Paratype, Io. 1o11.

Bull. B.M. (N.H.) Geol. 10, 1 PLATE 1

FUHRBERGIELLA, MICROPNEUMATOCYTHERE

IPIL NARS,

Pneumatocythere cavinata sp. nov. . : c js 23}
Fics. 1-4. Upper Limestone, Stonecliff Wood.
Fics. 5-9. Cave Oolite, Eastfield Quarry.

Fics. 1-4. Left, right, dorsal and ventral views, female? carapace. Holotype, Io. 1024.
Fics. : 6. Internal and external views, female? left valve. Paratype, Io. 1029.

Fics. 7,9. Dorsal and lateral views of median hinge bar, female? left valve. Fig. 7 x 106.
Ebratype: Io. 1030.

Fic. 8. Muscle scars, female? left valve. Paratype, Io. 1028. x 200.

Asciocythere acuminata sp.nov. . F : : p. 15
Cave Oolite, Eastfield Quarry.
Fics, 1o-12. Right, left and dorsal views of complete carapace. Holotype, Io. 1072.

Bull. B.M. (N.H.) Geol. 10, 1 PLATE 2

PNEUMATOCYTHERE, ASCIOCYTHERE

PLATE 3

Asciocytheve acuminata sp. nov. . : ; ; p. 15
I'ias. 1-3. Cave Oolite, Eastfield Quarry.
['1Gs. 4, 5,9, 10. Upper Limestone, Stonecliff Wood.
I'ics. 6-8. Basement Beds, Eastfield Quarry.

I'ma. 1, Ventral view, complete carapace. Holotype, Io. 1072.

I'tas. 2, 3. External and internal views, right valve. Paratype, Io. 1075.

I'ias. 4, 5, 9, 10. Left, right, dorsal and ventral views, complete carapace. Paratype,

lo, 1073.
I'ics, 6-8, Left side, muscle sears and right side of complete carapace, Paratype, lo. 1074.

Iocythevidea ? acuta sp. nov. - : 5 p. 16
Upper Limestone, Stonecliff Wood.
I'ics. 11-14. Dorsal, ventral, left and right views, complete carapace. Holotype, lo, 1036.

Bull. B.M. (N.H.) Geol. 10, 1 PLATE 3

ASCIOCYTHERE, EOCYTHERIDEA

PLATE 4

Eocythevidea ? astvicta sp. nov. : 5 : iD. LF
Fics. 1-4. Upper Limestone, Stonecliff Wood.
Fic. 5. Basement Beds, Eastfield Quarry.
Fics. 1-4. Left, right, dorsal and ventral views, complete carapace. Holotype, Io. 1o4o.
Fic. 5. Muscle scars, juvenile carapace. Paratype, lo. 1044. 480.

Eocytheridea carinata sp. nov. : ‘ k , p. 18
Cave Oolite, Eastfield Quarry.
Fic. 6. External view, female left valve. Paratype, Io. 1051.
Fics. 7-10. Left, right, dorsal and ventral views, juvenile carapace. Paratype, Io. 1052.
Tic. 11. External view, male right valve. Paratype, lo. 1050.

Bull. B.M. (N.H.) Geol. 10, 1

EOCYTHERIDEA

Fics. 1-4.
Fics. 5-8.

Fics. 9-11.

Fic. 12. Right side of complete juvenile carapace.

PLATE 5

Eocytheridea cavinata sp. nov.
Fics. 1-4. Whitwell Oolite, Bulmer.

Fics. 5-8. Cave Oolite, Eastfield Quarry.
Right, left, dorsal and ventral views, female carapace. Holotype, Io. 1048

Right, left, dorsal and ventral views, male carapace.

Eocytheridea ? evugata sp. nov.

Paratype, lo. 1054.

Fics. 9-11. Yons Nab Beds, Yons Nab.
Fic. 12. Basement Beds, Eastfield Quarry.

Right, left and ventral views, complete carapace.

Holotype, lo. 1059.

Paratype, lo. 1060.

. 19

Bull. B.M. (N.H.) Geol. 10, 1 ; PLATE

EOCYTHERIDEA

Fic. 4. External view, female right valve.

Fics. 5-8.

Fic. 9. Right side, male carapace.

FIGS. 10, Ii.

PLATE 6

Eocytheridea ? evugata sp. nov.

Basement Beds, Eastfield Quarry.
Fics. 1-3. Left, dorsal and ventral views, juvenile carapace. Paratype, lo. 1060.

Eocytheridea faveolata sp. nov.

Fic. 4. Cave Oolite, Eastfield Quarry.
Fics. 5-8. Yons Nab Beds, Yons Nab.
Fic. 9. Whitwell Oolite, Seamer Lime and Stone Co’s. Quarry.

Paratype, Io. 1070.

Right, left, dorsal and ventral views, female carapace. Holotype, lo. 1067.

Eocythevidea reticulata sp. nov.

Paratype, lo. 1069.

Millepore Oolite, Osgodby Nab.

Left and right views, female carapace.

Holotype, Io. 1065.

. 19

Bull. B.M. (N.H.) Geol. 10, 1 PLATE 6

EOCYTHERIDEA

PLATE 7

Eocytheridea reticulata sp. nov. : : : : py Zi
Fics. 1, 2. Millepore Oolite, Osgodby Nab.
Fics. 3-5. Kirton Cementstone Series, Lower Lincolnshire Limestone, Greetwell Quarry,
Lincoln.
Fics. 1, 2. Ventral and dorsal views, female carapace. Holotype, Io. 1065.
Fics. 3-5. External, internal and dorsal views, male right valve. Paratype, Io. 1066.

Praeschuleridea subtrigona magna subsp. nov. . : : Pp. 23
Fics. 6-10. Yons Nab Beds, Yon Nab.
Fic. 11. Whitwell Oolite, Seamer Lime and Stone Co’s. Quarry.
Fics. 6-9. Right, left, dorsal and ventral views, female carapace. Holotype, lo. 1077.
Fic. 10. Muscle scars, male carapace. Paratype, lo. 1082. % 200.
Fic. 11. Anterior radial pore canals, female left valve. Paratype, Io. 1080. 150.

Bull. B.M. (N.H.) Geol. 10, 1 PLATE 7

EOCYTHERIDEA, PRAESCHULERIDEA

PLATE 8

Praeschulevidea subtrigona magna subsp. nov. . ; ' Paes
Yons Nab Beds, Yons Nab.
Fics. 1-4. Right, left, dorsal and ventral views, male carapace. Paratype, Io. 1078.
Fics. 5,6. Right and left views of female carapace. Paratype, Io. 1079.

Cytheropterina plana sp. nov. : : g ‘ Pp. 24
Millepore Oolite, Cloughton Wyke.
Fics. 7-10. Left, right, dorsal and ventral views, female carapace. Holotype, Io. 1088.

Bull. B.M. (N.H.) Geol. 10, 1 PLATE 8

PRAESCHULERIDEA, CYTHEROPTERINA

Fics. 1-4.

BY
Fics. 5-8.

PAGE G

Cytheropterina plana sp. nov. : : : 4 Ds

Millepore Oolite, Cloughton Wyke.
Right, left, dorsal and ventral views, male carapace. Paratype, lo. 1089.

Kirtonella reticulata sp. nov. : :

Fics. 5-13, 16. Yons Nab Beds (base), Yons Nab.
GS. 14, 15. Whitwell Oolite, Seamer Lime and Stone Co’s. Quarry.
Right, left, dorsal and ventral views, female carapace. Holotype, lo. 1093.

Fic. 9. Right view of female carapace. Paratype, Io. 1099.

FieGs. 10-13.
FIGs. 14, 15.

Right, left, dorsal and ventral views, male carapace. Paratype, lo. 1096.
Right and left views, female carapace. Paratype, Io. 1008.

Fic. 16. Dorsal view of hinge, female left valve. Paratype, Io. 1094.

PLATE 9

Bull. B.M. (N.H.) Geol. to, 1

CYTHEROPTERINA, KIRTONELLA

PLATE to

Kirtonella reticulata sp. nov.
Yons Nab Beds, Yon Nab.

Fics. 1,2. Internal view, showing radial pore canals. Fig.1, < 350, fig.2, x92. Female
right valve. Paratype, Io. 1095.

196725)

Southcavea reticulata sp. nov. : 19h 29)
Fics. 3-13. Cave Oolite, Eastfield Quarry.
Kirton Cementstone Series, Lower Lincolnshire Limestone, Kirton Lindsey,
Lincolnshire.
Fics. 3-6. External and internal views of valve, and lateral and dorsal views of hinge
(note fine denticulations along dorsal surface of median bar). Figs. 5 and 6, x120. Female
left valve. Holotype, Io. 1103.

Fic. 7. Dorsal view of hinge, showing fine denticulations of median bar, male left valve.
Paratype, lo. 1109. x 100.

Fics. 8-11. Right, left, ventral and dorsal views, female carapace.

Fic. 12. External view, female right valve. Paratype, Io. 1107.

Fic. 13. External view, male left valve. Paratype, Io. 1104.

Ftc. 14. Muscle scars, female left valve. Paratype, Io. 1106.

Fic. 14.

Paratype, Io. 1105.

X 320.

Bull. B.M. (N.H.) Geol. 10, 1 PLATE 10

KIRTONELLA, SOUTHCAVEA

IDI NADIE Gna

Southcavea reticulata sp. nov. : : : : 195. 27/
Cave Oolite, Eastfield Quarry.
Fics. 1-4. Left, right, dorsal and ventral views, male carapace. Paratype, Io. 1110.

Southcavea grandis sp. nov. : :
Fics. 5-7, 12, 13. Cave Oolite, Eastfield Quarry.
Fies. 8-11. Whitwell Oolite, Bulmer.
Fics. 5-7, 13. Left, right, dorsal and ventral views, complete carapace. Holotype, Io.
IIIQ.
Fics. 8-11. Left, dorsal, ventral and right views, complete carapace. Paratype, lo. 1120.
Fic. 12. Muscle scars, left valve fragment. Paratype, lo. 1121. 310.

Pp. 29

Bull. B.M. (N.H.) Geol. 10, 1 PLATE 11

SOUTHCAVEA

PLATE 12

Southcavea gvandis sp. noy. c : : ; Pp. 29
Cave Oolite, Eastfield Quarry.
Fic. 1. Anterior radial pore canals, left valve fragment. Paratype, lo. 1121. 250.

Systenocythere ? sp. : - : - 4 p. 30
Whitwell Oolite, Stonecliff Wood.
Fics. 2-5. Left, right, dorsal and ventral views, complete carapace. lo. 1118.

INCERTAE SEDIS
Fics. 6-9. Millepore Oolite, Yons Nab.
Fics. 10, 11. Whitwell Oolite, Westow.
Fias, 6-9. Right, left, dorsal and ventral views, female carapace. lo. 1123 ; Pp. 30
Fics. 10, 11. Right side and dorsal view of male carapace. Io. 1125 a c p. 30

PLATE 12

Bull. B.M. (N.H.) Geol. 10, 1

SOUTHCAVEA, SYSTENOCYTHERE, INCERTAE SEDIS

Fics
Fics
Fics

Fics.

5 Oy TOL
it, WA,

IEIL JN dh IS, 163}
INCERTAE SEDIS

Fics. 1-4. Cave Oolite, Eastfield Quarry.
Fics. 5-8. Millepore Oolite, Yons Nab.
Fics. 9-12. The Yons Nab Beds, Yons Nab.
. 1-4. Dorsal, ventral, left and right views, complete carapace.
. 5-8. Right, left, dorsal and ventral views, complete carapace.

Left and dorsal views, male carapace. lo. 1130

Left and dorsal views, female carapace.

Io. 1129

lon uiZy
Io. 1128

Pp. 30
Pp. 30
Pp. 31
[2b Su

Bull. B.M. (N.H.) Geol. 10, 1 PLATE 13

ore

:
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im
,
'
‘

INCERTAE SEDIS

PLATE 14

INCERTAE SEDIS
Fies. 1-4. Whitwell Oolite, Seamer Lime and Stone Co’s. Quarry.
Fias. 5-8. Millepore Oolite, Yons Nab.
Fics. 1-4. Left, right, dorsal and ventral views, complete carapace. Io. 1132
Fies. 5-8. Right, left, dorsal and ventral views, complete carapace. Io. 1134

PLATE 14

Bull. B.M. (N.H.) Geol. 10, 1

INCERTAE SEDIS

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| PRINTED IN GREAT B

| BY THOMAS DE 1

COMPANY LIMITED |

F i Mis
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REVISION OF BRITISH MARINE
CRETACEOUS OSTRACODA WITH

NGS ON ADDITIONAL FORMS

BY
PETER KAYE, Ph.D.

(Department of Geology, Reading University)

Pp. 35-79 ; 9 Plates

BULLETIN OF
THE BRITISH MUSEUM (NATURAL HISTORY)
GEOLOGY Vol. 10 No. 2
LONDON : 1964

THE BULLETIN OF THE BRITISH MUSEUM
(NATURAL HISTORY), tmstituted im 1949, 1s
issued in five series corresponding to the Departments
of the Museum, and an Historical serves.

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.

This paper is Vol. 10, 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)

Issued December, 1964 Price Two Pounds

Ill.

REVISION OF BRITISH MARINE
CRETACEOUS T@SuRACODA WITT
NOTES ON ADDITIONAL FORMS

By P. KAYE

CONTENTS

INTRODUCTION AND ACKNOWLEDGEMENTS :
STRATIGRAPHICAL POSITION AND LOCATION OF SAMPLES
SYSTEMATIC DESCRIPTIONS
Subfamily Macrocypridinae
Genus Macrocypris Brady
Macrocypris exquisita sp. nov.
Macrocypris muensteriana Jones & Ende
Macrocypris siliqua (Jones)
Macrocypris simplex Chapman
Macrocypris wrighti Jones & Hinde
Subfamily Schulerideinae
Genus Schuleridea Swartz & Seta
Schulevidea jonesiana (Bosquet)
Genus Dolocytheridea Triebel
Dolocytheridea bosquetiana (Jones & Hinde)
Family Progonocytheridae : : 3
Genus Neocythere Mertens
Neocythere (Centrocythere) Appiberiicte Mertens
Neocythere (Physocythere) virginea (Jones)
“Cythere” bairdiana Jones
Family Cytheruridae
Genus Amphicytherura Butler & Jones
Amphicytherura chelodon (Marsson)
Family Brachycytheridae i
Genus Brachycythere Alexander ;
Brachycythere ? sphenoides (Reuss)
Brachycytheve laticristata (Bosquet)
Genus Alatacythere Murray & Hussey
Alatacytheve vobusta (Jones & Hinde)
Alatacythere ads pale?
Family Bythocytheridae :
Genus Monoceratina Roth
Monoceratina acanthoptera (Marsson)
Monoceratina bonnemai sp. nov.
Monoceratina longispina (Bosquet)
Monoceratina montuosa (Jones & Hinde)
Monoceratina pedata pedata (Marsson)
Monoceratina pedata salebrosa (Jones & Hinde)
Monoceratina pedata laevoides Bonnema

On Or wn

On on

38 BRITISH MARINE CRETACEOUS OSTRACODA

Monoceratina sherborni (Jones & Hinde)
Monoceratina tricuspidata (Jones & Hinde)
Monoceratina umbonata (Williamson)
Monoceratina umbonatoides nom. nov.
Family Protocytheridae
Genus Protocythere Triebel
Protocythere consobrina Triebel_.
Protocytheve lineata (Chapman & Sherborn)
Protocythere tricostata Triebel
Protocythere vudispinata (Chapman & Sherborn)
Genus Veenia Butler & Jones : ’
Veenia barringtonensis sp. nov.
Veenia harrisiana (Jones)
Family Trachyleberididae
Genus Cythereis Jones
Cythereis covvigenda nom. nov.
Cythereis folkstonensis nom. nov. .
Cythereis lonsdaleiana Jones
Cythereis macrophthalma (Bosquet)
Cythereis ornatissima s.l. (Reuss) . i
Cythereis ornatissima paupera Jones & Hinde
Cythereis ovnatissima radiata Jones & Hinde
Cythereis luymannae Triebel
Cythereis nuda Jones & Hinde
Cythereis veticulata Jones & Hinde
Cythereis thovenensis Triebel
Genus Platycythereis Triebel . ;
Platycythereis gaultina (Jones)
Platycythereis chapman nom. nov.
Platycythereis laminata Triebel
Genus Tvachyleberidea Bowen
Tvachyleberidea acutiloba (Marsson)
Family Cytherellidae .
Genus Cytherelloidea Newaader :
Cytherelloidea chapmani (Jones & erade)
Cytherelloidea globosa sp. nov. 5
Cytherelloidea gyanulosa (Jones)
Cytherelloidea hindei sp. nov.
Cytherelloidea knaptonensis Kaye . 4
Cytherelloidea oblinquirvugata (Jones & rails)
Cytherelloidea pavawilliamsomana Kaye
Cytherelloidea stricta (Jones & Hinde)
IV. SUMMARY 6 : 5 . : :
V. REFERENCES

SYNOPSIS

The marine Cretaceous Ostracoda figured in Jones (1849), Jones & Hinde (1890), Chapman &
Sherborn (1893) and Chapman (1898) are revised and refigured. Some comparative forms
including five new species are described and illustrated. Four species have been renamed. Of

the 98 specific units considered 55 are retained as valid species.

BRITISH MARINE CRETACEOUS OSTRACODA 39
I. INTRODUCTION AND ACKNOWLEDGEMENTS

THE earliest work on marine British Cretaceous Ostracoda was the description of a
few species by Williamson (1847) in a paper dealing with a variety of micropalaeonto-
logical objects. However, it was not until two years later (Jones 1849) that any
advance was made on this subject. Jones referred most of his species to previously
described forms, particularly those of Roemer (1838, 1840), Reuss (1845, 1846) and
Cornuel (1846, 1848) but many were subsequently proved to be distinct. Later,
Jones (1870) and Jones & Hinde (1890) revised many of the forms and greatly
enlarged the number of species. Papers by Chapman & Sherborn (1893) and
Chapman (1898) on Gault Ostracoda are almost the sum total of early works
additional to that of Jones and it is only recently that papers by Neale (1960, 1962),
on the previously undescribed British basal Cretaceous faunas, have renewed interest
in British marine Cretaceous Ostracoda.

Since the publication of the early works a large number of important articles have
appeared (Alexander 1929, 1933, 1934; Triebel 1938, 1938a, 1940, 1941 ; Deroo
1956 ; Mertens 1956 ; Oertli 1958) which have fundamentally altered the taxonomic
concepts of Cretaceous Ostracoda and consequently Jones’ and other material has
been urgently in need of revision for some time. The poor figures of many of the
species have made some of them unusable in the practical sense and the complete
lack of designation of type specimens has left interpretation in all cases difficult.
Certain of the species have been used, often without reference to the original
specimens, as the type members for higher taxonomic units and in some cases well
known species that have been perpetuated without reference to the original material
now need renaming.

The present work is an attempt to refigure and redescribe as many of the original
species as possible and interpret them within the existing classification. Descriptions
of certain new and comparative forms are included where necessary and particular
attention has been paid to relating more recent work to the early groupings. The
museum registration numbers of all the revised material are included together with
details of additional comparative material placed by the writer in the British Museum
(Natural History) collections.

Most of the redescribed specimens are in the British Museum (Natural History)
where the material figured by Jones (1849) and Jones & Hinde (1890) is to be found.
Also in the Museum is the material described by Chapman & Sherborn (1893) and
Bonnema’s material from the Chalk of Limburg. Valuable comparative material
was found in the British Museum collections of Morris, Gamble, Vine, Mockler, Lang,
Metcalfe and Rowe whilst further specimens attributed to Chapman were examined
in the collection of the Geological Survey & Museum. The material from Chapman
(1894) Bargate Beds and Chapman (1898) Cambridge Greensand is in the Sedgwick
Museum at Cambridge. Further comparative material was obtained from the
writer’s extensive collection of British Cretaceous material and by the sampling of
topotypic horizons. In addition, various workers in Western Europe and North
America have been kind enough to furnish the writer with specimens and washed
residues from a variety of Cretaceous formations,

40 BRITISH MARINE CRETACEOUS OSTRACODA

In certain cases the original figured material can no longer be traced and in other
cases there is no available material at all so that it is impossible to refigure all of the
early species. Most prominent of the omissions are several species described by
Jones & Hinde (1890) and material referable to this work is on the whole rather
limited. This can partly be explained by the fact that many of the figures are
reproductions from the 1849 plates and that some of the specimens refigured were
loaned to Jones by other workers, e.g. Chapman. It is most unfortunate that this
shortage of material should correspond with the poor quality illustrations, the
collection from the comparatively well figured 1849 monograph being preserved
almost intact.

Many of Jones & Hinde’s species falling within the superfamily Cypridacea from
the Chalk formation have not been included as the writer is reluctant to interpret
species based on a single specimen before a thorough study of the ostracod populations
of the Chalk has been undertaken. The limits and validity of the various species
can only be decided upon after consideration of such a project the scope of which is
outside the limits of this present work.

Only valid references have been included in the synonymies of species described
in this paper. This study has been carried out during the tenure of a D.S.LR.
Research Fellowship at the Sedimentology Laboratory, Department of Geology,
Reading, and I am extremely grateful to Professor P. Allen for all his help and
encouragement. I would also like to express my gratitude to the Trustees of the
British Museum (Natural History) and to the Authorities at the Sedgwick Museum
(Cambridge) for the loan of much of the type material in their care and also to
Dr. R. H. Bate of the British Museum (Natural History) and Dr. F. W. Anderson,
Chief Palaeontologist at the Geological Survey for their help and criticism and for
providing facilities for study at their respective establishments.

My gratitude is also due to many of my friends at Reading, particularly Dr. R.
Goldring, for discussion and criticism of the manuscript, Mr. D. B. Williams for
discussion and help in field work and Mr. J. L. Watkins for the photography.

I further acknowledge Dr. E. A. Butler of Louisiana Geological Survey, Professor
H. V. Howe of Louisiana State University, Dr. H. J. Oertli of Société Nationale des
Petroles D’Aquitane, Dr. E. Triebel and Dr. H. Malz of the Senckenberg Museum,
Frankfurt am Main and Dr. E. Herrig of Ernst Morritz Arndt Universitat,
Griefswald for the comparative material they have kindly sent to me, and to many
other authors for the offprints of their various articles, without which this study
would have been impossible.

Il. STRATIGRAPHIC POSITION AND LOCATION OF SAMPLES

Almost all the specimens figured by the earlier workers came from horizons now
considered to be Upper Cretaceous ; the only pre-Albian references being Chapman’s
paper (1894) on the Aptian Bargate beds of Surrey and a few forms recorded by
Jones from the Aptian sponge gravels at Faringdon, Berkshire. The Bargate beds
material, the subject of a further paper (Kaye 1964) is not considered further here.

Chapman concentrated on Ostracoda from the Gault Clay (Middle and Upper
Albian) whilst Jones’ material came from the Gault Clay and the Chalk. Many of

BRITISH MARINE CRETACEOUS OSTRACODA 41

Jones’ Chalk localities are somewhat uncertain as to horizon. The major localities
from which ostracoda were described by these early workers are listed below :

JONES 1849.
(A) ApTiaAN Sponge gravels at Faringdon, Berks.

(B) ALBIAN (2) Gault Clay at Folkestone, Kent.

(77) Gault Clay at Leacon Hill, Kent.

(17) Red Chalk at Speeton, E. Yorks.

(v) | Upper Greensand at Warminster, Wilts.
(C). -CHark (

(

1) Chalk Detritus (Mainly Cenomanian) at Charing, Kent.

7) Chalk marl and Grey Chalk from Dover, Kent
(S. varians).

(7) Chalk at Gravesend, Kent.

(tv Upper Chalk at Norwich (B. mucronata).

(v Chalk at Charlton, London.

JONES & HINDE 1890. Additional localities.
(A) CHALK 1) Upper Chalk at Thorpe, Norwich, Norfolk
(B. mucronata).
(7) Flint meal, Upper Chalk at Horstead, Norfolk
(B. mucronata).
(4a) Flint meal, Upper Chalk of Antrim, various localities—
(B. mucronata).
(a) Black Hill near Hannahstown, (b) Ballytober,
Isle of Magee, (c) Whiteabbey, (d) Maghera-
morne, (e) Gobbins, (f) Glenarm.
(‘v) Flint meal, Upper Chalk at Keady Hill. Londonderry
(B. mucronata).
(v) Chalk rock of Bedfordshire, Buckinghamshire and
Oxfordshire (H. planus).
(vi) Chalk rock at Dunstable, Bedfordshire (H. planus).
(vit) Chalk marl at Didcot Station, Berkshire (S. varzans).
(B) ALBIAN (2 Gault Clay at Godstone, Surrey.
(iz) Gault Clay in Meux’s Well, London.
(«1t) Upper Greensand, Ventnor, Isle of Wight.

CHAPMAN & SHERBORN 1893. All from the Gault Clay at Folkestone, Kent.
CHAPMAN 1898. All from the Cambridge Greensand at Swaffham, Cambridge.

mo naOk Ss LOCALITIES.
(A) APTIAN (:) Speeton Clay at Speeton E. Yorks. (P. bodei subzone)
Grid Ref. TA150758.
(1) Sponge gravel at Coxwell Pit, Faringdon, Berks.
(P. nutfieldensis subzone) Grid Ref. SU288943.
(771) Bargate beds at the mortuary pit Compton near Guild-
ford (P. nutfieldensis subzone) Grid Ref. SU962481.

42 BRITISH MARINE CRETACEOUS OSTRACODA

(‘v) Upper Crioceras Beds in Chale Bay, Isle of Wight

(C. debile subzone). Grid Ref. SZ473780.
(B) ALBIAN (2) Gault Clay (Middle Albian) at Speeton, E. Yorks.

(77) Red Chalk (Upper Albian) at Speeton, E. Yorks.

(171) Lower Gault at Culham near Abingdon, Berks. Grid Ref.
SU510949.

(‘v) | Lower and Upper Gault in the British Portland Cement
Co’s. pit at Small Dole near Henfield, Sussex. Grid
Ref. TV218131.

(v) Upper Gault in the Rugby Portland Cement Co’s. pit at
Paddlesworth, near Maidstone, Kent. Grid Ref.
TQ695623.

(vt) Upper Gault in Fisons Brick pit at Burwell, Cambs.
Grid Ref. TL516601.

(viz) Upper Gault and Cambridge Greensand in Messrs.
Eastwoods Cement pit at Barrington, Cambs. Grid
Ref. TL394507.

(vii?) Lower and Upper Gault in Mundays Hill pit at Leighton
Buzzard, Beds. Grid Ref. TL915978.

(77) Flint meal, Sonning, Berks. (MM. coranguinum Zone).

Grid Ref. SU750778.
III. SYSTEMATIC DESCRIPTIONS
Order PODOCOPIDA
Sub order PODOCOPINA
Superfamily BAIRDIACEA
Family MACROCYPRIDIDAE
Genus MACROCYPRIS Brady 1867

Macrocypris exquisita sp. nov.
(Pl. 4, figs. 12, 16)

DERIVATION OF NAME. exquisita ; referring to the excellent preservation of the
type material.

Diacnosis. Macrocypris, with strongly acuminate posterior. Ventral margin
slightly convex, greatest height just anterior to mid-length.

Horotypre. A right valve, B.M.N.H., Io. 1270, from the Upper Gault at Burwell,
Cambs.

PARATYPES. Four specimens from the same horizon and locality, B.M.N.H.,
Io. 1271-74.

MEASUREMENTS. Length Height

Right Valve (B.M.N.H., Io. 1270, holotype) 1-54 mm. 0-52 mm.

DESCRIPTION. Carapace large and elongate. Greatest height at two-fifths
length, greatest width at mid-length, Posterior end strongly acuminate. Dorsal

BRITISH MARINE CRETACEOUS OSTRACODA 43

margin arched, ventral margin weakly convex in its central portion in the right
valves but straight or slightly concave in front of mid length in the left valves.
Lateral surface smooth. Right valve larger than left overlapping strongly dorsally
and ventrally. Duplicature broad, large vestibules occurring both anteriorly and
posteriorly. Radial pore canals short and numerous, normal pore canals large but
few in number, well scattered. The muscle group consists of a central rosette of
scars, upper half of rosette formed of a row of 3 large scars in contact, lower half
formed of a row of four smaller scars in contact. A group of two small scars lies
antero-dorsal to the main rosette. The hinge is complex being composed in the right
valve of two short terminal smooth ridges separated by a long narrow shelf within
the margin. This shelf is deeper at its ends and in its central portion is strongly
overhung by a long, high, smooth bar.

REMARKS. M. exquisita is very closely related to M. siliqua. The principal
difference is the lower degree of arching of the dorsal margin in the former causing
the posterior end to be more strongly acuminate.

Macrocypris muensteriana Jones & Hinde
(Pl. 4, figs. 9, 10)
1849 Bairdia siliqua var. « Jones : 25, pl. 5, figs. 16e—-g.
1870 Macrocypris ? avcuata (Munster) ; Jones : 75, 77.
1890 Macrocypris muensteriana Jones & Hinde : fo, pl. 2, figs. 45-47.

Diacnosis. Macrocypris with short ventral margin and strongly arched dorsal

margin. Height/Length ratio small for the genus.

LectotypPe. B.M.N.H., In. 51622, figured Jones (1849, pl. 5, figs. 16f, g) from

the Detritus at Charing, here designated.

PARALECTOTYPE. B.M.N.H., In. 51618, figured Jones (1849, pl. 5, fig. 16e) from

the same locality.

MEASUREMENTS. Length Height
Carapace (B.M.N.H., In. 51622, lectotype) . 1:07 mm. 0-48 mm.
Carapace (B.M.N.H., In. 51618, paralectotype) 1-05 mm. 0-48 mm.

REMARKS. This species grouped at first with M. siliqua was erected as a distinct

species by Jones & Hinde (1890). It differs from the aforementioned form in its
shorter length and proportionally greater height. The posterior end is less drawn
out and the dorsal margin is more strongly convex. The greatest height is just
posterior to mid-length.

Macrocypris siliqua (Jones)
(BIA, fies cee 15,618)
1849 Cythere (Bairdia) siliqua Jones : 25, pl. 5, figs. 16a—d (non figs. 16e—h).
1870 Macrocypris siliqua (Jones) Jones : 75, 77.
1890 Macrocypris siliqua (Jones) ; Jones & Hinde : 9, pl. 2, figs. 38-41.
21898 Macrocypris siliqua (Jones) ; Chapman : 333.
DiacGnosis. Macrocypris with greater height at mid-length. Dorsal margin
evenly arched, posterior margin drawn out to form an acute point.

44 BRITISH MARINE CRETACEOUS OSTRACODA

LecroTyPE. B.M.N.H., In. 51617, figured Jones (1849, pl. 5, fig. 16a) from the
Detritus at Charing, here designated.

PARALECTOTYPES. B.M.N.H., In. 51619-20, figured Jones (1849, pl. 5, figs.
16c, d) from the Chalk at Gravesend.

OTHER MATERIALS. (i) Two specimens (B.M.N.H., Io. 1593-94) from the Upper
Chalk, Keady Hill, N. Ireland (Jones & Hinde 1890). (11) Two specimens
(B.M.N.H., lo. 1276) from Sonning, Berkshire.

MEASUREMENTS. Length Height
Carapace (B.M.N.H., In. 51617, lectotype) . I-70 mm. 0-57 mm.
Right valve (B.M.N.H., Io. 1594) ‘ 22-22) mm: 0-75 mm.
Right valve (B.M.N.H., Io. 1276) : . 1:60 mm. 0-62 mm.
Left valve (B.M.N.H., Io. 1276) : 1°58 mm. 0-55 mm.

REMARKS. Macrocypris siliqua differs from ne other members of this genus
found in the English Chalk in having the greatest height at mid-length rather than
at one-third length as in M. simplex or at two-thirds length as in M. wrightti. The
ventral margin is straight or slightly convex in the larger right valves but is slightly
incurved antero-ventrally in the left valves. This incurving of the margin is absent
in M. simplex but is more prominent in M. wrighti1. These differences may reflect
the phylogeny of the genus and form an evolutionary sequence throughout the
British Cretaceous but the differences in size of the type material of the three species
may indicate an ontogenetic relationship. A statistical study of a large quantity of
material from a wide range of horizons and localities is required before the true
relationships of the three species can be determined.

Macrocypris simplex Chapman
(Pl. 4, fig. 13)
1898 Macrocypris simplex Chapman : 333, text-figs. Ia—c.
HoLotyPeE. Sedgwick Museum No. B40618, Cambridge Greensand ; Swaffham.
OTHER MATERIAL. One specimen (B.M.N.H., Io. 1275) from the Red Chalk at
South Cave, E. Yorks.

MEASUREMENTS. Length Height
Carapace (B40618, holotype) .. $ 35 mam: 0-46 mm.
Left valve (B.M.N.H., Io. 1275) . I-I5.mm. 0-40 mm.

REMARKS. The nolomrae is rather badly, preserved but shows significant
differences from M. siliqua. The carapace is more elongated and tapers more
strongly posteriorly. The ventral margin is straight ; the greatest height is at
one-third length. Macrocypris concinna Jones & Hinde may be conspecific with
this form but no figured material is available.

Macrocypris wrighti Jones & Hinde
(PIS Ay fies 17)
1890 Macrocypris wrightii Jones & Hinde : 10, pl. 2, figs. 42, 44.
DiaGnosis. A large elongate Macrocypris with greatest height at two-thirds
length. There is a convexity of the ventral margin anteriorly in the right valve.

BRITISH MARINE CRETACEOUS OSTRACODA 45

Lectotype. B.M.N.H., Io. 1595, figured Jones & Hinde (1890, pl. 2, fig. 44)
from the Upper Chalk of Magee, Antrim, N. Ireland, here designated.
PARALECTOTYPE. B.M.N.H., I. 2473. A broken right valve from the same
locality.
MEASUREMENTS. Length Height
Left valve (B.M.N.H., Io. 1595, lectotype) . 2-46 mm. 0-75 mm.
Right valve (B.M.N.H., I. 2473, paralectotype) broken 0-92 mm.
REMARKS. This species is much more elongated than the other species of this
genus found in the Cretaceous. Apart from size it differs from M. siliqua in having
the greatest height set further back (at two-thirds length) and in being more strongly
drawn out anteriorly. As there is only one complete specimen, and this being the
smaller valve the true nature of the species is still somewhat in doubt.

Superfamily CYTHERACEA
Family CYTHERIDEIDAE
Genus SCHULERIDEA Swartz & Swain 1946

Schuleridea jonesiana (Bosquet)
(Pl. 1, figs. 1-5)

1849 Cythere hilseana (Roemer) ; Jones : 10, pl. 1, figs. 1a—g.
1852 Cytheridea jonesiana Bosquet : 38.
1870 Cytheridea perforata (Roemer) ; Jones : 74.
1890 Cytheridea perforata (Roemer) ; Jones & Hinde : 29, pl. 1, figs. 1-4.
1893 Cytheridea perforata (Roemer) ; Chapman & Sherborn : 349.
1893 Cytheridea perforata insignis Chapman & Sherborn : 349, pl. 14, fig. 10.
1893 Cytheridea votundata Chapman & Sherborn : 349, pl. 14, fig. Ir.
1893 Cythere ? spinifera Chapman & Sherborn’: 348, pl. 14, fig. 3.
1938 Cytheridea (Haplocytheridea) jonesiana Bosquet ; Triebel : 480, pl. 2, figs. 21-25.
?1954 Haplocytheridea jonesiana (Bosquet) ; Stchépinsky, pl. 2, figs. 13, 14.
1956 Schulevidea jonesiana (Bosquet) Mertens : 193, pl. 10, figs. 38-40.
1956 Schuleridea jonesiana (Bosquet) ; Deroo : 1512, pl. 2, figs. 26-31.
1958 Schulevidea jonesiana (Bosquet) ; Oertli : 1507, pl. 5, figs. 105-113.
1963b Schuleridea jonesiana (Bosquet) ; Kaye : 31, pl. 2, figs. 9-13.

DiaGnosis. Large Schuleridea with strongly pitted surface. Eye tubercle
prominent, sexual dimorphism well marked. Median hinge groove in left valve
often overhung by the strong bar dorsal of it.

LecToTyPE. B.M.N.H., In. 51637, figured Jones (1849, pl. 1, fig. 1d), from the
Gault Clay at Folkestone, here designated.

PARALECTOTYPES. B.M.N.H., In. 51634, 36, 38, 39, 40, figured Jones (1849,
pl. 5, figs. 1a—c, e-g) from the Detritus at Charing (1a, 6, f, g) and the Gault at
Folkestone (rc, e).

OTHER MATERIAL. (1) B.M.N.H., Io. 347, from the Chalk marl at Didcot (Jones
& Hinde 1890). (ii) B.M.N.H., I. 2708, Gault Clay, Folkestone (Chapman &
Sherborn 1893, pl. 14, fig. 10, C. perforata var. insignis). (iii) B.M.N.H., I. 2709,
Gault Clay, Folkestone (Chapman & Sherborn 1893, pl. 14, fig. 11, Cytheridea
volundata). (iv) Sedgwick Museum B.4o0601, 2, Cambridge Greensand, Swaffham
(Chapman 1898). (v) B.M.N.H., Io. 308, Detritus, Charing (Morris collection).
(vi) B.M.N.H., lo. 1207, Lower Gault, Culham, Oxon.

46 BRITISH MARINE CRETACEOUS OSTRACODA

MEASUREMENTS. Length Height
Female Left Valve (B.M.N.H., In. 51634) . 0-84 mm. 0-58 mm.
Male Left valve (B.M.N.H., In. 51637,

lectotype) ; ; ; : . 0°92 mm. 0-60 mm.
Male left valve (B.M.N.H., I. 2708) . 2) L-00mmm: 0-58 mm.
Female left valve (B.M.N.H., I. 2709) . 0-85 mm. 0-62 mm.

REMARKS. This characteristic species was originally included by Jones within
the Hauterivian form Dolocytheridea lilseana (Roemer). Bosquet (1852) realised
the differences in shape and hingement between the two species and renamed Jones’
form Cytheridea jonesiana. Jones (1870, 1890), though agreeing with Bosquet that
it was not C. hilseana Roemer equated his form with another of Roemer’s species
Cytherina perforata. This Tertiary species is undoubtedly specifically distinct from
Jones’ form and Bosquet’s interpretation of the latter is now followed. Chapman &
Sherborn (1893) erected further species, which are now considered to be conspecific
with Bosquet’s species. The form figured as Cytheridea perforata var. insignis is a
male left valve, whilst the holotype of Cytheridea rotundata is a female left valve.
The form figured and described by Chapman & Sherborn (1893) as Cythere ? spintfera
is an instar of Schuleridea jonesiana.

The species has been adequately described but no type specimen or type horizon
has ever been designated.

Genus DOLOCYTHERIDEA Triebel 1938
Dolocytheridea bosquetiana (Jones & Hinde)
(Pl. 1, figs. 18-20)

1849 Bairdia angusta (Munster) ; Jones : 26, pl. 6, figs. 18a-f.

1890 Pontocypris bosquetiana Jones & Hinde : 4, pl. 2, figs. 65, pl. 4, fig. 3.

1890 Pontocypris triquetva Jones ; Jones & Hinde : 4, pl. 3, figs. 35-37.

1890 Bythocypris veussiana Jones & Hinde : 12, pl. 2, figs. 56, 61-63.

1893 Pontocypris bosquetiana Jones & Hinde ; Chapman & Sherborn : 346.

1898 Pontocypris bosquetiana Jones & Hinde ; Chapman : 332.

1938 Cytheridea (Dolocythevidea) bosquetiana (Jones & Hinde) Triebel: 498, pl. 5, figs. 80-83,
pl. 6, fig. or.

1956 Dolocytheridea bosquetiana (Jones & Hinde) ; Mertens : 196, pl. Ito, figs. 45-47.

1956 Dolocytheridea bosquetiana (Jones & Hinde) ; Deroo : 151.

1958 Dolocytheridea bosquetiana (Jones & Hinde) ; Oertli: pl. 4, figs. 85, 86.

DiaGnosis. Dolocytheridea with straight ventral margin and convex dorsal
margin. Greatest height one-quarter to one-third length. Hinge simple, without
terminal teeth or crenulations.

LrEcToTyPE. B.M.N.H., In. 51629, figured Jones (1849, pl. 6, fig. 184). Gault,
Folkestone, here designated.

PARALECTOTYPES. B.M.N.H., In. 51628, In. 51630-31, figured Jones (1840,
pl. 6, figs. 18d, c, f), Gault, Folkestone.

OTHER MATERIAL. (i) B.M.N.H., I. 2457 and Io. 1566, figured Jones & Hinde
(1890, pl. 3, figs. 35-37 as Pontocypris triquetra), Detritus, Charing, Kent. (ii)
B.M.N.H., I. 2696, (Chapman & Sherborn, 1893 Pontocypris bosquetiana) ; B.M.N.H.,
I. 2692-93 (Chapman & Sherborn 1893, Bythocypris silicula and var. minor) ;

BRITISH MARINE CRETACEOUS OSTRACODA 47

B.M.N.H., I. 2710 (Chapman & Sherborn 1893, Pseudocythere simplex). All from
the Gault at Folkestone. (iv) Sedgwick Museum B.40566 (Chapman 18098),
Cambridge Greensand, Swaffham. (v) B.M.N.H., Io. 1277, lo. 1565. Six specimens
(one figured) from the Upper Gault, Maidstone, Kent.

MEASUREMENTS. Length Height
Carapace (B.M.N.H., In. 51629, lectotype) . 0-77 mm. 0°37 mm.
Carapace (B.M.N.H., Io. 1565) . : . 0-775 mm. 0:37 mm.
Left valve (B.M.N.H., I. 2696) . d . 0779 mm. 0-42 mm.

REMARKS. This species has been well described in the past decade but no
lectotype has ever been erected. Early authors have confused this species with
Pontocyprella harrisiana (Jones) which occurs at the same horizon. The latter
species has been refigured by Neale (1962) and is consequently not referred to here.

Family PROGONOCYTHERIDAE
Genus NEOCYTHERE Mertens 1956
Neocythere (Centrocythere) denticulata Mertens
(Bier stigss S512, 13)

1849 Cytheve punctatula (Roemer) ; Jones : 11, pl. I, figs. 2c—m (non figs. 2a, b).
1870 Cytheropteron concentyicum (Reuss) Jones : 74, 76.

1890 Cytheropteron concentricum (Reuss) ; Jones & Hinde : 31, pl. 1, figs. 5, 6, 8-10.
1893 Cytheropteron concentricum (Reuss) ; Chapman & Sherborn : 347.

1956 Centrocythere denticulata Mertens : 204, pl. 11, figs. 66-71, pl. 14, figs. 97-99.
1963 Neocythere (Centrocythere) denticulata Mertens, Kaye : 280, pl. 41, fig. 13.

MaTERIAL. (i) B.M.N.H., In. 51644-55, figured Jones (1849, pl. 1, figs. 2c—m)
all except figs. 27, 7, J, from the Gault Clay at Folkestone the latter three being from
the Detritus at Charing (22, 1) and from the Upper Greensand at Warminster
respectively. (ii) B.M.N.H., Io. 1185. Six specimens from the Lower Gault of
Culham, Oxfordshire.

MEASUREMENTS. Length Height
Left valve, In. 51649 : : : =) 0-68: 0-43 mm.
Right valve, In. 51656 : 5 : . 0-68 mm. 0-42 mm.

REMARKS. Jones described and figured (1849, pl. 1, figs. 2a—m) specimens from
the British Albian and Cenomanian as Cythere punctatula (Roemer). Subsequent
correspondence with Bosquet caused Jones (1870) to place his specimens within
Cytherina concentrica Reuss (1846). Almost all small ovate Cretaceous species with
a concentric ornament were identified by early authors as Cytherina concentrica
Reuss although the generic allocation varied considerably. Recent work by
Mertens (1956) on Reuss’ type material has shown that the specimens though too
poorly preserved to be adequately described and classified are found to occur in the
Turonian. Jones’ specimens belong to species erected by Mertens for forms
occurring lower in the Cretaceous. The specimens from the Albian (Gault) nearly
all belong to Neocythere (Centrocythere) denticulata Mertens whilst those from the
basal Cenomanian (Charing) can be referred largely to Neocythere (N.) vanveent
Mertens. The specimens described by Jones (1849) as Cytheropteron punctatula
var. virginea belong to a distinct species.

48 BRITISH MARINE CRETACEOUS OSTRACODA

Neocythere (Physocythere) virginea (Jones)
(Pl. 1, figs. 11, 14-17)

1849 Cythere punctatula var. virginea. Jones : 12, pl. I, fig. 2n.

?1852 Cythere punctatula var. virginea. Jones ; Bosquet : 73, 74, pl. 3, figs. 10a—d.
1890 Cythere concentrica var. virginea. Jones & Hinde : 32, 33, pl. 1, figs. 14-17.
1938 Cythere slavantensis Veen : 2, pl. 1, figs. 9-15.

1940 Cythere slavantensis Veen ; Bonnema : 129, pl. 4, figs. 1-4.

21956 Procytheropteron virgineum (Jones) Mandelstam : 131, text-figs. qa, b.

DraGnosis. Neocythere with poorly developed concentric ornament, the dorso-
lateral surface being smooth. Hinge strong, crenulate merodont with a marginal
shelf in the left valves.

LecToTyPE. B.M.N.H., In. 51656. A juvenile carapace figured Jones (1849,
pl. 1, fig. 27) from the Chalk at Gravesend.

OTHER MATERIAL. (i) B.M.N.H., I. 2489, Io. 1562 (Jones & Hinde 1890) from
Magheramorne, N. Ireland and B.M.N.H., Io. 378 (Jones & Hinde 1890) from Keady
Hill. (ii) B.M.N.H., In. 53170-71, In. 53096, In. 53256, Io. 1563-64; (Rowe)
from the Upper Chalk at Norwich. (iii) B.M.N.H., Io. 1181 from the Upper Chalk
coranguinum Zone, Sonning.

MEASUREMENTS. Length Height
Carapace (B.M.N.H., In. 51656, lectotype) . 0-54 mm. 0-32 mm.
Juvenile left valve (B.M.N.H., Io. 378) 4 20-53. 0-32 mm.
Juvenile left valve (B.M.N.H., Io. 378) . 0-55 mm. 0-34 mm.
Left valve (B.M.N.H., I. 2489) . ‘ . 0°64 mm. 0-45 mm.
Left valve (B.M.N.H., I..2489) . ; + 0-70omm, 0-50 mm.
Left valve (B.M.N.H., Io. 1562) : . 0°83 mm. 0-45 mm.
Rowe collection, Norwich (16 specimens) 0-70-82 mm. 0-46-53 mm.
Veen (1938) . ‘ ; . 0-80 mm. —

DESCRIPTION. Valves ovate, strongly tumid ventrally. Dorsal margin strongly
arched, without cardinal angles. Ventral margin convex but obscured in lateral
view. Lateral surface basically smooth but with faint concentric ribs appearing
antero-ventrally, postero-ventrally and on the ventral surfacein the adults. Greatest
height just anterior to mid-length, greatest width just posterior to mid-length.
Duplicature narrow crossed by a small number (15 anteriorly) of thick straight
radial pore canals. A small crescentic vestibule occurs anteriorly. Normal pore
canals abundant, arranged concentrically. Hinge strong, crenulate merodont ;
consisting in right valve of terminal denticulate teeth separated by a locellate groove.
In the left valve there are two divided sockets separated by a strong denticulate bar.
Above the median element is a broad shallow depressed shelf.

REMARKS. The instar figured by Jones is conspecific with larger specimens
figured by Veen (1938) and Bonnema (1940) as Cythere slavantensis. Specimens of
this species reported from the Aptian, Albian and Cenomanian are worn species of
Neocythere (N.) vanveeni and other related forms.

The degree of ornamentation appears to be variable as forms with slightly more
pronounced concentric ribbing have been found by the writer from flint meal of
Micraster coranguinum age from Sonning, Berkshire. The measurements of the

BRITISH MARINE CRETACEOUS OSTRACODA 49

British specimens agree well with Veen ; Jones’ original specimen being a juvenile.

“Cythere” bairdiana Jones
(Rips ti es1Q)

1849 Cythere baivdiana Jones : 13, pl. 2, figs. 5a-c.
1870 Cythere baivdiana Jones ; Jones : 74.
1890 Cythere baivdiana Jones ; Jones & Hinde : 15, pl. 1, figs. 30-32.

MATERIAL. A single right valve, B.M.N.H., In. 51633, from the Lower Greensand
(Aptian) of Faringdon.

MEASUREMENTS. Length Height

Right valve (B.M.N.H., In. 51633) . . 063 mm. 0-35 mm.

REMARKS. This species is represented by a single very worn right valve from the
Faringdon Greensand. The shape, pitted ornament and amphidont hinge suggests
that it is a species of Macrodentina s.1. Derivation from Upper Jurassic sediments is
possible but other comparable specimens have been found in equivalent strata
(Bargate Beds) near Guildford (Kaye 1964).

Family CYTHERURIDAE
Genus AMPHICYTHERURA Butler & Jones 1957

Amphicytherura chelodon (Marsson)
(Pla fies: 6.7)

1849 Cythere (Cythereis) macrophthalma (Bosquet) ; Jones : 17, pl. 2, figs. 8a—b.
1870 Cytheve macrophthalma (Bosquet) ; Jones : 75, 76.

1880 Cythere chelodon Marsson : 43, pl. 3, figs. 13a-f.

1890 Cythereis icenica Jones & Hinde : 26, pl. 1, figs. 37-39.

1958 Amphicytheruva chelodon (Marsson) Howe & Laurencich : 46.

1958 Amphicytherura icenica (Jones & Hinde) Howe & Laurencich : 48.

MATERIAL. B.M.N.H., Io. 1560-61, Io. 1208 from the uppermost Chalk at
Norwich.

MEASUREMENTS. Length Height

Left valve (B.M.N.H., Io. 1560) : . 053 mm. 0°33 mm.

REMARKS. Jones records only two specimens of this species, which have since
been lost. He does, however, remark on the similarity of his specimens and those
of Marsson. The figures and redescription of Marsson’s form in Howe & Laurencich
(1958) fit these specimens and Jones’ figures well and therefore all are assumed to be
conspecific.

The hinge is strongly amphidont with divided terminal elements. The ornament
of three longitudinal ribs with subsidiary cross ribs fit the description exactly.

There is no trace of the specimens described by Jones & Hinde (1890) as Cythereis
icenica quadrata but from their figures the specimens look to be of a young stage of a
species of Cythereis, possibly akin to Cytherets semiplicata (Reuss). Until additional
material can be found no further progress can be made.

50 BRITISH MARINE CRETACEOUS OSTRACODA

Family BRACHYCYTHERIDAE
Genus BRACHYCYTHERE Alexander 1933

Brachycythere cf. sphenoides (Reuss)
(Plate 2, fig. 5)

21854 Cytheve sphenoides Reuss : 141, pl. 27, figs. 2a—c.
1890 Cytheropteron sphenoides (Reuss) Jones & Hinde : 33, 34, pl. 1, figs. 18-20.

MATERIAL. B.M.N.H., Io. 1575. A right valve, presumably the one figured by
Jones & Hinde (1890) from the Chalk Rock at Dunstable.

MEASUREMENTS. Length Height Width

Right valve (B.M.N.H., Io. 1575) . o80mm. 047mm. 0:27 mm.

Remarks. This single specimen is compared to Brachycythere sphenoides Reuss
on a basis of similarity to the published figures and on Jones & Hinde’s identification.
The valve is smooth and swollen ventrally. The ventral rib though directed
posteriorly is not drawn out to form an ala. The eye tubercle is particularly
prominent. The hinge is strongly amphidont having a high smooth anterior tooth
and an elongate divided posterior tooth in the right valve. As there is only a right
valve the details of an accommodation groove are lacking.

The species resembles Brachycythere laticristata (Bosquet), which is found at
somewhat higher horizons, but has the ventral rib less drawn out posteriorly and
the long margins more strongly convergent.

Brachycythere laticristata (Bosquet)
(Pl. 2, figs. 1-4, 6)

1854 Cythere laticristata Bosquet : 118, pl. 7, figs. 11a—d.
1940 Brachycythere laticristata (Bosquet) Bonnema : 129, pl. 4, figs. 5-7.
MaTeERIAL. B.M.N.H., In. 53142, 53249-54, lo. 1567-71. Several specimens in
slides from the Rowe collection, Upper Chalk, Norwich.
MEASUREMENTS Length Height Width
Left valve (B.M.N.H., Io. 1569) 0-95 mm. 0-60 mm. 0.37 mm.

DEscRIPTION. Valves smooth and inflated ; strongly tumid ventrally but not
alate. The ventral rib is strongly drawn out posteriorly and has a small laterally
directed spine on its crest. Eye tubercle prominent ; lower half of anterior and
posterior margins dentate. A weak longitudinal ridge occurs on the ventral surface.
Duplicature broad, crossed by numerous radial pore canals which show a tendency
to branch antero-ventrally. Hinge strongly amphidont ; in the right valve a high
smooth anterior tooth with a small anterior extension and an elongate divided
posterior tooth (6 denticles) ; median element of the left valve with a marked
accommodation groove above it.

Remarks. This species is rather similar to B. sphenoides but is more inflated and
has the ventral rib more strongly drawn out posteriorly. The long margins are
not as strongly convergent.

BRITISH MARINE CRETACEOUS OSTRACODA 51
Genus ALATACYTHERE Murray & Hussy 1942

Alatacythere robusta (Jones & Hinde)
(Pl. 2, figs. 7-16, 18)

1849 Cythereis alata (Bosquet) ; Jones : 21, pl. 5, figs. r4a—d.
1890 Cytheropteron alatum vobustum Jones & Hinde : 36, pl. 2, figs. 24-27
1890 Cytheropteron alatum fortis Jones & Hinde : 36, pl. 2, figs. 20, 21.
?1890 Cytheropteron alatum cornuta Jones & Hinde : 36, pl. 4, fig. 36.
?1890 Cytheropteron hibernicum Jones & Hinde : 36, pl. 6, figs. 22, 23.
1893 Cytheropteron alatum cornuta Jones & Hinde ; Chapman & Sherborn : 347.

MATERIAL. (i) B.M.N.H., In. 51689-90, figured Jones (1849, pl. 5, figs. 14a, 0)
from the Upper Chalk, Norwich. (ii) B.M.N.H., Io. 362, Io. 1576 from Dunstable,
I. 2458 from Kent, I. 2480 from Gobbins (all Jones & Hinde 1890, var. vobustum),
Upper Chalk. (iii) B.M.N.H., Io. 1577-78 from Keady Hill, I. 2481 from Magee
(Jones & Hinde 1890, var. fortis), Upper Chalk. (iv) B.M.N.H., Io.2207 from
between Black Head and Gobbins, I. 2476 from Keady Hill (Jones & Hinde
1890), Upper Chalk. (v) B.M.N.H., I. 2678 (Chapman & Sherborn 1893), Gault,
Folkestone. (vi) B.M.N.H., In. 53172, In. 53249-54, Io. 1572-74 (Rowe) Upper
Chalk, Norwich.

MEASUREMENTS. Length Height
Jones’, Rowe’s specimens . ‘ 0:76-0:80 mm. 0:44-0:52 mm.
BM ON, I. 2678 tj : : : I-00 mm. 0-58 mm.
BeMONJ., In. 53172 ; : 0-88 mm. 0-52 mm.

REMARKS. The available specimens of this species show that there is an inter-
gradation between most of Jones & Hinde’s varieties. There appear to be no
representatives among their specimens showing the large size indicated for many
of the varieties, the form from the Gault clay (Chapman collection) being the only
large individual found. The bulk of the forms seem to approximate to var. robusta
in size and consequently that name is taken for the species. The degree of inflation,
the size and shape of the ala, the arching of the dorsal margin and the denticulation
of the anterior and posterior margins is extremely variable ; all intermediates
being seen to occur. A thorough statistical study of a large number of specimens
may, however, enable the species to be subdivided.

The species is referred to the genus Alatacythere on the basis of its amphidont
hinge ; the posterior tooth in the right valve being elongate and divided ; there is
no accommodation groove in the left valve.

Alatacythere ? phylloptera (Bosquet)
(Bi 2, figse 27, £0)
21854 Cythere phylloptera Bosquet : 116, pl. 7, figs. 1oa—d.
1890 Cytheropteron ? phyllopterum (Bosquet) Jones & Hinde : 37, pl. 3, figs. 9, Io.
1940 Cythereis (Pterygocythereis) phylloptera (Bosquet) Bonnema : 132, pl. 4, figs. 37-41.
MATERIAL. B.M.N.H., lo. 377, Io. 1579-80, four specimens from the Jones &
Hinde collection labelled Cytheropteron sp., from Upper Chalk, Keady Hill, London-
derry.

52 BRITISH MARINE CRETACEOUS OSTRACODA

MEASUREMENTS Length Height
4 specimens. : . 0:78-0:80 mm. 0-38 mm.

DESCRIPTION. Valves sinaill letioeelly compressed. Dorsal and ventral margins
straight, converging slightly posteriorly. Dorsal margin with three large equally
spaced spines ; anterior and posterior margins similarly spined particularly on
their lower halves. A narrow ventral ala occurs with subsidiary spines along its
crest. Lateral surface smooth, eye tubercle prominent. A low anterior marginal
rib occurs which is continued into the ala ventrally.

Hinge strongly amphidont, having an elongate crenulate posterior tooth and a
high smooth anterior tooth in the right valve. There is no accommodation groove
in the left valve.

ReMARKs. This species is rather similar to A. vobusta but the ala is much narrower
and more laterally directed. The strong spination of the margins is the most easily
distinguishable feature.

Family BYTHOCYTHERIDAE
Genus MONOCERATINA Roth 1928

Monoceratina acanthoptera (Marsson)
(Ele tice 2)

1880 Cytheve acanthoptera Marsson : 45, pl. 3.
1938 Monoceratina acanthopteya (Marsson) ; Veen : 3.

MATERIAL. A right valve, B.M.N.H., Io. 1206, from the Upper Chalk at Norwich.

MEASUREMENTS Length Height

Right valve (B.M.N.H., Io. 1206) : 0-52 mm. 0:26 mm.

REMARKS. This species, which appears to be confined to the topmost Chalk
was not recorded by Jones. His form Cythere umbonata acanthoptera (Jones & Hinde
1890 : 41) is much larger, and reticulate. M. acanthoptera has often been confused
with Monoceratina longispina (Bosquet) but is smaller, less inflated and has the
lateral spine behind rather than below the median sulcus. The sulcus therefore is
not terminated abruptly. The surface in both species 1s smooth.

Monoceratina bonnemai sp. nov.
(Cede Senaless 5).6))

DERIVATION OF NAME. After J. H. Bonnema in recognition of his work on the
Chalk of W. Europe.

Dracnosis. Monoceratina, with smooth surface and two laterally directed spines
on ventro-lateral surface. Prominent bulbous tubercle occurs on anterior half of
dorso-lateral surface.

Horotyre. B.M.N.H., Io. 1169, a right valve from the Cambridge Greensand
of Barrington (Cambs.).

PaRATYPES. B.M.N.H., Io. 1170-71, left and right valves from the same locality.

MEASUREMENTS Length Height Width

Left valve (B.M.N.H., Io. 1169,
holotype) . ; ; - O77 5.mim: 0°32 mm. 0°33 mm

BRITISH MARINE CRETACEOUS OSTRACODA 53

Description. Valves smooth, elongated. Dorsal and ventral margins straight
and parallel ; posterior drawn out into a blunt postero-dorsal caudal extension.
Lateral surface divided by a vertical median sulcus. Ventrally there are two
prominent horn-like spines ; a large one posterior to the sulcus and a smaller one
anterior to it. The two spines are partially fused at their base and limit the sulcus
ventrally. A large circular bulbous node occurs on the dorsal part of the antero-
lateral surface. The valve margin bears a series of small tubercles antero-ventrally.
A narrow ridge runs along the posterior half of the dorsal margin.

RemARKS. The ornament of this species is quite unlike any other published
Cretaceous species.

Monoceratina cf. longispina (Bosquet)
(Rlesstie= x)

1854 Cytherve longispina Bosquet : 86, pl. 6, figs. 7a—d.
1941 Monoceratina longispina (Bosquet) Bonnema : 40, pl. 6, figs. 67—76.

MatTeriAL. B.M.N.H., Io. 1204, Io. 1581, from the Cambridge Greensand of
Barrington (Cambs.).

ReMARKS. This form was not recorded by Jones from the British Cretaceous.
In some ways it is similar to his Cythere umbonata acanthoptera and the latter was
thought to be conspecific with this species by Bonnema (1941). It differs, however,
in being smooth or only faintly reticulate and more inflated. The lateral spine is
conical in shape being short with a wide base whilst C. wmbonata acanthoptera has
a longer and more slender spine. The sulcus is very strong but is terminated
abruptly against the swollen base of the lateral spine.

Bosquet records this species from the Senonian whilst the British specimens
are from the Cambridge Greensand of Albian/Cenomanian age. As I have not
seen Bosquet’s specimens the identification of this species is based on Bonnema’s
material and figures.

Monoceratina montuosa (Jones & Hinde)
(Pie ties 3)
1890 Cythevopteron cuspidatum montuosa Jones & Hinde : 38, pl. 3, figs. 14-16.
21934 Monoceratina montuosa (Jones & Hinde) Alexander : 62, pl. 8, fig. 5.
1941 Monoceratina montuosa (Jones & Hinde) ; Bonnema : 41, pl. 7.

Diacnosis. Monoceratina with two prominent ventro-lateral spines. Dorsal
and ventral margins straight and parallel. Dorsal margin with a row of four tubercles,
the anterior one being the eye tubercle. Lateral surface smooth.

LectotyPe. A right valve, B.M.N.H., I. 2478, from the Island of Magee though
labelled as Cytheropteron cuspidatum the specimen undoubtedly belongs to Jones’
form Cytheropteron cuspidatum montuosa and is here considered as lectotype.

C. cuspidatum montuosa is said by Jones to come from Magee whilst he records
true C. cuspidatum from Norfolk.

MEASUREMENTS Length Height Width

Right valve (B.M.N.H., I. 2478) 0-78 mm. 0-30 mm. 0-27 mm.

54 BRITISH MARINE CRETACEOUS OSTRACODA

DescriPTION. The shape and ornament of this species make it distinct. It
bears two rather thick short lateral spines, the posterior of the two being the larger.
The valves are strongly compressed laterally. Four tubercles occur along the
dorsal margin, the one immediately anterior to the median sulcus being about
twice the size of the others. The dorsal margin is long and straight, the ventral
margin is short, straight and parallel. Itisstrongly spined anteriorly and tuberculate
posteriorly.

REMARKS. This species differs from M. cuspidata s.s. in having two ventral
spines. Specimens of the latter species are missing from the Jones collection and
its exact interpretation is therefore doubtful. M. tricuspidata (Jones & Hinde) is
smaller and has three long ventral spines.

Monoceratina pedata pedata (Marsson)
(Pl. 3, figs. 9-14)
1880 Cytheve pedata Marsson : 46, pl. 3, fig. 16a.
1890 Cytheropteron pedatum (Marsson) Jones & Hinde : 38, pl. 4, figs. 33-35.
?1929 Cytherura spooneri Israelsky : 6, pl. 4a, fig. 7.
1933 Monoceratina pedata (Marsson) Alexander : 203, pl. 27, figs. 15a, b.
1934 Monoceratina pedata (Marsson) ; Alexander : 60.
1939 Monoceratina pedata (Marsson) ; Alexander : 66.
1941 Monoceratina pedata (Marsson) ; Bonnema : 29, pl. 6, figs. 27-30.
1957 Monoceratina pedata (Marsson) ; Butler & Jones : 24, pl. 4, fig. 3
MATERIAL. (i) B.M.N.H., Io. 355 (Jones & Hinde), Chalk, Dunstable. (ii)
B.M.N.H., Io. 372, Io. 1588 (Jones & Hinde), Chalk, Keady Hill. (ii) B.M.N.H.,
I. 2492, Io. 1587 (Jones & Hinde, 1890, pl. 4, figs. 33-35), Upper Chalk, Gobbins.
(iv) B.M.N.H., In. 53094-95, In. 53236-41, In. 53242-47, Io. 1584-86 (Rowe),
Upper Chalk, Norwich.
MEASUREMENTS Length Height
Left valves j ‘ I-I0-I'I2 mm. 0:52-0:55 mm.
REMARKS. The species is s alone in the uppermost Chalk in this country but
is found occasionally as low as the Cambridge Greensand. It has in the past been
confused with M. wmbonata but is larger and more triangular lacking the strong
median sulcus of the latter and having a thicker and longer spine. The reticulate
ornament bears no relationship to this spine, being a regular mesh over the whole
of the lateral surface. Small tubercles often occur at the intersections in the reticula-
tion. MM. wmbonata has parallel dorsal and ventral margins and is not as drawn out
posteriorly. One of the clearest characteristics of M. pedata pedata is the double
row of spines along the anterior margin and the single row of spines along the posterior
and ventral marginal areas. Apart from the spine the lateral surface is devoid of
major nodes and spines.

Monoceratina pedata salebrosa (Jones & Hinde)
(Pl. 3, figs. 15, 16)
1890 Cytheropteron pedatum salebrosa Jones & Hinde : 39, pl. 3, fig. 8 ; pl. 4, fig. 32.
Diacnosis. A subspecies of Monoceratina pedata with subdued reticulate

BRITISH MARINE CRETACEOUS OSTRACODA 55

ornament and a series of small tubercles sporadically located upon the lateral
surface. Tubercles most prominent in a line ventral of the major lateral spine.

LecTotyPeE. B.M.N.H., Io. 2208, a left valve (Jones & Hinde 1890, pl. 3, fig. 8)
from the Upper Chalk of Whiteabbey, Antrim, here designated.

PARALECTOTYPE. A right valve Io. 2209, from the same locality.

MEASUREMENTS Length Height

Left valve (B.M.N.H., Io. 2208, lectotype) . 0-91 mm. 0-47 mm.

REMARKS. The two specimens are undoubtedly Jones’ original material. They
are very closely related to M. pedata pedata. They differ principally in the nature
of the surface ornament. The reticulation is subdued and the valves have a rather
undulating appearance. Small tubercles are found, particularly clustered around
the large lateral spine and in a row below it. The left valve possesses a marked
median sulcus but in the right valve it is hardly visible. In shape and marginal
ornament the subspecies is identical with M. pedata pedata.

Monoceratina pedata laevoides Bonnema
(Ela tie.7 17)
?1880 Cythere pedata laevis Marsson : 45, pl. 3, figs. 160, c.
1941 Monoceratina laevoides Bonnema : 29, pl. 6, figs. 47-53.

MATERIAL. (i) B.M.N.H., Io. 355 (Jones & Hinde 1890) from the Chalk of
Dunstable. (ii) B.M.N.H., Io. 1589 (Rowe), Upper Chalk, Norwich.

MEASUREMENTS Length Height

Left valve (B.M.N.H., Io. 1589) : - OO( saainn, 0-49 mm.

REMARKS. Identical with M. pedata pedata apart from the lack of reticulation
on the lateral surface. The valves are smooth and shiny with a well marked median
sulcus. Small tubercles are scattered over the surface particularly dorsally and in
a line below the large lateral spine. The largest of the specimens is rather smaller
than adults of 1. pedata pedata. The close association and similarity of this form
with M. pedata pedata suggest that this subspecies could be an extreme variant of
the latter. However, until further material is available, it is preferred to consider
these forms as separate subspecies.

Monoceratina sherborni (Jones & Hinde)
(PL. 3, fig. 4)

1890 Cytheropteron sherborni Jones & Hinde : 42, pl. I, figs. 33, 34 ; pl. 4, figs. 20, 21.
MATERIAL. B.M.N.H., In. 53166, a left valve (Rowe) Upper Chalk, Norwich.
MEASUREMENTS Length Height

Left valve (B.M.N.H., In. 53166) : . 0.86 mm. 0-47 mm.

Remarks. There is no trace of the original material but a comparative specimen
is figured. The species lacks the prominent lateral spine but shows all the internal
features of the genus Monoceratina. The surface is strongly divided by the median
sulcus. The lateral surface is ornamented by concentric ridges bearing small
spines. The hinge is a simple bar. The shape and inflation are somewhat remi-
niscent of /. wmbonatoides but it is not as elongate, and lacks the spine and flattened
anterior and posterior marginal areas.

56 BRITISH MARINE CRETACEOUS OSTRACODA

Monoceratina tricuspidata (Jones & Hinde)
(er 3p figs. 7> 8)
1890 Cytheropteron cuspidatum tricuspidata Jones & Hinde : 38, pl. 3, figs. 6, 7.
1936 Monoceratina tricuspidata (Jones & Hinde) Veen : 9, 42, 43, pl. 2, figs. 4-11.
1941 Monoceratina tricuspidata (Jones & Hinde) ; Bonnema : 40, pl. 6, figs. 77-80.
1941 Monoceratina tricuspidata (Jones & Hinde) ; Triebel : 353.

Driacnosis. Small Monoceralina with three prominent ventro-lateral spines.
Other subsidiary tubercles occur over the lateral surface but no reticulation. Eye
tubercle well developed.

LecToTyPeE. B.M.N.H., Io. 1583 (Jones & Hinde 1890), Upper Chalk, Keady
Hill.

OTHER MATERIAL. B.M.N.H., lo. 1202, Io. 1582, two specimens from the Upper
Chalk, coranguinum Zone, Sonning, Berks.

MEASUREMENTS Length Height

Right valve (B.M.N.H., Io. 1583, lectotype) . 0:65 mm. 0:25 mm.

REMARKS. The species is similar in shape to MW. montuosa but is smaller and has
three very prominent lateral spines. It occurs throughout the Upper Chalk in
Britain, but is never very abundant.

Monoceratina umbonata (Williamson)
(Pl. 4, figs. 3, 4, 6-8)

1847 Cytherina umbonata Williamson : 82, pl. 4, fig. 78.

1849 Cythere umbonata (Williamson) Jones : 12, pl. 2, figs. 3a-g.

1870 Cytheropleron umbonatum (Williamson) Jones : 74, 76.

1872 Cytheropteva umbonata (Williamson) Williamson : 136.
?1880 Cythere umbonata (Williamson) ; Marsson : 45, pl. 3, figs. 15a—c.

1890 Cytheropteron umbonatum (Williamson) ; Jones & Hinde : 40, pl. 1, figs. 21-26.

1890 Cytheropteron umbonatum longispinata Jones & Hinde : 41, 42, pl. 3, figs. 11, 12; pl. 4,

figs. 30, 31.

1893 Cytheropteron umbonatum (Williamson) ; Chapman & Sherborn : 347.
21934 Monoceratina umbonata (Williamson) Alexander : 62, pl. 8, fig. 9.
1941 Monoceratina umbonata (Williamson) ; Bonnema : 29, pl. 6, figs. 54-62.

MATERIAL. (i) B.M.N.H., In. 51595-51601, figured Jones (1849, pl. 2, figs. 3a-g)
from the Chalk Detritus at Charing. (ii) B.M.N.H., Io. 314 (Morris) Charing ;
B.M.N.H., In. 19382-85 (Hinde) Upper Greensand, Warminster; B.M.N.H.,
I. 2676-77 (Chapman) Gault Clay, Folkestone. (iii) B.M.N.H., Io. 1203, Io. 1590,
Cambridge Greensand, Barrington (Cambs.). (iv) Hull University 17.C.8.1, Red
Chalk, Speeton, E. Yorks.

MEASUREMENTS Length Height

Adult left valve (B.M.N.H., Io. 1203) . 2) 0-78 mm: 0-34 mm.

REMARKS. This species is extremely variable in ornament and degree of inflation,
the ornament being reticulate but also often strongly spinose. The original figure
by Williamson is drawn from an oblique angle and those of Jones (1849) from the
same locality are generally taken as typical. Most of Jones’ figured specimens
are pre-adults, the larger adult forms being rare. The spinose variants were
grouped by Jones & Hinde (1890) into a distinct variety : var. longispinata. All

BRITISH MARINE CRETACEOUS OSTRACODA 57

intermediates between the spinose and simple reticulate forms are however found
and therefore no separation can be made on this basis. The forms figured by Jones
& Hinde as var. longispinata were adult specimens which would be expected to have
a more strongly developed ornament than the young moults. The length and
changes in shape of the lateral spine described as a varietal difference are due to
breakage and forms described as having a short, broad, flat topped spine have the
spine broken.

The degree of inflation is particularly variable. The lateral surface anterior to the
median sulcus is generally flattened in true M. wmbonata. Forms with inflated
anterior lateral areas described by Jones & Hinde (1890) as var. acanthoptera Marsson
are renamed Monoceratina umbonatoides (see below). These forms, often with a
pronounced node on the antero-lateral area, have almost certainly evolved from
M. umbonata and transitional forms do occur. M. umbonata is largely confined to
Albian and Cenomanian sediments, however, whilst the Upper Cretaceous members
of this plexus are found to be M. wmbonatordes.

M. umbonata differs from M. pedata pedata principally in shape. It has a well
marked median sulcus and the reticulation is often arranged concentrically around
the lateral spine.

Monoceratina umbonatoides nom. nov.
(Pl. 4, figs. 5, 6)

1890 Cytheve umbonatum acanthoptera (Marsson) ; Jones & Hinde: 41, pl. 1, figs. 11-13 ;

pl. 4, figs. 22-29.

Lectotype. B.M.N.H., Io. 1592 (Jones), Magee, Antrim, here designated.

OTHER MATERIAL. (i) B.M.N.H., Io. 374 (Jones & Hinde) Upper Chalk, Keady
Hill, Derry. (ii) B.M.N.H., Io. 1205, Io. 1591, three specimens from the Upper
Chalk, coranguinum Zone, Sonning, Berks.

MEASUREMENTS Length Height

Left valve (B.M.N.H., Io. 1205) : . 0.65 mm. 0-39 mm.

Remarks. This species differs from M. wmbonata in the strong inflation of the
antero-lateral area. A large node is usually present antero-dorsal to the median
sulcus. The species seems to be restricted to the Upper Chalk and is probably a
direct descendent from M. wmbonata. It differs from Marsson’s form (1880, pl. 3,
figs. 14a—c) in the reticulate ornament and in having the spine posterior to rather
than below the median sulcus.

Family PROTOCYTHERIDAE
Genus PROTOCYTHERE Triebel 1938
Protocythere consobrina Triebel
(Pl. 5, figs. 17-19)
1938 Protocytheve consobrina Triebel : 184, pi. 1, figs. 6, 7.

MatTeriAL. B.M.N.H., Io. 1190, Io. 1603-05 from the Lower Gault, Culham,
Oxfordshire.

58 BRITISH MARINE CRETACEOUS OSTRACODA

MEASUREMENTS Length Height
Male left valve (Io. 1605) . ; : . 1:05 mm. 0°57 mm.
Female left valve (Io. 1190) F : . 0-92 mm. 0:57 mm.

REMARKS. This species is very similar to Protocythere triplicata (Roemer) from
the Hauterivian and Barremian. The principal differences are that the ribs are
less convex and the anterior hinge element is set slightly out of line, the median
groove in the right valve passing above the anterior tooth. Specimens of P. triplicata
from the Middle Barremian at Speeton, E. Yorkshire, are figured on PI. 5, figs. 12,
Topelese

P. consobrina lacks the ventral riblets of P. lineata and has smooth intercostal
areas. The instars have subdued ribbing whilst those of P. lineata are still strongly
emphasised, obscuring the dorsal margin.

Protocythere lineata (Chapman & Sherborn)
(Pl. 5, figs. 1-8)

1849 Cytheve (Cytherveis) tviplicata (Roemer) ; Jones : 18, pl. 3, figs. ga—/h.
1870 Cythereis tyviplicata (Roemer) Jones : 75-76.

1890 Cythereis triplicata (Roemer) ; Jones & Hinde : 19, pl. 1, figs. 56-61.
1893 Cythereis triplicata lineata Chapman & Sherborn : 348, pl. 14, fig. 5.
1898 Cythereis triplicata lineata Chapman & Sherborn ; Chapman : 338.
1938 Protocythere jonest Triebel : 186, pl. 1, figs. 8—ro.

1956 Protocythere jonesi Triebel ; Deroo : 1514.

Diacnosis. Protocythere with three prominent longitudinal ribs. The ventral
one bears small longitudinal riblets upon its surface. Intercostal areas with irregular
network of small cross ribs.

LectotyPe. B.M.N.H., I. 2704, figured Chapman & Sherborn (1893, pl. 14, fig. 5)
from the Gault Clay, Middle Albian at Folkestone, Kent, here designated.

OTHER MATERIAL. (1) B.M.N.H., In. 51665-66, In. 51668-72 figured Jones
(1849, pl. 3, figs. ga—-g) from the Detritus at Charing and from Folkestone Gault
Clay. (ii) B.M.N.H., Io. 309 (Morris) from the Detritus at Charing. (iii) B.M.N.H.,
I. 2464 (Jones & Hinde 1890) from the Chalk marl at Didcot. (iv) B.M.N.H.,
Io. 1187, Io. 1596-1600 from the Upper Gault at Burwell, Cambs.

MEASUREMENTS Length Height

Right valve (B.M.N.H., I. 2704, lectotype) . 0-60 mm 0-30 mm.

REMARKS. This species identified by Jones (1849) as Cythereis triplicata (Roemer).
was renamed by Triebel (1938). Unfortunately a specimen described as a subspecies
by Chapman & Sherborn (1893) has been found to be a young stage of C. tviplicata
sensu Jones. This subspecies C. tviplicata lineata has priority over Triebel’s subse-
quent correction and therefore provides the valid specific name.

The species has been well described by Triebel. Its particular characteristics
include the longitudinal riblets upon the ventral rib and the numerous small ribs
which cross the inter-costal areas. The prominence of these ribs is variable, a fact
which is particularly apparent amongst specimens of different states of preservation.
P. lineata is closely related to P. consobrina which occurs in equivalent strata in

BRITISH MARINE CRETACEOUS OSTRACODA 59

Southern England. The latter is, however, more strongly inflated and lacks the
ventral riblets. The intercostal areas are smooth and the dorsal and ventral ribs
are less arched.

Another related form is P. tricostata which has the intercostal areas strongly
reticulate. The longitudinal ribs are longer and keel-like and do not obscure the
dorsal and ventral margins to the same extent.

Protocythere tricostata Triebel
(Bie 5 tigsi4. nO)
1938 Protocythere tricostata Triebel : 190, pl. 2, figs. 17-22.
MATERIAL. B.M.N.H., Io. 1188, four specimens from the Middle Albian at
Speeton, E. Yorkshire.

MEASUREMENTS Length Height
Male left valve (B.M.N.H., Io. 1188) . =) 0:90 mm: 0-47 mm.
Female left valve (B.M.N.H., Io. 1188) . 0-80 mm. 0-47 mm.

Protocythere rudispinata (Chapman & Sherborn)
(Pl. 5, figs. 9-11)
1893 Cythereis rudispinata Chapman & Sherborn : 348, pl. 14, figs. 6, 7.

DiaGnosis. Small Protocythere with three longitudinal rows of large flat topped
spines running across the lateral surface. Anterior margin bearing a row of spines.
Intercostal areas smooth.

LectotyPe. B.M.N.H., I. 2705 figured Chapman & Sherborn (1893, pl. 14, fig. 6),
a left valve from the Lower Gault at Folkestone, here designated.

PARALECTOTYPE. B.M.N.H., I. 2705 figured Chapman & Sherborn (1893, pl. 14,
fig. 7), a right valve from the same locality.

OTHER MATERIAL. B.M.N.H., Io. 1189 from the Lower Gault at Henfield,
Sussex.

MEASUREMENTS Length Height

Left valve (B.M.N.H., I. 2705, lectotype) . 0:59 mm. 0:33 mm.

DEscRIPTION. Valves relatively small, compressed laterally. Dorsal and ventral
margins straight and subparallel. The lateral surface bears three longitudinal rows
of stout flat-topped spines. A further row of similar spines runs along the ventral
surface, whilst smaller spines are often found between the two major ventral rows.
The weak anterior marginal rib bears a double row of laterally directed spines.
Anterior and posterior margins tuberculate. Intercostal areas smooth. Normal
pore canals rare, usually connected with a spine on lateral surface.

Duplicature broad and crossed by numerous radial pore canals which curve
upwards antero-dorsally. Hinge crenulate merodont with strongly divided stepped
terminal elements.

REMARKS. The shape, marginal features and hinge place Chapman & Sherborn’s
specimens in the genus Pyvotocythere rather than Cythereis. The form described by
Triebel (1940, pl. 4, figs. 47-50) and by Deroo (1956) differs fundamentally, being
larger, compressed dorsally, more strongly convergent posteriorly and lacks the

60 BRITISH MARINE CRETACEOUS OSTRACODA

prominent hinge ear in the left valve. It also differs in the details of the marginal
area, hinge, and normal pore canals and falls within the latter genus. Further
differences are in the shorter nature of the spines and the absence of spines along
the ventral surface.

Genus VEENIA Butler & Jones 1957

Veenia barringtonensis sp. nov.
(Pl. 6, figs. 1-3)

DraGnosis. Veenia, with three longitudinal ribs which almost join posteriorly
Ventral rib connected to anterior margin at one-third height, also bears row of
laterally divided tubercles at posterior end.

HoLotyrPeE. B.M.N.H., Io. 1172, a female left valve from 1 ft. below the
Cambridge Greensand, Barrington (Cambs.).

PARATYPES. Four specimens, B.M.N.H., lo. 1173-76, from the same horizon.

MEASUREMENTS Length Height

Male left valve (B.M.N.H.., lo. 1173,

paratype) 0-87 mm. 0-47 mm.
Female left valve (B.M.N.H., Io. 1172

holotype) 0-79 mm. 0°47 mm.

DESCRIPTION. Valves elongate, compressed, anterior broadly rounded, posterior
pointed at mid-height in the right valve but forming a blunt point at the postero-
dorsal angle in the left valve. Dorsal margin straight, ventral margin straight or
weakly convex. Three longitudinal ribs cross the lateral surface. The dorsal rib
is rather sinuous and is equal in length to the median hinge element, obscuring the
margin in its central part but curving downwards anteriorly and posteriorly. The
median rib is shorter and straight, being connected with a low muscle node anteriorly.
The ventral rib is strongly convex. Anteriorly it is connected to the margin at
one-third height by a short horizontal cross rib, posteriorly it bears a row of 5 or
6 small laterally directed tubercles on its crest. The anterior and posterior margins
are tuberculate, each tubercle corresponding to the extremity of a radial pore canal.

Duplicature broad, crossed by a few, thick, radial pore canals. These number
10 anteriorly and 6 posteriorly, being concentrated antero- and postero-ventrally,
the upper ones curving dorsally. Inner margin and line of concrescence coincide.

Hinge strongly amphidont having in the right valve two high, divided, terminal
teeth separated by a long, locellate, median groove deepened anteriorly into a
smooth socket. The socket and groove are open ventrally but are bounded dorsally
by a high, smooth bar. The median groove extends somewhat above the terminal
elements. In the left valve there are two strong, divided sockets, separated by a
high strongly denticulate bar. The bar bears a prominent smooth tooth at its
anterior end and is separated from the dorsal margin by a narrow shelf. In front
of the anterior socket the margin is elongated into a keel-like process which fits
into a depression above the anterior tooth in the right valve.

RemARKS. JV. barringtonensis differs from the closely related V. harris:ana in
the shape of the longitudinal ribs and the greater emphasis of the ornament.

BRITISH MARINE CRETACEOUS OSTRACODA 61

Veenia harrisiana (Jones)
(Pl. 4, fig. r ; Pl. 6, figs. 4-11)

1849 Cytherve (Cythereis) interrupta (Bosquet) ; Jones : 16, pl. 2, figs. 6a—g.
1849 Cythere (Cythereis) quadrilaterata (Roemer) ; Jones : pl. 4, figs. 10h, 2.
1870 Cythere harvisiana Jones : 75, 76 (new name).
1890 Cytheve havvisiana Jones ; Jones & Hinde : 16, pl. 1, figs. 47-52.
1890 Cythere harvisiana veticosa Jones & Hinde : 18, pl. 1, fig. 46.
1890 Cythere harvisiana setosa Jones & Hinde : 17, pl. 1, figs. 43-45.
1890 Cythereis auriculata (Cornuel) ; Jones & Hinde : 19, pl. I, figs. 53-55.
1893 Cythere harrisiana Jones ; Chapman & Sherborn : 346.
1893 Cythere havrisiana rveticosa Jones & Hinde ; Chapman & Sherborn : 346.
1893 Cythere harvrisiana setosa Jones & Hinde ; Chapman & Sherborn : 346.
1893 Cythere auriculata (Cornuel) ; Chapman & Sherborn : 346.
1893 Cythere lineatopunctata Chapman & Sherborn : 348, pl. 14, fig. 4.
1893 Cythere koninckiana (Bosquet) ; Chapman & Sherborn : 348, pl. 14, fig. 2.
1898 Cythere harvvisiana Jones ; Chapman : 335.
1898 Cythere havrisiana reticosa Jones & Hinde ; Chapman : 336.
1898 Cythere harvisiana setosa Jones & Hinde ; Chapman : 335, 336.
1898 Cythere koninckiana (Bosquet) ; Chapman : 337, 338, figs. 4a, b.
1898 Cytheveis auriculata (Cornuel) ; Chapman : 338.
1938 Protocythere auviculata (Cornuel) Triebel : 195, pl. 2, figs. 27-31.
1956 Protocythere triebeli Deroo : 1515 (new name).
1963c Veenia triebeli (Deroo) Kaye : 233, pl. 18, figs. 10, 11.
?1963c Homocythere reticulata Kaye : 234, pl. 18, figs. 8, 9.

DiaGnosis. Veenia with three low, inflated, straight parallel longitudinal ribs.
Hinge ears prominent in left valves. Lateral surface smooth-pitted. Marked
changes occur in ornament throughout ontogeny.

LectotyrPe. B.M.N.H., In. 51663 figured Jones (1849, pl. 2, fig. 6d), a pre-adult
right valve from the Gault Clay, Folkestone, here designated.

PARALECTOTYPES. B.M.N.H., In. 51657-62 figured Jones (1849, pl. 2, figs. 6a—c,
e-g), figs. 6b, c, g from the Gault at Folkestone, figs. 6a, e, f from the Detritus at
Charing.

OTHER MATERIAL. (i) B.M.N.H., I. 2689 (Chapman & Sherborn) ; B.M.N.H.,
I. 2690 (Chapman & Sherborn var. reticosa) ; B.M.N.H., I. 2691, Io. 1610 (Chapman
& Sherborn var. setosa) ; B.M.N.H., I. 2680 (Chapman & Sherborn C. auriculata) ;
B.M.N.H., I. 2703 (Chapman & Sherborn C. lineatopunctata pl. 14, fig. 4) all from
the Gault Clay at Folkestone. (ii) S.M.B. 40574-77, B. 40580-81, B. 40585-88,
B. 40621 (Chapman 1898) all from the Cambridge Greensand at Swaffham. (iii)
B.M.N.H., Io. 1606-09 from the Middle Albian at Speeton, E. Yorkshire.

MEASUREMENTS Length
Male left valves. ‘ y ‘ : . 0:96-1:00 mm.
Female left valve . : : : ‘ . 0:86-0:90 mm.
Penultimate instars : : : : . 0:66-0-75 mm.
Instars group A . : : : : . 0°52-0°56 mm.
Instars groupB . : : : : . 0°43-0-45 mm.
Instars groupC . : ; : : . 0:36-0:38 mm.

Instars group D_. 3 ; : : . 0:30-0:32 mm.

62 BRITISH MARINE CRETACEOUS OSTRACODA

REMARKS. This species must be amongst the most confused of all Cretaceous
ostracoda. Most of the early references refer to pre-adult valves as the adult
form was not described until 1890. The difference in shape and ornament between
the adults and pre-adults led to their being considered as separate species for a
considerable time. The adults, first included within Protocythere auriculata (Cornuel)
were renamed P. triebeli by Deroo in 1956. The pre-adults, which offer the first
valid specific name, were further subdivided on a basis of ornament. This ornament
varies from completely smooth to strongly reticulate and all intermediate stages
are usually seen within the same sample (PI. 4, fig. 1). Ona basis of the amphidont
hinge the writer (1963c) placed the species within the genus Veenza.

A further confusing feature is that weak sexual dimorphism is shown by the
penultimate moults ; the valve proportions being interpreted as varietal differences
by early authors.

The adult specimens differ from the pre-adults in the following ways :—The long
margins are parallel, and a prominent hinge ear is developed in the left valve. The
ornament of longitudinal ribs is increased in length and prominence and an anterior
marginal rib is introduced. The muscle node is also subdivided. The duplicature
doubles in width and the radial canals become longer and curve upwards antero-
dorsally. The hinge is strengthened and changes from merodont to amphidont.

The synonomy only includes references with figures or those of which the author
has seen the actual specimens. Homocythere reticulata Kaye is here tentatively
included in the synonomy. Its intimate occurence with pre-adults of V. harrisiana
where adults are absent may indicate that it is a form of the adult found under
unusual ecological conditions.

Family TRACHYLEBERIDIDAE
Genus CYTHEREIS Jones 1849
Cythereis corrigenda nom. nov.
(Pl. 7, figs. 6, 9)
1940 Cythereis rudispinata Chapman & Sherborn ; Triebel, 200, pl. 4, figs. 47-50.
1956 Cythereis vudispinata Chapman & Sherborn ; Deroo : 15106.

MaTerRIAL. B.M.N.H., Io. 1198, Io. 1616-17, from the Lower Gault, dentatus
Zone, Culham, Oxfordshire.

MEASUREMENTS Length Height
Male left valve (B.M.N.H., Io. 1617) . . 0-87 mm. 0-42 mm.
Female left valve (B.M.N.H., Io. 1198) 0-7-7, mim. 0-42 mm.

Remarks. Triebel’s specimens differ significantly in shape, size, nature and
distribution of ornament, marginal features and hingement from Chapman &
Sherborn’s specimens (1893 : 248, pl. 14, figs. 6, 7). The latter specimens falling
within the genus Protocythere. Triebel’s form has therefore been given a new name.
Cythereis matronae Damotte & Grosdidier (1963) is very similar to C. corrigenda,
but it is stated to differ in its greater size and lack of reticulation. Triebel’s speci-
mens, however, are of similar size and have smooth intercostal areas.

BRITISH MARINE CRETACEOUS OSTRACODA 63

Cythereis folkstonensis nom. nov.
(Pl. 7, figs. 1-5)
1849 Cythere (Cythereis) quadrilatevata (Roemer) Jones : 18, pl. 3, figs. 10a—c, e-f (non pl. 3,
fig. rod ; pl. 4, figs. g—h).
1870 Cythere quadrilaterata (Roemer) ; Jones : 75, 76.
1890 Cytheveis quadrilatevata (Roemer) ; Jones & Hinde : 20, pl. 1, figs. 69-71, 74-75.

Diacnosis. Large Cythereis with three longitudinal rows of tubercles. Lateral
surface devoid of reticulation. Eye tubercle and muscle node prominent.

Lectotype. B.M.N.H., In. 51678 figured Jones (1849, pl. 3, fig. 10a) from the
Gault Clay at Folkestone, here designated.

PARALECTOTYPES. B.M.N.H., In. 51679-80, In. 51682~-83 figured Jones (1849
pl. 3, figs. 10), c, e, f) from the Gault Clay at Folkestone.

OTHER MATERIAL. B.M.N.H., Io. 1192, Io. 1614-15, from the Upper Gault at
Burwell, Cambs.

MEASUREMENTS Length Height

Left valve (B.M.N.H., In. 51678, lectotype) . 1:12 mm. 0-60 mm.

ReMARKS. This species having been wrongly attributed by Jones is here renamed.
C. folkstonensis appears to be restricted to the Albian, most of the specimens from
the Chalk are referable to such species as C. lurmannae, C. cornueli, Veemia harrisiana,
ete.

The most diagnostic features of C. folkstonensis are the rows of tubercles along
the longitudinal ribs ; the separation of the median longitudinal rib and the muscle
node ; the smooth intercostal areas. Cythereis folkstonensis is most closely related
to Cythereis glabrella Triebel but is less inflated and has spines on the longitudinal
tibs. It is likely that it is related to its reticulate counterpart Cytherets reticulata
(Jones & Hinde).

Cythereis lonsdaleiana Jones
(Ble less 7010)

1849 Cythere (Cythereis) lonsdaleiana Jones : 20, pl. 5, figs. 12a, b (non fig. 12c).
1870 Cytheve lonsdaleiana Jones : 75, 76.
1880 Cythere filicosta Marsson : 43, pl. 3, figs. 12a, b.
1890 Cythereis lonsdaleiana Jones ; Jones & Hinde : 27, pl. 1, figs. 64, 65.
1941 Cythereis filicosta (Marsson) ; Bonnema : 132, pl. 4, figs. 48-53 (non pl. 7, figs. 55-58).

Diacnosis. Cythereis with keel-like longitudinal ribs. Dorsal rib formed of
series of short oblique cross ribs. Median rib short and joined to large smooth
muscle node.

LectotypPe. B.M.N.H., In. 39012 figured Jones (1849, pl. 5, fig. 12b) from the
Upper Chalk at Norwich, here designated.

PARALECTOTYPE. B.M.N.H., In. 39011 figured Jones (1849, pl. 5, fig. 12a)
from the same locality.

OTHER MATERIAL. B.M.N.H., Io. 1196 and Io. 1618 from the Upper Chalk at
Norwich.

MEASUREMENTS Length Height

Right valve (B.M.N.H., In. 39012, lectotype) 0-63 mm. 0:37 mm.

64 BRITISH MARINE CRETACEOUS OSTRACODA

REMARKS. Jones’ pl. 5, fig. 12c (B.M.N.H., In. 39013) is of a much larger,
differently ornamented form. Marsson’s species Cythere filicosta as redescribed
after examination of the original types by Bonnema (1941) fits Jones’ original
description exactly. The multiple nature of the dorsal rib was the most diagnostic
feature according to Bonnema who used this criterion for separating the form from
Cythereis semiplicata (Reuss). The interior of the valves are shallow, with a wide
duplicature. The hinge is strongly amphidont with high, weakly lobed terminal
teeth in the right valves.

Specimens referred to this species by Chapman and other authors from the
Gault Clay of S.E. England (B.M.N.H., I. 2683) are instars of Cythereis reticulata
and allied forms.

Cythereis macrophthalma (Bosquet)
(Pl. 6, figs. 12-15, 17)
1847 Cypridina macrophthalma Bosquet : 16, pl. 3, figs. 3a—d.
1936 Cythereis macrophthalma (Bosquet) Veen : 7, pl. 2, figs. 43-48.
1958 Cythereis macrophthalma (Bosquet) ; Howe & Laurencich : 212.

MATERIAL. (i) B.M.N.H., Io. 354 from the Chalk Rock at Dunstable ; B.M.N.H.,
Io. 351 from the Chalk at Norwich ; B.M.N.H., Io. 345 from the Chalk at Colchester
all mounted by Jones & Hinde (1890) as C. quadrilaterata. (ii) B.M.N.H., lo. 1193
from the Upper Chalk at Norwich.

MEASUREMENTS Length Height
Male carapace (B.M.N.H., Io. 345) . 0-85 mm. 0:47 mm.
Female left valve (B.M.N.H., lo. 345). Org mnie 0-47 mm.

REMARKS. Cythereis quadrilaterata sensu Jones appears to be confined to Albian
sediments and the specimens from the Chalk so labelled by Jones are all referable
to C. macrophthalma. Bosquet’s original figures are so bad that identification is
here largely based on Veen’s illustrations.

In shape the species is somewhat akin to Protocythere or Veenia but possesses
typical hinge and marginal features of the genus Cythereis. The intercostal areas
are smooth and the muscle node is separated from the median rib. The species
lacks the spination and inflation of true Cytherers quadrilaterata.

Cythereis ornatissima s.]. (Reuss 1846)
(EUS S higSack, Zen)
1846 Cytherina ornatissima Reuss : 104, pl. 24, figs. 12, 18.
21846 Cytherina ciliata Reuss : 104, pl. 24, fig. 17.
?1874 Cytheve orvnatissima Reuss : 146, pl. 2, figs. 5, 6.
?1887 Cythere ornatissima Reuss ; Kafka : 15, fig. 30.
1963 Cythereis ovnatissima (Reuss) and subspecies ; Pokorny : 8-26, pl. 1, figs. 1-3 ; pl. 2,
fig. 1; pl. 3, fig. 3; pl. 4, figs. 1-9 ; pl. 6, figs. 1, 2, 5,6; pl. 7, fig. 3.
MATERIAL. (i) B.M.N.H., In. 53097, 53164, 53266, 53272, Ilo. 1622-25 (Rowe)
from Upper Chalk, Norwich.
REMARKS. This species has been greatly confused in the past and large number
of forms have been referred to it.

BRITISH MARINE CRETACEOUS OSTRACODA 05

Triebel (1940) figured topotypic material from the Turonian of Bohemia and
showed that forms attributed to this species by the majority of the early authors
were almost without exception quite different. Jones (1849, plate 4, figs. 11a—h)
figured a form which he referred to as Cytherevs ciliata (Reuss). In a later paper
(1870) he stated that Reuss had decided that the two species C. ciliata and
C. ornatissima were con-specific and that the latter had preference. Jones & Hinde
(1890) therefore referred to the 1849 material under C. ovnatissima (Reuss). Jones’
(1849) figured material came from the Detritus at Charing and the Gault at
Folkestone but he recorded the species from other Cretaceous horizons (Chalk marl).
The specimens figured by Williamson (1847) as Cythere echinulata were also included
by Jones & Hinde (1890) in the synonomy. Jones states that C. orvnatissima is most
abundant in the Gault Clay. Between 1849 and 1890 a wide variety of forms were
figured as C. ornatissima (Reuss) and in 1890 Jones & Hinde separated off five
subspecies leaving Jones, 1849 material as C. oynatissima s.s._ A form previously
described by Jones (1849, pl. 5, figs. 13a-d) as Cythereis cornuta (Roemer) was
included as a subspecies under the name Cytherets ornatissima nuda. Later work,
particularly by Triebel (1940) has separated off many of those later forms, refiguring
some and erecting new species for others. Jones and Jones & Hinde’s specimens
belong to a wide range of forms but lack of material makes the bulk of the varieties
questionable.

Dr. Triebel of the Senckenberg Museum, Frankfurt am Main, has kindly sent me
a topotypic specimen of his 1940 published material. On examination it was found
that though none of the figured specimens attributed to this form by Jones belongs
there, some of the specimens from the British Museum collection are comparable.
These are included in slides from the Dunstable Chalk (I. 2466, Io. 388, Io. 1626) and
from the Upper Chalk of Keady Hill, N. Ireland (Io. 375). Triebel’s specimens have
now been referred to Cythereis longaeva longaeva by Pokorny (1963). A number of
specimens from the Rowe Norwich collections are larger and more spinose than
Triebel’s and probably belong to Cythereis ornatissima s.l. They are in slides
B.M.N.H., In. 53097, 53164, 53266, 53272 and Io. 1622-25. Further study of the
distribution in these and related forms throughout the Chalk are required before a
final decision can be made.

All the species of Cythereis from the British Upper Cretaceous show a wide
variability of ornament ; particularly is the emphasis of the reticulation and
spination. A thorough investigation of large numbers of specimens to determine
the variability of the ornament is needed in most cases. Recently Pokorny (1963),
working with topotypic material and some of Reuss’ original material now deposited
in the Natural History Museum, Vienna, has completely revised Cytherets ornatissima
(Reuss) erecting two new species and three subspecies. The limited nature of this
latter material does not entirely clarify the situation and in his opinion the two forms
C. ornatissima and C. ciliata are by no means definitely conspecific. The wide
variety of forms grouped by Reuss into C. ornatissima show that a large number of
specimens are necessary for accurate study and the limited material of Jones is hard
to place into Pokorny’s excellent systematic divisions. Triebel’s specimen (PI. 8.

66 BRITISH MARINE CRETACEOUS OSTRACODA

fig. 5) is certainly C. longaeva longaeva and the Jones material from Dunstable and
Keady Hill (Pl. 7, fig. 12, Pl. 8, fig. 3) seems closest to that form. Rowe’s specimens
are closest to C. ornatissima altinodosa in lacking surface reticulation and matching
well in the tuberculation and ribbing.

Cythereis ornatissima paupera Jones & Hinde
1890 Cytheveis ovnatissima paupera Jones & Hinde : 23, pl. 2, figs. 10, 11.

REMARKS. There is no trace of the figured material for this variety. The two
slides of material from Dunstable in the Jones (1890) collection do not appear to
resemble the figured specimens. These slides (B.M.N.H., I. 2466 and Io. 388)
contain specimens of Cythereis ornatissima (Reuss) together with Cythereis glabrella
Triebel. From the figure C. ovnatissima paupera appears to be similar to Cytherets
nuda or Cythereis lurmannae and possibly it is conspecific with one of these forms.
The spinose outline makes it unlikely that this species could be C. glabrella
and the absence of surface reticulation distinguishes it from C. ovnatissima s.s.

Cythereis ornatissima radiata Jones & Hinde
1890 Cythereis ornatissima vadiata Jones & Hinde : 25, pl. 4, fig. 13.

ReEMARKS. There is no trace of Jones’ original specimen of this form nor is there
any comparable material from the Cambridge Greensand. From an inspection of
residues from the Cambridge Greensand (Barrington) I have found no form re-
sembling the figure. The Mockler collection (1909 ; B.M.N.H.) of ostracoda from
the Cambridge Greensand contains a number of slides labelled C. ornatissima (Reuss).
These slides (B.M.N.H., In. 53344-56) contain a wide variety of forms : Cythereis
veticulata (Jones & Hinde), C. lwymannae Triebel, C. thorenensis Triebel, C. folkstonen-
sis, C. bonnemai Triebel, [socythereis fortinodis Triebel and Veenta harrisiana (Jones).
From Jones & Hinde’s figure it seems likely that C. ornatissima radiata is a worn
C. thorenensis.

Cythereis lurmannae Triebel
(Pl. 8, figs. 11-15)
1890 Cythereis ornatissima vax. stvicta Jones & Hinde : 25, pl. 1, fig. 63.
1940 Cythereis lurmannae Triebel : 201, pl. 6, figs. 63-66.
1956 Cythereis luvmannae Triebel ; Deroo : 1510.

MATERIAL. (i) B.M.N.H., Io. 346 (Jones & Hinde 1890) from the Chalk marl at
Didcot. (ii) B.M.N.H., In. 39007-08 figured Jones (1849; C. ciliata Pl. 4,
figs. 11g, g’) from the Gault at Folkestone. (i) B.M.N.H., In. 51686-88 figured
Jones (1849 ; C. cornuta pl. 5, figs. 13c, d) from the Detritus at Charing. (iv)
B.M.N.H., Io. 1194, lo. 1629-33, from the Upper Gault at Barrington, Cambs.

RemMARKS. The single figured specimen of Jones & Hinde (1890) is not identified
as such but a slide in the Jones collection from Didcot (B.M.N.H., Io. 346) appears to
contain this or a strictly comparable form together with three C. thorenensis Triebel
and one C. reticulata Jones & Hinde. The specimen is now found to belong to

BRITISH MARINE CRETACEOUS OSTRACODA 07

Cythereis lurmannae Triebel. Jones, however, has figured C. stricta in so many
different contexts that Triebel’s name is much better upheld, particularly as Jones
described the specimen as a variety and not a subspecies. The specimen labelled
by Chapman (1893) as C. stricta (B.M.N.H., I. 2687) belongs to Cythereis bonnemai
Tniebel.

Cythereis nuda Jones & Hinde
(Wedh, 7, 11S, bers, ane, 3d5))
1849 Cythere (Cythereis) lonsdaleiana Jones : 20, pl. 5, fig. 12¢ (non fig. 12a, b).
1849 Cythereis covnuta (Roemer) ; Jones : 21, pl. 5, fig. 13b (non figs. 13a, c, d).
1849 Cythereis ciliata (Reuss) ; Jones: pl. 2, fig. 11h’.
1890 Cythereis ornatissima nuda Jones & Hinde : 23, pl. 2, fig. 9 (nom figs. 8, 12-14).
1893 Cythereis wrighttt Jones & Hinde ; Chapman : 370.
1898 Cythereis ovnatissima nuda Jones & Hinde ; Chapman : 339.
21956 Cythereis nuda Jones & Hinde ; Deroo : 1519, pl. 4, figs. 62-64.

LectotyPe. B.M.N.H., In. 51685 figured Jones (1849, pl. 5, fig. 13) from the
Detritus at Charing, here designated.

Remarks. As the bulk of the specimens previously referred to C. ornatissima
nuda can be attributed to well known species, the remaining specimen (B.M.N.H.,
In. 51685) is taken as lectotype of Cythereis nuda.

The additional material figured by Jones & Hinde (1890, pl. 1, fig. 76; pl. 4,
fig. 14) appears to be lost and cannot, therefore, be determined.

A specimen attributed to Jones and labelled var. nuda from Keady Hill (B.M.N.H.,
Io. 376), differs considerably from the earlier forms, belonging either to a new
species of Cythereis or to C. wrighttt Jones & Hinde. A specimen in the Chapman
collection from the Gault at Folkestone (B.M.N.H., I. 2685) is a young form of
C. reticulata but the form described by Chapman (1898) from the Cambridge
Greensand is a true C. nuda (Sedgwick Museum B.40597). Further specimens of
C. nuda are those mentioned by Chapman (1893) as Cythereis wrightit Jones & Hinde
from the phosphatic Chalk at Taplow, B.M.N.H., I. 2607. True C. wrightit was
described from Keady Hill (Wright collection) and appears to approximate to the
form described as C. ornatissima nuda, slide B.M.N.H., Io. 376 (see above), the figure,
however, is that of a right valve whilst the British Museum specimen is a left valve.
The absence of the figured specimen precludes further study of that species. The
form described by Chapman & Sherborn (1893 (pl. 14, fig. 9) as C. wrightii var.
aculeata (B.M.N.H., I. 2707) is a pre-adult of Cythereis reticulata Jones & Hinde.

Jones’ specimen of Cythereis lonsdaletana, B.M.N.H., In. 39013 (pl. 5, fig. 12c)
from the Upper Chalk of Norwich is also Cythereis nuda.

Cythereis reticulata Jones & Hinde
(Pl. 8, figs. 16-19)
1890 Cythereis ornatissima reticulata Jones & Hinde : 24, pl. 1, fig. 68, ; pl. 4, figs. 9-12.
1940 Cythereis reticulata Jones & Hinde ; Triebel : 192, pl. 5, figs. 51-56.
1950 Cythereis reticulata Jones & Hinde ; Deroo : 1518, pl. 5, figs. 68-82.
MATERIAL. (i) B.M.N.H., Io. 1195, Io. 1634-37, from the Lower Gault Clay,
Culham, Oxfordshire.

68 BRITISH MARINE CRETACEOUS OSTRACODA

REMARKS. There is no trace of the figured material of this form. The only
labelled specimen in the Jones collection is one from Keady Hill (not among his
original localities) which is now seen to be of C. ornatissima s.l. Subsequent
authors (Triebel, Deroo) have established the true nature of the species by reference
to Albian forms which have the median longitudinal rib well developed. Of Jones’
figures, pl. 1, fig. 68 and pl. 4, figs. 9-12 fit the species best in its now accepted sense.
Such specimens are found commonly in the Gault Clay from which Jones inspected
material and the species is now restricted to forms of Albian and Cenomanian age.
References to the species from higher horizons are most likely to be of C. ornatissima
s.s. Two slides from the Chapman (1893) collection from the Gault Clay Folkestone
(B.M.N.H., I. 2686, I. 2684) contain Cythereis thorenensis Triebel. The records by
Chapman (1893, 1898) and by Weber (1934) do not belong to C. reticulata. Cythereis
hirsuta described by Damotte & Grosdidier (1963) is very similar to C. reticulata but
differs in the prominence of the median rib and muscle node in the latter. The
spination of the ribs is most pronounced in the former.

Cythereis thorenensis Triebel
(PIS tesa Aes) 7)
1849 Cythereis ciliata (Reuss) ; Jones : 19, pl. 2, figs. 11a—f (non figs. 11g, h).
1870 Cythereis ornatissima (Reuss) ; Jones : 75.
1890 Cythereis ornatissima (Reuss) ; Jones & Hinde : 21, pl. 2, figs. 1-5.
1940 Cythereis thovenensis Triebel : 195, pl. 5, figs. 57-59.

MATERIAL. (i) B.M.N.H., In. 39001—06 figured Jones (1849, pl. 2, figs. I11a—d),
figs. I1a—e from the Detritus at Charing, fig. 11f from the Gault clay at Folkestone.
(i) B.M.N.H., Io. 1197, Io. 1619-21 from the Upper Gault at Maidstone, Kent.

REMARKS. Most of Jones’ original specimens attributed to C. ornatissima from
the Gault Clay and Detritus (Albian—Cenomanian) belong to Triebel’s species.

Genus PLATYCYTHEREIS Triebel 1940
Platycythereis gaultina (Jones)
(Pl. 8, fig. 9)

1849 Cythere (Cythereis) gaultina Jones : 17, pl. 2, figs. 7a-c.
1870 Cytheve gaultina Jones ; Jones : 75, 76.
1890 Cytheve gaultina Jones ; Jones & Hinde : 18, pl. 1, figs. 35, 36.
1893 Cythere gaultina Jones ; Chapman & Sherborn : 346.
1893 Cythereis excavata Chapman & Sherborn : 348, pl. 14, fig. 8.
1898 Cytherve gaultina Jones ; Chapman : 336.
1940 Platycythereis gaultina (Jones) Triebel : 219, pl. 7, figs. 81-85 ; pl. 8, figs. 86, 87.
1956 Platycythereis gaultina (Jones) ; Mertens : 209, pl. 11, figs. 59, 60.

D1aGNosis. Small Platycythereis with strongly reticulate lateral surface.
Complex anterior marginal rib but no longitudinal ribs. Hook-like process present
over region of muscle scars.

LectotyreE. B.M.N.H., In. 52631 figured Jones (1849, pl. 2, fig. 7a) from the
Gault Clay at Folkestone, here designated.

BRITISH MARINE CRETACEOUS OSTRACODA 69

OTHER MATERIAL. (i) B.M.N.H., In. 52632 and In. 51664 figured Jones (1849,
pl. 2, figs. 7b, c) from the Gault Clay at Folkestone. (ii) B.M.N.H., I. 2688, I. 2706
(Chapman & Sherborn 1893 ; latter figured pl. 14, fig. 8). Gault Clay, Folkestone.

REMARKS. This well known species occurs throughout the Albian. No
description further to that of Triebel (1940) is required. The form figured by
Chapman & Sherborn (1893) as Cythereis excavata is conspecific with P. gaultina and
is therefore included in the synonymy. The specimen figured by Chapman (1808,
text-figs. 2a, b) which has been taken as a typical P. excavata by later authors
(Triebel 1940) differs fundamentally from the initial figures and is renamed below.

Platycythereis chapmani nom. nov.
(PI. 6; figs: 16, 18, 20)

1898 Cythere gaultina excavata (Chapman & Sherborn) ; Chapman : 336, text-figs. 2a, b.
1898 Cythere subtuberculata Chapman : 337, text-figs. 3a, b.
1940 Platycythereis excavata (Chapman & Sherborn) ; Triebel : 315, pl. 7, figs. 78-80 ; pl. Io,

fig. 110.

DiacGnosis. Large Platycythereis with prominent keel-like anterior marginal rib
joined dorsally to the eye tubercle and ventrally to the ventral longitudinal rib.
Lateral surface compressed and strongly reticulate.

HoLotyrPe. A right valve, Sedgwick Museum B4o6109, figured Chapman (1808,
Text-figs. 2a, b) from the Cambridge Greensand of Swaffham, Cambs.

OTHER MATERIAL. (i) S.M.B. 40620 figured Chapman (1808, text-figs. 3a, b)
from Swaffham. (ii) B.M.N.H., Io. 1201, Io. 1612-13 from the Cambridge
Greensand at Barrington, Cambs.

Remarks. As the initial specimens attributed to this species now prove to be
wrongly identified a new name is required for the later forms. Chapman’s (1898)
later figured specimen is taken as holotype. Due to the rarity of the species at
Swaffham, Chapman evidently did not recognise the form he figured as
C. subtuberculata to be merely an instar of P. chapman. P. chapmani is very
similar to P. laminata Triebel, figures of which are included here for comparison.
The major differences are that in P. Jaminata there is no rib along the ventral surface
and the anterior marginal rib is not as distinct and is not continued antero-dorsally
to join the eye tubercle. P. Jaminata is more triangular in shape, particularly the
left valve ; the dorsal marginal rib is also strongly developed.

Platycythereis laminata Triebel
(Pl. 6, fig. x9)
1940 Platycythereis laminata Triebel : 217, pl. 8, figs. 88-90.
1956 Platycythereis laminata Triebel ; Deroo : 1520.

MaTERIAL. B.M.N.H., Io. 1198 and Io. 1611 from the Lower Gault at Henfield,
Sussex.

70 BRITISH MARINE CRETACEOUS OST RACODA

Genus TRACHYLEBERIDEA Bowen 1953
Trachyleberidea acutiloba (Marsson)
(BIS Sriligsw75eCunkO)
1880 Cythere acutiloba Marsson : 42, pl. 3, fig. 11.
1890 Cythereis spinicaudata Jones & Hinde : 28, pl. 2, figs. 17, 18.
1940 Cythereis acutiloba (Marsson) Bonnema : 132, pl. 4, figs. 59—66.

MATERIAL. (i) B.M.N.H., I. 2487 figured Jones & Hinde (1890, pl. 2, fig. 17)
from the Upper Chalk, Keady Hill. (1) B.M.N.H., Io. 359, Ilo. 1627-28 (Jones &
Hinde 1890) from the Chalk Rock, Dunstable. (iii) B.M.N.H., lo. 1209, from the
Upper Chalk, coranguinum Zone, Sonning.

MEASUREMENTS. Length Height

Left valve (B.M.N.H., I: 2487). : . 0°65 mm. 0-35 mm.

Remarks. As suggested by Bonnema (1940) Jones & Hinde’s specimens appear
to be conspecific with Marsson’s. The shape and internal features of the species,
however, fall within Haskin’s (1963) redefinition of the genus Tvachyleberidea.

The strongly convergent dorsal and ventral margins and lateral compression are
the most distinct features of the species. The strong reticulation, weak dorsal,
ventral and anterior marginal ribs together with the low muscle node are also well
seen. The hinge is strongly amphidont, having the anterior tooth smooth and the
posterior tooth divided in the right valve.

Suborder PLATYCOPINA
Family CYTHERELLIDAE
Genus CYTHERELLOIDEA Alexander 1929
Cytherelloidea chapmani (Jones & Hinde)
(Pl. 9, figs. 15-19, 22)
1890 Cytherella chapmani Jones & Hinde : 49, pl. 3, fig. 70.
1893 Cytherella chapman Jones & Hinde ; Chapman & Sherborn : 340.
?1898 Cythervella chapmani Jones & Hinde ; Chapman : 345.
21956 Cytherelloidea chapmani (Jones & Hinde) Deroo : 1909.
Diacnosis. Cytherelloidea with the dorsal longitudinal rib connected to the
anterior end of the median rib.
LecToTyPeE. B.M.N.H., Io. 1641 (Chapman 1893) from the Lower Gault,
Folkestone.
OTHER MATERIAL. (i) B.M.N.H., I. 2669, I. 2671 (Chapman) from the Lower
Gault, Folkestone. (ii) B.M.N.H., Io. 1293, Io. 1642-46, from the Lower Gault,
Culham, Oxon.

MEASUREMENTS. Length Height
Left valve (B.M.N.H., lo. 1641, lectotype) . 0-52 mm. 0-29 mm.
Right valve (B.M.N.H., Io. 1642) ; . 0-60 mm. 0:37 mm.

DESCRIPTION. Carapace elongate, subrectangular in lateral view. Lateral
surface covered with a series of inflated ribs. A high, anterior marginal rib, dis-
continuous dorsally, is continued along the ventral margin as a low flat shelf. The
valves are swollen posteriorly to form large connected postero-dorsal and postero-

BRITISH MARINE CRETACEOUS OSTRACODA 71

ventral nodes. A long, high, slightly arcuate ventral longitudinal rib runs from the
postero-ventral node, whilst a short, horizontal rib runs from the postero-dorsal
node to terminate at two-thirds the valve length from the anterior margin. This
rib is connected to a low oblique dorsal rib which traverses the central part of the
dorsal margin. The dorsal rib is joined anteriorly to the anterior end of a prominent
ventrally convex median rib. This latter rib is not joined posteriorly to either of
the posterior nodes. The intercostal areas are smooth.

Remarks. The original Jones & Hinde specimen of this species is now lost so
the Chapman specimen mentioned by Jones is here erected lectotype. The lecto-
type is a juvenile and adult specimens from Culham are figured here.

C. chapmani most closely resembles C. pavawilliamsoni Kaye but differs in having
the median and dorsal ribs joined anteriorly and posteriorly. The prominent
median rib differentiates it from C. knaptonensis Kaye and C. stricta (Jones & Hinde).

Cytherelloidea globosa sp. nov.
(Pl. 9, figs. 7, 9, Io)

DiacGnosis. An inflated species of Cytherelloidea with prominent vertical median
sulcus limited laterally by longitudinal swelling.

Hototyre. B.M.N.H., Io. 1283, a right valve from the Cambridge Greensand
at Barrington, Cambs.

PaRATYPES. B.M.N.H., Io. 1284-87 from the same locality.

MEASUREMENTS. Length Height

Right valve (B.M.N.H., Io. 1283, holotype) 0:55 mm. 0:34 mm.
Left valve (B.M.N.H., Ilo. 1284, paratype) . 0-53 mm. 0-30 mm.

DEscRIPTION. Valves small, elongate, subrectangular. Dorsal and ventral
margins straight and subparallel ; anterior and posterior margins semicircular.
Lateral surface inflated but divided into two halves by a deep, prominent median
sulcus. Below the sulcus lies a large smooth elongated node. The anterior lateral
area is strongly and evenly inflated. The posterior lateral area bears two large
nodes, the dorsal one being larger and more elongate than the ventral one. The
postero-ventral node is connected by a swollen area to the postero-dorsal node but
is separated from the ventral node by a prominent depression, which runs obliquely
to join the median sulcus. In certain specimens the postero-ventral lobe is not
developed and is possibly a dimorphic feature.

REMARKS. The strong sulcus, anterior and posterior inflation and lack of well-
defined ribs distinguish this species from other described forms.

Cytherelloidea granulosa (Jones)
(PI. 9, figs. 24-26)
1849 Cytherella williamsoniana var. granulosa Jones : 31, pl. 7, fig. 267.
1880 Cytherella williamsoniana bosqueti Marsson : 33, pl. 2, figs. 8d, e.
1890 Cytherella williamsoniana var. granulosa Jones ; Jones & Hinde : 49, pl. 3, figs. 68, 69, 72.
1940 Cytherelloidea williamsoniana (Jones) ; Bonnema : 95, pl. I, figs. 44-47.

Diacnosis. Large Cytherelloidea with lateral surface covered with a series of

72 BRITISH MARINE CRETACEOUS OSTRACODA

prominent pustules. Short separate dorsal and ventral longitudinal ribs are present
but no median rib. Anterior marginal rib prominent.

Lectotype. B.M.N.H., In. 51609 figured Jones (1849, pl. 7, fig. 267) from the
Upper Chalk, Norwich.

OTHER MaTERIAL. (i) B.M.N.H., I. 2484 (Jones & Hinde 1890), Upper Chalk,
Magheramorne, Antrim. (ii) B.M.N.H., In. 53110, In. 53232, Io. 1647-48 (Rowe),
from the Upper Chalk, Norwich.

MEASUREMENTS. Length Height

Right valve (B.M.N.H., In. 51609, lectotype) 0-80 mm. 0-45 mm.

DeEscRIPTION. Valves quadrangular in shape with straight parallel dorsal and
ventral margins and semicircular anterior and posterior margins. A high, semi-
circular anterior marginal rib occurs which is often connected to a postero-ventral
node by a flattened marginal shelf. A further large node occurs postero-dorsally
which is somewhat elongated along the dorsal margin. The two posterior nodes
are entirely separated. A low ventrally arcuate rib lies in line with the lower of
these nodes but is not connected to it. A shallow muscle pit occurs centrally with
a small culmination immediately above it on the dorsal margin. Except for the
ribs and posterior nodes the whole of the lateral surface is covered with a series of
prominent pustules.

Juveniles are fairly common and have the ribbing subdued but maintain the
strong pustulation.

REMARKS. This species, originally described as a variety of C. williamsomiana
by Jones, is characteristic of the Upper Chalk, and has not been found by the author
below the cor-anguinum Zone. The strong pustulation makes the species distinct from
others of the genus found in the Chalk. Specimens of Marsson’s C. williamsoniana
var. bosqueti from Rugen, kindly sent to the author by Dr. E. Herrig, show that
the latter is conspecific with C. granulosa.

Cythereolloidea hindei sp. nov.
(BINopstigss 45.8510)
Diacnosis. Cytherelloidea, with anterior marginal rib, ventral longitudinal rib
and lower sinuous dorsal longitudinal rib all connected.
Hototyre. B.M.N.H., Io. 1288 a right valve from the Upper Chalk at Norwich.
ParaTyPEs. B.M.N.H., Io. 1289-92, from the same locality.
OTHER MaTeERIAL. (i) B.M.N.H., Io. 344. Chalk, Colchester ; Io. 339, Chalk,
Luton. (ii) B.M.N.H., In. 53140, In. 53234. (Rowe), Upper Chalk, Norwich.
MEASUREMENTS. Length Height
Right valve (B.M.N.H., Io. 1288, holotype) 0°75 mm. 0-42 mm.
Left valve (B.M.N.H., Io. 1289, paratype) . 0-68 mm. 0°35 mm.
DEscRIPTION. Valves elongate, subrectangular in shape. Dorsal and ventral
margins straight and parallel ; anterior and posterior margins evenly rounded.
Surface ornamented by a series of inflated ribs. Two large nodes joined by a short,
high connecting rib occur posterior-dorsally and postero-ventrally. A high,
straight rib runs along the ventral margin from the postero-ventral node and is

BRITISH MARINE CRETACEOUS OSTRACODA 73

continued without a break into a prominent anterior marginal rib. A low, sinuous
rib runs along the dorsal margin being connected to the anterior marginal rib
anteriorly and weakly joined by a cross rib to the postero-dorsal node posteriorly.
A ventrally convex median rib runs below the muscle scar pit being entirely
separated both anteriorly and posteriorly. The intercostal areas are smooth. In
the larger right valves a low flattened area lies between the dorsal rib and the
margin but in both valves the ventral rib is not separated from the margin.
Remarks. This species is easily distinguished by the connection of the ventral,
anterior and dorsal ribs and the concurrence of the ventral rib and the margin.

Cytherelloidea knaptonensis Kaye
(RISO aigss 20.210)

1963 Cytherelloidea knaptonensis Kaye : 114, pl. 19, figs. 10-12.

MATERIAL. B.M.N.H., lo. 1297 from the Upper Gault at Leighton Buzzard.

REMARKS. This species occurs in the Gault Clay at various levels at Speeton,
Leighton Buzzard and Burwell. It is closely related to C. parawilliamsoniana Kaye
and C. chapmani (Jones & Hinde). It differs from them in the poor development
of the median rib.

Cytherelloidea oblinquirugata (Jones & Hinde)
(Pl. 9, figs. 12-14)
1890 Cytherella oblinquirugata Jones & Hinde : 50, pl. 3, fig. 73.
MATERIAL. B.M.N.H., Io. 1299, Io. 1638—40 from the Upper Chalk at Norwich.

MEASUREMENTS. Length Height
Adult left valve (B.M.N.H., Io. 1640) . O75 mm. 0-40 mm.
Pre adult right valve (B.M.N.H., Io. 1299) . 0-50 mm. 0-34 mm.
Pre adult left valve (B.M.N.H., Io. 1299) . 0-50 mm. 0-30 mm.

REMARKS. This species was originally erected on a juvenile specimen and
consequently requires revision. Throughout the ontogeny of this species the median
longitudinal rib becomes increasingly less prominent and at maturity is barely
discernible. Sexual dimorphism is expressed by the existence of two large nodes
postero-dorsally and postero-ventrally in the females. The characteristic flattened
shelf along the ventral margin and the sinuous nature of the dorsal rib are the most
characteristic features of the species. The ventral rib is also more strongly joined
than in related forms such as C. williamsoniana, particularly in the males and
juveniles.

Cytherelloidea parawilliamsoniana Kaye
(Pl. 9, fig. 23)
1963 Cytherelloidea pavawilliamsoniana Kaye : 115, pl. 20, figs. 22, 23.

REMARKS. This species is strongly allied to the other members of the genus
found in the Gault. It has not been found by the writer at any locality outside
Yorkshire. It differs from the other forms in having a strong median rib which is
separated anteriorly.

74 BRITISH MARINE CRETACEOUS OSTRACODA

Cytherelloidea stricta (Jones & Hinde)
(Pl. 9, figs. 1-3, 5, 6)

21847 Cytherina servata Williamson : 79, pl. 4, fig. 79.
1849 Cytherella wiliamsoniana Jones : 31, pl. 7, figs. 26a—d, g, h (non figs. 26e, f).
1890 Cytherella williamsoniana Jones ; Jones & Hinde : 48, pl. 3, figs. 57-62.
1890 Cytherella williamsoniana stricta Jones & Hinde : 48, pl. 3, fig. 71.
1893 Cytherella williamsoniana stricta Jones & Hinde ; Chapman & Sherborn : 346.
1956 Cytherelloidea stricta (Jones & Hinde) ; Deroo : 1509, pl. 1, figs. 7, 8.
1958 Cytherelloidea stvicta (Jones & Hinde) ; Howe & Laurencich : 270.
1963 Cytherelloidea stricta (Jones & Hinde) ; Kaye : 117, pl. 19, figs. 14, 15.

DraGnosis. Cytherelloidea with prominent straight dorsal and ventral longitu-
dinal ribs but no median rib. The ventral rib is separate both anteriorly and
posteriorly and set off from the margin by a shelf formed as a continuation of the
anterior marginal rib. Dorsal rib joined to postero-dorsal process.

Lectotype. B.M.N.H., In. 51604 figured Jones (1849, pl. 7, fig. 26c) Gault Clay,
Folkestone.

OTHER MATERIAL. (i) B.M.N.H., In. 51602-03, In. 51605, In. 51608, figured
Jones (1849, pl. 7, figs. 26a, 6, d, h) Gault Clay, Folkestone. (ii) B.M.N.H., I. 2762
(Chapman & Sherborn 1893), Gault Clay, Folkestone. (iii) B.M.N.H., Io. 1294,
Upper Gault, Leighton Buzzard.

MEASUREMENTS. Length Height
Carapace (B.M.N.H., In. 51604, lectotype) . 0-71 mm. 0-37 mm.
Carapace (B.M.N.H., In. 51605) ; 5 0°75 mama: 0:37 mm.
Left valve (B.M.N. ee In. 51607) ‘ 0-73 mm. 0-37 mm.

REMARKS. C. eA cpsowicead has a pareticalanlyy confused past and almost all
Cretaceous species of what is now the genus Cytherelloidea were included in it by
early authors. Jones included a variety of forms one of which pl. 7, fig. 26f, being
the only clear external illustration was proposed as lectotype by Howe & Laurencich
(1958). Unfortunately the specimen relating to this figure was lost long before
1958 and the concept of the species becomes nomina dubium being restricted to the
single figure without specimens. The specimen from fig. 26e has been separated off
into a new species by Kaye (1963) and the rest of the material, which is found to be
conspecific recognised as C. stricta (Jones & Hinde) 1890. Thus the specimens from
Jones (1849, pl. 7, figs. 26a—d, g, h) though originally defined as C. williamsoniana
must now be withdrawn from that species in its restricted sense and included in
C. stricta. Due to the absence of material from the Jones & Hinde 1890 collection
one of these specimens is here erected lectotype.

The species is rather variable in the strength but not in the distribution of the
ribbing. Sexual dimorphism is shown by greater inflation of the posterior ead of
the valves in females and such differences may have been thought to be valid
varietal differences by Jones & Hinde in their erection of var. stricta.

The most marked features of the species are the absence of a median longitudinal
rib, the long, straight dorsal rib and the short, arcuate ventral rib which is entirely
separated from the posterior nodes. The strong anterior marginal rib is continued
as a shelf along the ventral margin. The posterior margin bears a series of small

BRITISH MARINE CRETACEOUS OSTRACODA 75

tubercles.

As C, williamsoniana, which was made the type species of the genus

(Alexander 1929), is a nomina dubium it is necessary to seek I.C.Z.N. ratification of
an alternative type species for Cytherelloidea.

IV.

SUMMARY

The various species described by Jones and Chapman etc. are listed below in
tabular form together with their new classification ; of the 98 different specific
references some 55 specific names are considered valid.

JONES 1849 :

ORIGINAL IDENTIFICATION
(1) Cythere hilseana (Roemer)
(2) Cythere punctatula (Roemer)

Cythevre punctatula var. virginea
Cythere umbonata (Williamson)
Cythere baivdiana sp. nov.
Cythereis tviplicata (Roemer)
Cythereis quadrilaterata (Roemer)
Cythereis ciliata (Reuss)

)

) Cytherets corvnuta (Roemer)

) Cythereis alata (Bosquet)

) Bairdia siliqua sp. nov. .

) Bairdia siliqua var. «

) Bardia harrisiana sp. nov.

) Bairdia angusta (Munster)

) Cythereis interrupta (Bosquet)
) Cythereis gaultina sp. nov.

)
)

(20) Cythere williamsoniana var. granulosa

JONES 1870:

ORIGINAL IDENTIFICATION
(1) Cytheridea perforata (Roemer)
(2) Cytheropteron concentricum (Reuss)

(3) Cythere harvisiana sp. nov.
(4) Cythereis ovnatissima (Reuss)

JONES & HINDE 1890 :
ORIGINAL IDENTIFICATION

(1) Pontocypris trigonalis sp. nov.
(2) Pontocypris bosquetiana sp. nov.
(3) Pontocypris triquetra (Jones)

(4) Macrocypris wrightii sp. nov. .
(5) Macrocypris concinna sp. nov.
(6) Bythocypris veussiana sp. nov.
(7) Cythere harrisiana var. setosa .
(8) Cythere havvisiana var. rveticosa
(9) Cythereis auriculata (Cornuel) .

Cythereis macrophthalma (Bosquet) .

PRESENT IDENTIFICATION

. Schulevidea jonesiana (Bosquet)

Neocythere (N.) vanveeni Mertens + Neocythere
(Centrocythere) denticulata Mertens

. Neocythere (Physocythere) virginea (Jones)
. Monoceratina umbonata (Williamson)

? Macrodentina sp.

. Protocytheve lineata (Chapman & Sherborn)
. Cythereis folkstonensis nom. nov.

Cythereis thovenensis Triebel
Cythereis lonsdaleiana Jones
Cytheveis nuda Jones & Hinde

. Alatacythere robusta (Jones & Hinde)

. Macrocypris siliqua (Jones)

. Macrocypris muensteriana Jones & Hinde

. Pontocyprella harvisiana Jones

. Dolocytheridea bosquetiana (Jones & Hinde)

Veenia harrisiana (Jones)

. Platycythereis gaultina (Jones)
. Amphicytherura chelodon (Marsson)

Cytherelloidea williamsoniana (Jones) +
Cytherelloidea stricta (Jones & Hinde)
Cytherelloidea granulosa (Jones)

PRESENT IDENTIFICATION

. Schulevidea jonesiana (Bosquet)
. Neocythere (N.) vanveeni Mertens + Neocythere

(C.) denticulata Mertens
Veenia harvisiana (Jones)
Cythereis thovenensis Triebel

PRESENT IDENTIFICATION

. Eucythere trigonalis (Jones & Hinde)
. Dolocytheridea bosquetiana (Jones & Hinde)
. Dolocytheridea bosquetiana (Jones & Hinde)
. Macrocypris wrighti (Jones & Hinde)

? Macrocypris simplex Chapman

. Dolocytheridea bosquetiana (Jones & Hinde)

Veenia harvisiana (Jones)
Veenia harvisiana (Jones)
Veenia harvisiana (Jones)

) Cytherets
) Cythereis
) Cythereis
) Cythereis
) Cythereis
) Cythereis
) Cythereis
) Cythereis
) Cythereis
) Cythereis
Cythereis
Cythereis

BRITISH MARINE CRETACEOUS OSTRACODA

ornatissima paupera
ovnatissima nuda
ovnatissima reticulata
ornatissima vadiata
ornatissima stricta
wrightti sp. nov.
tubevosa sp. nov.
tuberosa var. symmetrica
icenica sp. NOv.
icenica var. quadrata
vallata sp. nov.
spinicaudata sp. nov.

No material

. Cythereis nuda Jones & Hinde (in part)
. Cythereis reticulata Jones & Hinde

? Cythereis thovenensis Triebel

. Cythereis lurmannae Triebel

Cythereis wrightit Jones & Hinde
No material

. No material
. Amphicytherura chelodon (Marsson)

No material

. No material
. Tvachyleberidea acutiloba (Marsson)
. Brachycythere ci. sphenoides (Reuss)

Cytheropteron alatum var. robusta
Cythevopteron alatum var. fortis
Cytheropteron alatum var. cornuta

. Alatacythere robusta (Jones & Hinde)
. Alatacythere vobusta (Jones & Hinde)
? Alatacythere vobusta (Jones & Hinde)
) . 2? Alatacythere robusta (Jones & Hinde)
) . Alatacythere phylloptera (Bosquet)
) . No material
) . Monoceratina montuosa (Jones & Hinde)
) Cytheropteron cuspidatum var. tricuspidata Monoceratina tricuspidata (Jones & Hinde)
) Cytheropteron pedatum (Marsson) . Monoceratina pedata pedata (Marsson)
)
)
)
)
)
)

)
)
2) Cytheropteron sphenoides (Reuss)
)
)
)

Cytheropteron hibernicum sp. nov.
Cytheropteron ? phyllopteron (Bosquet)
Cytheropteron cuspidatum sp. nov.
Cytheropteron cuspidatum var. montuosa

2) Cythevopteron pedatum salebrosa . Monoceratina pedata salebrosa (Jones & Hinde)
Cytheropteron umbonatum acanthoptera . Monocervatina umbonatoides nom. nov.
Cytheropteron umbonatum longispina . Monoceratina umbonata (Williamson)
Cytheropteron sherbovm sp. nov. . Monoceratina sherborm (Jones & Hinde)
Cytherella williamsoniana chapmani sp. nov. Cytherelloidea chapmani (Jones & Hinde)
Cytherelloidea oblinquirugata (Jones & Hinde)

CHAPMAN & SHERBORN 1893:
ORIGINAL IDENTIFICATION
(1) Cythere ? spinifera sp. nov.
(2) Cythereis triplicata lineata
(3) Cythereis vudispinata sp. nov.
(4) Cythereis wrightii aculeata
(5) Cytheridea votundata sp. nov. .
(6) Cythereis excavata sp. nov.
(7) Cytheridea perforata var. insignis
(8) Cythere koninckiana (Bosquet)
(9) Pseudocythere simplex (Jones & Hinde)

CHAPMAN 1808:
ORIGINAL IDENTIFICATION
(1) Macrocypris simplex sp. nov.
(2) Cythere gaultina var. excavata
(3) Cythere subtuberculata sp. nov. .

OTHER COMPARATIVE SPECIES:
ORIGINAL IDENTIFICATION

(1) =

(2) Cythere slavantensis Veen

(3) Cythere acanthoptera Marsson .
(4) a

PRESENT IDENTIFICATION

. Schulevidea jonesiana (Bosquet)
. Protocythere lineata (Chapman & Sherborn)
. Protocythere rudispinata (Chapman & Sherborn)

Cythereis veticulata (Jones & Hinde)

. Schuleridea jonesiana (Bosquet)
. Platycythereis gaultina (Jones)
. Schuleridea jonesiana (Bosquet)

Veenia harvisiana (Jones)
Dolocytheridea bosquetiana (Jones & Hinde)

PRESENT IDENTIFICATION
Macrocypris simplex Chapman

. Platycythereis chapmani nom. nov.
. Platycythereis chapmani nom. nov.

PRESENT IDENTIFICATION
Macrocypris exquisita sp. nov.

. Neocythere (Physocythere) virginea (Jones)
. Monoceratina acanthoptera (Marsson)

Monoceratina bonnemai sp. nov.

BRITISH MARINE CRETACEOUS OSTRACODA

Cythere longispina Bosquet
Monoceratina laevoides Bonnema
Protocythere consobrina Triebel
Protocythere jonesi Triebel
Protocythere tricostata Triebel .

(
(
(

Protocythere triebeli Deroo
Cythereis vudispinata (Chapman &
Sherborn) Triebel

(5)
(6)
(7)
(8)
(9)
Io)
II)
12)

(13) Cythere filicosta Marsson. : <
(14) Cypridina macrophthalma Bosquet .
(15) Cytherina ornatissima Reuss

(16) Platycytheveis laminata Triebel

(17) Cythere acutiloba Marsson

(18) Cythere laticvistata Bosquet

(19) Cytherelloidea knaptonensis Kaye

(20) =

(21) Cytherelloidea pavawiliamsomiana Kaye
(22) os

(23) Cytherella williamsoniana bosqueti Marsson

“I
N

. Monoceratina longispina (Bosquet)

. Monoceratina pedata laevoides Bonnema

. Protocythere consobrina Triebel

. Protocythere lineata (Chapman & Sherborn)
. Pyrotocythere tricostata Triebel

Veenia barringtonensis sp. nov.
Veenia harrisiana (Jones)

Cythereis corvrigenda nom. noy.

. Cythereis lonsdaleiana Jones

. Cythereis macrophthalma (Bosquet)
. Cythereis ornatissima (Reuss)

. Platycythereis laminata Triebel

. LTvachyleberidea acutiloba (Marsson)
. Brachycythere laticristata (Bosquet)
. Cytherelloidea knaptonensis Kaye

Cytherelloidea hinder sp. nov.

. Cytherelloidea pavawilliamsoniana Kaye

Cytherelloidea globosa sp. nov.
Cytherelloidea gvanulosa (Jones)

V. REFERENCES

ALEXANDER, C.I. 1929.

econ. Geol., Austin, 2907 : 10 pls.

137 PP.,

Ostracoda of the Cretaceous of North Texas.

Bull. Univ. Tex. Bur.

1933. Shell structure of the Ostracode genus Cythevoptevon and fossil species from the
Cretaceous of Texas. J. Paleont., Tulsa, 7 : 181-214, pls. 25-27.
1934. Ostracoda of the genera Monocevatina and Ovthonotacythere from the Cretaceous
of Texas. J. Paleont., Tulsa, 8 : 57-67, pl. 8.
ATH, A. 1850. palaeontologische Beschreibung der nachste Umgebung von
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BonneMA, J. H. 1940-41. Ostracoden aus der Kreide des Untergrundes des norddéstlichen
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pls. 1-4 ; 28: 8-10, 21-24, 26-29, 40-43, 56-60, 70-72, pls. 5-7.
BosgueEt, J. 1847. Description des Entomostracés fossiles de la Craie de Maestricht. M/ém.
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1852. Description des Entomostracés fossiles des terrain Tertiares de la France et de la
Belgique. Mém. Acad. R. Belg., Brussels, 24 : 142 pp., 6 pls.
1854. Les Crustacées fossiles du terrain Crétacé du Limbourg. Verh. comm. geol. beschr.

Kaurt. v. Nederl., Haarlem, 2 :
Butier, E. A. & Jones, D. E. 1957.
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CHAPMAN, F. 1893.
Geol. Ass. Lond., 13:
1894.
Lond., 50:

369.

677-692, pls. 33, 34.
1898. On Ostracoda from the “‘
(7) 2: 331-346.
CHAPMAN, F. & SHERBORN, C. D.
Mag., Lond. (3) 10:
CORNUEL, J. 1846.
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1848.
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1893.

The Bargate beds of Surrey and their microscopic contents.
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On the Ostracoda of the Gault at Folkestone.
345-349, pl. 1, fig. 14.

Description des Entomostracés fossiles de terrain Crétacé Inférieur du
Bull. Soc. géol. Fr.,
Description des nouveaux fossiles microscopiques du terrain Crétacé Inférieur du
Bull. Soc. géol. Fr.,

13-137, pls. I—Io.
Cretaceous Ostracoda of Prothro and Reyburns Salt

Bull. geol. Surv. La., Baton Rouge, 32 :
Note on some microscopic fossils from the chalk of Swanscombe.

I—49, pls. 1-6.
Proc

Quart. J. Geol. Soc.
Ann. Mag. Nat. Hist., London

Geol.

Paris (2) 1 : 193-205, pl. 7

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78 BRITISH MARINE CRETACEOUS OSTRACODA

Damorte, R. & GRospIDIER, E. 1963. Quelques Ostracodes du Crétacé de la Champagne
Humide. 1. Albien-Cénomanien. Rev. Micropaléont., Paris, 6 : 51-66, pls. I-31.
DeRoo, G. 1956. Etudes Critiques au sujet des Ostracodes marins du Crétacé Inférieur et.
Moyen de la Champagne Humide et du Boulonnais. ev. Inst. franc. Pétrole, Paris, 11 :
1499-1545, pls. 1-5.
Dupper, A. 1952. Uber das Cenoman in Neidersachisten Bergland. Paldont. Z., Stuttgart,
26 : 177-188, pls. 25-27.
Haskins, C. W. 1963. Revision of the ostracod genus Tvachyleberidea Bowen., Micro-
paleontology, New York, 9: 71-74, pl. 1. q
Howe, H. V. & LaAurencicH, L. 1958. Introduction to the study of Cretaceous Ostracoda.
536 pp. Baton Rouge.
Jones, T. R. 1849. <A monograph of the Entomostraca of the Cretaceous Formation of England.
40 pp., 7 pls. Palaeontogr. Soc. (Monog.), London.
1870. Notes on the Cretaceous Entomostraca. Geol. Mag. Lond., 7: 74-77.
Jones, T. R. & Hinde, G. J. 1890. A supplementary Monograph of the Cretaceous Entomostraca
of England and Ireland. 77 pp., 4 pls., Palaeontogr. Soc. (Monogr.), London.
Karka, J. 1887. Ostracoda. In Fritsch, A. Die Crustaceen des bohmischen Kreide
fovmation : 51-56, pl. 1. Prague.
Kaye, P. 1963. The ostracod genus Neocythere in the Speeton Clay, Palaeontology, Oxford,
6: 274-281, pl. 41.
—— 1963a. Species of the Ostracod Family Cytherellidae from the British Lower Cretaceous.
Senckenbergiana, Frankfurt, a. M., 44 : 109-125, pls. 18-20.
19636. The interpretation of the Mesozoic Ostracod genera of the family Cytherideidae
Sars 1925. fev. Micropaléont., Paris, 6 : 23-40, pls. 1-3.
1963c. Ostracoda of the subfamilies Protocytherinae and Trachyleberidinae from the
British Lower Cretaceous. Paldont. Z., Stuttgart, 37 : 225-238, pls. 18, Io.
—— 1964. A revision of the ostracoda from the Bargate Beds in Surrey. Palaeontology, 7:
{in Press].
ManpetstaM, M. I. 1956. Ostracoda. Jn Contributions to palaeontology. New families
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BRITISH MARINE CRETACEOUS OSTRACODA 79

1851. Die Foraminiferen und Entomostraceen des Kreidemergels von Lemberg.
Haidingers naturw. Abh., Vienna, 4 : 17-57, pls. 2-6.

1854. Beitrage zur Charakteristik der Kreideschichten in der Ostalpen. Denkschr. Akad.
Wiss- Wien, 7: 139-142, pls. 26-28.

1855. Ein Beitrag sur genaveran Kenntniss der Kreidegebilde Meklenburgs. Z. dtsch.
geol. Ges., Berlin, 7 : 261-292, pls. 8-11.

1874. Die Foraminiferen, Bryozoen und Ostracoden des Planers 3. Die Ostracoden des
sachsischen Planers Palaeontolographica, Stuttgart, 20 : 138-154, pls. 26-28.
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792-797, pl. 122.
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Zwei Neue Ostracoden-Gattungen aus der Deutschen Kreide. Senckenbergiana, Frankfurt
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Senckenbergiana, Frankfurt a. M., 20: 471-501, pls. 1-6.

1940. Die Ostracoden der Deutschen Kreide III. Cytherideinae und Cytherinae aus der
Unteren Kreide. Senckenbergiana, Frankfurt a. M., 22 : 160-227, pls. I-10.

1941. Zur Morphologie und Okologie der Fossilen Ostracoden, mit Beschreibung
einiger Neuer Gattungen und Arten. Senckenbergiana, Frankfurt a. M., 23: 294-400
pls. 1-15. ;

VEEN, J. E. 1934. Die Cypridae und Bairdiidae der Maastrichter Tuffkreide und des
Kunrader Korallenkalkles von Siid-Limburg. Natuwuvh. Maandbl., Maastricht, 23 :
88-132, pls. 1-8.
1935. Die Cytheridae der Maastrichter Tuffkreide und des Kunrader Korallenkalkes von
Siid-Limburg. I. Die Gattung Brachycythere. I1. Die Gattung Cytheridea. Natuurh.
Maandbl., Maastricht, 24 : 26-59, 83-112, pls. 1-8.
1936. Die Cytheridae der Maastrichter Tuffkreide und des Kunrader Korallenkalkes von
Sud-Limburg, III. Die Gattungen Loxoconcha, Monoceratina, Pavacytheridea, Xesteloberis,
Cytheropteron, und Cytherura. Natuurh. Maandbl., Maastricht, 25 : 21-113, pls. 1-4.
1936a. Die Cytheridae der Maastrichter Tuffreide und des Kunrader Korallenkalkes von
Siud-limburg, IV. Die Gattungen Cytheveis, Ayrchicythereis und Cytherideis. Natuurh.
Maandbl., Maastricht, 25 : 131-168, pls. 1-9.
1938. Die Ostracoden in der Tuffkreide ohne Gelbe Limonitische Farbung unter dem
Koprolithenschichten zu Slavante. Natwurh. Maandbl., Maastricht, 27 : 10-20, 23 figs.
WEBER, H. 1934. Ostracoden aus dem Hauterive von Wenden am Mittelland-Kanal.
Niedersachs. geol. Ver., Hannover, 26 : 139-149, pls. 8, 9.

Witiiamson, W. C. 1847. On some microscopical objects found in the mud of the Levant,
and other deposits ; with remarks on the mode of formation of calcareous and influsional
siliceous rocks. Tvans. Manchr. Lit. Phil. Soc., 8 : 1-128, pls. 1-4.

All specimens figured in the plates are in the collections of the British Museum (Natural History)

Jae.

Fic.

Fic.
Fic.
Fic.

Fic.
Fic.

Fic.

Fic.
Fic.
lee,

LEE,
Fic.
Fic.
Fic.
Fic.

Fia.
Fic.

IG:

Io.

18.
19.

20.

unless otherwise stated.

IPL ANIC IS, it
All figures x 50

Schulevidea jonesiana (Bosquet) : ; : 0 Pp. 45

Male right valve, lateral view. I. 2708 (Chapman & Sherborn C. perforata var.
insignis) Folkestone.
Male left valve, lectotype. a, dorsal view ; b, lateral view. In. 51637 (Jones)
Folkestone.
Female right valve. a, dorsal view ; b, lateral view. In. 51638 (Jones) Folkestone.
Male carapace, from right. In. 51640 (Jones) Charing.
Female left valve, lateral view. I. 2709 (Chapman & Sherborn C. votundata)
Folkestone.

Amphicytherura chelodon (Marsson) . : ; : Pp. 49
Left valve, lateral view. lo. 1560 Norwich.
Right valve, lateral view. lo. 1561 Norwich.

“ Cythere’’ baivdiana Jones : ‘ : : Pp. 49
Right valve, lateral view. In. 51633 (Jones) Faringdon.

Neocytheve (N.) vanveent Mertens : : é ; Pp- 47
Left valve, lateral view. In. 51643, (Jones) Folkestone.

Neocythere (Centrocytheve) denticulata Mertens. : : Pp. 47
Carapace, dorsal view. In. 51655, (Jones) Folkestone.
Right valve, lateral view. In. 51648, (Jones) Charing.
Right valve, lateral view. In. 51646, (Jones) Folkestone.

Neocytheve (Physocythere) virginea (Jones) ‘ : F p. 48
Carapace, holotype, dorsal view. In. 51656 (Jones) Gravesend.
Carapace, holotype, from left. In. 51656 (Jones) Gravesend.
Left valve, lateral view. lo. 1562 (Jones & Hinde) Mageramorne, Antrim.
Left valve, lateral view. lo. 1563 (Rowe) Norwich.
Right valve, lateral view. Io. 1564 (Rowe) Norwich.

Dolocytheridea bosquetiana (Jones & Hinde) : : : p. 46
Right valve, lateral view. Io. 1565 (authors coll.) Maidstone.
Carapace from right, lateral view. lo. 1566 (Jones & Hinde Pontocypris triquetra)
Charing.
Carapace from left, lectotype, lateral view. In. 51629 (Jones) Folkestone.

PLATE 1

Bull. B.M. (N.H.) Geol. 10,2

Fic.
Fic.
Fic.
Fic.
Fic.

Fic.

Fic.
Fic.
Fic.
Fic.
Fic.
Fic.
Fic.
Fic.

Fic.
Fic.
Fic.

Fic.
Fic.

ics Co

PLATE 2
All figures x 50

Brachycythere laticristata (Bosquet) . - : F p. 50
Adult right valve, lateral view. Io. 1567 (Rowe) Norwich.
Carapace, dorsal view. Io. 1568 (Rowe) Norwich.
Adult left valve, lateral view. Io. 1569 (Rowe) Norwich.
Adult left valve, internal view. lo. 1570 (Rowe) Norwich.
Adult right valve, dorsal view. Io. 1571 (Rowe) Norwich.

Brachycytheve cf. sphenoides (Reuss) . Pp. 50
Right valve, lateral view. Io. 1575 (Jones & Hinde) Chalk rock at Dunstable:

Alatacythere robusta (Jones & Hinde) . : ° 2 Pp. 51
Right valve, lateral view. Io. 1572 (Rowe) Norwich.
Left valve, lateral view. Io. 362 (Jones & Hinde var. robusta) Dunstable.
Left valve, lateral view. Io. 1576 (Jones & Hinde var. robusta) Dunstable.
Right valve, dorsal view. Io. 1573 (Rowe) Norwich.
Left valve, lateral view. Io. 1574 (Rowe) Norwich.
Right valve, lateral view. lo. 1577 (Jones & Hinde var. fortis) Keady Hill.
Left valve, lateral view. In. 53172 (Rowe) Norwich.
Left valve, lateral view. Io. 2207 (Jones & Hinde hibernicum) between Black Head
and Gobbins.
Carapace, dorsal view. In. 51690, (Jones pl. 5, fig. 14b) Norwich.
Left valve, lateral view. Io. 1578, (Jones & Hinde ?hibernicum) Keady Hill.
Left valve, lateral view. I. 2678 (Chapman) Folkestone.

Alatacythere ? phylloptera (Bosquet 1854) : ¢ p. 51
Left valve, lateral view. Io. 1579 (Jones & Hinde) Keady Hill,
Right valve, lateral view. Io. 1580 (Jones & Hinde) Keady Hill.

PLATE 2
L SA ee

Bull. B.M. (N.H.) Geol. 10, 2

BIG:
FIG:

Fic.

Fic.
Fic.

Fie.
Fig.

Fic.
BIG:
Fic.
res
Fic.
Fic.

Fic.
Fic.

Fic.

Own

oom

PLATE 3
All figures x 50

Monoceratina cf. longispina (Bosquet) . ‘ : : Pp. 53
Right valve (broken), lateral view. lo. 1581 Barrington.

M onoceratina acanthoptera (Marsson) . : é Pp. 52
Left valve. a, lateral view ; 0b, dorsal view. Io. 1206 omen,

Monoceratina montuosa (Jones & Hinde) 5 Pp. 53
Right valve, lectotype. a, dorsal view ; }, lateral view. I. 2478 eres. & Hinde)
Magee.

Monoceratina sherborni (Jones & Hinde) . : : Pp. 55
Left valve, lateral view. In. 53166 (Rowe) Norwich.

Monoceratina bonnemai sp. nov. F : p. 52
Right valve, holotype. a, dorsal view ; 5b, lateral view. To: 1088) Barrington.
Left valve (broken) paratype, lateral view. Io. 1171 Barrington.

Monoceratina tricuspidata (Jones & Hinde) : : ; p. 56
Left valve, lateral view. Io. 1582 Sonning.
Right valve, lectotype. a, dorsal view ; }, lateral view. Io. 1583 (Jones & Hinde)
Keady Hill.

Monoceratina pedata pedata (Marsson) » . : Pp. 54
Left valve, lateral view. Io. 1584 (Rowe) Norwich.
Left valve, dorsal view. Io. 1584 (Rowe) Norwich.
Right valve, lateral view. Io. 1586 (Rowe) Norwich.
Left valve, lateral view. Io. 1585 (Rowe) Norwich.
Right valve, lateral view. lo. 1587 (Jones & Hinde) Ballytober, Antrim.
Pre-adult right valve, lateral view. Io. 1588 (Jones & Hinde) Keady Hill.

Monoceratina pedata salebyosa (Jones & Hinde) . Pp. 54
Left valve, lectotype, lateral view. Io. 2208 (Jones & Hinde) Whiteabbey, Antrim.
Right valve, lateral view. lo. 2209 (Jones & Hinde) Whiteabbey, Antrim.

Monoceratina pedata laevoides Bonnema ‘ : : Pp. 55
Left valve, lateral view. Io. 1589 (Rowe) Norwich.

Bull. B.M. (N.H.) Geol. 10, 2

at ais ‘
oO A EE ta
wwe ;

Fic.

Fic.
Fic.
Fic.
Fic.
Fic.

FIG.
Fic.

Fic.
Fic.

Fic.
Fic.
Fic.
Fic.

ie.
Fic.

Fic.

Gass! orn fo)

13.

17.

PLATE 4
Veenia harrisiana (Jones) : : : : p. 61

Assemblage of adult and pre-adult specimens showing the variation in size and
ornament. lo. 1210 Burwell. X25.

Monocervatina umbonata (Williamson) : : : p. 56
All figures x 50
Left valve, lateral view. I. 2677 (Chapman) Folkestone.
Left valve, lateral view. In. 51601 (Jones) Charing.
Right valve, lateral view. lo. 1590 Barrington.
Carapace, dorsal view. I. 2676 (Chapman) Folkestone.
Left valve, lateral view. HU.17.C.8.1 (author’s coll., Hull University) Speeton.

Monoceratina umbonatoides nom. nov. . . E ‘ Pa 57,
All figures x 50
Right valve, lateral view. Io. 1591 Sonning.
Left valve, lateral view. Io. 1592 (Jones & Hinde) Magee.

Macrocypris muensteriana Jones & Hinde : 0 , Pp. 43
All figures x 25
Carapace, lectotype, from left. In. 51622 (Jones) Charing.
Carapace, from right. In. 51618 (Jones) Charing.

Macrocypris siliqua (Jones) : : ‘ : Pp. 43
All figures x 25
Left valve, lateral view. Io. 1593 (Jones & Hinde) Keady Hill.
Right valve, lateral view. Io. 1276 Sonning.
Carapace, lectotype, from left. In. 51617 (Jones) Charing.
Right valve, lateral view. Io. 1594 (Jones & Hinde) Keady Hill.

Macrocypris exquisita sp. nov. : 2 2 c Pp. 42
All figures x 25
Right valve, holotype, lateral view. Io. 1270 Burwell.
Carapace, paratype, dorsal view. Io. 1272 Burwell.

Macrocypris simplex Chapman ; : : : p- 44
Left valve, lateral view. Io. 1275 S. Cave, E. Yorks. X25.

Macrocypris wrighti Jones & Hinde . ‘ ; : Pp. 44
Left valve, lectotype, lateral view. Io. 1595 (Jones & Hinde) Magee, Antrim.
X25.

Bull. B.M. (N.H.) Geol. 10, 2 PLATE 4
re Tie i Nae PES 1 } LF Gy . , ‘a " 2 +

Fic.
Fic.
Fie.
BIG.
Fic.
Fic.
Fic.
Fic.

Fic.
Fic.
Ke,

Fic.
Fic.
Fic.

Fic.
Fic.

Fic.
Fic.
Fic.

CORSE ONO are

PLATE 5
All figures x 50.

Protocythere lineata (Chapman & Sherborn)

Right valve, lateral view.

Juvenile right valve, lectotype, lateral view.

Left valve, lateral view.
Left valve, lateral view.

Io. 1596 Burwell.

lo. 1597 Burwell.
In. 51665 (Jones) Charing.

Carapace, dorsal view. lo. 1598 Burwell.

Right valve, lateral view.

In. 51667 (Jones) Charing.

Juvenile right valve, lateral view. lo. 1599 Burwell.
Juvenile left valve, lateral view. lo. 1600 Burwell.

Protocythere vudispinata (Chapman & Sherborn)

Left valve, lectotype, lateral view.

Left valve lateral view.
Right valve, lateral view.

To. 1189 Henfield.
To. 1189 Henfield.

Protocythere tviplicata (Roemer)

Right valve, lateral view.
Left valve, lateral view.

Right valve, internal view. HU.16.C.16.1 (author’s coll.) Speeton.

Io. 1601 Speeton.
Io. 1602 Speeton.

Protocythere tricostata Triebel

Left valve, lateral view.

Right valve, lateral view. HU.17.C.3.2 (author’s coll.) Speeton.

HU.17.C.3.3 (author’s coll.)

Protocytheve consobrina Triebel

Right valve, lateral view.

Io. 1603 Culham.

Juvenile right valve, lateral view. Io. 1604 Culham.

Left valve, lateral view.

To. 1605 Culham.

I. 2705 (Chapman) Folkestone.

Speeton.

p. 58

I. 2704 (Chapman) Folkestone.

Pp. 59

p. 58

Pp. 59

P. 57

Bull. B.M. (N.H.) Geol. 10, 2 PLATE 5

Fic.
Fic.
Fic.

Fic.
Fic.
Fic.
Fic.

Fic.
Fic.
Fic.

Fic.

Fic.
Fic.
Fic.
Fic.
Fic.

Fic.
Fic.
Fic.

Fic.

WN H

SY Otrcs

PLATE 6
All figures x 50.

Veenia barringtonensis sp. nov. : ‘ ° a p. 60
Male left valve, paratype, lateral view. Io. 1173 Barrington.
Female right valve, paratype. a, dorsal view ; 8, lateral view. Io. 1175 Barrington.
Female left valve, holotype. a, lateral view ; b, internal view. Io. 1172 Barrington.

Veenia harrisiana (Jones) : : ; : p. 61
Adult male carapace, dorsal view. Io. 1606 Speeton.
Adult male left valve, dorsal view. Io. 1607 Speeton.
Adult male right valve, dorsal view. Io. 1608 Speeton.
Pre-adult right valve, lateral view. I. 2703 (Chapman & Sherborn Cytheve
lineatopunctata) Folkestone.
Adult male left valve, lateral view. Io. 1609 Speeton.
Pre-adult right valve, lectotype, lateral view. In. 51663 (Jones) Folkestone.
Pre-adult right valve, lateral view. Io. 1610 (Chapman & Sherborn var. setosa)
Folkestone.
Pre-adult left valve, lateral view. I. 2691 (Chapman & Sherborn) Folkestone.

Cythereis macrophthalma (Bosquet) . ; p. 64
Female left valve, lateral view. Io. 345 (Jones & Hinde) Galehesicn
Male carapace, dorsal view. Io. 345 (Jones & Hinde) Colchester.
Male right valve, lateral view. Io. 351 (Jones & Hinde) Norwich.
Female left valve, internal view. Io. 1193 Norwich.
Male right valve, internal view. Io. 1193 Norwich.

Platycythereis chapmani nom. nov. . p. 69
Right valve, lectotype, lateral view. B.40619 (Chapman 1898) Scale.
Right valve, lateral view. lo. 1612 Barrington.
Left valve, lateral view. Io. 1613 Barrington.

Platycythereis laminata Triebel : : : : p. 69
Left valve, lateral view. Io. 1611 Henfield.

PLATE 6

Bull. B.M. (N.H.) Geol. 10, 2

Fic.
Fic.
Fic.
PIG.
Fic.

Fic.
Fic.

Fic.
ley

Fic.

Fic.
Fic.
Fic.

Fic.

FIG.
Fic.
Fic.

nPwWNH

I2.

14.
15.
7s

PLATE 7
All figures x 50.

Cythereis folkestonensis nom, nov.

Male left valve, lectotype, lateral view. In. 51678 (Jones) Folkestone.

Male right valve, lateral view. In. 51679 (Jones) Folkestone.
Female right valve, internal view. Io. 1614 Burwell.

Male carapace, dorsal view. In. 51683 (Jones) Folkestone.
Female left valve, internal view. lo. 1615 Burwell.

Cythereis covvigenda nom. nov.
Male right valve, lateral view. Io. 1616 Culham.
Male left valve, lateral view. lo. 1617 Culham.

Cythereis lonsdaleiana Jones
Left valve, lateral view. Io. 1618 Norwich.
Right valve, lectotype, lateral view. In. 39012 (Jones) Norwich.

Cythereis ? wrightit Jones & Hinde

Left valve, lateral view. Io. 376 (Jones & Hinde var. nuda) ikeady Hill.

Cythereis nuda Jones & Hinde :
Carapace from left. B.40597 (Chapman 1898) Swaffham.
Left valve, lectotype. In. 51685 (Jones) Charing.
Carapace, dorsal view. B.40597 (Chapman 1898) Swaffham.

Cythereis longaeva longaeva Pokorny
Left valve, lateral view. Io. 375 (Jones & Hinde) Keady Hill.

Cythereis thorenensis Triebel
Pre-adult, right valve, lateral view. Io. 1619 Maidstone.
Adult, right valve, lateral view. Io. 1620 Maidstone.
Adult, left valve, lateral view. lo. 1621 Maidstone.

. 63

. 62

. 63

p. 67

. 67

. 64

. 67

Bull. B.M. (N.H.) Geol. 10, 2 PLATE 7

Fic.
Fic.
Fic.
Fic.

Fic.
Fic.

Fic.
Fic.
Fic.

Fic.

Fic.
Fic.
Fic.
Fic.
Fic.

Fic.
Fic.
Fic.
1iey

OF NH

Io.

PLATE 8
All figures x 50.

Cythereis ornatissima (Reuss) : ; ¢ : p. 64
Adult left valve, lateral view. Io. 1622 (Rowe) Norwich)
Adult right valve, lateral view. Io. 1623 (Rowe) Norwich.
Adult left valve, internal view. lo. 1624 (Rowe) Norwich.
Adult right valve, internal view. Io. 1625 (Rowe) Norwich.

Cythereis longaeva longaeva Pokorny . c : p. 64
Left valve lateral view. Io. 1626 (Jones & Hinde) Dunstable:
Right valve, lateral view. (Triebel) Kostice, Bohemia (author’s collection).

Tvachyleberidea acutiloba (Marsson) . : é p. 70
Right valve, lateral view. Io. 1627 (Jones & Hinde) Duceeinle:
Left valve. a, lateral view ; b, internal view. I. 2487 (Jones & Hinde) Keady Hill.
Carapace, dorsal view. lo. 1628 (Jones & Hinde) Dunstable.

Platycythereis gaultina (Jones) ‘ ‘ p. 68
Lectotype, right valve, lateral view. In. 52631 (Jones) elkestous,

Cythereis luymannae Triebel 6 : : : p. 66
Male carapace, dorsal view. Io. 1629, Barrington.
Male left valve, lateral view. Io. 1630, Barrington.
Female left valve, lateral view. Io. 1631, Barrington.
Male right valve, lateral view. Io. 1632, Barrington.
Male right valve, lateral view. Io. 1633 (Jones & Hinde C. stricta) Didcot.

Cythereis reticulata (Jones & Hinde) . : 6 3 p. 67
Left valve, dorsal view. Io. 1634, Culham.
Left valve, lateral view. Io. 1635, Culham.
Carapace, dorsal view. lo. 1636, Culham.
Right valve, lateral view. lo. 1637, Culham.

PLATE 8

Bull. B.M. (N.H.) Geol. 10, 2

Fic.
Fic.
Fic.
Fic.
Fic.

Fic.
Fic.
Fic.

Fic.
Fic.
Fic.
Fic.
Fic.
Fig.

Fic.
Fic.

Fic.

Fic.
Fic.
nee

DAunw nd H

24.

26.

PLATE 9
All figures x 50.

Cytherelloidea stricta (Jones & Hinde) 8 :
Male carapace, lectotype, from right. In. 51604 (Jones) Folkestone.
Male right valve, lateral view. lo. 2212 Leighton Buzzard.
Female carapace from right, lateral view. In. 51605 (Jones) Charing.
Male left valve, lateral view. lo. 2213 Leighton Buzzard.
Female right valve, lateral view. Io. 2214 Leighton Buzzard.

Cytherelloidea hindei sp. nov. :
Right valve. holotype, dorsal view. lo. 1288 Norwich.
Left valve, paratype, lateral view. lo. 1289 Norwich.
Right valve, holotype, lateral view. Jo. 1288 Norwich.

Cytherelloidea globosa sp. nov.
Right valve, holotype, dorsal view. lo. 1283 Barrington.
Right valve, holotyp’, lateral view. Io. 1283 Barrington.
Left valve, paratype, lateral view. lo. 1284 Barrington.

Cythevelloidea oblinquivugata (Jones & Hinde)
Right valve, juvenile, lateral view. 1o.1638 Norwich.
Left valve, juvenile, lateral view. Io. 1639 Norwich.
Left valve, adult, lateral view. Io. 1640 Norwich.

Cytherelloidea chapmani (Jones & Hinde)
Right valve, adult, lateral view. Io. 1642 Culham.

Left valve, pre-adult, lectotype, lateral view. lo. 1641 (Chapman) Folkestone.

Right valve, adult, dorsal view. Io.1643 Culham.
Right valve, pre-adult, lateral view. Io. 1644 Culham.
Left valve, adult, lateral view. Io. 1645 Culham.

Left valve, juvenile, lateral view. Io. 1646 Culham.

Cytherelloidea knaptonensis Kaye
Left valve, paratype, lateral view. Hull University.20.c.19.1 Sse,
Left valve, holotype, lateral view. Hull University.20.c.18.1 Speeton.

Cytherelloidea pavawilliamsoniana Kaye

Right valve, holotype, lateral view. Hull University.20.c.23.1 Speeton.

Cytherelloidea granulosa (Jones)
Right valve, lateral view. Io. 1647 (Rowe) Norwich.
Right valve, lectotype, lateral view. In. 51609 (Jones) Norwich.
Left valve, lateral view. Io. 1648 (Rowe) Norwich.

2 GP

5 Hp

- 73

7°

as)

- 73

5 Gi

PLATE 9

Bull. B.M. (N.H.) Geol. 10, 2

TWO HETEROSPOROUS PLANTS
FROM THE UPPER DEVONIAN OF
NORTH AMERICA

J. M. PETTITT

BULLETIN OF

_ THE BRITISH MUSEUM (NATURAL HISTORY)
GEOLOGY | Vol. 10 No. 3

Cu
a
i

LONDON : 1965

TWO HETEROSPOROUS PLANTS
FROM THE UPPER DEVONIAN OF
NORTH AMERICA

Pp. 81-92 ; 2 Plates ; 1 Text-figure

BULLETIN OF
THE BRITISH MUSEUM (NATURAL HISTORY)
GEOLOGY Vol. 10 No. 3
LONDON : 1965

THE BULLETIN OF THE BRITISH MUSEUM
(NATURAL HISTORY), instituted in 1949, 1s
issued 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.

This paper is Vol. 10, No. 3 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)

Issued February, 1965 Price Thirteen Shillings

iy O ER ER@SPOROUS EE ANAS
FROM) riE UPPER DEVONIANOEF

NORTH AMERICA
By J. M. PETTITT

I SYNOPSIS

The sporangia and spores of two heterosporous plants, Barinophyton rvichardsoni and
Archaeopteris cf. jacksoni from the Upper Devonian of North America are described. The
sporangial remains of the latter are compared with those of Archaeopteris latifolia from the
Upper Devonian of Pennsylvania, and the spores of both genera are compared with Devonian
dispersed spores. A reconstruction of part of a fertile branch of Barinophyton is presented.

Il INTRODUCTION

THE plants described in this paper are compression fossils from the Upper Devonian
of North America. The specimen of Barvinophyton richardsoni from Perry, Maine,
was probably collected by Sir William Dawson in the early 1860s, and the specimens
of Archaeopteris cf. jacksom were collected by W. Graham-Smith from Scaumenac
Bay, Quebec, in 1937. All the specimens are in the collections of the Department
of Palaeontology, British Museum (Natural History).

I should like to express my thanks to Dr. John Richardson, to Professor C. A.
Arnold, to Professor H. P. Banks and especially to Dr. W. G. Chaloner for much
helpful advice and discussion during the course of this work. Thanks are also due
to Mr. J. V. Brown for taking some of the photographs on Plates 1 and 2.

III SYSTEMATIC DESCRIPTIONS
PTERIDOPHYTA
Genus BARINOPHYTON White

Barinophyton richardsoni (Dawson)
(Elsieticss 76.00) ble 2, fig. 2. Text-fiewn)

DESCRIPTION. The specimen (part and counterpart) of Barinophyton richardsoni
examined is a compression fossil consisting of poorly preserved fertile spikes or
branches slightly more than 2 cm. in length which are probably incomplete.

Arising from the surface of the axis are appendages and sporangia arranged in
two longitudinal rows. The spikes are lying on the bedding plane with their
supposed dorsal surfaces uppermost (PI. 1, figs. 7,8). The arrangement of the fertile
parts is very much like that described by Arnold (1939) for Barinophyton citrulliforme
Arnold and the orientation of the specimen is based on that proposed by Arnold.
The compressed sporangia and appendages form oval to elongate carbonaceous
masses, about 2-3 mm. in length and 1 mm. in width, on each side of the axis.
In the majority of cases adjacent sporangia on the same side of the axis are I-2 mm.
apart, but in places they are closer together forming a more or less continuous row.

Fragments of the carbonaceous material representing the sporangia were picked
off with a needle and treated with Schulze’s solution (nitric acid and potassium
chlorate) followed by dilute ammonia. The macerated fragments were then washed

84 UPPER DEVONIAN HETEROSPOROUS PLANTS

and mounted in glycerine jelly. Slight pressure with a needle on the coverslip
completely disaggregated the mass and microspores and megaspores became dis-
cernible. Each of the twelve carbonaceous fragments from different regions of the
fructification treated in this way yielded both microspores and megaspores. Micro-
spores were released in large numbers ; a fragment about I mm. square giving
several hundred microspores, but only about five to ten megaspores.

Megaspores. A megaspore of Barinophyton richardsont is illustrated on PI. 2, fig. 2.
The spores are usually fragmentary, and only one complete specimen has been found.
They are flattened in the equatorial plane, circular to oval in outline and about
220-250u in greatest diameter. The triradiate mark is in the form of three simple
commissures which are about 20u long. The exine is 2—3y thick and at the contact
areas is darker and probably thicker than elsewhere. Most of the spores have
smooth walls, but some appear to be minutely punctate.

Devonian spores with dark contact areas have been described by Lang (1931,
1932) in the sporangia of Psilophyton from the Lower Devonian of Gaspé (Psilophyton
princeps) and from Scotland, but these spores are considerably smaller than the
megaspores of B. richardsont. Naumova (1953) has recorded two dispersed spores,
Letotriletes nigratus and Levotriletes atavus from the Middle and Upper Devonian
of the Russian Platform which have thickened contact areas, but both Naumova’s
spores are smaller than the Barinophyton megaspores. The megaspore Tvileites
langi from the Cromarty nodule beds (Achanarras horizon, Middle Old Red
Sandstone) of Scotland described by Richardson (in press) is superficially similar
to the megaspores of Barinophyton but has very much longer commissures.

Circular, trilete, thin, smooth-walled spores with short triradiate commissures
and differentiated pyramic proximal areas can be included in the genus Calamospora
Schopf, Wilson & Bentall (1944) and the inclusion of the Barinophyton megaspores
in this genus would seem appropriate.

Microspores. Specimens flattened in the equatorial plane are more or less circular
in outline and 48-62y in diameter. The triradiate mark is in the form of simple
commissures which extend for about one-half to two-thirds of the spore radius.
The outer part of the spore exine consists of a thin, highly wrinkled membrane
(Pl. 1, fig. 10). In some specimen.s this membrane has been lost and a smooth to
minutely punctate inner layer of the exine is seen. At the proximal pole, surrounding
the triradiate mark of every spore, is a darker pyramic area of the exine very similar
to that seen in the megaspores, but less distinct.

No dispersed spores have been described from the Devonian that exactly resemble
the microspores of B. richardsom. However, if found without the thin outer exinous
membrane spores of this type would probably be included in the genus Calamospora
Schopf, Wilson & Bentall.

Discussion. The generally accepted interpretation of the fructification of
Barinophyton is that of an axis having on its dorsal surface two rows of fleshy
appendages, between which the sporangia are borne {Arnold 1939). The appendages
are disc-shaped structures transversely oriented to the long axis of the fertile branch
(Text-fig. 1).

UPPER DEVONIAN HETEROSPOROUS PLANTS 85

If each carbonaceous mass between successive appendages is the remains of one
sporangium as is suggested in the descriptions of this genus by Arnold (1939) and
by Krausel & Weyland (1941) it is difficult to explain the presence of both micro-
spores and megaspores in every sporangial fragment. The possibility that the
sporangia are bisexual cannot be ruled out, but it would certainly be unusual.
The discovery by Arnold (1958) of both microspores and megaspores in a single
sporangium of a petrified Calamostachys may possibly be explained by the plane of
his section cutting through drooping sporangiophores on which the sporangia are
obliquely arranged, and by the breakdown of the walls between a microsporangium
and a megasporangium prior to fossilisation. In Arnold’s pl. ro, fig. 2 the radial
sporangial walls show an interruption where the microspore and megaspore masses
meet ; this may be the result of the plane of section passing from a microsporangium
to a megasporangium at slightly different levels, rather than a bisexual sporangium.
Mahabale (1956) reports sporangia containing both microspores and megaspores in
living and fossil Marsileaceae, but as Pant & Shrivastava (1961 : 51, footnote) point
out, Mahabale is evidently mistaking residual tapetal inclusions and abortive spores
for microspores.

In Barinophyton the occurrence of the two types of spores together can be ex-
plained if each carbonaceous mass represents the remains of one microsporangium
and one megasporangium. How these are arranged in relation to each other and
to the appendage cannot be determined from the fragmentary material upon which
this account is based, but appressed between the appendages as shown in Text-fig. 1
would seem the simplest explanation.

Fic. 1. Semi-diagrammatic reconstruction of part of a fertile branch of Barinophyton
showing the possible arrangement of appendages (A) and sporangia (S). Proximal is to
the right.

Ananiev (1954) described some plant remains from the Lower Devonian of
Torgachino, Krasnoyarsk, U.S.S.R. as Barinophyton obrutschevia but later (1957)

86 UPPER DEVONIAN HETEROSPOROUS PLANTS

made them the basis of a new genus Protobarinophyton, the organisation of the fertile
parts of which is clearly similar to that of Barinophyton. Protobarinophyton,
however, differs from Bavinophyton primarily in its dichotomous mode of branching ;
branching in Barinophyton is alternate. It is interesting to note that in his earlier
account Ananiev was disinclined to attach generic importance to this character.

Krausel & Weyland (1941) state that dichotomy of the fertile axes is known in
Barinophyton citrulliforme and in B. obscurum (Dun) White from the Upper Devonian
of New South Wales (Dun 1897), but in their respective descriptions of these plants
none of the authors concerned (Arnold 1939, Dun 1897, White 1905) mentions this.

Perhaps some significance can be attached to the fact that Protobarinophyton is
confined to the Lower Devonian whilst Bavinophyton is known from the Lower,
Middle and Upper Devonian. Arnold (1947) however, restricts the range to the
Middle and Upper Devonian. It is tempting to assume that Protobarinophyton and
Barinophyton represent stages in the phylogeny of a single line, the members of
which are dichotomously branched in the Lower Devonian and become alternately
branched higher in the succession. Unfortunately, nothing can be seen of the
branching of the Lower Devonian Barinophyton dawsont Krausel & Weyland (1941).

Ananiev (1954, 1957) has found that the primary xylem of P. obrutschevit is a
cylindrical protostele composed of annular tracheids and this is surrounded by
homogenous parenchymatous tissue, which comprises the bulk of the axis. The
anatomical structure and branching habit of the plant is therefore suggestive of a
psilopsid or lycopsid form, but in the organisation of the fructification it is quite
unlike these plants. Although Ananiev does not record the presence of spores in
the sporangia of his new genus he was able to demonstrate that the sporangia were
relatively massive organs which had a longitudinal suture for dehiscence.

The anatomy of Barinophyton is completely unknown and any detailed considera-
tions as to its true affinities will have to wait until adequate material is discovered.

Arnold (1939) has reported the occurrence of smooth-walled spores, 300—400p in
diameter, in carbonaceous remains of the sporangia of Barinophyton citrulliforme
from the Upper Devonian of Cattaraugus County, New York, which he later (1947)
judges to be megaspores. Krausel & Weyland (1941) observed an indistinct row
of four to five circular bodies, 0-1 to 0-2 mm. in diameter and of uncertain nature,
on the fertile branches of B. dawsoni. Those authors suggest that these bodies might
be either sporangia or large spores.

The present account of microspores and megaspores in B. richardsoni supports
Arnold’s conclusion that Barinophyton is heterosporous.

PROGYMNOSPERMOPSIDA Beck
ARCHAEOPTERIS Dawson
Archaeopteris cf. jacksoni (Dawson)
(Pl>x,, figs. 16,6); Pl a2 eiigd)
Arnold (1936) describes and illustrates fertile pinnae of Archaeopteris from
Scaumenac Bay, Quebec, as probably referable to Avchaeopteris jacksont. The

UPPER DEVONIAN HETEROSPOROUS PLANTS 87

fertile pinnae from the Escuminac formation of the same locality which I have
examined resemble Arnold’s material so closely that I consider that they probably
belong to the same species.

Two of the specimens (V.51312, V.51316) from which spores were obtained are
fragments of fertile pinnae (PI. 1, figs. 2, 3), one consisting of the distal ends of
two pinnae about 2 cm. long, the other of four pinnae about 2-5 to 3 cm. long.
The pinnae on each specimen are so arranged that they have obviously been part of
a parallel series on the same leaf. The third specimen (V.44711) is a large fertile
primary pinna, 24 cm. long and bearing 18 or Ig pinnae (PI. 1, fig. 1). The smaller
specimens are preserved in a very soft sandstone from which the entire spore-masses
could be dissected out with a needle. The third, more complete specimen is preserved
in a much more indurated, finer grained sandstone and the remains of the sporangia
were removed from this with cellulose nitrate film pulls. When dissected out the
spore-masses were treated with hydrofluoric acid to remove any adherent mineral
matter, individually macerated in Schulze’s solution followed by dilute ammonia
and mounted in glycerine jelly, Canada Balsam or “ Clearcol’’. The cellulose
nitrate film pulls when removed were treated with dilute hydrofluoric acid, washed
and dried, and mounted in Canada Balsam.

In the two smaller specimens, from which the most complete sporangial remains
were obtained, the sporangia are represented only by spore-masses ; no remnant of
the sporangium wall cuticle has been preserved. The macerated spore-masses are
of two kinds, both usually 0-3 to 0-5 mm. wide, but some 1-7 to 2:8 mm. long consist-
ing of several hundred microspores 45-70 in diameter and others 1:2 to 2-6 mm.
long of 9-48 (usually about 15-25) megaspores I10—370y in diameter (PI. 1, figs. 5, 6).
By teasing the spore-masses with a pair of needles the spores were separated.

Megaspores. The megaspores of Archaeopteris cf. jacksoni when flattened in the
equatorial plane are more or less circular in outline. The triradiate mark extends
between one to two-thirds of the spore radius and is either in the form of simple
commissures or laesurae with labra (lips) about 5y wide. A conspicuous inner
membrane (mesosporium?) can be seen in some spores. Paraffin sections of the
megaspore-masses (for embedding and sectioning technique see Chaloner & Pettitt
1964) cut at intervals of 6 show that the spore exine is composed of two distinct
layers ; an inner homogenous layer about 2 thick is surrounded by a granular
layer 6-7y in thickness. The exine sculpture of the spores is somewhat variable.
In some specimens the entire spore coat is evenly covered with minute rounded to
conical projections (coni) I-2u high and Ip broad at the base (PI. 2, fig. 1), whilst
in others it is unevenly covered either with elements that are more or less circular
in radial projection and about ry or less in height (grana) or with elements in which
the height (1~2y) is greater than the basal diameter and in which the upper end is
not much broader than the base (baculae). In some spores the sculptural elements
on the contact areas are rather smaller than those covering the rest of the exine,
and in others the distal limits of the contact areas are marked by weak curvaturae
formed by coalescent sculptural elements.

Megaspores with a mesosporium and a uniform decoration of coni can be included

88 UPPER DEVONIAN HETEROSPOROUS PLANTS

in the genus Brharisporites Potonié (1956), and clearly some of the Archaeopteris
megaspores could also be included in this genus. However, the variation in exine
sculpture of some of the spores makes it difficult to assign them to a single genus
based purely on morphographic characters.

Two species of Biharisporites have been described from the Upper Devonian of
Canada by Chaloner (1959) and one by McGregor (1960). One of Chaloner’s species,
B. ellesmerensis is within the size range of the Archaeopteris megaspores but differs
primarily in having considerably larger sculptural elements ; McGregor’s species
B. submamullaris is larger (280-610y).

Microspores. The equatorially flattened microspores of Archaeopteris cf. jacksont
are circular to subtriangular in outline. The triradiate mark extends over about
two-thirds of the spore radius, in some specimens nearly to the equator, and is
formed by a simple suture. The exine is about 2—4p thick and is evenly covered
with an ornament of small conical elements 1-1-5y high and Ip or less wide at the
base. In some spores an inner membrane (mesosporium?) is present (Pl. 1, fig. 9),
but in others it is not seen.

Circular miospores with an ornament of minute conical projections can be
referred to the form genus Cyclogranisporites Potonié & Kremp (1954). This genus
is ubiquitous throughout the Carboniferous, and a Lower Carboniferous form very
similar to the microspores of A. cf. jacksoni has recently been described by Playford
(1962) as Cyclogranisporites lasius. Chaloner (1963) has recorded the genus in
sediments of Lower or Middle Devonian age from Southern England.

It has proved impossible to determine the precise arrangement of the two types of
sporangia on the fertile pinnae. However, three adjacent spore-masses belonging
to the same pinnule (ringed on PI. 1, fig. 3) were dissected out and macerated. It
was found that two of the spore-masses were composed of microspores and one of
megaspores, and it seems therefore, that both microsporangia and megasporangia
are borne on the same pinnule in A. cf. jacksont.

Each of the spore-masses is enclosed in a coat of acid-resistant cutinised material
in the form of globules or as a continuous non-cellular layer adhering to the spores.
In some of the spore-masses this residue extends beyond the end of the mass and
forms a short protrusion about 60 in length which might represent the remains of
the sporangium stalk (Pl. 1, fig. 4). The coat of cutinised material is presumably
a residue of the same nature as that reported in Psilophyton sporangia by Lang
(1931) which he terms a “‘ tapetum’’, in the sporangia of Archaeopteris latifolia
by Arnold (1939), in the sporangia of Svalbardia polymorpha by Heeg (1942), and
is probably what Beck (1960) calls non-cellular reticulate thickenings in the sporangia
of Archaeopteris ci. macilenta.

Feller (1953) and Boterberg (1956) have described inclusions associated with the
formation of pseudospores during microsporogenesis in Marsilea which somewhat
resemble the globules of tapetal substance in the sporangia of Archaeopteris cf.
jacksomt. Boterberg believes that in Marsilea the pseudospores are formed from
the residual mass of plasmodial material which results from a lessening of meiotic
activity.

UPPER DEVONIAN HETEROSPOROUS PLANTS 89
COMPARISON WITH SPORANGIA OF OTHER SPECIES OF ARCHAEOPTERIS

Although heterospory has been inferred in several species of Archaeopteris (Krausel
& Weyland 1941) it has only hitherto been positively demonstrated in one,
Archaeopteris latifolia, from the Upper Devonian of Pennsylvania (Arnold 1939).
The spore-masses of A. latifolia are about as large as those of A. cf. jacksont, and
although the diameter of the megaspores in the two is very similar, the number
per spore-mass is greater in the Scaumenac species. The microspores in A. latifolia
are somewhat smaller, being only 35y in diameter. Beck (1960) has found spores
of only one size in the sporangia of A. cf. macilenta, but as he later pointed out
(Beck 1962) this could mean that the species was dioecious or bore the mega-
sporangia and microsporangia on different leaves or branches.

I have had the opportunity to examine some fertile material of A. latifolia from
the Port Allegany locality presented to the British Museum (Natural History) by
Dr. W. G. Chaloner. Due possibly to a slight difference in preservation this material
has given a certain amount of information additional to Arnold’s original account.

Arnold (1939) describes only spore-masses from his material of A. latifolia and
does not give any information about the sporangium wall. In the British Museum
material of this species, bulk maceration of the shale results in the release of
isolated, incomplete sporangium cuticles the largest measuring 2-5 mm. in length
by 0-3 mm. in width, bearing the clear impression of a cellular reticulum (PI. 2,
figs. 4, 5). The cells of the reticulum are isodiametric, measuring about 60-80u
across, and on certain of the cuticles a somewhat thinner zone of cells runs longi-
tudinally along the length of the sporangium. The cells of this thinner band are
more or less elongated, measuring 80 by 6o0u and are uniseriate (Pl. 2, fig. 5).
Although no definite dehiscence mechanism has been demonstrated in the sporangia
of Archaeopteris it has been suggested that spore release was preceded by a simple
longitudinal splitting of the sporangium wall (Beck 1960). The longitudinal band
of cells in the cuticles of A. latifolia would probably facilitate dehiscence of this type
by presenting an area of weakness along which splitting could occur.

Tapetal residues in the form of small acid-resistant cutinised globules are also
present in the sporangia of A. latifolia, and in many forms a thick covering on the
inside of the cuticle (PI. 2, fig. 8).

Adhering to the inside of most of the sporangium cuticles are more or less circular
spores 35-50u in diameter (PI. 2, fig. 7). A clear triradiate mark extends between
one-half to three-quarters of the spore radius and is formed by a simple suture.
The exine is about Ip thick and is evenly covered with small conical elements Ip
high and ty or less broad at the base. The morphology of these spores is essentially
the same as that of the microspores of A. jacksoni and consequently they could also
be referred to the genus Cyclogranisporites.

The occurrence of spores inside the sporangium cuticle is too frequent to be the
result of chance association, and several spores can be found on some of the larger
fragments of cuticle. The lower size limit of these spores corresponds to that given
by Arnold for the microspores of A. latifolia, but Arnold does not record any
sculptural elements on the exines of the microspores he isolated. Beck (1960) has

go UPPER DEVONIAN HETEROSPOROUS PLANTS

reported the occurrence of spores, 44—68y in diameter, with finely spinose exines in
the sporangia of A. cf. macilenta. To judge solely from his illustrations of these
spores (pl. 27, figs. 8, 9) they appear to be of the Cyclogranisporites type. If, as
suggested by Beck, his inability to demonstrate heterospory in A. cf. macilenta
was due to the species being dioecious, or bearing the megasporangia and micro-
sporangia on different branches or leaves, the spores described by him could be the
microspores of another heterosporous species of Avchaeopteris, and this is, as Beck
points out, a much more acceptable alternative than to consider the genus as includ-
ing both homosporous and heterosporous species.

In the material of A. latifolia from Port Allegany, none of the sporangium cuticles
which I have examined contained megaspores. However, a large number of mega-
spores was recovered from the maceration residues of the matrix. These megaspores
are more or less circular in polar view and 300—400y in diameter. The triradiate
mark extends from one-half to three-quarters of the spore radius and has lips 7u
wide. The exine is about 7-8y thick with frequent secondary folds. The orna-
mentation ranges from conical elements in which the length is more than twice
the basal diameter (spinae), to raised ridges forming an irregular reticulate sculpture
about 5u high (muri or cristae). On the contact faces of all these forms the sculptural
elements are smaller than those covering the rest of the exine. An inner membrane
(mesosporium?) can be seen in some specimens (PI. 2, fig. 6). The extremes of
variation in exine ornamentation in the megaspores makes it impossible to assign
them to any one form genus. Those forms with an ornamentation of conical
appendages could be included in the megaspore genus Biharisporites, and megaspores
of essentially this type have been found in the megasporangia of A. cf. jacksont.

The megaspores of A. latifolia described by Arnold (1939) are within the size
range of the megaspores described here, but no highly developed sculpturing is
present on his specimens, the exine being only “ slightly roughened’. _ It is possible
that the megaspores described above are those of A. latifolia and that differences
in preservation or in maceration procedure can account for the more pronounced
ornamentation in my material. However, because proof of organic connection is
lacking this suggestion is at the most very tentative, and is based merely on the
association of the spores and sporangia.

Discussion. One of the most interesting facts to emerge from the present study
of the sporangia of Avchaeopteris is the similarity of the spores in the various species.
The microspores of A. cf. jacksoni and of A. latifolia are almost identical and both
are referable to the genus Cyclogranisporites, and those of A. cf. macilenta described
by Beck (1960) are clearly similar. In addition, the megaspores of A. cf. jacksoni
and possibly those of A. latifolia are morphologically alike.

That the various species of a plant genus should have spores that are morpho-
logically similar is in no way unusual (see for example the microspores of Selaginella
eggersit and Selaginella radiata figured by Erdtman (1957, text-figs. 177, 180)).
However, spores very similar to the microspores of Archaeopteris have also been
found in some other Devonian plant genera, e.g., Sporogonites exuberans Halle
from the Lower Devonian of Réragen in Norway (Halle 1916) and Svalbardia

UPPER DEVONIAN HETEROSPOROUS PLANTS 91

polymorpha from the upper Middle Devonian or lowermost Upper Devonian of
Spitsbergen (Hgeg 1942) and would therefore be of limited taxonomic value.

IV CONCLUSIONS

The present study of the fructification of Avchaeopteris cf. jackson in which the
microsporangia and megasporangia are in organic connection further demonstrates
heterospory in this genus and supports Beck’s and Krausel & Weyland’s supposition
that, in all probability, all Avchaeopteris is heterosporous.

The occurrence of both microspores and megaspores in the sporangia of Barinophy-
ton vichardsoni demonstrates that the genus is definitely heterosporous and is the
more noteworthy for being so, as it differs conspicuously from other Devonian
heterosporous plants.

It would seem that heterospory in the Upper Devonian appeared independently
in more than one line of plants, and it has already been shown (Chaloner & Pettitt
1963, 1964) that at least one group had by that time reached a level of heterospory
that is the hallmark of the seed.

REFERENCES

Ananiev, A. R. 1954. Flore du Dévonien inférieur de la partie Sud-Est de la Sibérie
occidentale. In Pyvoblémes de la géologie de l’Asie, 1: 287-324, pls. 1-5. Akad. Nauk.
S.S.S.R., Moscow. [In Russian].

1957. Nouveaux végétaux fossiles du Dévonien inférieur de Torgachino dans la partie
Sud-Est de la Sibérie occidentale. Bot. Zh., Moscow, 42 : 691-702, pls. 1-3. [In Russian].
ARNOLD, C. A. 1936. Observations on fossil plants from the Devonian of Eastern North
America, I. Plant remains from Scaumenac Bay, Quebec. Contr. Mus. Paleont. Univ.
Mich., Ann Arbor, 5 : 37-47, pls. 1-4.

1939. Observations on fossil plants from the Devonian of Eastern North America, IV.
Plant remains from the Catskill Delta deposits of Northern Pennsylvania and Southern
New York. Contr. Mus. Paleont. Univ. Mich., Ann Arbor, 5 : 271-313, pls. 1-10.

1947. An Introduction to Paleobotony. ix+433 pp., 187 figs. New York and London.

1958. Petrified cones of the genus Calamostachys from the Carboniferous of Illinois.
Contr. Mus. Paleont. Univ. Mich., Ann Arbor, 14: 149-164, pls. I-12.

Beck, R. 1960. The identity of Avchaeopteris and Callixylon. Brittonia, N.Y.,12 : 351-368,
pls. 24-29.

1962. Reconstructions of Archaeopteris and further consideration of its phylogenetic
position. Amer. J. Bot., Lancaster, 49 : 373-382, 2 figs.

BoTERBERG, A. 1956. Etude sur les Hydroptéridales, IV. Genése et différenciation des

parois sporales chez Marsilea diffusa Lepr. Cellule, Louvain, 58 : 81~106, pls. 1-6.
CHALONER, W.G. 1959. Devonian Megaspores from Arctic Canada. Palaeontology, London,
1: 321-332, pl. 55.

1963. Early Devonian spores from a borehole in Southern England. Gyvana Palynologica,
Stockholm, 4 : 100-110, pl. I.

CHALONER, W. G. & Pettitt, J. M. 1963. A Devonian Seed Megaspore. Nature, Lond.,
198 : 808-809, 3 figs.

1964. A Seed Megaspore from the Devonian of Canada. Palaeontology, London, 7 :
(In Press).

Dun, W.S. 1897. On the Occurrence of Devonian Plant-bearing Beds on the Genoa River,
County of Auckland. Rec. Geol. Surv. N.S.W., Sydney, 5 : 117-121, pls. 10, 11.

ErpDTMAN, G. 1957. Pollen and Spore Morphology, Plant Taxonomy. Gymnospermae,
Ptevidophyta, Bryophyta. 151 pp., 265 figs. Stockholm.

g2 UPPER DEVONIAN HETEROSPOROUS PLANTS

FELLER, M. J. 1953. Etude sur les Hydroptéridales, II. Sporocarpe et sporogenése chez
Marsilea hirsuta R. Br. Cellule, Louvain, 55 : 307-377, pls. I-10.

Hare, T.G. 1916. A fossil sporogonium from the Lower Devonian of Réragen in Norway.
Bot. Notisey, Lund., 1916 : 79-81, 1 fig.

HoeEc,O.A. 1942. The Downtonian and Devonian Flora of Spitsbergen. Novges Svalbard-og-
Ishavs-Undersokelser. Skrift., Oslo, 83 : 7-228, pls. 1-57.

KRAUSEL, R. & WEYLAND, H. 1941. Pflanzenreste aus dem Devon von Nord-Amerika, II.
Die Oberdevonischen Floren von Elkins, West-Virginien, und Perry, Maine, mit
beriicksichtigung einiger stticke von der Chaleur-Bai, Canada. Palgontographica,
Stuttgart, 86, B : 1-78, pls. 1-15.

Lane, W. H. 1931. On the Spines, Sporangia and Spores of Psilophyton princeps Dawson,

shown in specimens from Gaspé. Phil. Tvans., London, 219, B : 421-442, pls. 27, 28.

1932. Contributions to the Study of the Old Red Sandstone Flora of Scotland, VIII.

On Arthrostigma, Psilophyton and some associated Plant-remains from the Strathmore Beds

of the Caledonian Lower Old Red Sandstone. Tvans. Roy. Soc. Edinb., 57: 491-521,

pls. 1-4.

MAHABALE, T.S. 1956. Trends of specialisation in the sporocarp and spores in the living and
fossil Marsileaceae. Palaeobotanist, Lucknow, 5: 66-72, pls. I, 2.

McGrecor, D.C. 1960. Devonian spores from Melville Island, Canadian Arctic Archipelago.
Palaeontology London, 3: 26-44, pls. 11-13.

Naumova, S. N. 1953. Complexes sporo-polliniques du Dévonian Supérieur de la Platforme
russe et leur signification stratgraphique. Tvav. Inst. Sci. geol. Akad. Nauk. S.S.S.R.,
Moscow, 143 (Geol., 60) : 1-204. [In Russian].

Pant, D. D. & SHRivastava,G. K. 1961. Structural studies on Lower Gondwana megaspores,
Part 1. Specimens from the Talchir Coalfield, India. Palaeontographica, Stuttgart,
109, B: 45-61, pls. 30, 31.

PLAYFORD, G. 1962. Lower Carboniferous microfloras of Spitsbergen, I. Palaeontology,
London, 5: 550-618, pls. 78-87.

Potoni£, R. 1956. Synopsis der Gattungen der Sporae dispersae, I. Sporites. Beth. Geol.
Jb., Hannover, 23 : 1-103, pls. 1-11.

PoToni£, R. & Kremp, G. 1954. Die Gattungen der palaozoischen Sporae dispersae und ihre
Stratigraphie. Geol. Jb., Hannover, 69 : 111-194, pls. 4-20.

RIcHARDSON, J. Middle Old Red Sandstone spore assemblages from the Orcadian Basin,
North East Scotland. Palaeontology, London. (In Press).

ScHorr, J. Witson, L. R. & BenTALt, R. 1944. An annotated synopsis of Paleozoic fossil
spores and the definition of generic groups. Rep. Invest. Ill. Geol. Surv., 91 : 7-66, pls. 1-3.

Waite, D. 1905. Jn SmitH, G. O. & WuHiTE, D. The Geology of the Perry Basin in South
Eastern Maine. Pyvof. Pap. U.S. Geol. Surv., Washington, 35 : 9-92, pls. 2-6.

: ; _

PLATE 1

Archaeopteris cf. jacksoni (Dawson)
Upper Devonian ; Scaumenac Bay, Quebec

Fic. 1. Part of a fertile primary pinna bearing 18 or 19 pinnae, x}. V.4471I.

Fics. 2, 3. Fertile pinnae from which spore-masses were dissected out. The ring (Fig. 3)
surrounds two microsporangia and one megasporangium on the same pinnule. Fig. 2 X1.
Fig. 3, X2. V.51316, V.51312.

Fic. 4. Small megaspore-mass with a cutinised basal projection, x50. V.51326.

Fic. 5. Microspore-mass, x50. V.51327.

Fic. 6. Megaspore-mass, X50. V.51327.

Fic. 9. Microspore separated from microspore-mass, X 500. V.51316.

Barinophyton richardson (Dawson)
Upper Devonian ; Perry, Maine
Fics. 7, 8. Specimens from which spores were isolated (part and counterpart), XI.
V.51350, V.51351.
Fic. 10. Microspore, x 500. V.51357.
Figs. 1-3, 7, 8 were photographed under xylol.

PLATE

Bull B.M. (N.H.) Geol. 10, 3

PLATE 2

Fic. 1. Avchaeopteris cf. jacksont (Dawson). Megaspore, X 200. V.51325.
Fic. 2. Bavrinophyton richavdsoni (Dawson). Megaspore, X200. V.51357.

Archaeopteris latifolia Arnold
Upper Devonian ; Pennsylvania.

Fics. 3, 6. Megaspores recovered from maceration residues of matrix, xX 200. V.5131I,
V.51310.

Fics. 4, 5. Incomplete sporangium cuticles showing a clear cellular reticulum. A thinner
longitudinal zone is seen towards the right in Fig. 5. The circular objects are microspores.
The background has been painted out. 50. V.51302, V.51303.

Fic. 7. Microspore inside sporangium cuticle, x 500. V.51303.

Fic. 8. Sporangium cuticle with adherent tapetal globules, x 450. V.51303.

PLATE 2

Bull. B.M. (N.H.) Geol. 10, 3

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Sah ids aaa

SILURIAN POLYZOA FROM
BENTHALL EDGE, SHROPSHIRE

ee A 7
San.
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_D. E. OWEN

“

Ber BULLETIN OF
BRITISH MUSEUM (NATURAL HISTORY)
LOGY stg : Vol. 10 No. 4
et LONDON: 1965

mewrRIAIN POLYZOA FROM BENTHALL EDGE,
SHROPSHIRE

DEP OW EN, PhD:

(The Manchester Museum)

Pp. 93-117 ; Plates 1-6

BULLETIN OF
THE BRITISH MUSEUM (NATURAL HISTORY)
GEOLOGY Vol. 10 No. 4
LONDON : 1965

THE BULLETIN OF THE BRITISH MUSEUM
(NATURAL HISTORY), tmnstituted im 1949, 1s
ussued 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.

This paper is Vol. 10, No. 4 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)

Issued April 1965 Price Twenty-seven Shillings

SeORIAN POLYZOA FROM BENTHALL EDGE,

SHROPSHIRE
By DAVID ELYSTAN OWEN

CONTENTS
Page
I. INTRODUCTION ‘ ; : j . ‘ ; : . 96
II. AGE OF THE MATERIAL : . . 5 : : : ¢ 97
III. MerTHOD OF SECTIONING . : ‘ ‘ ‘ ; : : 98
IV. SySTEMATIC DESCRIPTIONS : ; P F : , F 98
Order Cyclostomata Busk : : : : : ‘ : 98
Family Diastoporidae Gregory . : ‘ : : : 98
Genus Mitoclema Ulrich . : ; 5 F 5 A 98
M. vegularis (Vine) : : : : ; : 99
Family Ceramoporidae Ulrich. p : . ; 5 99
Genus Ceramopora Hall ; ; d ‘ : 5 99
Ceramopora sp. . 4 : ; : 100
Genus Favositella Etheridge & Foard : : : é 100
F. inteypuncta (Quenstedt) ; : : : : 100
Family Fistuliporidae Ulrich : : ; ¢ : : 101
Genus Fistulipora McCoy : : : : : ; 101
F. crassa (Lonsdale) ; : : : : ; 101
Order Trepostomata Ulrich . : : : : : é 102
Family Batostomellidae Miller. 5 ‘ : : : 102
Genus Eridotrypa Ulrich . : : : 3 : : 102
E. cylindrica sp.nov. . é : : 3 ‘ 103
E. cavasp.nov. . 0 c 0 : 5 : 104
Evidotrypasp .. : é : : 104
Family Stenoporidae Waagen & Wentzel F : : : 105
Genus Leioclema Ulrich . : : ; ‘ : ‘ 105
L. denstpovum sp. nov. .« : 5 : : F 105
L. asperum (Hall) . L : ‘ 3 A : 106
L. vamosum sp. nov. 2 : : . ° : 107
Family Constellariidae Ulrich : é 3 ; : : 107
Genus Nicholsonella Ulrich : : : : ; ; 107
N. parva sp. nov. : : : é 4 : 108
Family Halloporidae Bassler : c : : é : 109
Genus Hallopora Bassler . : : : : ; : 109
H. elegantula (Hall) : ; : : ; : 109
H. striata (Hall). : c : 0 5 6 110
Family Amplexoporidae Miller. : ‘ : : 5 II
Genus Monotrypella Ulrich : 3 é : : c IIl
M. benthallensis sp. nov. : : : ‘ é 111
Genus Monotrypa Nicholson’ . é : 6 : 9 112
M. flabellata Owen : . ¢ 5 5 : 112
Order Cryptostomata Vine. : é : j : : 113
Family Rhabdomesidae Vine : : : ; : : 113
Genus Rhombopora Meek ‘ ‘ : 5 : é 113
R. mawi sp. nov. . ; 3 : : 5 . 113
Family Rhinidictyidae Ulrich. : : 5 5 : 114
Genus Pachydictya Ulrich ‘ : : : : 5 114
P crassa (Fall). : : : 5 : : T15
V. ACKNOWLEDGEMENTS : c 6 . . : ‘ : 116

VI. REFERENCES . : : ; : ; : , ; : 116

96 SILURIAN POLYZOA FROM BENTHALL EDGE, SHROPSHIRE

SYNOPSIS

A small collection of Polyzoa from Wenlockian strata of Benthall Edge, Shropshire, contains
seventeen species, four of which were described from American Silurian rocks and seven of which
are new.

I. INTRODUCTION

WuEN Davidson was writing his great series of monographs on British Fossil
Brachiopoda for the Palaeontographical Society he had some assistance from George
Maw of Benthall Hall, south-west of Ironbridge. Maw was a keen amature
geologist and was wonderfully placed for collecting from the Wenlock series. The
methods he employed to acquire a really representative fauna were a cross between
modern wholesale collecting and factory labour of the Industrial Revolution and
were charmingly described (Maw im Davidson & Maw 1881 : 100-101) with colourful
details. Some twenty tons of shale from Wenlock and Ludlow beds from approxi-
mately forty localities were collected, crushed, washed and sieved, and women were
employed at one shilling and sixpence a day to pick out the fossils. Further, the
old quarries on Benthall Edge were picked over by hand. The brachiopods were
all handed over to Davidson, who described the additions to his earlier species in a
special supplement (1881).

The Polyzoa came into the hands of G. R. Vine of Sheffield. Vine had been
interested in Polyzoa at least as early as 1877 when he started a series of papers on
Carboniferous forms from Yorkshire, many of which were published in the Pro-
ceedings of the Yorkshire Geological and Polytechnic Society. Vine wrote to Maw
and asked permission to examine the Polyzoa from the washings, and was sent
approximately two and a half hundredweight of small fragments which he proceeded
to work through with a hand lens. He described how he picked out upwards of two
hundred thousand specimens of small corals, Polyzoa, Entomostraca, etc., and
embarked on the description of the Polyzoa, publishing his first paper in the Quarterly
Journal of the Geological Society in 1882. He described a number of species, a few
of them new, and was very strong on the Ctenostomata and on certain of the simple
Cyclostomata. It is clear, however, that he was very uncertain of the great mass
of Trepostomata, of Ceramoporoid Cyclostomata and of Cryptostomata other than
the reticulate forms. Such names as Drymatopora problematica Vine, Polypora
problematica Vine and Thamniscus problematica Vine hint of his difficulties, and his
last paragraph (1882 : 68) reads “‘ I have endeavoured, in the above paper, to give
as few microscopical details as possible, because these seemed to me to be rather out
of place. I cannot, however, let the paper pass beyond my control without saying
that every species recorded has been examined macroscopically and microscopically.
The sections prepared have revealed many unexpected features that will help to
throw some light at least upon the development of the Polyzoa generally, and upon
the biological history of the Silurian Polyzoa in particular’’. In his list of species,
Monticulipora sp., which he thought, with Nicholson (1879 : 253), was a coral, was
noted (p. 47) as “very rich, but the whole wants working’’. Later (1886a : 228)
he wrote “‘ had I met someone who would have cooperated with me, the Actinozoa
division, chiefly the Monticuliporidae of my list, would have been much fuller than
ELS

SILURIAN POLYZOA FROM BENTHALL EDGE, SHROPSHIRE 97

The following year (1883) Vine read a second paper to the Geological Society of
London, but this appears only in abstract. Thirty-nine genera of corals and Polyzoa
were listed and two new species, Leioclema granatus Vine and L. pulchellus Vine,
were described. Unfortunately the manuscript is not in the library of the Geological
Society. After that, Vine returned to his native Yorkshire and his final two Silurian
Polyzoa papers (1886 and 1886a) were in the Proceedings of the Yorkshire Geological
and Polytechnic Society. In these again he described and listed species, but his
emphasis was largely on Ctenostomata which he knew and understood well. He
also wrote at length on the classification of the group both here and for the British
Association as secretary of a Committee making a study of them (1881).

Thus, at a time when Ulrich was publishing papers on Ordovician, Silurian,
Devonian and Carboniferous Polyzoa, superbly illustrated with lithographs showing
the species in section, and Nicholson sectioning Monticuliporids, the opportunity of
describing completely the Silurian polyzoan fauna from such a wealth of material
was lost. Thirty years after his death, Vine’s son handed over his geological col-
lections to Sheffield Museum. All that is left there of the two hundred thousand
specimens picked out are about two hundred mounts each containing one or more
specimens, nearly half of which are corals. Amongst them are a very few sections
too poor and thick to be of much use. In addition, there is a tray containing small
boxes of unsorted material from the numbered localities and a further tray containing
other unsorted material. Besides the Sheffield collection, there are a number of
mounts with similar specimens and thick microscope sections in the collections of the
British Museum (Nat. Hist.), the Geological Survey Museum and the Welsh National
Museum at Cardiff. Throughout, many of the mounts often contain more than one
species. In addition, there are three trays in the British Museum (Nat. Hist.) which,
through the courtesy of Dr. H. Dighton Thomas, I have been able to examine. Two
are not particularly rich, and their labels suggest that they contain mixed portions
from several localities. The third, labelled Benthall Edge, contains a quantity of
first-class material. It is from this tray that all the specimens described in this
paper have been separated.

It was not until I had spent a considerable time isolating, sectioning and mounting
these specimens that I found the Sheffield material (at the suggestion of Professor
L. R. Moore). Having examined it carefully, I do not think any useful purpose
would be served by including it in this review.

Throughout this paper I have followed the custom of the British Museum (Nat.
Hist.) and referred to this group as Polyzoa. In common with many workers over-
seas I have previously used the name Bryozoa. I have, however, recently re-read
Thompson (1830) and am quite satisfied that the name Polyzoa properly refers to
these creatures and should be accepted on grounds of priority.

Il. AGE OF THE MATERIAL

The material consists of some thousands of fragments mostly around a few milli-
metres in length and 0°5 to 3 mm. in diameter. It appears to be a portion from one
sifting and the label ‘“‘ Benthall Edge” suggests that it is the washings from that

98 SILURIAN POLYZOA FROM BENTHALL EDGE, SHROPSHIRE

locality, north-east of Much Wenlock. There the massive Wenlock Limestone
rests on the very fossiliferous Tickwood Beds, and it seems most likely that the
washings were from those shales. The old quarries and exposures are heavily
overgrown to-day, but similar material occurs at this level.

The Tickwood Beds are described (Whittard 1952 : 169) as being the uppermost
members of the thick Wenlock Shale and to lie in the zone of Cyrtograptus lundgreni,
and there is little doubt that this zone also includes at least the lowermost beds of
the Wenlock Limestone. The probability, then, is that the Polyzoa described here
are from beds of this age.

The species belong to the three orders Cyclostomata, Trepostomata and Crypto-
stomata, and the two typical Silurian genera Lezoclema and Evidotrypa are both well
represented. The deposit from which the material appears to have been collected
is very similar in lithology to a number of levels in the Ludlovian, yet the polyzoan
fauna is almost entirely different. The only three species common to both are
Fistulipora crassa (Lonsdale), Favositella interpuncta (Quenstedt) and Monotrypa
flabellata Owen. This suggests that the smaller Polyzoa may be of some use for
zonal purposes over a limited area.

On the other hand, only four species—Hallopora elegantula (Hall), Hallopora
striata (Hall), Letoclema asperum (Hall) and Pachydictya crassa (Hall)—appear to be
common to this deposit and the highly fossiliferous Rochester Shales of New York
State whose Polyzoa were described by Bassler (1906). I have looked in vain for
more of the characteristic species from that deposit. In the same way I have looked
for these British species in the Russian literature, particularly of Astrova (1959) and
Nekhoroshev (1961), but have not found them.

Ill. METHOD OF SECTIONING

A very large number of the specimens for study were small, measuring only a few
millimetres in length and perhaps one or two millimetres in diameter. In order to
be sure of getting the proper sections correctly orientated, I cut such specimens into
three parts using a small diamond cutting wheel mounted on a dental drilling
apparatus. One portion was then mounted for reference, and the other two em-
bedded in a proprietary brand of hard plaster of paris. It was then possible to
grind away sufficient of each specimen to show the tangential and the vertical
sections, to mount them on glass, and to complete the microscope slide. Besides
allowing the right planes to be ground on the material, the plaster was of great value
in holding together friable specimens which otherwise tended to break up before the
section was sufficiently thin to show such features as the laminae in the walls.

IV. SYSTEMATIC DESCRIPTIONS
Order CYCLOSTOMATA Busk 1852
Family DIASTOPORIDAE Gregory 1899
Genus MITOCLEMA Ulrich 1882

Ulrich described this genus to include simple Polyzoa with slender ramose zoaria
with more or less prominent apertures arranged in transverse series around the

SILURIAN POLYZOA FROM BENTHALL EDGE, SHROPSHIRE 99

branches or in an irregular spiral. He compared it with both Spzvopora Lamouroux
and Entalophora Lamouroux, but pointed out that those forms were Jurassic to
Recent and that there were no known links with the Palaeozoic species, then des-
cribed only from the Ordovician. He therefore felt that these last should be placed
in a separate genus. Silurian forms are now known to be fairly common and links
may yet be found in the younger Palaeozoic and the older Mesozoic beds. The
family is an interesting one in the simplicity of its form and structure and the fact
that it continues with little change from Ordovician to Recent times.

Mitoclema regularis (Vine) comb. nov.
Rin iwatios. 1.2:
1882 Spivopora vegularis Vine : 55, text-figs. 4-6.

MATERIAL. PD 4233-309.

DESCRIPTION. The zoaria consist of slender cylindrical tubes with raised circular
zooecial apertures on all sides forming an irregular spiral. Simple zooecia arise
centrally and run parallel to the axis, finally curving out slightly to reach the surface
at an angle of about 45 degrees. No diaphragms, mesopores, or acanthopores occur.

MEASUREMENTS.

Diameter of zoaria : : ; : : ‘ I mm.
Apertures raised up é 5 ; ‘ ; 5 Orang
Diameter of apertures. : =) 072mm:
Number of apertures in 2 mm. Woneraddinally ; : 15
Number of apertures in 2 mm. laterally : : 6

Remarks. This beautiful little species is moderately common in the collection
and is very characteristic. In worn specimens, as was noted by Vine, the outer
zooecial wall below the aperture is often perforated, showing a single long cavity
from the aperture or even an aperture and a hole beneath it. Vine placed the species
in the Mesozoic genus Sfivopora, which it closely resembles. Bassler (1952 : 381)
introduced Mitoclemella to take the species of Mitoclema with zooecial apertures
spiralling round the zoarium. Ulrich’s original description of Mztoclema allowed
for such species and I therefore retain this species in his genus.

Family CERAMOPORIDAE Ulrich 1882
Genus CERAMOPORA Hall 1851

Hall (1851 : 400) described this as incrusting or flattened hemispherical with
cells arranged in alternating or imbricating series, the apertures arching or triangular
with the apex above. Though he placed it among the corals, he noted that it was
probably a polyzoan. Ulrich (1890: 463, pl. 39, figs. 1-1) chose as type species
C. imbricata from the Rochester Shale at Lockport, New York, and he re-described
it and figured its internal structure as shown by sections. He stated that the lower
or basal portion of the zoarium was composed of a cellular or spongy tissue from
which the zooecia grew out more or less obliquely. He further pointed out that the

10o SILURIAN POLYZOA FROM BENTHALL EDGE, SHROPSHIRE

intercellular space between the non-tabular zooecia was occupied by irregular
flexuous rows of mesopores, the zooecia and tubes interconnecting by perforations
in the walls. Lunaria were said to be small but well-marked.

Ceramopora sp.
Plbaientie Seagyna:

MATERIAL. PD 4240-42.

DESCRIPTION. Zoaria small and discoid. Zooecia occur as simple inverted
cones and cylinders with thick granular walls. Mesopores are common, sometimes
closed, with numerous curved diaphragms forming in places vesicular tissue which
is much thicker at the base of the specimen. Apertures are large, nearly circular,
with small lunaria, in contact or separated by polygonal mesopores. Acanthopores
are wanting.

MEASUREMENTS.
Diameter of zoarium : F : : : : 5 mm.
Thickness of zoarium. ; é : 2mm.
Size of apertures . : 7 5 O- ae Oo: 5 X 0:4-0°55 mm.
Width of lunaria . ‘ ‘ ; : . 0*16—0-20 mm.
Size of mesopore apertures. : closed to 0-2 & 0:2 mm.
Number of apertures in 2 mm. : ; : 4
Thickness of walls : | (OF oyeo; 15 mm.

REMARKS. This species is meneniad on a sind specimen whose slightly
hollowed upper surface is typical of the genus. The thick mass of vesicular tissue
resolves itself into mesopores, most of which die out before reaching the surface.
Though similar in zoarial shape to the species of the Niagara Limestone and Roch-
ester Shales of New York State and to the Silurian forms from Gotland, it differs in
having greater regularity of zooecial form and less looseness. As this is a single
specimen whose preservation is not perfect, it is not here described as a new species.

Genus FAVOSITELLA Etheridge & Foord 1884
Favositella interpuncta (Quenstedt)

1878 Favosites inteypunctus Quenstedt : ro, pl. 143, fig. 9.

1884 Favositella interpuncta (Quenstedt) Etheridge & Foord : 473, pl. 16, figs. 1-1f.
1911 Favositella interpuncta (Quenstedt) ; Bassler : 100, fig. 35.

1962 Favositella interpuncta (Quenstedt) ; Owen : 197, pl. 28, figs. 1, 2.

MATERIAL. PD 4243-45.

RemARKS. A single, typical, small, encrusting specimen of this species occurs in
the collection. It shows the uneven perforated walls with dark granular centres,
the tabulated mesopores and even the enclosed “ brown bodies” or “ pearls ”’
described by Oakley (1934). It is a relatively poor specimen. With regard to the
description of both genus and species, I have nothing to add to my comments

(1962 : 197).

SILURIAN POLYZOA FROM BENTHALL EDGE, SHROPSHIRE IOI

Family FISTULIPORIDAE Ulrich 1882
Genus FISTULIPORA McCoy 1849, emend. Nicholson & Foord 1885

The genus was first described by McCoy (1849 : 130) in the following words :—
“ Corallum incrusting, composed of long, simple, cylindrical, thick-walled tubes,
the mouths of which open as simple equal circular cells on the surface, and having
transverse, funnel-shaped diaphragms at variable distances ; interval between the
tubes occupied by a cellular network of small vesicular plates’. Later, Nicholson
& Foord (1885 : 500) re-described it more fully, noting that it was variously shaped,
that the cylindrical zooecia had lunaria, that diaphragms were horizontal, that
tabulate mesopores often coalesce to give rise to vesicular tissue, and that occasional
acanthopores occur in the zooecial walls forming blunt spines at the surface. This
was the first time that the terms “‘ mesopore ”’ and “ acanthopore ”’ were used and
the lunules (lunaria) were also named. It should be remembered that Nicholson
still considered the genus to belong to the corals. Acanthopores are not now con-
sidered to occur in the genus.

This amended description seems to sum up the genus fairly accurately though the
number of species now described is so great that it may need further study.

Fistulipora crassa (Lonsdale)
eee ties Sete PIS 2 shes.) ieee)
1839 Heteropora cvassa Lonsdale : 680, pl. 15, figs. 14—14a.
1884 Fuistulipora crassa (Lonsdale) Nicholson : 118, pl. 7, figs. 1—2a.

1885 Fistulipora crassa (Lonsdale) ; Nicholson & Foord : 506, pl. 15, fig. 1.
1962 JF istulipora crassa (Lonsdale) ; Owen: 197.

MATERIAL. PD 4246-67.

DESCRIPTION. Zoarium ramose or encrusting, in the latter case often covering
other species of Polyzoa, and consequently difficult to distinguish macroscopically
from the ramose form. Ramose examples are occasionally slightly flattened.
Neither maculae nor monticules are seen and lunaria occur as complete rings, slightly
raised around the apertures. Zooecia are simple, thin-walled tubes, in ramose forms
running parallel and then curving gently outwards to reach the surface at right
angles, and in encrusting forms arising from a basal epitheca at a low angle and
curving gently to the surface, with occasional diaphragms. Mesopores occur as a
vesicular mass, but in ramose forms are to be found in the exozone only. Apertures
are circular to oval, completely ringed by lunarial tissue ; mesopore apertures are
polygonal, often closed at the surface by calcareous tissue.

MEASUREMENTS.
Diameter of ramose zoaria_.. : ; i . 2-4 mm.
Thickness of encrusting zoaria : : : 0°5-1:25 mm.
Size of apertures . : . Or15-0O'2 mm. X O-I-O0-15 mm.
Thickness of lunarial tissue. : , . 0*02-0:04 mm.
Size of mesopore apertures . 0:08-0:12 mm. X O-I-0-16 mm.

Number of apertures in 2 mm. ‘ : i ; 6-9

102 SILURIAN POLYZOA FROM BENTHALL EDGE, SHROPSHIRE

REMARKS. The ramose forms are common in the collection and the encrusting
forms rather less so. The similarity in the exozone of the ramose forms and the
entire encrusting forms is such that I have no hesitation in placing them in the same
species. They are indistinguishable in tangential section and a complete incrustation
of another ramose polyzoan makes it impossible to distinguish them without a
vertical or transverse section. Furthermore, both forms are notable for the lunaria
completely encircling the apertures, a fact noted by Nicholson (1884 : 118) when he
re-described the species. Both have a thin cortex of calcareous tissue which often
hides the mesopore apertures. Both Lonsdale and Nicholson had specimens from
Benthall Edge, Lonsdale’s figured specimen (1839, pl. 15, fig. 14) being Io mm. in
diameter and Nicholson’s specimens being described as 2-12 mm. across. Nicholson
& Foord (1885, pl. 15, fig. 1) figure a very large specimen. The ramose specimens
described here vary from 2—4 mm. and, like those in Nicholson’s description (1884 :
118), are slightly flattened.

Nicholson (1884 : 119) described Fistulipora ludensis as a small encrusting form
otherwise very similar to F. crassa. It was said to differ in having spiniform tubules
(acanthopores) and rather more mesopores, as well as in its zoarial form. I have not
seen any specimens of this species and neither have I seen acanthopores in the genus.
It seems possible that Nicholson mistook certain thickenings in the lunaria for
acanthopores and that this species is the encrusting form of Ff. cvassa (Lonsdale).
Fistulipora dobunica (Nicholson & Foord 1885: 511, pl. 17, figs. 3-36) was also
described as an encrusting form from the Wenlock Limestone, but its well-marked
maculae and its very tiny apertures (12 in 2 mm.) distinguish it. Fistulipora
lockportensis Bassler is the only one of four species of F'zstulipora described by Bassler
(1906 : 23, pl. 7, figs. 1-3) from the Rochester Shale which is comparable. While
the other three species have horseshoe-shaped lunaria, in that species they appear
as a complete ring. F. lockportensis is, however, a large and massive form, the
zoaria measuring as much as 10 cm. across and the apertures 4 to 2 mm.

Order TREPOSTOMATA Ulrich 1882
Family BATOSTOMELLIDAE Miller 1889
Genus ERIDOTRYPA Ulrich 1895

Ulrich introduced this genus to include certain species formerly described as
Batostomella, which he proposed to restrict to the Carboniferous, and for a number
of new species for which he could find no existing genus. He described it (1895 : 264)
as ramose with slender branches. ‘‘ Zooecia more or less oblique, with thick walls,
the tubes intersected by diaphragms only. The latter may be wanting in the axial
region, are in most cases absent for a short distance within the apertural edge, but
are always present and closest together in the turn from the axial into the narrow
peripheral region. Mesopores with close-set diaphragms, varying in number, some-
times abundant, at other times very few. Acanthopores small, never numerous,
sometimes wanting ’’. The most noticeable features of species in this genus to me
are the short, thickened walls of the exozone and the mesopores, often closed in this

SILURIAN POLYZOA FROM BENTHALL EDGE, SHROPSHIRE 103

region. In many species the base is expanded or encrusting and the ramose portion
rises from this. Where visible, the laminae show Leioclemid wall structure and
possibly link Evidotrypa to Leioclema, which differs mainly in the great development
of large acanthopores.

Eridotrypa cylindrica sp. nov.
BZ ties. 3.04.

Diacnosis. Evidotrypa with thin-walled zooecia without diaphragms in the endo-
zone and with thick mass of laminated tissue forming exozone and showing Leio-
clemid wall structure.

MATERIAL. Holotype PD 4268-70 (specimen and sections).
Paratypes PD 4271-78.

DESCRIPTION. Zoarium cylindrical, ramose. Zooecia occur as long, thin-walled
tubes in the endozone, bending sharply into the exozone where the walls thicken
and straighten out to reach the surface at about 70°. Wall laminae curve distally
in a marked figure U. Mesopores often closed, occur in exozone only. Diaphragms
in mesopores and occasionally in zooecia in exozone. The laminae of the diaphragms
show Leioclemid wall structure perfectly (cf. Boardman 1960 : 30, 31). Apertures
rounded to oval or polygonal with rounded corners, ringed around with dark tissue.
Mesopore apertures polygonal. Occasional small acanthopores, often difficult to
tell in tangential section from a nearly closed mesopore.

MEASUREMENTS.

Diameter of zoaria : : 5 ; : . 2-3mm.
Thickness of exozone. : : ; : o-8-1I-0 mm.
Size of apertures . . O'I14-0:2mm. X O-I-0-17 mm.
Thickness of spending ring : . 0°02—0:05 mm.
Size of mesopore apertures very saline to 0:06 x 0-04 mm.
Diameter of acanthopores ‘ : : ; . 0°02 mm.
Number of apertures in 2 mm. : ; 3 ; 8

Remarks. This is fairly easily recognisable macroscopically in an unworn speci-
men for the apertures appear polygonal and the mesopores and small acanthopores
are not visible. With the thick mass of laminated tissue in the exozone and Leio-
clemid wall structure, it differs from all other species in the collection, in which it is
relatively common. The thick tissue in the exozone, the sturdy rings round the
apertures, the closed mesopores and the presence of only very small acanthopores
lead me to place this species in Evidotrypa though its wall structure would seem to
ally it to Leioclema. In appearance it compares fairly closely with E. similis
Bassler (1g06 : 31, pl. 12, figs. 10-14; pl. 26, figs. 1, 2) but differs in being smaller
with smaller apertures, no thin diaphragms and smaller acanthopores.

104 SILURIAN POLYZOA FROM BENTHALL EDGE, SHROPSHIRE

Eridotrypa cava sp. nov.
Phe 2yfigss 5-6:

DraGnosis. Evidotrypa with massive walls and apertures sunk in hollows. In
the endozone the zooecia are closely tabulate, in the exozone they are ringed with
dark tissue which shows up in tangential section.

MATERIAL. Holotype PD 4285.

Paratypes PD 4279-84 and PD 4286-88.

DESCRIPTION. Zoarium ramose. Zooecia arise centrally, run parallel and then
turn sharply into exozone to reach the surface at or near a right angle. Walls in
endozone thick and diaphragms numerous at about half tube-width intervals. In
exozone, walls greatly thickened, integrate, with laminae which arise parallel to the
inner edge of the wall and curve distally in a broad U-shape, though the centre is
marked by an uneven black line. Only a few diaphragms enter the exozone. Small
mesopores arise in the exozone and acanthopores are also visible in this region.
Apertures oval and often partly closed by the thickness of the walls. The dark
rings around them, in which lie the acanthopores, give them the appearance of lying
in hollows, and in the solid specimen they are seen to do this. Mesopore apertures
are often partially or even completely closed.

MEASUREMENTS.
Diameter of zoaria : : ; : 2 I°5-2°5 mm.
Thickness of exozone : : ; . 0:4-0:8 mm.
Size of apertures. : 5 O-I-0°3 mm. X 0:05-0:2 mm.
Size of mesopore apertures . from closed to 0-08 x 0-06 mm.
Diameter of acanthopores : ; : . 0:02-0:04 mm.
Number of apertures in 2 mm. : : : ; 6
Thickness of wall between two apertures . j 0-06—0-2 mm.

REMARKS. This is a common species and is easy to recognise in the unworn
specimen through the massive walls and the apertures resting in hollows. Micro-
scopically it is equally characteristic both in tangential and vertical sections, and
differs in tabulation in the endozone and in massiveness in the exozone both from
other species of Evidotrypa and from other forms in the deposit.

Eridotrypa sp.
Rigs ties: 2)

MATERIAL. PD 4289-95.

DESCRIPTION. Zoarium encrusting, thin, but occasionally thickening. Zooecia
arise from a basal epitheca. In thin portions the endozone is very short and the
fairly thick walls thicken rapidly into the exozone, which consists of a mass of thick
calcareous tissue with threadlike hollow acanthopores running through. In the
expanded portion the thin zooecial walls arise at a relatively low angle from the basal
epitheca but quickly turn up towards the surface. They remain thin until they
expand into the calcareous exozone. Diaphragms few. No mesopores. The
polygonal apertures are surrounded by thick walls containing numerous small
acanthopores.

SILURIAN POLYZOA FROM BENTHALL EDGE, SHROPSHIRE 105

MEASUREMENTS.
Thickness of zoaria in thin encrustations . ‘ 0-2—0°3 mm.
Thickness of zoaria in expansion. 4 : : 2 mm.
Breadth of expanded portion . ; : : 7 2-5 gm.
Thickness of exozone . : ‘ ; : O-I-0:4 mm.
Size of aperture . ‘ . O14-0'18 mm. X 0O-I—-0-16 mm.
Number of apertures in 2 mm. ; : : . 10-12

REMARKS. This species is represented in the deposit by three specimens, two
encrusting fragments of crinoid stem and the third encrusting a small coral. In
PD 4293 there is a considerable expansion on one side, and the species is similar to
Enidotrypa umbonensis Owen, differing from it in its lack of mesopores and less even
shape of the apertures. The material is not sufficiently complete and well preserved
to allow a new species to be based on it.

Family STENOPORIDAE Waagen & Wentzel 1886
Genus LEIOCLEMA Ulrich 1882

Ulrich described this genus to include forms with encrusting, lamellar, subglobose
or ramose zoaria, with zooecia whose apertures often become petaloid by the en-
croachment of large acanthopores in the walls, and with abundant mesopores which
may even take on the vesicular appearance typical of Fistuliporids. Boardman
(1960 : 30) described a typical Leioclemid wall structure of diaphragm-wall units
which can often be traced across two or three adjacent mesopores. In Silurian forms,
I have not always found this wall structure though it shows clearly in some. This
may be due in part to imperfect preservation. The other features described by
Ulrich seem to me to distinguish it from associated genera.

Leioclema densiporum sp. nov.
Pls; fies..32A:.

Di1aGnosis. Ramose Lezoclema with polygonal mesopores and many acanthopores
surrounding and indenting each aperture.

MATERIAL. Holotype PD 4302-04 (specimen and sections).
Paratypes PD 4299-301 and PD 4305-08.

DEscRIPTION. Zoarium ramose, usually slender. Zooecia thick-walled through-
out, arise centrally and curve gently to reach the surface at or near a right angle.
Numerous mesopores and acanthopores develop in the exozone. Diaphragms few.
Wall structure fairly clear, showing few laminae, with the typical Leioclemid wall
not visible. Apertures oval, indented by the many moderate sized acanthopores,
and separated by polygonal mesopores.

106 SILURIAN POLYZOA FROM BENTHALL EDGE, SHROPSHIRE

MEASUREMENTS.

Diameter of zoaria : : ; : : I°5—2:5 mm.
Thickness of exozone. ‘ é 0:3-0-6 mm.
Size of apertures . yO 14-0: 18 mm. X 0:10-0:12 mm.
Size of mesopore aperhines . 0:08-0:16 mm. X 0:02-0:06 mm.
Diameter of acanthopores : ; : . 0:0I-0-:03 mm.
Number of zooecia in 2 mm. : : : 8
Thickness of zooecial wall at sumPace : ‘ _ (0:02) mir
Number of acanthopores around aperture j 8-12

REMARKS. The five specimens in the collection all show the same features quite
clearly. In the unworn figured holotype the indented apertures, spines marking
acanthopores, and polygonal mesopores are all clearly visible. I hesitate to leave
this species in Lezoclema as it does not show the typical Leioclemid wall and diaphragm
structure, though this is not unusual in other Silurian species. It is, however, very
typical of the genus as described originally by Ulrich (1882). It is not unlike the
description of L. multiporum Bassler though that species is encrusting. Bassler
(1906: 34) notes, however, that all of a small lot collected in Rochester, N. Y., differed
from the usual method of growth and formed dwarfed branches. It differs, however,
mainly in having larger zooecia and fewer mesopores.

Leioclema asperum (Hall)
Pl.3; figs. 530:

1852 Callopora aspera Hall: 147, pl. 4o.
1890 Leioclema asperum (Hall) Ulrich : 425.
1906 Lioclema (sic) asperum (Hall) ; Bassler : 32, pl. 11, figs. 1-3 ; pl. 24, figs. 14-16.

MATERIAL. PD 4300-11.

DESCRIPTION. Zoarium small, encrusting or massive. Zooecia simple tubes
arising from an epitheca and running directly to the surface with relatively few
diaphragms. Numerous tabulate mesopores with diaphragms approximately tube-
width apart. Large hollow acanthopores extend the whole depth. Once more it is
difficult to comment on the wall structure which is more granular than laminar.
Apertures circular or oval, deeply indented by the few very large acanthopores.
Mesopores oval or polygonal with well rounded corners.

MEASUREMENTS.
Diameter of figured specimen ; : : 25 me
Depth . ‘ : : : : o)) 25 om:
Size of apertures . : ; © ae —0'2 mm. X 0-12—0'15 mm.
Size of mesopore apertures .0:07-0‘I mm, X 0:04 X 0:07 mm.
Diameter of acanthopores : i ; : 0-05-0'I mm.
Number of apertures in 2 mm. : ; ; 8-9
Number of acanthopores to each ante ‘ : 2-4

Thickness of zooecial wall at surface F . . 0:02 mm.

SILURIAN POLYZOA FROM BENTHALL EDGE, SHROPSHIRE 107

REMARKS. This single specimen fits in very closely with Bassler’s description
(1906) and with specimens identified by him in the British Museum (Nat. Hist.)
collections. It is distinguished from other forms of Lezoclema in the deposit by its
encrusting habit and its particularly large acanthopores which show up clearly in
vertical as well as tangential sections.

Leioclema ramosum sp. nov.
Bi 3; figs’7, &

DraGnosis. Ramose Leioclema with thick walls in endozone and Leioclemid
wall structure clearly marked in exozone. Acanthopores one to three per zooecial
aperture.

MATERIAL. Holotype PD 4315-17 (specimen and sections).

Paratype PD 4312-14.

DESCRIPTION. Zoarium ramose. Zooecia arise centrally and curve gently out to
reach the surface at or even beyond a right angle. Walls fairly thick throughout,
but thickening markedly in exozone in which both mesopores and acanthopores
occur. The wall is typically Leioclemid (Boardman 1960 : 30-31), wall-diaphragm
units extending across many mesopores, the diaphragms occuring approximately a
tube-width apart. Diaphragms also occur in the exozone in the zooecia. Meso-
pores fairly numerous, sometimes closed. Apertures oval or polygonal with rounded
corners, mesopore apertures similar but smaller. Acanthopores relatively few and
very large, often indenting the side of the zooecial aperture, one, two, or at most
three to an aperture.

MEASUREMENTS.
Diameter of zoaria ; : 3 3 : 2-2°5 mm.
Thickness of exozone . : : 0-75-I mm.
Size of apertures . ‘ 0-12-0° 16 mm. X 0:08-0:12 mm.
Size of mesopore apertures. . Closed to 0-I x 0-05 mm.
Diameter of acanthopores ; F ; . 0°05-0:09 mm.
Number of apertures in 2 mm. : , , 10
Thickness of walls : ; : Up to O-I mm.

Remarks. This is one of the few Sider species of Lezoclema which shows the
wall structure clearly. It is not very different from Lzoclema [sic] rvamulosum
Bassler (1906 : 35, pl. 11, figs. 11-13 ; pl. 25, figs. 9, 10) but differs in having
relatively thick walls in the endozone and in having diaphragms. It differs from
other species of Lezoclema in the collection in its beautifully formed Leioclemid wall
structure, but otherwise compares closely particularly in tangential sections.

Family CONSTELLARIIDAE Ulrich 1890
Genus NICHOLSONELLA Ulrich 1890

This genus was introduced by Ulrich (1890 : 374, 421) to include four or five
Ordovician species, one of which had already been described by him as a species of

108 SILURIAN POLYZOA FROM BENTHALL EDGE, SHROPSHIRE

Heterotrypa Nicholson. The type species, N. ponderosa Ulrich, is very large, andall
were described as having irregularly intertwining flattened branches or fronds.
Zooecia were said to be tubular with circular apertures and a faint granular peristome.
The walls were thin and traversed longitudinally by minute tubul. The numerous
angular mesopores were said to isolate the zooecia, but acanthopores were not
mentioned. With age the interzooecial spaces were said to become filled with a
perforated calcareous deposit. The figures showed the shadowy nature of the walls.
Bassler (1906 : 38, 39, pl. 14, figs. 10-14 ; pl. 24, figs. 1, 2) added two Silurian species
from the Rochester Shale of New York State. Both were explanate expansions and
were very similar to Ulrich’s Ordovician forms with the same shadowy walls and the
calcareous deposit filling interzooecial spaces, but both had many large granular
acanthopores. I have examined sections of Nicholsonella florida (Hall) in the
British Museum (Nat. Hist.) collections named by Bassler, and feel that the genus
would be more properly placed in the Cyclostomata near Fistulipora. In describing
F. umbrosa Owen (1960 : 69, 70, pl. 16, figs. 1, 2) I was struck by the similarity of the
shadowy walls to those of species of Nicholsonella, but felt that it was otherwise a
very typical Fistuliporid. Such walls occur frequently in Ceramoporoids and less
often if at allin the more typical Trepostomata.

Nicholsonella parva sp. nov.
PinAy igss 2:

DiaGnosis. Small Nicholsonella with numerous large acanthopores which only
slightly indent the apertures.

MATERIAL. Holotype. PD 4321.

Paratypes PD 4318-20.

DESCRIPTION. Zoaria hemispherical or encrusting, small, with spiny projections
marking the position of stout acanthopores. Zooecia short, straight or curved with
moderately thick granular walls and no diaphragms. Mesopores common, tabulated,
diaphragms approximately a tube-width apart. Acanthopores large with hollow
centres and granular walls about three to a zooecium. Apertures circular or oval,
touching or separated by polygonal mesopores, frequently slightly indented by
acanthopores.

MEASUREMENTS.
Breadth of hemispherical zoarium_ . : . . 4-5 mm.
Height of hemispherical zoarium : : 5 3 mm.
Size of apertures . : F ; 0-3-0:4 mm. diameter.
Size of mesopore apertures . 0:05-0:08 mm. X 0-06—-0-I mm.
Diameter of acanthopores : 5 ; . 0:05-0:08 mm.
Number of zooecia in 2mm. . . 4-5

REMARKS. The shadowy nature of the walls and the simple tubular zooecia
place this species clearly in Nicholsonella. Only three specimens occur in this
collection, two hemispheres and one thin incrustation. The zooecia are slightly
smaller than those of N. florida (Hall 1852 : 146, pl. 40, figs. 2a—f), the mesopores less

SILURIAN POLYZOA FROM BENTHALL EDGE, SHROPSHIRE 109

vesicular, the acanthopores fewer and relatively larger, and the apertures less flori-
form, but otherwise this species is very like Bassler’s description (1906 : 38, pl. 14,
figs. 10-11 ; pl. 24, figs. 1, 2) of Hall’s species, which has, however, large explanate
zoaria. It also differs from N. vinguebergi Bassler (1906 : 39, pl. 14, figs. 12, 13)
in having larger zooecia whose apertures are not so deeply indented as to be petaloid
as is the case in that species.

Family HALLOPORIDAE Bassler 1911

Genus HALLOPORA Bassler 1911

This was introduced as a new name for Callopora Hall (non Gray 1848 : 109, 146).
Hall described Callopora (1851 : 400) as “‘ ramose or incrusting with a columnar
structure ; cells tubular with the apertures circular or petaloid, not contiguous, and
having the intermediate spaces occupied by angular cell-like openings which are
transversely septate ; tubular cells rarely septate’. The type species, C. elegantula
Hall, was well figured in 1852 (pl. 40, fig. 1-17), and it shows clearly the characters
of the genus. Bassler added, in his renaming (1911 : 325), that zoaria of Hallopora
were almost always solid, ramose and bushy, and in the perfect state the apertures
were closed by perforated ornamental covers, which, as growth proceeded, formed
the diaphragms of succeeding layers.

Hallopora elegantula (Hall)
Bl eArniess 3,04:

1852 Callopova elegantula Hall: 144, pl. 40, figs. 1-17.

1882 Callopova elegantula Hall ; Ulrich : 250, pl. 11, figs. 6—6b.

1884 Callopova nana Nicholson : 120, pl. 7, figs. 4—4b.

1906 Callopora elegantula Hall ; Bassler : 41, pl. 17, figs. 11-15 ; pl. 26, fig. 12.
1911 Hallopova elegantula (Hall) ; Bassler : 334, text-fig. 210.

MATERIAL. PD 4322-33.

DESCRIPTION. Zoaria ramose often relatively stout. Zooecia arise from centre
and curve gently out to reach the surface at right angles. Diaphragms numerous
and closely spaced in endozone, becoming fewer in exozone where numerous closely
tabulated mesopores occur. Zooecial wall integrate in the inner part of the exozone,
with laminae running a short distance nearly parallel to the wall and forming a V
distally, which shows up as a black line in section, but the V and the black line
become much less marked near the surface. Mesopore diaphragms show Leioclemid
wall structure, the laminae of one diaphragm running into the wall distally and
curving back from a blunt V to run into the diaphragm of the next mesopore. No
acanthopores. Apertures circular or oval, separated by polygonal mesopores.

MEASUREMENTS.
Diameter of zoaria : : : : 5 . 2-5 mm.
Size of apertures . : : 0:3-0'4 mm. X 0:25—-0°3 mm.
Size of mesopore apertures. O-I-0'2 mm. X 0:05-0-2 mm.

Number of apertures in 2 mm. f : : : : 5

110 SILURIAN POLYZOA FROM BENTHALL EDGE, SHROPSHIRE

REMARKS. This is the commonest polyzoan in the collection and one of the
commonest in the Wenlockian. It is easy to distinguish macroscopically by its
relatively stout form and the circular apertures clearly separated by mesopores.
Microscopically in all sections it is quite distinctive. It tallies exactly with Hall’s
description and figures and with specimens from the U.S.A. named by Bassler. It
also compares with Vine’s sections of Callopora nana Nicholson. In his original
description of C. nana, Nicholson mentioned C. elegantula Hall but did not compare
it with that species, even though he compared it with two American Ordovician
species. The description, figures and the specimen so named in the British Museum
(Nat. Hist.) collections are so like C. elegantula Hall that I have no doubt they are
conspecific and that C. nana Nicholson is a junior synonym of C. elegantula Hall.
Nicholson made the point in his species that both zooecia and mesopore apertures
are elongated along the long axis of the zoarium, and I note this to occur occasionally
but not generally. He described (1884 : 122, pl. 7, figs. 5-5) C. fletchert (Edwards
& Haime) (1885 : 267, pl. 62, figs 3, 3a) as having circular apertures, and figured
several mesopores adjoining one another, but he also noted the great thickening
of the wall in the exozone which distinguishes it completely from this species. [The
possible synonymy of C. fletcheri with Hallopora ramulosa (Phillips) has been dis-
cussed by Stubblefield (1938 : 30).]

Hallopora striata (Hall) comb. nov.
Pl. 4, figs. 5, 6.

1852 Tvematopora striata Hall: 153, pl. 40, figs. 7a—d.
1906 Evidotyvypa striata (Hall) Bassler : 32, pl. 12, figs. 4-6 ; pl. 24, figs. 3-6 ; pl. 25, fig. 14.

MATERIAL. PD 4296-08.

DESCRIPTION. Zoarium cylindrical, branching. Zooecia arise centrally and
curve gently to reach the surface at or near a right angle. Walls integrate, fairly
thick throughout, but thickening markedly in the exozone where the laminae are
relatively straight, V-ing distally to form a central dark line. Mesopores common,
sometimes closed. Diaphragms occur regularly throughout the length of the zooecia
at intervals of a half to one tube-width, though they are less frequent at the surface,
and in mesopores at approximately the same intervals. The laminae in the thick
diaphragms show that the diaphragms form a unit with the wall after the manner of
the Atachtotoechids (Boardman 1960 : 32), though the unit does not appear to
continue into the neighbouring zooecium in the same way. Apertures oval.
Acanthopores wanting.

MEASUREMENTS.
Diameter of zoaria : ; : : , . 2-2°3mm.
Size of apertures . : : 0:3-0°4 mm. X 0:2—-0:25 mm.
Size of mesopore apertures. ‘ . 006mm. X 0:04 mm.

Number of apertures in 2 mm. ‘ F : i - 4-5

SILURIAN POLYZOA FROM BENTHALL EDGE, SHROPSHIRE III

ReMARKS. This small species came to light in sectioning numerous specimens of
other species indistinguishable macroscopically. The integrate walls, tabulate
zooecia and lack of acanthopores are typical of Hallopora Bassler. I compared it
with sections in the British Museum (Nat. Hist) from Lockport, New York, labelled
by Bassler Evidotrypa striata (Hall), and found it to be identical. Bassler’s tan-
gential section shows dark dots which he clearly took to be acanthopores though I
am by no means certain that this is their real identity. The three specimens in the
collection do not permit of sufficient examination for re-description of the species,
but I consider that they, and Bassler’s specimens mentioned above, belong to
Hallopora Bassler and not Evidotrypa Ulrich.

Family AMPLEXOPORIDAE Miller 1889
Genus MONOTRYPELLA Ulrich 1882

Ulrich introduced this genus to include species very like those belonging to the
ramose genus Amplexopora Ulrich but differing in the absence of acanthopores and
in the presence in some species of what he described as closely tabulated interspaces
that simulated mesopores. In his figures these appear to be typical mesopores.

It is the presence of numerous acanthopores that is the greatest difference between
Amplexopora Ulrich and Monotrypa Nicholson, for both genera are always without
mesopores. There seems to be little difference between species of Monotrypella
without mesopores (or tabulated interspaces), and Monotrypa, though the latter was
founded on a large massive “ coral’ and the former on a small ramose “ polyzoan ”’.

Monotrypella benthallensis sp. nov.
PIS tes. iy.

Diacnosis. Monotrypella with polygonal zooecial apertures of two sizes and
Atactotoechid wall structure.

MATERIAL. Holotype PD 4334-36 (specimen and sections).

Paratype PD 4337.

DESCRIPTION. Zoaria ramose with groups of slightly larger zooecia but no true
monticules. Zooecia run parallel for some distance and then curve gently out,
finally making an angle or elbow to reach the surface at right angles. Zooecial
walls thin in endozone, with diaphragms few or wanting, but thickening in exozone
with a number of diaphragms mostly thin but a few rather thicker. Wall structure
integrate, Atactotoechid (Boardman 1960 : 32), with laminae making a small angle
with the walls and forming a V distally which shows as a dark line. Diaphragms
continue forward into the wall but are easily lost in its structure. Mesopores and
acanthopores wanting. Apertures polygonal, and integrate structure observable in
thin black line which separates them.

112 SILURIAN POLYZOA FROM BENTHALL EDGE, SHROPSHIRE

MEASUREMENTS.

Diameter of zoaria : ; : : : . 2-3 mm.
Thickness of exozone. ‘ : 0:2—0'°6 mm.
Size of larger apertures . : 0: oye —0° P mm. X 0-2—0:25 mm.
Size of smaller apertures : - 0:2-0:25 mm. X 0-15 mm.
Number of larger apertures in 2 mm. : : : : vi
Number of smaller apertures in 2mm. . ; ‘ 9
Maximum thickness of zooecial wall in exozone 0-06-0-Il mm.

REMARKS. The exozone may be very short and the wall structure is then less
easy to determine. The species is represented by four specimens and is easy to
recognize macroscopically by the polygonal shapes of the zooecia with their larger
groups, and by the lack of mesopores, and microscopically by the sharp angle which
the zooecia make in the exozone. The vertical sections are very similar to those of
Enidotrypa echinata Hall sp. (1879 : 112, pl. 11, figs. 1-5) named by Bassler in the
British Museum (Nat. Hist.) collections, but the tangential sections of that species
appear to show numerous very small acanthopores which are not present here.
Furthermore, I do not believe this species belongs to the genus Evidotrypa. Although
the wall structure appears to be Atactotoechid there are many differences between
this and species of that genus. Absence of cystiphragms and of intermittent thick-
ening of walls show that it is no near relative of Atactotoechus. The integrate wall
structure and absence of mesopores suggest the Amplexoporidae, and the lack of
acanthopores, the genus Monotrypella. 1 place it in this genus and not in Monotrypa
Nicholson as it is a small ramose polyzoan and differs in form from typical Silurian
species of Monotrypa.

Genus MONOTRYPA Nicholson 1879

This genus was first separated from Monticulipora by Nicholson (1879) and the
subject was further elaborated in 1881. The essential features were the absence of
mesopores, though the presence of larger and smaller zooecia, the former often
collected in monticules, was noted. Acanthopores were absent except in M. discoidea
(James) which was later removed from the genus. The walls were said to be thin,
seemingly structureless, and apparently amalgamated to one another in some species,
but in others were considerably thickened. In either case they were said to preserve
the original lines of demarcation separating each zooecium. Diaphragms were
entire, uniformly distributed, sometimes few or wanting.

This has since proved to be a very easily recognizable genus and many species
have been described. Crenulate walls have proved a feature in a number. Where
the walls are thick, their integrate nature and the black line formed by the V-ing of
the wall laminae are clearly observable in both tangential and vertical sections.

Monotrypa flabellata Owen
Pi Opies: a92)

1960 Monotrypa flabellata Owen: 72, pl. 16, figs. 10-11; text-fig. 6.
1962 Monotrypa flabellata Owen ; Owen: 109, pl. 32, figs. 1, 2.

SILURIAN POLYZOA FROM BENTHALL EDGE, SHROPSHIRE rea

MATERIAL. PD 4338-47.

DESCRIPTION. Zoarium small, encrusting or hemispherical, with groups of larger
zooecia showing on surface. Zooecia arise from the epitheca and are simple tubes
with crenulate walls and numerous simple diaphragms. The walls are markedly
integrate, with laminae arising from the inner sides at a low angle and running
distally to form a V which shows up as a black line through the length of the wall.
Apertures polygonal with the dark line of laminae clearly visible. No mesopores,
though occasional, smaller zooecia are seen in sections. No acanthopores.

MEASUREMENTS.
Breadth of zoaria : : : : : up to 7 mm.
Thickness of zoaria ; : : : up to 2 mm.
Size of aperture of larger zooecia_.. . O5 mm. X 0:33 mm.
Size of aperture of normal zooecia > Yo-3smim:, X< 0-2 mm.
Number of larger zooecia in 2 mm. . : : : . 5-6
Number of normal zooecia in 2 mm. : : ; ; 7
Thickness of zooecial walls. : : 0:2-0:3 mm.

Remarks. I place the specimens of Monotrypa in tine collections in this Ludlovian
species though there are certain slight differences. The occasional groups of larger
zooecia have not been observed in Ludlovian forms and the walls are, if anything,
even stouter. There are rather more diaphragms, though diaphragms are occasion-
ally numerous in Ludlovian specimens. The zoaria, too, are all smaller, though
zoaria of other species in the deposit are also small. The thick wrinkled walls with
the dark central line marked by the V-ing of wall laminae are so similar in these and
the typical Ludlow forms as to make me consider them conspecific.

Order CRYPTOSTOMATA Vine 1883
Family RHABDOMESIDAE Vine 1883
Genus RHOMBOPORA Meek 1872

The genus was introduced for the Carboniferous species, R. lepidodendroides Meek,
to include forms with slender, ramose, solid zoaria, and zooecia with vestibules within
a very thick outer wall, numerous acanthopores and no mesopores. Ulrich inseveral
papers (1890 ef alia) described many species in this easily recognizable genus. Some
had hemisepta serving to demarcate the vestibules. Moore (1929 : 134) discussed
the genus, and drew attention to the fact that the type species had no hemisepta, and
also that many forms described from older strata had hemisepta. Bassler (1953 :
G. 134) noted “no hemisepta’”’, but it seems that this is not a diagnostic generic
feature.

Rhombopora mawi sp. nov.
Pl. 5, figs. 3-5.

Diacnosis. Khombopora with hemisepta and mesopores, sometimes closed, with
thick diaphragms.

114 SILURIAN POLYZOA FROM BENTHALL EDGE, SHROPSHIRE

MATERIAL. Holotype PD 4350-52 (specimen and sections).
Paratypes PD 4348-49 and PD 4353-67.

DESCRIPTION. Zoaria ramose, some extremely slender and fragile and others
rather stouter and stronger. Zooecia thin-walled tubes in endozone curving slightly
from the axis and then turning more or less sharply to reach the surface at or neara
right angle. The exozone is very thick and solid in the stouter specimens but thinner
in the slim ones, and there are intermediate examples and even some with the exozone
thicker on one side than the other. Well-marked vestibules particularly in stouter
forms are completed with superior hemisepta and occasionally inferior hemisepta.
Wall laminae make a low angle with the wall and curve distally into a U-shape.
Occasional thin diaphragms occur. Mesopores are numerous in exozone, sometimes
closed, containing many thick diaphragms whose laminae run up into the wall laminae
after the manner of Leioclemids. Apertures are circular or oval, surrounded by a
well-marked ring. Large hollow acanthopores are very numerous, particularly in
the stouter forms, occurring in the thick calcareous tissue between the apertures,
sometimes breaking the ring but never cutting into the aperture. Macroscopically
the positions of the closed mesopores are marked by small depressions.

MEASUREMENTS.
Diameter of zoaria : 3 : 2 : 1-8—2°5 mm.
Thickness of exozone. : ; : : 0-2-0-7 mm.
Diameter of endozone . : : o-8-1:2 mm.
Size OlvapeLeurenmr : , O 08- O-I2 mm. X 0:05-0-Il mm.
Thickness of surrounding ring ; ; : = 0-02)
Number of apertures in 2 mm. : as g-II
Number of acanthopores surrounding amperes ; 5-10
Diameter of acanthopores ; : : . 0-OI—0:03 mm.

REMARKS. This is the second most common species in the collection. It is easy
to distinguish macroscopically in unworn specimens, and is very distinctive micro-
scopically where its thick cortex and deep vestibules distinguish it from other species.
It is typically Rhabdomesid and I place it in the genus Rhombopora although it has
well-developed hemisepta. The tabulated mesopores are another feature not
normally associated with the genus. Perhaps a new genus should be introduced to
take such species of Rhombopora with hemisepta and occasionally with mesopores.
Such forms are common in both Silurian and Carboniferous rocks of England.

Family RHINIDICTYIDAE Ulrich 1895
Genus PACHYDICTYA Ulrich 1882, emend Ross 1961

In the emended genus Ross (1961 : 338) emphasized the salient features, including
the microstructure of the walls. There is nothing to add to her description.

SILURIAN POLYZOA FROM BENTHALL EDGE, SHROPSHIRE II5

Pachydictya crassa (Hall)
Pl. 5. figs. 6-8.

1852 Stictopora cvassa Hall: 45, pl. 18, figs. 4a—c.
1893 Pachydictya crassa (Hall) Ulrich : 147.
1906 Pachydictya crassa (Hall) ; Bassler : 57, pl. 18, figs. 11-12 ; pl. 21, figs. 14-16.

MATERIAL. PD 4368-76.

DEscRIPTION. Zoaria bifoliate, branching, with apertures in longitudinal rows on
both sides. Very occasionally triangular in cross-section. Narrow strip along edges
of ribbons without apertures. Occasional large zooecia stand out raised up on
surface having the appearance of small volcanoes with central craters surrounded
by side craters.

Zooecia arise on both sides of the mesotheca, which is pierced by numerous tubuli,
and make an angle of about 60° with it, quickly becoming normal to the surface.
The walls consist of a central laminate portion between the zooecia which contains
the tabulate interspaces typical of the genus, and numerous acanthopores, and a
clearer portion adjoining the zooecia. The larger zooecia have diaphragms. Aper-
tures are oval and surrounded by dark rings and the spaces between them contain
numerous small acanthopores. Mesopores wanting.

MEASUREMENTS.
Breadth of zoaria F : , ‘ ‘ 4-5 mm.
Thickness of zoaria 4 : . I-I'°5 mm.
Thickness of zoaria at an oaleneedl a zooecium 22°25 mm.
Breadth of outer strip. : : : : 0-5-0'7 mm.
Number of rows of zooecia_.. F : ; commonly 7
Size of aperture . : 0:25-0'4 mm. X O-I—O-14 mm.
Longitudinal amaenepace- : : : : 0-2-0°3 mm.
Lateral interspace : : 0°3-0:35 mm.
Number of apertures in 2 mm. longitudinally : : : 4
Number of apertures in 2 mm. laterally . , 5 : 5

REMARKS. This is a common species and is easy to pick out macroscopically. It
is notable for the occasional, enlarged zooecia which are, however, similar in section
to those of normal size. It appears to be similar both to Hall’s figures of Stictopora
crassa (1852) and to Bassler’s figures and descriptions of Pachydictya crassa (1906),
though there is no sign of a linear ridge separating the zooecial rows. It differs
from the Llandoverian-Wenlockian P. holmi Hennig (1905: 25, text-figs. 22-32,
pl. 1, fig. 4) in having smaller apertures and less thickness, and in the zooecia having
few diaphragms. Like that species the zoarium is very occasionally triangular in
section. It differs from the Llandoverian P. dichotoma Nekhoroshev (1961 : 156,
pl. 34, figs. 2, 3) in having fewer rows of apertures to a branch. Nekhoroshev noted
this as the main difference between his species and P. crassa (Hall), and stated that
later forms show a reduction in the number of rows.

116 SILURIAN POLYZOA FROM BENTHALL EDGE, SHROPSHIRE
V. ACKNOWLEDGEMENTS

The author would like to record his sincere thanks to Dr. H. Dighton Thomas,
who has always been ready with help and advice, and to Mr. H. Spencer, who has
taken great pains to perfect the photography.

VI. REFERENCES

Astrova, G. G. 1959. Silurian bryozoa from Central and Eastern Touva. Tyvav. Inst.
Paleont. Acad. Sct. U.R.S.S., Moscow, 79 : 1-72, pls. 1-12. [In Russian. ]

BAssLER, R. S. 1906. The bryozoan fauna of the Rochester Shale. Bull. U.S. Geol. Suvv.,

Washington, 292 : 1-137, pls. 1-31.

1911. The Early Paleozoic Bryozoa of the Baltic Provinces. Bull. U.S. Nat. Mus.,
Washington, 77 : I—xxi, 1-382, pls. 1-13.

—— 1952. Taxonomic notes on genera of fossil and recent Bryozoa. J. Wash. Acad. Sci.,
42 : 381-385, figs. 1-27.

1953. Tveatise on Invertebrate Paleontology, Part G. Bryozoa : G1-253. Geol. Soc. Amer.
& Univ. Kansas Press.

BoarpMan, R.S. 1960. Trepostomatous bryozoa of the Hamilton Group of New York State.
Prof. Pap. U.S. Geol. Suvv., Washington, 340 : 1—87, pls. 1-22.

1960a. A revision of the Ordovician bryozoan genera Batostoma, Anaphragma and
Amplexopora. Smithson. Misc. Coll., Washington, 140, 5 : 1-28, pls. 1-7.

Davipson, T. 1881. A Monograph of the British Fossil Brachiopoda, 5, 1 : 65-72. Supple-
ment to the British Silurian Brachiopoda. Palaeontogr. Soc. [Monogr.], London.

Davipson, T. & Maw, G. 1881. Notes on the physical character and thickness of the Upper
Silurian Rocks of Shropshire, with the Brachiopoda they contain grouped in Geological
Horizons. Geol. Mag. Lond. (2) 8 : 100-109.

Epwarps, H. M. & Harme, J. 1851. Monographie des Polypiers fossiles des Terrains palaeo-
zoiques. Arch. Mus. hist. nat. Paris, 5 : 1-502, pls. 1-20.

—— 1854 [1855]. Corals from the Silurian Formation. A Monograph of the British Fossil
Corals, 5 : 245-299, pls. 57-72. Palaeontogr. Soc. [Monogr.], London.

GRAY, J. E. 1848. List of specimens of British animals in the collection of the British Museum,
I. Centroniae ov Radiated Animals. 173 pp. London.

Hatt, J. 1851. New genera of fossil corals from the report by James Hall, on the Palaeont-

ology of New York. Amer. J. Sci., New Haven (2) 11: 398-401.

1852. Natural History of New York. Palaeontology, 2. viii + 362 pp., 88 pls. Albany.

1879. The Fauna of the Niagara Group of Central Indiana. Rep. N.Y. St. Mus., Albany,
28 : 99-203, pls. 1-32.

Hennic, A. 1905. Gotlands Silur-Bryozoer, 1. Avk. Zool., Uppsala, 2, 10 : 1-37, pls. I, 2.

—— 1908. Gotlands Silur-Bryozoer, 3. Avk. Zool., Uppsala, 4, 21 : 1-64, pls. 1-7.

LONSDALE, W. 1839. Jn Murcuison, R. I. The Silurian System: 577-712, pls. 1-27.
London.

McCoy, F. 1849. On some new genera and species of Palaeozoic Corals and Foraminifera.

Ann. Mag. Nat. Hist., London (2) 3 : 119-136, 4 figs.
1851-1855. In SrEpGwicK, A. & McCoy, F. A synopsis of the classification of the British
Palaeozoic vocks, with a systematic description of the British Palaeozoic Fossils in the Geological
Museum of the University of Cambridge. xcviil+661 pp., 25 pls. London & Cambridge.
Moore, R.C. 1929. A bryozoan faunule from the Upper Graham Formation, Pennsylvanian,
of North Central Texas. J. Paleont., Tulsa, 3 : 1-27, 121-156, pls. 1-3, 15-18.

NEKHOROSHEYV, V. P. 1961. Ordovician and Silurian Bryozoa from the Siberian Platform.
Order Cryptostomata. Tvudy vses. nauchn.-isslzed geol. Inst. (VSEGEI), Leningrad, 41:
1-246, pls. 1-37. [In Russian.]

SILURIAN POLYZOA FROM BENTHALL EDGE, SHROPSHIRE Ly,

Nicuorson, H. A. 1879. On the Structure and Affinities of the “‘ Tabulate Corals’’ of the
Palaeozoic Period. xii + 342 pp., 15 pls. Edinburgh & London.

—— 1881. On the Structure and Affinities of the Genus Monticulipora and its Subgeneva. xvi +
240 pp., 6 pls. Edinburgh & London.

—— 1884. Contributions to Micro-Palaeontology. Notes on some Species of Monticuliporoid
Corals from the Upper Silurian Rocks of Britain. Ann. Mag. Nat. Hist., London (5) 13:
117-127, pl. 7.

Nicuorson, H. A. & Foorp, A. H. 1885. On the genus Fistulipora McCoy with descriptions
of several species. Ann. Mag. Nat. Hist., London (5) 16 : 496-517, pls. 15-18.

Oakley, K. P. 1934. Phosphatic calculi in Silurian Polyzoa. Proc. Roy. Soc. Lond. (B)
116 : 296-314, pls. 12-14.

Orpieny, A.D. 1850. Prodvome de Paléontologie stratigvaphique universelle,1. 1x + 394 pp.
Paris.

OweEN, D. E. 1960. Upper Silurian Bryozoa from Central Wales. Palaeontology, London,

3: 69-74, pl. 16.

1961. On the species Orvbignyella fibyosa (Lonsdale). Geol. Mag. Lond., 98 : 230-234,

pl. 14.

—— 1962. Ludlovian Bryozoa from the Ludlow district. Palaeontology, London, 5: 195-
212, pls. 28-32.

Pocock, R. W. & WuITTARD, W. F. 1948. The Welsh Borderland. Brit. Reg. Geol., 2nd ed.
Geol. Surv. Gt. Britain.

QuENSTEDT, F. A. 1878. Petvefactenkunde Deutschlands, 6. ‘Korallen. 1093 pp., 42 pls.
Leipzig.

Ross, J. R. P. 1960. MRestudy of Types of Seven Ordovician Bifoliate Bryozoa. Palaeont-
ology, London, 3 : 1-25, pls. I-10.

—— 1961. Larger Cryptostome Bryozoa of the Ordovician and Silurian, Anticosti Island,
Canada, 2. J. Paleont., Tulsa, 35 : 331-344, pls. 41-45.

STUBBLEFIELD,C.J. 1938. The Typesand Figured specimens in Phillips and Salter’s Palaeont-
ological Appendix to John Phillips’ Memoir on ‘ The Malvern Hills Compared with the
Palaeozoic Districts of Abberley, etc.’ Swmm. Progr. Geol. Surv. Gt. Brit., 1936, 2: 27-51.

Tuompson, J. V. 1830. Zoological Researches, and Illustrations ; or Natural History of
Nondescript or Imperfectly Known Animals, a series of Memoirs. On Polyzoa, a new
animal discovered as an inhabitant of some Zoophites—with the description of the newly
instituted Genera of Pedicellaria and Vesicularia, and their Species. Memoir 5 : 89-102,
pls. 1-3. Cork.

Urricu, E.O. 1882. American Palaeozoic Bryozoa. J. Cincinn. Soc. Nat. Hist., 5 : 121-175,
232-257, pls. 6-8, Io, 11.

—— 1890. Palaeozoic Bryozoa. Geol. Surv. Illinois, 8 : 283-728, pls. 29-78.

—— 1895. On Lower Silurian Bryozoa of Minnesota. The Geology of Minnesota. Final
Report, 3, 1 : 96-332, pls. 1-28. Minneapolis.

Vine, G. R. 1881. Second Report of the Committee consisting of Professor P. M. Duncan,
F.R.S., and Mr. G. R. Vine, appointed for the purpose of reporting on fossil Polyzoa.
Rep. Brit. Ass., London, 1881 : 161-175.

—— 1882. Notes on the Polyzoa of the Wenlock Shales, Wenlock Limestone, and Shales
over Wenlock Limestone. Quart. J. Geol. Soc. Lond., 38 : 44-68.

—— 1883. Notes on the Corals and Bryozoans of the Wenlock Shales (Mr. Maw’s Washings).
Quart. J. Geol. Soc. Lond., 39 : 69-70 (Proc.).

—— 1886. Notes on the Polyzoa of the Wenlock Shales, etc. Part. 1. Pyvoc. Yorks. Geol.
(Polyt.) Soc., Leeds, 9 : 179-201.

—— 1886a. Notes on the Palaeontology of the Wenlock Shales of Shropshire (Mr. Maw’s
Washings 1880). Proc. Yorks. Geol. (Polyt.) Soc., Leeds, 9 : 224-248.

WHITTARD, W.F. 1952. A Geology of South Shropshire. Proc. Geol. Ass. Lond., 63 : 143-197.

PD4239.
PD42306.

PD4241.
PD4242.

PD4267.

PLATE tf

Mitoclema vegularis (Vine)
Vertical section showing simple zooecia curving to the surface. X50.
Solid specimen with apertures occurring in an irregular spiral. x13.
Ceramopora sp.

Vertical section of PD4240 showing vesicular tissue. X50.
Tangential section of same specimen showing apertures with lunaria.

Fistulipora crassa (Lonsdale)

Vertical section of ramose form. X50.

PLATE 1

Bull. B.M. (N.H.) Geol. 10, 4

PLATE 2

Fistulipora crassa (Lonsdale)
Fic. 1. PD4251. Vertical section of PD4250, encrusting form. X50.

Fic. 2. PD4261. Tangential section of another specimen, PD4260, showing lunaria encirc-
ling apertures. X50.

Evidotrypa cylindrica sp. nov.
Fic. 3. PD4269. Vertical section of holotype, PD4268, showing Leioclemid wall structure.
x 50.
Fic. 4. PD4270. Tangential section of holotype showing ringed apertures. 50.

Evidotrypa cava sp. nov.
Fic. 5. PD4285. Vertical section (holotype) showing numerous diaphragms in endozone.
x 50. =
Fic. 6. PD4286. Tangential section of another specimen showing apertures thickly ringed
round, small mesopores and acanthopores. xX 50.

Bull. B.M. (N.H.) Geol. 10, 4 PLATE 2

Fie.

X 50.

FIG.

x 50.

Fic.

Fie.

x 50.

Fic.

x 50.

Fic.

PD4293.

PD4294.

PD4303.

PD4304.

PD4311.

PD4310.

PD43106.

PD4317.

PLATE 3
Evidotrypa sp.
Vertical section of PD4292 showing both thin and expanded portion.
Tangential section of same specimen. X50.
Leioclema densiporum sp. nov.
Tangential section of holotype, PD4302, showing numerous acanthopores.
Vertical section of holotype showing thick walls. x50
Leioclema asperum (Hall)

Vertical section of PD4309 showing mesopores and stout acanthopores.
Tangential section of same specimen showing large acanthopores. X 50.

Leioclema vamosum sp. nov.

Vertical section of holotype, PD4315, showing Leioclemid wall structure.

Tangential section of holotype showing few large acanthopores. 50

PLATE 3

Bull. B.M. (N.H.) Geol. 10, 4

te: kt

Fig. 1. PD4321.
walls. X50.

Fic. 2. PD4321.
x 50.

Fic. 3. PD43209.

Fic. 4. PD4330.
mesopores. X50.

Fie. 5. PD4298.

Fic. 6. PD 4297.

PLATE 4

Nicholsonella parva sp. nov.
Vertical section of holotype showing tabulate mesopores and shadowy

Tangential section of holotype showing mesopores and acanthopores.

Hallopora elegantula (Hall)

Vertical section of PD4328 showing Leioclemid wall structure. x50.
Tangential section of same specimen showing apertures separated by

Hallopora striata (Hall)

Vertical section showing Atactotoechid wall structure. x50.

Tangential section of another specimen showing integrate walls. 50.

Bull. B.M. (N.H.) Geol. 10, 4

PLATE 5

Monotrypella benthallensis sp. nov.

Fic. 1. PD4337. Vertical section showing Atactotoechid wall structure. X50.
Fic. 2. PD4335. Tangential section of holotype, PD4334, showing different sizes of
apertures and integrate wall structure. 50.

Rhomboporva mawi sp. nov.

Fic. 3. PD4351. Vertical section of holotype, PD4350, a specimen with a thick exozone.
Note the tabulate mesopores. X50.

Fic. 4. PD4365. Vertical section through another specimen with a relatively thin exozone.
Note the hemisepta. x 50.

Fic. 5. PD4366. Tangential section of another specimen showing acanthopores. X50.

Pachydictya crassa (Hall)

Fic. 6. PD4369. Tangential section. Note rings round apertures and numerous acantho-
pores. X50.

Fic. 7. PD4368. Transverse section of another specimen showing tabulate zooecium and
tubules in mesotheca. X50.

Fic. 8. PD4370. Vertical section (of another specimen) of a piece which has broken away
from the mesotheca. This shows outer wall (a) and inner wall (6) embedded in a translucent
wall (c) which adjoined the mesotheca. Specimen is encrusted by a Fistuliporid (d). X50.

Bull. B.M. (N.H.) Geol. 10, 4

PLATE 6

Monotrypa flabellata Owen

Fic. 1. PD4344. Vertical section showing zooecia with integrate walls arising from a
basal epitheca. X50.

Fic. 2. PD4343. Tangential section showing a group of zooecia with larger apertures
(lower right) adjoining those of the more normal size. X50.

PLATE 6

Bull. B.M. (N.H.) Geol. 10, 4

S. ARCHANGELSKY

_ BULLETIN OF

_ MUSEUM (NATURAL HISTORY)
Ren Vol. 10 No. 5

Rare. LONDON: 1965

FOSSIL GINKGOALES FROM THE TICO FLORA,
SANTA CRUZ PROVINCE, ARGENTINA

IB;

SERGIO ARCHANGELSKY

Museo de Ciencias Naturales, La Plata
Research worker, National Research Council, Argentina

Pp. 119-137 ; 5 Plates ; 19 Text-figures

BUELETIN OF
THE BRITISH MUSEUM (NATURAL HISTORY)
GEOLOGY Vol. to No. 5
LONDON: 1965

THE BULLETIN OF THE BRITISH MUSEUM
(NATURAL HISTORY), ‘nstituted im 1949, 1s
issued in five series corresponding to the Departments
of the Museum, and an Historical serves.

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.

This paper is Vol. 10, No. 5 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)

Issued June, 1965 Price Twenty-eight Shillings

FOSSIL GINKGOALES FROM THE TICO FLORA,
SANTA CRUZ PROVINCE, ARGENTINA
By SERGIO ARCHANGELSKY

SYNOPSIS

The present paper deals with Lower Cretaceous Ginkgoales and associated seeds found in
the Ticé Flora, Santa Cruz Province, Argentina. The plants were collected from two different
localities, Tico Amphitheatre and Bajo Tigre Estancia. Two new species of leaves are referred
to the genus Ginkgoites (G. tigvensis and G. ticoensis). A female structure found in close asso-
ciation with G. tigvensis is referred to a new genus, Karkenia. Fragments of short shoots
probably belonging to the same plant and roots found in the same bed are described. A new
seed, associated with G. ticoensis, is described as Allicospermum patagonicum sp. n.

INTRODUCTION

THE material described in the present paper was collected by the writer during the
years 1958-59 (Tico) and 1962-63 (Bajo Tigre). The first two excursions covered
only the Tico Amphitheatre and included only a short visit to a new exposure with
similar sediments bearing mummified plants in the Estancia Bajo Tigre. A longer
excursion to this new locality was undertaken in 1962 when it became evident that
the same formation known from Punta del Barco and the Ticd Amphitheatre
extended N. and E. to cover a large area. In the Bajo Tigre the fossil plants are
preserved in the same way as in Tico and occur in similar lenticular beds of brownish
colour which makes them easy to distinguish in the field from the typical, mostly
sterile, white tuffs. Several plant beds were discovered, the three main ones con-
taining (1) Ginkgoites and other remains described here, (2) Piilophyllum and associated
conifers of Brachyphyllum type, and (3) one long-leaved conifer with male and female
cones in organic connexion, together with abundant freshwater mollusca.

In 1963, further collecting in the same locality was undertaken, and several short
excursions made to new areas which confirmed the extension of the same formation
more than 100 km. northwards. Among the new localities discovered, one yielding
excellent plant mummifications is known as Bajo Grande situated a few kilometres
SW of the Petrified Forest of Santa Cruz (containing the petrified female cones of
Araucanria mirabilis Speggazini). In Bajo Grande a rich plant association was
found composed of many conifers (some with cones), Bennettitales and cutinized
fern-like fronds, but no Ginkgoales.

As a result of these excursions, a large amount of material has been collected, the
description of which will take some years of future work. The age of the plant
bearing beds (and the whole formation) has previously been considered as Upper
Jurassic or Lower Cretaceous. However, the pollen content of the strata seems to
confirm a Lower Cretaceous age, possibly Barremian to Hauterivian and the flora
may well be the last plant association before the advent of the Angiosperms ; it
may mark the uppermost limit of survival of some important fossil taxa.

Little is known about Upper Mesozoic Ginkgoales in Argentina. The most
comprehensive papers deal mainly with the abundant Triassic impressions. There
are no records of Ginkgoites in the Lower and Middle Jurassic strata, but they are

122 FOSSIL GINKGOALES FROM TICO, ARGENTINA

present in Upper Jurassic and Lower Cretaceous formations from Lago San Martin,
Santa Cruz Province and from Graham Land, Antarctica (Halle 1913). Other
records are from Tertiary strata in Chubut Province, Patagonia. The present
material fills a gap in the knowledge of the cuticle of Ginkgoites leaves in Argentina
and throws further light on the development of the female structures in this group.

SYSTEMATIC DESCRIPTIONS
GINKGOALES
Genus GINKGOITES Seward 1919
Ginkgoites ticoensis sp. n.
(PI. a, figs..5,'05; Pl 3; figs. 19-21 5 Bloat ttew27 ) Lext-tiges1 0)

Dracnosis. Leaves with petiole 1 cm. long x 1 mm. wide ; lamina with radius
of 2-3 cm., divided into 4 segments ; basal angle about 90°. Segments linear to
oblong, 4-6 mm. wide, apices blunt, rounded, sometimes slightly lobed. Veins
conspicuous, dichotomously forked, up to 12 per lobe at a concentration of 2 per mm. ;
margins entire, substance dense, mesophyll thick, transversely cracked. Resin
bodies absent.

Both cuticles of same thickness (1-2, measured in folds). Upper cuticle having
no stomata ; cells polygonal, not forming rows or bands, each cell bearing a strong
hollow papilla ; cells between veins 25-35 in diameter, on veins somewhat rect-
angular or elongated, also bearing papillae. Anticlinal walls straight, delicate,
closely pitted. On veins, lateral anticlinal walls sometimes strongly thickened.
Periclinal walls finely granular ; granules also present on papillae.

Lower cuticle showing bands of rectangular cells along veins and margins, alter-
nating with bands of polygonal cells between veins. Vein bands 6-10 cells wide,
marginal bands more than Io cells wide. Cells along veins 15-20y wide ; lateral
anticlinal walls may be strongly cutinized. Cells between veins polygonal, iso-
diametric, about 20 ; anticlinal walls straight or slightly sinuous, closely pitted ;
periclinal walls finely granular, but not as densely as on upper cuticle. A strong
hollow papilla usually present on each cell, but sometimes absent.

Stomata not placed in files, well spaced, variably orientated, rarely sharing
subsidiary cells. Stomatal apparatus round, more often oval. Subsidiary cell
group round or oval, composed of 5, sometimes 6 similar cells. Encircling cells
usually present but not forming a complete ring, not differentiated from neigh-
bouring epidermal cells. Subsidiary cells sometimes differentiated into polar and
lateral, usually thickened on the edge of the pit, almost closing the pit and forming
a cutinized ring ; occasionally (especially on polar subsidiary cells) there is a strong
hollow papilla. Rarely there is no thickening on subsidiary cells. Guard cells
feebly cutinized or not cutinized, slightly sunken in an oval pit. Mouth of pit 20-25
long. Trichomes absent.

123

FOSSIL GINKGOALES FROM TICO, ARGENTINA

Neaw
ec)

Cio

MED

()
eu

g. I. Lower cuticle showing stomatiferous area.

Fics. 1-6. Ginkgoites ticoensis sp.n. Fi

Slide LP 24, Xitoo. Fig. 2. Upper cuticle. Slide LP 24, x1oo. Fig. 3. Two

stomata with subsidiary cells in contact. Slide LP 24, x500. Figs. 4-6. Stomata.

Slide LP 24, x 500.

124 FOSSIL GINKGOALES FROM TICO, ARGENTINA
Ho.otyre. LP 5800a.

MATERIAL. In addition to the holotype, LP 5801a, 5802, 5803a-5805a ; LIL PB
2559 (4); Brit. Mus. (Nat. Hist.), nos. V.51566, V.51579, V.51926. Slides LP 21-25.

HORIZON AND LOCALITY. Lower Cretaceous, Baqueré Formation, lower member,
Brachyphyllum nirandai Bed ; Ticd Amphitheatre, Santa Cruz Province, Argentina.

Discussion. Ginkgoalean leaves are common in the Mesozoic. There is a
remarkable uniformity in morphological and cuticular characters of the leaves
referred to Ginkgo—Ginkgoites. It is difficult to differentiate species based only on
size and shape of leaves ; the Recent Ginkgo biloba shows a remarkable variation of
such characters. The cuticle probably constitutes a better argument for the differ-
entiation of species. The two species of Ginkgottes described here are clearly
referable to the Ginkgo complex, but the name Ginkgoites is preferred for them
because of the age and the closely associated female structures which are very
different from those known in the Recent genus. As most of the specimens possess
good cuticle, comparisons have been made with those Ginkgoites taxa with similar
preservation.

Harris (1935) described several species of Ginkgoites from the Rhaeto-Liassic of
Greenland. Only two of them are comparable to G. ticoensis. G. acosima Harris
is typically larger (leaf-radius up to 8 cm.) and the distal parts of the segments are
notched. Resin bodies have been observed. The basa! angle of the leaf varies
more than in G. tzcoensis, and concentration of veins per centimetre is 15 against 20
in the Ticé species. The upper cuticle of G. acosima bears a few stomata while none
is present in the Patagonian species.

Ginkgoites taeniata (Braun) closely resembles the Tico species in size and shape.
It differs in having resin bodies and fewer veins per centimetre (or per lobe). The
upper cuticle has few stomata and papillae.

Ginkgo huttont (Sternberg) from the Jurassic of Yorkshire (Harris 1948 : 192) is
a widely variable leaf, and G. ticoensis can be matched in the range of variability.
However, the lobes of G. huttoni are usually wider, having more veins (20-40) than
in G. ticoensis. There are resin bodies and the cuticle is thicker (5 the upper and
2-3 the lower). Stomata and trichomes are also present on the upper cuticle.

Ginkgoites longifolius (Phillips), also from Yorkshire, resembles G. ticoensis in size
and shape. However, there are fewer veins in each lobe and resin bodies have been
observed. Although the thickness of the cuticles is alike, there are no papillae on
the epidermal cells of the upper cuticle in G. longifolius.

Ginkgo ex gr. huttoni (Sternberg) described from the Wealden of East Siberia
(Vachrameev & Doludenko 1961) approaches the Ticé species in having no resin
bodies or stomata on its upper cuticle. But the epidermal cells are larger and
trichomes have been observed on the lower cuticle. Also there are more veins per
lobe (14-18).

FOSSIL GINKGOALES FROM TICO, ARGENTINA 125

Ginkgoites obrutschewt Seward (1911), from the Jurassic of Chinese Dzungaria, has
larger lobes and fewer veins per centimetre. Abundant resin bodies have been
observed and there are no papillae on the epidermal cells of the upper cuticle.

Ginkgoites cf. stbivica (Heer) as described by Yabe & Oishi (1933) from the Middle
Jurassic of Manchuria, has fewer veins per segment and there are rudimentary
stomata on the upper cuticle and no papillae.

Ginkgoites marginatus (Nathorst) as described by Lundblad (1959) is usually
smaller and has no resin bodies in the mesophyll ; there are more veins per lobe
(12). The upper cuticle is without stomata and the epidermal cells have a strong
median papilla. Lundblad (1959) considers Ginkgoites hermelini (Hartz) from the
Liassic of Greenland and G. cf. s¢bivica as described by Yabe & Oishi (1933), to be
synonymous with G. marginatus.

Baiera cf. australis M‘Coy, as described by Halle (1913) from Lago San Martin,
Santa Cruz Province, is similar to G. ficoensis, although Halle did not describe its
cuticle. During a reinvestigation of the original material from Lago San Martin in
the Stockholm Museum of Natural History I found some poor epidermal fragments
which add to the knowledge of this species. The lobes of Halle’s specimens are
more deeply dissected down the lamina than in G. ticoensis and there are fewer veins
in each segment (5-10). The size and shape of the epidermal cells are similar, and
so is the stomatal apparatus. However, no papillae are seen on the cells of the
upper cuticle. The inclusion of the Lago San Martin specimens in Bazera is question-
able (as indeed Halle states). They probably belong to Ginkgoites, because the
leaves are clearly petiolate and the lamina is well developed and not wedged as are
most Bazera species. The Lago San Martin formation which bears these fossils, is
comparable in age to the Baquerd Formation (probably Lower Cretaceous). Some
similar species from both floras have already been mentioned (Archangelsky 1963).
Although the specimens described as Bavera cf. australis by Halle would be better
placed in Ginkgoites, they are specifically different from G. ticoensis, but they may
well be closely related forms.

Ginkgoites tigrensis sp. n.

(Pl. 1, figs. 1-4 ; Pl. 3, fig. 22 ; Pl. 4, figs. 23-26 ; Text-figs. 7-11)

Dracnosis. Leaves with petiole up to 5 cm. long x 2:5 mm. wide. Lamina with
a radius of 1-5 cm., usually divided into 4-8 segments ; basal angle go-180°.
Segments lanceolate with rounded or obtuse apex, 3-8 mm. wide, margins entire ;
veins conspicuous, dichotomously forked, crossing the lamina at a concentration
of about 18-24 per centimetre, up to 15 present in a full sized lobe ; two veins seem
to be present in the petioles. Oval, round or fusiform bodies between veins are
rather few and scattered.

126 FOSSIL GINKGOALES FROM TICO, ARGENTINA

Upper cuticle up to 3-4 thick (measured in folds). Epidermal cells rectangular
on base of lamina and on veins of lobes, 20-25 wide ; between veins becoming
more isodiametric, about 20-25 1n diameter. Anticlinal walls straight, thick, up to
5u, pitted ; periclinal walls with strong ridges, sometimes forming parallel striae,
markedly granular ; papillae occasionally observed. Stomata absent on the petiole
and base of lamina, but present on lobes between veins, not forming rows, variably
orientated, scattered, sometimes sharing subsidiary cells.

Fic. 7. Ginkgottes tigvensis sp.n. Outlines of different leaves to show variation in shape
and size. All x1.

Lower cuticle very thin ; shape and sculpturing on epidermal cells as for upper
cuticle. Anticlinal cell walls thin (1-2), pitted. Stomata present.

Stomatal apparatus on both cuticles circular or oval, with 4—7 similar haplocheilic
subsidiary cells (usually 5-6). Encircling cells sometimes present (apparatus im-
perfectly dicyclic). Sculpturing on subsidiary cells as for common epidermal cells,
except for marked thickening (which occasionally is a papilla) on edge of pit ;
thickenings sometimes fused to form a continuous rim of cutin. Guard cells feebly
cutinized, slightly sunken. Mouth of pit 25—40u long.

Trichomes absent.

HoiotypPe. LP 5806. Counterpart, B.M. (N.H.) no. V.51571.

FOSSIL GINKGOALES FROM TICO, ARGENTINA 127

MATERIAL. In addition to the holotype, LP 5541-54, 5557-71, 5573-74, 55934,
55944, 5631-330), 5636-39, 56434, 5644a, 5647-49), 5650, 5672, 5807-14, 5824-25 ;
British Museum (Nat. Hist.) Nos. V.51490-V.51501, V.51572-78, V.51924-25.
Slides LP 30-40, 145.

Fics. 8-11. Ginkgoites tigvensis sp. n. Fig. 8. Upper cuticle showing distribution of
stomata. Slide LP 30, x1o0o. Figs. 9, 10. Stomata. Slide LP 30, x500. Fig. 11.
Resin bodies. Slide LP 32, x 40.

128 FOSSIL GINKGOALES FROM TICO, ARGENTINA

HORIZON AND LOCALITY. Lower Cretaceous, Baqueré Formation, lower member;
Bajo Tigre, Santa Cruz Province, Argentina.

DESCRIPTION. This species occurs in the Estancia Bajo Tigre, about 10 miles
E. of Ticd. Several fossiliferous beds have been discovered in sediments of similar
colour and texture to those found in the Ticé Amphitheatre. The plants are also
mummified in the same way.

In the bed containing Ginkgoites tigrensis it is the dominant element, the associated
plants being abundant female structures and their dispersed seeds, a few ferns and
some twigs of conifers.

I have included two slightly different types of leaf in G. tigvensis, they both occur
together. Type A has four segments, type B has up to eight. Their cuticles are
very similar but in type B the anticlinal walls are sometimes thinner and the sub-
sidiary cells more often project as papillae instead of forming a continuous rim
round the mouth of a stoma. Sculpturing of the cell surface may be more marked
in type A. Intergradation in these features of the cuticle does, however, occur.

The basal angle of the leaves is usually about 130°, but in small specimens it
is up to 180°.

It is very difficult to separate the delicate lower cuticle from the upper, but a
few fragments were obtained by pulling with nail varnish and then treating them
with dilute KOH.

In the same locality but from a different bed (where Ptilophyllum and Brachy-
phyllum are abundant) I collected two small leaves which may be compared with
the small specimens found in the G. tigrensis Bed (LP 5824-25). Although cuticular
fragments are small and show no important characters, the morphology of the leaves
coincides.

The largest petiole seen (Pl. 1, fig. 4) shows clearly two longitudinal furrows
which I believe are veins.

Discussion. Ginkgoites tigrensis differs from G. ticoensis in shape, size and
cuticular structure. A character in which G. tigrensis differs from all other
Ginkgoites, is the marked tendency of its resin bodies to be concentrated mainly
along the margins of the segments. In all other species they are placed between
the veins but scattered generally over the lamina as in Ginkgo biloba.

Ginkgo huttont (Sternberg) usually has larger leaves and more veins per centimetre ;
it also has trichomes on the epidermis and a thicker cuticle.

Ginkgoites longifolius (Phillips) has a thinner cuticle and no stomata on the upper
side of the leaf. There are also fewer veins per lobe (4-9).

The lobes of G. tigrensis are wider than those of G. marginatus (Nathorst). The
concentration of veins is 4-18 per centimetre while in the Patagonian species it is
18-24 ; also there are more veins per segment in G. tigrensis.

Baiera cf. australis M‘Coy from Lago San Martin, Santa Cruz Province (Halle
1913) is smaller and the lobes are deeply dissected.

Ginkgo biloba is clearly different in shape and size. The distribution of the resin
bodies is also different as well as the stomatal apparatus.

FOSSIL GINKGOALES FROM TICO, ARGENTINA 129

SEEDS AND FEMALE STRUCTURES CLOSELY ASSOCIATED WITH
GINKGOITES LEAVES

ALLICOSPERMUM Harris 1935

Allicospermum patagonicum sp. n.
(Piva, figs’ 7—o Pli5) figs 28 3 ext-tig™ 12)

DiaGnosis. Seeds oval, originally somewhat flattened, with slightly acuminate
apex, typically 4-5 mm. long by 3 mm. wide. Seed consisting of an outer flesh
and an inner stone enclosing various cuticles. Outer flesh about 1 mm. thick
(usually represented by an empty space) ; stone 3-0-3-5 mm. long by 2°5 mm.
wide, with micropilar prolongation 0-5-1-0 mm. long. Surface of stone marked
with longitudinal bulges. On maceration, seed yielding the following cuticles.
(1) The inner (megaspore membrane), densely and finely granular, showing no cell
walls, thick (2~3u in folds) and resistant to maceration. (2) Thin cuticle (I-1-5p in
folds) described as nucellus, partly covering megaspore membrane (probably not
more than one half of it). Cells markedly elongated (120 or more) and 8-I0u
wide. Cell surface flat, not ornamentated. Cell walls straight, becoming thicker
and pitted towards apex ; end walls straight. (3) Poorly preserved thin cuticle
(less than ry in folds), finely granular ; cells isodiametric (15) or slightly elongated
(24u X 5p) with straight walls. Small hollow papillae, one per cell, are sometimes
present. This membrane is regarded as the inner lining of the integument. (4)
Thick cuticle (outer cuticle of integument) enclosing stone and flesh. Cuticle
faintly marked with somewhat isodiametric cells, 10-15 in diameter, with straight
thick walls. Surface may be granulose with many adherences. Stomata absent.

The apex of the nucellus where a pollen chamber might be situated, and a cutinized
lining of the micropylar canal were not seen.

A round scar sometimes seen at the base of the stone probably represents the
hilum.

IFOLOTYPE. LP 5821a.

MATERIAL. In addition to the holotype, LP 5804), 5822a, 5823a, 5863c ; LIL
PB 2559(3) ; British Museum (Nat. Hist.), V.51580—81(2). Slides LP 49-53, 125-129.

Horizon AND Locarity. Lower Cretaceous, Baqueré Formation, lower mem-
ber, Brachyphyllum mivandai Bed ; Ticd Amphitheatre, Santa Cruz Province,
Argentina.

DeEscRIPTION. The seeds are preserved in one of two ways. A. Without
compression. The seed then forms a cavity enclosing the stone which is itself
filled with fine sediment. On the surface of this stone (or possibly the internal cast
of the stone) there are some coaly fragments which yield a few membranes when
macerated. These membranes are situated on the outer surface of the coal. Two
cuticles are usually present. The outer and thicker is similar to cuticle 4 of the
diagnosis, while the inner, poorly preserved, corresponds to cuticle 3 (inner lining of
the integument). Cuticles 2 and I are sometimes also present, adhering to the inner

130 FOSSIL GINKGOALES FROM TICO, ARGENTINA

surface of the coaly fragments. The gap seen outside the coal may be due to the
shrinkage of the stone. B. With compression, but no infilling with sediment.
The seed then forms a disc and it is possible to prepare its cuticles. The flesh forms
a compressed border round the thicker substance of the stone. In such specimens
the megaspore membrane and the nucellus are usually better preserved. Clearly,
the nucellus cuticle is single and was not seen fused to the inner lining of the integu-
ment as in the seed described by Harris (1944 : 427, text-fig. 3D).

Fics. 12-16. Allicospermum patagonicum sp. n. and Karkenia incurva gen. et sp. n.

Fig. 12. Allicospermum patagonicum sp. n. Diagrammatic section of seed to show the
probable extent and position of the different membranes (the stone is dotted). Io.
Figs. 13-16. Karkenia incurva gen. et sp. n. Fig. 13. Diagrammatic section of seed to
show the probable extent and position of the different membranes (small dots represent
the stone ; thick dots are resin cavities). 10. Fig. 14. Cells of nucellus. Slide
LP 42, X 425. Fig. 15. Outermost layer of cells (outer integument) with a few resin
cavities. Slide LP 44, x500. Fig. 16. Cells of the inner integument, faintly marked.
Slide LP 42, x 425.

Discussion. Allicoshermum retimivum Harris from the Jurassic of Yorkshire is
similar in size and shape, though slightly wider. Fine differences are : A. patagoni-
cum has a granulose outer cuticle instead of a smooth one, and the stone, on macera-

FOSSIL GINKGOALES FROM TICO, ARGENTINA 131

tion, yields no reticulum as does A. vetimirum. The Yorkshire species has not
been identified with any leaf. Seeds looking rather like A. patagonicum are associated
with Ginkgoites leaves in various floras and have sometimes been more or less
definitely linked with them. There is, for example, A. xistwm with Ginkgoites
taemiata Harris from Scoresby Sound, Greenland, the cuticles of that seed being
known.

A. patagonicum is associated with Ginkgoites ticoensis in the Brachyphyllum
nmuvandait Bed. Neither of these taxa has been found in other horizons or localities
so far studied.

Fics. 17-18. Karkenia incurva gen. et sp. n. Fig. 17. Reconstruction of the entire
female structure (based on LP 5817). 4:5. Fig. 18. A few inverted ovules inserted
on the main axis. x5. (C. Freile del.)

132 FOSSIL GINKGOALES FROM TICO, ARGENTINA

Genus KARKENIA nov.

which in the language of the Tehuelche

”

The name Karkenia is from “ karken ’
Indians (Southern Patagonia) means “‘ female or woman

DiaGnosis. Oval or elongated seed-bearing structures composed of a central
axis with irregularly disposed pedunculate ovules. Ovules round or oval, curved
(atropous) facing axis with micropylar end, densely packed, composed of four
cutinized membranes belonging to the megaspore, nucellus, inner and outer integu-
ments. Seeds developing a conspicuous stone.

For discussion of genus see below.

TYPE SPECIES. arkenia incurva sp. n.

Karkenia incurva sp. n.
(Pl. 1; fig: 10 3 -Pl. 2; figs: 1a, 145 16, 18%; Pil 5) shes. 20-32) -sihexta hie saeres 1G)

DiAGNosis. Seed-bearing structure up to 4:5 cm. long by 1-3 cm. wide, tapering
gradually towards base and apex. Up to 100 ovules present, densely packed and
irregularly disposed, attached by delicate peduncle to main central axis I-2 mm.
wide. Ovules curved (atropous) with micropylar end close to main axis, round
or oval, 3 mm. long by 2-2:5 mm. wide. Ovules composed of several cutinized
membranes, commencing from the inside : (1) Megaspore membrane ; structureless,
finely granulose, less than Ip thick (in folds). (2) Nucellus membrane ; usually

Fic. 19. Tentative reconstruction based on the dwarf-shoots, leaves (Ginkgoites tigrensis)
and female structures (Karkenia incurva). x2. (C. Freile del.)

FOSSIL GINKGOALES FROM TICO, ARGENTINA 133

closely fused to membranes 1 and 3, extending down to near base, I-1°5y thick (in
folds), showing markedly elongated cells more than 1ooy long by 15u wide, surface
flat, not granulose. At the top, nucellus projecting as a short acute micropylar beak.
(3) Inner layer of integument, probably extending down to near base of ovule,
showing no definite structure but small granules. (4) Outer layer of integument,
faintly cutinized membrane, showing cells about 50u long by 15-25 wide, finely
granulose with occasional small hollow papillae.

Between membranes 3 and 4, small round resin bodies (?) from 2—30y in diameter
occur.

HototypPe. LP 5816.

MATERIAL. In addition to the holotype, LP 5580-84, 5598a, 5599, 5631a—33a,
5635, 5640-41, 5647a—-49a, 5814), 5815a, 5817b-5819; British Museum (Nat. Hist.),
V.51499-503, V.51582-84. Slides LP 41-47, 131-144.

HORIZON AND LOCALITY. Lower Cretaceous, Baqueréd Formation, lower mem-
ber, Ginkgoutes tigrensis Bed ; Bajo Tigre, Santa Cruz Province, Argentina.

DESCRIPTION. Seed-bearing structures, all of one kind, are very abundant in
the bed where Ginkgoites tigrensis occurs. Very few other plant remains are present
in association, all of which are rare : two ferns, one referred to Cladophlebis and the
other to Sphenopteris, and a conifer with long linear leaves. This conifer becomes
more abundant in an upper bed and is known to occur with male and female cones
organically attached to the branches. G. tigrensis and Karkenia incurva are not
only abundant fossils in this bed but are always found in close association.

Many of the fructifications are found entire or slightly broken, but with the ovules
still attached to the main axis. Detached or shed seeds are also very abundant
and they clearly show an egg-shaped stone, finely striated in surface view, with a
marked acuminate apex. The stone is surrounded by the remnants of the outer
fleshy layer about 1 mm. thick. The size of the ovules and the seeds is similar.
There is no trace of the peduncle when the seeds are found isolated, except an
occasional slight thickening at the hilum area.

Several transfers of these fructifications have been prepared. All show the
irregular insertion of the ovules which have no definite phyllotaxis. The ovules
face the axis of the fructifications with their micropylar end, or may be slightly
turned from that position, but never erect. The peduncles are short, not much
longer than the total length of the ovules. Ovules are crowded and compact,
suggesting a cone-like structure. The peduncles are attached only to the hilum
sector of the ovules, where a slight expansion may sometimes be seen ; for the rest
they are free and easy to separate from the ovules. Therefore, the inverted position
of the ovules corresponds to an atropous incurved type. No bracts or laminar
appendages were observed in relation to the ovules or the peduncles. Karkenia
may be defined as having a central axis bearing pedunculate, naked and inverted

134 FOSSIL GINKGOALES FROM TICO, ARGENTINA

ovules. I suggest that the peduncle-ovule structure is morphologically a lateral
branch of the main central axis, being analogous but not homologous to the mega-
sporangiophores of other groups. There is no specialization of the peduncles,
which are merely lateral appendages of the central axis.

As for the cutinized membranes of the ovules, there is no doubt about the shape
and size of the megaspore. The nucellus, closely attached to the megaspore and
sometimes to the inner layer of the integument, is also cutinized down to near the
base of the seed. The micropylar projection is seen as a very short apical extension
of the nucellus and is also cutinized. The micropylar canal was not clearly seen
and no pollen was found in connection. There is doubt about the structure and
extent of the inner lining of the integument. It is a structureless membrane,
sometimes showing very faint marks which may be cell outlines, but this is not sure.
Granules are clearly seen. Also, there is doubt about the structure of the external
surface of the integument, although some cells have been observed. It is similar
to the inner lining of the integument but thicker. Granules and some papillae
were also seen, but there are no stomata. Between these two membranes round
bodies are found isolated or in large groups of 20-30 or more. They may well be
resin bodies, which are more likely to be preserved than the mucilage cavities
present in the Recent Ginkgo biloba. I believe these round bodies are natural
features of the seeds, because they are constant in all the specimens observed and
are of the same type ; often, when detached, they leave a round impression on the
integument membrane.

Associated dwarf-shoots and roots. In close association with Karkenia and
Ginkgoites I have found small, short branches which are probably dwarf-shoots of
the same plant. One of these specimens shows a shoot, 3:3 cm. long by 5 mm. wide,
bearing three dwarf-shoots at intervals of about 0-8 cm. The largest dwarf-shoot
is 1-5 cm. long by 4 mm. wide. The widest seen was I cm. Each of these shoots
is crowded with spirally disposed rhomboidal scars, their longest axis being horizon-
tal. The width of these scars is 1-2 mm. and corresponds to the size of the main
axis of the female structures and the petioles of the leaves. In the middle of these
cushions one or two (?) small circular scars are seen. They may correspond to the
vascular bundles. In its distal part one of these dwarf-shoots shows the remnants
of an axis and a few ovules of the type described for Karkenia. The organic attach-
ment between shoot, axis and ovules may be inferred from the continuous brown
colour which is clearly different from the adjacent light colour of the matrix (PI. 2,
fig. 12).

In close association with the previously described material, many fragments of
roots occur (Pl. 2, figs. 15, 17). Some of them cross the sedimentary layers obliquely,
while others are lying in the sedimentary planes, which, however, are not clearly
defined.

The Ginkgoites leaves, complete Karkenia structures, dwarf-shoots and the roots,
are situated in the boundary of two different sediments ; the lower sector,
bearing most of the organic remains, is a pale brown, fine-grained rock succeeded

FOSSIL GINKGOALES FROM TICO, ARGENTINA 135

by a white coarse-grained sediment. The plants were found in abundance only a
few millimetres above and below this boundary plane. On top of this sector, only
detached Ginkgoalian leaves and fragmentary conifers are present. The presence
of roots may well indicate that the most productive part of the plant bed was
deposited 7m situ, and therefore the plants included have not suffered a long transport.

The roots are composed of a main root about 0-4 cm. wide, giving off secondary
roots, irregularly disposed, at acute or right angles. These secondary roots give
rise to delicate rootlets which are typically crowded with round bodies, 1-2 mm.
in diameter, irregularly situated. No organic remains were found except for a few
carbonized fragments which dissolved completely under maceration. These round
bodies may well belong to some type of mycorrhiza.

MATERIAL. Dwarf-shoots : LP 5587-88, 5642, 56430, 56446, 5645-46 ; British
Museum (Nat. Hist.), V.51575. Roots: LP 5575-79, 55930, 55946, 5598) ;
British Museum (Nat. Hist.), V.51504—-05.

Discussion. Guinkgoites tigrensis, Karkenia incurva and the dwarf-shoots
described may belong to the same plant. The close association and the absence of
other forms which could possibly bear female structures are the only arguments to
suggest this identity.

Comparisons of Karkemia incurva can only be made with the Recent Ginkgo
biloba and with Trichopitys heteromorpha Saporta, a Permian Ginkgoalean plant
whose female structures are inadequately known.

Trichopitys heteromorpha Saporta as described by Florin (1949) has in common
with Karkema incurva the irregular distribution of the ovules on a main axis, and
their inverted position. The number of the ovules is, however, smaller, but the
size is similar. The pedicels which bear the ovules and the main axis are wider in
Trichopitys, and the whole fructification may be longer. Also, the ovules of the
Permian genus are separated and do not form a compact structure as in Karkenia.
The leaves of Tvichopitys are very different, not having a developed lamina. No
dwarf-shoots are known to occur. Neither in Trvichopitys nor in Karkenia is there
a collar at the base of the ovule.

Ginkgo biloba has a female structure composed of one long stalk bearing two
terminal ovules, one of which usually aborts. At the base of the ovules there is a
cup-like structure known as a collar. The stalks are spirally disposed on short
branches (dwarf-shoots) in the axils of young leaves. Abnormal cases do occur ;
one of them shows several ovules irregularly disposed on a main axis. These ovules
have long pedicels but are not inverted. This case suggests, as stated by Florin
(1949), that the ancestors of the group must have been multiovulate structures, like
Trichopitys and Karkenia. The main differences are the absence of a collar and the
inverted position of the ovules, which Karkenia has probably retained from primitive
forms.

The collar is considered by Florin (1949) as a secondary feature, related to the
insertion of the erect ovules, and Karkenia (as well as Trichopitys) is in accordance
because there is no collar but an inverted position of the ovules.

136 FOSSIL GINKGOALES FROM TICO, ARGENTINA

The absence of any laminar structure in direct relation to the ovules, suggests that
the abnormal cases of leaves bearing ovules (found in the Recent Ginkgo) are
secondary phenomena.

Karkenia may well be an intermediate type of female structure (“ flower ’’)
between Tvrichopitys and Ginkgo, having undergone some fusion and reduction
processes since Permian times, but still retaining some primitive features.

It is difficult to establish the degree of relationship between Tvichopitys and
Karkenia. Possibly each of the “ sporangial trusses ”’ of Tvichopitys can be homo-
logous with the single ovule and its peduncle of Karkenia. In such a case, the
‘ sporangial trusses ’’ must have fused to form a compact structure, while the main
axis was strongly reduced. The leaves (sterile telomes) of such branches became
reduced and further disappeared, while they persisted on the entirely sterile branches
During all these changes, probably the “short shoot” habit was attained, with
sterile and fertile telomes clearly differentiated. There is no information about all
these possible intermediate types (Permian—Lower Cretaceous).

It is perhaps easier to understand the processes which followed in order to reach
the Ginkgo type of flower. Every compact structure of Karkenia may be homologous
with the Ginkgo peduncle and ovules. This state was attained by reduction of
Karkenia peduncles, and fusion of its ovules, followed by their erection (forming a
collar as a secondary feature). It may be suspected that the erect position of the
ovules and the formation of the collar, is probably a rather recent phenomenon,
possibly post-Neocomian, when the Angiosperms began to dominate.

Text-fig. Ig is a reconstruction of Karkenia borne on dwarf-shoots, together with
Ginkgoutes tigrensis leaves.

ACKNOWLEDGEMENTS

I would like to express my gratitude to Professor T. M. Harris (Reading University)
for many important suggestions ; to Mr. F. M. Wonnacott for critically revising
the manuscript. Thanks are due to Professor O. Selling for permission to examine
specimens from the Halle Collection in the Stockholm Museum of Natural History.
I am indebted to the National Oil Company (Y PF) and the Alumine Mining Company,
both from Argentina, for help during the field excursions. I am obliged to Mr. L.
Ferreyra of La Plata Museum of Natural History for the photographs which are
included in the present paper.

FOSSIL GINKGOALES FROM TICO, ARGENTINA 137

REFERENCES

ARCHANGELSKY, S. 1963. A New Mesozoic Flora from Ticd, Santa Cruz Province, Argentina.
Bull. Brit. Mus. (Nat. Hist.) Geol., London, 8 : 45-92, pls. 1-12.

Fiorin, R. 1949. The Morphology of Trvichopitys heteromorpha Saporta, a Seedling Plant of
Palaeozoic Age, and the Evolution of the Female Flowers in the Ginkgoinae. Acta Horti
Bergiani, Stockholm, 15 : 79-109, pls. 1-4.

Harte, T. G. 1913. Some Mesozoic Plant-Bearing deposits in Patagonia and Tierra del

Fuego and their Floras. K. svenska VetenskAkad. Handl., Stockholm, 51, 3 : 1-58, pls. 1-5.

1913a. The Mesozoic Flora of Graham Land. Wiss. Evgebn. schwed. Sudpolarexped.

(1901-1903), Stockholm, 3, 14 : 1-123, pls. 1-9.

Harris, T. M. 1935. The Fossil Flora of Scoresby Sound, East Greenland, IV. Ginkgoales,
Coniferales, Lycopodiales and isolated fructifications. Medd. Gvonland, Kjobenhavn,
112 : 1-176, pls. 1-29.

1944. Notes on the Jurassic Flora of Yorkshire, 11. Allicosbermum vetimivum sp. nov.
Ann. Mag. Nat. Hist., London (11) 11 : 424-428, text-fig. 3.

1946. Notes on the Jurassic Flora of Yorkshire, 30. Ginkgoites longifolius (Phillips)
n.comb. Ann. Mag. Nat. Hist., London (11) 13 : 20-24, text-figs. 6, 7.

—-— 1948. Notes on the Jurassic Flora of Yorkshire, 38. Ginkgo huttoni (Sternberg) Heer.
Ann. Mag. Nat. Hist., London (12) 1 : 192-207, text-figs. 4-7.

— 1948). Notes on the Jurassic Flora of Yorkshire, 39. Ginkgo digitata (Brongniart) Heer.
Ann. Mag. Nat. Hist., London (12) 1 : 207-213, text-figs. 7, 8.

Lunpsiap, A. B. 1959. Studies in the Rhaeto-Liassic Floras of Sweden. II:1. Ginkgo-
phyta from the mining district of N.W. Scania. KK. svenska VetenskAkad. Handl., Stock-
holm, 6, 2 : 1-38, pls. 1-6.

OIsHI, S. 1933. A study on the cuticles of some Mesozoic Gymnospermous plants from
China and Manchuria. Sci. Rep. Téhoku Imp. Univ., Sendai (2, Geol.) 12 : 239-252,
pls. 1-4.

SEWARD, A.C. 1911. Jurassic Plants from Chinese Dzungaria. MJém. Com. Géol. St. Pétersb.
(n.s.) 75 : 1-61, pls. 1-7.

VACHRAMEEV, V. A. & DoLuDENKO, M. P. i961. Upper Jurassic and Lower Cretaceous
Floras of the Burenska Basin. Tvud. geol. Inst. Akad. Nauk S.S.S.R., Moscow, 54 : 1-136,
pls. 1-60. [In Russian.]

YasBeE, H. & Olsu1,S. 1933. Mesozoic Plants from Manchuria. Sci. Rep. Téhoku Imp. Univ.,
Sendai (2, Geol.) 12 : 195-238, pls. 1-6.

PLATE 1

Ginkgottes tigvensis sp. 1.

Fics. 1-3. Different leaves showing variation in size, shape and lobation of the segments.
Fig. 1 (LP 5807) X12; Fig. 2 (LP 5824) x2; Fig. 3 (B.M.N.H. V.51571) counterpart of
holotype, X I-I.

Fic. 4. Leaf with long petiole. LP 5552, XI.

Ginkgoites ticoensis sp. n.
Fic. 5. Holotype (LP 5800) x1-5. Fragments of Brachyphyllum mivandai Arch. and
Ruflovinia sierra Arch. are also seen.
Fic. 6. Fragmentary leaf to show venation. LP 5801, X1°5.

Allicospermum patagonicum sp. n.
Fics. 7, 8. Isolated seeds showing carbonized remains of the outer fleshy integument
adhering to the main body. Fig. 7, LP 5804, x8; Fig. 8, LP 5822, x8.
Fic. 9. Several seeds in different positions. LP 5821, X1°5.

Karkenia incurva gen. et sp. n.
Fic. 10. Analmost complete fertile structure (left) together with a leaf of Ginkgoites tigrensis.
B.M.N.H. V.51582, XII.

Bull. B.M. (N.H.) Geol. to, 5 PLATE 1

PILI,

Karkenia incurva gen. et sp. n.

Fic. 11. Enlarged fragment of a female structure, showing main axis (bottom) and several
ovules (some are inverted). LP 5817, 4:5.

Fic. 14. Several fragments of female structures and part of a Ginkgoites tigvensis leaf.
ILIP Fw, S< it

Fic. 16. Fragments of female structures. Towards the left, a small fragmentary pinna of
Cladophlebis sp. is also seen. LP 5815, X1.

Fic. 18. Two isolated seeds. LP 5818, X1°5.

DwarF SHOOTS
Fic. 12. Enlarged fragment showing at the top two seeds of Karkenia incurva. LP 5645,

x 8.
Fic. 13. An almost complete branch showing rhomboidal scars. LP 5643, x 4.

Roots
Fic. 15. Enlarged rootlets showing round bodies attached. LP 5598, x8.
Fic. 17. A root (white arrow) traversing the sediment. LP 5593, XI.

Bull. B.M. (N.H.) Geol. 10, 5 IPL AMINE, 2
ee

PLATE 3

Ginkgoites ticoensis sp. n.
Fic. 19. General aspect of both cuticles (the lower towards the right). Slide LP 24, x 180.
Fic. 20. Lower cuticle. Sector between veins showing distribution of stomata. Slide
P25) <180:
Fic. 21. Two stomata showing strong thickenings overhanging mouth of pit. Slide LP 25,
x 800.

Ginkgoites tigvensis sp. 0.
Fic. 22. Fragment of leaf segment showing three resin bodies near left margin. Slide
ILIP Sy), SX 1).

PLATE 3

Bull. B.M. (N.H.) Geol. 10, 5

PLATE 4

Ginkgoites tigvensis sp. n.
Fic. 23. Fragment of upper cuticle showing few scattered stomata. Slide LP 30, x 180.
Fic. 24. Fragment of upper cuticle showing elongated cells on veins and a sector between
veins, almost devoid of stomata. Slide LP 40, x 180.
Fic. 25. Stoma showing an almost continuous rim of cutin overhanging mouth of pit.
Slide LP 4o, x 850.
Fig. 26. Stoma. Slide LP 30, x 800.

Ginkgottes ticoensis sp. n.
Fic. 27. Stoma showing guard cells slightly cutinized. Slide LP 22, x 800.

Bull. B.M. (N.H.) Geol. 10, 5 PLATE 4

PLATE 5

Allicospermum patagonicum sp. Nn.
Fic. 28. Nucellus membrane (left) and megaspore membrane (right). Slide LP 51, X175.

Karkenia incurva gen. et sp. n.
Fic. 29. Part of a seed showing groups of resin (?) bodies. Slide LP 139, x60.
Fics. 30. 31. Two apical portions of nucelli. Fig. 30, Slide LP 47, x175 ; Fig. 31, Slide
R425 x60; :
Fic. 32. Megaspore membrane. Slide LP 45, 175.

(N.H.) Geol. 10, 5

Bull. B.M.

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THE GENERIC POSITION OF
be OSM UNDITES DOWKERI
CARRUTHERS

ME. J. CHANDLER

Vol. 10 No. 6
LONDON: 1965

imtroGeENERIC POSITION OF
OSMUNDITES DOWKERI
CARRUTHERS

BY
MARJORIE E. J. CHANDLER

Pp. 139-161 ; 12 Pls. ; 2 Text-figures

BULLELIN OF
THE BRITISH MUSEUM (NATURAL HISTORY)
GEOLOGY Vol. 10 No. 6
LONDON: 1965

Issued July, 1965

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Her GENERIC POSHMION OF
OSMUNDITES DOWKERI CARRUTHERS

By M. E. J. CHANDLER

SYNOPSIS

A silicified rhizome from the Thanetian of Herne Bay, Kent, formerly described as Osmundites
dowkevi Carruthers, is now referred to the sub-genus Plenasium of the living Osmunda. This
has been possible owing to the discovery of another better preserved rhizome in Thanet, coupled
with fuller knowledge of the family Osmundaceae. Recent studies by W. Hewitson show
clearly characters which distinguish the three living genera and various sub-genera of the
Osmundaceae. The fossil material is described in detail. Especial attention is given to the
distribution of sclerenchyma in the leaf base and wing stipules. The presence of two protoxylem
groups in the leaf traces within the cortex is demonstrated. The form and number of the xylem
bundles in the cylinder of the rhizome is displayed. A close affinity with rhizomes described
by C. A. Arnold from the Eocene of Clarno, Oregon, is emphasized. A possible connexion
between the Thanetian rhizomes and the common Eocene foliage described as Osmunda lignitum
(Giebel) by Heer and Gardner is suggested in view of the fact that this foliage appears also to
belong to Plenasium.

INTRODUCTION

THE fossil species Osmundites dowkeri Carruthers, based on a single rhizome from the
Thanetian of Herne Bay, Kent, has been known since 1870. It has been described
or mentioned in several publications but without any full and accurate descriptions
of the anatomy. This omission was due in the first place to the fact that the im-
portance of some of these details was not realized but in later works is, in part at
least, to be attributed to the poor condition of the solitary specimen hitherto known.
The published evidence shows clearly the Osmundaceous characters but no attempt
was made previously to establish the true generic position, hence the name Osmun-
dites. The particular choice of name may have been dictated originally by the
inherent mistrust which some palaeobotanists invariably showed about the use of
Recent generic names for incomplete fossil material. Its retention in later work was
due to the immense amount of research needed on living genera before relationship
with Todea and Leptopteris could be excluded. Such research of course involved
the preparation of many slides from rather intractable material to discover what
characters in rhizomes of the different genera were of diagnostic value so that the
knowledge could be applied to fossils. This, coupled with the difficulty of obtaining
for dissection a sufficiently large range of living forms, has been a stumbling block
to further research. But without it no sound opinion on the particular generic
affinity of the fossil could be given.

142 THE GENERIC POSITION OF OSMUNDITES DOWKERI CARRUTHERS
RECENT INCENTIVES TO RESEARCH ON OSMUNDITES DOWKERI

The discovery of a better preserved fern rhizome at Herne Bay by D. J. Jenkins
(Chandler 1961 : 51, pl. I, figs. 1, 2) stimulated the desire to determine the generic
position of Osmundites dowkert more accurately. Fortunately in 1962 Hewitson
published a comprehensive study of the family Osmundaceae demonstrating that
even if the rhizomes only are known, Osmunda can be distinguished from Todea and
Leptopteris. He further showed the range of characters within the Recent genus
Osmunda and how these could be applied in separating its three sub-genera, Osmunda,
Osmundastrum and Plenasium. Hewitson’s research made it clear beyond doubt
that the two Thanetian rhizomes not only belong to the same genus and species but
to the sub-genus Plenasium of Osmunda itself. They should therefore henceforward
be known as Osmunda (sub-genus Plenasium) dowkeri (Carruthers).

SUMMARY OF PREVIOUS WORK AND GENERAL DESCRIPTION OF MATERIAL

Both known specimens are silicified, the holotype being a large piece of a mature
rhizome, whereas the newly found specimen is smaller and younger, apparently
representing the subapical region of a young plant or a young branch of a plant.
The holotype (V. 29629) has twice been described by Carruthers (1870 : 349, pl. 24,
figs. 1-3 ; pl. 25, figs. 1, 3, 4 ; and more briefly 1872 : 52, pl. 2, fig. 8). It was also
mentioned by Gardner & Ettinghausen (1880 : 53) and by Seward & Ford (1903 :
254) but these authors made no attempt to redescribe the rhizome or to discuss its
affinities in any detail. Kidston & Gywnne-Vaughan (1907 : 768) gave a further
account but apart from an excellent description of the diarch roots they added little
to what was already known although they did stress the strong curve taken up by
the xylem of the leaf trace almost immediately after it has left the stele of the stem.
They also gave a diagrammatic transverse section of the wing stipules and leaf base
(1907, pl. 6, fig. 5) which they believed provided the only distinctive specific character
in Osmundaceous stocks. The fungus infested condition of the tissues and resultant
deterioration prevented them from giving any further description of the transverse
section which they show in pl. 4, fig. 21. The magnification of this figure is too
small to show the really significant features which are also much obscured by partial
disorganization both of the specimen and of the slide.

Arnold (1952 : 72), in describing two Osmundaceous rhizomes from the Eocene
Clarno Beds of Oregon, referred briefly to Osmundites dowkeri because it closely re-
sembled his new species, Osmundites Chandleri, in the strong curve of the emergent
leaf trace. Nevertheless he stated (p. 75) that the two were so remote geographically
and geologically as not to justify even a consideration that they might be the same.

In both Thanetian specimens, as in all Osmundaceae rhizomes, the small true stem
is surrounded by a thick mantle of spirally arranged leaf bases which accounts for
most of the thickness seen. In neither is evidence of fronds or fructifications
preserved. Hewitson (1962: 88) confirmed Kidston & Gywnne-Vaughan’s views
as to the importance of the distribution of sclerenchyma in the leaf bases and
demonstrated that this character could be used to discriminate between species,

THE GENERIC POSITION OF OSMUNDITES DOWKERI CARRUTHERS 143

sub-genera and genera. On the evidence of petiole base structure it can be stated
definitely therefore that the two Herne Bay specimens are specifically and generically
identical despite differences of size and age. The specimen V. 29630 is much better
preserved than the original holotype. Added to this the late W. N. Croft prepared
from it an exceptionally fine thin section for he was a master craftsman in this as in
all such matters. The better preserved material is therefore described here, before
considering the detailed characters still visible in the holotype, for it has much to
contribute towards the fuller understanding of the larger older rhizome.

DETAILED EXAMINATION OF V.29630

General Considerations.

The rhizome found on the shore at Hampton, Swalecliff, Herne Bay, and like the
holotype presumed to come from the Thanetian was figured by Chandler (1961 : 51,
pl. 1, figs. 1, 2) to show the gross characters. The maximum length preserved was
53:2 mm. and the diameter 35 x 45 mm. The rhizome broadens slightly upwards
the maximum diameter at the lowest point being only about 27 mm. The cross
section is elliptical. The outer surface has been abraded to such a degree that the
stipes above the stipule wings and the extreme upper ends of these wings have
always been removed. The upper surface of the specimen is a deep basin-like
depression with rim of unequal height owing to differential breakage and abrasion.
The form of this basin is dictated by the angles the stipe bases form with the true
stem, about 23°. Such a narrow angle is most nearly approached in the living sub-
genus Osmundastrum (15°-25°) but this has proved to be very unlike the fossil in
other respects. In Plenasium the corresponding angle is 30°-45° ; in Osmunda
(sub-genus) 25°—40° ; in Todea and Leptopteris about 30° (Hewitson 1962: 73).
The walls of the basin are formed by an amorphous silica casing which must have
filtered in solution into the interstices between the silicified petiole bases. Asa result
the true ventral surfaces of petioles and wing stipules are not exposed except in
minute patches where the casing has chipped away. The length and form of the
wing stipules cannot therefore be recorded but the 30 mm. depth of the basin with
wing stipules still in transverse section on its upper rim indicates that they must
have been more than 30 mm. long. The bottom of the basin is formed by pith,
xylem cylinder and amorphous silica occupying the space once filled by cortex, this
tissue having disappeared. The basin like form of the upper end of the specimen
indicates that growing tip and younger leaves had been torn away prior to fossiliza-
tion leaving the tougher tissues of the somewhat older leaves just below. These
leaf remains have become silicified cell by cell around the true stem. A similar
basin was seen in Todea barbara when tip and youngest fronds were removed. After
silicification superficial chemical action appears to have operated differentially in
the apical region. The silicified xylem cylinder with protruding roots has been left
in relief by etching out most of the inner cortex. The cavities resulting from this
etching are now filled by redeposited coarse irregular grains of silica. The silicified
leaf traces beyond the outer cortex are structurally intact except that the stout

144 THE GENERIC POSITION OF OSMUNDITES DOWKERI CARRUTHERS

cylinder of sclerenchyma which delimited each has been dissolved leaving cylindrical
or variously distorted hollows. These reproduce the irregular forms of the leaf
stipes in section. The siliceous casing which penetrated between the stipes now
remains as a complicated upstanding network (Pl. 5, fig. 11). Within the casing
are embedded hairs, roots and wing stipules all full of structural detail. The re-
moval of what in the living plant was the strongest and most resistant part of the
stipe niay be due to incomplete penetration by silica of the dense thick walled
sclerenchyma cells. These changes are secondary and purely superficial phenomena
for the sclerenchyma cells are perfectly preserved inside the rhizome as shown in a
section about half way down the specimen. But even inside the rhizome the
parenchyma of the inner cortex has gone, its place being taken in the slide by amor-
phous silica except in one small patch. The slide (V.29630a) is the outcome of the
late W. N. Croft’s technical skill and patience. He describes its preparation in his
working notes in the following words : “ ground one side of slide flat. Treated this
with polystyrene with much solvent (benzene) in which alizarin had been ground.
Scraped off dried crust with razor blade. Examined surface with binocular after
wetting with cedar oil. Staining was fairly satisfactory stain having been taken up
by some of the xylem strands, although patchily. Hardening of slice was in any
case necessary as it was somewhat porous ”’

V.29630 was clearly a relatively young rhizome for its stipes were soft and the wing
stipules flexible. Hence the regularity of arrangement seen in the firm older holo-
type is not present. (cf. description of stipes and wing stipules on p. 146).

Anatomical Structure.

The Pith, about 1:5 to 2 mm. in diameter, is formed of typical parenchyma as seen
in transverse section (part only being represented by amorphous silica). The cells
are commonly 0-05 to 0-1 mm. in diameter, rarely 0:14 mm. At the circumference
of this tissue there are a few rows of cells, varying in number, only about half this
size. Some of the larger cells towards the circumference show dark staining. In
view of the limited material, no longitudinal section is available.

The Xylem Cylinder and Leaf Traces. The counting of the xylem bundles which
form the cylinder has been carried out consistently in all sections examined whether
of this or the holotype and in accordance with a plan suggested by Hewitson to
secure uniformity of treatment. Without such a plan the number would vary
considerably with the personal factor. Hewitson, throughout his research, treated
bundles connected by even a single tracheid as one. Otherwise, he explains, “cases
are encountered where it is difficult to make a decision’’. On this basis there are
twenty strands in V.29630a, a large projecting horse-shoe trace being regarded as
one although one of its limbs is almost but not quite severed from the arc (Pl. 2,
fig. 3; Pl. 3, fig. 6). A noticeable feature in the xylem ring is a somewhat oblique
horse-shoe on a radius at right angles to the larger horse-shoe above described. It
has one limb completely separated (counted separately therefore) the remaining one
forming a query-shaped bundle with the hook towards the circumference of the stem
(Pl. 3, fig. 6). On the opposite side of the xylem ring (below right) is a query-shaped

THE GENERIC POSITION OF OSMUNDITES DOWKERI CARRUTHERS 145

pair of bundles with adjacent hooks (PI. 2, fig. 3 ; Pl. 3, fig. 5). There is also a
query-shaped bundle bending to unite with an oval bundle (PI. 2, fig. 3 at 2 o’clock).
Various stages of the development of one of the large horse-shoes from the fusion
of two query-shaped ones can be seen in the slide. In addition there are a number
of pointed or pointed-oval bundles one or two of which show a tendency to be hooked
on account of a slight excavation of the outline on one radial margin.

The development of leaf traces can be admirably seen by comparing slide V.29630a
(Pl. 2, fig. 3) with the smooth lower surface of V.29630 from which it was cut, this
surface representing a slightly higher level in the rhizome (PI. 4, fig. 7). The largest
horse-shoe strand of the slide has separated into two distinct bundles each with a
small median notch on its inner side (PI. 4, fig. 7). A completely separated deeply
C-shaped leaf trace formed by the separated apex of the horse-shoe has already
passed into the outer cortex. All departing leaf traces have a pronounced C-shape.
Within the inner cortex of the slide one leaf trace shows an initial stage of separation.
Others are completely detached. The outer limit of the five-sided light coloured
inner cortex is easily traced (Pl. 2, fig. 3). Its sides, slightly concave, alternate with
sharp angles. They stand out clearly from the darker coloured outer cortex
surrounding it and forming the outermost part of the true stem. The outer cortex
is in its turn readily distinguished from the leaf sheath by its darker colour and by
the delimiting sclerenchyma of the leaf bases seen wherever an included leaf trace
projects in any degree at all beyond the cortical tissue (Pl. 1, fig. 2). The structure
of the outer cortex appears to be homogeneous with well preserved parenchymatous
cells except as stated above where the bounding sclerenchyma of projecting leaf
traces is developed externally.

There are two protoxylem groups in all traces within both regions of the cortex.
They are visible at the inner angle of each arm of the C-shaped xylem strands (PI. 2,
fig. 3; Pl. 4, figs. 8,9; PI. 5, fig. 10). In thin sections they are not very easy to
detect at first because of the blurring resulting from the oblique sections of leaf trace
in which the cells themselves are also frequently tilted slightly by the grinding
processes. This is more or less inevitable for leaves arising at an angle from the
central xylem cylinder are bound to be sectioned somewhat obliquely in a transverse
cut across the rhizome axis. In slide V.29630a a trace in the outer cortex on the
opposite side of the xylem cylinder to the large horse-shoe strand clearly shows one
of its protoxylems as a group of about six small cells at the inner angle of one limb
(Pl. 2, fig. 4) while the second is seen in a blurred section in a corresponding position
on the other limb. By tilting the slide slightly under the microscope a true cross
section of a trace in the inner cortex which has just separated from the stele can be
observed. It lies adjacent to roots (Pl. 3, fig. 5). By using strong reflected light
on the polished solid surface of V.29630 from which the section was cut two proto-
xylems are more readily apparent under the microscope on traces within the true
stem for here the details are not blurred by tilting of the cells (Pl. 4, figs. 7-9). In
both xylem strands and leaf traces the position of the protoxylem may further be
indicated by a slight elongation and convergence of the adjoining metaxylem strands
in transverse section (PI. 2, fig. 4 ; Pl. 3, fig. 5).

146 THE GENERIC POSITION OF OSMUNDITES DOWKERI CARRUTHERS

The number of leaf traces in the cortical region is regarded by Hewitson as of
some importance. He counts only those traces which are actually free from the
stele but whose outer limits, as shown by absence of sclerenchyma ring, do not
project beyond the outer cortex (see p. 145). The slide shows four leaf traces in the
above restricted sense of which two lie wholly in the outer cortex. For living
Osmundaceae Hewitson (1962 : 73) gives the following figures :

Sub-genus Plenasium 3 to 8 traces (o to I inner cortex ; 3 to 8 outer)

Sub-genus Osmunda 8 to 14 traces (2 to 4 inner ; 5 to II outer)
O. lancea is exceptional with 12 to 22 (1 to 5 inner; 11 to15
outer)

Sub-genus Osmundastrum 11 to 27 traces (4 to 12 inner ; 7 to 15 outer)

Genus Todea 6 to 12 traces (2 to 5 innner ; 3 to 8 outer)

Genus Leptopteris 4 to 15 traces in small rhizomes in two of the three
living species (0 to 3 inner ; 3 to 13 outer) 9g to 27 traces (ina
large rhizome of L. superba) (0 to 8 inner ; 4 to 20 outer).

As can be seen the numbers vary in the different genera and sub-genera. The
closest to the fossil is Osmunda (Plenasium) banksiaefolia with four traces in the
entire cortex but differing in that there are none in the inner cortex and four in the
outer.

The Leaf Mantle. Outside the true stem in the leaf mantle, the newly departed
leaf bases still show two protoxylem groups with C-shaped or reniform xylem bands
(Pl. 1, fig. 2 ; Pl. 2, fig. 4, bottom right). Passing towards the circumference of the
rhizome, i.e. in a position equivalent to a higher level on the emerging stipes, the
traces develop a broader larger opening on the adaxial side, gradually becoming
broader and flatter themselves (Pl. 1, fig. 1). As a result of this development the
cutermost, oldest, petioles preserved in the mantle have a broad xylem band with
incurved ends and wide opening. In these older outer stipes the protoxylem has
divided into a number of separate strands which are seen in section lying along the
inner concave outline of the xylem band. (PI. 5, fig. 12; Pl. 6, fig. 14, where the
strands are just visible in the photographs as deeply stained patches. They are
very clearly seen in the slides themselves).

As in all Osmundaceae, petioles which have emerged from the stem are surrounded
entirely by a stout thick ring or ellipse of sclerenchyma often about 0-14 to 0:34 mm.
thick (Pl. 5, fig. 12). In the emerging traces still partly embedded in the outer
cortex this sclerenchyma belt is obvious only on the protruding outer surface of the
petiole as described (PI. 1, fig. 2). No wing stipules have been preserved on the first
two whorls of petioles outside the stem (PI. 6, fig. 14 below, left) but in subsequent
whorls of the loosely arranged and somewhat flexible young stipes the’ stipules are
much twisted and curved. Some stipes are tangentially compressed and radially
elongate with much distorted xylem as seen in section (PI. 6, fig. 14 right), others are
narrow and elongate tangentially (PI. 6, fig. 14 left, above and centre).

On first emerging typical stipe dimensions are as follows, the tangential measure-
ment being given first in every case : 2°55 by I'I4 mm. ; 3:34 by I'I4 mm. ; 3:07

THE GENERIC POSITION OF OSMUNDITES DOWKERI CARRUTHERS 147

by o1r mm. Radially elongate stipes are 2-39 by 2:28 mm. ; 3:07 by 2:28 mm.
At the extreme circumference typical measurements are: 8 by 7 mm. ; 3°5 by
42mm. ; 7 by 28mm. ; 2:55 by 7mm. One of the largest outermost stipes lies
parallel with the greatest diameter of the elliptical section and has a total breadth of
about 26 mm. of which the wings measure 8 and 9 mm. respectively. The maximum
radial diameter of this leaf base is 4-5 mm. The wing stipules are formed of coarse
celled light brown parenchyma with scattered, distinctly separated, patches of
sclerenchyma as seen in transverse section (representing the cut ends of long scleren-
chyma strands). The patches lie mainly at one level in the wing but are sometimes
seen at different levels where the wing is thickest (Pl. 5, fig. 12 ; Pl. 6, fig. 14).
There may be from six to nine patches in each wing but apparently the number is
variable. Towards the thin lateral extremities of the wings the sclerenchyma
patches diminish progressively in size. Sclerenchyma has also developed within the
stipe itself starting in the young leaf base at the apex of the bay on the adaxial side
of the stele. Initially only a few sclerenchyma cells are seen in this position. How-
ever passing upwards, as the leaf develops, this small patch increases in size and later
divides into three as can be observed in stipes a little further out in the mantle.
Later still when the trace broadens the sclerenchyma forms several partly united
patches lying near the inner curve of the xylem. Towards the circumference of
the section it has again broken up to form distinct separated patches as is clearly
shown in PI. 5, fig. 12, lowest stipe, and Pl. 6, fig. 14. More sclerenchyma occurs
within the sclerotic ring of the petiole base on both the adaxial and abaxial sides
of the xylem as well as laterally. Many small scattered quite separate patches are
visible (Pl. 5, fig. 12 ; Pl. 6, fig. 14).

SUMMARY OF CHARACTERS WHICH INDICATE RELATIONSHIP WITH
OSMUNDA, SUB-GENUS PLENASIUM IN V.29630

The features described above distinguish the specimen unmistakeably from Todea
and Leptopteris in the light of Hewitson’s researches. Moreover certain characters
ally it with Osmunda and within that genus with the sub-section Plenasium. These
characters are :

The distribution of the sclerenchyma in wing stipules and leaf base.

As described above. The interrupted character of the adaxial sclerenchyma
adjacent to the leaf trace is encountered in the Japanese and Chinese species Osmunda
(Plenasium) banksiaefolia (Presl) Kuhn. The sub-genus Osmunda has, in contrast,
a long continuous sclerenchyma band in each wing in two of the Recent species
and in all three (Osmunda regalis, O. japonica and O. lancea) little or no scattered
sclerenchyma within the continuous sclerenchyma ring, nor is the adaxial scleren-
chyma associated with the leaf trace arranged as in the fossil (cf. Hewitson 1962, fig. 7
A,B,C). In the sub-genus Osmundastrum the continuous sclerenchyma ring is very
distinct from that of the fossil in that it is formed of two kinds of sclerenchyma.
Todea, although it has scattered sclerenchyma within the wings and continuous

148 THE GENERIC POSITION OF OSMUNDITES DOWKERI CARRUTHERS

ring of the stipe, lacks any sclerenchyma on the adaxial side of the leaf trace in
Hewitson’s material while Kidston & Gywnne-Vaughan (1907, pl. 6, fig. 7) show,
diagrammatically, only a very weak and limited development of such sclerenchyma
in Todea barbara. Leptopteris has either a few well developed sclerotic patches in
each wing or numerous very poorly developed strands, but within the continuous
sclerenchyma ring of the stipe scattered strands are lacking in all species.

The xylem characters.

Especially the two protoxylem groups in the leaf trace prior to its separation
from the stem and the query-shaped bundles with hook directed towards the outside
in the xylem cylinder. Two protoxylem groups in such positions are normal in
all Plenasium species in which also, as in the fossil, the xylem trace has a marked
C-shape immediately after it departs from the stele. Hewitson records having seen
one specimen of Osmunda regalis from India with two protoxylem groups but this
is a rare condition in the sub-genus Osmunda. In view of the other Plenasium
characters which the fossil shows it seems reasonable to regard its two protoxylems
as indications of this sub-genus rather than as an aberrant type of the sub-genus
Osmunda which in the other respects it does not resemble. The number of xylem
bundles (twenty) in the cylinder of the stem is rather high for Plenasitum which has
about three to twelve, the sub-genus Osmunda varies from four to eleven, Osmundas-
tvum seven to twenty-two, while in the genera Todea (two to seven) and Leptopterts
(three to twelve) low bundle numbers are found with marked confluence of the bundles.
From species to species in each sub-genus and genus there is some variation. Thus
Osmunda (Plenasium) javanicum has three to eleven, Osmunda (P.) vachellit nine,
Osmunda (P.) bromeliaefolia three to twelve and Osmunda (P.) banksiaefolia four
tonine. In this respect therefore the fossil is specifically distinct with about twenty
to twenty-one entirely separate bundles in the only two specimens seen.

Character of the cortex (Pl. 1, fig. 2).

There is clear separation between the inner and outer cortex and between the
outer cortex and leaf mantle due in the latter case to the sharp definition of the
sclerenchyma bands on the external surface only of the emerging leaf traces as
already described. In Todea and Leptopteris the outer cortex is of two cell types,
the ring around the stipes being thick walled, the remaining tissues of thinner walled
cells with larger lumen. In these two genera, therefore, the sclerenchyma ring is
clear all round the trace while still within the cortex whereas throughout the whole
genus Osmunda as shown above it is only apparent where the stipes protrude.

In the fossil there are four traces in the whole cortex (those, that is, whose outer
limits as shown by sclerenchyma do not project from the cortex) two of which lie
in the inner cortex. The number is determined by the narrowness of this tissue
(external diameter of outer cortex 14 by 9:5 mm. and of the inner cortex 5 by 4-5 mm.)
combined with the sharp angle of departure of the traces (23°). At its greatest
width the outer cortex may be about 3-75 mm. and the inner 0-75 mm. with a least

THE GENERIC POSITION OF OSMUNDITES DOWKERI CARRUTHERS 149

width of about 0-25 mm. The sub-genus Osmunda, and the genera Todea and
(usually) Leptopteris are similar to one another in having up to fifteen traces in the
whole cortex while Osmundastrum differs even more from V.29630 in having eleven
to twenty-seven traces, from four to twelve of these being in the inner cortex which
is relatively wide. Plenasium, on the other hand, resembles the fossil in the small
number of traces (three to eight) with normally nought to one in the inner cortex.
However Hewitson stresses that in this respect the point on the rhizome at which
the section is taken is important, the number of traces increasing with “ an increas-
ing fraction of phyllotaxy and an increasing stem size ’’, but in Plenastum the low
number of traces is real, seven traces being the largest number he had seen in a very
large rhizome of Osmunda javanicum of which one only was in the inner cortex.

RE-EXAMINATION OF THE HOLOTYPE
V.29629, V.29629a and b and slides V.29629c—k and Kidston Collection K.1248
General Considerations.

Having now described and discussed the better preserved specimen it remains
to add a few new facts about the holotype and to indicate the reasons for regarding
both rhizomes as belonging to a single genus and species.

Carruthers in his original description gave natural size drawings but no dimensions
in figures. The specimen when found by Dowker must obviously have been longer
than the 110 mm. which now survive, for so many sections have been cut from the
central region. These inevitably must have meant the grinding away of an appre-
ciable length. The rhizome is now represented by an upper (V.29629a & b) anda
lower (V.29629) portion. The upper part is 47 mm. long, the lower 63 mm.
Carruthers’ figures (1870, pl. 1, figs. I, 2) show the two portions to have been 67 and
73 mm. respectively at that time. This means a loss of some 30 mm. of length from
the two pieces. It is not clear whether two complete sections made by Carruthers
(V.29629c and V.29629h) were cut before his drawings of the hand specimen were
made but probably they were, for the thirty missing millimetres would scarcely
cover the preparation of these two thick slides, of slides V.29629d-g, and of the
Kidston slide also (K.1248, figured Kidston & Gywnne-Vaughan 1907, pl. 4, fig. 21).
K.1248 was prepared commercially by F. Krantz in Bonn in or shortly before 1907.
The production of three serial peel sections by Walton in 1930 must also have
entailed a further slight diminution of the length of the upper fragment, V.29629a
& b. V.29629d was formerly V.2432 and was then entered in the Register (in 1889)
as presented by “‘the late Dr. Millar, March, 1888” (one specimen). V.29629e
(formerly V.40193) is a recent purchase, in 1958, which formed part of the Dufty
Collection. The two slides V.29620f and g are all that remain of four registered in
1902 as “ V.7103 (one specimen) purchased executors of late George Dowker, 1899 ”’
and “‘ V.7104 (three specimens) Sections of Osmundites Dowkeri’”’. The register
indicated that the four slides were all part of V.6126 the former registration number
of the holotype. There is nothing to indicate whether Dowker’s slide, V.7103, was
one of the two survivors or whether both of these survivors belonged formerly to
V.7104. The two slides were apparently already missing in 1952 when the whole
of the Osmundites dowkeri material then extant in the Museum was re-registered

150 THE GENERIC POSITION OF OSMUNDITES DOWKERI CARRUTHERS

TRAcE TRACE

/
N
eet Na —~— — ETCHED SURFACE

hhh hhh hhh dh dh dbdbdbdbbddbddidhdb dbs dddbidddbbbbhbdldidds

3 Peer. SECTIONS ea l¥S5O

VUSTESIESLLIL IIOP IOLILITIMMOOSOLEISOLTLITLELEETIOOISSOLSS,

Ph hhh Lh hehehehe Shh heh hahadaahan cadadeceabcahedhathabentidcthatAachakdkabed V. Pa. 96 29 rI-K.

— — CARRUTHERS Cal87O V:29629H.

UTZ LALLA LL Ad hdd chcieceedebchd bd N ORMAN V-2 9. 62 9 ——@
D777 7 a hdhehed bedded dhhdhhhdchubahchchdhdidddddbddbehhdddbdddth R ELATIVE PosiTio N NOT DETE RNIN ED

PesiITioN OF ORIGINAL CUT

RELATIVE TO SLIDES.

[PIT TTTTOOOOC OCI OC DLL LIL LOL LLL LLL LL LLL

WITTDI OLLIE CIOL LILLIA LL LLL LILO

TOIT ITITIIIO OT OL LOL LILA O LL IDA LALLA AD ALLL LL LLL LLL

IIIT ITIITT TOP COCCI LIL IAAL OIA LLL

NORMAN V.29629 D-E.
RELATIVE POSITION NOT DETERMINED

—— CARRUTHERS Cal870 V.29629¢

— Kiwstron cal7o7 K:1243
—— —PourSHED SURFACE

Fic. 1. Diagram showing relative position in rhizome of slides. For details see text p. 150.
Vertical distances not to scale. Sections cross hatched. V.29629b is the counterpart
half of the sectioned upper fragment of the rhizome so cannot be shown in the figure.

THE GENERIC POSITION OF OSMUNDITES DOWKERI CARRUTHERS 151

as V.29629 (seven specimens). One specimen was the hand specimen (then in two
fragments) and six were slides which can be accounted for as follows : Two Carruthers
slides V.29629c¢ and h (formerly part of V.6126) ; one peel section now V.29629; ;
V.296209d (see above) and V.29629f and g (which alone represent the former four
specimens V.7103-04).

The slides, V.29629d-g appear to predate Carruthers’ work. They have one
feature in common in that all were made by a dealer whose printed label incorporat-
ing the words “ Norman. Preparator’”’ is on each. Probably the slide from
Dowker’s executor was one of Norman’s. Some of these have been reassembled
from other sources (see above). Perhaps the dealer disposed of them in the course
of business ; perhaps also of others not traced. This, although irritating, is relatively
unimportant in that we now have all the information we need. Of Norman’s
available slides V.29620d is far the best as it includes a good tangential arc of the
xylem ring. V.29629e is much disorganized. V.29629f and g are incomplete
portions of the transverse section, f showing a fragment of xylem ring and mantle
on the abraded part of the rhizome and g a piece of the leaf mantle from the broad,
less abraded side of the stem towards the exterior of the rhizome.

Study of the slides themselves, taken together with a consideration of the fore-
going statements, while it cannot give precise distances between the slides shows
their former relative positions in the rhizome. These are drawn diagrammatically
in Text-fig. 1. Although no record of the sectioning appears to have been kept
the sequence of events seems to have been that Dowker, or probably Norman, cut
his rhizome in half and slides were prepared professionally by Norman from the
two cut ends. The two halves of the hand specimen were then transferred to
Carruthers who made two complete transverse sections from the cut ends about
1870. Kidston’s section and the peels were the last to be prepared, two of the latter
having been acquired in 1963. As a result of the way they were made slides from
the upper fragment have the coverslips on the upper side of the slide. Those from
the lower fragment must be reversed with the coverslip lying on the underside of
the slide in order to place them in correct sequence.

The transverse diameter of the hand specimen V.29629 is 45 by 63 mm. Its
leaf mantle is closely compacted. The surface shows the abraded ends of the petiole
bases arranged in a steep spiral of about 35° with the axis. As in V.29630 these
petioles are always worn away below the upper end of the wing stipules. Consequently
neither their transverse sections nor such surfaces as are preserved can show whether
the stipules were fused at the apex across the face of the petiole producing a curved
commissure. Alternatively they could have persisted as two separate wings one
each side of the stipe throughout their length (Text-fig. 2). Kidston & Gywnne-
Vaughan (1907 : 766) believed the presence or absence of this commissure to be the
only constant superficial distinction between Todea stocks on the one hand (including
species now assigned to Leptopteris) and Osmunda on the other, this commissure
being found only in Todea and Leptopteris. Fortunately however it has been shown
by Hewitson that there are other cogent anatomical grounds on which the two
groups can be distinguished.

152 THE GENERIC POSITION OF OSMUNDITES DOWKERI CARRUTHERS

Of the hand specimen the lower and upper portion still remain. The upper with
its rough unpolished surface has also been sectioned longitudinally into two fragments
(V.29629a and b) but the section runs slightly obliquely passing only in the lower
half through the true stem. The grinding processes apparently removed about
6 mm. of the breadth and the pith is only exposed at the lower end of the longitudinal
section. The leaf traces are seen to arise from the stem at about 23°, a figure which
agrees with that deduced for V.29630. A few details of pith, sclerenchyma, xylem
and phloem can be discerned in spite of the difficulty of examining microscopically
such dark material by reflected light. Because the material was so limited, no thin
longitudinal section was cut. The lower piece (V.29629) of the rhizome is deeply
excavated below, only the outer leaf bases remaining at its circumference while the
inner leaf bases have been worn in such a manner as to produce the deep conical
basal cavity. The upper transversely cut and polished surface of V.29629 lies
some 55 mm. above the lowest part of the mantle which forms its circumference.
The transverse section shows the true stem to have a diameter of about 13 mm.
It lay excentrically in the leaf mantle as the result of abrasion prior to fossilization.
Consequently on one side of the specimen all but about two or three layers of the
mantle are missing, whereas eight or nine layers are still present along the opposite
radius of the rhizome (cf. Kidston & Gywnne-Vaughan, 1907 pl. 4, fig. 21). The
least distance between the true stem and the present circumference of the specimen
of the more abraded side is only about 5 mm., but along the opposite radius about
34 mm. The original diameter when the rhizome was perfect would have been
about 80 to 85 mm. along these radii if abrasion on one side had not been so great.
The diameter may well indeed have exceeded the figures suggested for it is probable
that some leaf bases may have disappeared from the least abraded side of the rhizome
also.

Of the transverse sections which still exist, only six show the whole rhizome.
Three of these are valuable peel sections (V.296297, 7, k) which were made very
close together at a high level in the rhizome, where the xylem cylinder was less
damaged than elsewhere and its tissues were less obscured by fungal hyphae. A
comparison of V.296297 and k shows admirably the changes which have occurred
as xylem ring and leaf traces passed upwards (cf. Pl. 8, fig. 16 showing a lower
section, V.296291, and Pl. 9, fig. 17). It is regrettable that the section (K.1248)
figured by Kidston & Gywnne-Vaughan (1907 : 768, pl. 4, fig. 21) was made at a
level where fungal infestation was great and considerable distortion of xylem had
occurred, especially on one side, the result of decay combined with radial compres-
sion along the shortest diameter. This probably explains why the two authors
did not describe the anatomy in greater detail (apart from that of the roots). It
also explains the large number of xylem strands which they reported since the partial
union of some adjacent strands, now counted as one, is obscured by the radial
crushing in this particular section.

THE GENERIC POSITION OF OSMUNDITES DOWKERI CARRUTHERS 153

Anatomical Structure.

The Pith is about 3-5 mm. in diameter, formed of typical parenchymatous cells
frequently about 0-057 mm. in cross section. Around the outer margin there are
about six or seven layers, sometimes only three, of somewhat larger cells which appear
denser and darker in colour but are shown by the longitudinal section to be normal
thin walled equiaxial parenchymatous tissue. In the limited area of pith visible
in the longitudinal section no isolated tracheids have been detected but it must be
remembered that the section does not pass through the central region of the pith.
The pith is continuous with the “‘rays”’ of tissue between the xylem strands and
no indication of an inner endodermis has been seen.

The Xylem Cylinder and Leaf Traces. The xylem cylinder can be examined in
section on the cut surfaces of the rhizome and in seven slides including the peel
sections. It is about 4:5 to 5 mm. in diameter and is formed of about twenty or
twenty-one entirely separated strands, using again Hewitson’s method of counting
(cf. p.144 ). Owing, however, to the radially crushed state of part of the cylinder
as explained above the number cannot be seen in most of the available sections for
on the side where the crushing occurred it is usually impossible to say whether
two adjacent strands are or are not connected as Hewitson specifies “‘ even by one
tracheid’’. The clearest sections for counting are the peel sections (V.296297 and
k). The xylem strands are separated by some five or six layers of radially elongate
parenchyma cells which pass outwards into a parenchyma layer seen in places
surrounding the xylem ring. The strands vary much in shape. Two large horse-
shoes opening inwards project beyond the outer circumference of the cylinder
(Pl. 9, fig. 17). A similar large horse-shoe is seen on the polished lower surface of
the upper fragment (V.29629a) of the rhizome (PI. ro, fig. 18). It also shows a leaf
trace, just separated from the two arms of a horse-shoe lower down in the rhizome
(left in Pl. 9, fig. 17), whose rounded distal end forms the C-shaped trace on this
surface. Occasionally traces are elongate at one extremity owing to the initial
development of a root (Pl. 9, fig. 17 at 2 o’clock). The origin of a pair of roots is
beautifully displayed in peels V.296297 (PI. 8, fig. 16) and7. Some adjacent strands
are united at their inner ends giving rise to a U or V opening outwards. Such a U
is seen to the right of a large horse-shoe (Pl. 9, fig. 17). Two pairs of strands form
two adjacent question marks, one reversed, which are well displayed in the peel
section V.29629 (Pl. 9, fig. 17 top centre, top right). It also shows simple ovals
and three slightly united strands forming an S at 6 o’clock. Between the arms of
united strands there is parenchyma. Most of the obvious tracheids are large
metaxylem elements, smaller ones sometimes occurring at their outer ends. On the
walls of the tracheids several lines of narrow pitted or scalariform thickening can
be seen.

Some difficulty is encountered in the study of the thin sections because the angle
at which the traces spring from the stem again causes transverse sections to cut the
leaf traces slightly obliquely. Further the cells themselves may lie slightly obliquely
on those slides which are more than one cell thick and in the grinding process some

154 THE GENERIC POSITION OF OSMUNDITES DOWKERI CARRUTHERS

disorganization of tissues has occurred. For these reasons many of the cell walls
have a blurred outline. However, as in the case of V.29630a, a slight tilting of the
slide in an appropriate direction sometimes clarifies the cell walls. Once again in
the holotype a study by reflected light of the opaque polished surfaces of the rhizome
itself assists in the understanding of the sections. More especially it is a help in
locating the protoxylems for on the solid surfaces distortion and disorganization
are at a minimum. Any attempt to reduce further the thickness of the sections
might readily lead to worse disorganization. Indeed the thinnest of all, Kidston
Collection slide K.1248 is much disrupted. There is good evidence visible on the
polished lower surface of the upper fragment (V.29629a@) of the rhizome close to the
remaining small arc of xylem at the longitudinally cut edge (Pl. 10, figs. 18-20).
Besides displaying a large horse-shoe trace, it shows V traces opening outwards
(PI. 10, fig. 18) and the initial stages of separation of the rounded end of a horse-shoe
to form a trace. In addition there are well preserved completely separated traces
in the inner cortex while four are still wholly immersed (in Hewitson’s sense) in the
outer cortex. Several of these traces offer unmistakeable evidence of small proto-
xylem strands at the inner angles of the arms of the C-shaped xylem (PI. 10, figs.
Ig, 20) although owing to reflections from the polished surface they are difficult
to show by photography. The evidence is best seen if the examination of these
solid surfaces is made not by artificial light but in bright daylight without direct
sunlight. A low power objective in the microscope shows it clearly. Of the thin
slides the evidence most easily seen is in the peels V.296297 and k.

The successive stages in the development of the leaf trace can be better observed
in the holotype than in V.29630 owing to its wider diameter. As the trace passes
outwards and upwards the xylem sheath becomes more deeply C-shaped or reniform
with only a narrow gap on the adaxial side occupied by about five or six radiaily
elongate cells. This form persists into the outer cortex of the stem. The xylem,
by this time horse-shoe shaped with thickened arms, has a metaxylem which may
be four or five cells thick within the arms but only about two cells or even a single
cell thick at the apex of the horse-shoe. Throughout both regions of the cortex the
leaf trace is surrounded by a clear dark line corresponding to the phloem and its
associated cells. By the time the trace passes into the outer cortex it may be
appreciably larger than it was in the inner. Beyond and surrounding the phloem
in the outer cortex there is an oval or ovate belt of thin-walled parenchyma clearly
delimited from the normal denser tissue of this region (PI. 7, fig. 15). The maximum
diameter of the inner cortex is about 9 mm., its greatest width from the xylem
cylinder to its circumference being about 2 mm. Its outline has seven or eight
points separated by slightly concave sides (Pl. 7, fig. 15; Pl. 9, fig. 17). The
maximum diameter of the outer cortex is about 15 mm. the greatest width between
its inner and outer limits being some 3 to 3:5 mm. _ It also has a seven or eight-rayed
outline. Unlike V.29630 the cell structure happens to be well preserved both in the
inner and outer cortex (Pl. 9, fig. 17). In this mature rhizome the relatively wide
cortex of necessity means that a larger number of leaf traces are sectioned within the
true stem than in V.29630. In the entire cortex about ten to twelve completely

THE GENERIC POSITION OF OSMUNDITES DOWKERI CARRUTHERS 155

immersed traces are visible. In the inner cortex there are six in V.29629¢, five in
V.29629h-7, seven in V.29629k and five on the polished surface of the lower end of
the rhizome (PI. 7, fig. 15). In the outer cortex there are five in V.29629¢, 7, k and
on the polished surface of V.29629 ; six in V.29629h, 7. That there is a somewhat
greater number than in living species of Plenasium is no doubt correlated with the
greater number of xylem strands in the stem cylinder.

Leaf Mantle. Beyond the true stem for the first four or five whorls the emerged
leaves have a more deeply reniform transverse section and then begin to develop a
broader larger opening on the adaxial side (Pl. 11, fig. 21). The development of
sclerenchyma in the bay of the xylem follows the same course as that described on
p- 147 for V.29630. The arrangement of scattered sclerenchyma strands within the
continuous ring of the petiole is also similar (Pl. 12, fig. 22 ; Kidston & Gywnne-
Vaughan, 1907, pl. 6, fig. 5). The sclerenchyma shows less clearly in the photographs
of the thick older slides of the holotype than in the actual slides themselves. It is
much clearer in the thinner Kidston slide (cf. wing stipules Pl. 5, fig. 13 ; Pl. 11,
fig. 21). The identical character of the leaf bases and wing stipules affords clear
evidence that the two rhizome fragments belong to a single species. In contrast to
the young stock in V.29630 the leaf bases are tightly and geometrically packed.
Kidston & Gywnne-Vaughan (1907 : 769) believed that in close proximity to the
true stem the stipules were all concrescent. Since the stipule outlines are perfectly
distinct it seems more probable from experience with other fossils that the appearance
of concrescence was due to infiltration of silica which later formed a cement. In
some newly emerged stipes one wing stipule only may have developed but normally
a pair is seen, the stipules here being very short in transverse section (Pl. 12, fig. 23).
At this stage the diameter from tip to tip may be only 3:5 to 4:5 mm. and the stipe
itself may measure 2:5 mm., the dorsiventral thickness being 2 to 2:75 mm. The
stipules broaden laterally upwards as shown in successively older stipes toward the
circumference of the mantle but, as stated, in no case is a sufficient length of petiole
preserved to show the distal termination of the stipule. This end always appears
to have been removed by abrasion. The breadth of the wing stipules is greatest
and their dorsiventral thickness least where they lie parallel with the greatest
diameter of the rhizome near the circumference (PI. 11, fig. 21). The largest examples
measure 18 mm. in breadth, the actual stipe itself and each wing being about 6 mm.,
the dorsiventral thickness about 2:75 mm. Midway between the extremes of
measurement at the base on the one hand and towards the more distal end of the
stipules as preserved on the other there are measurements of about 7 mm. from tip
to tip with stipe breadth of 3 mm. and dorsiventral thickness of 2:25 mm. In the
highest part of the stipules seen the tips are extremely narrow and may be somewhat
curved ; they are presumably less rigid here on account of their thinness. This
suggests that little of the distal end is missing so that their total length may not
greatly have exceeded 55 mm. A stipule of Todea shown in Text-fig. 2 was 45 mm.
long which suggests that Osmunda dowkeri must have had large stout fronds.

Other Tissues. A sheath of parenchyma surrounds the xylem strands and is
thickest in the outer part of the leaf gap, thinnest opposite the strands themselves.

156 THE GENERIC POSITION OF OSMUNDITES DOWKERI CARRUTHERS

Fic. 2. Two Recent petiole bases. a. Osmunda zeylanica. 8. Todea barbara.

In both the stipe (s¢) flanked by the wing stipules (w) but in Todea these stipules are fused
across the adaxial side of the stipe producing a curved commissure line c. The thick diver-
gent lines and in Todea vertical ones below the commissure, indicate sclerenchyma within.
Clearly a transverse section at the level 7 in the two cases would appear quite different
for in Todea the stipules would lie in front of and quite separate from the stipe, whereas
in Osmunda they would flank it on both sides. This would be apparent in the section of
a fossil stipe at the appropriate level.

Between the xylem strands it constitutes the “ medullary rays ”’ of some writers on
Osmundaceae. It is encircled externally by phloem which is followed by tangen-
tially elongate cells. The large horse-shoes of the incipient leaf traces cause a bulge
in the surrounding parenchyma and phloem. When the leaf traces first appear they
are surrounded by a branch of phloem and tangentially elongate cells (much obscured
by fungi).

V.29620d (PI. 12, fig. 24) shows very clearly the emergence of a root from one angle
of an incipient leaf trace not yet separated from the xylem ring. Tracheids of the
trace can be seen passing directly into the root. Further evidence as to root develop-
ment is shown in Pl. 8, fig. 16 ; Pl. 9, fig. 17.

THE GENERIC POSITION OF OSMUNDITES DOWKERI CARRUTHERS 157
SPECIFIC IDENTITY OF THE TWO SPECIMENS DESCRIBED

It should be noted that the holotype not only agrees with V29630 in the character
of the leaf bases of the mantle but also in the two protoxylem strands of traces
within the cortex, in the form and number of xylem strands in the stem cylinder
and in the deeply curved form of the xylem in the newly separated leaf traces.
Hence all lines of evidence point to the specific identity of the two specimens and to
their affinity with Osmunda rather than with Todea or Leptopteris. Within the
genus Osmunda the relationship is with the East Asian sub-genus Plenasiwm.

SIMILARITY TO OSMUNDITES CHANDLERI ARNOLD

Only one fossil species resembles the Thanetian Osmunda dowkeri at all closely.
It is Osmundites chandlert Arnold from the Eocene Clarno Beds of Oregon, U.S.A.
(Arnold 1952: 68, pls. 7, 8). In this case the resemblance is so close that in spite
of the geographical distance between Oregon and Southern England it cannot be
disregarded. Features they possess in common are the presence of two protoxylem
strands in the young leaf trace of the inner and outer cortex (well seen by reflected
light on the smooth surface of a rhizome kindly supplied by Professor Arnold and
perhaps in Arnold’s specimen 1952, pl. 7, fig. 12), the C-shaped xylem of the newly
emerged leaf, above all the character of the leaf bases both as regards the form of the
xylem band and the distribution of sclerenchyma. In Osmundttes chandler scleren-
chyma within the continuous ring which surrounds the stipe is scattered laterally,
adaxially and abaxially. It also occurs on the adaxial side close to the xylem arc
and that in the outermost leaves preserved appears to break up into distinct strands
as in Osmunda dowkeri although a short distance within it is only partially separated
into about twelve masses. In the outside whorl of the specimen complete separation
had occurred in one or two places and it is possible that larger rhizomes with suffi-
ciently mature stipes would show the same degree of separation that Osmunda
dowkeri displays (cf. also Arnold 1952, pl. 8, figs. 17, 19). Within the stipule wings
of Osmundites chandler: the distribution of distinct sclerenchyma patches is identical
in the two ; most of the patches are arranged in one line, but they sometimes occur
at more than one level. Arnold reports thirty-four oval or horse-shoe shaped xylem
strands in the stem cylinder (cf. Kidston & Gywnne-Vaughan thirty). If Hewitson’s
method of counting were adopted a reduction in this number could be expected but
it is not possible from the published figure to make an accurate count as the focus
of the print does not show whether any of the strands are partially united. Arnold’s
pl. 8, fig. 5 shows a half cylinder in which there appear to be about eleven distinct
strands. The rhizome received does not clarify this point as the cylinder has broken
down on one side. No clear and unmistakeable query-shaped strands could be seen in
this specimen although a tendency for the development of this form may be indicated
where two bundles turn to one another. Some approximation to this form is seen
in Arnold’s pl. 7, fig. 13 below the left-hand limb of the just separated trace. See
also his pl. 8, fig. 15. Large projecting horse-shoes are a conspicuous feature of the
xylem ring. Arnold himself did not press the possible relationship of Osmunda
dowkert and Osmundites chandleri although he commented on the resemblance

158 THE GENERIC POSITION OF OSMUNDITES DOWKERI CARRUTHERS

between them. He considered that the geological and geographical separation of
the sites from which they came was too great to allow of relationship. It must be
borne in mind that distance in these senses does not always exclude specific identity
for as Scott (1954) has already shown and is to show still further (unpublished work),
identical extinct genera and even identical species do occur among the fruits and
seeds of the Eocene Clarno Beds of Oregon and the London Clay of England. As
regards difference of age it is now clear that the Lower Tertiary flora persisted at
least from the beginning of the Tertiary period into the Oligocene. Should the re-
examination of material of Osmundites chandlert confirm the suggested relationship
to Osmunda dowkert then the former should be referred to Carruthers’ species. In
any case it seems reasonably certain that Osmundites chandleri should be transferred
to the living Osmunda and to the sub-genus Plenasium within it.

A POSSIBLE CONNEXION BETWEEN OSMUNDA (PLENASIUM) DOWKERI
AND OSMUNDA (PLENASIUM) LIGNITUM

It is natural at this point to enquire what evidence there is as to the relationship
of the foliage described as Osmunda lignitum (Giebel) with living sub-genera of
Osmunda. ‘The species is represented by beautiful impressions in the Bournemouth
Marine Beds (Gardner & Ettinghausen 1880 : 49, pl. 4, figs. 1-3 ; 1882 : 66) and
by much broken coriaceous remains in the Bovey Tracey Lignite of Devon (Heer
1862: 1068, pl. 55, figs. 4-6; pl. 56, figs. 1-11 ; pl. 57, figs. 1-7) as well as in
numerous Oligocene horizons on the Continent.

In a letter dated 3.8.60 Dr. R. E. Holttum drew attention to the strong resemblance
between Osmunda ligmitum and the Japanese and Chinese species Osmunda banksiae-
folia. This species, he added, had been included in Osmunda javanicum in Synopsis
Filicium (Hk. & Bak.) although probably distinct. Various species included at one
time in O. javanicum are closely related forms belonging to the sub-genus Plenasium.
Gardner & Ettingshausen (1880 : 53) had already noticed the close resemblance
between this fossil foliage and “‘ Osmunda javanicum’”’ which ranged, they noted,
from Kamschatka to Java and Ceylon. At a later date in a Revision of Eocene
Ferns for which Gardner alone was apparently responsible (Gardner & Ettingshausen
1882 : 66), the variations of the “ species’? Osmunda javanicum in the different
latitudinal areas of its range are described. The statement there occurs that, “‘ It
is in the more average-sized pinnae from Formosa, latitude 24° that we meet with
the most absolute identity, as far as the fragments admit of comparison, with our
fossil forms ”’.

Additional support for the view that O. lignitwm belongs to the sub-genus Plena-
sium is provided in Hewitson’s (1962: 61, text-figs. I-4) account and figures of
foliage in the Osmundaceae. While there is general agreement that the species of
Plenasium are in need of reappraisal, it is certain that Osmunda lignitum has its
closest affinities within this sub-genus. Thus the species Osmunda javamicum, O.
vachellit, O. bromeliaefolia and O. banksiaefolia, discussed by Hewitson, are all
characterized, as is O. lignitum, by once-pinnate fronds. The sub-genus Osmunda

THE GENERIC POSITION OF OSMUNDITES DOWKERI CARRUTHERS 159

is excluded from close relationship on account of its bipinnate foliage. (Within it
Hewitson includes Osmunda lancea because it, too, is bipinnate.) His description
of the nervation of this sub-genus shows that it is unlike that of the fossil Osmunda
ligntum. The American sub-genus Osmundastrum (Osmundastrum cinnamomea
and O. claytoniana) although it has once-pinnate fronds is distinguished from
Osmunda lignitum by the deeply dissected pinnae. In Plenasium, whatever the
ultimate renaming of its species, there is some variation of the margin in the pinnae.
It is entire in Osmunda vachellit ; entire or toothed in O. javanicum ; toothed with
narrow pinnae in O. bromeliaefolia ; coarsely toothed with wider pinnae as in the
fossil in O. banksiaefolia where the resemblance is very close indeed. In Osmunda
lignitum the lateral nerves sometimes give off a greater number of forked tertiary
nerves, five or six being shown by Heer on the lower side of the leteral (secondary)
nerve (1862, pl. 57, figs. 1, 4), while in the text he mentions as many as seven or
eight. In his other figures, however, (cf. Heer 1862, pl. 57, fig. 5 for example) there
is complete agreement with Hewitson’s text-fig. 41 of Osmunda banksiaefolia. In
the upper part of the pinnule nearer the tip, O. lignitum shows fewer nerves which
close to the tip may be undivided. Again in O. lignitum, the lowest tertiary nerves
are markedly curved and enter the sinus between adjacent teeth where sometimes
they unite (Heer 1862, pl. 57, fig. 2). Although most of the tertiary nerves actually
spring from a secondary, occasionally a forking nerve arises from a primary one
where it passes directly to the sinus (Heer 1862, pl. 6, figs. 1-5 ; cf. Hewitson 1962 :
65, text-fig. 41). The coriaceous character of the pinnules in itself and quite apart
from a different nervation, serves to distinguish O. lignitum from any species of the
filmy ferns Leptopteris. Todea, too, is quite unlike O. lignitum in that its fronds are
bipinnate while the lateral nerves of the pinnules have a simple fork or may be
unbranched.

The existence of Plenasiwm in the Lower Tertiary of Western Europe on this
entirely independent evidence provided by the foliage, demonstrates at least that
there is no phytogeographical reason why the rhizomes should not be referred to
that sub-genus of Osmunda. It further raises the question whether the rhizomes
and the foliage belong to a single Lower Tertiary species, having regard to the wide
distribution in space and time of many Tertiary plants. There is no direct evidence
in support of such a connexion and probably such will never be forthcoming but the
possibility must be borne in mind. Should the relationship ever be established,
then the specific name dowkeri would have to give place to the earlier designation
lignitum.

SUMMARY OF CONCLUSIONS AS TO THE RELATIONSHIP OF
OSMUNDA DOWKERI TO LIVING OSMUNDACEAE

The Thanetian species, Osmunda dowkeri (Carruthers), now represented by two
rhizomes, belongs to Osmunda, not to Todea or Leptopteris. This is shown : (1) By
the homogeneity of the sclerenchyma in the outer cortex around the traces and their
accompanying parenchyma which causes the sclerenchyma ring of the leaf trace to
be apparent only on the abaxial side where the trace bulges beyond the limits of the
cortex and true stem (see p. 147).

160 THE GENERIC POSITION OF OSMUNDITES DOWKERI CARRUTHERS

(2) By the form and distribution of sclerenchyma in the wing stipules of the leaf
base combined with the distribution of sclerenchyma in the continuous ring of the
emerged stipe and the arrangement of sclerenchyma in the bay of its C-shaped
xylem (cf. Hewitson 1962, Text-fig. 7A—M).

Within the genus Osmunda in the broad sense, relationship of the fossil is with the
section or sub-genus Plenasium. This is also demonstrated (1) By the sclerenchyma
distribution (again cf. Hewitson 1962, text-fig. 7A-I1). (2) By the deeply curved
C-shaped form of the leaf trace as soon as it separates from the xylem cylinder.
(3) By the presence of a pair of protoxylem strands at the inner angles of the C-shaped
traces in the inner and outer cortex. (4) By the presence of query-shaped strands in
the xylem cylinder (p. 144). (5) By the low number of leaf traces within the cortex
(p. 148).

Osmunda (Plenasium) dowkert is distinguished from any living species of Plenasium
by the greater number of xylem strands in the stem cylinder (twenty or twenty-one
approximately) and by the narrow angle at which its stipes emerge (23°).

The possible specific identity of Osmundites chandler Arnold which should also
be referred to Osmunda, sub-genus Plenasium, cannot be lightly dismissed.

The relationship of the Bournemouth and Bovey Tracey foliage of Osmunda
lignitum (Giebel) to Plenasiwm is clear (p. 158). The possibility that it may be the
foliage of the species Osmunda (Plenasium) dowkeri, known only from its rhizomes,
must be borne in mind having regard to the long range in time and space of many
members of the older Tertiary flora.

The presence of Plenasitwm in the Lower Tertiary of Western Europe, based on
independent foliar evidence supports the determination of the rhizomes as Plenasium.
The finding of this East Asiatic fern genus accords with the phytogeographical
indications provided by many Angiosperm families in older Tertiary deposits.

THE GENERIC POSITION OF OSMUNDITES DOWKERI CARRUTHERS 161

ACKNOWLEDGEMENTS

The late W. N. Edwards stimulated this research by his reluctance to use the
name Osmunda for Osmundites dowkert without a preliminary thorough investigation
as to the possibility of distinguishing the Recent genera of Osmundaceae from their
rhizomes alone. The work of Dr. W. Hewitson of Harvard has provided this
important stage in the research and he himself has supplied valuable help and com-
ment. The extraordinarily beautiful thin section prepared by the late W. N. Croft
from a newly discovered rhizome from Thanet has provided fresh information and
cleared up points left in doubt by study of the original material.

Great gratitude is due to Dr. R. E. Holttum for the interest he has taken in this
work, for obtaining Recent material from Kew and for calling attention to Dr.
Hewitson’s research as well as for various helpful suggestions. Dr. K. I. M. Chesters
has as usual typed this manuscript and she and Mr. F. M. Wonnacott have kindly
criticized while reading and editing it. The Photographic Department of the
British Museum (Natural History) deserve a special word of thanks for the trouble
they have taken in producing the excellent photographs which were not possible
with my own apparatus. Finally the Regius Professor of Botany, University of
Glasgow, has kindly lent slide K.1248 from the Kidston Collection.

REFERENCES

ARNOLD, C. A. 1952. Fossil Osmundaceae from the Eocene of Oregon. Palaeontographica,
Stuttgart, 92, B: 63-78, pls. 6-8.

CARRUTHERS, W. 1870. On the Structure of a Fern Stem from the Lower Eocene of Herne

Bay, and on its Allies, Recent and Fossil. Quart. J. Geol. Soc. Lond., 26 : 349-354, pls. 24,

25.

1872. Notes on some Fossil Plants. Geol. Mag., Lond.,9 : 49-59, pl. 2.

CHANDLER, M.E. J. 1957. The Oligocene Flora of the Bovey Tracey Lake Basin, Devonshire.
Bull. Brit. Mus. (Nat. Hist.) Geol., London, 3 : 71-123, pls. 11-17.
1961. The Lower Tertiary Flovas of Southern England, 1. Palaeocene Flovas. London
Clay Flova (Supplement). xi+354 pp., 34 pls. Brit. Mus. (Nat. Hist.), London.
GARDNER, J. S. & ETTINGSHAUSEN, C. VON 1879-82. A Monograph of the British Eocene
Flova,1: Filices. 86 pp.,13 pls. (Mon. Palaeont. Soc., London.)

HEER, O. 1862. On the Fossil Flora of Bovey Tracey. Philos. Tvans., London, 152 : 1039-
1086, pls. 55-71.

HeEwitson, W. 1962. Comparative Morphology of the Osmundaceae. Ann. Mo. bot. Gdn.,
St. Louis, 49 : 57-93, pl. I.

Kipston, R. & GyWNNE-VAuUGHAN, D. T. 1907. On the Fossil Osmundaceae, I. Tvans.
Roy. Soc. Edinb., 45 : 759-780, pls. 1-6.

Scott, R. A. 1954. Fossil Fruits and Seeds from the Eocene Clarno Formation of Oregon.
Palaeontographica, Stuttgart, 96, B : 66-97, pls. 15, 16.

SEWARD, A. C. & Forp, S. O. 1903. The Anatomy of Todea with Notes on the Geological
History and Affinities of the Osmundaceae. Tvans. Linn. Soc. Lond., 6: 237-260,
pls. 27-30.

PLATE 1

Fic. 1. Complete transverse section across rootstock showing central xylem cylinder and
limits of outer cortex of stem (dark with angular outline). It also shows the variable form of
distorted young leaf bases in surrounding mantle (contrast Kidston & Gywnne-Vaughan 1907,
pl. 4, fig. 21). 3. (slide V.29630a.)

Fic. 2 Central area of above showing dark outer cortex enclosing seven leaf traces, two
only completely immersed. A thick sclerenchyma band is seen on outer margins of five traces
which abut on edge of cortex. Inner cortex a narrow lighter region around xylem (represented
by amorphous silica) enclosing two distinct traces and a third (on left) in process of separating
from xylem. <A complete ring of sclerenchyma surrounds fully separated traces. » Io.

Bull. B.M. (N.H.) Geol. 10, 6 PLATE 1

PP AES 2

Fic. 3. Same as Pl. 1, central area with xylem cylinder and part of cortical region. Leaf
traces on margin of cortex are bounded externally by thick sclerenchyma. Separating trace
(left) has arisen from a horse-shoe trace at a slightly lower level in the rhizome. A pair of
query-shaped xylem strands are seen below (right, at 4 o’clock). Others are present in upper
hemisphere of cylinder. Two traces which have just separated from it still lie in the inner
cortex (below, and on right above). X 15. (V.29630a).

Fic. 4. Right arc of xylem cylinder in Fig. 3 showing query-shaped bundle (below and
above) in which position of protoxylem is indicated by convergence of metaxylem tracheids.
C-shaped trace in outer cortex (centre) shows one group of small protoxylem cells (inner surface
of lower limb of C). The corresponding group on the other limb is ill preserved. A newly
emerged stipe (slightly out of focus, right corner below) has two protoxylem groups discernable
by their deeper staining and greater density due to their small cavities as compared with the
metaxylem tracheids. ™X 30.

Geol. 10, 6

= Ohl

PLATE 3

Fic. 5. A trace which has just emerged from lower part of cylinder (cf. Pl. 2, fig. 3) flanked
by two roots. Lack of cell structure in inner cortex is clearly due to secondary solution of
silicified cells. Some radial distortion of xylem bundles (prior to fossilization) is seen on the
left. Pith cells visible on right. x 30. (V.29630a).

Fic. 6. The departing trace on the left (cf. Pl. 2, fig. 3). One limb is still attached to the
xylem cylinder. The other is severed except for a few tracheids. By comparing the three
preceding figures of the xylem cylinder it will be seen that there are at most twenty separate
strands (not united by any tracheid). x 30.

Bull. B.M. (N.H.) Geol. to, 6 PLATE 3

PLATE 4

Fic. 7. Hand specimen from which slide V.29630a was cut ; lower surface representing
a slightly higher level in rhizome than the slide (cf. Pl. 2, fig. 3). The departing trace on left
is here completely severed. The disrupted trace above was represented by a bulge in xylem of
slide (V.29630a). The trace (above, right) has here assumed its deep C-shaped curve. It was
still flattened and lay closely adjacent to xylem in Pl. 2, fig. 3. The trace (centre right) has now
formed its sclerenchyma ring on its outer edge as a preliminary to emerging from stem. In
these traces the slender tracheids of the protoxylem show as dense white patches on inside of
limbs of the C. Various changes in form of individual xylem strands have occurred as can
be seen on comparing with the slide (Pl. 2, fig.3). * 15. (V.29630.)

Fics. 8, 9. Show traces in surface shown in Fig. 7. The clusters of small tracheids of the

paired protoxylem strands are clear on inner angles of the C-shaped metaxylem. X 30.
(V.29630.)

PLATE 5

Fic. 10. Leaf trace still within outer cortex but about to emerge as shown by the limiting
sclerenchyma on abaxial surface (see base of Pl. 1, fig. 2). Obliquity of section and distortion
of cells causes blurring of tracheids but the pair of stained protoxylem strands show as two dark
patches on inner side of arms of C-shaped metaxylem in both figures. x 30. (slide V.29630a.)

Fic. 11. Basin-shaped upper surface of hand specimen (see p. 143). One large protuberant
horse-shoe shaped strand in white xylem ring is visible (top left). Black rings represent hollows
formed by solution of silicified sclerenchyma surrounding free stipes. The dark star-shaped
outline is due to solution of sclerenchyma which bounds the emerging edges of the traces within
cortex. xX 6:5. (V.29630.)

Fic. 12. Lower left quadrant of slide in Pl. 1, fig. 1 showing variously distorted stipes each
with its complete sclerenchyma ring flanked by sectioned wing stipules. These latter are of
loose-textured tissue strengthened by sclerenchyma strands seen in sections as black patches.
Sclerenchyma also lies adjacent to inner surface of the xylem arcs. In outer stipes the
sclerenchyma has separated into discrete patches. Small patches of scattered sclerenchyma
occur throughout the bay of the xylem arc and between the arc and the continuous sclerenchyma
ring around its stipe. oc, indicates an angle of the outer cortex otherwise cut off by upper edge
of photograph. The first two whorls of stipes outside the cortex have suffered some solution
of their silicified cells, the space formerly occupied by wing stipules now filled with amorphous
silica. 10. (V.296304.)

Fic. 13. Two wing stipules from the holotype (Kidston slide K.1248) for comparison with
Fig. 12. They show the similar arrangement of the sclerenchyma. x Io.

PLATE 6

Fic. 14. View from side of plate. Upper part of slide in Pl. 1, fig. 1 showing great width
of wing stipules which lie parallel with greatest breadth of rhizome. A stipule is clearly seen
to right of uppermost stipe in the figure. Sclerenchyma in wings and stipe as described in
Fig.12. x 10. (V.29630a.)

Bull B.M. (N.H.) Geol. to, 6

PLATE 7

Fic. 15. View from side of plate (adjacent to most abraded side of rhizome). Central
region of holotype as preserved in the hand specimen V.29629 (polished upper surface). The
strands of the xylem ring were all much distorted radially before fossilization. Cells of the
light coloured angular inner cortex are well preserved in this specimen (cf. Pl. 9, fig. 17; Pl. ro,
figs. 18-20; Pl. 12, fig. 24). There are five traces in the inner cortex, one still in close proximity
to the xylem (top centre) appearing as a low bulge. The angular outer cortex encloses thirteen
traces (only five completely immersed). x 9. (V.29629.)

PLATE

) Geol. 10, 6

Bull. B.M. (

PLATE 8

Fic. 16. View from side of plate (adjacent to more abraded side of rhizome). Centre of a
peel section showing xylem ring and surrounding tissues in best preserved region of holotype.
There are two large horse-shoe shaped strands (centre base and top left). On the centre left
of xylem ring is a departing C-shaped trace from which two roots arise at proximal end of the
arms. X15. (V.296297.) V.29629j is a better peel but for technical reasons it gave an
unsatisfactory photograph.

PLATE 8

Bull. B.M. (N.H.) Geol. 10, 6

PLATE 9

Fic. 17. View from side of plate as above. Similar region of a peel section taken slightly
higher up the rhizome than the preceeding. It therefore shows further development of xylem
strands and leaf traces. The same two large horse-shoe strands are seen. There are query-
shaped strands (especially top centre and top right), that at top centre united to form central
horse-shoe in PI. to, fig. 18, also U-shaped strands opening outwards (right at 2 o’clock and top
centre), and U-shaped strands opening inwards (left centre). Twenty-one strands of the ring
are quite unconnected. Inner cortical tissues are well preserved. Seven leaf traces are seen
in the inner cortex. Departing trace with its flanking roots is on the left but the roots are now
separated from the trace. (Contrast Pl. 8, fig. 16.) 15. (V.296290K.)

PEALE 9

.) Geol. 10, 6

Bull. B.M. (N.

PLATE to

Fic. 18. Hand specimen (abraded side of rhizome towards top right of figure cf. Pl. 8, fig. 16).
Part of xylem ring on polished lower surface of fragment V.29629a. It shows a horse-shoe
strand united to an outward opening U-shaped strand. There is another outward opening
strand on the left. The trace just departed on left is still connected at lower level of fig. 17
to form large horse-shoe at top left. A segment of the two cortexes shows C-shaped traces.
Innermost layer of free stipes with very short triangular stipules (as seen in section). X15.

Fic. 19. Separated trace in inner cortex of same surface. Paired protoxylems can be seen
by focussing in the specimen but are partly masked by reflections from polished surface in
photograph. On left (base) is U-shaped strand of xylem cylinder opening outwards. 30.

Fic. 20. Another trace on same surface (right base in Fig. 18) which has just passed into the
outer cortex. It is surrounded by an area of thin parenchyma like that of inner cortex. One
of the pair of protoxylems is visible on lower limb, inner surface. It is very clear on actual
specimen. The other is clearly indicated in the figure in corresponding position on upper limb
by elongation and convergence of metaxylem tracheids. 30.

Bull. B.M. (N.H.) Geol. 10, 6 PLATE 10

ST ae Sn

PLATE 11

Fic. 21. View from side of plate. Slide showing above the very long wing stipules on
broader side of rhizome where leaf mantle thickest. They become shorter towards the true
stem and almost non-existent in its immediate neighbourhood at base of figure. Outer cortex
cut out by edge of print at base of figure. Sclerenchyma seen in stipule wings as dark patches
in outer stipes but patches decrease in number and size passing inwards. Smallscattered patches
of sclerenchyma show inside sclerenchyma ring in some stipes. 8-5. (V.29629/.)

PLATE 11

Bull. B.M. (N.H.) Geol. 10, 6

eee

8: 1 =~ eens ¥:
a 5

PLATE 12

Fic. 22. View from side of plate.

Short wing stipules on more abraded side of rhizome,
third row of stipes outside cortex. Scattered sclerenchyma in sclerenchyma rings seen on left.
x10. (V.29629d.)

Fic. 23. Stipes on more abraded side of rhizome adjacent to outer cortex with short wing
stipules and sparse sclerenchyma.

xXIo. (Peel section, V.29629f.)
Fic. 24.

Slide showing an are of xylem with emerging root and trace on abraded side of
rhizome. X15. (V.29629d.)

Bull B.M. (N.H.) Geol. 10, 6 PLATE 12

ZQeh Wigs
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S JUL 1965

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PRINTED IN GREAT BRITAI}
BY THOMAS DE LA RUE_
COMPANY LIMITED LONDON

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FOSSIL MAMMALS OF AFRICA No. ral.
i EAST AFRICAN MIOCENE AND
i PLEISTOCENE CHALICOTHERES

_ P.M. BUTLER

BULLETIN OF

: Vol. 10 No. 7
LONDON: 1965

Ln LRN

FOSSIL MAMMALS OF AFRICA No. 18:
EAST VAFRICAN MIOCENE AND
PEEISTOCENE CHALICOTHERES

BY
PERCY M, BUTLER \

(Professor of Zoology in Royal Holloway College, University’of London)

Pp. 163-237 ; 26 Text-figures

BULLETIN OF
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FOSSIL MANIMALS OF AFRICA No. 18:
Eats AERICAN MIOCENE AND
PEEISPOCENES CHABICO THERES

Jeyulee Wil, JEUNE TK

CONTENTS
Page
INTRODUCTION . , : P : é ; LOS
Subfamily CHALICOTHERIINAE : ¢ . : : : LOG
Genus Chalicotherium Kaup . : : . : 2 . 166
C. goldfussi Kaup . : 6 . : é 6 5 OW
C. grande (de Blainville) : : ; : LOS
C. grande rhodanicum (Depéret) 6 F : : 70
C. styriacum Bach 5 : : : . : 5 7K)
Cs « : : : ; ; 0 W7O
C. wetzlert Kemalevasley 6 ‘ : 3 6 EO
C. salinum (Forster Cooper) . : 0 : : a UGA
C. brevivostvis (Colbert) : : - : : 72
C. pilgvimi (Forster Cooper) . é : : : 6 17/3}
C. vusingense sp. NOov.- . ; : . ; : 73
Subfamily SCHIZOTHERIINAE . : : F 2 PRB
Genus Ancylotherium Gaudry and related genera : F 228
Borissiakia gen. nov. . 5 : : ¢ ; . 225
Phyllotilion Pilgrim 6 C ¢ : : E225
Ancylotherium hennigi (Dietrich) : : A : 2 226
REFERENCES 6 c 2 c . c F . : . 5 Day
SYNOPSIS

The European and Asiatic species of Chalicotherium (C. goldfussi, C. gvande, C. grande rhodani-
cum, C. styriacum, Chalicotherium sp., C. wetzleri, C. salinum, C. brevirostris and C. pilgrimt)
are reviewed. A new species, Chalicotherium vusingense from the Lower Miocene cf Kavirondo
Gulf area, Kenya is described and figured in detail.

Pleistocene material from Olduvai Gorge, Tanganyika is identified with Axncylothevium
hennigi (Dietrich) and its relationship with the Lower Pliocene species A. pentelicum (Gaudry &
Lartet) from Greece and Iran is confirmed.

Ancylotherium and the related genera Phyllotillon and (Metaschizotherium) are discussed and
Phyllotillon betpakdalensis (Flerov).is made the type species of a new genus Borissiakia.

INTRODUCTION

CHALICOTHERES are known to have inhabited Eurasia from the Upper Eocene
(Eomoropus) to the Pleistocene (Nestoritherium), but in Africa only Pleistocene
forms have hitherto been described (Andrews 1923, Hopwood 1926, Dietrich 1942,
George 1950). Additional material from the Pleistocene of Olduvai Gorge,

166 EAST AFRICAN CHALICOTHERES

Tanganyika, is described in this paper ; it is identified as Ancylotherium hennigi
(Dietrich) and its relationship to A. pentelicwm from the Lower Pliocene of Greece
and Iran is confirmed.

Much more abundant material has been obtained from Rusinga, Koru and other
supposedly Lower Miocene sites in the Kavirondo Gulf area of Kenya. This
material represents a new species, Chalicotherium rusingense, a primitive relation of
the well-known C. (=Macrotherium) grande of the Upper Miocene of Europe. The
same species occurs at Napak, Uganda (Butler 1962).

The main centre of chalicotherian evolution appears to have been in Asia. By
Oligocene times two main branches of the family had differentiated: the
Schizotheriinae and the Chalicotheriinae. Though members of both branches
invaded Africa, this continent seems to have formed an evolutionary backwater,
for both the known African genera occurred in Europe at earlier dates :
Chalicotherium in the Upper Oligocene and Ancylothervum in the Lower Pliocene.

Most of the material described is the property of the National Museum of Kenya,
Nairobi, and I wish to express my best thanks to Dr. L. S. B. Leakey for permission
to study it. Acknowledgement is also due to Dr. E. I. White, F.R.S., for access to
African chalicotherian material in the British Museum (Natural History), and to
Dr. W. W. Bishop for the loan of specimens that he collected at Napak. Extensive
use was made for comparative purposes of the important collections of chalicotherian
material in the British Museum and in the Muséum d’Histoire Naturelle in Paris,
and I am greatly indebted to the staff of these museums for much valued assistance,
particularly to Father R. Lavocat and to Dr. A. J. Sutcliffe. I also wish to acknow-
ledge the kindness of Prof. J. Viret and Prof. E. Kuhn-Schneider in sending casts of
specimens, and of Prof. H. Tobien and Prof. S. Schaub in giving valuable advice.

Subfamily CHALICOTHERIINAE
Genus CHALICOTHERIUM Kaup, 1833
Review of European and Asiatic Species

The type species of Chalicotherium is C. goldfussi Kaup (1833) from the Pontian
of Europe, ranging from Spain through Germany to Greece. This replaces the
Upper Miocene species usually known as Macrotherium grande (de Blainville 1849),
which was based on material from Sansan (Vindobonian). There is little doubt
that M. grande is directly ancestral to C. goldfussi and the late Vindobonian M.
grande rhodanicum Depéret (1892) and the Nikolsburg (Sarmatian) material
described by Abel (1922) are transitional. A generic distinction between Macro-
therium and Chalicotherium is therefore not justified, and Macrotheriwm must fall
into synonymy (von Koenigswald 1932). The ancestor of C. grande is probably
C. wetzleri Kowalewsky (1874) from the Aquitanian. No specimens of Chalico-
therium have been recorded from European strata of undoubted Burdigalian age.

C. salinum (Forster Cooper) from the Chinji and Nagri formations of the Siwaliks
(probably late Miocene to early Pliocene, Thenius 1959) is closely related to C. grande.
However, C. brevirostris (Colbert 1934) from the Upper Miocene of Mongolia is quite

EAST AFRICAN CHALICOTHERES 167

distinct from the European species, and may be the ancestor of the Pleistocene
genus Nestoritherium. The only other Asiatic species, C. pilgrimu (Forster Cooper),
is a very primitive form resembling Schizotheriwm. Von Koenigswald (1932)
included Schizotherium turgaicum Borissiak in the genus Chalicotheriwm, but
additional information on its structure (Borissiak 1946, Belyaeva 1954) has confirmed
its relationship to Schizotherium priscum. Moropus matthew: Holland & Peterson
and M. merriami Holland & Peterson were also transferred to Chalicotherium by
von Koenigswald following a suggestion by Matthew (1929), but on what appear
to me to be insufficient grounds.

Chalicotherium goldfussi Kaup
Text-figs. IE, 5H, 13

1823 Pangolin gigantesque, Cuvier, p. 193, pl. 16, figs. 26, 27.

1832 Manis gigantea Cuvier ; Kaup & Scholl, p. 7.

1832 Lophiodon Goldfussi Kaup & Scholl, p. to (Nomen nudum?)

1833 Chalicotherium goldfussi Kaup, pp. 4-6, pl. 7, figs. 3-5.

1833 Chalicotherium antiquum Kaup, pp. 6, 7, pl. 7, figs. 6, 7.

1844 Macrotherium giganteum Pictet, p. 232, pl. 8, fig. 5.

1849 Chalicotherium goldfussi Kaup ; de Blainville, p. 82, pl. 8.

1849 Chalicotherium antiquum Kaup ; de Blainville, p. 83, pl. 8.

1859 Chalicotherium goldfussi Kaup ; Kaup, p. 1, pl. 1, figs. 1-3, 5.

1859 Chalicotherium antiquum Kaup ; Kaup, p. 1, pl. I, figs. 4, 7.

1885 Chalicotherium baltavarensis Petho, p. 69.

1886 Chalicotherium goldfussi Kaup ; Lydekker, p. 162 (in part).

1891 Chalicotherium antiquum Kaup ; Schlosser, p. 87.

1920 Chalicotherium Goldfussi Kaup ; Abel, p. 30, text-figs. 3, 5, 7.

1922 Chalicotherium goldfussi Kaup ; Abel, p. 118, text-figs. 108-111.

1927 Chalicotherium goldfussi Kaup ; Barnes, p. 22, text-fig. 7.

1929 Chalicotherium cf. goldfussi Kaup ; Arambourg & Piveteau, p. 23, pl. 3, figs. 1-3.
1929 Chalicothervium goldfussi Kaup ; Matthew, p. 518.

1932 Chalicotherium goldfussi Kaup ; von Koenigswald, p. 14, pl. 1, figs. 9, 10 ; pl. 3, fig. 37.
1937 (?) Ancylopoda gen. et sp. indet., Bohlin, p. 104, pl. 9, figs. 7-9.

1939 Chalicothevium goldfussi Kaup ; Webrli, p. 26, pls. 1, 2.

1943 Chalicothervium goldfussi Kaup ; Villalta & Crusafont, p. 153, text-fig. 24, pl. 9, figs. 3-5.
1949 Chalicotherium goldfussi Kaup ; Zapfe, p. 69, text-figs. 1-3.

The type material is Pontian, but the palate and cervical vertebra described by
Abel (1922) from Nikolsburg are probably Sarmatian (Thenius 1959). A metacarpal
II (M.11349) and an astragalus (M.11351) (Text-fig. 13) from Pikermi, now in the
British Museum (Natural History), belong to Chalicotherium and may be referred
to this species. A phalanx from Tsaidam, China, described by Bohlin (1937) may
also belong to this species.

Wehrli (1939) has redescribed the teeth and phalanges from the type locality
(Eppelsheim). The molars are larger and proportionately broader than in the type
material of C. grande from Sansan, but are not so clearly distinguishable from
C. grande rhodanicum. The protocone is usually isolated from the protoconule
(Matthew 1929), the Nikolsburg specimen being intermediate in this respect. The
premolars are more reduced, and P, is absent in a specimen from Salonica

168 EAST AFRICAN CHALICOTHERES

(Arambourg & Piveteau 1929). P,P, are figured by Barnes (1927) ; the two
associated teeth identified by Wehrli (1939) as P, and P, are probably P, and M,
respectively. In the juvenile skull from Salonica the unerupted P? and P* show a
partial division of the deuterocone into protocone and hypocone, as in some
specimens of Moropus (Osborn 1890).

C. baltavarensis is based on a mandibular fragment containing a molariform tooth.
A cast of this specimen is in the British Museum (Natural History). The tooth
is fully molariform and therefore unlikely to be a premolar. It is too small (length
25 mm.) for a molar of C. goldfussi. The lack of a metastylid excludes Ancylotherium
pentelicum, to which Schlosser (1891) referred it. It is tentatively identified as Pd,
of C. goldfussi. Anteriorly there are alveoli for Pd, and Pd,, and then a short
diastema (20-25 mm.). According to Peth6d (1885), there is a trace of a canine
alveolus at the anterior end of the specimen.

The metacarpal from Pikermi is very much like specimens of C. grande. The
astragalus from Pikermi is relatively lower than in C. grande, and has a more extensive
contact with the cuboid. Metatarsal III (Zapfe 1949) 1s broader than in C. grande.
Basal phalanges described by Wehrli (1939) and by Villalta & Crusafont (1943) are
larger than in typical C. grande. Wehrli’s fig. 26 shows a phalanx from the manus
and fig. 25 one from the pes ; in the manus the metacarpal facet occupies a greater
proportion of the dorsal surface than in C. grande.

Macrotherium giganteum Pictet was based upon a combination of the ungual
phalanx from Eppelsheim described by Cuvier (=C. goldfusst) and Lartet’s material
from Sansan (=C. grande). The specific name giganteum has priority over grande,
and in order to avoid changing a well known name I here select the ungual phalanx

as the lectotype of Pictet’s species, which thus becomes synonymous with
C. goldfussi.

Chalicotherium grande (de Blainville)
Text-figs. ID, 4C, D, 5G, 8C, IOG-L, IIF-J, I12F-J, 13-15, 16E, 17D

1837 Anoplotherium Lartet, p. 88.

1837a Macrotherium Lartet, p. 424.

1839 6Anoplotherium magnum Lartet, p. 26. Nomen nudum.

1844 Macrotherium giganteum Pictet, pp. 232, 233 (in part). See also discussion of C. goldfusst
above.

1848 Anisodon (Choelichotherium) Pomel, p. 686.

1849 Anoplotherium grande ‘ Lartet’ ; de Blainville, p. 66, pls. 3, 8.

1849 Chalicotherium anisodon de Blainville, pp. 68, 152, pl. 9.

1850 Chalicothervium grande (de Blainville) Gervais, p. 91.

1850 Macrotherium giganteum ‘ Lartet’ ; Gervais, p. 135, pl. 43.

1851 Macrotherium sansaniense Lartet, p. 22.

1851 Anisodon magnum Lartet, p. 30. (The name Anisodon first appears in the MS catalogue
of Lartet’s collection (dated 1847). This is the ‘‘ Cat. Man.’ referred to by Lartet (1851).
It is preserved in the Paris Museum).

1853 Chalicotherium grande ‘ Gervais’ ; Pictet, p. 337, pl. 15, fig. 6.

1855 Macrothevium Lartet ; de Blainville, p. 37, explanation of unnumbered plate.

1859 Anisodon larteti Kaup, pl. 2, figs. 1-5 (=Chalicotherium antiquum, in part).

1847 Chalicotherium (Anisodon) ; Kowalewsky, p. 175, pl. 8, figs. 73, 74.

EAST AFRICAN CHALICOTHERES 169

1877 Macrotherium giganteum ‘ Lartet’ ; Gervais, p. 226, pl. 2, figs. 2-5.

1886 Chalicotherium goldfussi Kaup ; Lydekker, p. 161 (in part).

1891 Chalicotherium magnum (Lartet) Filhol, p. 294, pls. 43-46.

1892 Macrotherium grande ‘ Lartet’ ; Depéret, p. 61.

1893 Macrotherium giganteum ‘Lartet’ ; Osborn, p. 121, text-fig. 3.

1898 Macrotherium grande ‘ Lartet’ ; Roger, p. 29, pl. 3, fig. 7.

1902 Chalicotherium anisodon de Blainville ; Schlosser, p. 212. (States the name has priority
but rejects because of non-usage).

1913 Macrotherium grande ‘ Lartet’ ; Holland & Peterson, pp. 209, 217, text-figs. 4, 15, 98.

1913 Macrotherium grande ‘ Lartet’ ; Wegner, p. 246, pl. 14, figs. 27-30.

1920 Macrotherium magnum Lartet ; Abel, p. 50, text-figs. 11, 13, 14.

1922 Macrotherium magnum Lartet ; Abel, p. 197, text-fig. 1624, B.

1923 (?) Macrotherium oggenhausense Dietrich, p. 190, text-fig. 1. (See Schlosser 1926).

1925 Macrotherium grande ‘ Lartet’ ; Stehlin, p. 139, text-fig. 18a, b.

1928 Macrotherium grande ‘ Lartet’ ; Dietrich, p. 367.

1932 Chalicotherium grande ‘( Lartet )’ ; von Koenigswald, pp. Io, 13, pl. 1, figs. 8, 9, 14-17 ;
pl. 2, fig. 22 ; pl. 3, figs. 30-36.

1935 Macrotherium sansaniense Lartet ; Boule & Piveteau, p. 637, text-figs 1026, 1029.

1936 Macrotherium magnum Lartet ; Bohlin, p. 323.

1943 Macrotherium grande ‘ Lartet’ ; Villalta & Crusafont, p. 125, text-figs. 1-23, pls. I-9.

1949 Chalicotherium grande ‘( Lartet )’ ; Zapfe, p. 69, text-figs. 1-3.

1949a Chalicotherium grande ‘( Lartet )’ ; Zapfe, p. 176.

1958 Chalicotherium grande ‘( Lartet )’ ; Mottl, p. 46.

1964 Chalicotherium grande de Blainville ; Ginsberg, p. IT.

The erroneous ascription of the name gvande to Lartet began with de Blainville
(1849). In 1837 Lartet did not use a specific name but merely referred to “ un grand
Anoplotherium ”’ ; in 1839 he used the name magnum for the same material (without
description).

Chalicotherium grande is characteristic of the Vindobonian of Europe. Details
of its anatomy have been described in many papers, of which the more important
are as follows : de Blainville (1849) figured teeth, skull and mandible, and also
(1855) limb-bones and vertebrae. Lartet (1851) described the skeletal remains from
Sansan. Gervais (1850) re-figured the limb-bones and also figured an atlas vertebra.
Gaudry (1862) gave various details of the limb-bones which he compared with
Ancylotherium. Kowalewsky (1874) figured some teeth. Gervais (1877) discussed
and figured the feet. Fuilhol (1891) gave an account of his discovery of a fairly
complete skeleton including a skull, unfortunately badly crushed ; he described
various details of the skull figured by de Blainville and figured some mandibles, one
of them containing milk dentition. Wegner (1913) described some teeth and an
astragalus. Holland & Peterson (1913) gave a new restoration of the manus,
figured the astragalus, and compared the various bones in some detail with those of
Moropus. Abel (1920) compared C. grande (‘‘ Macrotherium’’) with Ancylotherium
(“ Chalicotherium”) ; his conclusions were criticised by Dietrich (1928). Von
Koenigswald (1932) compared C. grande with Metaschizotherium and figured a molar
and some phalanges. Villalta & Crusafont (1943) described teeth and limb-bones,
including a number from a single individual. Zapfe (1949) figured a third metatarsal
which he compared with C. goldfussi.

170 EAST AFRICAN CHALICOTHERES

The specimen from Sansan figured by de Blainville as C. anisodon and by Filhol
as C. magnum var. secundarium is pathological. P, is separated from P, and lies
in the diastema, considerably tilted forwards in the jaw. There exists in Paris
another half-mandible with normal premolar alveoli, which appears to belong to the
opposite side of the same individual.

Chalicotherium grande rhodanicum (Depéret)

1887 Chalicotherium aff. modicum Depéret, p. 228, pl. 13, fig. 35.
1892 Macrotherium grande var. rhodanicum Depeéret, p. 63, pl. 2, fig. 1, pls. 3, 4.

Specimens from La Grive St. Alban are larger and more progressive than typical
specimens of C. grande from Sansan, and are distinguished as the subspecies
rhodanicum.

C. grande rhodamicum is known from an incomplete skull and mandible, together
with metacarpals and phalanges (Depéret 1892). Isolated molariform teeth
compared by Depéret (1887) with C. modicum (=Schizotherium priscum) are
probably milk molars of C. grande rhodanicum. Depéret’s statement that metacarpal
II has almost no contact with the trapezoid is not borne out by his figure.

Chalicotherium styriacum Bach
Text-fig. 4E
1913 Chalicotherium styriacum Bach, p. 688, pl. 28, fig. ra, b.

This species is based on a mandible from Eggersdorf (probably of Pontian age),
a cast of which is in the British Museum (Natural History). It is rather small,
considering its late date : the molars fall into the size range of C. grande from
Sansan. The metastylid is more distinct than in any known specimen of C. grande,
and, so far as can be judged from the worn teeth, the entoconid of P, is absent.

Chalicotherium sp.
1913 Chalicotherium sp., Bach, p. 687, pl. 28, figs. 2-4.

Bach (1913) described some mandible fragments and an incomplete upper moiar
from Voitsberg, regarded as Middle Miocene by Pia & Sickenberg (1934). They
appear to represent a smaller form than C. grande. The total length of the lower
molars is 82 mm., whereas in specimens of C. grande from Sansan this measurement
ranges from go to 105 mm. In an unworn molar there is a small but distinct
metastylid.

Chalicotherium wetzleri Kowalewsky
Text-fig. 8B

1837 Palaeotherium schinzii Meyer, p. 676. (Nomen nudum).
1847 Chalicotherium wetzleri Kowalewsky, p. 248, pl. 8.
1883 Chalicotherium modicum Gaudry ; Schlosser, p. 165.

EAST AFRICAN CHALICOTHERES 171

1891 Chalicotherium wetzleyri Kowalewsky ; Schlosser, p. 87.

1914 Chalicotherium wetzleyri Kowalewsky ; Stehlin, p. 187.

1929 ©Macrotherium wetzleri (Kowalewsky) Viret, p. 267.

1932 Schizotherium wetzlevri (Kowalewsky) von Koenigswald, p. 16, pl. 1, fig. 7.

Palaeotherium schinzii was based on a mandible from Bollingen, now in Ziirich.
I am greatly indebted to Prof. Tobien for his help in finding this specimen, and to
Prof. Kuhn-Schneider for sending me a cast (Text-fig. 8B). The identity of
P. schinzu with C. wetzleri was suggested by Schlosser (1891) and accepted by
Stehlin (1914). The name Amisodon schinzii mentioned by Schlosser does not appear
to have been published previously, and may have been a manuscript name. The
original description is very brief: “‘um ein Viertel kleiner als Palaeotherium
magnum und ungefahr eben so viel grdsser als Palaeotherium crassum”’. Prof.
Schaub kindly informs me that it was Stehlin’s opinion that this poor characteris-
ation could not validate the name schinzi1, taking into account the great diversity of
Palaeotherium species. Rather than revive a name that has been unused for well
over a century it seems wise to accept this opinion.

C. wetzlert is Aquitanian in age, and might be expected to be more primitive than
C. grande. Nevertheless the size difference is slight. The total molar length is
92 mm. on the Bollingen mandible, and slightly more in a specimen measured by
von Koenigswald (1932), and the molars therefore fall within the lower part of the
size range of C. grande from Sansan. The premolar/molar index is rather high (54),
but still within the range of C. grande (47-55). Mz is similar to M,, a clear distinc-
tion from Schizotheriwm, where M; has an enlarged hypoconulid. The main
difference from C. grande is the presence of a distinct metastylid, a primitive character
found also in Schizotherium. Pd* and Pd? also resemble Schizotherium in the
completeness of the protoloph. The Bollingen mandible differs from C. grande in
that the step in the upper border anterior to P, is a little more pronounced. The
diastema seems to have been at least as long as in C. grande, but the anterior end of
the jaw is not preserved. A juvenile mandible from St. Gérand-le-Puy described
by Filhol (1879) belongs not to C. wetzleri, as Viret (1949) suggested, but to
Phyllotillon.

Viret (1929) referred to C. wetzleri two basal phalanges, one apparently from the
manus, the other from the pes. They are much smaller in proportion to the teeth
than in C. grande, and reference is somewhat doubtful. They might belong to an
unknown smaller species, or to Phyllotillon.

Whether Chalicotheritum was present in the Stampian is still uncertain. According
to Filhol (1877), chalicotherian material from the Phosphorites of Quercy is not
homogeneous, and primitive species of Chalicotherium might have been confused
with Schizotherium priscum.

Chalicotherium salinum (Forster Cooper)
1876 (2?) Manis sindiensis Lydekker, p. 64, pl. 8, figs. 11-14.
1922 Macrotherium salinum Forster Cooper, p. 542, text-figs. 1-3.
1929 Macrotherium salinum Forster Cooper, ; Matthew, p. 517.
1932 Chalicotherium salinum (Forster Cooper) von Koenigswald, p. 22.
1935 Macrotherium salinum Forster Cooper ; Colbert, p. 167, text-figs. 72-76.

172 EAST AFRICAN CHALICOTHERES

This species is known from the Chinji and Nagri (late Miocene—early Pliocene)
formations of the Siwaliks. It is based on an isolated M? ; additional material was
described by Colbert (1935). It averages rather smaller than C. grande. In the
upper molars the protoloph is complete, and there is a sharp ridge on the buccal
slope of the paracone. A basal phalanx of the manus is proportionately a little
narrower than in C. grande. In two middle phalanges there is a very prominent
volar process at the proximal end, uncommon in C. grande but present in the phalanx
that constitutes the holotype of Manis sindiense. In other respects C. salinum
appears to agree closely with C. grande, and the two species are undoubtedly closely
related.

Chalicotherium brevirostris (Colbert)

1934 Macrotherium brevivostris Colbert, p. 374, text-figs. 11, 12, 134, c, e, g (?d, f), 14% (2h, /).
1934 Macrotherium sp., Colbert, p. 381, text-figs. 14h, k—o.

This species is known only from the Tung Gur formation (Upper Miocene) of
Mongolia. The upper molars agree in size and proportions with those of C. grande,
but the premolars are more reduced, as in C. goldfussi. In the holotype the
protoloph of the molars is complete, as in C. salinum. The skull differs from that of
C. grande in several respects, detailed by Colbert (1934). Upper canines are absent.
The lower jaw and teeth are unknown.

The only postcranial bones known are a metatarsal IV and some phalanges. The
metatarsal is rather small and may belong to a smaller individual than the skull.
The width and thickness of its shaft bear the same proportion to the length of the
bone as in C. grande, but the dorsovolar diameters of the proximal and distal ends
are proportionately greater ; in lateral view the ends of the bone project beyond the
dorsal surface of the shaft, whereas in C. grande the dorsal surface of the metatarsal
is nearly flat. A basal phalanx, probably from digit II of the pes (Colbert 1934
fig. 13c) agrees well in size and proportions with specimens of C. grande. Two other
basal phalanges may reasonably be referred to C. brevivostris, though Colbert believed
that they belonged to a larger species. One (fig. 14/) agrees well in size with
phalanges of C. grande from digit III of the manus, though it is rather more parallel-
sided and less broadened proximally than in most specimens of that species. It is
not very different, however, from a phalanx from Spain figured by Villalta &
Crusafont (1943). In shape it also resembles a phalanx of C. salinuwm, which is
smaller in size. A phalanx probably from digit IV of the pes (fig. 14h) is a little
larger than in C. grande ; its metatarsal articulation occupies a somewhat
smaller proportion of the dorsal length than in that species. Five of the six middle
phalanges figured by Colbert, though differing greatly in size, can be matched with
specimens of C. grande, and there is no reason why they should not be referred to
C. brevivostris. The aberrant specimen (fig. 13d), which has a more dorsally
facing proximal articulation, might belong to one of the Schizotheriinae. This may
also be true of the ungual phalanges, which are much lower in proportion to their
length than in C. grande. One of them (fig. 13 /) is also very broad, with a wide
cleft, resembling a specimen of Schizotherium turgaicum figured by Belyaeva (1954).

EAST AFRICAN CHALICOTHERES 173

Chalicotherium pilgrimi (Forster Cooper)
Text-figs. IB, 4A, 14
1910 ©Schizotherium sp. ind., Pilgrim, p. 67.
tg1i2 Schizotherium sp. ind., Pilgrim, p. 36.
1920 6 Schizotherium pilgvimi Forster Cooper, p. 362.
1929 ©Schizotherium pilgvimi Forster Cooper ; Matthew, p. 518.
1932 Chalicotherium pilgvimi (Forster Cooper) von Koenigswald, p. 22.
1935 Schizotherium pilgyimi Forster Cooper ; Colbert, p. 162.

This species, from the Bugti Beds (Lower Miocene) of Baluchistan, resembles
Schizotherium priscum in its relatively small size, and also in most features of the
upper molar pattern, for example the relatively buccal position of the ectoloph
(Text-fig. 1B). However, the length/width index of M? is 106, which is lower than
in S. priscum (110-115) but falls within the range of C. grande (104-111). Thereisa
well-developed metastylid on M, and Pd,, present in Schizotherium but also in
C. wetzlert.

Although Forster-Cooper did not refer any postcranial material to this species,
he described from the same beds a metatarsal II (Text-fig. 14) and two basal
phalanges which are undoubtedly chalicotheriine and probably belong to C. pilgrimz.
The only other chalicothere so far recognised from the beds is Phyllotillon naricus
Pilgrim, a schizotheriine which could not be the possessor of the bones in question ;
moreover, phalanges referable to this species occur. If the metatarsal and
phalanges are correctly referred to C. pilgrim, it would be necessary to follow von
Koenigswald (1932) in removing the species from Schizotherium, in spite of the reten-
tion of primitive characters in the teeth.

Chalicotherium rusingense sp. nov.
Text-figs. I-20

Diacnosis. A small species of Chalicotherium with teeth similar in size to those
of C. pilgrim and Schizotherium priscum ; resembling these in the presence of a
metastylid on the lower molars (except in a few individuals), but differing from them
in that the paracone and metacone are situated about half-way across the crown.
Canines present in both jaws ; incisors °/,. Snout relatively elongated ; diastema
proportionately longer than in C. grande. Astragalus less depressed than in C.
grande. Basal phalanges of the manus more elongated than in C. grande, especially
in digit III.

HoLotyre. B.M.N.H., no. M.25270. A left maxilla with upper dentition, from
site R107, Rusinga Is.

DISTRIBUTION. Lower Miocene (?) beds of Kenya (Rusinga, Karumbu, Mfwan-
gano, Songhor, Koru) and Uganda (Napak).

DESCRIPTION.

Upper molars. (Text-figs. IC, 2, 3A.)
Associated upper molars are present in six specimens: all three molars are

174 EAST AFRICAN CHALICOTHERES

preserved in the holotype, though fairly heavily worn ; in R137.49* M! is well
preserved, and M? and M® are badly broken ; R483.51 and R1382.51 contain M!
and M? in association ; Mz4203 and an un-numbered specimen from site R31
contain M? and M%. In addition there are 14 fairly complete isolated molars and a
number of fragments.

The following measurements were made wherever possible:—(1) the greatest
anteroposterior length, (2) the transverse width perpendicular to (1), (3) the anterior
oblique width across the parastyle and protocone, (4) the posterior oblique width
across the mesostyle and hypocone. (Tables I and II). When the results were
plotted on probability paper (Harding 1949) it was found that the specimens did
not form a unimodal population : five specimens, containing 7 molars, formed a
secondary grouping near the upper limit of the range of variation. It is therefore
possible to distinguish a large form from the typical form of the species. The
following specimens are referred to the large form :—

R483.51 (M!, M?) from Kiahera, Rusinga.

R411.48 (M!) from the top of Kiahera Hill, Rusinga.
M14202 (M3) from Koru.

R1382.51 (M?, M?) from Hiwegi, Rusinga.

R533.51 (M$) from Kamasengere, Rusinga.

The first three of these sites have also yielded upper molars of the typical form so
that the difference cannot be due to geological age. The disproportion in numbers
(29 teeth of the typical form : 7 of the large form) disfavours a sexual difference.
It is possible that two closely related species were present, differing in their ecology :
the large form may have occupied a habitat where it was less liable to fossilisation.
However, as morphological distinctions between the two forms are very slight, and
wide variations in size are known in other chalicotheres, such as Phyllotillon
betpakdalensis (Borissiak 1946), it is not proposed at present to give the large form a
distinct specific name.

M* is much the smallest of the three molars. Its length usually slightly exceeds
the transverse width, but the length/width index ranges from 93 to 107. The
apparent length is frequently reduced by wear of the metastyle and flaking away of
the enamel on the anterior border.

The outline of the base of the tooth might be described as a quadrilateral with
rounded apices. There is a bay, varying in depth, somewhat anterior to the middle
of the buccal side. The posterior side is convex, reaching its greatest prominence
near the mid-point. The anterior side is also convex, but it recedes lingually, so
that the lingual side is much shorter than the buccal side. There is a slight bay in
the lingual side, situated more posteriorly than the buccal bay. The anterior
oblique width is approximately equal to the posterior oblique width (index,
anterior/posterior width, 97-108).

*Specimen numbers beginning R, Sgr or MF W are field numbers indicating locality (Rusinga, Songhor
or Mfwangano respectively) and year of collection. These specimens are the property of the National
Museum of Kenya, Nairobi. Registration numbers of National Museum of Kenya, Nairobi specimens
begin with F, those of the British Museum (Natural History) with M.

EAST AFRICAN CHALICOTHERES 175

Fic. 1. Upper cheek teeth. a. Schizotherium priscum, from specimens in the Paris
Museum. B. Chalicotherium pilgrimi, M1 and M2, BMNH. Mi2166. c. C. rusingense,
holotype. oD. C. grande, P4—M3, from cast, BMNH. Mqo821. E. C. goldfussi, from cast
of Nikolsburg specimen, BMNH. Mi2154. All x #.

There are three roots. The buccal roots correspond to the two lobes of the
buccal outline ; in cross-section they are oval, with their long axes transverse to the
tooth. The lingual root is extended in an anteroposterior direction, and is partly
divided by grooves on its buccal and lingual surfaces into anterior and posterior
moieties, corresponding to the lobes of the lingual outline. The buccal roots taper
apically ; their nearly perpendicular buccal surfaces are situated near the surface
of the maxilla. In four specimens in which M1? is implanted in the bone their length
ranges from 16-3 to 20 mm., the anterior root being apparently slightly longer than
the posterior. The lingual root is more frequently preserved in isolated teeth, in

176 EAST APRICAN CHALICOTHERES

which its length is 11-3-14-5 mm. It is stouter than the buccal roots and less
tapering. It is inclined lingually, diverging from the buccal roots. The base of the
tooth between the roots is flat, and in well-preserved specimens it is crossed by three
inter-radicular crests which arise from the inner sides of the roots and meet in the
centre of the base.

TABLE I.

Measurements (mm.) of teeth of Chalicotherium rusingense, holotype.

Length Transverse Oblique width
Anterior Posterior
M3 260°3 25°0 27:0 23-11
M? 27:6 25'0 24:6 24°8
M1 20°5 19°3 19:0 19°'5
IP 13°0 17°8
IP 12°3 14°2
2 10:0 0:5

The crown is dominated by the W-shaped ectoloph, formed from the paracone
and metacone. These cusps are approximately equal in height. Their tips are
placed near the mid-line of the crown, their lingual surfaces are nearly vertical, and
their buccal surfaces are inclined at about 40° to the plane of the base of the tooth.
Both cusps are V-shaped in crown view, but the arms of the metacone are much
more divergent than those of the paracone, as the posterior arm runs directly back-
wards (on little-worn teeth) to the mid-posterior prominence of the outline. A
ridge runs down the buccal slope of the paracone, and a similar but fainter and
shorter ridge is sometimes present near the tip of the metacone. The ectoloph is
buttressed by the parastyle and mesostyle, which are situated on the two lobes of the
buccal margin, and are almost as high as the paracone and metacone. Unworn
specimens of M? and M® show that the tips of the parastyle and mesostyle do not lie
in the ectoloph, but are joined to it by transverse crests ; this is probably also true
of M!, but sufficiently unworn specimens of this tooth are unknown. Seen from the
buccal side, the mesostyle (and presumably also the parastyle, which has suffered
damage on all the specimens of M1) thickens towards the base. In two of the three
specimens of M! referred to the large form a swelling is present about half-way up
the anterobuccal face of the mesostyle ; it is not present in the typical form. The
buccal cingulum is very indistinct, least so externally to the metacone ; where it
joins the posterior crest of the metacone a rudimentary metastyle is formed.

The ectoloph wears on its lingual surface and so becomes displaced towards the
buccal side of the crown in worn specimens. The posterior crest of the metacone
becomes rotated buccally and the angle between the arms of the metacone V is thus
reduced. Tongues of exposed dentine extend to the tips of the parastyle and
mesostyle, so that in very worn teeth the styles are hardly distinguishable from the
ectoloph itself.

The protoloph and metaloph branch off from the anterior arms of the paracone
and metacone respectively, and run obliquely backwards, parallel to the anterior

EAST AFRICAN CHALICOTHERES 177

border of the tooth. Their anterior surfaces are nearly vertical, their posterior
surfaces much less so. The protoloph is short, extending only to the protoconule
which is placed close to the lingual side of the paracone. The protocone is situated
above the anterior lobe of the lingual margin, and more posteriorly than the
protoconule, from which it is separated by a valley. The protocone is subequal in
height to the protoconule, and much lower than the paracone. It has the form of a
cone, tilted lingually so that its lingual surface is nearly vertical, and developed into
a ridge anteriorly. In four specimens a low but distinct crest arises on the lingual
side of the protoconule, crosses the intervening valley and joins the anterior ridge
of the protocone ; the crest is absent in five other specimens. The metaloph rises
at its lingual end to form the hypocone, which is somewhat higher than the protocone
and placed a little less lingually on the crown. There is no trace of a metaconule.

The anterior border of the crown is occupied by a broad cingulum, its edge formed
by a sharp marginal crest which branches off from the ectoloph lingually to the
parastyle. This crest rises in front of the protoconule ; farther lingually it falls
rapidly and merges into the anterolingual side of the protocone. There is no distinct
cingulum lingually to the protocone. A posterior marginal crest arises from the
tip of the hypocone, enclosing with the metaloph and metacone a triangular basin
(postfossette). In seven out of ten specimens this basin is interrupted by a small
transverse crest that branches off the lingual side of the ectoloph. Owing to wear,
details of the central basin cannot be determined.

TABLE II.

Dimensions of upper molars, C. rusingense.

Typical form Large form
P (t-test)
N m s Range (mm.) | Measurements (mm.)

Length Mt? 7 19:7 0-78 19:0-20°8 PWG, PPG <I OW
M? 7 a2) Om RA A 27720 28:9, 2973 <-02

M$ 5 24:9 0:98 24:0-26:3 26:2, 20°5 0H
Transverse Mt? 9 1971 0:82 18:0-20:3 PUM, PRO, LRA <-O1
width M? IO 24°7 0:92 23:0—26'5 28°5 <-‘o1
M$ 6 24:0 1:02 23°3-25:2 DIO), Bij <-02
Oblique width M? 7 19:7 O61 18:8-2073 22'5, 23:0 <-O1
(parastyle- MM? 6 25°38 1:04 24:6-27:2 30°8, 31:0 <-o1
protocone) M3? 5 26:2 0°57 25:6-27:0 28-6, 3073 <-O1
Oblique width M? 9 19° £o81 18-4-20°9 214s 2i-Q, 22°5 < ‘ol
(mesostyle- M? IO 23°9 I:00 22:1-25:2 27°5 <-o1
hypocone) M3 So 2270 0-01 20-60-2351 23°8 <+05

The last column gives the probability (obtained by a t-test) that the means of the large form
fall within the range of variation of the typical form.

178 EAST AFRICAN CHALICOTHERES

M?is about 30% larger than M‘in all dimensions. The posterior lobe of the lingual
edge is less developed, the lingual bay being situated relatively more posteriorly.
In correlation with this, the posterior moiety of the lingual root is proportionately
smaller, and the hypocone, though not reduced in height, occupies a smaller
proportion of the lingual border of the crown. The metacone is lower than the
paracone when unworn, and it occupies a smaller proportion of the ectoloph. The
index, anterior oblique width/posterior oblique width ranges from Ior to 113.

The variations observed in M! are also present in M*. The bay in the buccal
outline varies in depth. The swelling on the anterobuccal face of the mesostyle
occurs in the only specimen of the large form in which this region is preserved, but it
also occurs in a specimen of the typical form (R689.49) ; it is absent in four other
specimens. The crest joining the protoconule to the protocone is present in seven
specimens (including one of the large form) and absent in three (one of the large
form) ; it is particularly strongly developed in M14203 (the smallest specimen).
The small transverse crest in the postfossette is present in six specimens and absent
in four. In R689.49 the buccal roots are kidney-shaped in cross-section, owing to a
groove on the internal side of each root ; this variation does not occur in six other
specimens, and it was not observed in M!.

Five specimens of M? are practically unworn, revealing details of the central
basin that could not be seen on M!. Between the protocone and the hypocone is a
flattened area demarcated lingually by a marginal ridge. A small crest (crista)
passes backwards from the paracone down the lingual side of the ectoloph to the
deepest part of the central basin ; it is visible in all five specimens. In M 14203
another crest (crochet) passes down the anterior face of the metaloph to end in the
central valley opposite the base of the crista. A trace of this is present in R 929.50,
which is more worn, but it is absent in four unworn specimens. A trace of the crochet
appears to be present in two specimens of M! (R 496.50 and R 12.48).

M? is very nearly of the same length, width and height as M?. It differs however
in proportions. The posterior part of the crown is shorter in proportion to the
anterior part, and also narrower (anterior/posterior oblique width index 115-121).
The posterior buccal root is displaced lingually in relation to the anterior buccal
root. The anterior of the two buccal roots is slightly longer than the posterior
(visible in two specimens), which is of about the same length as the lingual root.
The lobe of the outline that bears the hypocone is less prominent than on M?, and the
bay in the lingual border is very slight, though the partial subdivision of the lingual
root resembles that of M?. The protocone is placed relatively farther back on the
crown, and the hypocone is a little nearer to the posterior edge and less lingual than
in M*. The metacone is much lower than the paracone and slightly lower than the
mesostyle. It is situated quite near to the posterior border of the crown, and its
posterior arm is short.

M® varies in the same ways as the other molars. The bay in the buccal edge
varies in depth. The mesostyle never shows the basal swelling. The crest joining
the protoconule to the protocone is absent in only one specimen and present in
eight ; in M 14203 it is as strongly developed as on M2. The crista is present in six

EAST AFRICAN CHALICOTHERES 179

specimens, definitely absent in one and probably absent in another specimen. The
crochet is present in M. 14203 and probably two other specimens. The transverse
crest in the postfossette is present in only one out of eight specimens.

Fic. 2. Upper molars of Chalicotherium vusingense. a. Left M! and M?, R 1382.51. B
Left M3 from Koru, BMNH. Mr4202. c. Right M!, Roo9.47. v. Left M2 and M3 from
Koru, BMNH. Mr4203. &. Left M2, worn, from site R 91. F. Left M3, from site R 38.
c-J. Left M2, R 1382.51, buccal, lingual, posterior and anterior views. All x I.

180 EAST AFRICAN CHALICOTHERES

Specimens M 14202 and R 533.51 stand apart from the others in their greater
breadth, and are considered to belong to the large form, even though they are not
significantly greater in length. M 14202 fits with M, of R 1782.50, which is also
believed to belong to the large form (see below).

Comparisons. (Text-fig. 1). Upper molars of the typical form of C. rusingense
are only about 60% as large as those of typical C. grande from Sansan, but are
similar in size to those of C. pilgrimi. Molars of Schizotherium priscum resemble
in size those of the large form of C. rusingense ; M?! of S. turgaicum (Borissiak 1921)
is smaller than in C. vusingense (17:5 X17 mm.).

The length/width indices of the upper molars of C. grande (M1 103-109, M? 104-111,
M® 93-109) are not significantly different from those of C. rusingense (M* 93-107,
M? 100-110, M® 97-107), and in C. pilgrimi M? has an index of 106. In Schizo-
therium priscum M? and M® are typically a little narrower (indices 110-115), but there
is less difference in M1 (indices of two specimens 98 and 112).

In C. rusingense M? is larger in comparison with M! than in C. grande, C. pilgrimi
or S. priscum. Indices of comparable measurements on the two teeth show the
following ranges: C. rusingense (3 specimens) 127-138, C. grande (3 specimens)
114-131, C. pilgrimi (I specimen) 112-130, S. priscum (2 specimens) 113-127.

C. rusingense resembles C. grande in the displacement of the paracone and metacone
from the buccal side of the crown. In C. pilgrimi and S. priscum these cusps are
more buccal in position, and their buccal slopes are steeper. Moreover, in the two
latter species the protoconule is placed about equidistant from the tips of the
paracone and the protocone, whereas in C. rusingense and C. grande it is nearer the
paracone.

In all known specimens of S. priscum the protoloph continues over the tip of the
protoconule to the tip of the protocone, although between these cusps it dips to form a
notch. The same condition is found in C. filgrimi. In the other species of
Chalicotherium the connection between the protoconule and the protocone is
frequently broken, less often in C. rusingense than in C. grande. The connection is
complete in a large specimen of C. gvande from Cournon, but in six individuals from
Sansan that part of the crest which passes up the anterior slope of the protocone is
very weak or completely absent. In C. rusingense this part of the crest is retained,
and it is the crest on the lingual slope of the protoconule that disappears when the
connection is broken.

The crista is present on all molars of S. priscum that are sufficiently unworn, and
it is also present on M! and M? of the holotype of C. pilgrimi. It occurs in the
majority of specimens of C. rusingense and C. grande, but is sometimes absent. The
crochet is much less common. It was not observed in S. priscum, C. pilgrimi or
C. grande, but is present in a few specimens of C. vusingense, and Wehrli (1929)
recorded its presence in one specimen of M? of C. goldfussi. The small rib on the
lingual side of the ectoloph in the postfossette is present on all known molars of
S. priscum ; in C. rusingense it is much more common on M! than on M$; in C.
salinum it occurs on the holotype M%. It is uncommon in C. grande where it was

EAST AFRICAN CHALICOTHERES 181

found in only one specimen (M? and M$), and Wehrli (1929) noted it in a few speci-
mens of M3 of C. goldfussi. It is not present on M? or M? of the holotype of
C. pilgrimi.

The rib on the buccal slope of the paracone is present in all specimens of
C. rusingense and S. priscum. It is also present in C. pilgrimt and C. salinum,
but it is weaker and sometimes absent in C. grande and C. goldfussi. S. priscum
differs from the species of Chalicotheriwm in possessing traces of a buccal cingulum
between the parastyle and the mesostyle.

The upper molar roots of C. grande have not been described and are not visible in
material that I have examined. The lingual root of C. goldfussi (one of Kaup’s
specimens, seen as a cast) and the three roots of M$ of Nestoritherium sinense are very
much like C. rusingense. In two specimens of M® of S. priscum at Paris a small
supernumerary root is present, immediately to the lingual side of the anterobuccal
root ; this was not observed in C. rusingense.

Upper Premolars (Text-figs. IC, 3)

The three premolars are preserved together only in the holotype : in addition
there are 31 isolated teeth of which only one (R12.48) may definitely be identified
as P?. As P* and P* resemble each other in morphology, and differ only in size and
proportions, the overlap of their ranges of variation makes it impossible to identify
every specimen with certainty. By plotting the lengths or widths on arithmetical
probability paper (Harding 1949) the presence of two types of teeth in the collection,
in nearly equal numbers, was confirmed, and the mean dimensions and standard
deviations of P? and P* could be estimated. (Table III.)

In the holotype the total length of the premolar series is 38 mm., or 51% of the
length of the molar series.

TABLE III.

Upper molars of C. rusingense, inclusive of large form.

Length Width

N m s V N m s Vv
M3 7 25°3 I:07 4:2 8 24°8 1°65 6:7
M? 9 26°5 1°85 7:0 II 25°0 1°48 5:9
M? 9 20°4 1°25 6-1 12 19°9 1°47 74
1p at 13°2 0-76 5:8 me 18-1 IIo 6-1
124) II'5 0°53 4°6 14°7 I-04 TRI
Pp 2 9'7 _- -— 2 9:2 — —

The width of P* of the holotype is 92° of that of M1, but it is much shorter,
its width/length ratio being 1:37. In the largest of the isolated premolars the
width/length ratio reaches 1-44. P% of the holotype is a little shorter than P4

182 EAST AFRICAN CHALICOTHERES

and much narrower : its width/length ratio is 1:16. The narrowest of the isolated
specimens identified as P? has a ratio of 1-12.

The buccal edge of P* and P® usually shows a slight bay. The posterior edge
is evenly convex, reaching its most posterior point at the metastyle, to the buccal
side of the middle line of the tooth. The lingual edge is evenly rounded, but the
anterior buccal apex is the most acute of the three apices of the outline. The anterior
edge is straighter than the posterior one, and recedes posterolingually, especially
in teeth referred to P’. Owing to wear or breakage of the parastyle and metastyle
the anterior and posterior borders of isolated teeth often appear nearly parallel.

There are normally two roots, one anterobuccal in position and circular in section,
and the other a broad, flattened structure which extends along the posterior side
of the tooth. The posterior root appears to represent the lingual and posterobuccal
roots fused together. In two specimens these roots are separate, so that there are
three equal roots. In two others, both the buccal roots have united with the lingual
root to give a single root, V-shaped in cross-section, having a deep cleft on its
buccal side.

The ectoloph, consisting of parastyle, paracone and metacone, occupies the
buccal half of the crown. The parastyle is situated farther buccally than the para-
cone, more so on P4 than on P%. There is no mesostyle, and the buccal cingulum
is vestigial or absent. The buccal surface of the ectoloph is steeper than on the
molars ; a rib usually runs down it from the tip of the paracone, as on the molars.
The metacone is lower than the paracone, the two cusps being separated by a
notch worn by the hypoconid of the lower premolar. As completely unworn
premolars have not been found, it is uncertain how far the apparent apex of the
metacone is an artefact due to the cutting of the notch. In P® of the holotype and
in some isolated teeth the notch is weakly developed, and the metacone then appears
as an angulation situated rather high up on the posterior side of the paracone.
P% possesses an important area of wear on the lingual side of the posterior part of
the ectoloph, due to the anterior part of the trigonid of P,. The corresponding
wear on P* is small, and develops rather late in the life of the tooth. Accordingly,
the metacone appears to stand farther forward on P? than on P4.

In lightly worn teeth the protoloph is seen to join the ectoloph midway between
the paracone and the parastyle, as in the molars, but in severely worn teeth the
protoloph appears to arise directly from the paracone. The protocone of the molar
is represented by the deuterocone of the premolar, a stout cusp, flattened on its
buccal side and crested anteriorly. It is linked to the metacone by the metaloph,
but is separated from the protoconule by a valley. As on the molars, this valley
is frequently crossed by a crest that arises from the protoconule. This crest is
distinct in the holotype and in eleven of the isolated teeth ; it is absent or very weak
in 13 of the isolated teeth. There is no hypocone on P4 or P*. The anterior and
posterior borders of the crown are occupied by prominent cingula, elevated near
the middle line of the tooth. In M 14221 (P%) the posterior cingulum continues
as a ridge up the posterior surface of the deuterocone, but in other specimens this
ridge is indistinct or absent, and the cingulum ends at the base of the deuterocone.

EAST AFRICAN CHALICOTHERES 183

There is no lingual cingulum. In the least worn specimens a crista can be seen on
the posterolingual side of the paracone. In two specimens a short ridge, probably
corresponding to the crochet of the molar, extends into the central basin from the
metaloph ; it is absent in five other specimens.

The two specimens of P? are both rather severely worn. The crown is triangular,
slightly longer than broad, with the lingual apex situated near the posterior end.
In the holotype, P? has 81% of the length of P*. The isolated specimen has two
roots, arranged like those of typical specimens of P* and P*. In both specimens
the parastyle is low and weak, and the paracone is placed in the anterior half of the
crown, but no metacone can be distinguished, perhaps due to wear. There is no
buccal cingulum. The buccal slope of the paracone bears a vertical rib. The
whole of the lingual face of the ectoloph posterior to the paracone is occupied by
a large area of wear produced by P;. Owing to wear, details of the lingual part
of the crown are obscure. The deuterocone seems to be placed rather far back
on the crown, and to have taken part in the formation of a metaloph, like the hypo-
cone of the molar. The protoloph is probably reduced or absent. A posterior
cingulum is present.

Comparisons (Text-fig. 1). In Schizotheriwm priscum the premolars are larger
in comparison with the molars : the length of the premolar series is about 56%
of that of the molar series, compared with 51% in C. rusingense. I have been
unable to find a complete upper cheek dentition of typical C. grande, but in the type
of C. grande rhodanicum (from Depéret’s figure) the percentage is 45, and in the
Nikolsburg specimen of C. goldfussi figured by Abel (1922) it is 42.

Fic. 3. Chalicotherium rusingense. A, basal view of P4-M® to show arrangement of roots.
B, right P4, R 485.51, crown view. c, the same, anterior view. D, left P?, from Koru,
BMNH. Mr4221, crown view. E, F, right milk-molars, R 269.48 and R 65.50. G, H, ab-
normal premolar from Napak, crown view and anterior view. All x 1, except a x 4.

184 EAST AFRICAN CHALICOTHERES

In S. priscum P* is more equal to P* (length index P%/P4 in two specimens of
S. priscum 93 and 104 ; in the holotype of C. rusingense it is 89). In C. grande
this index ranges from 87 (Crusafont & Villalta 1942) to 85 (measured from the
figure of Depéret 1892); in the Nikolsburg specimen of C. goldfussz it is 82.

Differences in the pattern of P* are slight. They concern mainly the protoloph
which in Schizotherium continues to the tip of the deuterocone, whereas in Chalico-
therium it tends to be interrupted, probably in correlation with the protoloph of
the molars. In Schizotherium P® is similar to P4 in pattern, differing only in being
slightly narrower. In C. rusingense P® is more definitely narrower, with a more
oblique anterior edge, but its pattern still resembles that of P*. In C. grande,
C. goldfussi and C. brevirostris there is a further distinction in that the protoloph
of P® is lower in relation to the ectoloph.

The alveoli in a maxilla of C. grande in Paris show that P* and P* each possessed
a broad posterior root and a smaller anterobuccal root, as in C. rusingense. This
is also true of Spanish specimens (Villalta & Crusafont 1943).

P? of Schizotherium priscum has a distinct protoloph, which branches from the
ectoloph between the parastyle and the paracone and runs to the tip of the protocone
asin P’. InC. grande (Crusafont & Villalta 1943) the protoloph is weakly developed.
C. rusingense seems to approach C. grande in this respect. The teeth of C. grande
identified by Wegner (1913) as P! and P? are probably P? and P® respectively.

? Abnormal specimen of P*. (Text-fig. 3G, H.)

An upper premolar from Napak measures 12 X 14 mm. (width/length ratio 1-17).
It differs from upper premolars of C. rusingense in the presence of a groove on the
posterolingual surface of the lingual root (which is fused with the posterobuccal
root), associated with a nick in the posterolingual enamel border. The ectoloph
shows the normal pattern of P%, but there are differences in the lingual part of the
crown. The protoloph extends to the lingual side of the crown, and ends in a
protoconule placed immediately anterior to the deuterocone. The metaloph forks :
its anterior branch runs to the tip of the deuterocone, and the posterior branch
interrupts the posterior cingulum, above the nick in the enamel border. The
anterior cingulum ends lingually at the base of the protoconule.

A similar tooth from the Upper Miocene of Steinheim was referred by von Koenigs-
wald (1932) to Metaschizotherium bavaricum, and another specimen with the same
characters was described by Roger (1885). These European teeth are much larger
and more transverse than the Napak specimen. It is possible that this represents
an African species of Metaschizotherium (i.e. Phyllotillon), as I suggested in an earlier
report (Butler 1962), but in the absence of other evidence for the existence of
Phyllotillon in Africa it now seems to me preferable to interpret it as an abnormal P#
of Chalicotherium rusingense.

Upper milk-molars. (Text-fig. 3E, F.)

Some isolated upper molariform teeth of small size are probably milk-molars.
R 269.48 is tentatively identified as Pd’. It measures 16 x 15:5 mm. It is lightly
worn. The bay in the buccal edge is situated more anteriorly than in M!; the

EAST AFRICAN CHALICOTHERES 185

lingual root tapers markedly towards the tip and is nearly equal in length to the
anterior buccal root. As on some specimens of M!, the protoconule is connected to
the anterior side of the protocone by a low but distinct crest, and there is a small
cross-crest in the postfossette.

R 65.50 is much smaller (13-5 14mm.) and is possibly Pd*. It is rather severely
worn, and its unworn length would be greater. The roots are broken off, but the
crown appears to be similar to R 269.48.

A third specimen, R 631.47, measures 19 < 18-5 mm., approaching the lower limit
of size of M!. Its lingual root resembles that of M!, but the anterior border of the
tooth is more oblique. This could be either an abnormally small M! or an example
of Pd? of the large form. An incomplete specimen, R 697.51, is similar in size.

If the identification of these teeth is correct, it would follow that the milk-molars
of C. rusingense are larger in comparison with M! than in C. grande, where Pd? is
about 65% and Pd? about 55% as long as M! (Villalta & Crusafont 1943). In
Schizotherium priscum, to judge from the figure of Stehlin (1905), the milk-molars
are less reduced than in C. grande and may have resembled those of C. rusingense in
relative size.

In shape, however, the milk-molars of S. prviscum are narrower, especially Pd?.
Those of C. grande and C. wetzleri are more like C. rusingense. The small crest in the
postfossette occurs in S. priscum, and also in the supposed Pd? of C. grande rhodani-
cum (Depéret 1887).

Lower molars. (Text-figs. 4,5 ; Tables IV, V, pp. 190, 191.)

The mandible F3608 contains all the molars of both sides, in R 410.55 the right
series is preserved in a mandible fragment, and R 1782.50 consists of a collection of
separate cheek teeth from the right side which probably belong to one individual.
M, and M, of R 1782.50 are considerably larger than those of the other two specimens,
and fit upper molars referred to the large form. Seven other specimens show single
teeth or parts of two adjacent teeth in mandible fragments, permitting identification.
There are also six fairly complete isolated lower molars (including one specimen from
Napak) and numerous fragments, consisting mostly of isolated trigonids or talonids.

The three complete sets show that M, is only 73-77% as long as M,. It is however,
proportionately wider : the trigonid width is 58-62% of the length of the tooth,
compared with 53-55% in M,. Only one mandible fragment (R 520.48) is identified
as containing M, ; the tooth is broken anteriorly, but its talonid agrees closely with
M, of R 1782.50, and it is therefore referred to the large form. There is also an
isolated talonid of the typical form (R 68.40).

Six specimens contain M, or M, with a fragment or alveolus of an adjacent molar,
permitting identification. These, together with the specimens showing the complete
molar series, show that in the typical form M, (4 specimens) ranges in length from
23°4-24°6 mm., and M, (4 specimens) from 24-4-26:°8 mm. In F 3608 and R 410.55
M; is about 3 mm. longer than M,. M, is longer in proportion to its width (across the
trigonid) than M,. In R 1782.50 the difference in length is only 0-4 mm., and it
would appear that, as in the upper dentition, the last molar of the large form is
proportionately shorter, though its width exceeds that of the typical form.

186 EAST AFRICAN CHALICOTHERES

Fic. 4. Right lower molars of Chalicotherium. A, C. pilgrimi, My, BMNH. M12167. B,
C. rusingense, Rusinga, F 3608. c, C. gvande, Paris specimen from Sansan (left teeth
reversed). D, C. grande, lingual view of M,, BMNH. M4o82r. E, C. styviacum, lingual
view of M>, from cast, BMNH. Mi2112. All x 3.

Some of the isolated molars, and all the incomplete teeth, cannot be definitely
sorted into second and third molars. Recourse was therefore made to probability
paper, by which means and standard deviations could be estimated, assuming equal
numbers of M, and Mg in the collection.

Altogether, 5 independent specimens containing lower molars are referred to the
large form, as against 22 referred to the typical form.

The three molars are so much alike that a single description will suffice for all.
There are two roots, flattened from front to back and inclined somewhat posteriorly.
The posterior root is the stouter of the two, especially in Mg, where its posterior
surface is more rounded. The length of the roots on M, and M, is 20-24 mm. A
low inter-radicular crest is present on the base of the tooth.

Of the two V-shaped buccal cusps, the protoconid is a little lower than the hypo-
conid and occupies a smaller area on the crown. The anterior crest of the protoconid
falls rapidly as it passes in a curve along the anterior border of the crown, and at its
lingual end it becomes a cingulum ledge anterior to the base of the metaconid.
There is no paraconid, though a notch may be worn in the crest to give the appearance
of that cusp. A narrow cingulum on the anterior edge of the crown does not extend
to the buccal side of the protoconid. The posterior arm of the protoconid remains
nearly horizontal, crossing the crown to join the metaconid. The latter cusp is
higher than the protoconid ; its base extends forward so as partly to close the
trigonid basin. Closely applied to the posterior surface of the metaconid is the
metastylid, the tip of which is lower than that of the metaconid. In three specimens
the metastylid is represented only by a sharp posterior crest of the metaconid. The
arms of the hypoconid diverge at a greater angle than those of the protoconid. The
anterior arm ends between the metaconid and the metastylid, so that the latter cusp

EAST AFRICAN CHALICOTHERES 187

projects backwards partly closing the talonid basin. The posterior arm of the
hypoconid runs to the tip of the entoconid, a conical cusp, somewhat lower than the
metaconid, and placed at the posterolingual corner of the crown. The trigonid
basin opens lingually anteriorly to the base of the metaconid, and the trigonid basin
opens between the metastylid and the entoconid. The posterior edge of the crown
is occupied by a cingulum, somewhat variable in development. When best developed
it rises towards the lingual side to form a vertical rib on the posterior face of the
entoconid ; this rib represents the hypoconulid.

Fic. 5. A-£, Right M, of Chalicotherium rusingense from Rusinga, X I, A, crown view ;
B, buccal view ; c, lingual view ; D, anterior view ; E, posterior view. F, lower pre-
molars of C. rvusingense, R 1782.50 x I. G, M,—P3 of C. grande, BMNH. M4o821 and (P3)
a Paris specimen, x 3. H, M,—P3 of C. goldfussi, from cast, BMNH. M2719, x 3.

The effect of wear is to expose a strip of dentine on the crests of the protoconid
and the hypoconid. These cusps are thus reduced in height. The metaconid and
entoconid however are worn mainly on their buccal sides, and their height is reduced
more slowly.

Comparisons. The lower molars of C. rusingense are much smaller than those of
C. grande or C. wetzlert, but a little larger than those of C. pilgrimi. Typical speci-

188 EAST AFRICAN CHALICOTHERES

mens are similar in size to those of Schizotherium turgaicum and somewhat smaller
than those of S. priscum.

In Schizotherium the hypoconulid of M, is enlarged to form a posterior heel,
probably the relic of a larger structure present in Eomoropinae. In C. rusingense,
as in C. grande and other species of Chalicother1um, M, resembles Mg.

The metastylid is distinctly developed in Schizotherium, as well as in C. pilgrimi,
C. wetzleri and (with a few exceptions) in C. rusingense. In C. grande and other late
species it is more or less merged into the metaconid.

The width/length index of the lower molars is somewhat greater in C. grande
(56-58 in specimens of M, from Sansan) than in C. rusingense (M2 : 53-55). Wehrli’s
(1939) measurements show that in C. goldfussi still broader molars can occur (M, :
55-62). Comparatively narrow molars (index of M, below 55) occur in C. weézlert,
C. pilgrimi and species of Schizotherium.

Molar Occlusal Relations. (Text-fig. 6.)

The functional inter-relations of the upper and lower molars were studied by
examining the wear facets and by fitting teeth together.

In the centric position, in which the teeth are pressed together as closely as possible,
the lower molar covers the lingual part of the upper molar, the inner borders of both
teeth being in line. The inter-relations of the cusps in the centric position may be
tabulated as follows :—

Hypoconid tip Centre of central valley, between tips of paracone and
metacone.

Protoconid tip Cingulum anterior to the protoconule.

Entoconid Groove between protocone and hypocone.

Metaconid-metastylld Space between protocone and the more anterior hypocone.

Paracone tip Buccal side of tooth, in valley separating protoconid and
hypoconid.

Metacone tip Embrasure between two lower molars, partly filled by
posterior cingulum.

Protoconule Buccal side of metastylid.

Protocone Between metastylid and entoconid.

Hypocone tip Against anterior arm of protoconid, in which it wears a
notch.

During chewing, the crests of the protoconid and hypoconid slide up the lingual
surface of the ectoloph. This can take place only when the lower jaw is displaced
to the lateral side of the centric position. The movement was almost certainly ectal,
starting when the lower teeth are placed so that the protoconid and hypoconid
touch the parastyle and mesostyle respectively ; from this position the lower teeth
move medially, upwards and slightly forwards to the centric position.

The facets of wear produced in chewing can without difficulty be homologized
with those distinguished in other perissodactyls (Butler 1952).

EAST AFRICAN CHALICOTHERES 189

(€ 3a

Fic. 6. Molar occlusion of Chalicotherium rusingense.
imposed in centric relation.

3b 10 ?

A, upper and lower molars super-
B, C, wear facets on the molars.

Io.

Lower facet
Near the edge of the anterobuccal surface
of the anterior crest of the protoconid.
Posterior surface of the protoconid-meta=
conid crest.
(a) Buccal surface of metaconid and meta-
stylid, near the tip.

(b) Posterior face of metastylid, near the
tip.

Upper facet
Lingual face of the posterior crest of the

metacone.
Anterior face of paracone and protoconule.

Lingual face of protoconule.

Anterior crest of protocone.

(These two facets are variable in development, and may be absent, especially

3 (b).
may unite.)

(Metaconid-hypocone contact is absent.)
Edge of anterior crest of protoconid.

Anterior face of the buccal part of the
hypoconid-metastylid crest, near the
edge.

Posterior face of the hypoconid-entoconid
crest.

A posterobuccal facet on the entoconid,
involving the vertical rib.

Anterior surface of entoconid.

When the protocone-protoconule crest is well developed the two facets

Edge of posterior crest of hypocone.

Posterolingual face of the paracone- meso-
style crest.

Anterior face of metacone and metaloph.

Anterolingual face of hypocone, near its tip.

Posterior crest of protocone.

(Contact slight and sometimes absent.)

Lingual surface of hypoconid.

Of these, 1, 2, 6 and 7 from the main chewing surfaces.
lingual cusps (3, 8 and 9g) are probably significant only as stops.

Buccal surface of protocone.

Contacts between the
When the lower

jaw swings to the lingual side of the centric position, contacts 5 and 10 would ensure
occlusal balance while the teeth on the opposite side of the mouth are in use.

190 EAST AFRICAN CHALICOTHERES

Lower Premolars. (Text-fig. 5.)

Lower premolars are poorly represented in the collection. The mandible F 3608
shows their roots in the left ramus ; three isolated teeth (R 1782.50) probably
represent P,—P, of a single individual, but they are in poor condition. Two more
worn and isolated teeth (R 738.50 and R 739.50) may be Ps; and P, of another
individual ; they differ in some respects from R 1782.50 ,and may not be correctly
identified. Finally, there is a broken specimen of P, (R 12.48).

F 3608 shows that P, was absent. The total length of P,—P, is 37 mm., or 53%
of the total length of the molars. All the premolars are two-rooted ; their length
diminishes from P, to P,.

In R 1782.50, Py is shorter and proportionately broader than M, (15.5 x I0 mm.).
Its roots are flattened anteroposteriorly, but are less distinctly separated at the base
than those of the molars. The crown-pattern differs from that of the molars in the
following respects : the anterior arm of the protoconid runs in a rather more anterior
direction to the middle of the anterior edge of the tooth, where it turns lingually, fal-
ling rapidly to form a cingulum that merges into the anterior base of the metaconid ;
there is no metastylid ; the hypoconid is much lower than the protoconid, and the
crest which connects the hypoconid to the buccal surface of the metaconid is corres-
pondingly low ; the entoconid (broken off) appears to have occupied a smaller
proportion of the crown than in the molar, and the posterior cingulum is probably
absent.

TABLE IV.

Measurements of lower molars of two specimens of C. rusingense.

F 3608 1782.50
Trigonid Talonid Trigonid Talonid
Length Width Width Length Width Width
M, 26°8 14:0 13°6 26:8 I4°4 14°3
M, 23°8 13°0 12°7 26:4 14:0 13°9
M, 183 105 II'5 19°8 — —

P3 of R 1782.50 is smaller in all dimensions than P, (13 x 9 mm.), and is much less
molariform. The anterior arm of the protoconid forms at the anterior end of the
crown an angulation that is probably to be interpreted as a small paraconid. The
metaconid does not rise to a distinct point, but is united with the protoconid to form a
ridge that runs transversely to the crown and slightly backwards. There is no meta-
stylid. The hypoconid is only about half as high as the protoconid, and, though the
postero-lingual part of the crown is broken, the entoconid must have been very low
and cingulum-like. On P, (10 x 6.5 mm.) the protoconid is the only well-developed
cusp. An anterior ridge inclined lingually represents the paraconid, and a lingual

EAST AFRICAN CHALICOTHERES 191

ridge the metaconid. The talonid is rudimentary. From the small hypoconid a ridge
passes forward to merge with the posterobuccal surface of the metaconid ridge.
There is a low, cingulum-like entoconid.

R 738.50 differs from P,4 of R 1782.50 in its greater posterior breadth (16 x 11.8
mm.), due to the presence of an accessory cusp on the buccal side of the hypoconid
(probably an abnormality). The tooth is very worn, and the presence of a metastylid
cannot be affirmed, though it is probable. The entoconid, lower than the hypoconid,
stands rather independently from the other cusps. There is no posterior cingulum.
R 739.50 (13.3 X 9 mm.) is a specimen of P3 which agrees with R 738.50 in the
presence of a small cingulum cusp buccal to the hypoconid, and it probably comes
from the same individual. The entoconid is a small elevation on a cingulum at the
posterolingual edge of the crown.

In R 12.48, which is a specimen of P,, most of the trigonid has flaked away. The
hypoconid is even more reduced than in R 1782.50, and the entoconid is represented
only by a fragment of cingulum.

Comparisons. The premolar/molar index of C. rusingense (53) is close to those of
C. wetzleri (54 in the Bollingen specimen) and Schizotherium priscum (54, from
Osborn’s figure, 1913) ; it is exceeded by S. cf. avitum (59, Teilhard de Chardin 1926).
In some specimens of C. grande the index is reduced (47 in two specimens from
Sansan, 44 in a Spanish specimen figured by Villalta & Crusafont 1943).

In Schizotherium priscum (Osborn 1912) and S. turgaicum (Borissiak 1928) P,
possesses a weak metastylid, possibly present in one of the specimens of C. rusingense.
P, of S. priscum and S. cf. avitum is more equal to P, than in C. vusingense, and more
similar in pattern ; in C. grande P, is smaller and simpler than P,, its metaconid
being incompletely differentiated, as in C. rusingense. P, of C. grande is more
reduced than in C. rusingense ; the metaconid ridge is weak and the roots may fail
to separate.

Thus reduction of the premolars has proceeded farther in C. rusingense than in
Schizotherium, but not quite as far as in C. grande.

TABLE V.

Dimensions of lower molars of C. rusingense, inclusive of large form.

N m Ss V
M, + M, Length 17 24°9 mm. 1°75 7:0
Trigonid width 24 13°4 mm. 0°88 6:6
Talonid width 20 13°3 mm. 0°54 4°1
(range)
M, Length 3 18-4 mm. 17:2-19'8
Trigonid width 2 10°6 mm. 10*5—10°7
Talonid width 3 II°5 mm. 10:7-12°4

Canines and Incisors. (Text-figs 7, 9.)
In the holotype a diastema of 26 mm. separates P? from the upper canine. This
is a small, curved tooth, measuring 11-5 < 10:3 mm. at the base of the crown, and

192 EAST AFRICAN CHALICOTHERES

2a ‘Gis
9 Zags aa i

‘
t

Fic. 7. Partial reconstruction of the face of Chalicotherium rusingense, based on the
holotype. Side view and palatal view, x 4.

19 mm. from the tip to the posterior border of the alveolus. It is placed procumb-
ently in the jaw, its root making an angle of 60° to the line of the cheek teeth. The
tipis blunt. There is a posterior crest near the tip, and a more rounded ridge on the
buccal side (corresponding to the rib on the buccal slope of the paracone in the
premolars and molars). The lingual surface is poorly preserved, but there was
probably a short lingual crest near the tip. The anterior surface is evenly rounded.

Anterior to the canine the alveolar border is preserved for a length of 12 mm., but
it contains no teeth. The premaxilla is very slender, and though its tip has been
broken off it is unlikely that any upper incisors were present.

In F 3608 and R 283.48 a lower canine root can be seen on either side. The lower
canine must have been smaller than the upper canine, measuring in section about
10 X 7mm. It was procumbent, and was separated from P, by a diastema, 26 mm.
long in F 3608 and 28 mm. in R 283.48. Three incisor alveoli can be seen on each
side of F 3608, immediately anterior to the canine. Their labial walls are broken
away, but it is clear that the alveolus for I, was the largest.

The incisor from Malembe, Congo Republic, described by Hooijer (1963) as an
upper incisor of Macrotherium (?) spec., is not referable to C. rusingense. It is much
too large to fit even into the largest lower incisor alveolus. The molar fragment

EAST AFRICAN CHALICOTHERES 193

from Malembe is also much larger than in C. vusingense : its talonid width is 25 mm.,
compared with a mean talonid width of 13-3 mm. for M, and Mj of C. rusingense.

Comparisons. The anterior teeth of Schizothertum priscum are unknown. An
isolated tooth tentatively identified by Teilhard de Chardin (1926) as the lower
canine of S. cf. avitwm measures 18 < 9:5 mm. ; this is larger in proportion to M,
than in C. rusingense. The juvenile mandible from St. Gérand-le-Puy described by
Filhol (1879) appears to belong to Phyllotillon.

A juvenile mandible of C. grande from Sansan, figured by Filhol (1891) and now in
Paris, shows alveoli for a canine and three incisors. These probably belong to the
milk dentition, for gubernacular foramina are present in association with the first
two incisors. Id, is the largest of the incisors, and the canine is larger than any of
the incisors. One of Lartet’s specimens of “‘ Amisodon magnum” contains the
broken alveolus of a lower canine, separated from P, by a diastema 29:5 mm. long.
An isolated tooth lying shortly anterior to the lower jaw of the skeleton of C. grande
described by Filhol (1891) may be an incisor (see Viret 1958, pl. 1). Nothing is
known of the anterior upper dentition of C. grande. A lower milk canine appears
to have been present in C. goldfussi, if C. baltavarense is correctly identified with that
species (see p. 168). In C. brevivostyis upper canine and incisors are absent, as in
Nestoritherium sivalense.

Face and Palate. (Text-fig. 7 ; Table VI.)

Of the skull, only part of the face and palate are known, mainly from the holotype,
but supplemented by fragments of maxilla.

Anterior to M! the length of the face is 1:23 times the length of the upper molar
series. The external narial opening extends back to above P? ; it is flanked by a
slender process of the small premaxilla. The zygomatic process arises above the
posterior end of M?, and the anterior end of the orbit was probably situated above
the anterior part of M*. The infraorbital foramen is preserved only in R 483.51,
where it opens above M1. In other specimens the floor of the infraorbital canal can
be traced back to the orbit. The canal and the foramen are situated fairly high on
the face, about 25 mm. above the alveolar border of the cheek teeth. The maxillary
sinus is represented by a small cavity between the infraorbital canal and the roots
of the molars.

TABLE VI.

Measurements of face and palate, C. rusingense, holotype.

Antemolar length . 5 ; : : : . 123 mm.
Length diastema 2 . . é : : : 22 mm.
M1_M§ inclusive : : : : Z ; Fi 75 mm.
P2_P# inclusive ; F : : : : 3 38 mm.
C—P* inclusive . ¢ : 3 ; 80 mm.
Infraorbital Feeameneeelveotan orden 3 3 ‘ 32 mm.
Lower edge of orbit—alveolar border . j ‘ : 41 mm.
Height of zygoma_ . 3 ; : 30 mm.

Width of palate between first molars (est. Nc . . 58 mm.

194 EAST AFRICAN CHALICOTHERES

The palate is transversely arched. Its width between the first molars must have
been about 45 mm., and it probably increased somewhat in width posteriorly. It
is pierced by a foramen medially to M!. The posterior border of the palate has not
been preserved.

Comparisons. The infraorbital foramen is above the anterior part of M?! in C.
rusingense, C. grande, C. brevirostris and Schizotherium priscum, but in C. pilgrimi,
probably due to the youth of the specimen, it is a little farther forward, above the
posterior part of P*. The height of the foramen on the face is least in Schizotherium,
most in C. grande : the index, distance of foramen from teeth/molar length, is 25 in
S. priscum, 29 in C. pilgrimi, 32 in C. rusingense and 43 in C. grande.

In S. priscum and C. grande the zygoma arises above the posterior end of M?, as in
C. rusingense, but in C. brevirostris it arises a little farther forward (mid M#?) ; in
juvenile specimens, such as the holotype of C. pilgrimi, it reaches the level of the
anterior end of M?.

The length of the face is unknown in Schizotherium and in C. grande. It has almost
certainly been shortened in C. brevirostris, for in this species it is much shorter than
in C. rusingense. The anterior margin of the orbit in C. brevirostris is above the

Fic. 8. Mandibles of Chalicotherium. A, C. vusingense, from Rusinga, F 3608. B, C.
wetzleri (holotype of Palaeotheriwm schinzii von Meyer) froma cast. Cc, C. gvande, Paris
specimen from Sansan. All x 4.

EAST AFRICAN CHALICOTHERES 195

posterior part of M*. Unfortunately the known skulls of C. grande are so badly
crushed that the exact position of the border of the orbit is uncertain. The distance
between the orbit and the infraorbital foramen appears, however, to be greater in
C. rusingense than in either C. grande or C. brevirosins.

Mandible. (Text-figs. 8,9 ; Table VII.)

F 3608 is the only specimen in which more than a fragment of the mandible is
preserved. It consists of both horizontal rami, but the posterior part of the mandible
has been broken off on both sides. R 283.48 shows the region of the symphysis.

The ramus is moderately deep, its depth increasing posteriorly. Below the molars
the rounded lower border is very slightly concave in lateral view, falling and be-
coming sharper behind M, to indicate the angular process (most of which is missing).
The lateral surface below the teeth is nearly flat, but shows a weak longitudinal
groove about 14 mm. above the lower border. This groove fades out below the
premolars, where there is a slight convexity. The masseteric fossa is very flat and
hardly noticeable. The coronoid process appears to be inclined at an angle of 45°
to the alveolar border. Internally, the ramus is moderately convex below the molars;
about 15 mm. above the lower border there is a slight groove, presumably for the
mylohyoid muscle. The mandibular foramen is low, its lower border being 22 mm.
below the level of the alveolar border. The pterygoid fossa is very shallow.

Fic. 9. Chalicotherium rusingense, F 3608, symphyseal part of mandible, in dorsal and
ventral views, x }.

The two rami converge at an angle of 30°. The symphysis extends back to the
posterior end of P,. The symphyseal region is nearly in line with the horizontal
ramus, but shows a slight upward tilt. Its vertical depth is less than that of the
ramus, and there is a step in the alveolar border anterior to P,. The lower surface
of the symphysis is evenly convex in a transverse direction, and its upper surface is
concave to form a gutter. In the region of the diastema the alveolar border forms a
sharp ridge, which turns laterally immediately behind the canine, where it overhangs
the lateral surface of the jaw. The mental foramen is placed below the diastema,
about midway between P, and the canine. Above it is a small foramen, close to the
alveolar border.

196 EAST AFRICAN CHALICOTHERES

Comparisons. C. rusingense resembles C. grande and C. wetzleri in the general
shape of the horizontal ramus of the mandible. The anterior part of the mandible
of C. grande is known mainly from a juvenile specimen figured by Filhol (1891, pl. 44).
This differs from C. vusingense in the shorter symphysis and diastema. In an adult
specimen (Filhol 1891, pl. 45) the diastema is only 58% as long as the premolar series,
compared with 80°% in C. rusingense, and it is probable that the anterior part of the
mandible, and therefore also the tip of the snout, was more abbreviated in C. grande
than in C. rusingense. A further difference is that the mandibular foramen of C.
grande is in line with the teeth, whereas in C. rusingense it is at a lower level.

The mandible of Schizotherium is very poorly known. From the figure of Osborn
(1912) it may be seen that the alveolar border is stepped down anteriorly to P, as in
Chalicotherium. In Schizotherium sp. (Bohlin 1946) the symphysis ends a little
anteriorly to P,, and the diastema was evidently longer than in C. vusingense. In
this specimen the coronoid process appears to rise rather steeply, resembling
Eomoropus (Osborn 1913). In S. cf. avitum (Teilhard de Chardin 1926) the diastema
is longer than the premolar series, and the symphysis ends far anterior to Py, as in
Eomoropinae. Shortening of the anterior part of the mandible appears to be a
trend of chalicotherian evolution, and it is probable that C. rusingense is more
primitive than C. grande in this respect.

TABLE VII.

Measurements of lower jaw, F3608.

Antemolar length (est.) . : ; é ; : 95 mm.
Between M, and the canine alveolus . ‘ ‘ ; 63:5 mm.
Length of diastema . 6 : : 4 ; : 27°5 mm.
Length of symphysis (est.) : ; : : ; 63 mm.
Length M,—M, inclusive . 6 6 5 : : 70 mm.
Length P,—P, inclusive. : : . : ¢ 36 mm.
Depth at posterior end of M, (perpendicular to lower

border) . ‘ 2 : : : : : 49°5 mm.
Depth at anterior end of M, : : > 9 ; 34 mm.
Depth at diastema . : : ; : : ; 22 mm.
Width between canines . 5 : : : c 14 mm.
Minimum width behind canines . ; : 5 . 26 mm.
Width across M, talonids . ‘ : : : : 92 mm.

Scaphoid. (Text-fig. 10 A-F.)

The only specimen of this bone is F 2077, which belongs to the left side. It isa
proximodistally flattened bone with a distal (or ‘‘centrale’’) process, situated
towards the ulnar and dorsal (= anterior) sides. Its dimensions are : height 31 mm.,
dorsovolar length 31 mm., radio-ulnar width 44-5 mm. In proximal view, the bone
is transversely widened ; most of the proximal surface is occupied by the facet for
the radius. This facet is concave in a dorsovolar direction ; its ulnar edge meets the
proximal margin of the lunate facet in an acute angle, and its margin is slightly

EAST AFRICAN CHALICOTHERES 197

raised near the middle of the dorsal side and again at the ulnar end of the volar side.
The radial third of the proximal surface of the scaphoid forms the radial process, and
the middle of the volar side extends as a small volar process.

LIGA
1 AG,

Fic. 10. A-—F, left scaphoid of Chalicotherium rusingense, F 2077. A, proximal view ;
B, distal view ; c, radial view ; D, dorsal view ; E, volar view ; F, ulnar view. G-1,
corresponding views of scaphoid of C. gvande, Paris specimen from Sansan. All x }4.
Labelling of facets: J/.d., distal lunate ; /.p., proximal lunate; m, magnum; 17,
radius ; ¢, trapezoid.

198 EAST AFRICAN CHALICOTHERES

In dorsal view the scaphoid is wider than long. The dorsal surface is divided by
a ridge which runs from the elevation in the dorsal margin of the radius facet to the
distal process. This ridge divides a smooth, triangular proximo-ulnar area from the
remainder, which is roughened. The roughening is very marked in a line from the
radial process along the edge of the trapezoid facet, presumably for ligamentary
attachment.

The trapezoid facet occupies a large area on the distal side of the bone, extending
from the radial process to the radial side of the distal process. It is slightly saddle-
shaped, being weakly divided by a ridge which arises from the tip of the distal
process, near the dorsal side, and crosses the facet to end below the volar process.
Radially, the trapezoid facet does not reach the tip of the radial process, but it leaves
a small area of smooth bone that might have articulated with a trapezium.

On the ulnar face of the scaphoid there is a proximal facet for the lunate, but no
distal lunate facet, the ulnar surface of the distal process being rough. The magnum
probably articulated with a small convex area at the tip of the distal process.

Comparisons. The scaphoid of Schizotheriwm is unknown. In comparison with
C. grande, of which four examples were studied in Paris, the scaphoid of C. rusingense
appears to be compressed in a proximodistal direction. Its distal process is shorter
and less slender. In C. grande the proximal lunate facet is hardly indicated, but there
is a large distal lunate facet on the ulnar side of the distal process ; in C. rusingense,
on the other hand, the proximal lunate facet is well developed, but the distal facet
is absent. In Phyllotillon betpakdalensis (Borissiak 1946) and Movropus elatus
(Holland & Peterson 1913) both facets are equally developed, and this is probably
the primitive condition. The two species, Chalicotherium grande and C. rusingense,
agree in the cylindrical concavity of the radius facet, which is saddle-shaped in
Phyllotillon and flat in Moropus, and in the small and indistinct contact with the
magnum, the distal process terminating in a rounded point, instead of being truncate
as in the other genera.

Third Metacarpal. (Text-fig. 11 A-E.)

F 2070 is the proximal end of a right metacarpal III. The transverse diameter of
its head slightly exceeds the dorsovolar diameter (37°5 < 35°5mm.). The proximal
surface is crossed by two dorsovolar keels, which demarcate the rectangular facet
for the magnum. The ulnar keel is much the higher of the two. On its ulnar side
is the unciform facet, and the radial part of the proximal surface is occupied by a
facet for metacarpal II. The unciform facet extends onto the proximal surface of
the prominent dorso-ulnar process, which overhangs a cavity on the ulnar side of the
head of the metacarpal for articulation with metacarpal IV.

The facet for metacarpal II is triangular, tapering in a volar direction. It is
convex in a dorsovolar direction ; its volar part is approximately horizontal and its
dorsal part nearly vertical. The dorsoulnar part of the facet faces radially, extending
onto the radial side of the keel that divides it from the magnum facet. The meta-
carpal facet overhangs the radial side of the bone. The magnum facet is also
convex in a dorsovolar direction, but its dorsal part does not reach so far distally as

EAST AFRICAN CHALICOTHERES

<Se
So

Soe
SS

—

199

Fic. 11. A-£, right third metacarpal of Chalicotherium rusingense, F 2070. A, dorsal view ;

B, volar view ; C, ulnar view ; D, radial view ; E, proximal view.
views of C. gyande, Parisspecimen from Sansan. All x }.

F-J, corresponding

200 EAST AFRICAN CHALICOTHERES

the metacarpal facet, and it is bounded dorsally by a ridge. Transversely the
magnum facet is concave, extending up its marginal keels. In the unciform facet,
a dorsal part, which is concave, may be distinguished from a volar part, which faces
in an ulnar direction. The dorsal part is situated on the dorso-ulnar process. A
single facet for metacarpal IV occupies the proximal and radial sides of a pit on the
ulnar side of the head ; its dorsal part faces in a distal and volar direction, and its
volar part in an ulnar and somewhat distal direction.

The shaft is approximately quadilateral in section immediately below the head,
but at the broken end, 67 mm. from the most proximal part of the head, the section
is oval, somewhat flattened in a radio-ulnar direction. The surface of the bone near
the head shows areas of roughening: on the dorsal surface of the dorso-ulnar
process ; on the dorsal surface below the facet for metacarpal II, extending about
25 mm. distally ; on the radial side extending 18 mm. below the most distal part of
the facet for metacarpal II ; on the volar side below the magnum facet, where the
roughening forms a distinct prominence. The surface of the bone on the ulnar side
is badly preserved.

Comparisons. The third metacarpal of Schizotherium priscum was figured by
Filhol (1893) and described by Holland & Peterson (1913). A similar metacarpal
from Mongolia, referred to Schizotherium sp., was figured by Colbert (1935). In
both of these, the head of the metacarpal is smaller than in C. rusingense (cir. 25°5 X
27 mm. in Colbert’s specimen). The radio-ulnar width of the head is less than the
dorsovolar diameter, whereas in C. rusingense, and in C. grande, it is greater. The
magnum facet occupies a larger proportion of the proximal end. The articulation
with metacarpal II consists of two parts, a dorsal part, where the radial apophysis
of metacarpal II projects over the proximodorsal surface of metacarpal III (as in
Moropus), and a proximal part, which is narrower than in C. rusingense and is not
separated from the magnum facet by a crest. The unciform facet is more steeply
inclined and confined to the dorsal half of the bone (again as in Morvopus). Colbert’s
specimen also resembles Moropus in bearing two facets for metacarpal IV.

In C. grande there is much more resemblance to C. rusingense. The differences
noted are as follows : it is about one-third larger ; the keel separating the magnum
facet from the facet for metacarpal II is weak or absent ; the magnum facet is less
concave in a radio-ulnar direction. In other respects C. grande and C. rusingense
resemble each other and differ from Schizotherium : the proportions of the head :
the shape of the articulation for metacarpal II ; the extension of the unciform facet
to the volar side of the head, and its more horizontal inclination ; the union of the
facets for metacarpal IV.

Fourth metacarpal. (Text-fig. 12 A-E.)

There are two examples of the proximal end of metacarpal IV. The larger of the
two, from site R 106, fits against the third metacarpal described above. It measures
36:5 mm. in dorsovolar length and 30 mm. in width. The other specimen (R278.55)
is much smaller, (26-5 x 18-5 mm.) and probably juvenile.

EAST AFRICAN CHALICOTHERES 201

In proximal view the larger specimen has the form of a triangle, flattened in a
radio-ulnar direction. The most acute apex of the triangle is formed by the dorsal
apophysis, which supports the dorsal part of an elongated facet for metacarpal III.
The volar part of this facet is nearly vertical and faces radially. Most of the
proximal surface is occupied by the unciform facet, which is triangular and nearly
flat, but with its ulnar border somewhat elevated. It is separated from the volar
part of the metacarpal facet by a blunt ridge, which however does not extend to the
dorsal side. The head bears a small, truncated ulnar process, the surface of which is
somewhat smoothed, perhaps representing a contact with a fifth metacarpal. Like
metacarpal III, the surface immmediately distal to the head is very rugose, especially
in a line from the dorsal apophysis to the ulnar process, and over an area extending
40 mm. down the volar surface.

In the juvenile specimen the dorsal apophysis is more weakly developed, and
there is less rugosity. No facet for a fifth metacarpal can be distinguished.

Comparisons. Metacarpal IV of Schizotherium priscum has been figured by
Filhol (1893), and that of S. turgaicum by Borissiak (1921) and Belyaeva (1954).
In these, the head is less developed in a dorsovolar direction, owing to the absence
of the dorsal apophysis. The facet for metacarpal III resembles that of
C. rusingense, but faces more laterally, the uncinate facet occupying almost the
whole of the proximal surface of the bone. There is a facet for metacarpal V on
the ulnar side of the head.

In C. grande the dorsal apophysis is developed as in C. rusingense. The dorsal
and volar parts of the facet for metacarpal III are not so clearly differentiated,
and the ridge demarcating the unciform facet extends right across the head to the
dorsal surface. Metacarpal V is absent, and the ulnar process is more prominent
and less truncated than in C. rusingense.

Sesamoid.

F2079 is tentatively identified as a sesamoid of the manus of C. rusingense.
It is a curved, flattened bone, trapezoidal in volar view. Its medial edge is straight,
and bears a facet for articulation with the metacarpal keel. Its dorsal side is largely
occupied by the cylindrically concave part of the joint surface. The lateral edge
of its volar surface is raised to a ridge, forming the margin of the groove through
which passes the main flexor tendon of the digit. The greatest length of the bone
is 38 mm., the greatest width 19 mm.

Comparison. Although the sesamoids of chalicothere feet must have been com-
paratively large, they have been described only in the case of Morvopus elatus
(Holland & Peterson 1913). These differ from the specimen referred to C. rusingense
in possessing a volar process for ligamentary attachment near the distal end, and
in the frequent presence of a facet by which one sesamoid articulates with its partner.

Astragalus. (Text-fig. 13.)
The only example of this bone is MFW1208.55. It is not quite complete, part
of the distal surface having been broken away.

202 EAST AFRICAN CHALICOTHERES

S
oe,
SS

SIN
<3

SSS

=e.

\4l
»y
| of RS?
Yi
My

Sl Nae

A-E, right fourth metacarpal of Chalicotherium vusingense, from site R 106.

FIG. 12.
E, proximal view.

A, dorsal view ; B, volar view; c, ulnar view ; D, radial view ;
F-J, corresponding views of C. gvande, Paris specimen from Sansan. All x 4.

EAST AFRICAN CHALICOTHERES 203

In dorsal (anterior) view the astragalus is much broader than high: its
transverse diameter is 67 mm. and its height on the tibial side is 35-5 mm. The
trochlea is correspondingly reduced in height, with the keels only moderately
developed. Each keel subtends an angle of about 120°, but the fibular keel faces
less proximally than the tibial keel ; in dorsal view it reaches farther proximally
and distally. The neck of the astragalus, distally to the trochlea, is very short
(about 5 mm. high).

In volar (posterior) view may be seen a large, slightly concave, ectal facet on
the fibular side, separated by a groove from the small, rounded, slightly convex
sustentacular facet on the tibial side. The ectal facet extends more than half-way
across the astragalus. Proximally it meets the trochlea in an acute edge, and distally
on the fibular side it meets the small, flat distal calcaneal facet in a blunt angle.
The sustentacular facet is separated proximally from the tibial part of the trochlea
by a groove that leads to the astragalar foramina.

In distal view the fibular half of the astragalus is seen to be much narrower than
the tibial half : the dorsovolar diameter at the fibular keel is 24 mm., and at the
tibial keel it is 43 mm. Most of the distal surface is occupied by the navicular
facet, which extends from the tibial border more than half-way across the bone.
It is divided by a rounded convexity into two slightly concave areas, the larger one
being dorsal, and the smaller one tibial and volar. Owing to breakage the presence
of a cuboid facet cannot be determined ; it could not have been more than of limited
extent.

Fic. 13. Left astragali of Chalicotherium. Left, C. rusingense, MFW 1208.55, anterior
(dorsal), posterior and distal views. Centre, corresponding views of C. grande, Paris
specimen from Sansan. Right, corresponding views of C. goldfussi, from Pikermi,
BMNH. M11351. All x 4.

Key: c, cuboid facet ; e, ectal facet ; ”, navicular facet ; s, sustentacular facet.

204 EAST AFRICAN CHALICOTHERES

The tibial surface of the astragalus is much roughened, and near the trochlea
it is marked by a deep pit for a ligament.

Comparisons. The astragalus of Schizotherium turgaicum (Borissiak 1946,
Belyaeva 1954) is proportionately much higher than in C. rusingense, but the neck
is equally short, the greater height being shown in the trochlea. The trochlear
keels are more acute, and, on the volar side, the sustentacular and ectal facets are
more elongated proximo-distally. In distal view the astragali of the two species
are more similar, except that in C. rusingense the fibular part of the bone is narrower
relatively to the tibial part. There is no cuboid facet in S. turgaicum.

In C. grande the astragalus is lower than in C. rusingense, and has blunter trochlear
keels. The ectal facet is deeper, and does not extend so far towards the tibial side
(see Wegner 1913). In distal view the fibular part of the astragalus is narrowed
to the same extent as in C. rusingense. A cuboid contact is present in C. grande
in the form of a strip along the posterior edge of the navicular facet (figured by
Holland & Peterson 1913). The navicular facet is tilted towards the tibial side
to a more marked degree in C. grande than in C. rusingense, and, probably associated
with this, the tibial height of the astragalus is only 75% of the fibular height in
C. grande, compared with 87°% in C. rusingense.

Second Metatarsal. (Text-fig. 14 ; Table VIII.)

There are three examples of this bone. The best preserved is MFW1213.55.
F2071, which is somewhat weathered, is similar but a little longer. Sgr82.48 is
a small, juvenile specimen.

The proximal end is triangular in outline, with dorsal and volar processes, situated
towards the fibular side, and a tibial process. Most of the proximal surface is
occupied by the facet for the mesocuneiform, slightly concave in the tibio-fibular
direction. On the fibular side of this is the facet for the ectocuneiform, which in
MFW1213.55 is differentiated into dorsal and volar portions. The dorsal portion
faces in a fibular direction, and is separated from the mesocuneiform facet by a
sharp crest ; the volar portion faces proximally, and is separated from the meso-
cuneiform facet only by alow crest. In F2071 the dorsal portion is missing, perhaps
due to weathering. There is no entocuneiform facet. On the fibular side, below
the ectocuneiform facet, is an overhung facet for metatarsal III ; this apparently
does not extend to the extreme volar side of the bone. Below it again is a roughening
of the surface for ligamentary attachment. The dorsal process projects beyond
the fibular side of the bone and extends for a short distance down the shaft.

The middle of the shaft is oval in section, somewhat flattened in a dorsovolar
direction. The bone as a whole is short in comparison to its width: the total
length is 2-o—2-1 times the maximum width of the distal end.

The distal articulating surface is placed obliquely to the long axis, its tibial side
being more proximal than its fibular side. In F2071 its dorsal border is separated
from the shaft by a shallow groove, but this is not present in MFW1213.55.
Dorsally, the articulating surface projects beyond the level of the shaft, and forms
a smoothly convex area for the phalanx. The volar part of the articulation, for

EAST AFRICAN CHALICOTHERES 205

STW 4 15
nae po

C.grande

Fic. 14. Right second metatarsals of Chalicotherrum. C. vusingense, MFW 1213.55, in
dorsal, ulnar, volar, radial, proximal and distal views. C. pilgvimi, BMNH. M12168,
corresponding views. C. gvande, Paris specimen from Sansan, corresponding views.
All x 4.

206 EAST AFRICAN CHALICOTHERES

the sesamoids, is divided by a median keel which starts at the most distal end of
the bone. The groove on the tibial side of this keel is more deeply cut than the
groove on the fibular side. Proximally to the distal articulation, apophyses for
ligaments are developed on the lateral sides of the bone ; below each, but most
marked on the fibular side, is a pit.

Comparisons. In Schizotherium priscum (Filhol 1893) and S. turgaicum (Borissiak
1921) the second metatarsal is much more elongated (length/distal width 4-0 and
4:3 respectively, cf. 2:0-2-1 in C. rusingense). In C. pilgrima (BM.12168) it is
shortened to the same degree as in C. vusingense (2:1) but in C. grande it is somewhat
shorter (I-°7—1:9).

In proximal view the head is more compressed in a tibio-fibular direction in
Schizotherium than in Chalicotherrum. C. pilgrimi is very much like C. rusingense
in the shape of the proximal end, but in C. grande the head is trapezoidal rather
than triangular, owing to broadening on the volar side.

In S. turgaicum the ectocuneiform facet is divided into two. In the species of
Chalicotherium it is single, but C. rusingense and C. pilgrim: show more clearly
than C. grande a functional division between a more vertical dorsal part and a more
proximal volar part. In C. grande the crest separating the ectocuneiform and
mesocuneiform facets is blunt throughout its length, whereas in C. rusingense and
C. pilgrimi its dorsal half is acute.

TABLE VIII.

Measurements (mm.) of metatarsals of C. rusingense.

Second Third

MFW Ser.

1213°55 F2071 84:48 | F2076 R30 R648-47 Rot
Width of head : : ; 2, 26 21°5 25 23°5 175 23
Dorso-volar, head . 5 : 28 24°5 20 28 30°5 24 25
Minimum width, shaft ; : 20°5 23°5 15'5 23 22°5 15°5 19
Distal width, across articulation. 28 29 21 20'5 27 21°5 24
eng thi: ; : ; ; 58 58°5 50 69 62°5 58 57°5

The overhung facet for metatarsal III is double in S. turgaicum, single in the three
species of Chalicotherium.

At the middle of its length the shaft is more nearly circular in cross-section in
Schizotherium than in Chalicotherium where it is somewhat broadened. In C. grande
the shaft is broader in comparison with the distal width than in C. vusingense or
C. pilgrim.

Third metatarsal. (Text-fig. 15 ; Table VIII.)
Four specimens are identified as this bone, although they differ somewhat in
size and proportions. The longest specimen is F2076 (left). Another specimen

EAST AFRICAN CHALICOTHERES 207

(left) from R3o is of the same width but slightly shorter. 648.47 (left) and a
specimen from Ror (right) are smaller and more slender, and may be juvenile.

The ratio of length/distal width ranges from 2-2 to 2:6, and it is probable that
metatarsal III was slightly longer than metatarsal II of the same individual, though
of similar width. There is some variation in the shape of the section of the middle
of the shaft : thus in F2076 the transverse diameter slightly exceeds the dorsovolar
diameter, but in R648.47 the dorsovolar diameter is the greater, while the specimen
from R30 is nearly circular in section.

The proximal surface is roughly triangular or trapezoidal. It is inclined distally
towards the dorso-fibular apex, and is occupied by a very slightly convex facet for
the ectocuneiform. There is no distinct facet for the cuboid. The fibular edge,
which is nearly perpendicular to the straight dorsal edge, is slightly concave in
F2076, straight in the other specimens. The third edge, from the tibio-dorsal
apex to the fibulovolar apex, is convex. In all specimens the dorsovolar diameter
of the head is greater than the transverse diameter, but less markedly so in the
specimen from Ror than in the others.

Fic. 15. Right third metatarsals of Chalicotherium. Above, C. rvusingense, F 2076, in
dorsal, ulnar, proximal and distal views. Below, C. gvande, Paris specimen from Sansan,
corresponding views. All x 4.

208 EAST AFRICAN CHALICOTHERES

On the most proximal part of the fibular surface of the metatarsal are two facets
for articulation with metatarsal IV, slightly overhung by the fibular border of the
proximal surface. Each facet occupies the proximal part of a pit in the fibular
surface. The more dorsal facet is the larger ; it is somewhat concave, and faces
slightly in a volar direction. The volar facet is smaller and flatter.

The distal end is tilted towards the tibial side to a greater extent than in metatarsal
II. The fibular ligamentary apophysis is much better developed than its tibial
counterpart, whereas on metatarsal II they are more equal. The dorsovolar
diameter of the distal end is relatively greater than in metatarsal II, exceeding the
transverse diameter. The sesamoid articulation is accordingly more extensive than
the phalangeal articulation. The fibular sesamoid groove is more deeply incised
than on metatarsal II, though it remains shallower than the tibial groove.

Comparisons. This metatarsal is much shorter in comparison with its width than
in Schizotherium priscum (Filhol 1893) and S. turgaicum (Borissiak 1921). It is
much more like C. grande, though only the specimen from R30 agrees with that
species in proportions, the other specimens being relatively longer.

In Schizotherium metatarsal II is much more slender than metatarsal III, but in
C. grande the two metatarsals are of equal width, and this appears to be so also in
C. rusingense.

C. rusingense resembles Schizotherium in the proportions of the proximal end of
the bone ; in C. grande it is rather broader. In C. grande there is a distinct cuboid
facet, absent in C. rusingense and in Schizotherium. C. rusingense also agrees with
Schizotherium in the possession of two distinct facets for metatarsal IV ; in C. grande
the volar facet is apparently absent.

The distal ends of metatarsals II and III of C. grande differ in the same ways as
those of C. rusingense, but the differences are less marked.

Basal phalanges. (Table IX.)

Of 43 basal phalanges, 23 are referred to the manus, because of their larger size
and their resemblance to phalanges of the manus of C. grande. The 23 specimens
fall into three groups, regarded as representing digits II, III and IV.

Digit II of manus. (Text-fig. 16A). This type of phalanx is so identified from its
resemblance to the basal phalanx of B.M. M8638, a complete digit of C. grande,
including the metacarpal. It is broader proximally than distally. The proximal
border forms two lobes of which the radial is the more prominent. The facet for
the metacarpal occupies the proximal half of the dorsal surface of the bone. It is
concave, and faces very slightly proximally and radially. Its ulnar border is marked
by a prominent crest which reaches its greatest height at the disto-ulnar extremity
of the facet. Its radial border is lower, broadening out distally to form a crescent-
shaped flattened area that possibly marks the insertion of an extensor tendon.
Distally to the metacarpal facet the phalanx narrows to a waist, especially
conspicuous in lateral view. On the volar side there is a broad longitudinal concavity
between two marginal ridges. Each of these ridges is developed into a proximal
prominence, and about half-way along the bone there is a second, smaller prominence

EAST AFRICAN CHALICOTHERES 209

TABLE IX.

Measurements (mm.) of some phalanges, C. rusingense.

Manus II Manus III Manus IV Pes
Basal phalanges MFW
R450.47 R136a.49| R189.47 Ro45.47| R136.49 F2074 | 1214.55 R452.47
Ulnar length 56°5 49'3 60-2 57 63 56-2 42°4 39
Radial length 59 50 58-3 54°5 59°7 51:2 40°2 30°5
Length of metapo-
dial articulation 25°7 20°8 25:2 21°5 27°5 25°7 Da 20:2

Length distal to
metapodial arti-

culation 22 20°5 23°1 23°3 24 19'7 15 13°5
Proximal width 34 31 36°5 33 39°5 33°5 30°5 27°4
Distal width 23 22°5 25°1 22B 27 24:2 23 19°8
Thickness 25°5 23°6 26:7 22°90 20°5 23°2 19°5 19°4

Manus Pes
Middle phalanges MFW
R136b.49 R757.47 R748.50 | 1217.55 R233.51 R844.48
Maximum length . : ; F 45 39 38 30 28 25°5
Proximal width . : : : 27°5 21 24 21°5 18:5 18°5
Width across trochlea . A ; 22 15'5 19 18°5 15'5 14
Height of trochlea. : ; : 37 28 30 24 22 21°5
Manus Pes
Ungual phalanges
R136c.49 R134.49 R160.49 Rg22.47

Maximum length . 3 c . 96 — — 64e
Length of base. : : : 66 60 48 41
Height of articulation . ; : 30 26e 23 21
Height at cleft : ; : ‘ 44 43 40 32
Width of base ; : : 6 25 20°5 25 20
Width of articulation . j : 22°5 18 19 16

(intermediate volar tubercle). Distally, the marginal ridges merge into the keels
that form the edges of the articulation for the middle phalanx. This articulation,
which occupies the distovolar part of the bone, is in principle a trochlea, with
median groove and lateral keels. However, it usually shows an incomplete subdi-
vision into a distal part and a volar part. The bottom of the groove in passing
from one part to the other forms a slight but distinct angulation ; the lateral keels
diverge in the distal part, but are parallel in the volar part ; the joint surfaces on
the sides of the groove, instead of being evenly curved, are incompletely differentiated
into two areas corresponding to the two parts of the groove and keels. The articula-
tion is not symmetrically placed in relation to the phalanx as a whole, but is arranged

210 EAST AFRICAN CHALICOTHERES

Fic. 16. Basal phalanges. a-c, Chalicotherium rusingense. A, R 450.47 (left manus),
dorsal, radial and distal views. 8B, unnumbered specimen from site Rs 91 (right manus,
reversed), dorsal, radial and distal views. c, unnumbered specimen from site Rs 30
(left manus), dorsal and radial views, and F 2075 (right manus, reversed), distal view.
D, Schizotherium priscum, three phalanges from Paris Museum, dorsal and lateral views.
rE, C. gvande, three types of basal phalanx of the manus, Paris Museum, in dorsal view.
All x 4.

EAST AFRICAN CHALICOTHERES ya

so that its most dorsal end is displaced towards the ulnar side and its volar end
towards the radial side. The lateral surfaces of the phalanx are marked by proximal
and distal roughenings for ligaments. The ulnar surface is deeper and flatter than
the radial surface, which is more convex and less distinctly marked off from the
dorsal surface.

There are 8 examples of this bone, ranging in ulnar length from 44-3 to 56-5 mm.
(mean 50-4), in radial length from 44-3 to 59 mm. (mean 52:4).

Digit III of manus. (Text-fig. 168.) This phalanx averages rather longer and
narrower than that of digit II. The metacarpal facet occupies less than half the
dorsal surface ; the shaft distal to this facet is relatively longer and narrower, and
the distal trochlea is also relatively narrower. The flattened area on the radial
edge of the metacarpal facet is less conspicuous. The lobes of the proximal end are
more equal, the ulnar lobe exceeding the radial lobe slightly. The intermediate
volar tubercles are distal to the metacarpal facet.

Seven complete specimens range in ulnar length from 50-2 to 60:2 mm. (mean
57°3). There is also a larger specimen of which the ulnar length must have been
about 68 mm.

This phalanx is identified as belonging to the third digit because it is the longest
and most symmetrical of the three types.

Digit IV of manus. (Text-fig. 16c.) -In this type the ulnar lobe of the proximal
border is much more prominent than the radial lobe. It is shorter than the phalanx
of digit III, and resembles that of digit Il in length. The metacarpal facet occupies
rather more than half the dorsal length, and the intermediate volar tubercles are
placed opposite the distal part of the facet, as in digit II. This phalanx differs from
that of digit II in being more stoutly constructed, in lacking a waist, and in the lack
of a conspicuous area of flattening on the radial margin of the metacarpal facet, as
well as in the different shape of the proximal border.

There are 7 examples of this bone, ranging in ulnar length from 46-5 to 65 mm.
(mean 555).

Pes. (Text-fig. 17a—c.) The basal phalanges of the pes are smaller than those of
the manus (ulnar length of 10 complete specimens, 37—44:3 mm., mean 40-8). The
metatarsal facet faces more dorsally, and always occupies more than half of the
dorsal surface. Intermediate volar tubercles are usually absent. The phalanges
of the three digits of the pes appear to differ in much the same way as those of the
manus, but to a smaller degree.

Two specimens, one from Rusinga (unnumbered) and one from Songhor (Sgr 32°47),
though small (ulnar length 35-7 and 35:3 mm. respectively) are more slender than
specimens referred to the pes. They are probably juvenile specimens from the
manus.

Comparisons. The basal phalanges of the manus of C. grande are from one-third
to one-half larger than those of C. rusingense. There are some differences in
proportions : the proximal width is relatively greater, and the metacarpal facet
occupies a greater proportion of the dorsal surface than in most specimens of

EAST AFRICAN CHALICOTHERES

N
H
nN

Fic. 17. Basal phalanges of the pes. a-—c, Chalicotherium rusingense. A, R 452.47. B,
R 281.51. c, Rusinga, no data. vb, two phalanges of C. grande, Paris Museum. All
x 4.

C. rusingense. The intermediate volar tubercles are very weakly developed. As in
C. rusingense, phalanges of the pes are much smaller than those of the manus.

The phalanges of the manus of C. grande fall into three groups, presumably
corresponding to the three digits, as in C. rusingense. (Text-fig. 16£.) The
differences between them are not so great, however ; for example, phalanges referred
to digit III are less obviously elongated, in comparison with those of digits II and
IV, than in C. rusingense. Unfortunately, the articulated left manus described and
figured by Gervais (1877) and by Holland & Peterson (1913) cannot be used to
identify the phalanges of the different digits, for the digits appear to have been
reconstituted artificially : the basal phalanx of digit IV belongs more probably to
digit III of the right side ; that of digit II seems to belong to digit IV, and that of
digit III to digit IT.

Two basal phalanges may tentatively be referred to C. pilgrimi : B.M. 12170
and 12172 (Forster-Cooper 1920). From its symmetry, 12172 may be interpreted
as from digit III of the manus. It is a little shorter than most specimens of
C. rusingense of this type, agreeing in length more with those of digits II and IV.
It is broader than any of the phalanges of C. rusingense. Its metacarpal facet
occupies rather more than half of the dorsal surface, as in C. grande. Intermediate
volar tubercles are well-developed. 12170 appears to belong to digit II, as the
metacarpal facet extends more proximally on the radial side than on the ulnar side.
It is somewhat larger than in C. rusingense, and its metacarpal facet is more
extensive.

A phalanx of the pes, referred to C. wetzleri by Viret (1929) is very similar in size
and shape to specimens of C. vusingense. It has an intermediate volar tubercle,
like some of these.

EAST AFRICAN CHALICOTHERES 213

Several basal phalanges of Schizotherium turgaicum are figured by Belyaeva
(1953, pl. 3), and five specimens of S. friscum were examined in Paris (Text-fig. 16D).
In each species the phalanges show a variety of size and form, but they cannot be
allocated to the different digits on the same basis as in Chalicotherium. Filhol’s
(1893) drawings of the metapodials of S. priscum indicate that the phalanges of the
pes are probably larger than those of the manus, at least on digits III and IV, as in
Grangeria (Colbert 1934) : the largest phalanx in Paris is about as wide as the distal
end of the third metatarsal. Most specimens resemble in general proportions those
of digit III of the manus of C. rusingense, but they may be distinguished by the much
more proximal orientation of the metacarpal (metatarsal) facet, which occupies less
than one-third of the dorsal surface. In side view the distal trochlear keels are less
convex, permitting less rotation of the middle phalanx. Intermediate volar
tubercles are frequently present, as in C. rusingense. In a few specimens (one of
S. priscum and two of S. turgaicum) the metacarpal facet faces more dorsally and
occupies nearly half the dorsal surface, as in C. rusingense. In Moropus and
Phyllotillon a similar dorsal orientation of the facet distinguishes the basal phalanx
of digit II of the manus, and this may well have been true also of Schizotherium.

Middle Phalanges. (Text-fig. 18 ; Table IX.)
There are 28 middle phalanges in the collection. They vary in size: the larger
ones probably belong to the manus and the smaller ones to the pes. The small

Tic. 18. Middle phalanges. Left, Chalicotherium rusingense, R 136.49, in lateral, dorsal
and proximal views. Centre, C. vusingense, from site Rs 38. Right, Schizotherium
priscum, Paris Museum. All x 4.

214 EAST AFRICAN CHALICOTHERES

specimens, making up about half of the series, are more alike in size and shape than
the large specimens, and it appears that the middle phalanges of the different digits
of the manus are less uniform than those of the pes. The most compressed
specimens, with narrow proximal and distal joint surfaces, probably belong to digit
III of the manus, and the small phalanges, supposedly from the pes, are compara-
tively broad in relation to their length and height.

The phalanges are short, laterally compressed bones. The proximal surface is
occupied by the articulation for the basal phalanx. This consists of a pair of lateral
concave joint surfaces separated by a median keel. The keel runs from a pointed
dorsal process, which in many specimens projects beyond the general dorsal surface
of the phalanx, to a broader, truncated or slightly emarginate volar process. The
volar part of the keel broadens out, the volar parts of the articulatory facets diverg-
ing from each other. The dorsal and volar parts of the keel often meet in a more or
less distinct angle, corresponding to the angle in the groove of the distal articulation
of the basal phalanx. In some specimens the lateral joint surfaces also show signs
of a division into a dorsal part, facing proximally, and a volar part, facing more
dorsally. The articulation for the basal phalanx is not symmetrically placed in
relation to the median plane of the bone, but faces slightly towards the ulnar
(fibular) side. The distal end of the phalanx is occupied by the articulation for the
ungual phalanx. It has the form of a trochlea, consisting of a median groove and
prominent lateral keels, semicircular in lateral view. Dorsally the keels are parallel,
but towards the volar side they diverge slightly and the groove between them
becomes shallower. The lateral surfaces of the phalanx are flattened, except at the
distal margin of the proximal articulation, which projects laterally ; near the middle
of each lateral surface is a pit for hgamentary attachment.

Comparisons. Except for their larger size, the middle phalanges of C. grande
are indistinguishable from those of C. vusingense. In C. grande the phalanges of the
pes are smaller and proportionately broader than those of the manus, as was postu-
lated for C. rusingense.

A middle phalanx of Schizotheriwm priscum in Paris fits the larger basal phalanges.
It compares in size with some phalanges of the manus of C. vusingense, but is
relatively broader. Some middle phalanges of S. turgaicum described by Belyaeva
(1954) are smaller than any of C. rusingense, and relatively broader. In the Paris
specimen, the proximal articulation as a whole faces more dorsally than in
C. rusingense, the volar part being more extensive and the dorsal part reduced.
The distal trochlea faces more ventrally, its keels are more widely separated at their
dorsal ends, and the groove between them is much shallower. S. turgaicum appears
to possess the same characters. The middle phalanges of Schizotherium thus
approach those of Phyllotillon and Moropus.

Ungual phalanges. (Text-fig. 19 ; Table IX.)

Seventeen ungual phalanges in the collection all have a similar structure, though
they differ in size and proportions.

The phalanx is approximately triangular in side view, with a curved dorsal border
which extends proximally to form a prominent dorsal process (preserved intact only

EAST AFRICAN CHALICOTHERES 215

in R1r36.42, and almost complete in Rg22.47). The articulation for the middle
phalanx occupies most of the proximal surface and extends along the lower side of
the dorsal process. It is curved in an arc of about 100°, and consists of a pair of
elongated joint facets separated by a median keel. Below the articulation is a
median pit, probably for the flexor ligament, and on either side of this a foramen
through which blood vessels passed to the bed of the claw. The terminal part of
the phalanx is split by a deep cleft, extending back more than halfway along the
volar and dorsal surfaces. The volar surface proximally to the cleft 1s swollen into a
rounded boss. The lateral surfaces of the phalanx are flattened and rather rugose.
The bone is not quite symmetrical : in relation to the plane of the cleft the dorsal
process is directed slightly towards the ulnar (fibular) side. The articulation is
also asymmetrically arranged: its dorsal end (on the dorsal process) is ulnar
(fibular) to its volar end. The volar boss is displaced a little towards the ulnar
(fibular) side.

iP SD °<

Fic. 19. Ungual phalanges. a, Chalicothevium rusingense, R 136.49, lateral, volar and
proximal views. B, C. vusingense, R 922.47, lateral and volar views. c, Three phalanges
of Schizotherium priscum, Paris Museum. All x 4.

216 EAST AFRICAN CHALICOTHERES

The phalanges fall into two groups, which are probably to be referred to the manus
and pes. Those of the pes are broader in proportion to length and height, and are
more deeply cut by the claw cleft, the dorsal limit of this being perpendicularly above
the volar boss. The distinction is particularly clear in the region of the volar boss :
in the manus the horizontal length of the boss, measured from the end of the claw
cleft, is about the same as the width of the phalanx (index 80-105) : in the pes it
averages a little more than half the width (index, 47-70). The phalanges of the
manus are on the average higher than those of the pes (height at volar boss : manus
38-52 mm., pes 32-42 mm.), and also longer in volar length (manus 50-66 mm.,
pes 41-52 mm.), but the ranges of width are similar. The radius of curvature of the
proximal articulation is greater in the manus than in the pes. It has not been
possible to allocate phalanges to individual digits with any certainty. It is likely
that the largest phalanges belonged to digit II of the manus (e.g. R736.50 and
R136.42) and pes (e.g. R497.42), but the preponderance of the claw on this digit of
the manus was certainly much less than in Moropus.

Comparisons. There are four specimens of ungual phalanges of Schizother1um
priscum in Paris, including a large specimen which compares in measurements with
Ancylotherium gaudryi Filhol (1880). They are all rather broad, comparing in
length/width relations with the phalanges of the pes of C. vusingense. Their
height/width indices are, however, much less than in any specimen of C. vusingense,
and there are various differences in detail : the dorsal process is less developed ;
the proximal articulation has a less prominent median keel, and its curvature is
less ; the volar surface is flattened and is separated from the lateral surfaces by sharp
edges. An ungual phalanx of S. turgaicum figured by Belyaeva (1954) shows similar
characters, but is even lower and broader. The largest specimen of S. priscum
approximates in size to the smallest specimens of C. rusingense.

The ungual phalanges of C. grande are so similar to those of C. vusingense that it
is possible to distinguish them only by size.

The Digit as a Whole. (Text-fig. 20.)

The second metatarsal MFW1214.55 fits the basal phalanx MFW1213.55 so well
that they probably belong to the same individual. A satisfactory, but not perfect
fit was found between the third metatarsal from Roi and the basal phalanx F2082.
When the basal phalanx was placed so that the dorsal border of its articulating
facet coincided with the dorsal border of the facet on the metatarsal, the angle
between the dorsal surfaces of the two bones was about 72°. As in other chali-
cotheres therefore, the basal phalanx is capable of considerable hyperextension.

In this position, no appreciable rotation of the phalanx is possible round its own
axis, but lateral sliding would result in some abduction or adduction of the digits.
There is no evidence of the notches noticed by Matthew (1929) on the margin of the
metacarpal facet of the basal phalanx of digit II in Movopus, and interpreted by
him to imply two alternative positions of the digit. It is possible however that
his “lateral notch’ corresponds to the flattened area on the radial margin of the
facet in C. rusingense, interpreted here as the insertion of an extensor ligament.

EAST AFRICAN CHALICOTHERES 217

In maximum flexion the dorsal angle between the phalanx and the metatarsal
opens out to no more than about 110°. Rotation beyond this point is prevented
by the median keel on the metatarsal, which meets the notch in the proximal border
of the phalanx. Presumably the more posterior part of the metatarsal joint surface
was occupied by the sesamoid bones, which would remain in contact with the proxi-
mal end of the phalanx throughout the movement, being tied to it by a ligament,
equivalent to the middle sesamoidal ligament of the horse.

Although the distal ends of the metacarpals of C. rusingense are not known, the
similarity of the basal phalanges of the manus to those of the pes is such that con-
siderations based on the pes may be taken to apply also to the manus. This is
certainly true of C. grande.

Fic. 20. Reconstructed toes. a-c, Chalicotherium rusingense. A, from the manus,
walking position ; 8B, from the pes, walking position ; c, from the manus, clinging
position. D, Schizotherium priscum, walking position. E, Plagiolophus annectens,
walking position.

The joint between the basal and middle phalanges shows a partial differentiation
into dorsal and volar portions, representing the areas of greatest pressure during
extension and flexion respectively. By fitting phalanges together it may be seen
that even in maximum extension the middle phalanx turns down on the basal
phalanx ; the median axis of the middle phalanx makes an angle of 10-15° with

218 EAST AFRICAN CHALICOTHERES

the long axis of the basal phalanx. The rotation from maximum extension to
maximum flexion is 30—40°, so that at maximum flexion the angle between the two
phalanges is about 45°.

Movement between the middle phalanx and the ungual phalanx is greater : the
angle of rotation appears to be about 60°. In maximum extension, the volar
surface of the ungual phalanx lies approximately parallel to the median horizontal
plane of the middle phalanx, but at a lower level, leaving space beneath the middle
phalanx for the flexor tendon. The total amount of bending in the digit itself
would be rather more than a right angle, to which must be added 40° or so at the
metapodial-phalangeal joint.

When walking, the weight must have been received on the proximal ends of the
basal phalanges, and presumably also on the sesamoids ; it is likely that a plantar
pad existed in this region. The toes themselves did not play any part in supporting
the animal. Reconstruction of complete digits shows that the claw probably
rested on the ground, the toe being extended but forming an arch. By extreme
extension the claw could be raised a little, which would be necessary when the
animal was walking over rough ground. This is a much less specialized condition
than that found in Ancylotherium pentelicum by Schaub (1943), in which the toes
were held back against the dorsal sides of the metacarpals. Maximum hyper-
extension of the digit in C. vusingense would seem to be accounted for by pressure
of the claw against the ground, aided by the main extensor ligament attached to the
dorsal process of the ungual phalanx, but in Ancylother1um Schaub found it necessary
to postulate the existence of elastic ligaments.

In Schizotherium the position of the proximal articulating surface of the basal
phalanx shows that the degree of hyperextension must have been much less than in
Chalicotherium ; it is doubtful whether the distal end of the phalanx could be raised
above the proximal end. The known middle and ungual phalanges appear to
indicate a digit that was straight, inclined downwards at a small angle, and placed
so that the flattened volar surface of the ungual phalanx rested on the ground.
The elevation of the proximal part of the basal phalanx above the ground seems to
have been small, and much of the weight of the animal might well have been sup-
ported by a pad at the base of the digit ; nevertheless, the ungual phalanx must
have taken some of the weight, and Schizotherium was digitigrade rather than
“metacarpograde”’. Gyvangeria again seems to have had a digitigrade foot, though
its ungual phalanges are unknown. Some degree of hyperextension at the
metapodial-phalangeal joint is found in all perissodactyls, and the chalicotheres
seem to have exaggerated this, first becoming digitigrade by modification of the
distal end of the metapodial and probably receiving part of the weight on a pad
in this region ; then the whole weight was received by the pad, thus permitting a
higher degree of specialisation of the claws.

In C. rusingense and C. grande, if the basal phalanx is placed so that its most
volar surface is horizontal in the transverse direction, the keels for articulation
with the middle phalanx are approximately vertical, but the metatarsal is inclined
so that its proximal end is medial to its distal end. This is probably the natural

EAST AFRICAN CHALICOTHERES 219

position, for the greater length of the third metatarsal is such as to bring its basal
phalanx to the same level as that of the second digit. In C. grande the metatarsals
increase in length from the second to the fourth. If they were held vertically, only
the fourth digit would reach the ground, as Matthew (1929) pointed out.

There are objections to believing that Chalicotherium walked on the outside of
its foot. The fourth metatarsal and metacarpal are no stouter than the others ;
in fact in the manus the second metacarpal is the stoutest. In Movopus and
Ancylotherium, again, the second metatarsal is shorter but stouter than the third,
though unlike Chalicotherium the fourth is shorter than the third. Schaub con-
cluded that in Ancylotheriwm the weight was taken by the radial digits (II and III).
It seems highly probable therefore that in Chalicotherium, as well as in Ancylotherium,
the second digit touched the ground. This must imply an inclination of the whole
manus or pes towards the radial or tibial side. If the feet were orientated in a
normal manner, with their dorsal sides facing forwards, the limbs would have to
be spread out far laterally. It would be mechanically more efficient to bring the
feet beneath the body by rotating them so that the toes pointed somewhat inwards,
the shortest metapodial being then the most posterior, and it is suggested that this
was the position in which Chalicotherium walked.

In maximum hyperextension the basal phalanx does not lie in line with the
metapodial, but is turned so that its distal end is more lateral. The plane of rotation
at the metapodial-phalangeal joint is inclined, so that the two bones come to lie in
the same vertical plane only in maximum flexion. The two interphalangeal joints
are not in the same plane ; if the joint between the basal and middle phalanges is
considered as vertical, the joint between the middle and ungual phalanges is inclined
so that its dorsal side is more lateral. The effect is that when the digit is extended it
is curved towards the lateral side, but as it is flexed the claw is moved medially, till
it lies parallel to and almost in line with the basal phalanx. Thus in the walking
position the toes would point forwards, in spite of the medial rotation of the feet,
while when the toe is flexed in order to use the claw, the metapodial, phalanges and
claw are nearly in the same plane.

The dorsal position of the metacarpal facet on the basal phalanx of digit II of the
manus in Phyllotillon, Moropus and probably in Schizotherium, may be related to the
enlargement of the claw of that digit. If the claw rested on the ground in walking,
the degree of hyperextension that would be required at the metapodial-phalangeal
joint would be greater the larger the claw.

Schaub suggests that the elevation of the claws in Ancylotherium was an adapta-
tion to avoid blunting when walking on hard ground. The lack of this adaptation
in Chalicotherium would imply that the animal frequented ground too soft to cause
serious damage to the claws. This accords with the view of Abel (1920) that
Chalicotherium (“ Macrotherium’’) was an inhabitant of forest, where the ground
would be covered with litter, while Ancylotherium (‘ Chalicotherium’’) preferred
more open country (savannah).

The shortness and stoutness of metacarpal II might be interpreted as an adaptation
to clinging to tree-trunks in the manner postulated by Borissiak (1945) : the more

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222 EAST AFRICAN CHALICOTHERES

lateral digits would extend round the sides of the trunk and their greater length
would be advantageous, but most of the pressure would be exerted by the second
digit, which would be applied most perpendicularly to the surface of the trunk. In
the pes, the short second digit might be associated with a straddling of the legs to
give a firmer support, the claws presumably being dug into the ground.

Proportionate Sizes of Teeth and Feet.

In the absence of associated remains it is possible to make only a very rough
estimate of the size of the feet in comparison with the teeth. The method used was
to divide measurements of the bones of the feet by the mean length of M,. Where
more than one specimen of a bone is known, the largest specimen is compared with
the largest specimen of M, and the smallest with the smallest specimen of M,,
obviously juvenile specimens being neglected. This was done also for specimens of
C. grande from Sansan, for Schizotherium turgaicum and for S. priscum. (Table X.)

C. rusingense differs only slightly from C. grande. The greatest difference is its
proportionately larger scaphoid, which suggests that the single specimen of this
bone comes from an unusually large individual. Otherwise the differences are
hardly significant : the head of the fourth metacarpal is smaller, the basal phalanx
of the third digit of the manus is longer and narrower, the metatarsals are longer,
and the ungual phalanges of the pes are broader.

Both species of Chalicotherium differ considerably from Schizotherium. The
metacarpals are relatively broader, as is the manus as a whole. In C. grande
metacarpals II and III are somewhat shorter than in S. priscum, but metacarpal IV
is approximately of the same relative length. The pes of C. grvande is much broader
than that of S. priscum. In both species of Chalicotherium the astragalus is
proportionately broader and thicker than in S. turgaicum, but of similar relative
height, and the metatarsals are much shorter than in S. priscum. The phalanges of
the manus are proportionately much larger in all dimensions in Chalicotherium than
in Schizotherium.

RELATIONSHIPS.

In the foregoing description C. vusingense has been compared mainly with
C. grande, the best-known member of the Chalicotheriinae, and with species of
Schizotherium (S. priscum and S. turgaicum), the most primitive genus of Schizothe-
riinae. It shows resemblances to both these forms, but the resemblances to
C. grande are of greater taxonomic value, whereas those to Schizotherium are primitive
characters inherited from the common ancestor of Chalicotherium and Schizotherium,
perhaps in the Lower Oligocene.

C. rusingense is Close to C. grande in (1) the upper molar pattern, (2) the loss of the
hypoconulid of Ms, (3) the reduction of the scaphoid-magnum contact, (4) characters
of the head of metacarpals III and IV, (5) the broad, short metatarsals, those of
digits II and III being equal in width, (6) the astragalus, which is reduced in height,
and also reduced in thickness in the fibular half, (7) the greater size of the phalanges
of the manus as compared with those of the pes, (8) the form of the articulating facets

EAST AFRICAN CHALICOTHERES 223

on the phalanges, associated with the development of a metacarpograde stance, and
(9) the ungual phalanges, which are narrower and less hoof-like than in Schizotherium.

At the same time C. vusingense is more primitive than C. grande in several respects
in which it approaches Schizotheriwm : (1) the smaller size, (2) some features of the
upper molar pattern—the protocone is frequently connected to the protoconule by a
ridge, the ridge on the buccal slope of the paracone is sharper, and the accessory rib
in the postfossette is frequently present, (3) the presence in most specimens of a
metastylid on the lower molars, (4) the smaller degree of reduction of the premolars,
(5) the greater elongation of the anterior part of the jaws, (6) the astragalus, in which
the trochlea is higher and the navicular facet is less tilted towards the tibial side.
(7) the less thickened metatarsals, (8) the absence of a distinct cuboid facet on
metatarsal III, and the presence of two separate facets for articulation with metatar-
sal IV, (9) the longer basal phalanges, especially on digit III of the manus, and (10)
the better development of intermediate volar tubercles on the basal phalanges.

C. pilgrimi agrees with C. rusingense in size, in the presence of a metastylid on the
lower molars, and in the characters of metatarsal II, but the upper molars of
C. pilgyimt are more primitive in that the paracone and metacone have not receded
so far from the buccal edge of the tooth. C. wetzleri agrees with C. rusingense in the
metastylid, and perhaps in the elongation of the snout and characters of the
phalanges. C. salinum, though much nearer to C. grande, shows some primitive
features in the sharpness of the buccal paracone crest and the retention of the
protocone-protoconule crest.

C. rusingense must therefore be regarded as a persistently primitive form not
closely related to other species of the genus. Its interest lies mainly in the light it
throws on the evolutionary changes involved in the derivation of the Chalicotheriinae
from a form close to Schizotherium.

Subfamily SCHIZOTHERIINAE
ANCYLOTHERIUM AND RELATED GENERA

Ancylotherium pentelicum (Gaudry & Lartet 1856) is a characteristic member of
the Pontian fauna of Pikermi, Samos and other localities in S.E. Europe, extending
to Maragha in Iran (de Mecquenem 1924). Thenius (1953) pointed out the re-
semblances between this species and Metaschizotherium fraast von Koenigswald
(1932), from the Upper Miocene of Germany and France, and proposed to include
the genus Metaschizotherium in Ancylotherium. Viret (1949) had previously con-
sidered M. fraasi to be almost identical with Phyllotillon naricus (Pilgrim 1908, 1910)
from the Lower Miocene of Baluchistan. It is also necessary to consider Phyllotillon
betpakdalensis (Flerov 1938), from the Upper Oligocene of Kazakhstan, which has
been described in great detail by Borissiak (1946).

The upper molars of A. pentelicum (Thenius 1953, Wagner 1857), M. fraasi
(Fraas 1870, Depéret 1892, von Koenigswald 1932), P. naricus (Pilgrim 1912,
Forster Cooper 1920) and P. betpakdalensis (Borissiak 1946) are so much alike
that the relationship of the species cannot be doubted. The molars of P. naricus

224 EAST AFRICAN CHALICOTHERES

show a considerable range of size (length of M? 40-48 mm.; length of M? 40-49 mm.):
the specimens identified as milk-molars by Pilgrim (1912, pl. 12, fig. 3) are small
examples of permanent molars. M. fraasi falls within the lower part of the size
range of P. naricus. It is doubtful whether M. bavaricum von Koenigswald (1932)
is specifically distinct from M. fraast. P. betpakdalensis is very variable and reaches
a larger size (length of M? 42-60 mm.). <A. fentelicum equals or slightly exceeds
the largest specimens of P. betbakdalensis. According to Thenius (1953) A. penteli-
cum differs from M. fraasz in the more elevated ectoloph and the weaker cingulum,
but the differences do not appear to be great. P. betpakdalensis stands apart in
(1) the stronger development of the buccal cingulum, (2) the straighter protoloph,
which runs almost directly to the tip of the protocone, instead of bending sharply
to pass up the anterior slope of the protocone, and (3) the strong development of
the cingulum round the base of the hypocone in some specimens of M3, withthe
formation of additional cingular cusps in that region (Borissiak regarded the hypocone
as a metaconule, and the cingular cusps as representing the hypocone).

There are some differences in the upper premolars. In P. naricus the deuterocone
on P? and P* is conical, with a convex buccal slope ; it is connected to the ectoloph
by a protoloph anda metaloph. In P. betpakdalensis the buccal slope of the deutero-
cone forms a more definite ridge. In A. pentelicum the deuterocone is crescentic,
apparently with a flattened buccal slope. A specimen of P* referred to M. bavaricum
by von Koenigswald (1932) and a similar tooth figured by Roger (1885) are partly
molarized : a small crest branches off from the metaloph to join the posterior
cingulum.

The lower molars of P. naricus, P. bethakdalensis and M. fraasi are very similar
in structure. The only lower molar of A. pentelicum that has been figured is M, in
a juvenile mandible (Dietrich 1928). A strongly developed metastylid is charac-
teristic of the group.

Specimens and casts show that in P. naricus and P. betpakdalensis the infraorbital
foramen is situated above M?, as in Moropus, whereas in Chalicotherium and in
Schizotherium priscum it is farther forward, above M!. The mandibles of P. naricus,
P. betpakdalensis and A. pentelicum (Falconer 1868) are distinguished from those of
Chalicotherium in the short symphysis, which does not extend back as far as Py.
According to Falconer (1868), and Major (1894), A. pentelicum lacks the lower canine
and incisors, but a specimen of P. naricus shows traces of alveoli at the anterior
end of the mandible. A juvenile mandible from St. Gérand-le-Puy, described by
Filhol (1879) as Chalicotherium modicum, and now in Paris, has a short symphysis
like P. naricus and may be referred to the genus Phyllotillon. At the anterior end
it shows a large alveolus, probably for a lower canine.

The lower end of the humerus of P. betpakdalensis differs from A. pentelicum
and from Morvopus in the shape of the articulatory surfaces, but resembles
Schizotherium turgaicum. The radius and ulna are more slender than in A. pentelicum;
the radius is less flattened at its distal end, and fusion with the ulna is less complete.

Except for a lunate of M. fraasi described by Rinnert (1956), the carpals are
known only in P. betpakdalensis (Borissiak 1946) and A. pentelicum (Schaub 1943).

EAST AFRICAN CHALICOTHERES 225

Those of P. betpakdalensis differ from A. pentelicum mainly in a primitive direction :
for example, the scaphoid is comparatively deep, with a well developed distal
process as in Moropus ; the lunate has a prominent volar process ; the trapezoid
and unciform are relatively narrow and deep, and the carpus as a whole is deeper,
with more oblique articulatory facets. The lunate of M. fraasi resembles that of
A. pentelicum.

P. betpakdalensis has a fifth digit on the manus, lost in A. pentelicum. Meta-
carpals II-IV are less flattened than in A. pentelicum, and do not show the dorsal
concavity characteristic of that species.

The astragalus of P. betpakdalensis is higher than in A. pentelicum, and differs in
the possession of a cuboid facet. That of M. fraasz (von Koenigswald 1932, Thenius
1953, Rinnert 1956) resembles A. pentelicum. In all three species the ectal facet
is deeply concave, in contrast with the much shallower facet of Chalicotherium.
The calcaneum is similar in the three species. In P. betpakdalensis the cuboid,
navicular and ectocuneiform are much less flattened than in A. fentelicum ; the
cuboid of M. fraasi (Rinnert 1956) resembles that of A. pentelicum.

The metatarsals of P. betpakdalensis are much more slender than those of
A. pentelicum. Phalanges of all four species are known : some of the phalanges
described by Forster Cooper (1920) from the Bugti Beds are almost certainly those
of P. naricus. Except in P. betpakdalensis the basal and middle phalanges of
digit II normally unite. In A. pentelieum the basal phalanges are more flattened
at the distal end than in the other species, so that the surface for articulation with
the middle phalanx makes a smaller angle with the long axis of the bone. The
known basal phalanges of P. betpakdalensis are much smaller than those of
A. pentelicum (length 55-70 mm. compared with g1-114 mm.), although there is
less discrepancy in the teeth ; it is possible therefore that the toes of P. betpakdalensis
were proportionately smaller, as in Schizotherium.

This comparison shows that P. betpakdalensis stands apart from the other species.
In several respects it is much more primitive than A. pentelicum, as would be
expected from its earlier age, but it shows some specializations, such as the cuboid-
astragalus contact and the large size, which exclude it from the ancestry of the later
species. I therefore propose to make it the type species of a new genus.

Genus BORISSIAKIA nov.

DiaGnosis. Schizotheriine chalicotheres of large size, in which the protoloph
runs directly to the tip of the protocone, the scaphoid and lunate resemble those of
Moropus, there are four digits on the manus, and the astragalus articulates with
the cuboid.

Type and only known species, Moropus betpakdalensis Flerov (1938).

Genus PHYLLOTILLON Pilgrim, 1910

Phyllotillon naricus and Metaschizotherium fraasi are very close, and may be
conspecific as Viret (1949) suggested. Metaschizotherium therefore becomes a
synonym of Phyllotillon. This genus first appears as a small unnamed species in the

226 EAST AFRICAN CHALICOTHERES

Upper Oligocene of St. Gérand-le-Puy (Filhol 1879), and thus coexisted with
Borissiakia betpakdalensis. Phyllotillon is probably the ancestor of Ancylotherium,
from which it may be distinguished by primitive characters: (1) teeth present
at the anterior end of the mandible (in Ancylotheriwm lower incisors and
canine have disappeared) ; (2) distal ends of basal phalanges of digits III and IV
less flattened. Unfortunately the skeleton is poorly known.

Genus ANCYLOTHERIUM Gaudry, 1862
Ancylotherium hennigi (Dietrich)

Text-figs. 2IA—D, 22A—D, 23A—D, 24, 25A, B, 260A, B.

1923 Chalicothere, Andrews, p. 696.

1926 Chalicotheridae, gen. et sp. indet., Hopwood, p. 19, text-fig. 1.

1942 Metaschizotherium hennigi Dietrich, p. 105, pl. 4, figs. 33, 37, pl. 12, figs. 78-80, 83.
1943 Metaschizotherium hennigi Dietrich ; Schaub, pp. 19, 25.

1950 Metaschizother1um transvaalensis George, p. 241, text-figs. I, 2.

1951 Metaschizotherium hennigi Dietrich ; Hopwood, p. 21.

1953 Ancylotherium hennigi (Dietrich) Thenius, p. 103.

The occurrence of this chalicothere in Bed I at Olduvai, Tanganyika, has been
reported by Hopwood (1951). The material consists of eight specimens, all from the
left manus, and all collected on the same day from site THC, layerI5. It is therefore
likely to have been derived from a single individual. The specimens, which are
preserved in the British Museum (Natural History), may be listed as follows :

M18785, scaphoid.

M18783, lunate.

M18784, cuneiform.

M18786, second metacarpal.
M18782, third metacarpal.
M1878o, proximal phalanx.
M18781, two middle phalanges.

The scaphoid (Text-fig. 21 A-D) shows much resemblance to that of A. pentelicum.
In proximal view it is trapezoidal rather than triangular in shape, owing to its
broader volar process and flatter dorsal surface. The width (64.5 mm.) and length
(75.5 mm.) are somewhat less than in the specimen measured by Schaub (1943), but
greater than in a cast seen in the Paris Museum. The height (48 mm.) is proportion-
ately greater than in A. pentelicum. The proximal surface is mainly occupied, as in
A. pentelicum, by the articulation for the radius, which is nearly flat, but slightly con-
cave in the dorsovolar direction, extending down on to the dorsal surface near the
ulnar side. The articulation for the trapezoid on the distal surface is rectangular,
rather than ovoid as in A. fentelicum. It is concave in the middle, but towards the
dorsal and volar sides it is crossed by two transverse convexities, that on the volar
side being the sharper of the two. The articulating surface is continuous with that

EAST AFRICAN CHALICOTHERES

227

for the magnum, the line of separation being marked by a blunt dorsovolar ridge
which rises to a cusp near each end. The magnum facet is broader near its volar end
and extends as a tongue (rather broader than in A. pentelicum) to near the dorsal side.
On the ulnar side there are two facets for the lunate, more widely separated than in

q
1
4
1
Viz
ie

Fic. 21. Left scaphoids of Ancylotherium. A—p, A. hennigt, BMNH. M18785. A, proxi-
mal view ; B, distal view ; Cc, ulnar view ; pb, dorsal view. &-H, A. pentelicum, Paris
specimen, corresponding views. All x 4.

Key to facets: /.d. 1.p., lunate (distal and proximal) ; m, magnim ; 7, radius ; /.

trapezoid.

228 EAST AFRICAN CHALICOTHERES

Fic. 22. Left lunates of Ancylotherium. A—D, A. hennigi, BMNH. M18783. A, proximal

view ; B, distal view ; c, radial view ; D, dorsal view. E-H, A. pentelicum, Paris speci-
men, corresponding views. All x 4.
Key to facets : m, magnum ; 7, radius ; s.d, s.p, scaphoid (distal and proximal) ; wi

unciform.

A. pentelicum ; the distal one is slightly concave, and separated from the magnum
facet only by a blunt ridge ; the proximal lunate facet is flat, and makes an angle of
about 70° with the radius facet.

The lunate (Text-fig. 22 A—D) (width 64 mm., length 61 mm., height 58 mm.) is
somewhat smaller than Schaub’s specimen, and larger than a cast measured in Paris.

BEAST APRICAN CHALTICOT HERES 229

In comparison with the Paris cast it appears in proximal view to be more drawn out
in an oblique direction from radiodorsal to ulnovolar. The proximal surface is
completely occupied by the articulating surface for the radius, more definitely
rhomboidal than in A. pfentelicum, but as in that species convex in the dorsovolar
direction and to a lesser degree also in the transverse direction. The radial surface
bears as in A. pentelicum a proximal facet for the scaphoid, flat and triangular, and

Fic. 23. Cuneiforms of Ancylotherium. A—p, A. hennigi, BMNH. M18784, from left manus.
A, proximal view ; B, distal view ; c, radial view ; D, dorsal view. §-H, A. pentelicum,
BMNH. M11346, from right manus (reversed), corresponding views. All x }.

Key to facets : 7, lunate ; w/, ulna ; wn, unciform.

230 EAST AFRICAN CHALICOTHERES

divided from the smaller, elongated, convex distal scaphoid facet by a groove,
into which open some nutritive foramina. The distal surface is divided by a
rounded ridge which connects a dorsal to a volar cusp, and separates the
articulatory surfaces for the magnum and the unciform. Each of these
surfaces is convex dorsally and concave in its central and volar parts. In
comparison with A. pentelicum the distal surface is triangular rather than quadrate,
as the volar process is small and situated more towards the ulnar side of the bone.
On the ulnar side the articulation for the unciform passes insensibly into that for
the cuneiform, which is confined to the distal part of the ulnar side.

The cuneiform (Text-fig. 23 A—D) (width 53.5 mm., length 82 mm., height 43.5 mm.)
is slightly smaller than the British Museum specimen of dA. pentelicum
(M11346), which it closely resembles. It is a flattened bone, ovoid in proximal
view, with the greatest diameter from radiodorsal to ulnovolar. Most of
the proximal surface is occupied by the articulating facet for the ulna,
concave in a dorsovolar direction. Near the volar edge this facet adjoins
that for the pisiform, the separation being merely by a gentle convexity. On the
distal surface of the cuneiform is the saddle-shaped facet for the unciform, concave
in a dorsovolar direction and slightly convex transversely. This facet occupies
rather more of the central portion of the distal surface than in A. pentelicum.
Radially it adjoins the facet for the lunate. The height of the cuneiform is greatest
near its dorsal side.

The second metacarpal (Text-fig. 24) has suffered some surface damage at its
proximal end, and the distal end is lacking. As preserved, the distal surface
possesses radially arranged ridges on the surface of the spongiosa which indicate
that the epiphysis was still separate. The thin compacta, with numerous vascular
canals, supports the view that the specimen was a juvenile. The metacarpal is
slightly smaller than the corresponding bone of A. pentelicum in the British Museum
(M4426) (the greatest length as preserved is 165 mm.). In proximal view the head of
the bone appears more compressed laterally than in A. pentelicum. There is a promi-
nent dorso-ulnar process and a small radial process. The centre of the proximal
surface is occupied by the facet for the trapezoid, flattened and slightly saddle-
shaped, and not so definitely concave as in A. pentelicum. On its ulnar side is a
flat facet for the magnum, narrower than in A. pentelicum. On the ulnar side of
the bone, adjoining the magnum facet, is the overhung facet for metacarpal III,
forming the proximal border of a pit. Schaub (1943) identified in A. pentelicum a
smooth area immediately to the volar side of the trapezoid facet as a surface which
contacted the scaphoid in extreme flexion of the carpus. An apparently correspond-
ing area can be recognised in A. hennigi, but it is less distinct from the trapezoid
facet. Another smooth area on the volar surface of the radial process may have had
the same function. The shaft of the metacarpal is straight and nearly as thick as
wide in the middle of its length ; it does not show the dorsovolar flattening of
A. pentelicum. The radial surface is smoothly convex transversely, very slightly
concave longitudinally. The dorsal surface is marked by a longitudinal shallow
groove which arises proximally about 5 cm. below the dorsal apophysis and fades

EAST AFRICAN CHALICOTHERES 231

out distally. It corresponds to a much broader and deeper groove in A. pentelicum,
where the dorsal and ulnar surfaces are divided by a prominent crest ; this crest is
very poorly developed in A. hennigi. In both species the ulnar surface is scarred
near its proximal end for ligamentary attachment, and the proximal part of the
volar surface is irregularly pitted and pierced by numerous foramina. Immediately
distal to the pitted area the volar surface is roughened for ligamentary attachment.
In A. hennigi the volar surface is more convex transversely than in A. pentelicum.

sy
A

=
o

i
0
Ban

SSS

was

Fic. 24. Left second metacarpal of Ancylotherium hennigi, BMNH. M18786, a, dorso-radial

view ; B, proximal view ; B, ulnovolar view. All x 4.
Key : m, magnum facet ; mc, facet for metacarpal III ; s, possible contacts with
scaphoid ; ¢, trapezoid facet.

Both ends of the third metacarpal have broken off. The shaft is broader and
flatter than that of metacarpal II, but in comparison with A. pentelicum the ulnar
side of the bone is much thicker, the dorsal longitudinal groove is less marked, and
the ridge separating the dorsal and ulnar surfaces is less developed. As in
A. pentelicum the dorsal surface is concave in a longitudinal direction. On the volar
side there is a rather deep longitudinal groove, more marked than in A. pentelicum.
The ulnar surface is extensively roughened, especially proximally. The proximal
part of the radial surface shows a slight longitudinal groove. The proximal end of a
third metacarpal of A. hennigi has been described by Dietrich (1942), but his descrip-
tion is not sufficiently detailed to permit comparison with A. pentelicum.

BAST AFRICAN CHALICOTHERES

Ny
Os
Ww

Fic. 25. A, Ancylotherium hennigi, basal phalanx, BMNH. M18780o, dorsal and side views.
B, BMNH. M12673, from Kaiso, dorsal and side views. c, A. pentelicum, co-ossified basal
and middle phalanges, BMNH. Mgo044, side view. All x $.

The basal phalanx (Text-fig. 254, B) shows most resemblance to one of Major’s
specimens of A. pentelicum, referred by Schaub (1943, fig. 22) to digit IV of the
manus. However, it is shorter (length 81 mm., against 105 mm. in Major’s specimen)
and less broadened at the proximal end (width 52 mm., against 65 mm.). The
Pikermi specimen in Paris differs from both of these in being fused with the middle
phalanx. The distal half of the phalanx is much flattened, the dorsovolar diameter
of the shaft being only about 60% of the transverse diameter. The articulatory
surface for the middle phalanx is flattened and displaced to the volar side of the bone.
The metacarpal articulation faces somewhat more dorsally than in the phalanx
of A. hennigi described by Dietrich (1942) and referred by Schaub (1943) to digit IV,
but both specimens agree in the presence of a step in the dorsal surface immediately
distal to the articulation ; this step occurs also in Major’s specimen of A. pentelicum.
Dietrich’s specimen is a little larger (length 92 mm., proximal breadth 59 mm.),
but more narrowed at the distal end.

The phalanx from the Pleistocene of Kaiso, Uganda (Andrews 1923, Hopwood
1926) is similar in size to the Olduvai specimen, but differs in a number of respects.
The metacarpal articulation lies nearly in the plane of the dorsal surface, and is

EAS) PAI RnGAN GEA iC OM EE RIES 233

proportionately longer and narrower ; the proximal end of the bone is flatter, and
the distal end much deeper. The distal end is broken, and it seems possible that its
depth is due to fusion with the middle phalanx. This specimen is referred to digit II
of the manus, probably of A. hennigt.

The two middle phalanges (Text-fig. 264, B) resemble A. pentelicum in the relatively
flat proximal articulation, with a rather weak median ridge, and in the shallow
trochlear groove at the distal end. One specimen fits the basal phalanx, and may
therefore be referred to digit IV. It differs from the second specimen in being
shorter, in having a more vertical proximal articulation (the proximal volar process
being less prominent) and a shallower trochlear groove. The specimen described
by Dietrich (1942) resembles the middle phalanges from Olduvai, but it is much
smaller, and was probably correctly referred by Dietrich to the pes.

gh
B =
(E

Fic. 26. Middle phalanges of Ancylotherium. a, B, A. hennigi, BMNH. M1878r. c, A.

pentelicum, BMNH. Mgo42. All x .

The Olduvai chalicothere resembles Ancylotherium pentelicum in numerous details
of the bones of the manus, and it is therefore placed in the genus Ancylotherium
rather than Phyllotillon (=Metaschizotherium). The resemblance of Metaschizo-
therium henmigi to A. pentelicum was previously noted by Schaub (1943), and Thenius
(1953) transferred MW. hennigi to Ancylotherium. The Olduvai material is almost

234 EAST AFRICAN CHALICOTHERES

certainly to be identified as A. hennigi, but direct comparison is possible only to a
very limited extent owing to the fragmentary nature of the material. This also
applies to Metaschizotheriwm transvaalensis George (1950), based upon an ungual
phalanx and some teeth from Makapansgat. To judge from the published figures,
upper molars from Makapansgat and the Serengeti are very similar, in spite of a
difference in length/breadth index, and specific distinction seems hardly justified on
present knowledge.

A. hennigi differs from A. pentelicum notably in that the metacarpals are less
flattened and hollowed out dorsally, and the scaphoid is deeper. This suggests that
A. hennigi was less specialised than the Pontian species and not directly derived
from it.

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EAST AFRICAN CHALICOTHERES 237

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THE MIOCENE vines
OF EAST AFRICA

-R. J. G. SAVAGE
| BULLETIN OF

‘BRITISH MUSEUM (NATURAL HISTORY)
| | | : Vol. to No. 8
- LONDON: 1965

Lae f} ah
ef)

FOSSIL MAMMALS OF AFRICA: 19
THE MIOCENE CARNIVORA OF EAST AFRICA

ROBERT J. G. SAVAGE _.

(Department of Geology, Bristol University) =

Pp. 239-316 ; 5 Plates ; 62 Text-figures

BULLETIN OF
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FOSSIL MAMMALS OF AFRICA:
THE MIOCENE CARNIVORA OF EAST AFRICA

By R. J. G. SAVAGE

CONTENTS
Page
I. INTRODUCTION AND ACKNOWLEDGMENTS . : c : : 242
Il. SysTEMATIC DESCRIPTIONS , : : : 3 : 6 243
Order CARNIVORA Bowdich . 5 3 é . : : 243
Suborder CREODONTA Cope : ° 2 : 243
Superfamily ARCTOCYONOIDEA Tacnessae? ¢ . 7 243
Family ARCTOCYONIDAE Murray . : 5 ° o 243
Subfamily OxyCLAaENINAE Matthew : - - . 243
Kelba quadeemae gen. et sp. nov. . F : 0 ° 244
Superfamily OXYAENOIDEA Osborn . : é : C 246
Family TERATODONTIDAE nov. ; . : 0 : 246
Tevatodon spekei gen. et sp. nov. ¢ : 9 j 247
3 enigmae sp. nov. : ; : : : 253
Family HyAENODONTIDAE Leidy . : C c : 257
Subfamily PROVIVERRINAE Matthew : . é - 258
Anasinopa leakeyi gen. et sp. nov. 5 . é é 259
Metasinopa napaki sp. nov. : 6 : ; ; 263
Dissopsalis pyroclasticus sp. nov. : 6 4 4 265
Subfamily HyAENODONTINAE Trouessart . : c . 267
Metapterodon kaiseri Stromer 5 : e 6 ¢ 268
as zadoki sp. nov. : : F : . 270
Pterodon africanus Andrews ; ; : é ¢ 272
Bp nyanzaé Sp. Nov. . c : : 274
Leakitherium hiwegi gen. et sp.nov. . ° : o 276
Hyaenodon (Isohyaenodon) andvewsi sp. nov. . “ : 281
; 5 matthewt sp. nov. . : ¢ 283
PA 55 pilgvimi sp. nov. . c ; 284
Suborder FissipEDA Blumenbach : : 6 a c 288
Superfamily CANOIDEA Simpson : : 4 : 288
Family CANIDAE Gray . : : 5 é : 288
Subfamily AMPHICYONINAE Tugneeeres : : 5 é 288
Hecubides euryodon gen. et sp. nov. : : c 0 289
% macrodon sp. nov. é : : . : 294
Superfamily FELoIDEA Simpson 3 : 2 ; 295
Family VIVERRIDAE Gray : ‘ : : : 2 295
Subfamily HERPESTINAE Gill . : : ‘ : ¢ 296
Kichechia zamanae gen. et sp. nov. 5 : c > 296
Family FELIDAE Gray . : 5 : E 2 4 302
Subfamily NrmRAVINAE Trouessart . : : ; 6 302
Metailurus africanus (Andrews) . 5 ° : : 304
III. CONCLUSIONS AND THE AGE OF THE FAUNA ; : : ¢ 309

IV. REFERENCES i F ; : ‘ : é , : 312

242 MIOCENE CARNIVORA OF EAST AFRICA

SYNOPSIS

Eighteen species of carnivores are described from the Tertiary lacustrine tuffs of East Africa,
mostly from the Kavirondo Gulf in Kenya and the Napak region in Uganda.

Six of the twelve genera (Kelba, Tevatodon, Anasinopa, Leakitherium, Hecubides and Kichechia)
and fifteen species are new. Kelba is referred to the Arctocyonidae and Teratodon is placed in a
new family of oxyaenoid creodonts. Anasinopa, Metasinopa, Dissopsalis, Metapterodon, Pterodon,
Leakitherium and Hyaenodon are all included in the Hyaenodontidae. Hecubides, an amphicyonine
canid, Kichechia, a viverrid, and a species of the felid Metailurus are also described. Conclusions
on the age of the deposits based on the carnivores, other mammalian elements and radiometric
dating converge on Lower Miocene (Burdigalian), with some sites of probable Middle or Upper
Miocene (Vindobonian or Pontian) age.

I. INTRODUCTION AND ACKOWLEDGMENTS

In the first publication of Fossil Mammals of Africa Clark & Leakey (1951) gave an
account of the discovery of Miocene fossils in Kenya, listed the sites in the Kavirondo
and recorded the fauna as then known. They discussed the probable age of the
deposits, based on the known range of mammalian genera recognised in the sequence.
Two of the genera used were carnivores, referred to then as Amp/ucyon and
Pseudaelurus. They concluded that the most probable age for the fauna was Lower
Miocene.

Whitworth (1954) in a later publication gave a brief account of the stratigraphy
on Rusinga Island, together with a location map of sites.

Accounts of the Tertiary geology of the Kavirondo are to be found in Kent (1944),
Shackleton (1951), Whitworth (1953, 1961), Bishop & Whyte (1962) and Bishop
(1963).

The mammal faunas from the Kavirondo pyroclastic deposits are extremely rich.
The insectivores, bats, primates, lagomorphs, tubulidentates, hyracoids, anthraco-
theres and ruminants have already been monographed. With the publication of
detailed studies on the flora by Chesters (1957) and on the mollusca by Verdcourt
(1963), the basis exists for profitable studies on the palaeoecology.

Fifteen out of the eighteen species of carnivore described below are new, six out
of the twelve genera are new and there is one new family. This measure emphasises
the novelty of the fauna, whose age equivalent is little known elsewhere on the
African continent.

Specimens quoted in the text are mostly in the collections of the British Museum
(Natural History) and the National Museum of Kenya, Nairobi; their registration
numbers are prefaced respectively by the initial letters M. and CMF. Occasional
specimens from other institutions are referred to and these named in full in the text.
Throughout the systematic description no reference is made to horizon, since the
conclusions on stratigraphic age depend on identification of the faunal elements.
The subject is dealt with in the final discussion.

My thanks are extended to Dr. L. S. B. Leakey who generously offered me the
carnivores for detailed study and kindly arranged for me to spend a field season in
Kenya visiting the Kavirondo sites and collecting on Mfwanganu Island. Dr. W.
Bishop has kindly allowed me to study the Uganda carnivores.

MIOCENE CARNIVORA OF EAST AFRICA 243

My thanks are also due to Dr. E. I. White and his predecessor as Keeper, the late
Mr. W. N. Edwards, for facilities at the British Museum (Natural History).

For advice, criticism and discussion I am indebted to Dr. W. W. Bishop, Professor
P. M. Butler, Dr. A. T. Hopwood and Dr. T. Whitworth. Mrs. Shirley Coryndon’s
careful and painstaking numbering and cataloguing of the Kavirondo fossils has
been quite invaluable. Mr. D. Erasmus is responsible for the drawings, excepting
Nos. 2, 6-8, 41-43, 47-49 which are by the author. To Mr. E. W. Seavill and Mr. R.
Godwin of Bristol University I am indebted for the photography.

Il. SYSTEMATIC DESCRIPTIONS

Order CARNIVORA Bowdich
Suborder CREODONTA Cope
Superfamily ARCTOCYONOIDEA Trouessart
Family ARCTOCYONIDAE Murray

Diacnosis. Creodonta with teeth primitive, tritubercular, varying towards
sectorial or bunodont. No carnassials or specialised shearing teeth. Premolars
mostly simple, acute, an inner cusp on P4, sometimes on P? and P,,; canines large,
acute, incisors small. Skull moderately long, brain-case small, sagittal and occipital
crests strong, occiput narrow and high, tympanic bulla not ossified. [after Matthew

1937].

Remarks. Matthew’s last revision (1937) is still the basis for arctocyonid studies.
Simpson (1945) differed from Matthew in only one detail; Matthew distinguished
four subfamilies, namely Oxyclaeninae, Chriacinae, Arctocyoninae and Triisodon-
tinae, while Simpson does not recognise the Chriacinae as sufficiently distinct to
merit subfamilial rank; Simpson’s interpretation is followed here and the Chriacinae
are included with the Oxyclaeninae. The remaining two subfamilies are small, com-
prising only seven genera. Simpson lists a further four genera which he places in the
Arctocyonoidae incertae sedis, and to these may now be added Opsiclaenodon (Butler
1947) and from them we may subtract Paroxyclaenus (Russell & McKenna 1961).

Subfamily OXYCLAENINAE Matthew

DracGnosis. Molars tritubercular, sectorial or bunodont, hypocone rudimentary
or distinct; paraconid distinct; premolars simple save sometimes fourth.

REMARKS. The inexactness of the diagnosis emphasises the arbitrary status of
the subfamily. It comprises several little known groups and as it stands represents
the best solution to the problem of affinity. The Arctocyoninae are distinguishable
by their quadrate bunodont molars which have well developed hypocone; the
Triisodontinae have round conical cusps on tritubercular molars, the hypocone is
weak and the paracone and metacone are progressively connate. Among the
incertae sedis genera none displays any features which would suggest affinity with
the new genus described below.

244 MIOCENE CARNIVORA OF EAST AFRICA

The Oxyclaeninae as defined comprise 15 genera, 14 listed in Simpson (1945) plus
Colpoclaenus Patterson & McGrew (1962). All are restricted to the Palaeocene and
Lower Eocene of North America save Arctocyonides which occurs in the Upper
Palaeocene of Europe. In three genera, Carcinodon, Prothryptacodon, and Spanoxyo-
don, no upper dentition is known.

Genus KELBA nov.

Diacnosis. Upper molars tritubercular; paracone and metacone equal sized,
conical but not connate, parastyle prominent; protocone V-shaped with paraconule
and metaconule; cingulum continuous all round, carrying distinct hypocone.

TYPE SPECIES. Kelba quadeemae sp. nov.

Kelba quadeemae gen. et sp. nov.
(Pl tie, is Lext-tigs. 2)

Diacnosis. This is the only known species and the diagnosis is the same as that
for the genus. The name is derived from the Arabic kelb meaning dog and quadeem
meaning ancient.

HototyPe. M.19087. Isolated right upper molar, probably M?.
Locatity. The holotype is from Rusinga Island, Kavirondo Gulf, Kenya.

ADDITIONAL MATERIAL. In addition to the holotype there is an isolated left
upper molar from Mfwanganu Island, Kavirondo Gulf, Kenya, and another molar
from Napak in Uganda.

DEscRIPTION. The holotype is an isolated right upper molar, probably M2. The
tooth is little worn and all details are clearly seen; the outline is quadrate and slightly
asymmetrical due to the development of parastyle and hypocone on opposite corners.
The paracone and metacone are equally low cones, separated by a vestigial meso-
style; the large protocone is V-shaped, its apex equal in height to the paracone and
metacone; the arms of the V carry distinct metaconule and paraconule; the cingulum
is continuous round all sides, though not equally developed throughout; it carries
a low parastyle and low hypocone and is expanded slightly on the anterior and
posterior margins, while being retracted lingually. The tooth is three-rooted, the

Fics. 1, 2. Kelba quadeemae gen. et sp. nov. (1) Right M?. Holotype (M.19087),
Rusinga Is. (2) Left M3. (M.19095), Napak. x3.

MIOCENE CARNIVORA OF EAST AFRICA 245

root below the protocone being much larger than those below the paracone and
metacone.

The second specimen (CMF .4028) from Mfwanganu is a left upper molar, also
probably M2 ,and not so well preserved as the holotype. The teeth are similar in
size but show slight differences in detail. In the Mfwanganu molar the cingulum is
slightly more expanded anteriorly and posteriorly, and the mesostyle slightly more
prominent.

An isolated upper molar, (M.19095) from Napak IV in Uganda is also referred to
the species. This tooth is probably a left M%, transversely elongated, with width
almost twice the antero-posterior length: the protocone is a large V-shaped cusp, the
paracone rises to the same height as the protocone and the metacone is very small;
a cingulum is developed on either side of the protocone and anterobucally to the
paracone. The three roots are situated below the paracone, protocone and metacone;
the protocone root is the largest and the metacone root very small.

REMARKS. Isolated molars with a basic tribosphenic pattern such as the teeth
described above are very difficult to identify with certainty. At this level of organi-
sation there is extremely little difference between the teeth of insectivores, primates,
tillodonts, creodonts, condylarths, pantodonts and dichobunodonts. Beyond the
superficial similarity of these groups, the closest structural resemblances to Kelba
are to be found among species usually referred to creodonts or condylarths. The
condylarths were examined carefully and the case for the inclusion of Kelba there
was found rather less convincing than with the creodonts. Among the Condylarthra,
the Phenacodontidae lack a well developed V-shaped protocone, the Periptychidae
possess more or less symmetrical hypocone and ectocone, and the Meniscothertidae
tend towards lophodont molars. Among the Hyopsodontidae, the Hyopsodontinae
are all small insectivorous mammals with sexi-tubercular molars and the Mio-
claeninae have tritubercular molars which either lack or have a rudimentary hypo-
cone.. Although Kelba is thus placed here among the Arctocyonidae, it will be
necessary when more material is available to review this assessment.

The differences between the two specimens of M? are so slight, and in view of the
proximity of Mfwanganu and Rusinga, there seems little doubt they belong to the
same species.

The new record extends the range of the arctocyonids to Africa. Most of our
knowledge of the group is based on North American finds, and surprisingly the new
species shows no close affinity to either the known European or Asian arctocyonids.
Affinity is greatest with the Oxyclaeninae, and in particular close similarities can be
seen with Metachriacus, Deltatherium, Tricentes and Loxolophus; these genera all
occur in the Palaeocene of North America, the first three in the Middle and the last in
the Lower Palaeocene. In Deltatherium the molars are more sectorial and less
bunodont, the mesostyle is undeveloped and the cingulum extends lingually beyond
the protocone. In Metachriacus the upper dentition is not fully known (M? in the
only specimen with molars is broken lingually), but enough is available to make a
close comparison. Metachriacus molars lack a parastyle, the paracone is slightly
larger than the metacone, and in M! and possibly M? the protocone is asymmetrical ;

246 MIOCENE CARNIVORA OF EAST AFRICA

otherwise the dentition is similar to the new genus. The closest affinities to Kelba
are probably to be found in T7icentes; this genus with Loxolophus has few features
which vary from Kelba. Both Palaeocene genera have bunodont molars, the para-
cone is rather larger than the metacone, and a small parastyle is present. In
Loxolophus the cingulum extends more lingually than in Tricentes.

The four American genera mentioned above differ from each other as greatly as
they differ from Kelba. No clear ancestry for Kelba is obvious among the Palaeocene
forms; on the whole Tvicentes is perhaps closer than any of the others. Kelba would
appear to represent a late survivor of a primitive stock, as probably are Didymoconus
and Ardynictis, two genera of arctocyonids described by Matthew & Granger (1924,
1925) from the Lower Oligocene of Mongolia.

Measurements (in mm.) for Kelba quadeemae

M2 M? M3
M.19087 CMF.4028 M.19095
Holotype
Ant-post. 10°2 9°6 71
trs. 12°3 T7222 Teer

Superfamily OXYAENOIDEA Osborn 1910
Family TERATODONTIDAE nov.

Diacnosis. M3 present; M? transverse; M2 main carnassial, M3 less functional
as carnassial. Premolars large, bunodont, tubercular with thick enamel: P4 larger
than M!. Lower molars with small talonid and metaconid present; M, larger than
M,. Jaw relatively short.

REMARKS. The superfamily Oxyaenoidea Osborn I910 is synonymous with
Pseudocreodi Matthew 1909, Osborn’s name having validity. The superfamily com-
prises only two families, Oxyaenidae and Hyaenodontidae, to which is here added a
third. In the Oxyaenidae M3 are absent in all known genera, M?is transverse and M3
are the functional carnassials: the premolars may enlarge and P® has progressively
developed protocone: the jaw is short and the symphysis robust. The Hyaenodonti-
dae is a much less compact family: in all genera P? lacks a distinct protocone. Within
the Hyaenodontidae are four subfamilies: the Limnocyoninae and Machaeroidinae
lack M3 and M®? is always transverse, (Prolimnocyon is the one exception—M 7? is
transverse and a vestigial M? is present): Hyaenodontinae lacks metaconid on lower
molars: Proviverrivinae retains M? and metaconid on lower molars, the skull is
narrow and jaws long. Gazin (1946) proposed that the Limnocyoninae and Mach-
aeroidinae be given family recognition as the Limnocyonidae. As our concern here is
with the Hyaenodontidae sensu stricto we shall not pursue the wrangle. Clearly the
status of the Creodonta as we know them today is measured; arctocyonids and
hyaenodontids are likely to be among the first victims.

MIOCENE CARNIVORA OF EAST AFRICA 247

Most of the known characters of the Teratodontidae can be found within the
subfamilies of the Oxyaenidae and Hyaenodontidae, but the combination is unique
to the Teratodontidae. In particular the extraordinary premolars mark out the
teratodontids from all oxyaenids and hyaenodontids.

The new family is established to accommodate two species of Tevatodon gen. nov.
described below and in addition I would transfer to the family Quercytherium
tenebrosum Filhol from the Upper Eocene—Middle Oligocene of France.

Genus TERATODON nov.

Diacnosis. Teratodontid of medium size, jaws relatively short. M1! and M?
metacone slightly larger than and connate with paracone; elongate metastyle; M?
slightly larger than M!. P4 bitubercular and larger than M1; protocone almost as
large as paracone. Lower molars with well developed metaconid, trigonid cusps
high, talonid small, paraconid-protoconid shear very oblique. Pg, large with low
single cusp.

Generic name derived from the Greek fevas, a monster or strange creature and
odous a tooth.

TYPE SpEcIES. Teratodon spekez sp. nov.

SPECIES AND DISTRIBUTION. The type species is known from Koru and Songhor.
There is in addition a second species from Songhor described below.

Teratodon spekei gen. et sp. nov.
(Pl. 1, figs. 2, 3; Text-figs. 3-11)

DiaGnosis. Species about size of Vulpes vulpes; metastyle on M? elongate
transversely but not extending beyond the level of the parastyle.

The trivial name is in memory of Captain John Hanning Speke of Dowlish Wake,
Somerset, who in 1859 discovered Lake Victoria.

HorotypPe. M.14307. Left maxilla with P4, M!+? and alveolus of M3; from Koru
near Kavirondo Gulf, Lake Victoria, Kenya.

ADDITIONAL MATERIAL. In addition to the holotype, the type locality has yielded
the following additional specimens:
M.14215. Right maxilla with P*and Mand broken root of M!. (Paratype)
M.14310. Anterior maxillae with canine and P? on both sides and alveoli
of P1. (Paratype).
[These two specimens probably belong to the same individual as the holotype.]
M.14216. Left mandibular fragment with M, and Mg.
M.14308. Right mandibular fragment, symphysial region with two very
worn premolars and part of a third.
The following two specimens from the type locality are referred to the species:
M.14204. Mandible fragment with very worn premolar and root of another
premolar.
M.14225. Right lower canine.

248 MIOCENE CARNIVORA OF EAST AFRICA

Fics. 3-5. Tevratodon spekei gen. et sp. nov. Left maxilla with P4, M! 2. (3) Occlusal

aspect. (4) Lateral aspect. (5) Medial aspect. Holotype (M.14307), Koru. x2.

Songhor, a site about 10 miles NW of Koru, has yielded the following mandibular
remains:

CMF.4039. Right mandible with DP.,, P,, M,,9, and unerupted Msg.
CMF.4040. Left mandible with M,,, and unerupted Mg.

[These two specimens probably belong to the same individual. |
CMF.4041. Left mandibular fragment with P,, 9.

DEscRIPTION. The holotype comprises a posterior maxillary fragment with the
anterior part of the jugal arch, P*, M1 in place and the alveolus of M3: attached to
the specimen is a piece of frontal bone showing the anterior line of the temporal
muscle origin. The strength of the jugal arch and the depth of the temporal insertion
(together with the robustness of the mandible) suggest a strongly built skull with
massive temporal muscles. The right maxilla, M.14215, probably belongs to the
same individual as the holotype; they come from the same site, are the same size
and have the same degree of wear on the teeth. The anterior fragment of maxilla
M.14310 may also belong to this individual.

Mtand Mare closely similar, M? being slightly larger than M!. On the paratype
little more than the roots of M+ remain, while on the holotype the crown of M? is
rather worn; but from what can be seen, it does not differ structurally from M?.
M?has low connate paracone and metacone, small parastyle and metastyle which is
elongated transversely; the metacone is larger than the paracone; the protocone is
V-shaped and attenuated transversely. The alveolus for M? extends transversely
across the palate as far as that of M2, and this evidence taken with the fully developed
M., indicates a sizeable transverse tooth.

P? is startlingly different from the molars; it is present in both holotype and
paratype. The tooth is massive and robust, with two thick roots and the crown sur-
face area is slightly greater than that of M!. The enamel is thick and although in
both specimens the cusps are worn flat, the bases of two cusps are recognizable; these
must have been low tubercular cusps. P? is unknown though presumably present.

MIOCENE CARNIVORA OF EAST AFRICA 249

P? is an extremely stout tooth with two strong roots; the crown forms a low
symmetrical ovate cone, with slight ridge near the base on the antero-lateral side
and suggestion of a cingulum on the posterior margin. P! was very much reduced
and double rooted; it would appear that the size relationships between P! and P?
were similar to those between P, and P, described below. The upper canine is well
but not strongly developed; the antero-posterior diameter at the base of the crown
is much less than that on P?. The canine is flattened laterally, more so on the inner
side with anterior and posterior keels. The tip is not preserved and no trace of a
saw-edge is evident on the proximal parts of the tooth. The premaxillae are missing
though fragments of the nasals survive.

Fics. 6-8. Tevatodon spekei. (6) Maxillae with canines and P2?, occlusal and lateral aspects.
(M.14310), Koru. (7) Right mandible with P, ,, occlusal and lateralaspects. (M.14308),
Koru. (8) Left mandible with P, ,, occlusal and lateral aspects. (CMF.4041), Songhor.
AES 5:

Material of the lower dentition is more abundant and between the specimens
almost a complete dentition is known. Specimens CMF.4039, 4040 and 4041 probably
all belong to the same individual, while specimens M.14308 and M.14216 probably
belong to another individual which could well be the same as the holotype, M.14215
and M.14310. The Songhor individual is immature with the permanent dentition
still erupting while the Koru animal is a fully mature adult with well worn dentition.

Of the three molars, M, is the smallest and M, the largest, and all three are

250 MIOCENE CARNIVORA OF EAST AFRICA

basically similar. M, has a high pointed trigonid, the paraconid-protoconid cusps
are about equally high and form an oblique shearing blade; the metaconid is small
and a stud is present on the cingulum below the shearing edge of the paraconid: the
talonid is slightly shorter than the trigonid and it faces steeply downward and inward
from a high buccal wall to the low lingual edge. In the adult specimen (M.14216) M,
trigonid cusps are worn flat from grinding. M, on the two juvenile jaws (CMF.
4039 and 4040) is similar to Mg, but smaller; the trigonid is worn flat making in-
effective the shearing paraconid-protoconid edge; the paraconid-protoconid edge is
less obliquely inclined. Mg, fully erupted on M.14216, has a trigonid which is rather
bigger than that of M, although the talonid is no larger; the high paraconid-
protocnid shearing blade shows it to be the main carnassial, occluding with M2. In
the juvenile jaws the unerupted M, can be clearly seen in X-ray photographs and in
both specimens the bone is just opened so that the tip of the protoconid is visible.
On specimen M.14216 only M,,. are preserved, together with the posterior root of
M,: the jaw is remarkably robust for the size of the teeth, being thick in proportion
to its depth.

Mandible CMF.4040 is not preserved anterior to M,. Specimen CMF.4039 is
preserved up to and including the symphysis: the coronoid process and condyloid
articulation are missing, as is the tip of the angular process. The body of the
mandible is slender, relatively short and the symphysis large: the symphysial area
is rough and D-shaped. A mental foramen is present on the lateral border behind
P,. The two teeth preserved anterior to the molars are taken to be fully erupted and
worn DP, and P, erupting: P, would have formed in jaw cavity between DP. and
M,. DP gis as large as M,: it has two roots, but the crown is worn flat almost to the
base and no details can be discerned. P, is just erupting above the symphysis and
is much the largest tooth in the series: it is oval with two roots, with thick enamel on
crown which forms a massive but very low pointed cusp. Between the anterior root
of P, and the symphysis is a small cavity, probably for the canine root tip. In the
large cavity within the mandible between M, and DP, was an undeveloped tooth;
only a single cusp tip is calcified and nothing further can be traced; it is presumed
that this tooth is the developing P,.

Specimen CMF.4041 preserves P,,. around the symphysial region; P, is identical
to that in CMF.4039 and is also just erupting through the bone. P, is preserved on
the left side, a small laterally compressed two rooted tooth with low anteriorly placed
cusp. Specimen M.14308 from the type locality has two very worn premolars
preserved, taken to be P, and Ps, on basis of size and position in mandible relative
to symphysis and mental foramina; the anterior half of P, also survives and is again
worn almost to the base of the crown. This robust mandible fragment could belong
to the same individual as M.14216 and the holotype.

M.14204 has very worn premolar preserved, probably P., and behind it the roots
of P,. M.14225 is an isolated canine from Koru, ovate and more compressed on the
inner side, curved more strongly than the upper described; it is of the size and shape
expected of a lower canine of T. spekev.

REMARKS. The premolars are the outstanding feature of Tevatodon. No other

MIOCENE CARNIVORA OF EAST AFRICA 251

Fics. 9-11. Tevatodon spekei. Right mandible with DP, P,, M, 4. (9) Occlusal aspect.
(10) Lateral aspect. (11) Medial aspect. (CMF .4039), Songhor. x1°5.
carnivore or carnivorous mammal known to me has quite such an extraordinary
combination of premolars and molars. Their highly exceptional character, seen in
the maxillae and mandibles from Koru and the mandibles from Songhor makes the
linkage between these two sites (about Io miles apart) plausible. Associated with the
bunodont premolars is the robust build of the jaws and their heavy musculature.

The functioning of this dentition presents occusal and mechanical problems. M#
are clearly the main carnassial teeth, both on basis of structure and wear. The
blades are high, but their obliqueness may be regarded as a primitive feature.
Anterior to these come the grinding premolars: the wear surfaces on the upper
premolars are almost flat and directed slightly dorsally and anteriorly; there is little
definite trace of direction of movement on the surface, but from faint striations it
would appear more likely to have been transverse than longitudinal. Unfortunately

252 MIOCENE CARNIVORA OF EAST AFRICA

the condyloid process is unknown and hence we are ignorant of any articular
modifications. It is difficult, from a purely mechanical viewpoint, to see how a
typical carnivore can perform efficiently the dual function of shearing at the back
and grinding anterior to this: the molars seem likely to impede grinding movements.
Both processes require powerful movements, best achieved with the occusal surfaces
near the fulcrum and a long moment arm from the fulcrum to the line of action of the
muscles (temporal and masseter mainly). The flattened surface of M! and the trace
of wear on the cusps of M? suggest the molars are inevitably occluded during pre-
molar grinding. The premolars could only grind if their height carried them above
the level of the molars; height alone would be useless and must be accompanied by
thickened enamel or more complex tooth structure if it is not to be rapidly lost.
Teratodon premolars are large and have thick enamel.

The only fossil material with which comparison can usefully be made is Quercy-
therium from the Upper Eocene of Phosphorites du Quercy and Gard in France.
Here too can be seen the enlarged premolars, the second being the largest in the
series. Piveteau (1961) has suggested that the specialized dentition of Quercytherium
can be compared with that of hyaenids. The anatomical comparison does not stand
up to detailed examination but functionally there is parallelism in that both combine
crushing and shearing teeth.

In my osteological collection I have a dog skull from Ounianga Kebir, an inhabited
oasis in the midst of the Sahara desert. This skull illustrates what can happen to a
typical carnivore when forced to feed very largely on vegetable material. The people
of the oasis live largely on a diet of rice and dates, with occasional goat and chicken
on festive occasions. The dogs subsist largely on dates, and these mostly rejects too
sandy for human consumption. In the desert without the utmost care, sand covers
all food near ground level: the combination of sand and date stones soon wears down
teeth. On this particular dog skull, all the premolars and molars are worn to flat
surfaces, the M? no less than P?: only the outer rim of P4 remains rather above the
levelled dentition. Further, these teeth show well marked transverse striations
indicating lateral grinding movement.

The feeding habits of Tevatodon remain something of a mystery. The premolar
structure shows a departure from normal and the feeding habits appear to make use
of these modifications. The dentition as a whole seems unbalanced, and far from
being a satisfactory compromise, it seems to get the worst of both: the carnassials
cannot function efficiently because of the large premolars and the premolars cannot
grind efficiently because of their position and the presence of shearing molars behind.
The jaw movements were probably not dissimilar to those of the Ounianga dog.
Instead of desert sand and date stones, we can imagine volcanic dust and stones of
the savannah fruits (well fossilized on Rusinga, see Chesters 1957).

A small stud at the base of the paraconid on the lower molars has been described.
It cannot occlude with anything as it is too low, yet it is very well developed on My
and Mg, though less so on M,. I suggest the stud acted as a guide to erupting teeth,
keeping them in true alignment: if the carnassials erupt with lateral displacement,
the blades will not shear: so long as the posterior edge of the proceeding molar is

MIOCENE CARNIVORA OF EAST AFRICA 253

medial to the stud, then the shear should function. Tevatodon was probably quite
vulnerable to displaced eruptions owing to the shortened jaw.

ArFinities. The classification of Tevatodon presents difficulties: on the basis of
the molars alone, it is clearly to be numbered among the Proviverrinae; but the
premolar specialities and associated shortening of the jaws rule this out. Enlarged
premolars are not uncommon in the Oxyaenidae and are to be found in some of the
carnivorous marsupials, Borhyaenidae: the differences in molar structure, however,
rule out possibility of affinity with these families and the expanded premolars reflect
homeomorphy.

The molar teeth of Tevatodon are comparable with those of Anasinopa described
below and with Sinopa. Anasinopa is much larger and the shear on the carnassials
less oblique; Sznopa is intermediate between the other two.

M2 M,

Angle between shear and Angle between shear and

paracone-metacone line paraconid-metaconid line
Teratodon 80° 50°
Sinopa 60° 45°
Anasinopa 50° 40°

The Teratodontids could be regarded as an early offshoot of the Oxyaenoidea,
close to the Proviverrinae, retaining M? and molars with very oblique shear, while
specializing in the development of crushing premolars.

TABLE I

Measurements (in mm.) for Tevatodon spekei

Cc ip pe Mt M2? P, 1B P, M, M, Mg,
M.14310 ap gO 12°9
trs 5°7 83

M.14307 a—p 6:7 6:8 6:8
Holotype trs 9°5 9°5 10°7
M.14215 a—p 6°5 6°7
trs 9°8 II‘O
M.14216 a-—p 73} 9°4
trs 5°0 6°3
M.14308 a-—p 12°76 108
trs 7°4 8:8
CMF .4039 a-—p II*5* gop — 7°4
trs 6°5 4°9 3°8 5°1
CMF .4040 a—p 6:0 7°3
trs 3°8 4°9
CMF .4041 a-—p (G40) 11
trs Py) 7:0

*Tooth erupting; measurement approximate. D, Deciduous premolar, probably DP3

Teratodon enigmae sp. nov.
(Pl. x figs. 4, 5; Text-figs. 12-18)

Diacnosis. Differs from the type species in having shorter and more robust jaws,

254 MIOCENE CARNIVORA OF EAST AFRICA

and very heavy premolars. On M? the metastyle extends laterally beyond the level
of the parastyle. Both upper and lower canines are large and the snout is blunt.

HorotypPeE. M.19088. Facial region with dentition fairly complete behind the
incisors. From Songhor, near Kavirondo Gulf, Kenya.

ADDITIONAL MATERIAL. A left mandible, M.19089, from the same site and
possibly belonging to the same individual as the holotype, is referred to the species.

DESCRIPTION. The holotype comprises a reasonably complete facial region with
most of the dentition posterior to the incisors. Maxillae, nasal and palatine bones

‘
\

it
it

Fics. 12-14. Tevatodon enigmae sp. nov. Maxillary region. (12) Occlusal aspect.
(13) Right lateral aspect. (14) Left lateral aspect. Holotype. (M.19088a), Songhor.
ae

MIOCENE CARNIVORA OF EAST AFRICA 255

are preserved and the sutures visible. The complete nasals are entirely horizontal,
elongate and with parallel sides: the anterior edge is transverse with a very short
lateral arm adjoining the premaxilla. The premaxillae are broken anteriorly, but the
root of one incisor remains on the right side; posteriorly they extend back and overlap
the nasals for some 15 mm. Between the large root of the upper canine and the
premaxillary border of the maxilla is a deep groove, the lower part of which may have
accommodated the lower canine. There are in addition fragments of right frontal and
parietals, the latter showing high sagittal crest.

The upper molars are similar to Tevatodon spekei but beyond this close similarity
ends. The jaw is short and very much constricted in the premolar region. The
mandible and beginning of the jugal arch are heavily built. Other than fractures due
to fossilization, the bone is in good condition and shows no sign of fracture during life
or any other abnormality. In contrast to this the dentition is bizarre. The beast is
presumed to have had three molars, of which M? and Mare well preserved on both
sides. M?is distinguishable from that of Tevatodon spekei only by the more elongate
metastyle, which is extended well beyond the level of the parastyle. Mis a trans-
verse molar of the size and proportions expected of Tevatodon spekei: it has V-shaped
protocone, connate paracone and metacone, the paracone slightly larger than the
metacone, elongated parastyle extending to meet the metastyle of M2.

In the short gap between the canine and M? is crowded a grotesque array of
‘premolars’, which almost defy description. These ‘teeth’, as will be seen from the
illustrations, cannot be numbered P!4; they possess massive roots, they are not
symmetrical on left and right, the crowns are worn into a longitudinal concave arc
and are without trace of a cingulum, the largest tooth is midway between the canine
and M2 and is so broad that a palatal gap of only 4 mm. is left.

Fic. 15. Teratodon enigmae. Maxillary region, anterior aspect. Holotype
(M.19088a), Songhor. X1I°‘5.

The robust mandible has a large symphysis and two mental foramina, the larger
and more posterior under ?P.. The five alveoli at the back of the mandible presum-
ably are for the three molars, though it is far from clear to see how three teeth, each
of which could be expected to have two roots, can fit into five alveoli. The root of
the canine is visible beside the symphysis and on its outer edge the root tip of ? Pj.

256 MIOCENE CARNIVORA OF EAST AFRICA

Between this root tip and the molar alveoli are four tooth stumps, so worn that
no characters remain: a little enamel is left on the posterior edge of the last of these
four teeth: the wear surface forms a longitudinal concave arc as on the upper
dentition.

Fics. 16-18. Tevatodon enigmae. Left mandible. (16) Occlusal aspect.
(17) Medial aspect. (18) Lateral aspect. (M.19089), Songhor. X1I‘5.

MIOCENE CARNIVORA OF EAST AFRICA 257

RemARKS. Although the skull bones are in places broken, the joins are clear
and there is no doubt the pieces have been assembled correctly. Hence the possibility
that pieces of several individuals, or even several species, being assembled together
is ruled out. It seems inconceivable that this individual represents the norm of the
species. The predominance of transverse striations on the upper and lower ‘premolars’,
together with the shape of the facets, suggests that these are genuine occlusion
facets and not weathering surfaces. It must follow that the specimen is that of an
abnormal individual. If the abnormality was caused by damage to the jaw and or
tooth germs, then more asymmetry would be expected, and some sign of bone repair
inevitable. No pathological cause is known which would produce such bizarre
patterns. This leaves only a congenital cause for the abnormality and the individual
must be a mutant.

The norm of the species probably represents something quite different from
Teratodon speket. The parallel sided nasomaxillary region, expanding rapidly from
the springing of the jugals, the flat topped and blunt nosed snout with large maxillo-
turbinal cavity, recall proportions seen in Enhydra, the sea-otter. The cheek denti-
tion in Enhydra is relatively large and the enamel thick—adaptations to shell-crush-
ing. It is tempting to think of T. enigmae as a shell-crushing aquatic form, breaking
molluscs loose with its strong canines and crushing them with the heavy premolars.

Without insisting that the above reasoning is water-tight and that no other
solutions are possible, I submit that on the available evidence it seems the most
plausible explanation. It would greatly help to have more material: the population
may represent one of those interesting short periods of genetical instability so rarely
preserved, when many new prototypes are appearing and disappearing in the process
of establishing a few new strains.

Measurements (in mm.) on Tevatodon enigmae (M.19088a) :

C M2 M3

Right side a—p Te 2 7°0 53
trs TeBe I1°6 10°4

Left side a—p 13°6 71 5°2
trs 9°2 II*2 I0°4

*Measurement taken on root.

Family HYAENODONTIDAE Leidy

DiacGnosis. Creodonta with upper molars either three or reduced to two; two
front upper molars specialised as carnassial teeth either tuberculo-sectorial or
completely sectorial; last upper molar, when present, transversely extended; all the
lower molars specialised as carnassial teeth ; P+ two-rooted, except in some specialised
genera; primitive forms with long and slender skulls; tail long and heavy; later
forms with more robust skull, claws blunt; cursorial adaptations to a varying extent.
[after Pilgrim 1932].

REMARKS. The diagnosis omits details of post-cranial characters, to be found in
the diagnoses of Matthew (1909) and Denison (1938). The Hyaenodontidae together
with the Oxyaenidae make up the superfamily Oxyaenoidea. (=Pseudocredodi of
Matthew 1909 and Denison 1938). Of the four subfamilies of Hyaenodontidae,

258 MIOCENE CARNIVORA OF_EAST AFRICA

Denison (1938) grouped together the Limnocyoninae and Machaeroidinae as short
broad skulled types, and the Proviverrinae and Hyaenodontinae as long faced narrow
skulled types, while Gazin (1946) separated the Limnocyoninae and Machaeroidinae
in a new family, the Limnocyonidae.

Subfamily PROVIVERRINAE Matthew

DiaGnosis. Hyaenodontidae with narrow skull and long face; M3; molars
tritubercular above, tuberculo-sectorial below; metaconids present on lower molars;
carnassial specialization less advanced [After Matthew 1909].

RemMARKS. The skull and facial characters distinguish the subfamily from the
Limnocyoninae and Machaeroidinae: the tooth characters distinguish it from the
Hyaenodontinae. Of the 12 genera comprising the sub-family, 7 of these are listed
by Simpson (1945) and four have been added since; Stovall (1948) added/schnognathus
and three are due to Matthes (1952), Prodissopsalis, Leonhardtina and Getselotherium.
The Eocene of North America has yielded Sinopa and Tritemnodon, and from the
European Eocene come Prorhyzaena, Proviverra, Paracynohyaenodon, Prodissopsalis,
Leonhardtina and Geiselotherium. (Simpson also includes in his list Cynohyaenodon
and Galethylax, both of which I consider synonymous with Proviverra). The Oligocene
has yielded Jschnognathus in North America and Metasinopa in Egypt. The only
Miocene form is Dissopsalis from India. To these is now added a further genus from
East Africa.

CoOMMENT.—Matthes (1952) described a new creodont fauna from the Middle
Eocene lignite beds of Geiseltal; the six new proviverrine species described are
placed by Matthes in four new genera. Unfortunately the photographic plates have
reproduced very poorly and there are no diagrams of the dentitions, hence interpre-
tation is seriously impeded. None of the new species or genera is very close to the
new African genus described below, but the taxonomy in the paper calls for some
comment. I consider two of the species, Imperatoria gallwitzt and I. hageni to be
identical. Both are known only from mandibles and lower dentitions: they have
identical morphological characters and the size differences are so slight that they
are well within the range of individual variation, as seen in the following figures
(from Matthes 1952):

I. gallwitz (mm.) I. hageni

M)-3 38 40
P,-M; 80 85
Length M, Il 12
> M, 13 14
M3 14 14

Imperatoria is known only from mandibles and lower dentitions and Prodissopsalis
is known only from skulls and maxillary dentitions. Both occur in the same beds
at the same sites; both are the same size. The dentition of Imperatoria corresponds
exactly in composition, pattern and size with that which could be envisaged for the

MIOCENE CARNIVORA OF EAST AFRICA 259

lower dentition of Prvodissopsalis, as shown in the following figures where comparison
is made with the upper and lower dentition of the closely related genus Sznopa.

Sinopa grangervi a M1-8 22-7 mm. UGE’ 8. c P1_M? 56:8 EOC
(Matthew 1906) bi, .2o7 mm) ib) 5 dP,-M,601 d Ave
Prodissopsalis
eocaenicus a M!-3 32 mm c P1_M? 81 mm.
(Matthes 1952) 10a IOC

: — = 815 —— = 9°76
Imperatoria b d
gallwitz b M,-, 38 mm. d P,-M, 83 mm.
(Matthes 1952)

I therefore consider Imperatoria a nomen nudum and all material previously
referred to it to be synonymous with Prodissopsalis eocaenicus.

Genus ANASINOPA nov.

Dracnosis. Proviverrine with dental formula 2:43; Skull elongate and jaws

slender: P, two-rooted; lower premolars compressed, crowded posteriorly, length
slightly greater than height; P, with a distinct talonid; P*4 tubercular, parastyle
smaller than metacone: M1!*? tritubercular, triangular, metacone and paracone
close together but not connate, metastyle shearing, metaconule and paraconule
present; protocone V-chaped; M3 transverse; M,_, tuberculo-sectorial, metaconid
present, Mg, largest and M, smallest, protoconid and paraconid subequal, their
height approximately equal to trigonid length, metaconid much smaller, talonid
basined; M,, talonid length slightly less than trigonid, M., talonid much reduced.

TyPE SPECIES. Anasinopa leakeyi sp. nov. The only species.

Anasinopa leakeyi gen. et sp. nov.
(Eat, tes Ong bi 2= Wext-igs, 19-22)

DiaGnosis. The generic characters form the basis of the diagnosis. Species
about the size of the European wolf (Canis lupus). C,-—M,=92 mm;
P, — M, = 84 mm; M, — M, = 41 mm; M! — Mest. = 34 mm.

HoLotyPe. Five pieces comprising maxillae and mandibles of one individual.

M.19g081 a _ Left maxilla with P4, M! and alveoli of P?+®.

- b Right ,, » M?*2 and alveolus of M3.
f c Right mandible with C, P,,, M,-3.
»” a Left yy ” Moi:

a”) ” ”

C and P,.

260 MIOCENE CARNIVORA OF EAST AFRICA

Locaity. Rusinga Island, Lake Victoria, Kenya.

ADDITIONAL MATERIAL.
From Rusinga Island, Site 106 :—
CMF.4044 Right M2
CMF.4045 Right M,
From Rusinga Island, unsited:—
CMF.4018 Right mandible fragment with M,_,
CMF.4019 Right M2
CMF.4020 Right M1
CMF.4047 Left P4
CMF.4048 Right M?
CMF.4049 Left M, (trigonid only)
CMF.4050 Left P,
CMF.4051 Left M, (trigonid only)
CMF.4052 Left P,
CMF .4054 Right M,
CMF.4055 Right mandible fragment with P, ,
CMF.4056 Right M, (trigonid only)
CMF.4058 Left M2 (broken)
From Karungu:—
CMF.4046 Left P4
From Maboko Island :—
CMF.4043 Left M,
From Mfwanganu Island :—
CMF.4053 Right mandible fragment with C, P, roots, P, and part of P,
CMF .4057 Right M,
Site unknown :—
CMF.4059 Right P,

DEscriIPTION. None of the skull is preserved beyond that surrounding the teeth.
The alveoli of the two-rooted P? and P® are preserved and the infra-orbital foramen
is present above the posterior alveolus of P?. P*is tubercular; the transverse width
is approximately equal to the antero-posterior length; paracone is conical with small
parastyle anteriorly and metacone posteriorly ; protocone well developed and slightly
anterior to paracone, its posterior border continuous with metacone base, and anterior
border constricted and separate from parastyle; order of cusp size commencing
with the largest is paracone—protocone—metacone—parastyle; deep valley between
paracone and protocone; metacone more or less connate with paracone. M! tuberculo-
sectorial; transverse width slightly greater than antero-posterior length; paracone
and metacone tubercular, metacone slightly larger than paracone, both cones close
together but not fully connate; small parastyle; metastyle trenchant, connate with
metacone and with weak oblique shear; external cingulum; large lunate protocone
with small paraconule and metaconule on the arms. M2? structurally similar to M+
but slightly larger and metastyle more sectorial. M* unknown; small transverse
two-rooted tooth.

MIOCENE CARNIVORA OF EAST AFRICA

261
None of the lower incisors is preserved, but the narrow symphysial region
indicates three closely packed teeth. Only the base of the lower canine is preserved

and this indicates a slender and moderate sized tooth. P, follows immediately

<2)
\

y if HN ZY) \\ A \
wl ( PAY >I
Ab 4 eel Oe 1G: p \ . \

WD gx

S ( A

Fics. 19-22.

Anasinopa leakeyi gen. et sp. noy. (19) Reconstruction of right maxilla
with P4, M? 2; based on M.19081a,b; occlusal aspect. (20) Right mandible with C, P,-4,
M;-,; occlusal aspect. (M.19081c).

(21) same as Fig. 20; lateral aspect.
Fig. 20, medial aspect.

(22) same as
Holotype (M.19081r), Rusinga Is. x1.

262 MIOCENE CARNIVORA OF EAST AFRICA

behind the canine without any diastema; it is a small two-rooted tooth with a posterior
cingulum. P, is much larger and P gis slightly larger again, with a posterior cusplet.
P,is the largest premolar; to the main cusp is joined posteriorly a short talonid with
high external cusp and low internal ridge. M, trigonid with metaconid considerably
smaller than subequal paraconid and protoconid, the latter two cusps apparently
sectorial with weak oblique shear, but trigonid cusps worn to stumps; talonid
slightly shorter than trigonid, shallow basin with high buccal and low lingual
bordering ridges. M, structurally similar to M,, but rather larger. M, with trigonid
much larger than M,; metaconid small, paraconid and protoconid with strongly
developed oblique shear; talonid very small, less than half length of trigonid, with
buccal bordering ridge and also an oblique ridge crossing inwardly over the sloping
basin.

The mandible is long and slender. The symphysis is three times as long as it is
high, extending as far back as P,. The condyle is rounded and elongated transversely ;
the slender curved angular process for the masseter reaches back to the level of the
condyle. The coronoid with marked anterior ridge arises immediately behind M,
and sweeps high above the condyle in a typically carnivore fashion. The anterior
mental foramen is below a point between P, and P,; the posterior foramen is below
Pe

REMARKS. It is regrettable that so many of the genera in the sub-family are
poorly known, often only from fragments. The presence of metaconids on the lower
molars however distinguishes them from the hyaenodontines.

Proviverra is a very small form with connate paracone and metacone on the upper
molars; premolars are short and high, and lower molars have high metaconid almost
equalling protoconid. In Paracynohyaenodon the paraconid is very low, smaller
than the metaconid. IJschnognathus is known only from a fragmentary mandibular
symphysis and its relationship to the proviverrines must remain in doubt. Metasinopa
is very small, lacks P, and has very reduced metaconids on lower molars. In Dis-
sopsalis the parastyle is lacking on P4 and vestigial on the upper molars; metaconule
and paraconule are not present on M!*?. The diagnosis of Geiselotherium given by
Matthes (1952) comprises nine negative statements about the genus, making it
almost impossible to recognize: size alone excludes it from consideration with
Anasinopa leakeyi, Other characters could be listed which differentiate these
genera from Anasinopa, but those given are sufficient to establish the distinction.

On the basis of molar tooth structures, the closest similarities to Anasinopa are
to be found in Sinopa and Tritemnodon. Tritemnodon lacks a parastyle on P4; the
upper molars have connate paracone and metacone, and lack paraconule and
metaconule. Sinopa species have large parastyle on P4, larger than in Anasinopa;
M!*? have widely separate paracone and metacone: in the lower dentition P, is
single-rooted; P, shows little or no development of talonid; Mg, tends to be smaller
than M, and the talonid little reduced; the talonids of M,_, are more fully basined
than in Anasinopa.

Anasinopa appears to represent a stage of evolution between Sinopa and Tritemno-
don (Middle Eocene of N. America). It is less advanced than Metasinopa (Lower

MIOCENE CARNIVORA OF EAST AFRICA 263

Oligocene of Egypt) which has lost P, and has very reduced metaconids on lower
molars.

TABLE 2

Measurements (in mm.) on holotype of Anasinopa leakeyi (M.19081 a-e)

ae M! M2 M3
M.19081 a a—p 113308) 12°4
trs 13°3 13°6
M.19081 b a—p 12°2 14°2
trs 13°0 15°3
(e Py Py Ps in M;, Ms, Ms,
M.19081 c a—p 83 6:0 9°7 I1°6 13'0 12°3 14° 16°6
trs 5°8 3°5 51 5°8 6:9 Fit 8-2 8°5
M.1g081 d,e a-p 8-1 13°2 14°5 15°5
trs 5°6 73 79 8°7

Genus METASINOPA Osborn 1909

Diacnosis. ‘P;, Mg. As in Pterodon and Apterodon a basal talonid is preserved,
which distinguishes this animal from Hyaenodon. A persistent metaconid on M,
and M, distinguishes this animal from Pterodon and Afterodon and relates it to
Sinopa and Tritemnodon. The lower premolars are small and P, absent. Heels of
the lower molars small, trenchant.’ [after Osborn 1909].

Type Species. Metasinopa fraasi Osborn. Nearly complete left mandible (Amer.
Mus. No. 14453) from the Lower Oligocene of Fayim, Egypt.

REMARKS. Osborn (1909) established the genus on the mandible and tentatively
referred to the same genus a maxilla from the same beds (Amer. Mus. No. 14452).
Osborn further suggested that Sinopa ethiopica Andrews (1906) was probably a
species of Metasinopa. The holotype of S. ethiopica is a left mandible with P,, M,_.,
and Andrews provisionally placed it in Simopa: Osborn’s suggested reference to
Metasinopa seems reasonable.

Metasinopa napaki sp. nov.
(Text-figs. 23, 24)
Diacnosis. Mz, with talonid half as long as trigonid; metaconid present, proto-

conid and paraconid trenchant, talonid sloping downward and lingually from
buccal ridge.

HorotyrPe. M.19097. Left mandible fragment with broken Mg.
Locatity. Napak I, Karamoja, N.E. Uganda.

DEscRIPTION. Only a broken left M, is known. The protoconid and paraconid
are well developed and have trenchant outer face: only the base of the metaconid
is present and it appears to be a small cusp: the talonid is half as long as the trigonid
and much narrower; the incipient basin has high outer and low inner margin.

204 MIOCENE CARNIVORA OF EAST AFRICA

REMARKS. The fragmentary evidence does not warrant any firm deductions.
The specimen is provisionally included in Metasinopa largely for convenience and
because there is no evidence for separation. To the same species is also provisionally
referred a maxillary fragment with P*+4 (M.19096). The specimen possesses the root
of P? and complete single cusped P3: P* has strong protocone but no parastyle;
the metacone is smaller than protocone; a cingulum is present anteriorly and buccally.
The absence of a parastyle on P4 prevents its inclusion with Sinopa, Anasinopa,
Dissopsalis or Prodissopsalis. The animal was the same size as the holotype of

M. napaki.

23 24

Fics. 23, 24. Metasinopa napaki sp. nov. (23) Left mandible with Mg.
Holotype (M. 19097), Napak. (24) Maxilla with P**4. (M. 19096), Napak. x2.

Metasinopa napaki is smaller than M. fraasi and larger than M. ethiopica, and
differs from both in having a proportionately longer talonid on My. Until more
material is available it would be best to retain Metasinopa for the inclusion of the
following specimens :—

Metasinopa fraasi (type species) Amer. Mus. 14453 Left mandible
Lower Oligocene

of Fayim, Egypt.

Metasinopa (?) sp. Amer. Mus. 14452 Left maxilla
Lower Oligocene
of Fayim, Egypt.

Metasinopa ethiopica Geol. Mus. Cairo C.10193 Left mandible
Lower Oligocene of

Birket-el-OQurun,

Egypt.
Metasinopa napaki M.19097 Left mandible
Napak I, Karamoja,
Uganda.
” M.19096 Right maxilla

Napak I, Karamoja,
Uganda.

MIOCENE CARNIVORA OF EAST AFRICA 265

Measurements in mm. on Metasinopa napaki

M, IPs) p4
ant-post 12°0
M.19097 lat 6°6
trigonid length 79
M.19096 ant-post 8-6 9°8
lat 5:0 9°8

Genus DISSOPSALIS Pilgrim 1910

Dracnosis. Dental formula I ?, C+, P 4, M 3: carnassials MZ and M32:
protocone prominent, especially on P4, and placed anterior to and remote from para-
cone: parastyle reduced: metastyle prolonged into shear: premolars robust with well
developed cingulum: P* almost as large as M1; P, larger than M,. Molars trenchant ;
M!*? with large protocone, connate paracone and metacone, shearing metastyle;
M® very small: M, three cusped trigonid and basined talonid; M, paraconid-proto-
conid shear strong, without metaconid, talonid reduced to small peg. [After Colbert

1933].

Type Species. Dissopsalis carnifex Pilgrim. The generic name reflects the double
carnassial shear on two sets of molars, M5 and M3.

LocaLity AND Horizon. Type species from Chinji, Salt Range, Siwalik Hills,
India; Chinji stage, ?>Middle Miocene.

In addition to the type species Pilgrim (1910, 1914) described a second and smaller
species, D. ruber, from the same horizon and locality.

REMARKS. Pilgrim’s descriptions, based on fragmentary material, are a remark-
able example of his insight. Colbert (1933) had available a skull of D. carnifex
collected on the American Museum Expedition, and has given a full account of it,
together with a referred mandibular fragment.

Dissopsalis pyroclasticus sp. nov.
(Pl. 3; Text-figs. 25-27)

DIAGNOsIS. Species much larger than D. ruber and approximately same size as
D. carnifex but jaw shorter and teeth crowded. No diastema between premolars
nor between P, and canine. Metaconid progressively reduced; small on M,,, vestigial
on M, and only pin-point on Mg. Shear progressively improved from M, to Mg.
Talonid basined on M,, 4; minute peg on Msg.

HoLotyPe. M.19082. Right mandibular ramus containing P,, M,_, and alveoli
of canine, P, 5. No other specimens can be assigned to the genus with certainty.

Locatity. Kaboor, Northern Frontier District, Kenya.

2606 MIOCENE CARNIVORA OF EAST AFRICA

eM ff
Si

Fics. 25-27. Dissopsalis pyroclasticus sp. nov. Right mandible with P,, M,-..
(25)Occlusal aspect. (26) Lateral aspect. (27) Medialaspect. Holotype(M.19082), Kaboor. x1.

DeEscRIPTION. The mandible is robust and heavy. The symphysial junction
extends back as far as the middle of P,. The canine alveolus is not fully preserved
but suggests a normal sized canine. P, is single rooted and crowded behind the
canine. P,and P, both had large double roots and were tightly packed against each
other close behind P,. P, is a large heavy tooth; the cusp is keeled anteriorly and
posteriorly, the posterior keel continuing into a small accessory cusp, trenchant
buccally and sloping down to a cingulum on the lingual side. M, is smaller than P,;
the trigonid is greatly worn, and of the three cusps the protoconid was larger than
the paraconid, while the metaconid was very much smaller than either of the others;
the talonid is broken, but must have been about the same length as the trigonid,
basined with high buccal rim and low lingual rim. M gis larger than M, but structur-
ally similar; the metaconid is reduced to a minute peg and the paraconid-protoconid

MIOCENE CARNIVORA OF EAST AFRICA 267

has a strong oblique shear. M, has a larger trigonid than M, and hence bigger shear
area on paraconid-protoconid; the metaconid is detectable only as a pin-head projec-
tion of enamel on the postero-internal slope of the protoconid; the talonid is reduced
to a small peg.

REMARKS. The similarity of the new species to D. carnifex is striking. The
differences are so small that it is difficult to determine which is the more or less
advanced. The shorter jaw and more crowded dentition, together with the more
reduced talonid on M, suggest that D. pyroclasticus is slightly more advanced than
D. carnifex. The robust jaw and heavy premolars are reminiscent of Quercytherium
from the Phosphorites du Quercy, though in this genus the molars are less specialised.

Measurements (in mm.) on holotype of
Dissopsalis pyroclasticus (M.19082)

P, M, M, M,
a—p 16°0 ca. 13°0 17°5 16°5
trs 9:0 7°8 8°7 9°0

Subfamily HYAENODONTINAE Trouessart

DiaGnosis. Hyaenodontidae with narrow skull and long face; M3 or M3;
molars sectorial, length greater than width; M3 small and transverse or absent;
M1!*? with paracone and metacone completely or nearly connate, protocone reduced
or absent; lower molars without metaconid, talonid vestigial or absent.

REMARKS. Simpson (1945) listed seven genera in the subfamily; of these, four
are clearly good genera, Pterodon, Apterodon, Metapterodon, and Hyaenodon:
Propterodon is less well known. Hemipsalodon is a synonym of Pterodon and
Dasyurodon a synonym of Apterodon. To these is here added a new genus,
Leakitherium.

TABLE 3
Distribution of Hyaenodontine Genera

EUROPE AFRICA ASIA N. AMERICA
LOWER MIOCENE Hyaenodon
UPPER OLIGOCENE Hyaenodon
MIDDLE OLIGOCENE = AHyaenodon Hyaenodon Hyaenodon
A pterodon
LOWER OLIGOCENE Hyaenodon Hyaenodon Hyaenodon Hyaenodon
A ptevodon A pterodon
Pterodon Ptevodon Pterodon
Metapterodon
Leakitherium
UPPER EOCENE Hyaenodon Hyaenodon Hyaenodon
Ptevodon Pterodon Ptevodon
Propterodon

MIDDLE EOCENE Propterodon

268 MIOCENE CARNIVORA OF EAST AFRICA

Genus METAPTERODON Stromer 1926

D1aGnosis. Hyaenodontine with M3; P*-M3 slowly increase in size; M? small
and transverse; M!*? sectorial with buccal cingulum, parastyle minute or absent,
protocone present; P® simple two rooted.

TYPE spEcIES. MW. kaiseri Stromer from Elizabethfeldern, S.W. Africa; horizon
stated by Stromer (1926) to be Lower Miocene.

A second species from Rusinga is described below. Pterodon biincisivus Filhol
(1876) from the Lower Oligocene of Phosphorites du Quercy, France is here trans-
ferred to the genus Metapterodon.

REMARKS. Stromer’s original diagnosis placed much emphasis on skull features,
in particular the position of the infra-orbital foramen. I consider these plastic
architectural modifications and thus variable from species to species, depending
largely on size and adaptation requirements. From Schlosser’s remarks, it appears
that he compared Metapterodon kaisert with only two species of Pterodon, the type
species P. dasyuroides and P. africanus from the Fayam. He makes no mention of
the other five species of Ptervodon described prior to 1926.

A critical phrase in Stromer’s diagnosis is ““Zahngrésse von P? bis M? stark zunehe-
mend’’. With this I disagree; the tooth size, as seen in Table 4 does increase from
P? to M2, but not greatly. M? is only about one-third as long again as P*. The
determinative feature is that the increase is much less than that found in Pterodon
species. In Metapterodon the reduced parastyle and well developed protocone (as
noted by Stromer) form clear generic distinctions from Pterodon.

On the basis of the above diagnosis Pterodon biincisivus Filhol falls within the
genus Metapterodon: it also has the infra-orbital foramen above the border of P?
and P“as in M. katseri.

Metapterodon kaiseri Stromer
(Pl. 4, fig. 1; Text-fig. 28)
1926 Metapterodon kaisert Stromer: 110-112, pl. 40, figs. 13, 14
Diacnosis. Metapterodon species of about size of Alofex: skull elongate and
slender, infra-orbital foramen above border of P3-P4, P? simple two-rooted: upper
molars with outer cingulum, parastyle absent from P4 and M}, rudimentary on M?;
protocone well developed on M1**. [After Stromer 1926].

HototyrPe. Left skull fragment with P?-M?, from Elizabethfeldern, S.W. Africa.
Stromer (1926) considered the deposit to be Lower Miocene in age on the basis of
similarity of fauna with East African fauna. 1926 < I Munich.

ADDITIONAL MATERIAL: CMF.4038. Right maxilla with P?—M? from Karungu,
Kavirondo Gulf, Kenya. CMF.4066a Left maxillary fragment with P4-M?, teeth
broken. CMF.4066b Right mandibular symphysis with broken canine root and two
broken premolars. CMF.4066c Left mandibular fragment with roots of molars. All
from Rusinga Island, Kavirondo Gulf, Kenya.

DESCRIPTION: On specimen CMF.4038 little more than the bone around the
teeth is preserved. Posteriorly the root of the jugal arch is preserved: this rises nearly

MIOCENE CARNIVORA OF EAST AFRICA 269

Fics. 28, 29. Metapterodon kaiseri Stromer and Metapterodon zadoki sp. nov. (28) M.
kaiseyi. Right maxilla with P3-M$; occlusal, medial and lateral aspects. (CMF.4038),
Karungu. (29) M.zadoki. Right maxilla with M! 2; occlusal, medial and lateral aspects.
Holotype (M.19094), Rusinga Is. Both 1.5.

270 MIOCENE CARNIVORA OF EAST AFRICA

vertically and shows no tendency to spread horizontally. The infra-orbital canal
issues to the bone surface in the space between the root tips of P? and P4. P®isa
simple two-rooted tooth with prominent internal cingulum and small posterior
accessory cusp. P* is three rooted, larger than P?, with robust central cusp, well
developed posterior accessory cusp and protocone of about same size; the protocone
is centrally placed opposite the main cusp and the external cingulum is well marked.
M lis slightly larger than P4; the protocone is missing, but from the root it appears
to have been about as large as that on P4; the paracone and shearing metacone are
about equal in length though in the holotype both are much worn. The external
cingulum is prominent and continues anteriorly round the paracone. M? is larger
than M!, with prominent protocone placed well anteriorly and remote from the
paracone, which is a stout conical cusp from whose anterior border arises a minute
parastyle; the metacone is about the same length as the paracone and forms a
strong shearing blade, separated by a cleft from the paracone; the angle of shear is
very low, being almost parallel to the longitudinal axis; as in M! the external cingu-
lum fold continues anteriorly around the paracone. Mis a small peg-like transverse
tooth, with a single transversely flattened root: the crown is worn but enough remains
to discern the presence of a protocone and larger paracone, beyond which probably
lay a small parastyle.

The crowns of P*+4 and the paracone of M1! are worn flat and the shearing meta-
cones of M!+? show evidence of much wear: neither the protocone on P* nor M?
shows any wear, suggesting a deep or very reduced talonids on the lower molars.

REMARKS. The strongly sectorial M1*2, together with the prominent protocone
suggest a degree of evolution comparable with Pterodon. The genus has not the
advanced specialization of Hyaenodon, nor the more tubercular features of A pterodon.
A picture emerges of Metapterodon species as medium sized hunters comparable with
foxes, as opposed to the heavier built and larger Pterodon species, more comparable
to the hyaenas.

There are no features on which the S.W. African and Rusinga specimens can be
seen to differ. The table of measurements for both specimens shows the close
similarity in size: (the figures for the S.W. African specimen are taken from Stromer
(1926): in this the Mis missing and the P* is rather narrower).

On specimen CMF.4066a all three teeth are broken (P4-M?2), but enough of M? is
preserved to make identification certain. The only difference from the specimen
described above is a slightly greater size; this however is small and not considered
to be of taxonomic importance in view of the proximity of Karungu and Rusinga,
and the general resemblance of their mammal faunas.

Metapterodon zadoki sp. nov.
(Pl. 4, fig. 2; Text-fig. 29)
Diacnosis. Slightly larger than the type species ; upper molars robust with strong
shear, parastyle absent from M1*?, protocone very reduced on M1*?.
The specific name pays tribute to Zadok, the keen-eyed Luo collector on Rusinga.

MIOCENE CARNIVORA OF EAST AFRICA 271

HorotyPe. M.19094. Right maxillary fragment with M12. Rusinga Island,
Lake Victoria, Kenya.

DescripTIon. The holotype is the only known specimen of the species. None
of the maxilla save that which supports the teeth is preserved. A posterior fragment
of P*is present. M!has a high conical paracone and trenchant metacone, both of
about equal width; the shear of the metacone is continued onto the paracone,
thus providing a large shearing surface: there is no parastyle, but a prominent
external cingulum wraps round the anterior margin of the tooth: the vestigial
protocone is little more than a low enamel-capped root placed far anteriorly, clear
of the extended shearing metacone-paracone. M7? is an enlarged edition of M}, with
which it corresponds in all details.

RemMARKS. The most notable differences between M. zadoki and M. kaiseri relate
to the carnassial specialization. M. zadoki is the more advanced, having a shear
extending onto the paracone, reduced protocone and being without parastyle:
this is a stage of development which could easily be derived from M. kaisert.

TABLE 4

Measurements of Metapterodon species (in mm.)

Metapterodon | Metapterodon | Metapterodon | Metapterodon | Metapterodon

Raiservi kaisert kaisevt zadokt biincisivus
Stromer 1926 CMF. 4038 CMF.4066a M.19094 Filhol 1876
S.W. Africa Kenya Kenya Kenya Phosphorites

Holotype Holotype du Quercy

Holotype
py a—p 8 7:8 — 12:0
trs 3 49 5°4

ipy a—p 75 8-6 9:0.

trs 6°5 7°4 8-2 IIo
Mt a—p 9 9°4 9°4. 15°0
trs 7 8-5. JF TIO)
M2 a—p I0'5 10°6 I2°3 16:2
trs 10°5 8°5 9°33 14°6
M3 a—p 2 2:8 — 4:8
trs eh 1g 6-4 12‘0

*approximate

272 MIOCENE CARNIVORA OF EAST AFRICA

Genus PTERODON de Blainville 1839

Diacnosis. Hyaenodontine with M3; P?—M? rapid increase in size; premolars
short and high; M+*? with small protocone, parastyle large; lower molars with strong
paraconids, talonids reduced; molars strongly trenchant: infra-orbital foramen above
BS

TYPE SPECIES. Ptevodon dasyuroides de Blainville from the Lower Oligocene of
the Phosphorites du Quercy, France. Also recorded from the same horizon in several
parts of France, Germany and the Isle of Wight.

The following species have also been described :—

P. grandis (Cope 1885). Lower Oligocene, White River Beds, Saskatchewan,
Canada.

P. magnus Rutimeyer (1891). Middle Eocene, Switzerland.

P. africanus Andrews (1903). Lower Oligocene, Fayim, Egypt.

P. leptognathus Osborn (1909). ,, at

P. phiomensis Osborn (1909). _,, “ ee He

P. hyaenoides Matthew & Granger (19250). Upper Eocene, Shara Murun,
Mongolia.

P. californicus Stock (1933). Upper Eocene, California.

” ”

REMARKS. ALl species are strikingly similar and vary mainly in size. None is
plentiful or fully known. Three other species described from Europe, P. parisiensis
de Blainville (1841), P. cuvierr Pomel (1847b) and P. coguandi Pomel (1853), are
considered synonyms of P. dasyuroides. P. biincisivus Filhol (1876) is discussed
above and considered to be a species of Metapterodon.

Pterodon africanus Andrews

(Pl. 4, fig. 3; Text-figs. 30-32)
1903 Ptevodon africanus Andrews: 342, text-fig. 3.
Di1AGNosis. Species distinguished from others in the genus on size; all except
P. grandis and P. nyanzae are smaller. P. grandis is two-thirds as large again;
P. nyanzae lacks an anterior keel on P* and Mt}.

HotoryPe. M.8503. Right ramus of mandible with P, ,, M,_, from the fluvio-
marine beds, Lower Oligocene, north of Birket-el-Qurun, Fayim, Egypt (Andrews
1906: 220, pl. 19, fig. 3).

OTHER MATERIAL. In addition to the holotype there exist skulls and man-
dibles described by Andrews (1906) and Schlosser (1911).

Further specimens from Uganda and Kenya are referred to below.
M.1gogo. Left maxilla with P4, M!?, Napak I, Karamoja, Uganda.
CMF.4024. Right P4, Rusinga Island, Kavirondo Gulf, Kenya.

DESCRIPTION. On the new maxilla from Napak the crowns of the teeth are
broken but otherwise in good condition. On P* the strong paracone has a posterior
keel and beyond a keeled accessory cusplet; the protocone has a very heavy root,

273

MIOCENE CARNIVORA OF EAST AFRICA

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274 MIOCENE CARNIVORA OF EAST AFRICA

but is not elevated into a cusp and forms instead an internal shelf; the parastyle is
broken externally and is slightly smaller than the posterior cusplet. M1! is much
larger than P4; the small protocone is placed very anteriorly and its border projects
beyond that of the smaller parastyle: the large paracone is characterised by the
presence of a strong external groove and weak internal groove, posterior to which
the cusp is trenchant internally; (the groove is indicative of the fusion of the paracone
and metacone): a notch separates the paracone from the trenchant blade of the
elongate metastyle. Mis a massive tooth with a high paracone, keeled posteriorly
to meet the long trenchant metastyle; the parastyle is slightly larger than the proto-
cone, which arises anteriorly, well removed from the paracone; the paracone-meta-
style blade lies at about 20° to the longitudinal axis of the jaw. The small alveolus
denotes a vestigial transverse M°.

REMARKS. The similarity of the East African material to the Fayim specimens
is so close and the differences so trivial, I can find no case for separating them into
different species. The size of the Faytm and Napak teeth are very similar, though
few measurements in the table are precise due to damage affecting nearly all teeth.
The Faytm skull (C.10192) is rather lighter in build than the Napak maxilla, while
the holotype jaw has a massiveness more akin to the new find. These differences
are trivial and amount to no more than individual variations; possibly the holotype
and the Napak specimen are male and the Faytim skull female.

The external groove on the paracone-metacone of M! is barely noticeable on the
Faytm skull, but distinctive on the Napak maxilla: otherwise there are no distinguish-
ing features. The Rusinga premolar tooth, CMF.4024, referred to the species is a
very worn and isolated P?.

Considerable interest attaches to the specific linkage of East African sites with
Fayum, since the Faytim stratigraphy is well dated and the hyaenodontids appear
to be good stratigraphic indicators. This aspect is discussed at the end of the paper.

Pterodon nyanzae sp. nov.
(Text-figs. 33-35)
DiaGnosis. Species larger than P. africanus and smaller than P. grandis. Dis-
tinguished from P. africanus by presence of anterior keel on P4 and M1.
Name derived from Nyanza, the province of Kenya in which the species occurs.

HototyrPe. M.rgogr. Isolated right P4 from Ombo, Kavirondo Gulf, Kenya.

PARATYPES. In addition to the holotype, the type locality has yielded two para-
type specimens M.19092 isolated left P4, broken and M.19093 isolated right M1},
broken.

Another specimen CMF.4007, a very broken left P4 from Rusinga Island, site 3,
is also referred to the species. A right M? (UMP 64.33) is recorded from Napak II A.

MIOCENE CARNIVORA OF EAST AFRICA 275

Description. The holotype is a nearly complete right P*. The tooth has three
roots, anterior, posterior and internal; all are heavy straight-sided roots,the internal
the largest and the anterior the smallest. The tooth has a large central conical cusp,
accessory cusplets and an internal shelf. The apex of the central cusp is worn flat and
the thick enamel is elevated into a ridge anteriorly and posteriorly, the posterior
ridge being the higher. The anterior accessory cusplet is much worn by occlusion
with P, and the posterior cusplet is strongly keeled: the internal sloping shelf is
broad and without any cusp development.

34 35

Fics. 33-35. Ptevodon nyanzae sp.nov. Right P4. (33) Occlusal aspect.
(34) Medial aspect. (35) Lateral aspect. Holotype (M.19091), Ombo. xT.

The paratype M.1g092 is a left P4 and although part of the internal shelf and all
the roots are missing, it is an exact mirror image of the holotype, displaying the same
degree of wear. The paratype M.19093 is a right M! with only the anterior half pre-
served: the tooth is three rooted and probably the anterior root is the largest. The
paracone and metacone are completely fused though there remains a distinct groove
externally on the conical cusp, truncated by wear.

CMF.4007 consists only of the posterior half of the central cusp and the posterior
keeled cusplet. In size and character there is nothing to distinguish it from the two
P* teeth described above.

REMARKS. The three teeth from the same site may be from the same individual,
judging from the degree of wear on the crowns. The table of measurements shows
they are considerably larger than P. africanus teeth, much more so than would be
expected by individual variation. The well marked anterior keel on both P4 andM!
clearly distinguishes these teeth from the P. africanus specimens of Faytm and of
Napak.

276 MIOCENE CARNIVORA OF EAST AFRICA
TABLE 5
Measurements (in mm.) for Pterodon africanus

and Pterodon nyanzae

ps M1 M2
P. africanus a—p 25 29 36
C.10192 trs 20 20 23
Fayim, Egypt
P. africanus a—p 26 32 38
M.19090 trs 22 Pit 29
Napak, Uganda
P. africanus a—p 25
CMF .4024 trs 22
Rusinga, Kenya
P. nyanzae
(Holotype.) a—p 30
M.19091 trs 24
Ombo, Kenya
P. nyanzae a—p 29
M.19092 trs 24
Ombo, Kenya
P. nyanzae a—p —
M.19093 trs 28
Ombo, Kenya

Genus LEAKITHERIUM nov.

Dracnosis. Hyaenodontine without M3; M1? highly sectorial, protocone greatly
reduced on M?; molars with connate paracone and metacone and shearing metastyle;
P4 with protocone and prominent parastyle, central paracone, metacone and trenchant
metastyle.

TYPE SPECIES. Leakitherium hiwegi sp. nov.

Leakitherium hiwegi sp. nov.
(Pl. 4, figs. 4, 5; Text-figs 36, 37)
Diacnosis. As for genus. Species about size of leopard.

HototyrPe. M.19083. Left maxillary fragment with M!+? from Rusinga Island,
Lake Victoria, Kenya. The only species.

PARATYPE. CMF.4025. Left maxilla with M!and P4 from Rusinga Island, site 3,
Lake Victoria, Kenya. This is the only other specimen of the species.

DESCRIPTION. None of the skull other than the bone surrounding the teeth is
known. The holotype has the bone preserved to the level of the orbit and the begin-

MIOCENE CARNIVORA OF EAST AFRICA 277

ning of the jugal is discernible. P* has high central cusp and prominent protocone
opposite: the parastyle is smaller than the protocone: the tooth is not well preserved
posteriorly but the metacone probably formed a low cusp followed posteriorly by a
trenchant metastyle. M1is larger than P*: the metacone is connate with and slightly
larger than the paracone; the cusps are divided buccally by a groove and are sectorial
on the inner side. The protocone is placed anteriorly, level with the paracone: the
parastyle is displaced buccally and much smaller than on P?*: the trenchant meta-
style continues posteriorly the shear of the metacone. M? is about the same size
as M! and structurally similar, save that the protocone is very reduced and the

parastyle absent.
) ‘

Re Z a i

Z
—
i
Sy
SOY

Fics. 36, 37. Leakitherium hiwegi gen. et sp. nov. (36) Left maxilla with M! ?, occlusal,
medial and lateral aspects. Holotype (M.19083), Rusinga Is. (37) Left maxilla with
P4, M!, occlusal, medial and lateral aspects. (CMF .4025), Rusinga ls. x1°5.

Remarks. The presence of two carnassial upper molars and the absence of M?
places the species immediately in the Hyaenodontinae. Within this subfamily only
Hyaenodon is known to lack M? and on Hyaenodon the protocones and talonids are

278 MIOCENE CARNIVORA OF EAST AFRICA

also lacking. Leakitherium displays the clear tendency to greater carnassial efficiency
as seen in the morphological series A pterodon—Pterodon—L eakitherium—H yaenodon.
The strongly sectorial molars, with cutting plane directed anteroposteriorly and not
transversely, are characters found elsewhere among the Hyaenodontidae only in
Pterodon and Hyaenodon. The loss of M? in Leakitherium without loss of protocones
save reduction on M2, implies a less advanced specialization than in Hyaenodon.

Measurements (in mm.) for Leakitherium hiwegi

CMF.4025 M.1908 3
1D M1 M1 M2
ant-post ? 16°4 16:0 16°5 16°0
lat 113 14°3 6:0 ? 13°0

Genus HYAENODON Laizer & Parieu 1838

Driacnosis. Dental formula 34-42; M? with shallow groove on completely
connate paracone and metacone; molars without protocone; metastyle strongly
elongated, especially on M?. Main carnassial pair M2, with M3 as accessory carnas-
sials. M, without talonid, M,,. with or without vestigial talonid.

TYPE SPECIES. Hyaenodon leptorhynchus Laizer & Parieu.

STRATIGRAPHIC RANGE. Upper Eocene to Upper Oligocene, Europe; Upper
Eocene to Middle Oligocene, Asia and N. America; Lower Oligocene to Lower
Miocene, Africa.

The following species have been attributed to the genus:—

Europe America

N.
Hi. leptorhynchus Laizer & Parieu 1838 H. horrvidus Leidy 1853
H. brachyrhynchus de Blainville 1842 H. cruentus Leidy 1853
H. vulpinus Filhol 1876 H. crucians Leidy 1853
H.. compressus* Filhol 1876 H. mustelinus Scott 1894
H. minor Gervais 1848-52 H. paucidens Osborn & Wortman 1894
H. bavaricus Dehm 1935 H. montanus Douglass 1901
H. aimi Cooper 1926 H. leptocephalus Scott 1887
FH. pavisiensis Gervais 1848-52 HZ, vetus Stock 1933
H. martini Depéret 1917 H. minutus Douglass 1901
H. Cayluxi Filhol 1876
HZ. dubius* Filhol 1872 Asia
FH. vequieni Gervais 1846 H. pervagus Matthew & Granger 1924
H. aymardi* Filhol 1881 H. eminus Matthew & Granger 19254
H, herberti Filhol 1876 H. yuanchensis Young 1937
H. milloquensis Martin 1906
Hi. filholi Schlosser 1887 Africa
FH. ambiguus* Martin 1906 H. brachycephalus Osborn 1909
H. gervaisi Martin 1906 H. andrewsi sp. nov.
FH. laurillardi Pomel 1853 H. matthewi sp. nov.
Hi. exiguus Gervais 1876 H. pilgvimi sp. nov.

*species also occur in Asia

MIOCENE CARNIVORA OF EAST AFRICA 279

Remarks. No genus among the hyaenodonts is in so much need of revision as
Hyaenodon. No less than 33 species are recorded in the literature and the genus
has a much greater stratigraphic range than any other in the subfamily. A survey
of the species makes it clear that either there is a very wide range of variation within
the genus or several genera are involved, or possibly both factors operate together
to produce the present chaotic assemblage of forms. The diagnoses of species within
the genus rest almost entirely on size differences; morphological characters used
have been found to be inconstant. Much of the known material comprises mandibular
remains and in an attempt to unravel the species I plotted the distribution of the
following six characters :—

a. Presence or absence of Pj.

b. P, with r or 2 roots.

c. Mental foramina below P,, between P, and Pg, or below P..

d. Presence or absence of buttress on antero-external margin of M..

e. Presence or absence of trace of talonid on Mg.

f. Size relation of protoconid to paraconid.

P, is almost always present and usually has two roots. There is invariably a
mental foramen below P,, frequently below P, and sometimes one or more either
below P, or between P,and P,. On M. the buttress is highly variable, being present
on some individuals and absent from others of the same species: it is more usually
present than absent. Relatively few specimens show trace of a talonid on Mg. The
protoconid tends to be larger than the paraconid, sometimes by a considerable margin,
and occasionally the two are almost equally long. None of these characters, either
singly or in combination, can be used for specific determination. Size is a not very
satisfactory criterion on which to base a diagnosis; there is probably a wide range
within each species, if only this could be checked, and much overlap.

Nine North American species are described, ranging from the very large H.
horridus to the small H. mustelinus. Three species are recorded from Mongolia and
China and one from the Faytm of Egypt. The remaining 20 species are European
and of these 4 also occur in Asia. Many are poorly known and synonyms are inevit-
ably rampant. The stratigraphic distribution in Europe illustrates an Upper Eocene
group of species and a Middle-Upper Oligocene group. The Upper Eocene group has
a possible forerunner in the Middle Eocene, Propterodon: this form from Egerkingen
is poorly known but may be a link in the line from proviverrines to hyaenodontines.

In the absence of a full scale revision of the genus I find it best to make a com-
promise. The African species appear to have one important character in common
which is rare if not truly absent from all others, and on this basis they are grouped
into a new subgenus. When more material is available, it will probably be possible
to elevate this taxon to generic rank.

280 MIOCENE CARNIVORA OF EAST AFRICA

Subgenus ISOHYAENODON nov.

D1aGnosis. Hyaenodon species in which the protoconid and paraconid of Mg are
approximately equal in length.

Type SPECIES. Hvyaenodon (Isohyaenodon) andrewst sp. nov.

In addition to the type species, the following are included in the subgenus
Isohyaenodon: Hyaenodon brachycephalus Osborn, H. matthewt sp. nov., and H.
pilgrimt sp. nov. The three new species, H. andrewsi, H. matthew and H. pilgrim
are all smaller than H. brachycephalus, and H. pilgrimz is by far the smallest known
Hyaenodon species.

TABLE 6

Distribution of Hyaenodon species

EUROPE AFRICA ASIA N. AMERICA
LOWER andrewst
MIOCENE matthew
pilgrim
UPPER milloquensis
OLIGOCENE bavaricus
leptorhynchus
gevvaist
MIDDLE leptovhynchus pervagus mustelinus
OLIGOCENE gevuaisi aymardi paucidens
brachyrhynchus ambiguus leptocephalus
vulpinus compressus horvvidus
laurillardi dubius cruentus
exiguus CYUCIANS
compressus
martini
cayluxt
dubius
ambiguus
fitholi
LOWER aymardt brachycephalus yuanchensis horvidus
OLIGOCENE andrewst cruentus
crucians
montanus
minutus
UPPER aim eminus vetus
EOCENE minor
parisiensis
vequient

hevbert1

MIOCENE CARNIVORA OF EAST AFRICA 281

Hyaenodon (Isohyaenodon) andrewsi sp. nov.
(Pl. 4, fig. 6; Text-figs. 38-40)

Dracnosis. Jsohyaenodon of about the same size as H. minor. M, with vestigial
talonid.

The trivial name is a tribute to C. W. Andrews (1866-1924), a profound student of
fossil mammals who made a singular contribution to our knowledge of the Faytim
faunae.

Horotyre. M.15048. Right mandibular fragment with M, 5. From Ombo,
Kavirondo Gulf, Kenya.

ADDITIONAL MATERIAL. In addition to the holotype the following are referred to
the species:

CMF.402t Right mandible with P,,,, Mo.5, alveoli of C, Py.5, Mj.
Moruorot South, Northern Frontier District, Kenya.

CMF.4022 Right mandibular fragment with M, and alveoli of My,9.
Songhor, Kavirondo Gulf, Kenya.

CMF.4023 Broken left M,. Rusinga Island, site 3, Kavirondo Gulf, Kenya.

C.8812-13. Fragment of right mandible with M,: from Fluviomarine beds,
Birket-el-Qurun, Fayim, Egypt.

DeEscripTIOn. The holotype is much broken and little of the mandible remains
other than that part enclosing the tooth roots, but the surviving parts give the
impression of robustness.

M, is small and much worn, in contrast to all other teeth which are unworn, M.
being not even fully erupted. On M, the protoconid is rather larger than the para-
conid: the summit of the protoconid is truncated by wear and the paraconid appears
to have been damaged during life since on the broken anterior surface the fracture
edges are not fresh; these two cusps are separated by a shallow cleft, and the tren-
chant labial face is longitudinally aligned: the small low talonid slopes antero-
medially. M, is much larger than M,; the paraconid and protoconid form good
shearing facets; the talonid is proportionately smaller than on M, and a small
buttress is present near the base of the antero-labial edge of the paraconid. The
large M. is almost fully erupted and completely unworn; the paraconid is as broad
as but not as high as the protoconid and the cleft which separates them extends
almost to the base of the tooth; the carnassial shear is only slightly oblique and a
small buttress is again present on the outer edge of the paraconid: a vestigial talonid
is present on the postero-internal border.

An anterior mandibular fragment with three premolars has been glued to the
holotype described, although its true association with this is dubious. There is very
little actual bone contact and this does not form a neat join. I suspect that at best
this is an anterior fragment with a middle section between the two parts missing, or
else it has nothing to do with H. (I.) andrews. This second fragment, if it truly

282 MIOCENE CARNIVORA OF EAST AFRICA

Fics. 38-40. Hyaenodon (Isohyaenodon) andvewsi sp. nov. Right mandible with M,-,.
(38) Occlusal aspect. (39) Lateral aspect. (40) Medial aspect. Holotype (M.15048),
Ombo. X1°‘5.

belongs to the same individual, may represent three milk premolars and part of the
alveolus of the canine; the premolars are small in comparison with the molars
of the holotype. The first is a small two-rooted tooth with posterior accessory cusp
lying very close behind the canine. The second is similar but slightly larger. The
third premolar is more robust with high pointed central cusp and low posterior cusp;
a cingulum is present anteriorly and postero-internally. The first two premolars
appear to belong to the same dentition; compared with the permanent molars, their
small size suggests milk teeth; their position with respect to the canine makes it
likely that they are DP, 9, though it is possible they could be DP, 5, allowing for a
very small first milk premolar, or even its absence.

MIOCENE CARNIVORA OF EAST AFRICA 283

The second mandible, from Moruorot, is less broken but fewer teeth are present.
The jaw is long, shallow and strongly built; anteriorly there is a long symphysis and
posteriorly the mandibular foramen issues well behind M,. Mental foramina are
present under P, and Py. The angular process of the jaw is stout and dorso-ventrally
flattened; the masseteric fossa deep. The posterior part of the canine alveolus is large
and ovoid in section. P, and P, are absent: P, was small and apparently single
rooted, and P, much larger and two-rooted, the posterior root being preserved in the
alveolus. The crown of P,is much worn and broken: it appears to have had a conical
central cusp and small posterior accessory cusp. P, is complete, the tip of the cusp
is somewhat worn and its anterior and posterior borders become slightly concave
towards the base, with a prominent posterior cingulum around the accessory cusp.
M, is missing and M, broken with only the base remaining; this indicates a strong
paraconid-protoconid shear, slightly oblique, behind which lay a small antero-
medially sloping talonid. Mg, is complete and indistinguishable from that on the
holotype; the tooth is fully erupted in a crowded jaw, and lies obliquely resulting in
a transverse shear.

Specimen CMF .4022 contains a Mg, with broken protoconid, but otherwise little
worn. The fully erupted tooth in situ has an oblique shear, which runs at 40° to the
longitudinal axis of the tooth row. CMF.4023 comprises a very broken tooth stump
which is referred to the species on size, absence of talonid and metaconid, and
obliqueness of shear.

Andrews (1906) referred a specimen (C.8812-13) from the Fluvio-marine beds
north of Birket-el-Qurun in the Faytim, to the genus Hyaenodon. On page 219 he
described this right mandibular fragment and associated Mg. The tooth is structurally
indistinguishable from the holotype described above and nearly the same size.
Nothing debars the specimen from inclusion in the species H. andrewst.

Hyaenodon (Isohyaenodon) matthewi sp. nov.
(Text-figs. 41-43)

Diacnosis. Isohyaenodon of rather smaller size than H. (I.) andrewsi and Ms
with less oblique shear; details in accompanying table.

Trivial name is a tribute to W. D. Matthew, a British geologist whose signal
contributions to mammalian palaeontology are unsurpassed.

HoLotyPe. M.19098. Left mandibular fragment with M, and broken M, from
Songhor, Kavirondo Gulf, Kenya.

OTHER MATERIAL. The following additional specimens are referred to the species:

CMF.4060 Left M, from Rusinga Island, Kavirondo Gulf, Kenya.
CMF.4061 Right M, from Rusinga Island, Kavirondo Gulf, Kenya.

DEscCRIPTION. A fragment of mandible surrounding M, is preserved. The build
of the jaw is lighter than in H. (I.) andrews; the masseteric fossa is pronounced and
a groove is present on the lower anterior face of the coronoid crest. M4, is similar to
that on H. (I.) andrews: but proportionately smaller. The protoconid is higher than

284 MIOCENE CARNIVORA OF EAST AFRICA

42 Al 43

Fries. 41-43. Hyaenodon (Isohyaenodon) matthewi sp. nov. Left mandible with M,-5. (41)

Occlusal aspect. (42) Medial aspect. (43) Lateral aspect. Holotype (M.19098),
Songhor. XI.

the paraconid and the shear plane convex outward; the obliqueness of shear is 20°,
that is much less than in H. (I.) andrewsi. A vestige of the talonid is present and on
this unworn tooth a very minute prong is visible on the internal cingulum at about
the place where a metaconid would arise if one was present. The small talonid of
M, abuts against the paraconid of Mg, the alignment being maintained by a small
buttress; no more of M, is preserved on the holotype.

On a left M, (CMF.4060) from Rusinga the protoconid is decidedly higher than the
paraconid and a small talonid is present; the shear plane is convexly curved and not
as oblique (at 15°) as that of Ms. CMF.4061 is an isolated right Mg, indistinguishable
from the holotype, but slightly broken on the cusp tips.

Hyaenodon (Isohyaenodon) pilgrimi sp. nov.

(Text-figs. 44-49)

D1aGnosis. Small species of Isohyaenodon,; about half the size of H. filholi and
H. mustelinus.

The trivial name is a tribute to G. E. Pilgrim (1874-1943), an outstanding scholar
of European and Asiatic Tertiary mammals.

HoLotyPe. M.1g100a-c. Pair of complete mandibles with posterior fragment of
skull and 7 cervical vertebrae; from Rusinga Island, Kavirondo Gulf, Kenya.

OTHER MATERIAL.
CMF.4062 Right mandible with P,, M,,5. Rusinga Island, Kavirondo Gulf,
Kenya.
CMF.4063 Left mandible fragment with P,,,, M,. Rusinga Island, Kavi-
rondo Gulf, Kenya.
CMF.4064 Upper left M!. Songhor, Kavirondo Gulf, Kenya.
CMF.4065 Left lower canine. Rusinga Island, Kavirondo Gulf, Kenya.

DESCRIPTION. This species is about the same size as the polecat, Mustela putorius.
The two mandibles are complete though separate and only the incisors and P, are
missing. The mandible is about the same size as that of a pine marten; it is lightly
built with a long symphysis. The coronoid is high and the crest rounded. The
condyle is transverse, well rounded and on a level with the tooth row; below is the

MIOCENE CARNIVORA OF EAST AFRICA 285

short stout angular process. The masseteric fossa is not deep and the mandibular
foramen issues just posterior to Mg. On the labial side of the jaw there is a row of
mental foramina, below Py, P35, M, and Mg.

C HR@aseeo -

Fies. 44-46. Hyaenodon (Isohyaenodon) pilgvimi sp.nov. Partial reconstruction from right
and left mandible with C, P,-M,. (44) Occlusal aspect. (45) Medial aspect. (46)
Lateral aspect. Holotype (M.19100), Rusinga Is. x2.

No incisors are known and from the proximity of the canine to the symphysis they
must have been very small. The canine is slightly flattened on the medial side and
tapers upward with a gentle curve backwards. P, is absent on both sides, and was
apparently a small single-rooted tooth. P, is two-rooted, the cusp is centred over
the anterior root and it slopes backward to a small accessory cusp over
the posterior root. On P, the cusp is centrally placed, with a longitudinal keel
running anteriorly to a slight cingulum and posteriorly to a small accessory cusp.
P, is similar structurally to P, only slightly larger. M, is broken on both sides, but
was clearly a small obliquely shearing molar, with protoconid rather larger than the
paraconid and a vestigial talonid. M4, is similar to M, but considerably larger and
Mgis slightly larger than My. On M, the well developed shear is oblique, the proto-

286 MIOCENE CARNIVORA OF EAST AFRICA

conid is higher than the paraconid and the only trace of the talonid is a slight bump
of enamel on the posterior edge of the protoconid. A minute buttress is present on
the antero-labial edge of M, and Mg. A left M1 from Songhor is referred to the
species.

L 2 | )

48 47 49
Fics. 47-49. Hyaenodon (Isohyaenodon) pilgvrimi sp. nov. Left M1. (47) Occlusal
aspect. (48) Lateral aspect. (49) Medial aspect. (CMF.4064), Songhor. x4.

Together with the two mandibles, the posterior part of the brain-case and seven
cervical vertebrae are preserved; all are broken and partly crushed, particularly the
posterior part of the skull, so that of this no details can be discerned.

In size and build the cervical vertebrae approach those of Mustela putorius, the
polecat. The atlas vertebra possesses a fairly wide dorsal and narrow ventral arch,
the latter with well developed longus colli tubercle. No rectus capitus posticus
minor muscle scar is visible on the anterior face of the dorsal arch. The wings, though
broken, can be seen to be light and did not project far laterally, no more than one
third the width of the neural arch. The oblique foramen issues dorsally behind the
cotylar process. The vertebrarterial canal is very short, the ventral and posterior
openings being close together at the base of the wing. The axis is closely comparable
with that of the polecat, and differs from it only in having light non-tuberculate
posterior zygapophyses and the posterior extension of the spine beyond the neural
arch, though broken, was probably thinner and shorter.

The remaining cervical vertebrae are partially crushed, especially on lateral and
ventral faces. Their dorsal surfaces reveal that the neural spines were vestigial on
third to fifth inclusive; the sixth cannot be seen and on the seventh a small spine
was present.

The close comparison in size and proportions of the jaws and vertebrae with those
of the polecat is instructive. In appearance Isohyaenodon pilgrinu must have looked
very like a polecat, but perhaps without the latter’s strength and agility. There is a
consistent weakness in the development of dorsal musculature, a feature found in
modern aquatic carnivores.

REMARKS ON ISOHYAENODON SPECIES

The most striking thing about the three new species is their similarity to each other
and difference from other Hyaenodon species. Secondly the Isohyaenodon material
falls readily into three groups on basis of size differences. The only other described
species from Africa, H. brachycephalus can be included in the subgenus Isohyaenodon
on the basis of near equality of paraconid and protoconid on Mg. Its size is greater
than any of the three species described above, and it possesses a relatively short
mandible compared with others in the subgenus. The distribution of this character
of mandibular length is another variable in the genus, which on available material,
does not form any meaningful pattern.

287

MIOCENE CARNIVORA OF EAST AFRICA

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288 MIOCENE CARNIVORA OF EAST AFRICA

Suborder FISSIPEDA Blumenbach
Superfamily CANOIDEA Simpson
Family CANIDAE Gray

Diacnosis. Arctoidea, with a moderately high skull, brain-case not expanded;
auditory bulla originally small, remote from the paroccipital process, as in Amphi-
cyoninae, but in most lineages ultimately becoming enlarged and inflated and
brought into contact with the paroccipital process; alisphenoid canal present.
Dental formula 3-+-+-2-~: P* elongate, protocone prominent in early genera, later
much reduced; M1! 3- or 4-tubercular, often with intermediate cusps, always broader
than long, becoming progressively larger along many lines; M? similar, only very
exceptionally lost; M® present in some early genera, and in most of the Amphi-
cyoninae; lost later; M, with metaconid strong in primitive genera and in the
Amphicyoninae, progressively weaker along other lines; talonid with trenchant
hypoconid; entoconid present either as a ridge, shelf, or tubercles in the early genera,
and retained on most lines; M, long; Mg only exceptionally lost in some highly
specialized genera; digitigrade; primitive members with five digits, later forms with
first digit both in manus and pes reduced. [after Pilgrim 1931].

REMARKS. About 60 genera of fossil canids are recognised and in addition there
are 12 living genera. The classification of these numerous genera within the family
Canidae presents many difficulties and numerous attempts have been made. None
is completely satisfactory. The relative abundance of fossil forms increases rather
than lessens the difficulties. Simpson (1945) has stated of the Canidae that their
“status as a single family ...can be upheld without serious doubt” and then adds
“the whole group is extremely polyphylectic’—two statements which appear
irreconcilable. It is beyond the scope of this work to attempt yet a further revision
of the classification (a task begun by Hough (1948) for American fossil genera and by
Hiirzeler (1944) and Ginsburg (1955) for some of the European genera): It will
suffice here to adopt the status of the subfamily Amphicyoninae as defined below,
without reference to its relationship to other subfamilies.

Subfamily AMPHICYONINAE Trouessart

D1acnosis. Canidae, with auditory bulla small, little inflated, remote from the
paroccipital process; mastoid process prominent and broad; molars progressively
enlarged, premolars and carnassials progressively reduced; upper molars trituber-
cular, with broad postero-internal shelf; M? and M, present in most forms, but lost
in advanced members; P* with progressively reduced protocone; M, generally with
metaconid, talonid with hypoconid and ridged entoconid. M, with bicuspid triginid
and crested talonid; limb bones massive; humerus with entepicondylar foramen;
manus and pes 5-dactyl. {after Pilgrim 1931.|

REMARKS. Only one genus (Wammocyon Loomis 1936) has been added to the
subfamily since Pilgrim (1931) discussed its status. Arambourg (1961) described a
very worn mandibular fragment from Gebel Zeltan in Libya as A frocyon, a new genus

MIOCENE CARNIVORA OF EAST AFRICA 289

of amphicyonid. Until more material is available nothing useful can be added to this
statement. In the confusion that exists regarding the affinities of the canid genera,
it would be futile to attempt a concise formulation of any one subfamily. The new
genus described below is included with the Amphicyoninae on the basis of its close
parallels to Amp/icyon, rather than on a rigorously definitive basis. When canid
systematics are usefully revised, the two genera will probably be placed close
together.

Genus HECUBIDES nov.

Diacnosis. Amphicyonine with long face; dental formula 2:+4:2; anterior

premolars well spaced; P* reduced in comparison with molars; protocone not so
anteriorly placed as in Amphicyon and parastyle absent; carnassial blade not
oblique; M! only slightly larger than M2; both sub-triangular and transverse width
greater than length, lunate protocone and extensive internal cingulum more asym-
metrical and smaller on M!; paracone and metacone equal on M2 and metacone only
slightly smaller than paracone on Mt. M? small: M, with well developed trenchant
hypoconid and ridged entoconid.

TYPE SPECIES. Hecubides euryodon sp. nov.

In addition to the type species a second new species, H. macrodon, is described
below and two others are referred to the genus, H. americanus (Wortman) and H.
lemanensis (Pomel).

Remarks. The probable affinities of the new genus are described below in the
remarks on the type species. It is quite distinct from both the European Amphicyon
and the American Daphoenis and appears to represent a separate stream of develop-
ment.

Hecubides euryodon gen. et sp. nov.
(Pl. 5, fig. 1; Text-figs. 50-54)

Diacnosis. Medium sized Hecubides species: M! about 18 mm. transversely and
15 mm. longitudinally: M1 with strong internal cingulum, no crenulation on either
protocone or internal cingulum of either M1! or M?.

DERIVATION OF NAME. Generic name from Hecuba, princess in Greek mythology
who was changed into a stone dog. The trivial name is from the Greek ewrys, wide
or broad.

HorotyPe. M.19084. Maxillary fragment with P?+4, M!+? and alveoli of P? and
M? on both sides.

Locatity. Locality I, Napak, Karamoja, Uganda.

PARATYPE. In addition to the holotype, the type locality has yielded an isolated
right M, (M.19085).

290 MIOCENE CARNIVORA OF EAST AFRICA

ADDITIONAL MATERIAL. The following specimens are referred to the species :—

M.14313 Right M}, broken Koru, Kavirondo Gulf, Kenya.

M.19099 Left M, Locality I, Napak, Karamoja,
Uganda.

CMF.4026 Right M, Songhor, Kenya.

CMF.4027 Right M, Rusinga Island, Kavirondo Gulf,
Kenya.

CMF.4067 Left M,, talonid only Rusinga Island, Kavirondo Gulf,
Kenya.

CMF.4068 Left M?, protocone only Mfwanganu Island, Kavirondo
Gulf, Kenya.

CMF.4069 Left M,, trigonid only Rusinga Island, Kavirondo Gulf,
Kenya.

H.M.V.5830 Left M, Locality IV, Napak, Karamoja,
Uganda.

UMP64.32 Right M, Locality I, Napak, Karamoja,
Uganda.

DEscrIPTION. The holotype consists of an incomplete maxillary dentition
together with the adjacent parts of the maxillae bones. P4, M1*? are preserved on
both sides: P? is complete on the right side, broken on the left: parts of the alveoli
of P* and M® can be distinguished. The dentition gives an overall impression of
robustness; the teeth have thick enamel, low cusps and are relatively wide.

The premolar teeth are well spaced and indicate a relatively long but strong jaw.
Nothing anterior to the alveolus of P? is known; of this tooth only the posterior root
cavity remains and it was presumably a smaller version of P? which is a single cusped
birooted tooth, narrow and elongated. In P‘ the fully sectorial paracone-metastyle
blade is directed antero-posteriorly; the paracone is higher and larger than the
metastyle and the two are separated by a narrow cleft: no parastyle is present,
though a slight bump can be detected on the ridge of enamel which falls anteriorly
from the summit; the protocone is small, low, close to the paracone and lies midway
between the paracone summit and its anterior border. M!? is a large triangular
tubercular tooth, with its transverse width greater than its length; the paracone is
slightly larger than the metacone and both have prominent antero-posterior keels.
The crescentic protocone, separated by a wide basin from the paracone and meta-
cone, is slightly asymmetrical, being shorter but heavier anteriorly; lingual tothe
protocone is a thick cingulum, and a narrow cingulum runs buccal to the paracone
and metacone. M? is only slightly smaller than M! and structurally very similar;
the protocone is symmetrical and less high than in M1 and the lingual cingulum is
larger and more expanded. The only evidence of Mis a trace of the alveolus indicat-
ing a small, transverse two rooted tooth.

Mandibular teeth referred to the species are first and second molars. M, is a robust
tooth, the trigonid is about twice as long as the talonid; paraconid and protoconid
are sectorial, protoconid is much the largest cusp; the metaconid is small, adhering

MIOCENE CARNIVORA OF EAST AFRICA 291

to the protoconid with crest on level of the paraconid; the talonid is basined, length
and breadth about equal, hypoconid well developed and entoconid forms a low ridge.
M, is a stout rectangular tooth; the prominent protoconid is paired with a smaller
metaconid and there is no paraconid; posteriorly the hypoconid is keeled and
continues in line with the protoconid; the entoconid presents a curved ridge linking
the paraconid and hypoconid.

The other specimens do not call for any special comment. Most are M, and few
are unbroken.

REMARKS. Hecubides is known from three sites in the Kavirondo region of Kenya
and from Karamoja in Uganda. These, with Afrocyon from Libya, are the earliest
records of canids in Africa, the next being Canis and Vulpes in the Lower Pleistocene.
In comparing Hecubides with other canids, we may limit study to those genera
grouped by Simpson (1945) in the subfamilies Caninae, Amphicyonodontinae and
Amphicyoninae. The American subfamily Borophaginae is quite different and need
not be considered: the octocyoninae, with one living African genus and two possible
Pleistocene precursors, has very atypical molar characters: all simocyonines are
characterised by the absence of M? and very reduced M2.

Of the numerous American canid genera, none is as close to Hecubides as some
European Amp/icyon species. The following characters clearly differentiate the
American canids: many are either without M? (as Nothocyon, Cynodesmus, Mammo-
cyon and Pliocyon) or the tooth is very reduced as in Proamphicyon: in most genera
M? is considerably smaller than M! (e.g. Hesperocyon, Daphoenus and Campylocyno-
don): the development of the protocone on P‘is large with poor or oblique shearing
blade in Daphoenus and Daphoenodon, the protocone is small and the blade strongly
sectorial in Mesocyon and Mammocyon: the metaconid is a free and fully developed
cusp in the M! of Daphoenus and Parictis, and the talonid has high entoconid and
hypoconid cusps in Tomarctus and Leptocyon: a paraconid is present on M, in
Leptocyon and Tephrocyon. Omitting the oasis of synonyms, and other genera either
so different or so poorly known that they do not warrant discussion, only the
American species referred to Amp/icyon remain and these are discussed below
together with the old world species.

Among the European Tertiary canids, the closest affinities with Hecubides are to
be found among the Amphicyon group. Among the Hemicyon group of genera
(Hemicyon, Harpalaeocyon, Dinocyon, Plithocyon, Phoberocyon) there are fairly close
similarities in the structure of the upper and lower molars, but all are more specialised
for crushing; the teeth are more tuberculose, the upper molars wide and almost square
in some cases, the protocone of P4 large and medianly placed. The essential differ-
ences between Hecubides and the remaining genera can be briefly listed :Cynodictis
(with Plesiocyon and Pachycynodon) possesses viverrid-like characters—very reduced
M?and high tricusped trigonid on M ,: Cephalogale, Alopecodon and Pseudamphicyon
all lack M? and have reduced M?: Amphicynodon (synonyms Cynodon and Paracyno-
don) has tricusped trigonid on M, and a paraconid is present on My.

292 MIOCENE CARNIVORA OF EAST AFRICA

SS =
pS
Vir ATI \\\NS
\

Fies. 50-54. Hecubides eurydon gen. et sp. nov. (50) Maxilla with P3-M!, based on the
right and left sides of dentition; occlusal aspect. Holotype (M.19084), Napak. (51)
same, lateral aspect. (52) M; and Mg, based on M.19085, M.19099 and CMF.4027;
occlusal aspect. (53, 54) Mj, based on M.19085 and M.19099; medial and lateral aspects.
All x2.

MIOCENE CARNIVORA OF EAST AFRICA 293

Only two additional genera require examination to survey the Asiatic Tertiary
canids. Vishnucyon bears no resemblance whatever to Hecubides; its P4 is without
a protocone, the M! is deeply waisted and M? very reduced. Arctamphicyon, known
from M1!*+2, suggests ursid affinities in its narrow but transversely extended molars.

The type species of Amphicyon is A. major Blainville. This species is clearly
generically distinct from Hecubides, the most striking differences being in M2, which
on Amphicyon major is asymmetrical transversely, has a crenulated internal cingulum
and the paracone is much larger than the metacone: the molar teeth are subsquare
rather than sub-triangular and the internal cingulum is less extensive in both teeth
than in those of Hecubides. All four premolars are present though P tis vestigial and
there is a diastema between it and the canine, which reaches the proportions of a
sabre-tooth: the diastema behind the upper canine suggests further an elongate
lower canine. The asymmetry of the buccal border of M? and the striking difference
in size of paracone and metacone, are features which clearly mark off the Amphicyon
group from Hecubides.

About 70 species have been referred to the genus Amphicyon. Apart from a
profusion of synonyms it is clear that several genera are involved and some of the
species bear little resemblance to the type species. Only those which are clearly
nearer to the genus Hecubides than to the type species A. major will be discussed
below. None of the eight Asiatic species of Amphicyon come within this category.
Of the 18 American species attributed to Amphicyon, A. americanus more closely
resembles Hecubides than A. major. I have been able from a cast to confirm
Matthew’s remarks (1924: 106) that A. sinapius is closer to A. major than to A.
lemanensis and has no proximity to Hecubides. None of the other American species
comes within the scope of the discussion and only A. americanus is transferred to the
new genus Hecubides.

Among the European Amphicyon species, A. lemanensis stands out as quite distinct
from all others, and close to Hecubides euryodon. Both species are about the same
size; P4, M 1:2 are almost identical in each, M! of A. lemanensis has a crenulated
protocone and the postero-internal cingulum is much larger and more asymmetrical,
while the M? is proportionately broader transversely and the external border is
directed postero-internally. Both species are undoubtedly closely allied and the
European species is thus placed in the new genus. A. dehmi Crusafont, from the
Burdigalian of Vallés-Penedés, N.E. Spain appears to fall between Hecubides and
Amplicyon. The rather squarish molars, M! slightly asymmetrical, M? with pos-
periorly crenulated internal cingulum and a paracone which is slightly larger than
the metacone tend to suggest a closer proximity to Amphicyon sensu stricto.
Crusafont (1955) has justifiably placed the species in a new subgenus Jctzocyon of the
genus Amphicyon.

In conclusion therefore, the new genus Hecubides has four known species, the type
species H. euryodon and another new one from East Africa, H. macrodon. To these
are added H. americanus (Wortman) from Nebraska (age unknown), and H. lemanen-
sts (Pomel) from the Aquitanian of France and Germany. Hecubides appears to be

294 MIOCENE CARNIVORA OF EAST AFRICA

an earlier offshoot of the dogs than Amphicyon: the latter could be said to be more
specialised in having molars more nearly square than triangular, a more elaborate
internal cingulum on M? and a greater development of the paracone at the expense
of the metacone.

Hecubides macrodon sp. nov.
(Pl. 5, fig. 2; Text-fig. 55)

Diacnosis. Large sized Hecubides species; M! about 25 mm. transversely and
20 mm. longitudinally; internal cingulum proportionately smaller and external
cingulum thinner than in type species.

HorotyPe. M.19086. Left M1.
Locality. Site 31, Rusinga Island, Kavirondo Gulf, Kenya.

DeEscripTIon. Mis structurally similar to that of H. euryodon, but larger, with
rounded and less pronounced features. The paracone is slightly wider than the
metacone: the protocone forms a broad and shallow crescent and the internal
cingulum, best developed posteriorly, is proportionately smaller than in H.ewryodon:
the external cingulum is very thin and forms only a skin on the lower edges of the
paracone and metacone.

I\S

Fic. 55. Hecubides macrodon sp. nov. Left M!; occlusal aspect.
Holotype (M.19086), Rusinga Is. x1°5.

REMARKS. Few deductions can be made from an isolated tooth, but its difference
from H. euryodon in size and minor details of structure, seem sufficient to merit
specific distinction. The remarks on the type species regarding the relationships to
Amplhicyon apply also to this species.

A right P4 (CMF.4070) from Rusinga is also referred to H. macrodon,; the tooth is
very broken and only the outer edge of the paracone and metastyle survive.

MIOCENE CARNIVORA OF EAST AFRICA 295

TABLE 8

Measurements (in mm.) on the dentitions of Hecubzdes.

is pe Mt M2 M3 M, M2

Hecubides euryodon
P3_M? M.19084 (Holotype) a—p 103, GOH EAH) AUG) —- ARO BOF)
M, M.19085 (Paratype)
M, CMF.4027 trs 5°3 10°3 17°5 16°4 — 9°6 10°3
Hecubides euryodon a—p 23°5
Hunt. Mus. V.5830

trs org)
Hecubides macrodon a—p 20°5
M.19086
(Holotype) trs 24°2
Hecubides americanus a—p 15 27 20 17 8
(Wortman)
(Holotype, approx.) trs 8 17 27 22 12
Hecubides lemanensis a—p 17°4 14°5
(Pomel)
(B.M.N.H., no. 30879) trs 10°3 18°4
Hecubides lemanensis a—p 15'1 12°0
(Pomel)
M.7643 trs 19°5 WAP
Hecubides lemanensis a—p 20°
(Pomel)
(B.M.N.H., no. 26733) trs g'I
Amphicyon (Ictiocyon) a—p 16°6 15°6 II‘5 7°4 18:0
dehmi Crusafont
(Holotype) trs TACT 17°5 164 UH) 9°7
Amphicyon major de
Blainville a-p 32°3 PagfAk 22°4
(B.M.N.H., no. 29615)
(Cast of holotype) trs 19°2 35°0 Bey

Superfamily FELOIDEA Simpson
Family VIVERRIDAE Gray

Diacnosis. Skull elongate, low with long snout; auditory bulla composite with
ecto- and ento-tympanic parts, wholly or only partially ossified. Dental formula
$14.2: M1+2 large, tritubercular: P* with well developed protocone; parastyle and
metastyle usually present: M, long with tritubercular trigonid and basined talonid;
trigonid cusps usually high; oe esee P4/M ,, truly sectorial except in few specialized

genera. [After Pilgrim 1931].

296 MIOCENE CARNIVORA OF EAST AFRICA

REMARKS. On teeth alone it is impossible to separate with certainty the miacids
from the viverrids and the auditory region is essential for this purpose. This region
is missing from the specimens described below and hence their place in the Viverridae
must be regarded as provisional. The later miacids and early viverrids are so similar
that it is impossible to make a sharp division. Gregory & Hellman (1939) included
miacids within their family Viverridae though this practice has not been generally
accepted. The miacid subfamily Viverravinae is closest to the Viverridae, all its
members lacking M, as in viverrids. Simpson (1945) recognised seven subfamilies
in the Viverridae, of which only three, Stenoplesictinae, Viverrinae and Herpestinae
are known in the fossil record: the latter two subfamilies contain half the 42 recog-
nised genera in the family.

Subfamily HERPESTINAE Gill

DiaGnosis. External auditory meatus long. Carnassial teeth not strongly
trenchant: molars rather more sectorial than tubercular.

REMARKS. The Herpestinae are essentially less specialized in the carnassial
direction than the Viverrinae, though the trenchant character of the teeth is not so
reduced as in Paradoxurinae and Hemigalinae. It is on this basis that the fossils
described below are included in the Herpestinae, in leu of any knowledge of the
auditory region. No extinct genera are ascribed to the subfamily and only Herpestes
among the ten genera listed by Simpson (1945) has a fossil record, which in Europe
extends into Upper Oligocene. The lack of differentiation of distinct fossil genera
reflects difficulties of establishing diagnostic characters.

Genus KICHECHIA nov.

DiAGnosis. Herpestine with upper dental formula 3.1.4.2. Teeth not com-
pressed ; canine long and slender; parastyle present only on P4; upper molars without
conules and without hypocone; protocone crescentic and without anterior and

posterior wings.

TYPE SPECIES. Kichechia zamanae sp. nov.

REMARKS. Only the holotype and isolated teeth or partial dentitions are known
and they possess no characters which would preclude them from the Viverravinae.
The sum of the dental characters is diagnostic, though individually several of them
are to be found in other genera.

Kichechia zamanae gen. et sp. nov.
(Pl. 5, fig. 3; Text-figs. 56-60)
Diacnosis. The only known species, diagnosis as for genus.
The name is derived from the Swahili word kichechi, a mongoose, and zamani
meaning ancient.

HoiotyPe. M.19077a, b. Facial region of skull and anterior part of braincase
with complete upper dentition on right side except P?.

LOCALITY.

PARATYPES.

M.19078 Right mandible with Canine root; P, 4; root of M,.
Rusinga Island.
M.19079 Right M,. Rusinga Island, Kavirondo Gulf, Kenya.
M.19080 Right mandible with P,; M, 4. Songhor, Kenya.

MIOCENE CARNIVORA OF EAST AFRICA

Site R 1, Rusinga Island, Kavirondo Gulf, Kenya.

ADDITIONAL MATERIAL.

From Rusinga Island, Kavirondo Gulf, Kenya.

CMF.4003
CMF.4004
CMF.4006
CMF.4008
CMF .4009
CMF.4010
CMF. 4011

CMF.4012
CMF .4014
CMF.4015
CMF.4016

CMF.4017
CMF.4029
CMF.4030
CMF.4031
CMF .4032
CMF.4033
CMF .4034
CMF.4035
CMF.4036
CMF.4037
CMF.4071
CMF.4072
CMF.4074
CMF.4075
CMF.4076
CMF.4077
CMF.4078

CMF.4005

From Moruorot, Northern Frontier District, Kenya.
CMF.4013 Right mandibular fragment with P, root, Pg 4, My.

Right M1.

Left M1land alveolus of P4. Site 12.

297

Site 2,

Left mandible with C root, P, alveolus, Py 4, My. Site 1.

Left mandibular fragment with P,, M,.
Left mandibular fragment with C, P, roots, Pg 4.
Left mandibular fragment with M,. Site 1.

Right mandibular fragment with P,, M,; roots of P, ,and Mg.

Site I.

Right mandibular fragment with P, ,, M,; roots of P, and C.

Right M,.

Right mandibular fragment with P, ,, M,; roots of Py and Mg.
Right mandibular fragment with P,, M,; roots of P, and Mg.

Site Ia.

Right mandibular fragment with P,; roots of M, 5.

Right mandibular fragment with P,, M,; roots of Mg. Site 1.

Left mandibular fragment with M,, broken P,.
Left mandibular fragment with P, and broken M,.
Left mandibular fragment with M,; root of Mg.
Left mandibular fragment with P,_,.

Beit ite Site 6:

Right M,.
Right P,.

Left P4. Site r.
Right maxillary fragment with P4, M! 2,

Left P4.

Left upper canine.

Left mandibular fragment with P,, M,.
Left mandibular fragment with Pg.
Left M, in mandibular fragment.

Left P,_, in mandibular fragment.

From Mfwanganu Island, Kavirondo Gulf, Kenya.

Right M1.

298 MIOCENE CARNIVORA OF EAST AFRICA

From Songhor, Kenya.
CMF.4073 Anterior facial region of skull with nasals, maxillae, frontals,
palatines; no teeth.

From Napak, Karamoja, Uganda.
UMP64.35 Left mandibular fragment with C and roots of P, 4. Napak V.
UMP64.34 Right M,. Napak IV.

DescriPTION. In the holotype the facial region of the skull is complete but is
broken off about the fronto-parietal junction and the whole of the posterior is
missing. The skull is fractured and partly displaced, but may have had size and
proportions similar to a living mongoose.

The face is long, low and narrow. The premaxilla has a long, tapering ascending
ramus which reaches back to the line of P!. The maxilla is almost wholly vertical
on its outer face and posteriorly carries the stout base of the zygomatic arch: the
infra-orbital foramen is smaller than the canine alveolus and lies almost immediately
above P3. The frontal bones are flattened dorsally. The extremities of the post-
orbital processes are broken on each side, but from their roots it can be judged that
they were well developed: since the zygoma is broken off near its anterior root, it is
not possible to estimate how fully the orbit was enclosed posteriorly. From the
postorbital process a ridge sweeps posteriorly toward the mid-line; these two ridges
meet and continue medianly backward, but do not form a true sagittal ridge; the
ridge indicates the upper limits of the origin of the temporal muscles and their
meeting medianly suggests powerful musculature to the mandible. The skull is very
constricted immediately behind the postorbital processes, narrowing to 9 mm. after
which it expands rapidly to 20 mm. width; posteriorly to this it is missing. The
anterior palatine foramen is about the size of the alveolus of I3, lying near the
median plane between I? and C in the narrow pre-maxillary region. The posterior
palatine foramina are smaller and lie opposite the posterior end of P,. The palatine
bone is almost the same length as the palatine portion of the maxilla, extending
backward 18 mm. from the anterior edge of P4: the pterygoid process is broken.

The horizontal ramus of the mandible is preserved in one of the paratypes
(M.19078): the bone is slender in transverse section and relatively shallow dorso-
ventrally compared with its length. The teeth are closely packed; a large mental
foramen occurs below P, and there are several smaller ones posteriorly.

DENTITION. The dental formula is 2++4:5. The holotype has all three incisors

and the canine on each side, together with P2, 3+4, M1*? on the right side. The three
incisors lie transversely on a slight curve, all close together, I? is slightly larger than
I1, and I is much larger than I?: I! and I? are spatulate. I?is conical with a groove ~
cutting postero-buccally across it and worn by friction with a ridge on the antero-
lingual border of the lower canine. A diastema 3.1 mm. long separates I? from C.
The canine is long, slender, gently tapering and slightly curved: in transverse section
it is ovoid, more flattened lingually than buccally: anteriorly the tooth is rounded
and posteriorly keeled: there is a slight ridge on the antero-lingual margin.

P! follows immediately behind C without any gap: the tooth is absent on both

MIOCENE CARNIVORA OF EAST AFRICA 299

Fias. 56,57. Kichechia zamanae gen. etspnov. Facial region, left and right sides united
in reconstruction. (56) Occlusal aspect. (57) Lateral aspect. Holotype (M.19077),
Rusinga Is. x2.

sides and only the small single alveolus remains. P?is a two-rooted tooth with single
cusp, whose height is equal to its antero-posterior width at the level of the continuous
basal cingulum. P? is slightly larger than P?; cusp height is again equal to antero-
posterior width at the base of the crown; the cingulum is continuous and most
prominent posteriorly. P* is relatively broad and stout with the carnassial shear
oblique: the large prominent paracone continues anteriorly into a small parastyle:
the protocone is a low cusp, well developed; the metacone short and trenchant,
intermediate in height between paracone and protocone: a cingulum is present
buccally and posteriorly. M! is transversely broad; paracone and metacone are

300 MIOCENE CARNIVORAOF EAST AFRICA

equally developed; parastyle absent, but buccal cingulum present; protocone is
symmetrical, crescentic, and bounded internally by a cingulum. M?is very similar
to M! but smaller; cingulum less well developed. The continuity of bone behind M2
testifies to the complete absence of M3.

In the mandibular dentition no incisors are known. Only the root of the canine is
preserved and this extends posteriorly under P,,,. In section the canine is roughly
ovoid at the base and smaller than the upper canine. P, is unknown, but the single
small alveolus indicates an almost vestigial single cusped tooth. On P, the cusp is
asymmetrical, more steeply inclined and smaller on the anterior half; a cingulum is
present posteriorly and there is the trace of one anteriorly. P.,is an enlarged version
of P,; its cusp height is approximately equal to its antero-posterior length; the
posterior cingulum is well marked but the anterior one is small; a minute accessory
cusp 1s sometimes present on the posterior keel of the main cusp. P, is larger than

Iics. 58-60. Kichechia zamanae gen. et sp. nov. Mandibular dentition, P,-M,; composite
reconstruction based on M.19078, M.19079 and M.1g080. (58) Occlusal aspect. (59)
Lateral aspect. (60) Medial aspect. x3.

MIOCENE CARNIVORA OF EAST AFRICA 301

P.; the main cusp rises to about the same level as that of P, and is steeper buccally
than lingually; a small cingulum is present on the antero-lingual extremity. The
posterior slope of the main cusp carries a prominent accessory cusp on the buccal
side while postero-lingually is developed a low cingulum.

On M, the protoconid is the highest of the three cusps on the trigonid, with the
paraconid more robust than and very slightly higher than the metaconid: the buccal
border of the protoconid and paraconid is trenchant and the two cusps are separated
by a deep notch: the talonid is about the same length as the trigonid; the prominent
hypoconid is separated from the trigonid by a deep cleft and the lingual border of
the talonid is fringed by a slightly crenulated cingulum. M, is present only on one
specimen (M.1g080) and on this is damaged: it is a small two-rooted tooth with
apparent low protoconid and metaconid; the talonid is slightly larger than the rest
of the tooth, carrying a hypoconid buccally which continues lingually as a low
cingulum.

REMARKS. Among the living herpestines, the dentition of Bdeogale is closest to
Kichechia, both animals being about the same size. In Bdeogale, 1? is larger than in
Kichechia, while the upper canine of the fossil genus is slightly larger and curved
posteriorly unlike the straight canine of Bdeogale. P? in the living genus is large,
with an internal cusp not found in Kichechia. P4is very similar in both genera,the
metastyle being slightly larger and the protocone more anteriorly placed in Kichechia.
The first upper molars are essentially similar, the fossil form having a slightly less
prominent external cingulum and more prominent internal one. The proportion of
M1/M? is alike in the two genera.

In the mandibular dentition the premolars are similar, but the molars display
differences. M, trigonid in Bdeogale is unusual, the metaconid being connate with
the paraconid, and the protoconid and paraconid being separated by a trough, at the
base of which arises an incipient cusp (paraconulid); the talonid has a prominent
hypoconid: M, is proportionately much larger than in Kzchechia with well developed
trigonid and talonid. These differences in the lower dentition are striking, but two
points of importance are first, the lower teeth referred to Kichechia are not asso-
ciated with maxillary parts in the same specimen and hence their relationship is only
an inferred one; secondly the mandibular molars of Bdeogale are highly exceptional,
differing from other genera of herpestines.

The essential character of the dentition of Kichechia—the formula, tooth pro-
portions, cusp development and degree of sectorial development—all suggest close
affinity with Herpestinae. The Viverrinae are more specialized in the sectorial
direction than the Herpestinae, but on dental characters alone Kichechia could
represent the common stock from which both lines evolved. Comparison with the
Miacidae, especially the Viverravinae, is valid in terms of dental formula and tooth
structure, but differs in detail. Kzchechia lacks the strong parastyle on M! and the
high M, trigonid with weak talonid so characteristic of viverravines.

Kichechia has no close affinity with the Stenoplesictinae, the only other Tertiary
viverrids. Kichechia is the earliest known example of a viverrid in Africa, the next
record being in the Pleistocene.

302 MIOCENE CARNIVORA OF EAST AFRICA

TABLE 9

Dental measurements (in mm.) of Kichechia zamanae

C ips Ip pe Pe M1 M2
M.19077b ant-post 4°1 — 4°0 4°4 6:6 4°4 3°2
lat 2°8 _— 2°2 3°7 6:0 6°9 5°4
12a IP Vea M, M,
CMF.4006 ant-post 3°8 4°5 5°60 65
lat 2°1 2°7 3°3 3°8
M.19078 ant-post 3°60 4°4 5°8
lat 2 2°9 3°4
M.19079 ant-post 6°7
lat 3°7
M.19080 ant-post 4°0
lat 2°8

Family FELIDAE Gray

Diacnosis. ‘‘Aeluroidea, primitively with long skull, becoming progressively
shorter, especially the face; rather inflated braincase; alisphenoid canal only present
in primitive forms; entotympanic portion of auditory bulla very large, separated by
a high septum (occasionally doubtfully so) from the laterally placed, smaller ecto-
tympanic; external auditory meatus short; paroccipital process separated from the
mastoid process, stretched out against the hinder part of the bulla; dental formula
g--3-4-7: canines strongly developed; M, with two converging blades developed
from paraconid and protoconid; primitive forms with strong metaconid, progressively
becoming fused with protoconid, talonid only present in primitive forms, trenchant,
progressively disappearing. M+ and M, always small; premolar series progressively
reduced; humerus usually with entepicondylar foramen; extremities relatively long
and slender, digitigrade; manus 5-dactyl; pes generally 4-dactyl; claws retractile,
except in Acinonyx and allied genera; os penis rudimentary.” (Pilgrim 1931).

REMARKS. The division of the family into four subfamilies as given in Simpson
(1945) is adopted here.

Subfamily NIMRAVINAE Trouessart

Diacnosis. Felids with large incisors; upper canine enlarged and lower canine
normal or slightly reduced; carnassial teeth deeply notched; P* large, P* with well
developed protocone, strong paracone and parastyle present; anterior premolars
absent or vestigial.

REMARKS. The large upper canines and incisors distinguish the subfamily less
from the Felinae than the deep notches on the carnassial teeth distinguish it from
the Machairodontinae. Scott & Jepsen (1936) erected the subfamily to accommodate
Archaelurus and Nimravus and specifically excluding Pseudaelurus and Metailurus.
Teilhard de Chardin (1945) suggested the erection of the subfamily Pseudaelurinae
to accommodate Pseudaelurus and Metailurus. Simpson (1945) placed all the above

MIOCENE CARNIVORA OF EAST AFRICA 303

genera in the Nimravinae. The latter grouping is followed here giving a total of ten
genera; Adlurictis and Dinailurictis from the European Eocene and Oligocene:
Dinictis, Nimravus, Dinaelurus, Archaelurus and Pogonodon from the Oligocene and
Lower Miocene of North America; Pseudaelurus from the Miocene of Europe and
North America; Metailurus from the Upper Miocene of Europe and Asia. Kitts
(1958) erected the genus Nimravides to accommodate the North American Pliocene
species Pseudaelurus thinobates. The subfamily shows features in advance of the
Proailurinae and probably includes ancestral stocks of both felines and machairo-
dontines.

Genus METAILURUS Zdansky 1924

Diacnosis. Nimravine with P1+? absent, P? large and P* with strong paracone
and well developed parastyle: P, if present very reduced.

TYPE SPECIES. Metailurus major Zdansky.

In addition to the type species, Zdansky (1924) described another species, M.
minor from the same Pontian beds of China. Colbert (1939) described M. mongoliensis
from the Vindobonian of Mongolia, and Thenius (1951) transferred Felis letodon
Weithofer to the genus as M. parvulus. Andrews (1914) described a mandible from
Karungu, Kenya as Pseudoaelurus africanus and below this is transferred to the
genus Metailurus.

Remarks. Matthew (1929: 496) wrote “Metailurus does not seem to me to be
separable generically from Pseudaelurus, although it represents an intermediate
stage between that genus (typically) and Felis. Nor do I find any reason for removing
the American species from Pseudaelurus, with the typical species of which they agree
more nearly than they do with the types of Metailurus.”’

Stock (1934) summarized the characters of Metailurus as follows:—
““Metailurus Lower Pliocene. Dentition $4:5:+ P*4 with well developed para-
style. M, with heel considerably reduced. Diametral index of superior canine,
63.8 (M. major), 66.3 (M. minor). Anterior end of mandibular ramus without
flange or angulation. Condylar and carotid foramina closely connected with
foramen lacerum posterius. No alisphenoid canal. Tympanic bulla completely

ossified.”’

Taken together with his list of characters for Pseudaelurus, the generic distinction is
perfectly clear. Metailurus is at present better known than Pseudaelurus; though
represented by fewer species, they are much more complete than anything known of
Pseudaelurus. Pseudaelurus may be distinguished from Metailurus by having 3-4
premolars and on P* the parastyle is weak. The progressive trends from Pseudaelurus
through Metailurus to Felis are the reduction of the anterior premolars and the
reduction of the protocone with corresponding increase in the size of the parastyle on
P4. The size changes in the upper canine do not appear to follow a definable trend.
Metailurus represents an intermediate stage morphologically between Pseudaelurus

304 MIOCENE CARNIVORA.OF EAST AFRICA

and Felis and it seems preferable to retain this generic distinction; Pseudaelurus for
the European and American species, Metailurus for the Asiatic species. This holds
true for all but two species, “F’elzs’’ lecodon and Pseudaelurus africanus, the latter
being discussed below.

A fragment of a right mandibular ramus from Pikermi was described by Weithofer
(1888) as ‘Felis’ letodon: this has been shown by Thenius (1951) to be conspecific
with another mandible from Pikermi described by Hensel (1862) as Machairodus
parvulus. On the strength of a newly described maxillary dentition from Pikermi,
Thenius regarded all Pikermi specimens as generically comparable with Metailurus
minor from the Chinese Pontian and in consequence has renamed “‘Felis’’ letodon as
Metailurus parvulus (Hensel). Teilhard de Chardin (1945: 18-23) referred to
“Metailurus tunggurensis Colbert 1939, p. 78, fig. 18’’: this is a mistake for Metailurus
mongoliensis.

Metailurus africanus (Andrews)
(Pl. 5, fig. 4; Text-figs. 61, 62)

1914 Pseudaelurus africanus Andrews: 178-179, pl. 29, figs. 1a, b.

Diacnosis. Dental formula #27; a Metailurus intermediate in size between

M. major and M. minor. The anterior process of the nasal bone elongate: upper
canine somewhat more ovate than in M. major: P* paracone and metacone equal
length; large maxillary and mandibular canine-premolar diastema; vestigial P,
present.

HoLotyPe. M.10634. Left mandibular ramus with Ig, C, P3;4, from Bed 31 at
West Kachuku, Karungu, Victoria Nyanza, Kenya.

ADDITIONAL MATERIAL. M.19076. Facial region of skull, the maxillae with all
dental alveoli and P#+4 present, described and figured below. From Site 18, Rusinga
Island, Kavirondo Gulf, Kenya.

CMF.4001 Isolated P, from Songhor.

DescriPTIon. Most of the anterior of the skull is preserved though much crushed.
The premaxilla has a long ascending ramus which probably almost reached the
frontal; centrally the anterior palatine foramen is about the same size as the alveolus
of 1*. The convex surface of the maxilla is evidence of the deep roots for the canine
tusks. The infra-orbital foramen is drop-shaped, its height being about half the
length of the canine alveolus: the lower border of the foramen is situated about
1.5 cms. above the base of the main cusp of P®. The nasal bone is long and broad,
with a prominent anterior descending ramus overlapping the premaxilla. The frontal
bones, though incomplete, suggest a narrow interorbital region: the post-orbital
process was short and from its posterior border arises the ridge demarcating the

MIOCENE CARNIVORA OF EAST AFRICA 305

anterior limit of the temporal muscle; this ridge ascends rapidly and meets the sagit-
tal line about 1.5 cms. behind the postorbital process. The jugal is very robust;
posteriorly it is broken and cannot be traced beyond the orbit.

P3+4 are preserved on both sides but only the alveoli of the other teeth remain.
The alveolus of I? is slightly larger than that of I! and much compressed laterally.
The alveolus of I*is very much larger than that of I?, more or less circular, and on the
right side contains the tooth root. The three incisor alveoli lie close together in an
arc and are separated by a short diastema from the large oval canine alveolus. The
canine alveolus measures 16.2 mm. antero-posteriorly and the maximum transverse
width is 9.0 mm. The canine js separated from the premolar series by a diastema
almost as long as the canine alveolus. There is no trace on either side of any pre-
molar anterior to the bi-rooted P?. The prominent central cusp of P* has an anterior
keel terminating in a small anterior cusp: the posterior half of the central cusp is
broken on both teeth: the posterior cusp is larger than the anterior one and a
cingulum terminates the tooth posteriorly. In P* the paracone is slightly higher
than the metacone and equal to it in length: internally the two cusps are sectorial
and externally are separated by a deep trough: the metacone terminates in a ridge,
the paracone in a point: the parastyle is in line with the metacone and paracone and
is larger than the protocone. The alveolus of M! indicates a small bi-rooted tooth
lying transversely close behind P4.

RemArkKS. From the table of measurements on the dentition, WM. africanus can be
seen to be comparable in size with M. mongoliensis and M. parvulus, and inter-
mediate between M. major and M. minor. From the alveolus, the upper canine of
M. africanus appears to have been intermediate in size between M. major and M.
minor, though more ovoid than either of these two species and in this character
similar to M. parvulus. P?+4 are proportionately more similar to those of M. major
than to other species. The equality of paracone and metacone length on P# allies the
species to the Chinese forms and differentiates it from M. parvulus. The incisor-
canine diastema is of similar size in M. africanus and M. major and much larger in
the smaller species M. minor. The canine-premolar diastema in M. africanus is much
larger than that of any other species. The anterior process of the nasal is longer in
African species than in either of the two Chinese species.

The holotype mandible described by Andrews fits the above skull perfectly; the
size and spacing of the teeth correspond precisely. P, in the holotype must have
been minute judging from the pinhole alveolus; thus the effective diastema extended
from canine to P, and the outer concavity of the mandible in this region gave room
for the long upper canine when the jaw was closed, a feature better developed in
M. major than in M. minor.

The additional tooth referred to the species (CMF.4001) is a P,. It measures
5-6 mm. laterally and 11.5 mm. antero-posteriorly. The tooth is indistinguishable in
character from P, on the holotype, but is slightly smaller; their ratios of length to
breadth are identical.

MIOCENE CARNIVORA OF EAST AFRICA

306

ee a ’
aM 1 ) Y 7 G3

y f
'

Facial region, distortion corrected.

(M.19076), Rusinga Is. x1.

Metailurus africanus (Andrews)
(62) Lateral aspect.

Fics. 61, 62.
(61) Occlusal aspect.

MIOCENE CARNIVORA OF EAST AFRICA 307

The stratigraphic distribution of the species of Pseudaelurus and Metailurus is as

follows:

Pseudaelurus quadridentatus Gervais

Metailurus

(type species)
lorteti Gaillard
transitorius Depéret
tournauensis (Hoernes)
marint Villalta & Crusafont
aluroides MacDonald
pedionomus MacDonald

intrepidus Leidy

marsht Thorpe

martint (Hibbard)

kansensis (Hibbard)

major Zdansky
(type species)

minor Zdansky
parvulus (Hensel)
mongoliensis Colbert

africanus (Andrews)

Vindobonian, Europe

Vindobonian, Europe
Vindobonian, Europe
Vindobonian, Europe
Vindobonian, Europe
Barstovian, N. America
Clarendonian, N. America

Barstovian-Clarendonian,
N. America

Clarendonian, N. America

Hemphillian,
N. America

Pontian, Asia

Pontian, Asia
Pontian, Europe
Sarmatian, Asia

““Miocene’’, Africa

The European Pseudaelurus species are all Vindobonian in age and the North
American species higher, ranging from the Barstovian to the Hemphillian. The
Mongolian species of Metailurus is Sarmatian (Tung Gur formation), the Chinese
and Pikermi species are all Pontian. Pseudaelurus is more primitive, occurs earlier
in the stratigraphic record and appears to persist longer than Metailurus. The species
and distribution of both genera are, however, not sufficiently abundant to enable
any firm stratigraphic conclusions to be drawn for the African occurrence, save to
suggest that Middle to Late Miocene is likely.

308 MIOCENE CARNIVORA OF EAST AFRICA

TABLE I0

Measurements (in mm.) on dentitions of Metailurus
*—alveolus measured

Metailurus Metailurus Metailurus Metailurus Metailurus
africanus major minor mongoliensis parvulus
(Andrews) Zdansky No. 3+4 AM.26599 ex. Thenius
M.19076 Pontian: Zdansky Colbert Pontian:
and M.10634 China Pontian: Miocene: Pikermi
Miocene: China Mongolia
Kenya
i lat — 3°0 2°8 —
Ev aa AW 3°6 a
i12 lat 3°2* 4:0 3°5 —
a—p 5:0* 5°4 4°3 =
18 lat 4°8* 6°7 4°8 —
a—p Gp Be 8-2 5:2 —
Gc lat 9:0* II°5 7°8 6°9*
a—p 16°2* 18°7 12°3 12°9*
P3 lat 5°7 8-9 6°6 6°7
a—p 13°0 20°2 13°7 13°5
ID lat 10°3 14°0 10°6 9°5
a—p 21°0 31°2 24°0 21°4
Mt lat I0'0 II°9 10'0 9°3
a—p yo) SS) 47 Art
I, lat — BOG] 2 23 —
a-p ait 33 2°7 2°0 =
I, lat — 3°8 2°9 3°0 —
a—p aa 4°2 3°0 2°7 =
I, lat 2°8 5°6 4° Be =
a-p ays) DIS 3°9 3°3 a
€ lat 55 9:0 65 13 6°6
a—p Io°l 12°7 8:8 II'5 g'I
P3 lat 4°6 8-4 53 5°7 =
a—p Iorl 15°5 9°9 12°0 —
Py, lat 6:8 953 6°5 6:8 6°5
a—p 13°9 21°O 14°5 I5'0 15'0
M, lat — Iovl 72 7°2 7°0
a—p -— 23°2 18° W763 17°8
Ratios (lateral/anteroposterior)
C o>. “61 "65 = oh
Bs "44 "44 “48 = "50
Ee "49 "45 "44 = "44
M1 “35m "46 "47 aa "44
C 54 ‘71 "74 65 72
Ps 45 "54 "53 47 a
Py 49 "44 45 45 43
Mi = "43 "40 "42 "39
Diastemae
Le-€ 4°4 4°3 62 o =
C-Ps 13°0 5°8 3°4 = 37

C_-P, 20°8 18°5 84 5°5 Gpo72

MIOCENE CARNIVORA OF EAST AFRICA 309
Til. CONCLUSIONS AND THE AGE OF THE FAUNA

The carnivores do not reveal much about the environment, being predators mainly
dependent on the herbivores in the fauna. They range from very small species about
the size of a stoat to the large hyaena-like Pterodon. The picture of forests on the
volcanic slopes, swamp with gallery type vegetation and savannah with flash floods
is well described by Chesters (1957) and by Bishop (1963).

The carnivores described in this paper are recorded from nine localities. Two of
these, Rusinga and Napak, are subdivided into a number of sites and these are
quoted where known; unfortunately many of the best finds were made on Rusinga
before site designation was initiated. Rusinga Island, Mfwanganu Island and
Karungu in western Kavirondo are associated with the Rangwa volcanic centre.
Ombo is a high level site in eastern Kavirondo. Songhor and Koru are in Nyanza,
east of the Kavirondo Gulf and associated with the Tinderet volcanic centre. Moruorot
is in the Northern Frontier District of Kenya and Napak in Karamoja, Uganda.
Kaboor is in Turkana, Northern Kenya.

Age analysis can be based on three lines of evidence; the relationships of the
carnivores to other carnivore faunas, the deductions obtained for other faunal
elements and radiometric dating of the fossiliferous tuffs.

TABLE II
Distribution of the carnivores by sites

Elizabethfeldern

Fayuim

+ Napak
Moruorot

+ Mfwanganu

+ Rusinga
Karungu
Ombo
Maboko
Songhor
Kaboor

Kelba quadeemae
Teratodon spekei
Teratodon enigmae
Anasinopa leakeyi
Metasinopa napaki +

Dissopsalis pyroclasticus ar
Metapterodon kaiseri

Metapterodon zadoki

Pierodon africanus af ae
Ptevodon nyanzae

Leakitherium hiwegi

Hyaenodon andrewsi + ar
Hyaenodon matthewti

Hyaenodon pilgrimi

Hecubides euryodon +
Hecubides macyodon

Kichechia zamanae + al.
Metailurus africanus

a
a
a
a
Sinbaln
+ Koru

++4++++4+4++4+4+44
++ +444

310 MIOCENE CARNIVORA OF EAST AFRICA

The carnivore evidence for stratigraphical dating can be summarized for individual
genera. Kelba, if an arctocyonid, has its closest relationships among the Palaeocene
and Eocene arctocyonids of North America, which have two late survivors in the
Lower Oligocene of Mongolia. Tevatodon finds closest comparison with Quercytherium
from the Phosphorites du Quercy (Upper Eocene to Middle Oligocene) of France.
Anasinopa is comparable with Sinopa and Tritemnodon from the Middle Eocene of
North America and Europe, and is more primitive than Metasinopa from the
Fluviomarine Series (Sannoisian, Lower Oligocene) of the Fayim, Egypt, the latter
genus being also known from Napak I. The Dissopsalis species from Kaboor is
closely comparable with D. carnifex from the Chinji Stage (probably Middle Miocene)
of India. Metapterodon from Karungu and Rusinga is also known from Southwest
Africa and Stromer (1926) on the basis of this and other faunal elements suggested
a similar age for both deposits. Pterodon africanus is known from the Kavirondo
sites and from the Sannoisian of the Fayim. The genus Hyaenodon ranges in
Europe from Upper Eocene to Upper Oligocene, with more restricted ranges in
Asia and North America; one species, H. andrewsi is common to the Sannoisian of
the Fayim and to East Africa. Hecubides may be regarded as a primitive
‘Amphicyow’ ; this form genus is recorded from the Middle Oligocene to Late Miocene
(Stampian-Pontian). The non-African species of Hecubides are H. lemanensis from
the Aquitanian of France and H. americanus from Nebraska (horizon unknown).
Kichechia is a herpestine, the subfamily being recorded from Upper Oligocene times
in Europe. Metailurus africanus is closely comparable with two Pontian species
from China. The evidence is thus equivocal, the creodonts suggesting Oligocene
and the fissipeds Miocene dating; since they are of holarctic origin the creodonts
might be expected to survive later in Africa and this is borne out by the novel
character of the fauna. If a single age is required by other evidence, then Lower
Miocene is most likely.

Proboscideans and anthracotheres are useful mammalian taxa in comparative age
analyses. Andrews (1914) designated a Lower Miocene (Burdigalian) age to the
Karungu deposits on the basis of the close affinity of Deinotheriwm hobleyi with
D. cuviert from France. The association of a small species of Deinotherium with
Gomphotherium angustidens in the Kavirondo is also well known outside Africa from
the Burdigalian deposits of Sables de l’Orleanais, France; El Papiol, Spain; Koty-
haza, Hungary and Bugti Hills, Baluchistan. G. angustidens occurs at all these sites
and the Deinotherium species are virtually indistinguishable. Most of the sites also
contain anthracotheres comparable with East African species, but carnivores are
poorly represented, usually by Amp/icyon fragments. Burdigalian faunas have been
identified in other parts of Africa. In Southwest Africa Stromer (1926) found no
proboscideans or anthracotheres, but the carnivore, hyracoid and lagomorph
elements support his argument for comparison with Kavirondo sites. The Moghara
site, west of Cairo, yielded G. angustidens but no Deinotheriwm and only one carnivore
(Hyaenaelurus) (Fourtau 1920). At Gebel Zeltan in Central Libya Deinotherium
hobleyt occurs in association with Gomphotherium angustidens, anthracotheres,
hyaenodont, felid and canid carnivores (Savage 1965). Recently the two probos-

MIOCENE CARNIVORA OF EAST AFRICA 311

cideans have been found at new sites in Algeria and Tunisia. All this evidence
strengthens the case for a late Burdigalian age for the East African faunas, at least
in part.

PALAEOCENE
EOCENE
OLIGOCENE
MIOCENE
PLIOCENE

Arctocyonidae
(for Ivelba)

Quercytherium
(for Tevatodon)

Sinopa
(for Anasinopa)

Metasinopa
Dissopsalis

Ptevodon

Hyaenodon
Amphicyon
(for Hecubides)

Herpestinae
(for Kichechia)

Metailurus

Pseudaelurus

TABLE. 12. Stratigraphic range of genera or nearest taxon where genera nova. Broken line
where record doubtful. @ Stratum with closely comparable species. 4 Stratum
with identical species.

Both Chesters (1957) and Verdcourt (1963) emphasised the uniformity and
modernity of the flora and mollusca throughout the succession, supporting the
concept of a single biotic assemblage. This evidence, while not directly useful in
dating, does not necessarily conflict with the Burdigalian estimate.

312 MIOCENE CARNIVORA OF EAST AFRICA

The fauna of Maboko (=Kiboko) Island in the Kavirondo Gulf has been stated
to be of two ages; Hopwood (in Shackleton 1951) argued for Burdigalian and
Helvetian ages on the basis of the proboscideans; Leakey (72 Whitworth 1958)
suggested Vindobonian or Pontian for the younger elements. Recent discoveries by
Leakey (1961) at Fort Ternan, a site associated with the Tinderet volcanic centre
as are Songhor and Koru, suggest the fauna is of Pontian age.

Radiometric dating of rock samples using K-A,4, is not yet complete. Preliminary
results for Napak I give 19 million years (Bishop 1964) ; for the basal (Kiahera) series
on Rusinga Island 15.3 and for Fort Ternan 14 million years (Evernden et al 1964).
The Napak figure would be consistent with a late Burdigalian age. The Rusinga
figure seems too young, but the sample gave ages ranging from 15.3 to 167 million
years and may not have been from the Kishara Series.

My current assessment is that more than one fauna is represented in the Kenya-
Uganda Tertiary sites; that one of these is Burdigalian in age with numerous sites
in east and west Kavirondo and in Karamoja. A younger fauna is present at Fort
Ternan; there is a hint of a post-Burdigalian fauna at Maboko and Kaboor, and
possibly at Rusinga, Songhor and Karungu, mainly on basis of Metailurus and
Dissopsalis. For the younger fauna a Vindobonian (Middle Miocene) and or Pontian
(Upper Miocene) age is probable.

IV. REFERENCES

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Soc. Lond., 1617: 91-94.
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MIOCENE CARNIVORA OF EAST AFRICA 313

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314 MIOCENE CARNIVORA-OF EAST AFRICA

HURZELER, J. 1944. Zur Revision der europaischen Hemicyoniden. Verh. naturf. Ges. Basel,
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MIOCENE CARNIVORA OF EAST AFRICA 315

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—— 1932. The Fossil Carnivora of India. Paleaont. indica, Calcutta, 18 : 1-232, pls. I-10.

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1934. Skull and Dentition of the American Miocene cat, Pseudaelurus. Bull. Geol. Soc.
Ameyr., Rochester, N.Y., 45 : 1051-1058, pls. 1, 2.

STOVALL, J. W. 1948. Chadron vertebrate fossils from below the Rim Rock of Presidio County,
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STROMER, E. 1926. Reste land- und siisswasser-bewohnender Wirbeltiere aus den Diamanten-
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WEITHOFER, A. K. 1888. Beitrage zur Kenntniss der Fauna von Pikermi bei Athen. Beitr.
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316 MIOCENE CARNIVORA OF EAST AFRICA

WuitwortH, T. 1954. The Miocene Hyracoids of East Africa. Fossil Mammais of Africa,
7: 58 pp., 7 pls. British Museum (Natural History), London.

1958. Miocene Ruminants of East Africa. Fossil Mammals of Africa, 15 : 50 pp., 18 figs.
British Museum (Natural History), London.

1961. The Geology of Mfwanganu Island, Western Kenya. Overseas Geol. Min. Resources,
8 : 150-190, pl. I.

WortMan, J. L. t901. A New American species of Amphicyon. Amer. J. Sci., New Haven,
11 : 200-204, 2 figs.

Youne, C. C. 1937. An Early Tertiary vertebrate fauna from Yuanchu. Bull. Geol. Soc. China,
Peking, 17 : 413-438, 16 figs.

ZDANSKy, O. 1924. Jungtertiare Carnivoren Chinas. Palaeont. sinica, Peking (C) 2, 1 : 1-155,
pls. 1-23.

IBID RAND, a

X12 approx
Fic. 1. Kelba quadeemae gen. et sp. nov. Right M2; occlusal aspect.
Holotype (M.19087), Rusinga Island.
Fic. 2. Tevatodon spekei gen. et sp. nov. Left maxilla with P4-M?;
occlusal aspect. Holotype (M.14307), Koru.
Fic. 3. Tevatodon spekei gen. et sp.nov. Maxillae with C, P?;
occlusal aspect. (M.14310), Koru.
Fic. 4. Tevatodon enigmae sp. nov. Facial region; occlusal aspect.
Holotype (M.19088a), Songhor.
Fic. 5. Tevatodon enigmae sp.nov. Left mandible; occlusal aspect.
(M.19089), Songhor.
Fic. 6. Anasinopa leakeyi gen. et sp. nov. Left maxilla with P4 and M};
occlusal aspect. Holotype (M.19081a), Rusinga Island.
Fic. 7. Anasinopa leakeyi gen. et sp. nov. Right maxilla with M! 2;
occlusal aspect. Holotype (M.190816), Rusinga Island.

Bull. B.M. (N.H.) Geol. 10, 8 PLATE 1

PIL AILS, 2

X1I°2 approx.
Anasinopa leakeyi gen. et sp. nov. Holotype (M.19081c), Rusinga Island.
Right mandible with C, P,-M3. Fic. 1. Occlusal aspect. Fic. 2. Lateral aspect.

Bull. B.M. (N.H.) Geol. 10, 8 PEATE 2

PLATE 3

XI*2 approx.
Dissopsalis pyroclasticus sp. nov. Holotype (M.19082), Kaboor.
Right mandible with P,-M,. Fic. 1. Occlusal aspect. Fic. 2. Lateral aspect.

Bull. B.M. (N.H.) Geol. 10, 8 PLATE 3

Fic.

Fie.

Fic.

PLATE 4

X1I‘2 approx.
Metapterodon kaisert Stromer. Right maxilla with P’-M8;
occlusal aspect. (CMF.4038), Karungu.

Metapterodon zadoki sp. nov. Right maxilla with M? 2; occlusal aspect.
Holotype (M.19094), Rusinga Island.

Pievodon africanus Andrews. Left maxilla with P4-M?;
occlusal aspect. (M.19090), Napak.

Leakitherium hiwegi gen. et sp. nov. Left maxilla with M! 2;

occlusal aspect. Holotype (M.19083), Rusinga Island.
Leahitherium hiwegi gen. et sp. nov. Left maxilla with P*M1};
occlusal aspect. (CMF.4025), Rusinga Island.
Hyaenodon (Isohyaenodon) andrewsi sp. noy. Right mandible
with M,-.; occlusal aspect. Holotype (M.15048), Ombo.

Bull. B.M. (N.H.) Geol. 10, 8 PLATE 4

PLATE 5

XI°2 approx.
Fic. 1. Hecubides euryodon gen. et sp. noy. Maxilla with P?—-M?; occlusal aspect. Holotype
(M.19084), Napak.
Fic. 2. Hecubides macyodon sp.nov. Left M ;occlusalaspect. Holotype (M.19086), Rusinga
Island.
Fic. 3. Kichechia zamanae gen. et sp. nov. Facial region of skull, left and right sides;
occlusal aspect. Holotype, Rusinga Island. Fic. 3a (M.19077a), Fic. 3b (M.190775).
Fic. 4. Metailurus africanus (Andrews). Facial region; occlusal aspect. (M.19076), Rusinga
Island.

Bull. B.M. (N.H.) Geol. 10, 8 PLATE 5

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BULLETIN OF

BRITISH MUSEUM (NATURAL HISTORY)
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DECHENELLID TRILOBITES >
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EDWIN BRIAN SELWOOD, Ph.D.

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Pp. 317-333 » 1 Plate ; 6 Text-figures

BULLETIN OF
THE BRITISH MUSEUM (NATURAL HISTORY)
GEOLOGY Vol. 10 No. 9
LONDON : 1965

THE BULLETIN OF THE BRITISH MUSEUM
(NATURAL HISTORY), «instituted im 1949, 1s
issued in five series corresponding to the Departments
of the Museum, and an Historical series.

Parts will appear at wrregular 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. Vol. 10, No. 9 of the Geological
(Palaeontological) series. The abbreviated titles of
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Issued November, 1965 Price Eleven Shillings

DECHENELLID TRILOBITES
FROM THE BRITISH MIDDLE DEVONIAN

By E. B. SELWOOD

CONTENTS
Page
I. INTRODUCTION : ‘ : ‘ 0 . : : : 319
Il, ACKNOWLEDGMENTS ‘ : : : : : : : 320
III. VARIATION . . : : : : . 0 : 0 321
IV. AGE OF THE Fauna. : . c : F ; . - 324
V. EcOLOGY AND DISTRIBUTION . : . 5 . 5 : 324
VI. SysTEMATIC DESCRIPTION : . : : : : : 326
VII. REFERENCES . b : : : c : 4 ; a 333
SYNOPSIS

Dechenella has a restricted occurrence in South West England. A single species only is known,
Dechenella (Dechenella) setosa Whidborne, 1889. This is redescribed and variation seen in the
pygidia and cranidia is examined. The species is bimorphic, each bimorphic group of pygidia
showing a range of variation that can be correlated with size and hence presumably with age.
The species is probably of late Couvinian age.

I. INTRODUCTION

ALTHOUGH Dechenella is a characteristic Middle Devonian genus with a wide distri-
bution, relatively few species are known, and in Britain only one species, Dechenella
setosa, has been recognised. This species, unknown outside Devonshire, was first
described by Whidborne (1889, 1889a) from the Middle Devonian Limestones at
Chercombe (sometimes spelt Chircombe or Cherecombe) Bridge near Newton Abbot,
and subsequently redescribed by Richter (1912). Much of the museum material is
incompletely localized but from the lithologies it seems that, with rare exceptions,
all comes from an extensive disused quarry on the north bank of the River Lemon,
200 yards east of Chercombe Bridge (National Grid Reference: SX832711), where
70 feet to 80 feet of well bedded limestones are still exposed. The individual lime-
stone beds, which vary in thickness from a few inches to several feet, are dominantly
pale grey in colour and yield a fauna of brachiopods, corals, stromatoporoids and
polyzoa. In the higher structural horizons of the quarry there are, interbedded with
these pale limestones, horizons of dark bituminous limestone (which are no doubt
the “black marbles’ yielding trilobites mentioned by Whidborne 188ga: 28).

320 BRITISH DEVONIAN DECHENELLID TRILOBITES

Recent collecting in this quarry has failed to produce any trilobites from the pale
coral limestone, but much new material has been obtained from one horizon, 12
inches thick, of black fine-grained limestone exposed in an overgrown section at the
entrance to the quarry, a few yards east of the old lime kiln. This is a lithology
identical to that of the museum material, and there seems no reason to doubt that
the earlier collectors found a similar restricted distribution of trilobites. Two speci-
mens in the British Museum (Natural History) are labelled ‘““West Hill, East Ogwell’’
and were probably collected from the largely overgrown quarry south-east of Cher-
combe Bridge. Searchingin this quarry has yielded a further pygidium froma lithology
identical to that in the Chercombe Bridge Quarry. The West Hill quarry lies only
100 yards along the strike from the latter quarry, and it is most likely that the same
horizons are represented in both quarries.

A significant difference exists between the old collections and those made recently ;
Whidborne based his description of the species upon 37 pygidia and 2 cranidia, and
in all the museum material examined a preponderance of pygidia exists, but recent
collecting has demonstrated that pygidia and cranidia occur in approximately equal
numbers. This strongly suggests bias in the original collecting. As the material is
sparsely distributed through the rock, it is likely that much of it was collected by
workmen in the quarry as chance finds came to light. Such collecting would undoubt-
edly be biased in favour of “‘attractive’” specimens; in this case, the perfectly pre-
served pygidia certainly catch the eye much more readily than the dissociated
cranidia and free cheeks.

Sufficient material is now available to show that there is, particularly in the
pygidia, a considerable variation of morphological features. Although comparisons
of extreme variants might suggest that more than one species is involved, the
variation appears to be continuous and there is no reason to suspect the presence of
more than one species. The sample is interpreted as an assortment of individuals of
different ages, since it is most unlikely that any of the material was collected
through a considerable thickness of sediment.

There is a notable absence of larval and small specimens in the museum material,
and a similar gap has been found in recent collecting. This suggests that their
absence is to be accounted for by some ecological factor, and that only adults
migrated into the area.

Since the published descriptions do not take account of the variation, and particu-
larly since the pygidium described by Richter (1912) is not characteristic, the
variation of Dechenella setosa is first described and the species then redefined in
more general terms.

Il. ACKNOWLEDGMENTS

I wish to thank particularly Dr. W. T. Dean and Professor S. Simpson, who
read and criticized the original manuscript, and Mr. J. Saunders, technician in the
Department of Geology at Exeter, who rediscovered the trilobite band and gave
valuable assistance in subsequent collecting. Mr. Saunders is also responsible for the
photographs.

BRITISH DEVONIAN DECHENELLID TRILOBITES 321

Dr. R. C. Blackie (Exeter City Museum), Mr. A. G. Brighton (Sedgwick Museum,
Cambridge), Dr. W. T. Dean (British Museum (Natural History)), Dr. J. D. D. Smith
(Geological Survey and Museum), and Dr. F. S. Wallis (Torquay Natural History
Museum) kindly permitted the examination and arranged the loan of specimens in
their care. Dr. W. Struve allowed me to see type material of Continental species
held in the Senckenberg Museum, Frankfurt-am-Main. This part of the work was
completed whilst in receipt of a travel grant from the British Council; this is gratefully
acknowledged.

III. VARIATION

Measurements have been made on the pygidia of 44 specimens and, where possible,
four standard measurements taken; the breadth of pygidium (Bp), the breadth of
axis (Ba), the length of pygidium (Lp), and the length of axis (La) (Text-fig. 1,
Table I).

TABLE I
Standard
Mean Deviation
Breadth of pygidium 16:79 + 1'479 4°89
Length of pygidium 12:04 + 1:026 3°39
Breadth of axis 4°31 + 0-368 TIO.
Length of axis 10°43 + 0°884 2:92

All measurements in millimetres

lg
La

ie Bp a

inde ast

!
Fic. 1. Standard measurements of cranidia and pygidia of Dechenella setosa. Bc, breadth
of cranidium; Bg, breadth of glabella; Lc, length of cranidium; Lg, length of glabella.
Bp, breadth of pygidium; Ba, breadth of axis; Lp, length of pygidium; La, length of axis.

322 BRITISH DEVONIAN DECHENELLID TRILOBITES

Frequency diagrams of dimensions and ratios of different dimensions are con-
sistent with the hypothesis that all specimens can be referred to a single species,
since each shows a single well defined peak.

20 20 20

15 154 hs 15
E E E
= €
E € E
¢ c s
4 a 10
° 10 a 10 5
5 54 5
y= 2-42x-0-04 y= 1-17x - 0-13 y=2:78x+0-05
2 4 6 8 ae 10 15 2 4 6 8
Ba (in mm) La (in mm) Ba (in mm)
= 4 x = b = 5} Q = 4!
Fic. 2. Scatter diagrams showing variation in pygidia of Dechenella setosa.
The reduced major axis is included for each scatter.
3074 304 30
254 254
204 se
E E €
iS E is
E154 s oy S
Q
a a a
104 104
sy |
y=1:44x- 0-86 " y=1-69x - 0-88 y= 4:02x -0:53
5 10 15 20 5 10 15 2 4°68
Lp (in mm) La (in mm) Ba (in mm)
= 1 x 2s Aes

Fic. 3. Scatter diagrams showing variation in pygidia of Dechenella setosa.
The reduced major axis is included for each scatter.

BRITISH DEVONIAN DECHENELLID TRILOBITES 323

Scatter diagrams (Text-figs. 2, 3) relating the length of the standard measurements
show, on arithmetic co-ordinates, a markedly rectilinear distribution. The reduced
major axis (y=b+kx) has been drawn for all scatters (see Miller & Kahn 1962 : 204),
and these clearly indicate that the sample may be interpreted as a single species
showing isometric growth. In the absence of young and larval specimens, it is not
possible to state the course of the reduced major axis when extrapolated downwards
into the smaller size ranges, but from the known ontogenies of trilobites (Palmer
1958) it is probable that the growth here is allometric.

TABLE II

Standard Standard Dispersion

Reduced Correlation evvor of evvoy of avound No. of

major axis coefficient slope intercept R.M.A.* specimens
Lp/Bp I°44x —o-86 0:94 0:076 0:095 2:062 42
Ba/Lp 2:78x +0:05 0:94 O-141 0-634 I'205 42
Ba/Bp 4°02X —0°53 0-89 0-187 1:287 2°399 42
Ba/La 2°42K —0-04 0:90 0-160 0-174 1°387 44
La/Lp I'I7xX —O'13 0-99 0:024 0:256 0°589 42
La/Bp I-69x —o0:88 0:92 0:090 1'033 2:091 42

* R.M.A. — Reduced major axis

When the detailed characteristics of the pygidia are examined, much variation
can be observed which is closely related to the size, and hence presumably to the
age, of the individuals. At the same time, the sample falls into two groups of approxi-
mately equal number, each showing the variation suggested to be associated with
age. The two groups may be distinguished by the character of the axial furrows:
in Group A they are weakly constricted between rings 7-8, whilst in Group B they
are straight (Text-fig. 4). The measured characters of the pygidium are quite
independent of the bimorphic characters, specimens referred to Groups A and B
show a random distribution within all of the scatters prepared in Text-figs. 2 and 3.

Bimorphic variation has also been recorded amongst the cranidia. The glabellas
of specimens referred to Group C are more pointed than those of Group D, and 8 on
the anterior branch of the facial suture is placed more anteriorly in Group C than
in Group D. In side view, the occipital ring is seen to lie below the level of the
glabella in Group C, whilst it reaches the height of the posterior part of the
glabella in Group D. Ornamentation in the form of a fine granulation has only
been observed on the glabella of specimens belonging to Group D (Text-fig. 5).

The bimorphism described above is probably sexual but the lack of complete
specimens makes it impossible to determine if a correlation exists between the
bimorphism seen in the pygidia and cranidia. When comparisons are made with
other species (page 331) it is found that, although the range of variation of Dechenella
setosa would appear to include a number of species, there is some correlation between
those features which distinguish the bimorphic individuals of Dechenella setosa, and
those which distinguish the species Dechenella vernemili and Dechenella nittbergensis.

324 BRITISH DEVONIAN DECHENELLID TRILOBITES

It is thus tempting to ascribe the cranidium D to pygidium A (both showing verneuila
characters) and cranidium C to pygidium B (both showing r7ttbergensis characters).
Verification can only await the discovery of complete specimens.

: (coal)
a (my)

Fic. 4. Pygidia of Dechenella setosa. Group A. (a) Plan view, note constricted axis; (b) Side
view; (c) Posterior view. Group B. (d) Plan view, note straight axis; (e) Side view; (f)
Posterior view.

Both pathological and cicatrized pygidia have been observed in the sample, and
it is evident that the species possessed considerable powers of regeneration
(BIS, fie 8):

IV. AGE OF THE FAUNA

Both Calceola sandalina (Linné) and Strvingocephalus burtint Defrance have been
recorded from the Chercombe Bridge Quarry (Ussher 1913 : 20). Although neither
has been positively identified during the present investigation, Middleton (1959)
has confirmed that the limestones are at least in part of middle Middle Devonian age.

Richter (1912) suggested that Dechenella setosa was of Givetian age, and this is
supported by the acknowledged Givetian age of all the closely related species.
However, Scutellum (Scutellum) flabelliferum (Goldfuss) also occurs in the same
horizon; this trilobite is a characteristic Couvinian form. A somewhat stronger case
can thus be made out for a Couvinian age, though the presence of Sivingocephalus
burtimt in the same quarry must indicate an horizon near to the Couvinian/Givetian
boundary.

The limestones of the quarry have so far failed to yield conodonts.

V. ECOLOGY AND DISTRIBUTION

Since the trilobites are restricted to the black limestone, it seems that sea floor
conditions controlled their distribution and that the species was benthonic. The
fine-grained bituminous character of the limestone, the presence of pyrite and the
great reduction of coral and stromataporoid growth suggest bottom sediments

BRITISH DEVONIAN DECHENELLID TRILOBITES 325

Fic. 5. Cranidia of Dechenella setosa. Group C. (a) Plan view, anterior of glabella pointed;
(b) Side view, occipital ring low ; (c) Anterior view. Group D. (d) Plan view, glabella
rounded anteriorly, posterior surface of glabella granulated; (e) Side view, occipital ring

high; (f) Anterior view.

containing a considerable amount of decaying organic matter; such an environment
would be well-suited to mud feeding organisms. The absence of young and larval
stages from the sample might be explained by these stages being planktonic and
settling on to the sea floor only on reaching maturity. Small thin shelled bivalves
and the trilobite Scutellum (Scutellum) flabelliferwm occur together with the dechenellid
trilobites. Scutellum occurs in a wide variety of lithologies in the Torquay district
and was probably planktonic. The distribution of the fauna would not seem to be
entirely dependent upon ecological conditions, for comparable lithologies to that
yielding the dechenellid trilobites exist both in the Chercombe Bridge Quarry and in
many of the other Middle Devonian Limestone outcrops in the South Devon area.
To some extent the localization of the fauna may be more apparent than real in
that much collecting remains to be done, but at the same time the main limestone
outcrops have been extensively quarried in the past and it is surprising that more
specimens have not come to light.

The variation seen in Dechenella setosa does not suggest that the British species
evolved in isolation, for it shows a range of variation allowing close comparisons to
be made with species described from the Rhenish Mountains, Morocco, and Bohemia
(page 331). It is suggested that the centre of dispersal of European Middle Devonian
dechenellids lay some distance outside the British area and that the record at
Chercombe Bridge represents an isolated and unusual migration into the British

326 BRITISH DEVONIAN DECHENELLID TRILOBITES

area. Since the adult specimens of Dechenella setosa were probably benthonic, the
isolated occurrence might be explained by the chance distribution of planktonic
larvae in currents.

Vi; SYSTEMATIC DESCRIPTION

Family PROETIDAE Salter 1864
Subfamily DECHENELLINAE Pribyl 1946
Genus DECHENELLA Kayser 1880
Subgenus DECHENELLA Kayser 1880

Dechenella (Dechenella) setosa Whidborne
(Pl. 1, Text-figs. 1-6)

1889 Dechenella setosa Whidborne: 29.

1889 Dechenella setosa Whidborne: 27, pl. 2, figs. 15-17.

1912 Dechenella (Eudechenella) setosa Whidborne; Richter : 310, pl. 20, figs. 8, 9.
1950 Dechenella (Dechenella) setosa Whidborne; Richter, R. & E.: 178.

Dracnosis. A bimorphic species of Dechenella with weakly impressed glabellar
furrows. The frontal area is large and more than one quarter of the total length of
the glabella at the sagittal line. The anterior border is broad. Specimens of
Group C are distinguished from those of Group D by their smooth, more pointed
glabellas. The axis of the pygidium is narrow and constricted between rings 7 and 8
in Group A, but straight in Group B. The length of the pygidium is more than
three fifths of its maximum breadth. 18 rings and 12 ribs may be distinguished
clearly. The pleural furrows are narrow and deep anteriorly but they shallow and
widen posteriorly.

Lectotype. Cephalon (BM., I. 5039). Pl. 1, fig. 14. Designated by Richter,
R. & E. (1950).
LocaLity AND Horizon. Chercombe Bridge Quarry (Nat. Grid Ref. SX832711),
near Newton Abbot, Devon; Middle Devonian, probably late Couvinian.
ADDITIONAL MATERIAL. The following specimens exemplify the characteristic
features of each of the four groups of Dechenella setosa described in this paper:
Group A, GSM.6987 (PI. 1, figs. 1-3); Group B, BM., I. 5056 (Pl. 1, figs. 5-7);
Group C, BM., I. 5039 (PI. 1, fig. 14); Group D, BM., IT.1o1 (PI. 1, fig. ro).

DESCRIPTION

Cramdium. Side view. The glabella is broadly curved. From the crestal point,
lying one third of the distance from the glabella posterior to the glabella anterior,
the glabella descends quite steeply to the pre-glabellar field, but rather more steeply
in Group D than in Group C. The preglabellar field declines gently forwards and

BRITISH DEVONIAN DECHENELLID TRILOBITES 327

passes into a broadly concave anterior border furrow. The anterior border is gently
inflated and rises at a low angle from the border furrow, but then falls sharply to the
margin. The occipital furrow is deep and rounded and passes posteriorly into a
symmetrical and flattened occipital ring. This ring continues the curve of the
glabella in Group D but falls slightly below this in Group C. In sectioned material,
the posterior border of the occipital ring is seen to be reflexed onto the ventral surface
and is carried forward for a distance equivalent to half the length of the occipital
ring.

Frontal View. In profile, the glabella is weakly triangular and rises gently and
regularly from poorly defined axial furrows to the sagittal line. The weak keel so
developed is more evident in Group C than in Group D. The palpebral lobes are
broad and flat.

Plan View. The glabella, which is slightly longer than its maximum breadth,
is weakly trefoiled, being constricted at 2p in Group C and at 3p in Group D. The
anterior part of the glabella is broadly rounded and well defined in Group D but
tapers rather more sharply in Group C and reaches slightly farther to the anterior
margin. The maximum glabellar breadth is measured from 5-6, thereafter the
glabella narrows slightly to the occipital furrow. Four lightly impressed glabellar
furrows are recognisable on the dorsal exoskeleton. Ip is most strongly developed;
it has a broadly arcuate course from a position somewhat anterior of the mid-point
of the palpebral lobe, towards a point on the occipital furrow rather more than two
thirds of the distance from the axial furrow to the sagittal line. Approximately
half the distance along its course, the furrow curves more sharply towards the
posterior; at this point a weak fork can be distinguished in some specimens, in
others a faint pit can be seen on the line of, but separate from, the anterior section
of 1p. The glabellar furrow 1p shallows noticeably towards, and fails to reach,
both the occipital and axial furrows. 2p is less clearly impressed and runs parallel
to the anterior section of 1p. 3p runs parallel to 2p; it is short and frequently just a
faint mark on the glabella. 2p and 3p fail to reach the axial furrows. The distance
between Ip and 2p is one and a half times greater than that between 2p and 3p.
4p appears as a shallow depression and can only be recognised on large specimens.
A weak keel extends along the sagittal line from the posterior border of the glabella
for a distance approaching one third of the total glabellar length. The occipital
furrow is deep and narrow. It is arched forwards medianly and terminated laterally
in deeply impressed pits, which are placed on the line of the axial furrow and
orientated oblique to the occipital furrow. The occipital ring is a flat band marked
by a small mesial tubercle. This ring averages one tenth of the total sagittal length
of the cranidium. The frontal area is more than one quarter of the total sagittal
length of the cranidium. The preglabellar area is smooth and slopes gently to a
well defined anterior border furrow and is continued into the anterior area of the
fixigena as a broad smooth surface sloping to the anterior border. The palpebral
area is broad and flat and the posterior area of the fixigena is small. The anterior
margin of the border is broadly curved; the anterior facing part of the border is
marked by three to four discontinuous terrace lines, whilst the posterior part is

328 BRITISH DEVONIAN DECHENELLID TRILOBITES

smooth and gently declined to border furrow. In Group D the border is larger than
in Group C. The anterior branch of the facial suture diverges from the glabella at
angles varying between 30°—-40°. y is rounded and placed opposite to glabellar
furrow 3p, and is clearly separated from the axial furrows. 8 is evenly rounded in
Group D, where it is positioned level with the anterior border of the glabella on the
line of the anterior border furrow. The palpebral lobe is long and flattened. 3 is
rounded and placed at approximately the same distance from the sagittal line as 8.
¢ lies farther from the axial furrow than y and is situated at a distance from the
sagittal line approximating to half the maximum glabellar width. The posterior
branch of the suture is short and turns sharply outwards at ¢ until a distance from
the median line similar to that of 3 is reached; it then runs broadly parallel to the
posterior border of the cranidium and eventually cuts the border at a distance from
the axial furrow approximately equal to half the width of the occipital ring. The
posterior border is broadly rounded to flattened, and its length (sag.) approximates
to half that of the occipital ring. The internal mould is imperfectly known, but the
glabellar furrows are broader and more clearly impressed than on the dorsal
exoskeleton.

Librigena. The cheek area is moderately inflated and slopes more steeply to the
posterior border furrow than to the lateral border furrow. The eye platform widens
laterally and to the posterior, but it is generally poorly defined. A broad but shallow
lateral border furrow defines the lateral border. This border is triangular in cross
section; the outward facing surface is steeper than that facing inwards and is orna-
mented by four to five discontinuous terrace lines. The posterior border furrow,
which has an open V-shaped cross section, unites with the lateral border furrow and
continues for a short distance into the genal spine. The posterior border is only
weakly inflated, and about two thirds of the width of the lateral border. The genal
spine is short (about one half the maximum breadth of the librigena) and sturdy,
being ornamented by two to three fine lines. The eye, which is large and crescentic,
rises more steeply from the cheek area posteriorly than anteriorly. Its visual surface
is smooth, and evenly convex and is separated from the cheek area by a weak groove.
The doublure is flat and its breadth is comparable to that of the lateral border.
Its surface is irregularly pitted and ornamented by six fine lines parallel to the margin
of the cheek. The free border of the doublure is slightly recurved dorsally.

Pygidium. Plan View. In outline, the pygidium is longitudinally elliptical but
specimens of Group A are more rounded than those of Group B. The length of the
pygidium is more than three fifths of the breadth, and the axis is narrow, ranging
between one fifth and one third of the pygidium breadth. In Group B, the axis
narrows evenly between straight axial furrows, but it constricts slightly between
rings 7 and 8 in Group A. The posterior termination of the axis is rounded and
reaches to the border furrow in small specimens of both groups, but it becomes pro-
portionately shorter with the increase in size and then stands clear of the border.
18 (+2) rings may be recognised, of these 14-15 are clear for the posterior segmenta-
tion is indistinct. Narrow ring furrows reach to the axial furrows in segments 1-8,
but thereafter they weaken at the axial furrows and become less distinct. The dorso-

BRITISH DEVONIAN DECHENELLID TRILOBITES 329

lateral parts of the rings are marked by weak longitudinal notches which define a
weakly inflated area. These notches are deepest at the anterior border of the rings,
and shallow rapidly to the posterior and do not affect the posterior border. Longi-
tudinal grooves produced by the notches are developed with varying intensity; they
are best shown in small specimens, particularly those of Group B. Rings of the
larger specimens are more characteristically narrow flattened bands.

I2 (+2) weakly S-shaped ribs may be recognised; of these 8-9 are clear. The
pleural grooves of ribs 1-4 are well defined, narrow and deep, and reach almost
from the axial furrow to the border. Thereafter the grooves become progressively
less well defined, shallower and broader and fail to reach to the border furrow. All
of the anterior ribs are notched at the border. Smaller specimens show ribs with
flattened to broadly rounded cross section, but the ribs of larger specimens are
triangular in cross section and show crestal lines either medianly or slightly posteriorly
placed, and with a steeper fall to the posterior pleural furrow than to the anterior.
This crestal line may be traced from the axial furrow across the flattened section of
the pleural lobes. Interpleural furrows are faint, and not always recognised on all
ribs; their presence has been recorded up to rib 8. The furrows which are medianly
or slightly posteriorly placed on the rib are clear at the axial furrow but become
less well defined towards the periphery. The border is flattened to weakly convex,
and declines towards the margin. Initially narrow, it widens posteriorly and attains
its maximum width at rib 5. In Group A, this width is maintained, but in Group B
the maximum width of the border is attained at the posterior lateral part of the
pygidium. The border furrow is only weakly developed.

Posterior View. In Group B, the axis shows a semicircular cross section in
specimens of small and intermediate size, but the section becomes more gently
convex in large specimens. In Group A, the axis is more nearly semi-circular at all
sizes. The flanks are strongly rounded in all small specimens but they become
distinctly flattened with increased size in Group B. Group A is more strongly rounded
at all sizes. The border slopes gently to the periphery and is differentiated from the
pleural lobes only by a weak concavity.

Side View. The axis curves gently down from the anterior to the posterior;
occasionally the anterior part of the axis is rather flattened. All of the rings decrease
in size posteriorly. The articulating half ring is distinct but narrow and the articulat-
ing furrow is sharp. The first 5-6 rings are clear in this view and are separated by
deeply impressed ring furrows; the individual rings are planar and slope anteriorly
to the preceding ring furrow. Thereafter the rings are flat and the ring furrows
scarcely impressed. The border is clearly marked off from the axis by a well defined
re-entrant angle. In young specimens the border slopes to the margin at an angle
of 45°. This slope decreases and flattens in adult specimens of both Groups A and B.

The doublure is narrow and increases in breadth from the anterior margin of the
pygidium towards the posterior, but it is weakly constricted postaxially. Its structure
is continuous with the dorsal exoskeleton both at the periphery of the pygidium and
at its anterior margin. The inner margin is free but closely applied to the ventral
surface. Anteriorly the doublure is strongly inflated and evenly rounded but it

330 BRITISH DEVONIAN DECHENELLID TRILOBITES

becomes somewhat flattened towards the posterior. The surface of the doublure is
ornamented by 7-8 terrace lines but it is not pitted or granulated.

Internal Mould. The rings are narrow and sharp and separated by wide deep
furrows which decrease in intensity towards the posterior; all of the furrows are
much clearer than the comparable furrows on the dorsal exoskeleton. The ribs are
narrow and angular and appear as furrowed ridges between broad, deep pleural
furrows. All of the ribs are much clearer and the posterior ribs extend further
towards the border than on the dorsal exoskeleton. The border is clearly defined,
smooth and flat.

Ornamentation. With the exception of the furrows, a fine pitting has been
recorded on all parts of the cranidium; this being most strongly expressed on the
median parts of the glabella. The pitting of the fixed cheeks and the border is fine
and irregular and not clearly defined below magnifications of «20. No granulations
have been recorded in specimens referred to Group C, but a collection of pustules
grouped at the posterior end of the glabella characterises Group D. At lower
magnifications the free cheek is smooth, but at x 20 the surface is seen to be finely
and irregularly pitted.

With the exception of the furrows, all dorsal surfaces of the pygidium are pitted.
The pits on the rings are considerably finer than those on the pleural lobes, where
they are usually, but not invariably, arranged in two rows either side of the inter-
pleural furrow. The pits of the border are evenly distributed. The rings and border
are normally finely granulated. The intensity of granulation is variable; on the ribs
it is normally confined to that part of the rib posterior to the interpleural furrow,
and most strongly developed on the outer two thirds of the ribs. The granulation
of the border is also of variable intensity ; normally the greatest concentration of
granules is on the posterior-lateral part of the border. A few specimens in both Groups
A and B appear to be completely smooth. Delicate, frequently sigmoidally shaped,
raised lines ornament the steeper peripheral part of the border. These are oblique
to the margin and usually more or less parallel to the sagittal line. Rarely the raised
lines branch. Posteriorly the raised lines come to lie progressively more nearly
parallel to the margin of the tail, and where preservation is complete run parallel
to the margin of the tail at its extremity.

The ventral surface of the dorsal exoskeleton is smooth at low magnifications but
a fine granulation of the surface can be seen at 30.

MEASUREMENTS (in mm.) GSM.6987.— BM. I. 5056

Length of pygidium 14:0 12:0
Breadth of pygidium 175 145
Length of axis Tees 10:25
Breadth of axis 5:0 4:0

BM.,1I.5039 BM.,IT.101 BM.,IT.102
Length of cranidium 14:0 (est.) 6:5 7°5
Breadth of cranidium 10-0 (est.) 5:0 6:0
Length of glabella 9°75 3°75 4°75
Breadth of glabella 8-0 3:0 4:0

Breadth of cephalon 22:0

BRITISH DEVONIAN DECHENELLID TRILOBITES 331
(a) (b)

Lp (in mm)
Bp (in mm)

0 5 10 15
La (in mm) Ba (in mm)
4 D. verneuili 6 D. rittbergensis
° D. gigouti e D. struvei

Fic. 6. Scatter diagrams showing variation in some Continental species of Dechenella. The
appropriate reduced major axis for Dechenella setosa has been added to each scatter.

COMPARISONS WITH OTHER SPECIES. Arguments have been advanced in the fore-
going pages in support of the contention that the specimens from Devonshire con-
stitute a single bimorphic species with a wide range of variation. The variants of
Dechenella setosa show many similarities to Continental species of Givetian age,
and a close relationship is indicated. However, the fine and precise differences which
separate these species make comparisons exceedingly difficult. Characters said to
be diagnostic occur in varying combinations in the British material. This could
have suggested, had less material been available, that several new species are
represented. The pygidia of Dechenella setosa may be compared most closely to
Dechenella verneuili (Barrande), Dechenella rittbergensis Zimmerman and Dechenella
gigoutt R. & E. Richter, but no single pygidium can be found which agrees exactly
with the diagnoses given for these species. Scatter diagrams (Text-fig. 6) prepared

332 BRITISH DEVONIAN DECHENELLID TRILOBITES

from the published measurements, and measurements taken from the figures of the
above species show a marked rectilinear distribution. This suggests that the species
may be conspecific, and that future collecting may reveal a wider range of variation
than has previously been suspected. A close relationship also exists between these
scatters and those prepared for Dechenella setosa, for they all fall within the observed
range of the British species. This is apparent on the scatter diagrams (Text-fig. 6)
where the appropriate reduced major axis for Dechenella setosa has been added.
Text-figure 6a is included as an example of a close correlation between the reduced
major axis of Dechenella setosa and the scatter of the Continental species. Text-fig. 60
is included as an example with less perfect fit. Thus, it may prove difficult to separate
these species of Dechenella in the future. Meanwhile, some of the more significant
differences between Dechenella setosa and the published descriptions of other species
are noted.

The number of ribs and rings present in the pygidia of Dechenella setosa is com-
parable to that in Dechenella rittbergensis, the number being distinctly higher than
that of the other species. The shape of the pygidium, rather blunted and broadly-
rounded posteriorly, is said to be closely comparable to Dechenella gigouti (Richter,
R. & E. 1950). Although there is a similarity between Dechenella gigouti and the
pygidium of Dechenella setosa figured by Richter (PI. 1, figs. 5-7), this particular
shape is distinctly unusual in the sample; by far the more common shape is that
ascribed to Dechenella vernewilt. Similarly, the very broad border of Dechenella
gigoutt is not characteristic of Dechenella setosa, though variants with moderately
broad border, as figured by Richter, do exist.

The outline of the pygidium both in cross and long section, which is specifically
important in other described species, is found to vary with size in Dechenella setosa.
Unlike Dechenella rittbergensis the axis is normally separated from the post axial
region by a clear re-entrant angle. The cross section of the ribs also varies with size;
the rounded ribs (characteristic of Dechenella vernewilt) are most common in small
specimens, whilst those with a more flattened section (characteristic of Dechenella
viltbergensis) and triangular section (characteristic of Dechenella struver R. & E.
Richter) typify the larger specimens.

The granulated surface of the test of Dechenella setosa would appear to distinguish
the species from Dechenella vernewili and Dechenella rittbergensis which are essentially
smooth forms; however, occasional smooth forms occur in both Groups A and B.
Those specimens of Group A can be said to show a “vernewili trend’’, for this group
has the constricted axis characteristic of Dechenella verneuili: the smooth forms of
Group B, which have straight axial furrows can likewise be said to show a “‘vzttber-
gensis trend’. There is no regular variation of test pitting, such as has been used
to distinguish between Dechenella rittbergensis and Dechenella vernemli.

The cranidia may be compared most closely to Dechenella gigouti, Dechenella
rittbergensis and Dechenella vernewili. The broad frontal area is characteristic and
serves to distinguish the species from Dechenella nittbergensis and Dechenella verneutlt,
but is less broad than that observed in Dechenella gigouti, where the length of the
frontal area is equal to half the glabellar length. The presence of terrace lines on the

BRITISH DEVONIAN DECHENELLID TRILOBITES 333

anterior border and the pitting of the surface serve to distinguish Dechenella setosa
from Dechenella gigouti, which lacks both these features.

Apart from the broad border, specimens referred to Group C appear superficially
like Dechenella rittbergensis but the glabella is less pointed and the glabellar furrows
are less clearly defined. Group D, on the other hand, is more comparable to Dechenella
vernewilt but the glabella is less broad and the glabellar furrows run broadly parallel
to one another.

With the knowledge of the variation in Dechenella setosa, it is tempting to suggest
that Dechenella rittbergensis and Dechenella vernewli represent bimorphic forms of
the same species, but the geographical separation of localities yielding these species
renders this improbable.

VIL. REFERENCES

Kayser, E. H. E. 1880. Dechenella, eine devonische Gruppe der Gattung Phillipsia. Z. disch.
geol. Ges., Berlin, 32 : 703-707, pl. 27.

Mrippieton, G. V. 1959. Devonian tetracorals from South Devonshire, England. J. Paleont.
Tulsa, 33 : 138-160, pl. 27.

Mirter, R. L. & Kaun, J.S. 1962. Statistical Analysis in the Geological Sciences. xiii + 483 pp.
New York & London.

Patmer, A. R. 1958. Morphology and Ontogeny of a Lower Cambrian ptychoparioid trilobite
from Nevada. J. Paleont., Tulsa, 32 : 154-170, pls. 25, 26.

PRIBYL, A. 1946. Notes on the recognition of the Bohemian Proetidae (Trilobitae). Bull.
int. Acad. tchéque Sci., Prague, 46 : 91-131, pls. 1-4.

RicHTER, R. 1912. Beitrage zur Kenntnis devonischer Trilobiten. 1. Die Gattung Dechenella
und einige verwandte Formen. Abh. senckenberg. naturf. Ges., Frankfurt a.M., 31 : 239-340,
pls. 18-21.

RIcHTerR, R. & E. 1950. Arten der Dechenellinae (Tril.). Senchenbergiana, Frankfurt a.M.,
31 : 151-184, pls. 1-4.

SALTER, J. W. 1864. A Monograph of the British Trilobites from the Cambrian, Silurian, and
Devonian Formations, 1 : 1-80, pls. 1—6. Palaeontogr. Soc., [(Monogy.], London.

UssHer, W. A. E. 1913. The Geology of the Country around Newton Abbot. Mem. Geol,
Surv. U.K., London. vi + 149 pp., 3 pls.

WHIDBORNE, G. F. 1889. On some Devonian Crustacea. Geol. Mag., London (3) 6 : 28-29.

1889a. A Monograph of the Devonian Fauna of the South of England, Vol. 1. The fauna

of the Limestones of Lummaton, Wolborough, Chircombe Bridge, and Chudleigh,

Pt. 1 : 1-46, pls. 1-4. Palaeontogr. Soc., (Monogr.], London.

PLATE 1

Fics. 1-4. Dechenella (Dechenella) setosa, Whidborne. Group A. Pygidium (GSM.
6987). 1, Plan view, axial furrows weakly constricted, x2.3 2, Side view, X2.3
3, Posterior view, xX2.3 Pygidium (TM., B.490). 4, Plan view, x1.8

Fics. 5-9. Dechenella (Dechenella) setosa, Whidborne. GroupB. Pygidium(BM., 1.5056).
5, Plan view, axial furrows straight, x2.3 6, Side view, x2.3 7, Posterior view, x2.3
Pygidium (BM., I. 5050). 8, Plan view, cicatrized specimen. Wound has caused axis
to grow asymmetrically, x 2.3
Pygidium (BM., I. 1110a). 9, Plan view, large specimen showing prominent crestal lines
on ribs, x1.8

Fics. 10,11. Dechenella (Dechenella) setosa, Whidborne. Group D. Cranidium (BM.,
IT. ror). tro, Plan view, 5.5 Cranidium (BM., IT. 104). 11, Plan view, x4.1

Fics. 12,13. Dechenella (Dechenella) setosa, Whidborne. Group C. Cranidium (BM.,
IT. t02). 12, Plan view, x2.3 Cranidium (BM., IT. 103). 13, Plan view, x4.1

Fic. 14. Dechenella (Dechenella) setosa, Whidborne. Group C. Cephalon (BM., I. 5039).
Plan view, x1.4 Lectotype.

Fic. 15. Dechenella (Dechenella) setosa, Whidborne. Free Cheek (BM., IT. 105), x5.5

All specimens whitened with ammonium chloride before photographing. Specimens with
numbers prefixed BM., GSM. and TM. are housed respectively in the British Museum (Natural
History), London, the Geological Survey & Museum, London, and the Torquay Natural History
Museum.

Bull. B. M. (N. H.) Geol. 10, 9 BERATED 1

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CRETACEOUS AMMONITES AN
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CRETACEOUS AMMONITES AND
NAUTILOIDS FROM ANGOLA

BY
MICHAEL KINGSLEY HOWARTH, Ph.D.

Ph. 335-412 ; 13 Plates ; 23 Text-figures

BULLETIN OF
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CRETACEOUS AMMONITES AND
NAUTILOIDS FROM ANGOLA

By MICHAEL KINGSLEY HOWARTH

CONTENTS

Page
I INTRODUCTION ; p : : . é : < ‘ 339
II AMMONITE FAUNAS OF THE MARINE CRETACEOUS OF ANGOLA. 6 340
(a) Mogamedes basin . : c 0 : : : é 341
(b) mae and Cuanza basins . : : : : : 341
. Albian . : : 6 : : : : 341
De Canemanicin Seintionten : j : : ; ‘ 342
3. Campanian and Maastrichtian . : 3 é : 342
Ill canes DESCRIPTIONS : : : : 343
Family DOUVILLEICERATIDAE Dao & Wonencl F : : 343
Genus Douvilleiceras Grossouvre. 343

Douvilleiceras mamnullatum (Schlotheim) ? var. LUCE
nodum (Quenstedt) . ; 6 5 : 343
Douvilleiceras orbignyt Hyatt : : : : 345
Family BRANCOCERATIDAE Spath . c 5 : : : 346
Subfamily Brancoceratinae Spath ; ; 3 a : 346
Genus Neokentrocevas Spath . . > : 2 : 346
Neokentroceras curvicornu Spath . : : : 348
Neokentroceras singulave Haas 5 : : : 350
Neokentroceras subtuberculatum Spath . 4 : 351
Neokentroceras trituberculatum sp.nov. . : ; 352
Neokentroceras pseudovaricosum Spath . 5 i 353
Neokentroceras cvassicostatum sp.nov. . j 3 355
Family PHYLLOCERATIDAE Zittel . ‘ : 0 : 0 356
Genus Neophylloceras Shimizu : 0 é : : 356
Neophylloceras ultimum Spath 5 : . : 356
Family TETRAGONITIDAE Hyatt . : 6 . c : 357
Subfamily Gaudryceratinae Spath : 2 : . c 357
Genus Anagaudryceras Shimizu : : ‘ 5 357
Anagaudryceras mikobokense Collignon : : : 358
Genus Gaudryceras Grossouvre : , : : : 360
Gaudryceras vavagurense Kossmat . ; , : 361
Family BACULITIDAE Meek . : 5 . 9 é : 362
Genus Baculites Lamarck , : 6 5 0 é 362
Baculites anceps Lamarck . 2 : : 0 363
Baculites subanceps Haughton 0 : : : 368
Family NOSTOCERATIDAE Hyatt . : ; : ; : 371
Genus Didymoceras Hyatt ; ; é j : 374
Didymoceras subtuberculatum sp.nov. . : 6 374
Didymoceras cf. californicum Anderson . c ; 376
Didymoceras cf. hoynbyense (Whiteaves) . : : 377

Didymoceras cf. angolaense (Haughton) . 6 : 378

338 CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA

Genus Nostoceras Hyatt.
Nostocevas hyatti Siseasncon.
Nostoceras cf. keynense (Anderson) .
Nostocevas votundum sp. nov.
Nostoceras helicinum (Shumard)
Nostoceras (2?) obtusum sp. nov.

Family DIpPLOMOCERATIDAE Spath.
Genus Polyptychoceras Yabe

Polyptychoceras pseudogaultianum (Woloyania)

Family DESMOCERATIDAE Zittel
Subfamily Puzosinae Spath
Genus Kitchinites Spath.
Kitchinites angolaensis sp. nov.
Subfamily Desmoceratinae Zittel
Genus Desmophyllites Spath . : :
Desmophyllites diphylloides (Forbes)
Subfamily Hauericeratinae Matsumoto
Genus Oiophyllites Spath
Oiophyllites angolaensis Spat
Family PACHYDISCIDAE Spath 3
Genus Eupachydiscus Spath
Eupachydiscus pseudogrossouvrer Collisnen
Family PLACENTICERATIDAE Hyatt
Genus Hoplitoplacenticeras Paulcke .
Hoplitoplacenticeras cf. marrott (Coquand)
Hoplitoplacenticeras cf. costulosum (Schliiter)
Hoplitoplacenticeras spp. indet.
Family SPHENODISCIDAE Hyatt
Genus Manambolites Hourcq .
Manambolites dandensis sp. nov.
Genus Sphenodiscus Meek
Sphenodiscus sp. indet. .
Family NAuTILIDAE d’Orbigny
Genus Eutrephoceras Hyatt
Eutrephoceras simile Spath

IV AGES OF THE FAUNAS DESCRIBED :
(a) Douvilleiceras fauna of Dombe Grande
(b) Neokentroceras fauna of Praia do Jombo
(c) The Egito fauna
(d) The Barra do Dande Payne
(e) The Carimba fauna
(f) The Benguela and San Nicolau Pareiies

VY REFERENCES .

CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA 339

SYNOPSIS

Five separate taunas are described from a collection of over 250 Cretaceous ammonites and
nautiloids from Angola. They are as follows:
(1) 9 Douvilleiceras from Dombe Grande, which fix the age as the Mammillatum Zone, Lower
Albian.
About 50 Neokentroceras from Praia do Jombo, north-east of Lobito, which are the best
specimens yet found of the genus, and are of low Upper Albian age.
(3) 85 ammonites of the genera Anagaudryceras, Gaudryceras, Didymoceras (including D.
subtuberculatum sp. nov.), Polyptychoceras, Kitchinites (K. angolaensis sp. nov.), Desmophyllites,
Oiophyllites, Eupachydiscus, Hoplitoplacenticeras and Tetragonites from Egito, which fix
the age as the Vari Zone, Upper Campanian.
26 ammonites of the genera Neophyllocevas, Baculites, Nostoceras (including N. votundum
and N. (?) obtusum spp. nov.), Polyptychoceras, Manambolites (M. dandensis sp. nov.) and
Sphenodiscus from Barra do Dande, of which the Sphenodiscus is probably Upper
Maastrichtian, while all the remainder are either Polyplocum Zone, Upper Campanian, or
basal Maastrichtian.

The description of Baculites subanceps from Carimba has made necessary a full revision of the
European species B. anceps Lamarck; the type population from Manche, France, is described,
a selection of specimens are figured and a neotype is designated.

—

I INTRODUCTION

TuE bulk of the ammonites described in this paper were collected between 1928 and
1931 by Henrique O’Donnell and Alexandre Borges, both of Servico da Carta
Geologica of Angola (now superseded by the Servicos de Geologia e Minas at Luanda).
O’Donnell sent 221 cephalopods (210 ammonites and 11 nautiloids) to Dr. L. F. Spath
for determination and description in 1930. They are now in the collections of the
British Museum (Natural History) and consist of the following:

81 ammonites from the Upper Albian of Praia do Jombo.
7 ammonites from the Cenomanian of Salinas.
I ammonite and 2 nautiloids from the Senonian of San Nicolau.
7 ammonites (1 now lost) from the Campanian of Carimba.
Io ammonites from the Campanian of Benguela.
85 ammonites and g nautiloids from the Campanian of Egito.
1g ammonites from the Campanian and Maastrichtian of Barra do Dande.

Efforts were made by Spath from September 1930 to October 1935 to reach
agreement with O’Donnell and later with Fernando Mouta on the cost and place of
publication of a full description of this collection, but satisfactory terms could not
be agreed upon. The negotiations with Mouta were reopened in 1950 with the result
that Spath was then able to publish his “Preliminary notice” of the collection in
1951. Spath was never able to start on the full description he had wanted to publish
for so long, and only now, 35 years after the collection first arrived here, is it possible
to present the full description that the ammonites clearly deserve. Previous references
to the collection as a whole were made by Mouta & O’ Donnell (1933: 64) and Mouta
(1938: 33). The 7 Cenomanian ammonites from Salinas were described by Spath
(1931: 316), and they all belong to species described by Douvillé (1931). The Egito

340 CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA

ammonites were also referred to by Spath (1940a@: 52). Finally both the Egito and
Barra do Dande faunas were listed and discussed by Spath (1953: 49-50) in his
paper on the Antarctic Campanian cephalopod fauna, and five of the specimens were
figured: (Spath 1953; pl. 2, fig. 6; pli 3, fig: 6} pl. (6; fie. 6; pls 7, fe 75 plaagaties Ze

Descriptions of the lamellibranchs, gastropods and echinoids collected at the same
time by O’Donnell were also delayed; the lamellibranchs and gastropods were
described by Rennie (1945) and the echinoids by Dartevelle (1952: 27; 1953).

Alexandre Borges was less successful in sending his ammonites to Spath for
description. He had concentrated on collecting examples of Dowvilleiceras from
localities between Benguela and Dombe Grande in 1930 and 1931 and had finally
obtained over 50 specimens. These he attempted to send to Spath in 1931 and again
in 1932, but for some unknown reason the collection never left Angola. Through
the kindness of the Director of the Servicos de Geologia e Minas at Luanda I have
been able to see and describe the 9 specimens which are all that now remain of the
original 50 Douvilleiceras.

Other collections of Angolan ammonites in the British Museum (Natural History)
that are described here are the 7 heteromorph ammonites collected by Mr. Beeby
Thompson at Barra do Dande in about 1915 that were referred to by Spath (1921: 56),
6 examples of Neokentroceras from Catumbella purchased from Dr. W. J. Ansorge in
1905, and the Neokentroceras in Professor Gregory’s collection that were described
by Spath (1922). All these collections, and two smaller ones, also contain many
examples of the well-known Upper Albian ammonites of Angola described by Spath,
Haas and others, but none of them belongs to undescribed species or warrants further
description.

Acknowledgements. Loans of type or figured specimens or of plaster casts of type
specimens were kindly made available by Carlos A. Neves Ferrao, Director of the
Servicos de Geologia e Minas, Luanda, Dr. N. P. Newell, of the American Museum
of Natural History, New York, Dr. L. Cahen, Director of the Musée royal de
l Afrique centrale, Tervuren, Dr. A. W. Crompton, Director of the South African
Museum, Cape Town, and Dr. J. Sornay of the Muséum national d’histoire naturelle,
Paris. Mr. C. W. Wright made some helpful suggestions on the species of Baculites
discussed. The majority of the photographs were taken by the author, but a few of
the larger specimens were taken by Mr. N. Tanti.

Measurements. Whorl dimensions are quoted in millimetres in the following order:
Diameter: whorl height, whorl breadth, width of umbilicus. Figures in brackets
following each of the last three figures express that figure as a proportion of the
diameter.

II AMMONITE FAUNAS OF THE MARINE CRETACEOUS OF ANGOLA

A complete bibliography of Angolan geology can be found in Andrade & Andrade
(1958) and a bibliography of the Jurassic and Cretaceous rocks in Haughton (1959).
General accounts of the Cretaceous of Angola are available in Mouta (1954: 53-58)
and Haughton (1963: 277-283). Cretaceous sediments are confined to the coastal
strip of Angola and stretch from Mogamedes in the south to Cabinda in the north.

CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA 341

Except in the Cuanza basin where the width reaches 140 km., the strip is nowhere
more than a few kilometres wide. Along the whole coastal strip lagoonal and
continental deposits of Aptian or pre-Aptian age rest directly on the basement
complex. Marine conditions first appear towards the top of the Aptian and a thick
series of sediments (attaining 2000 metres in places) was laid down, containing
representatives of all the stages up to the top of the Cretaceous. The marine beds
of this coastal strip can conveniently be divided into five basins (Neto 1961: 63).
Ammonites have not been found in the two northerly basins of Cabinda and Congo,
but occur in considerable numbers in the Cuanza, Benguela and Mocgamedes basins.

(a) Mocdmedes basin. The general succession in this small southerly basin is as
follows (Carvalho 1960: 37-48; 1961: 27-93, 210-212; Haughton 1963: 278-279):
Maastrichtian. Fauna of fish teeth.

Santonian or Campanian.

Basalt.

Cenomanian. Limestone with concretions.

?Albian. White Limestone.

Unfossiliferous sandstone.

Conglomeratic facies of torrential origin.
1. Lagoonal facies.

Lamellibranchs and gastropods are common in divisions 4, 5 and 7 and have been
described by Rennie (1929; 1945), but the ages of the lower two were wrongly stated
to be Senonian. From a single bed only 0-4 metres thick in the upper part of division 5
at Salinas came the fine ammonite fauna described by Douvillé (1931). Spath (1931:
316; 1932a: 124) reviewed the determinations of those ammonites and established
that, contrary to Douvillé’s assertions that Barremian to Turonian forms were
represented, all were Cenomanian in age. A single specimen from Salinas was figured
by Haas (1952: 2-4, figs. 3, 4) as Desmoceras latidorsatum (Michelin), var. inflata
Breistroffer, and referred to the Albian. Its position in the succession at Salinas is
not known. It agrees closely with species of known Albian age in the Benguela basin,
but the species and variety occur in both the Upper Albian and Lower Cenomanian
in other areas, so it may have been part of the Cenomanian fauna at Salinas described
by Douvillé. The only other ammonite known from the succession of this basin is
the specimen from division 7 at San Nicolau recorded as Baculites aff. asper (Morton)
by Spath (1951: 9), which is not specifically determinable and may be Santonian
or Campanian.

(b) Benguela and Cuanza basins. The succession in the Benguela basin has been
described by Neto (1960: 89-99; 1961: 63-93) and Haughton (1963: 279-281), and
stratigraphical descriptions and maps for the Cuanza basin can be found in Brognon
& Verrier (1958: 61-74), Hoppener (1958: 75-82) and Freneix (1959: 111-113). The
succession and ammonite faunas of both basins are similar and may be considered
together.

1. Albian. The celebrated Albian ammonite fauna of Angola is known mainly
from localities close to Benguela. Important early works on the stratigraphy and
ammonites of the Albian of that region by Choffat (1888; 1905) and Gregory (1910;

Cee Ga SN eo

342 CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA

1922) were summarized and expanded by Spath (1922) when he described an extensive
collection made by Professor Gregory. Further Albian collections were described by
Haughton (1925), Airachi (1931), Thiele (1933) and Haas (1941). The whole of the
previous work was again summarized by Haas (1942) when he described a large
collection from the Albian of Hanha. Further Albian ammonites have been described
by Haas (1945; 1952—but some are Campanian and are listed below), Sornay
(1951; 1953) and Soares (1959). Almost the whole of this Albian fauna is of Upper
Albian age. It is rich in specimens of Hysteroceras, Neokentroceras, Mortoniceras,
Elobiceras, Puzosia and Hamitidae, of which the lowest in the succession are
Hysteroceras and Neokentroceras (see p. 400 below) and date the base of the series as
low in the Upper Albian. Specimens of Stoliczkaia figured by Choffat (1888: 69, pl. 2,
figs. 5-9) and recorded by Haughton (1925: 270) and Mouta & O’Donnell (1933: 63)
(none were seen by Spath or Haas) occur in beds above the main Mortoniceras
bearing beds, and led to the proposal (Mouta & O’Donnell 1933: 58-63; Mouta
1954: 128) of a formation characterized by Stoliczkaia. This is still Upper Albian in
age, probably the upper half. (A Stoliczkaza figured by Douvillé (1931: 29, pl. 2, fig. 2)
from the Salinas fauna is almost certainly Cenomanian, like the remainder of
Douvillé’s ammonites). Beds below the Upper Albian succession contain specimens
of Douvilleiceras and Puzosia in some abundance (Neto 1960: 96; 1961: 69),
indicating a Lower Albian age, but only one of the examples of Dowvilleiceras has
ever been figured (Choffat 1888: 71, pl. 3, fig. 1). In the collections with which the
present paper is concerned there are examples of most of the Upper Albian genera,
but nothing new, except in the case of Neokentroceras, which is represented by a
splendid series of specimens that are described in detail below and greatly extend
our knowledge of this genus. A small collection of Dowvilleiceras is also described,
which establishes the age of the beds from which they come as Lower Albian.

2. Cenomaman—Santoman. All the stages of the Upper Cretaceous are probably
present in the Cuanza basin (Brognon & Verrier 1958) and ammonites from most of
them have been mentioned by Hoppener (1958: 79-81). A Cenomanian Acanthoceras
and a Turonian Mammutes were recorded by Thiele (1933), and Haas (1942a) described
two poorly preserved ammonites, ?Mantelliceras and Sharpeiceras goliath, that are
probably Cenomanian, a poor Turonian ?Romaniceras, and three well preserved
Texanites of Santonian age. An Upper Santonian Placenticeras, P. reineckei, was
figured by Haughton (1925: 271, pl. 13, figs. 4, 5). More recently Basse (1963:
871-875, pls. 22-24) has described a new collection of Upper Turonian—Lower
Coniacian ammonites from Cape Ledo, Cuanza basin, which consists of examples
of Prionocyclus and Subprionocyclus, and the new genus Ledoceras. Nothing
comparable with the excellent Cenomanian ammonites of the Mocamedes basin has
been found in the Benguela or Cuanza basins.

3. Campanian and Maastrichtian. The presence of ammonites of these two stages
has often been mentioned, but only a few have been described hitherto. Their first
mention was by Spath (1921: 56), referring to the Barra do Dande Nostoceras
collected by Beeby Thompson that are described herein. The first to be described
and figured were Haughton’s (1925) Campanian and Maastrichtian ammonites from

CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA 343

Carimba, consisting of species of Nostoceras, ?Didymoceras, ?Solenoceras, Baculites,
Menuites and Libycoceras. Further ammonites from the Carimba district and from
Capolo were described by Haas (1943), all consisting in this case of the heteromorphs
Nostoceras, Axonoceras, Solenoceras, and Baculites. Preliminary identifications of the
Campanian and Maastrichtian ammonites described herein were given by Spath
(1951; 1953: 49, 50). Two fine specimens of Nostoceras from Barra do Dande were
figured by Sornay (1951), and a fragment of a large Didymoceras from the same
locality was figured by Silva (1961). All the above ammonites are from the Cuanza
basin, but a Campanian succession also occurs in the Benguela basin, especially at
Egito. Part of the Egito Campanian ammonite fauna was described unwittingly by
Haas (1952) and wrongly referred to the Albian. Haas (1952: 16) said “‘the Albian
age of the Ammonoidea here described is beyond any doubt’, but at Egito, Campanian
beds he unconformably on Upper Albian, and ammonites from the Egito Campanian
were mixed in his descriptions with Albian ammonites from other localities.
“Puzosia lytoceroides” Haas (1952: 8-11, figs. 14-17) is the Upper Campanian form
Gaudryceras varagurense (Kossmat), “Gaudryceras aenigma’ Haas (1952: II-12,
figs. 18-20) is Anagaudryceras mikobokense Collignon, and the smaller of the two
specimens figured as Tetragonites jurinianus angolana Haas (1952: 12-15, figs. 21,
23-25 only) is probably Campanian and is best identified as Tetragonites cf. epigonus
(Kossmat). The other ammonites described by Haas are all from Albian localities
in the Benguela region, the only doubtful ones being the four Egito specimens listed
as Desmoceras latidorsatum (Michelin) var. inflata Breistroffer (Haas 1952: 3, 4),
none of which was figured. Measurements of these four given by Haas agree with
those of the Albian Catumbela specimens, and it is doubtful whether anything in
the Campanian has such thick and depressed whorls, so their reference to the Albian
species is probably correct.

The rich Campanian and Maastrichtian collections from Egito and Barra do Dande
that were summarized by Spath (1951) are described below, and there are smaller
faunas from the Senonian of Carimba, Benguela and San Nicolau. The collection
is richer than any Upper Cretaceous ammonites previously described from Angola.

IT SYSLEMALLO DESCRIPTIONS

Family DOUVILLEICERATIDAE Parona & Bonarelli 1879
Genus DOUVILLEICERAS Grossouvre 1894

Douvilleiceras mammillatum (Schlotheim) ? var. aequinodum (Quenstedt)
Plate I, figs. 1-4

1846 Ammonites monile aequinodus Quenstedt: 138, pl. Io, fig. 2.

1888 Acanthoceras mamuillarve (Schlotheim); Choffat: 71, pl. 3, fig. 1.

1925 Douvilleiceras monile (J. Sowerby); Spath: 73, pl. 5, fig. 5.

1962 Douwvilleiceras mammillatum (Schlotheim) var. aequinodum (Quenstedt); Casey: 271,
pl. 40, fig. 5, pl. 41, figs. 5-7, pl. 42, fig. ro.

344 CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA

MATERIAL. 8&8 specimens, D.G. 294, 300, 306-309, 312 and 322, from Dombe
Grande, Benguela basin, in the collection of the Servicos de Geologia e Minas,
Luanda.

Description. The collection consists of four complete specimens, the largest
being 63 mm. diameter, and four fragments of less than half a whorl. The whorl
section is depressed in all specimens, with a height/breadth ratio of 0-75 to 0-80.
There are 28 to 30 ribs per whorl at 60 mm. diameter. Up to about 40 mm. diameter
all the ribs appear to commence at the umbilical edge, but at larger diameters about
one-third are intercalated and commence only very weakly at the umbilical edge or
in the middle of the side of the whorl. The ribs on all whorls are inclined slightly
backwards. Each rib bears seven tubercles on each side of the whorl, which are
equal in size and approximately evenly spaced after 45 mm. diameter. The largest
specimen has an eighth tubercle on ribs near its aperture. At sizes smaller than
45 mm. diameter a much larger single lateral tubercle occurs on alternate ribs. These
ribs have a small umbilical tubercle, the large lateral tubercle and three small
ventro-lateral tubercles, and the ribs with which they alternate bear 5 or 6 small
tubercles. At sizes smaller than 25 mm. diameter the large lateral tubercle appears
to be developed on every rib. The mid-ventral sulcus is only a slight depression in
the ribs which are continuous across the venter; it is roughly equal to the distance
between the first and third ventro-lateral tubercles. Only poor traces of septa and
suture-lines are to be seen in the specimens, but the three largest complete examples
appear to have about two-thirds of a whorl of body chamber each, and are presumably
immature.

Measurements of the four best examples are as follows:
D.G. 294. —————: 24:0, 29°9, ——.
D.G. 306. At58mm.: 24:1 (0°42), 29:2 (0°50), 20-6 (0°36).
D.G. 308. At 58-6 mm.: 24:0 (0:41), 29°7 (0:51), 19:0 (0°32).
D.G. 309. At 55:2 mm.: 22-6 (0-41), 28-2 (0-51), 18-3 (0°33).

Remarks. The full synonymy of Douvilleiceras mammuillatum (Schlotheim) and
its varieties has been given by Casey (1962: 265-274). The present Angolan specimens
are referred to var. aequinodum of that species rather than to the type variety because
of the fairly high rib density of 28 to 30 ribs at 60 mm. diameter. The development
of a large lateral tubercle up to 45 mm. diameter and the relatively wide ventral
sulcus are more like the type variety of the species, while the umbilical width could
be that of either variety when compared with Casey’s (1962: 267, 271) measurements.
The strength of the ribs is variable in the Angolan specimens due to the varying
preservation, but in some places the ribs are as strong and wide as in typical English
and French examples of the species.

The only previously figured Angolan Dowvilleiceras (Choffat 1888: 71, pl. 3, fig. 1)
shows exactly the same characters as the present collection and is here referred to
the same species and variety. It has the large lateral tubercles on the inner whorls
and is drawn with eight tubercles on each rib near its aperture at about 70 mm.
diameter.

CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA 345

In Britain and France this species is confined to and characterizes the Mammillatum
Zone, the upper half of the Lower Albian. The species also occurs in Madagascar
(e.g. Besairie 1936: 158, fig. 10d; Collignon 1949: 76; 1950: 46; 1963: figs. ?1238,
21239, 1241, ?1242, ?1248) where its stratigraphical position, characterizing a zone
at the top of the Lower Albian, is again accurately known (Besairie & Collignon
1956: 32-36; 1960: 68-74). The only other record from Africa is of specimens from
Somalia recorded and figured by Tavani (1942: 33, pl. 3, fig. 10; 1949: 37).

Douvilleiceras orbignyi Hyatt
Blatesmé fies .5

1841 Ammonites mammuillaris Schlotheim; d’Orbigny: 249, pl. 73, figs. 1-3.

1903 Douvilleiceras orbignyi Hyatt: 110.

1923 Douvilleicevas mammuillatum (Schlotheim) var. baylei Spath: 70, pl. 5, fig. 4.
1962 Douvilleiceras orbignyi Hyatt; Casey: 279, pl. 40, figs. 6-8, pl. 42, figs. 12, 13.

MATERIAL. One specimen, D.G. 305, from Dombe Grande, Benguela basin, in
the collection of the Servicos de Geologia e Minas, Luanda.

DEscripTIon. The specimen consists of a half whorl fragment of about 50 mim.
maximum diameter. The whorl section is greatly depressed, the whorl height and
breadth being 17:5 and 25-6 mm. respectively near the aperture. Very large ventro-
lateral tubercles, each divided by three spiral ridges, define a deep U-shaped
mid-ventral sulcus. Large spinose mid-lateral tubercles occur on alternate ribs and
below these there are tiny umbilical tubercles. Just before the broken aperture there
is a single low rib with small tubercles; otherwise the ribbing is very weak throughout.

REMARKS. This single specimen agrees with typical English and French examples
of D. orbignyi at similar sizes. It is readily distinguished from any of the varieties of
D. mammuillatum by the large ventro-lateral tubercles. D. orbignyi has these tubercles
without, or with very few, intermediate small ribs. D. alternans Casey differs in
having one intermediate rib at 50 to 100 mm. diameter, and D. magnodosum Casey
and D. imaequinodum (Quenstedt) both have two intermediate ribs at similar sizes.
These characters appear to be constant in these species, although there is considerable
variation in other details of the ornament. In D. orbignyi the size of the lateral and
ventro-lateral tubercles and the size of the ribs show much variation amongst the
French neotype and topotypes and English specimens figured by Casey (1962: 279,
figs. 99, 100, pl. 40, figs. 6-8, pl. 42, figs. 12, 13). The Angolan specimen has weak
ribs more like the neotype than some of the other figured examples. The Madagascan
species D. benonae Besairie (1936: 164, pl. 15, figs. 15, 16; Collignon 1963, fig. 1244)
has even larger ventro-lateral tubercles and many more intermediate ribs.

In Britain and France D. orbignyi is an associate of D. mammullatum in the
Mammillatum Zone. Several specimens are known from Madagascar from the same
zone at the top of the Lower Albian (Besairie 1936: 160; Collignon 1949: 76; 1950:
46; 1963: figs. ?1240, 1248).

346 CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA
Family BRANCOCERATIDAE Spath 1933
Subfamily BRANCOCERATINAE Spath 1933
Genus NEOKENTROCERAS Spath 1921

TYPE SPECIES. Neokentroceras curvicornu Spath 1921.

EMENDED DIAGNOSIS. Small size; largest known adult is 40 mm. diameter when
complete. Evolute, whorl section quadrilateral or rounded-quadrilateral. Ribs
weak or absent in most species, but moderately strong in some. Umbilical tubercle
strong; lateral tubercle weak or absent; ventro-lateral tubercle strong, clavate or
spiny, but is sometimes absent when ribbing is strong. Keel present in all species.
On final part of the adult body chamber the ventro-lateral tubercles become replaced
by high ribs which curve strongly forwards to form continuous folds across the venter,
and the keel is almost completely lost.

AGE AND DISTRIBUTION. Lower half of the Upper Albian. Angola, ? Nigeria,
? Brazil.

Remarks. The first proposal of Neokentroceras (Spath 1921a: 306) consisted
merely of four words of description and the designation of a type species which was
a nomen nudum. In a paper the following year Spath (1922: 105-107, 139-143,
text-fig. D) gave full descriptions and discussion of the genus, its type species, and
three further new species. Only 21 specimens were available to Spath; of these,
6 were not described (these are N. trituberculatum sp. nov. described below), and
only 4 out of the remaining 15 were reasonably complete specimens. Spath’s poor
illustrations made interpretation of the genus and its species very difficult for later
workers except by reference to his original specimens.

A second collection of Neokentroceras from Angola was described at length by
Haas (1942: 46-66, pls. 7-10). It consisted of 117 specimens, of which all except
about 9 were fragments of less than half a whorl. Haas adopted the 4 species and
I variety of Spath and proposed a further 4 species and 4 varieties.

The only other discussion of this genus is Reyment’s (1955: 39-41) description of
three Nigerian specimens, which were referred to the type species of the genus, but
two of them were made the type specimens of a newly created subspecies.

The present collection yields a considerable amount of new information on
Neokentroceras, for, although there are only 48 additional specimens, 33 of them are
fairly complete and 20 have adult body chambers or adult suture-lines preserved.
All are from a single locality at Praia do Jombo, Benguela basin, Angola. There are
several specimens in each of the species described below which are complete up to
the adult mouth border, and they all show a similar type of modification of the
ornament on the final part of the body chamber. The ribs on the side of the whorl
strengthen in all cases; where ventro-lateral tubercles are present they diminish in
size and lose much of their tuberculate nature to become merely raised portions of
the ribs; the ribs form chevrons or folds that are continuous across the venter, and
the keel diminishes markedly, almost disappearing in many cases. In all instances

CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA 347

where the final suture-lines and the modified ornament on the body chamber are
seen in the same specimen, the final suture-lines are approximated.

The most highly developed species of Neokentroceras is the heavily tuberculate
type species, NV. curvicornu, which has characters that are clearly different from any
other genus of comparable age. The two ribbed species N. pseudovaricosum Spath
and N. crassicostatum sp. nov., are, on the other hand, not far removed from some
species of Hysteroceras. Amongst the Angolan forms Hysteroceras varicosum
(J. Sowerby) var. angolana Haas (1942: 21-24, pl. I, fig. 21, pl. 2, figs. I-17) bears
considerable resemblance to the ribbed species of Neokentroceras. Small inner whorls
of N. pseudovaricosum and H. varicosum var. angolana are so alike as to be virtually
indistinguishable, and it is probable that the two species are closely related.
Hysteroceras orbignyi (Spath), a well-known species of the English Gault which is
also found in Angola, is related to ribbed species of Neokentroceras. In all species of
Hysteroceras the keel rapidly disappears and the ribs are continuous across the
venter on most or all of the body chamber, whereas in Neokentroceras this stage is
only reached on a short portion of the adult body chamber just before the mouth
border.

In view of the characters of the adult Neokentroceras that are now known, the two
Nigerian specimens figured as the new subspecies N. curvicornu crassicornutum by
Reyment (1955: 41, pl. 4, figs. 7, 8) cannot be placed in this genus. The smaller
specimen (pl. 4, fig. 8) has large swollen ventro-lateral tubercles, small lateral
tubercles and umbilical tubercles, while the larger specimen (pl. 4, fig. 7) shows a
larger body chamber (? adult) with a broad flat venter and a strong keel, and
quadrituberculate main ribs and some trituberculate intercalated ribs that do not
reach the umbilical edge. These are clearly characters of the subgenus Mortoniceras
(Durnovarites) to which both Reyment’s specimens should be referred, as MM. (D.)
crassicornutum, a species with particularly large ventro-lateral tubercles on the
inner whorls. Reyment’s third specimen (1955: 41, pl. 4, figs. 9, 9a), from a slightly
lower horizon and preserved in a different matrix, is a fragment of a whorl which
may well be a genuine N. curvicornu. From the body chamber characters of the
largest specimen referred to above, Reyment (1955: 39) deduced that Neokentroceras
was related to the quadrituberculate forms of Mortoniceras, a relationship first
suggested by Spath (1922: 106). This is not correct for the proper adult characters
now known for Neokentroceras point strongly to this genus being a late end-form
development from Hysteroceras, a view adopted later by Spath (1934: 472-473) and
also by Haas (1942: 47-48). Its age is therefore low in the Upper Albian. Neokentro-
ceras should be referred to the subfamily Brancoceratinae rather than to the
Mortoniceratinae, for it is unlikely to have had any direct connections with members
of the latter family.

Records of Neokentroceras indicating a world-wide distribution were listed by
Spath (1922: 105-107) and by Haas (1942: 46-47). Spath’s (1934: 472) later view,
that the genus was restricted to Angola, seems to be more correct, for records of the
genus from Texas, Tunisia, India and Borneo are all based on figured specimens
which are examples of Mortoniceras (s.1.), Spathiceras or Dipoloceras. The single

348 CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA

specimen from Nigeria figured by Reyment (1955: pl. 4, figs. 9, 9a) appears to be a
genuine Neokentroceras, and the record of N. tectorius (White 1887: 225, pl. 20,
figs. 6, 7) from Brazil, based on a diagrammatic drawing of a single specimen, is
doubtful. Thirteen specimens from the Upper Albian of Madagascar figured by
Besairie (1931: 633, pl. 65, figs. 4~7) and Collignon (1932: 16-17, pl. 3, figs. 1-9)
are close to Neokentroceras. However they are all inner whorls of less than 15 mm.
diameter, ribs are present in all cases together with small umbilical and ventro-lateral
tubercles, and on the venters of even the most tuberculate specimens the keel is
always dominant over the ventro-lateral tubercles. Their reference to Hysteroceras
is more logical, for several of them are close to the more tuberculate examples of
H. orbignyt Spath and H. binum (J. Sowerby) from the English Gault. Thus apart
from possible occurrences in Nigeria and Brazil, there do not appear to be any
records of genuine Neokentroceras from outside Angola.

The present division of Neokentroceras into species is unsatisfactory, owing to the
poor illustrations in Spath’s (1922) original paper, and to the fragmentary nature
of nearly all the specimens described by Haas (1942). The collection described here
contains the first complete specimens to be found. Haas’s division into 8 species and
5 varieties 1s excessive for many of his forms can be seen to represent individual
variation within a species amongst the present collection. The amount of variation
within one species is well illustrated in the 7 specimens of N. pseudovaricosum
described and figured below (PI. 3, figs. 5-11). They show variation in adult size
giving a factor of nearly 2:1 between the largest and smallest, and marked variation
in rib density and whorl thickness. There are four or five different combinations of
adult size, rib density and whorl thickness, yet all are united by the possession of
highly characteristic ribs, which are broad and flattened at the ventro-lateral edge.
It is clearly more correct to unite these under one specific name than to divide them
into 4 or 5 species. Similar amounts of variation are found amongst the 29 specimens
of N. curvicornu, and the smaller numbers of other species. In the collection as a
whole divisions can be made at natural breaks in the variation, except in one case
where two species seem to be very close, and the result is that only four of the
previously described species are recognized and two new species are described.

Neokentroceras curvicornu Spath
Plate 2, figs. 1-9

1921a Neokentroceras curvicornu Spath: 306 (nomen nudum).

1922 Neokentroceras curvicornu Spath: 139-140, figs. D 1, Ia, 2.

1942 Neokentrocevas speciosum Haas: 61-63, figs. 6n, o, pl. 8, figs. 14-17, pl. 9, fig. ro.
1942 Neokentroceras speciosum var. vudis Haas: 63, fig. 6p, pl. 8, figs. 18, 19.
?1955 Neokentroceras curvicornu curvicornu Spath; Reyment: 41, pl. 4, figs. 9, 9a.

Horotyes, “C) 20116 (Plpz, nee a):

MATERIAL. In addition to the holotype, 28 specimens, including four paratypes
(C. 20117-18, C. 20123, C. 20289) from the shore at landing place near Hanha,

CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA 349

and C. 52551-54, C. 52556-73, C. 52575 and C 52584 from Praia do Jombo.
Dimensions of holotype: at 24 mm.: 7:7 (0:32), , 10:0 (0:41). Dimensions of
C. 52552: at 26-5 mm.: 9-0 (0-34), 8-3 (0°31), 11-6 (0°44).

Diacnosis. Evolute, whorl section quadrilateral, thickness and height of whorl
approximately equal. Umbilical tubercle large and radially elongated. Ventro-
lateral tubercle very large and forms outwardly pointing spine, sometimes curved
slightly backwards. Keel well formed but lower than tubercles in all cases. Ribs
weak or absent, except on final part of body chamber where tubercles diminish
markedly in size, the keel disappears and the ribs are projected on the venter to
form large folds. Length of adult body chamber about five-eighths of a whorl.

REMARKS. The holotype was badly figured by Spath, but the specimen is poorly
preserved and from the figure given here (PI. 2, fig. 1) it can be seen that the specific
characters are barely discernible. However, the collection contains 24 specimens in
addition to those seen by Spath, and as many of these are well preserved and show
all stages of growth, the species can now be adequately described.

Ten specimens have recognizable adult features, and these have mouth borders at
sizes ranging from 21 to 35 mm. diameter, and approximated last suture-lines at
diameters between 14°5 and 20-5 mm. Modification of the ornament on the adult
body chamber consists of a tendency for the last three pairs of ventro-lateral tubercles
to become elongated and to join across the venter as high forwardly curving ribs,
and at this stage the keel almost disappears. On the middle one-third of the length
of the adult body chamber the ventro-lateral tubercles become elongated into very
large and widely spaced spines, but there is considerable variation in the degree of
coarseness attained and in the direction of the spines, some of which are straight
while others curve backwards even in the same specimen.

The tubercles on the first one-third of the body chamber and the preceding
septate whorls are fairly constant in size and density. At diameters between 20 and
28 mm. the numbers of ventro-lateral and umbilical tubercles average 15 and 10 per
whorl respectively, and only on occasional specimens do these figures rise as high as
18 and 12. On the holotype there are 13 ventro-lateral and 10 umbilical tubercles
per whorl at 27-3 mm. diameter, and the low figure of 13 reflects the wide spacing
of the ventro-lateral tubercles on the last quarter whorl. It is probable that this part
of the holotype is the middle one-third of the length of the body chamber, but this
cannot be confirmed by the suture-lines which are not preserved. Lateral tubercles
are not found at any stage of growth.

Rib development is weak. The umbilical and ventro-lateral tubercles are some-
times joined by a rib at the beginning and end of the body chamber, but these always
show loss of relief when crossing the side of the whorl, and on other parts of the
whorls ribs are absent or only very weak. The keel is small and is always lower than
the ventro-lateral tubercles.

This is the most evolute and most strongly tuberculate species of Neokentroceras,
in which the development of keel and ribs is always very weak in comparison with
the tubercles. N. singulare Haas is closely related and is discussed in detail below.

350 CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA

N. trituberculatum sp. nov. is also similar but develops a lateral tubercle from an
early growth stage.

N. speciosum and its variety rudis described and figured by Haas (1942) are
synonyms of JN. curvicornu. His specimens all fall well within the range of variation
of the latter species. The holotype of N. speciosum (Haas 1942, pl. 8, fig. 14) is close
to the adult growth stage, and compares well with the specimen figured in Pl. 2,
fig. 7. The type specimen of var. rudis (Haas 1942: pl. 8, fig. 18) can also be matched
amongst the present collection (it is fairly close to Pl. 2, fig. 3), and the varietal name
is not worth retaining. The three specimens figured by Haas (1942, pl. 8, figs 20-22)
as N. curvicornu? are small fragments which are not really specifically determinable.

Three Nigerian specimens were figured by Reyment under this specific name.
One of them (Reyment, 1955: pl. 4, figs. 9, 9a) compares well with the specimen
figured here in Pl. 2, fig. 9, and although fragmentary and poorly preserved it is
probably a genuine N. curvicornu. The other two specimens (Reyment, 1955:
pl. 4, fig. 7, 8) were made the types of the new subspecies N. curvicornu crassicornu-
tum: this has been discussed above (p. 347) and shown to be probably a valid species
of Mortoniceras (Durnovarites).

Neokentroceras singulare Haas
Plate 2, figs. 10-15

1942 Neokentroceras singulave Haas: 64-66, fig. 67, s, pl. 9, fig. 11, pl. Io, fig. I.

MATERIAL. 14 specimens, C. 52555, C. 52574, C.52576-83, C.52585-87 and
C. 52597 all from Praia do Jombo.

DiaGnosis. Close to N. curvicornu, but distinguished by being slightly more
involute, with flat and smooth whorl sides, and more compressed whorl shape.
Umbilical tubercles of moderate size; ventro-lateral tubercles large and elongated
into spines curving backwards. Ribs weak throughout. Adult body chamber similar
to N. curvicornu.

Remarks. If a much larger collection were available, a complete gradation
might be found between this species and N. curvicornu, and singulare would then
be considered a variety of the latter species. There are sufficient distinguishing
features in the present collection of only 14 specimens, however, to justify their
separation from N. curvicornu as a distinct, but very closely related species. At all
stages the whorls are more compressed and a little more involute than in N.
curvicornu. The sides of the whorl are nearly smooth in most individuals, and the
tubercles are somewhat smaller than in the latter species.

In the seven specimens that show adult characters, the diameter at the mouth
border ranges from 23 to 35 mm., and the diameter at the final approximated
suture-lines ranges from 15:5 to 22 mm. The body chamber occupies five-eighths
of a whorl and has modifications of the ornament similar to those in NV. curvicornu,
i.e. the ventro-lateral tubercles are large and widely spaced on the middle part of

CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA 351

the body chamber, and just before the mouth border the last 3 or 4 tubercles are
modified to form raised ribs which curve forwards and cross the venter as folds (PI. 2,
mess. IL; 15).

On the septate whorls and the beginning of the body chamber the sides of the
whorls are flat and almost smooth and neither the umbilical nor the ventro-lateral
tubercles project markedly outwards from the side of the whorl as in N. curvicornu.
Ribbing is very weak on these whorls and only occasionally do low ribs join the
umbilical and ventro-lateral tubercles. On whorls between 20 and 25 mm. diameter
there are 10-12 umbilical and 15-18 ventro-lateral tubercles per whorl, but the
number of the latter may fall to 13 if the middle part of the adult body chamber is
included. Lateral tubercles are never developed. The keel is about as high as the
ventro-lateral tubercles on the septate whorls, but diminishes on the body chamber
and disappears just before the mouth border.

The single specimen and holotype of the species described by Haas (1942, pl. Io,
fig. 1) appears to be an almost complete adult, for it has ribs just before the aperture
which cross the venter as folds. The mouth border is just missing and the maximum
size when complete would have been about 25 mm. diameter. It is very closely
matched by the complete adult figured here in Pl. 2, fig. 15.

Neokentroceras subtuberculatum Spath
Plate 3, fig. 1

1888 Schloenbachia lenzi Szajnocha; Choffat: 64, pl. 1, fig. 3 (non figs. 4-6).

1922 Neokentroceras subtuberculatum Spath: 141-142, figs. D 8, 8a.

1922 Neokentroceras choffati Spath: 106.

?1942 Neokentroceras choffati Spath; Haas: 49-51, fig. 6a, pl. 7, figs. 15-18, pl. 9, fig. 4.

1942 Neokentroceras choffati Spath var. crassinoda Haas: 50, pl. 7, fig. 19.

1942 Neokentroceras costatum Haas: 52-53, figs. 6b-d, pl. 7, figs. 20-25, pl. 9, fig. 5.

1942 Neokentrocervas magnum Haas: 53-56, fig. 6g, pl. 8, figs. 2-6, pl. 9, fig. 6.

1942 Neokentroceras cf. subtuberculatum Spath; Haas: 56-58, figs. 6h, 2, pl. 8, fig. 7, pl. 9, fig. 7.

HoLotyre. C. 20042 (Pl. 3, fig. 1), the only specimen, from near Benguela.

REMARKS. The species is poorly known, but the two diagnostic features appear
to be the development of ribs throughout growth and a small lateral tubercle on the
adult body chamber, in addition to small umbilical tubercles and moderate sized
ventro-lateral tubercles.

The holotype was so badly figured by Spath that the species could not be properly
interpreted from his descriptions. The specimen is, in any case, poorly preserved,
and a full description of the species will only be possible when complete, well-
preserved specimens are found. A second specimen, C. 20061, which was referred
to this species by Spath is very badly preserved and is specifically indeterminate.

The only part of the holotype that is at all well preserved is the final half whorl.
This is probably part of the adult body chamber, though it is not possible to prove
this as no suture-lines are preserved and the mouth border is missing. On this part
of the specimen the whorl shape is quadrangular, slightly higher than broad, and has

352 CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA

parallel, almost flat sides. The umbilical tubercles are small and radially elongated,
while the ventro-lateral tubercles are of medium size and point outwards, and have a
tendency to be clavate. Small lateral tubercles are connected to both the inner and
outer tubercles by low ribs. In some cases the radial elongation of the umbilical
tubercle is angled slightly forwards on the ventral side of the tubercle, and the rib
commences from the middle of the tubercle and runs behind this elongation. On
other ribs the elongation is part of the rib itself. There are 18 ventro-lateral tubercles
on the final whorl at about 35 mm. diameter; the number of umbilical tubercles is
less than this, but an accurate count cannot be made owing to the poor preservation.

The holotype of N. choffati Spath was figured by Choffat (1888: pl. 1, fig. 3). This
shows all the characters typical of N. subtuberculatum and there can be little doubt
that it isa synonym. The specimens figured as NV. choffati by Haas are all too small
to be referred with certainty to the present species, though this will probably be
possible when the septate whorls of N. subtwberculatum are properly known. The
variety N. choffati var. crassinoda and the two species N. costatum and N. magnum
of Haas are also included in the synonymy of N. subtuberculatum. A collection of
more complete specimens will be necessary to confirm this synonymy, but the
characters of the fragments figured and described under these names agree closely
with those of N. subtuberculatum.

Neokentroceras trituberculatum sp. nov.
Plate 3, figs. 2-4

MATERIAL. In addition to the holotype, five paratypes, C. 14818-21, C. 20284
all from near Catumbella, Benguela, Angola.

Diacnosis. Whorls robust with quadrangular section. A lateral tubercle of
moderate size occurs in addition to a moderate-sized umbilical tubercle and a large
clavate ventro-lateral tubercle. Ribs weak throughout and often absent on septate
whorls. Keel well formed but lower than ventro-lateral tubercles.

REMARKS. The six specimens referred to this species form part of a collection
purchased from Dr. W. J. Ansorge, and they have been referred to by Spath (1922:
140) and Reyment (1955: 39). The specimen C. 36204 referred to by Reyment
(1955: 39) as belonging to a related but different trituberculate species, is only 16 mm.
diameter, and consists of small inner whorls of Mortoniceras (Durnovarites), as was
recognized by Spath (1942: 713).

This species is characterized by a well developed lateral tubercle which is placed
slightly ventral of the middle of the side of the whorl and is developed from an early
stage of growth. The umbilical tubercles are sharp and pointed on the inner whorls,
becoming radially elongated on later whorls, while the ventro-lateral tubercles are
large and tend to become clavate. Weak ribs are developed between the tubercles
on the adult body chamber, but on the septate whorls they are still weaker or absent.

CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA 353

The holotype is septate up to 25 mm. diameter, but owing to the preservation it
cannot be determined whether the final suture-lines are approximated; these are
followed by five-eighths of a whorl of body chamber ending at a maximum diameter
of 37:5 mm. This specimen is not quite complete, but has a small portion of the
umbilical wall part of the mouth border preserved, indicating a diameter of 40 mm.
when complete. The ornament on the side of the whorl shows no significant modifi-
cation towards the end of the body chamber and the venter at this point is poorly
preserved. There are 16 ventro-lateral and 15 umbilical tubercles on the last whorl
at 38 mm. diameter. C. 20284 is a second large specimen having a maximum diameter
of 38 mm., but the preservation is such that no suture-lines can be seen. It has
16 ventro-lateral and 16 umbilical tubercles on its final whorl. Specimens C. 14818-21
are parts of the inner whorls of four individuals; they all have maximum diameters
between 15 and 19 mm. and suture-lines are only preserved in one specimen. The
lateral tubercle first appears at about 14 mm. diameter in these specimens, at which
size the umbilical and ventro-lateral tubercles are well developed.

All other species of Neokentroceras, except N. subtuberculatum, differ in having no
lateral tubercles. N. subtuberculatum differs in having smaller lateral tubercles that
only appear at later growth stages and in having stronger ribs.

Neokentroceras pseudovaricosum Spath
Plate 3, figs. 5-11
1922 Neokentroceras pseudovaricosum Spath: 142, fig. D 4, 5, 5a.
1922 Neokentroceras pseudovaricosum var. compressa Spath: 142, fig. D 6.
1942 Neokentroceras costatum var. tenuis Haas: 53, figs. 6e, f, pl. 7, figs. 26, 27, pl. 8, fig. 1.
HoLotyPe. C. 20125 (Pl. 3, fig. 5), from the shore landing place near Hanha.

MATERIAL. In addition to the holotype, 6 specimens; C. 20120, C. 20122
(paratypes), C. 20124 from the shore at landing place near Hanha, and C. 52590-92
from Praia do Jombo.

Dimensions are as follows:

C2201255 At Z21.0;mmn: 7-0 (033)10:6" (0-31), —
At 18-9 mm.: 6:5 (0°34), 6-0 (0:31), —.
C. 20120. At 15-7 mm.: 6-2 (0°39), 5:6 (0°35), —.
C. 20122. At 21-0 mm.: 7°8 (0°37), 7-0 (0-33), —.
C. 20124. At 18-9 mm.: 6:5 (0:34), 5:8 (0°30), c.7-0 (0°37).

Adult size c.21 mm., 10 ribs per half whorl at 19-7 mm. diameter.
C. 52590. At 27-5 mm.: 9-0 (0°32), 8-0 (0-29), II-9 (0°43).
At 21-0 mm.: 7:4 (0°35), 6°7 (0°32), 8-3 (0°39).
Adult size c.37 mm., 22 ribs per whorl at 18-4 mm. diameter,
23 at 23°7 mm., 23 at 29 mm.

354 CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA

C. 52591. At 18-2 mm.: 6-2 (0°34), 6:0 (0°33), 7:6 (0°42).
Adult size c.20 mm., 23 ribs per whorl at 18-8 mm. diameter.
C. 52592. At 30:4 mm.: 10°7 (0°35), 9:3 (0°30), 12:7 (0:42).
At 18-9 mm.: 7:3 (0°38), 6-6 (0°35), 7:0 (0:37).
Adult size c.37 mm., 26 ribs per whorl at 21 mm. diameter.

Diacnosis. Coiling less evolute than in other species of Neokentroceras. Whorls
compressed with rounded quadrangular section. Ornament consists of small pointed
umbilical tubercles and falcoid ribs which are wide and flattened at the ventro-
lateral angle and swing forwards on the venter. The ribs are roughly associated in
pairs with the umbilical tubercles, but in most cases connections between ribs and
tubercles are very vague. There are no ventro-lateral tubercles. Keel of moderate
size, fading on the last part of the adult body chamber, where the ribs are continuous
across the venter as chevrons.

REMARKS. Spath’s illustrations of the holotype and one of the paratypes of
this species were so poor that Haas (1942: 58-61) was quite unable to interpret
the species correctly. The specimens he figured as typical forms of the species (Haas
1942, figs. 67, k, pl. 8, figs. 8, 9, pl. 9, fig. 8) are small fragments which are difficult
to place, but they have very large tubercles and are probably rather coarsely tuber-
culate specimens of N. curvicornu, while the specimens he figured (Haas 1942,
figs. 61, m, pl. 8, figs. Io-13, pl. 9, fig. 9) as N. pseudovaricosum var. gracilis are
examples of either N. curvicornu or N. singulare. However, his figured specimens of
N. costatum var. tenuis Haas (1942: 53, figs. 6¢, f, pl. 7, fig. 26, 27, pl. 8, fig. 1) appear
to be genuine specimens of N. pseudovaricosum.

The distinguishing character of N. pseudovaricosum is the type of ornament at the
ventro-lateral edge. Commencing indistinctly at small sharp umbilical tubercles,
the ribs rapidly strengthen and are falcoid on the side of the whorl, then they become
broad and flattened at the ventro-lateral edge and curve strongly forwards on the
venter. True tubercles are not formed at the ventro-lateral edge.

The 7 specimens referred to this species are characterized by these distinctive
ribs and are clearly marked off from all other species of Neokentroceras. In other
characters, however, there is wide variation, as can be seen from the dimensions
listed above. C. 20124 and C. 52591 (Pl. 3, figs. 8, 10) are nearly complete adult
specimens with the mouth border only just missing in each case; the diameters when
complete would have been 21 and 20 mm. respectively. C. 52592 (PI. 3, fig. 11) isa
much larger adult with part of the mouth border preserved at 37 mm. diameter,
while C. 52590 (PI. 3, fig. 9) has final approximated suture-lines at 25-5 mm. diameter
followed by a quarter of a whorl of body chamber, indicating a size when complete
of about 37 mm. diameter. Rib density varies between 20 and 26 ribs per whorl
at 18-22 mm. diameter. C. 52590 has 11 umbilical tubercles and 23 ribs at 29 mm.
diameter. Whorl breadth ranges from 30 to 35% of the diameter at 16-21 mm.
diameter. The low whorl breadth of 30% in C. 20124 led Spath to the proposal of
var. compressa for this specimen. It can be seen, however, that the difference in
whorl breadth between this specimen and the holotype of the species at the same

CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA 355

diameter is only 0-2 mm. or 1%, which is a negligible difference and is much less
than the range of variation in the species. Of the three whorl sections figured by
Spath (1922: 141, figs. D4, 5a, 6), his fig. D4 is accurate, fig. D 5a is drawn much too
wide, for in this specimen the whorl breadth is always less than the height, while
fig. D6 is drawn much too compressed, for the whorl breadth should be 5:8 mm.
The earlier part of the whorl in the latter specimen is slightly crushed by compression,
and it was probably this that led Spath to the proposal of the name var. compressa.
It is not advisable to use any varietal names for this species until the full variation is
better known, for it is unlikely to be completely expressed in a collection of only 7
specimens.

The degree of variation of adult size in this species is comparable with that found
in much larger collections of other small species. The modifications of the ribs just
before the mouth border in the smallest and largest adults (C. 52591 and 52592) are
very similar. In both cases the last 3 or 4 ribs lose much of the broadening and
flattening at the ventro-lateral edge and curve strongly forwards on the venter to
join from opposite sides, while the keel almost disappears.

Neokentroceras crassicostatum sp. nov.
Plate 2, fig. 16, Pl. 3, figs. 12-15

1922 Neokentroceras sp., Spath: 143, figs. D 7, 7a.

HoLotyre. C. 52593 (PI. 3, fig. 12) from Praia do Jombo.

MATERIAL. In addition to the holotype, 7 specimens (paratypes); C. 20126
from the shore at landing place near Hanha, and C. 52594—96, C. 52598—600 from
Praia do Jombo.

Dimensions:

C. 52593. At 32 mm.: 9°8 (0-30), 9:4 (0:29), 16-0 (0°50).
22 ribs and 12 umbilical tubercles at 34 mm. diameter.

C. 52600. At 23-6 mm.: 8-3 (0°35), 7°7 (0°32), —.

Diacnosis. Allied to N. pseudovaricosum, but more evolute, has larger and
more widely spaced ribs clearly connected to umbilical tubercles, and small sharp
ventro-lateral tubercles surmounting ribs on inner whorls. Intercalated ribs not
connected with tubercles also occur.

REMARKS. Of the eight specimens referred to this species, five have adult body
chambers. The holotype (PI. 3, fig. 12) has final approximated suture-lines at 26 mm.
diameter followed by three-eighths of a whorl of body chamber and would have been
about 40 mm. diameter at the adult mouth border. C. 52596 (PI. 3, fig. 14) has nearly
half a whorl of body chamber but the final septa are missing; the last 3 or 4 ribs
before the aperture curve forwards on the venter and meet from opposite sides,
indicating near proximity to the adult mouth border which would have occurred at

356 CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA

37 mm. diameter. C. 52599 (Pl. 3, fig. 13) is a much smaller adult, having approxi-
mated suture-lines at 17:5 mm. diameter, half a whorl of body chamber, similar
modification of the last 4 or 5 ribs, and the adult mouth border would have occurred
at about 25 mm. diameter. C. 52598 (PI. 3, fig. 15) consists of one-third of a whorl,
half septate, half body chamber; the final two suture-lines are only slightly approxi-
mated, but the body chamber has the bold widely spaced ribs characteristic of this
part of the adult. C. 52600 (PI. 2, fig. 16) has approximated suture-lines at Ig mm.
diameter and nearly half a whorl of body chamber. The other three specimens are
fragments, and one of them (C. 20126) was described briefly by Spath (1922: 143).

The small ventro-lateral tubercles on the inner whorls are seen well on the holotype
where they occur on the septate whorls up to about 24 mm. diameter. On other
specimens they disappear at a smaller size, probably corresponding to about half a
whorl before the beginning of the adult body chamber. On the holotype there are
22 ribs and 12 umbilical tubercles per whorl at 34 mm. diameter, and C. 52600 has
21 ribs per whorl at 25 mm. diameter.

The ribs in this species are similar in form to those in NV. pseudovaricosum, but they
differ in being stronger and more widely spaced and show distinct connections with
the umbilical tubercles. Occasional ribs are intercalated and commence at about
the middle of the side of the whorl and are not connected with the umbilical tubercles.
Distinct ventro-lateral tubercles on the inner whorls also serve to distinguish this
species from N. pseudovaricosum. The species shows considerable resemblance in
side view to Hysteroceras varicosum var. angolana (Haas 1942, pl. I, fig. 21, pl. 2,
fig. 1). In the latter variety, however, the ribs are bold and continuous across the
venter of the whole of the body chamber, while the keel and small ventro-lateral
tubercles of the septate whorls are lost at about the beginning of the body chamber.
In N. crassicostatum the keel is present on the whole of the body chamber and only
the last 3 or 4 ribs are continuous across the venter in the form of V-shaped chevrons.

Family PHYLLOCERATIDAE Zittel 1884
Genus NEOPHYLLOCERAS Shimizu 1934
Neophylloceras ultimum Spath

1953 Neophylloceras ultimum Spath: 4, 49, pl. 7, fig. 7.

HoLotyPe. C. 41477, the only specimen, from Barra do Dande.

REMARKS. Several comparable species of Neophylloceras have been described
since Spath (1953: 4, pl. 7, figs. 7a, b) named and figured this single Angolan specimen.
Its greatly subdivided and complex suture-line shows through the very thin
transparent shell, but the continuity is not sufficient to allow it to be figured. The
extremely fine and closely spaced striae can be seen clearly on Spath’s figures and
this character serves to distinguish N. wltimum from all other species. In fact 32
striae cross a length of 10 mm. of venter immediately preceding the aperture of this
specimen, and this density is nearly twice that of the nearest comparable species at a

CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA 357

similar size. Such comparable forms are N. vamosum (Meek) which ranges from the
Turonian to the Upper Campanian and probably the Lower Maastrichtian in western
north America and Japan (Matsumoto 1959): 1-5, pl. 1, fig. 1), N. hetonazense
(Matsumoto 19590: 5) in the Campanian and Maastrichtian of western North America,
Japan and Graham Land, N. lambertense Usher (1952: 50, pl. 1, figs. I-3) in the Upper
Campanian and Lower Maastrichtian of British Columbia, and N. neva (Forbes)
from the Campanian or Maastrichtain in southern India (Kossmat 1895: 166, pl. 16,
fig. 2). N. vamosum and N. hetonatense have recently been figured from Upper
Campanian or Lower Maastrichtian beds in Alaska (Jones 1963: 22, pl. 6, pl. 7,
figs. 1-5) and one of the specimens (pl. 6, figs. 2, 4-6) of the former species has
extremely fine striae almost comparable with those of N. ultimum.

The position of the genus Neophylloceras and its relationship with its Lower
Cretaceous ancestor Hypophylloceras have been discussed by Matsumoto (1959a@:
55-58). Other phylloceratid species in the Campanian and Maastrichtain belong
mainly to the genus Epiphylloceras Collignon 1956. The type species, E. surya
(Forbes), occurs in Angola (Haughton 1925: 268, pl. 12, figs. 3-5) and southern
India (Kossmat 1895: 158, pl. 16, fig. 1) and is characterized by bundled ribbing,
one rib of each bundle being usually enlarged. Several other species occur in the
Maastrichtian of Madagascar (Collignon 1956: 24-25).

Family TETRAGONITIDAE Hyatt 1900
Subfamily GAUDRYCERATINAE Spath 1927
Genus ANAGAUDRYCERAS Shimizu 1934

TYPE SPECIES. Ammonites sacya Forbes 1846.

The interpretation and characteristics of this genus have been discussed at length
by Wright & Matsumoto (1954: I1I-113) and Matsumoto (1959: 73; 1959a: 138).
Wiedmann’s (1962: 156-158) relegation of Anagaudryceras to the synonymy of
Gaudryceras is not accepted. The ornament of all but the adult stage of Anagaudry-
ceras is so fine that the shell appears to be smooth, while Gaudryceras is characteris-
tically covered with fine ribs. This difference is sufficient for generic distinction in
keeping with the scale of differences usually adopted for Cretaceous genera (e.g.
by Wright 1957; Matsumoto 1959, 1959a, 19590). The only additional point concern-
ing the morphology of Anagaudryceras which can usefully be made here concerns
the suture-line. Spath determined the species described below as an evolute species of
Pseudophyllites. When one of the suture-lines was etched out, however, it proved
to have quadrifid lateral saddles (basically bifid, with each arm divided again)
and a single large saddle in the internal suture-line. In Pseudop/yllites the lateral
saddles are basically trifid and there are two or more saddles in the internal suture-
line. These differences in the suture-lines enable involute species of Anagaudryceras
to be distinguished from evolute species of Pseudophyllites where there are few or no
other differences.

358 CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA

Species of Anagaudryceras range from the Upper Albian to the Maastrichtian and
have a world-wide distribution: examples have been described from Europe, North
Africa, Angola, Madagascar, India, Japan, Alaska, California, New Zealand and
Antarctica. The wide distribution has led to a multiplicity of specific names, but
none of the faunas contains more than a very few specimens and it is not yet possible
to make an assessment of the variation within a species. The 17 available specific
names are probably far too many (listed in Collignon 1956: 66, 68-70). One of the
main species is A. sacya (Forbes; see Matsumoto 1959: 72) which has broad band-
like ribs on the body chamber and well marked constrictions on earlier whorls. It
ranges from the Upper Albian to the Turonian and possibly higher; A. buddha
(Forbes), A. vevelatum (Stoliczka) and A. limatum (Yabe) are synonyms; Yabe’s
variety obscura is probably a true variety, but larger and more complete specimens
of the New Zealand Campanian species A. subsacya (Marshall) and A. crenatum
(Marshall) are required before it can be determined whether they also are synonyms.
The second main species has only weak constrictions and no band ribs on the body
chamber. In the Maastrichtian this is A. mzkobokense Collignon and A. aureum
(Anderson) is clearly a synonym; in India Cenomanian ammonites of very similar
morphology have the three specific names A. involutum (Stoliczka), A. madraspatanum
(Stoliczka) and A. wtaturense Shimizu, and in Japan A. yamashitar (Yabe) has only
a marginally smaller umbilicus, but is Santonian. This leaves A. politissimum
(Kossmat) from the Turonian to Santonian of India which has a smaller whorl height
and whorl breadth at the same diameter as A. mikobokense and may represent a
different species, and A. swubtililineatwm (Kossmat) from the Campanian or
Maastrichtian of India which is too fragmentary for identification. Both A.
multiplexus (Stoliczka) from the Cenomanian of India and A. coalingense (Anderson)
from the Maastrichtian of California represent an evolute many-whorled species,
with constrictions but no known ribs; much larger collections are needed to determine
whether these are conspecific.

Such a specific classification could be expected to emerge from a comparison of
abundant material of Anagaudryceras if it were available. The collection described
below consists, however, of only 13 specimens, yet this is one of the largest collections
of a single species of the genus found so far.

Anagaudryceras mikobokense Collignon
Plate 4, figs. 1-3; Text-fig. 1
1938 Gaudryceras politissimum Kossmat; Collignon: 92, pl. 7, fig. 2.
1952 Gaudrycevas aenigma Haas: 11, figs. 18-20.
1956 Anagaudryceras mikobokense Collignon: 59, pl. 8, fig. I.

1958 Lytocevas (Gaudryceras) auveum Anderson: 184, pl. 71, fig. 1.
1959a Anagaudryceras mikobokense Collignon; Matsumoto: 139, pl. 38, fig. 1.

MATERIAL. 13 specimens, C. 52636—48, from 1 km. north of Egito, Angola.

Description. The innermost whorls are exposed and evolute, while the degree
of involution increases slightly with increasing size. The whorl height and breadth

CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA 359

are equal at about 34 mm. diameter; at smaller sizes the breadth exceeds the height ;
at larger sizes the height progressively exceeds the breadth, and at 80 mm. diameter
the breadth/height ratio has a range of 0-80 to 0-90. The largest specimen is wholly
septate at its maximum diameter of 85 mm., and none shows any adult characters.
The shell is smooth and unornamented up to about 30 mm. diameter; at larger sizes
there are straight radial growth striae on well preserved parts of the shell, and
irregularly developed low, widely spaced radial ribs which tend to increase in strength
with increase in size. These ribs are inclined forwards at the umbilical margin,
curve slightly backwards on the side of the whorl and become radial in crossing the
venter. There are no constrictions, although where the ribs cross the venter they
often have the appearance of a low flare, of the sort that are sometimes associated
with constrictions. In the suture-line there are four equal-sized folioles terminating
each of the first and second lateral saddles and the first auxiliary saddle, then there
are two smaller auxiliary saddles before the umbilical edge and a single large lateral
saddle in the internal suture-line. There are small upright saddles in the middle of
the first lateral and first auxiliary lobes. At large sizes the suture-lines become
somewhat further subdivided.

Remarks. These are the specimens originally identified as “Pseudophyllites
sp. nov. (a more evolute form than P. indra Forbes sp.)”’ by Spath (1940a@: 52; 1951:
8; 1953: 49). They are now referred to Anagaudryceras rather than to Pseudophyllites
because of their suture-line characters, which, as described above, enable the two
genera to be separated. Two specimens of average characters are figured in Pl. 4,
figs. I, 3, a slightly more involute specimen is figured in Pl. 4, fig. 2, and a complete
suture-line is shown in Text-fig. I.

Fic. 1. Complete suture-line of Anagaudrycevas mikobokense Collignon from venter to
dorsum at whorl height of 28 mm. C. 52646, from Upper Campanian, 1 km. north of
Egito, Angola. x2:6.

Variation among the 13 specimens is not large and is mainly in the whorl propor-
tions. Graphs of whorl height and umbilical width plotted against the diameter show
a range in whorl height of 28-3 mm. to 32 mm. at 70 mm. diameter, and in umbilical
width of 22 mm. to 24 mm. at the same size. Whorl! breadth is more constant, the
greatest variation being less than 2 mm. at any diameter between 40 mm. (15:5 mm.
whorl breadth) and 80 mm. (29-5 mm. whorl breadth). All the specimens have the

360 CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA

very reduced ornament on the outer surface of the shell, and this is even more reduced
on the inner surface.

An example of the present species from Egito was described and figured by Haas
(1952: 11, figs. 18-20) as Gaudryceras aenigma Haas. This specimen is a perfect match
for the one figured here in PI. 4, fig. 3. The true G. aenigma (Haas, 1942: 167, pl. 42,
fig. 3, pl. 44, fig. 2) is an Albian species and has the fine sharp ribs characteristic of
Gaudryceras.

The Angolan specimens compare very closely with the holotype from the Lower
Maastrichtian of Madagascar described by Collignon. That holotype differs only in
the possession of very faint, rare constrictions. The Californian specimens described
by Anderson and by Matsumoto are also very similar to the Angolan specimens and
undoubtedly conspecific. Both Collignon (1956: 59) and Matsumoto (1959a@: 139)
have included the two specimens from the Campanian of Antarctica figured by Kilian
& Reboul (1909: 14, pl. 1, figs. 7, 8) in the synonymy of A. mikobokense. Although
these Antarctic specimens appear to be smooth, one (fig. 7) shows what appears to be
a strongly curved constriction, and both show traces of strongly prorsiradiate fine
ribs. They are probably specimens of Gaudryceras with the ribs worn away, as is
undoubtedly the case in the two further Antarctic specimens figured by Kilan &
Reboul (1909, pl. 1, fig. 6) and Spath (1953: 12, pl. I, fig. 10).

Other specimens of similar morphology to A. mikobokense but of different ages
have already been briefly mentioned above, but in view of the small number of
specimens involved and the difficulties of comparison, further discussion would not
be of value.

Genus GAUDRYCERAS Grossouvre 1894
TYPE SPECIES. Ammonites mitis Hauer 1866.

The characteristics and synonymy of this genus have been discussed by Wright
& Matsumoto (1954: 111-113) and Matsumoto (1959a: 141), who concluded that
subdivision of the genus is not necessary.

The specific nomenclature of Gaudryceras is in an even greater state of confusion
than that of Anagaudryceras discussed above. Species of Gaudryceras have a world-
wide distribution similar to that of Anagaudryceras, and also include examples known
from South-East Africa, British Columbia and South America. About 27 specific
names have been proposed (for lists see Collignon 1956: 67-60), plus G. alamedense
(Smith 1898), G. devallense Anderson 1958, G. filicinctwum (Whiteaves 1876), G.
navarrense Wiedmann 1962, G. sachalinense (Schmidt 1873) and G. vascogoticum
(Wiedmann 1962). The number of known specimens of Gaudryceras is much greater
than in the case of Anagaudryceras, and from the rich faunas in Madagascar and
Japan it should be possible to work out the variation within each species and a good
specific classification. It has been pointed out by Yabe (1903: 14) and Collignon
(1956: 48-49) that at about 100 mm. diameter the whorls of many species become
rapidly more massive, with whorl height and breadth increasing markedly and
umbilical size decreasing markedly. Outer and inner whorls of the same species

CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA 301

often look very different, therefore, and many have been given different specific
names.

Interpretation of the type species, G. mute, is difficult, because the holotype figured
by Hauer (1866: 305, pl. 2, figs. 3, 4) is distorted to an elliptical shape, and the low
whorl breadth may also be due to crushing. Grossouvre (1893: 227, pl. 26, fig. 4,
pl. 27) figured another small specimen and also a much larger specimen which is a
good example of the much more massive appearance of the whorls at large sizes.
This species retains fine ribs up to the largest known sizes, but further study of the
holotype and of a topotype collection is necessary before it can be properly defined.

Gaudryceras varagurense Kossmat
Plate, fe: 5 Pls eties., 1, 2

1895 Lytoceras (Gaudryceras) vavagurense Kossmat: 122, pl. 17, fig. 9, pl. 18, figs. 2a—c.
21909 6Lytoceras (Gaudryceras) vavagurense Kossmat; Kilian & Reboul: 12, pl. 1, fig. 6.
?1929 ©6Lytoceras (Gaudryceras) vavagurense Kossmat; Barrabé: 180, pl. 9, fig. 16.
?1930 Gaudryceras vavagurense Kossmat; Besairie: 569, pl. 21, fig. 4.
1931 Lytoceras (Gaudryceras) vavagurense Kossmat; Basse: 14, pl. 1, figs. 25, 26.
1931 Lytoceras (Gaudryceras) vavagurense Kossmat; Collignon: 11, pl. 1, figs. 5, 6, pl. 8, fig. 2.
1952 Puzosia lytoceroides Haas: 8, figs. 14-17.
1953 Gaudryceras (Neogaudryceras) pictum (Yabe); Spath: 12, pl. r, fig. ro.
1956 Gaudryceras vavagurense Kossmat; Collignon: 56, pl. 5, fig. 6.
1962 Gaudrycevas navarvense Wiedmann: 158, pl. 9, fig. 3.

MATERIAL. II specimens, C. 52649-59, from 1 km. north of Egito, Angola.

DeEscripTIon. The whorls are evolute and the umbilicus shallow. The whorl
section is rounded with greatest breadth at or near the umbilical edge. Whorl height
and breadth are equal at about 40 mm. diameter; at smaller sizes breadth exceeds
height, at larger sizes height exceeds breadth. The ornament consists of fine ribs,
some of which bifurcate on the side of the whorl near the umbilical edge; there are
also single ribs which do not divide, and a few intercalated ribs that do not reach the
umbilical edge. The ribs are inclined strongly forwards on the umbilical walls, bend
slightly backwards on the side of the whorl, then bend forwards again on the venter.
There are 6 to 8 constrictions per whorl which follow the line of the ribs exactly,
and appear as constrictions on the internal cast with a ridge or collar behind, whilst
on the shell they appear as thickened ribs only.

REMARKS. Spath (1951: 8) determined these specimens as “Gaudryceras sp.
(vavagurense, auct, non Kossmat)”’. Haas (1952: 8, figs. 14-17) had two examples
of this species from Egito amongst his collection. He figured one of them and made
it the holotype of a new species, Puzosza lytoceroides, but it is clearly a fine example
of Gaudryceras varvagurense and compares very closely with the specimen figured here
mo Pl. 5, fig. 1.

The largest specimen in the present collection is 85 mm. diameter, and does not
show the massive whorls which the species develops at about 100 mm. diameter.
Measurements of the whorl proportions obtained from 6 specimens were inadequate

362 CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA

for an assessment of the variation of the species, but they were plotted graphically
and could be compared with the proportions of other specimens. The fine ribs con-
tinue up to the aperture of the largest individual, and from a comparison with the
type specimens of species which develop coarser ribbing, it is deduced that the
present collection belongs to a species which retains fine ribbing throughout growth.
Such species with coarse ribs are known especially from Japan (e.g. G. densiplicatum
(Jimbo)) and all of them show the coarse ribbing well before the growth stage
reached by the Angolan specimens. In another more closely related species, or group
of species, the inner whorls are indistinguishable from those of the Angolan specimens,
but at 50 to 70 mm. diameter the ribs, while remaining small, become more widely
spaced. This is known in western north America as G. demanense (Whiteaves)
(Usher 1952: 59, pl. 4, fig. 1), in Japan as G. tenwilivatum (Yabe 1903: 19) and in
Madagascar as G. lauteli Collignon (1956: 57, pl. 7, fig. 1), all of which are either
conspecific or closely related.

For the fine ribbed species to which the Angolan specimens belong the oldest
name is G. varagurense (Kossmat 1895), for the difficulties of interpretation outlined
above make it inadvisable to use G. mute (Hauer 1866) until it can be properly
defined. The holotype from the Santonian of southern India is a broken and incom-
plete specimen, but its ornament seen on several whorls up to 100 mm. diameter,
and its dimensions obtained from a reconstruction of the spiral, compare closely
with those of the Angolan specimens. Other species which are very close to or
conspecific with G. varagurense are: G. analabense Collignon (1956: 54, pl. 6, fig. 3)
and G. beantalyense Collignon (1956: 53, pl. 5, fig. 3) both from the Coniacian of
Madagascar, and G. variocostatum van Hoepen (1921: 7, pl. 2, figs. 10-12) from the
Santonian of Pondoland, which is based on a specimen of only 40 mm. diameter.
G. cinctum Spath (1921: 41; 1922a: 118, pl. 9, fig. 3) from the Santonian of Natal
appears to be more involute, but it is too small for proper comparisons. The Japanese
Santonian to Maastrichtian species G. stviatum (Jimbo 1894: 35, pl. 6, fig. 6) and its
variety G. striatum var. pictum Yabe (1903: 33, pl. 4, fig. 6) are also fine ribbed, but
again the material is too small and poorly known. G. navarrense Wiedmann (1962:
158, pl. 9, fig. 3) from the Campanian of northern Spain appears to be a typical
G. varagurense showing all the normal characters. G. propemite Marshall (1926:
142, pl. 28, figs. 3, 4) from New Zealand and G. delvallense (Anderson 1958: 183,
pl. 41, fig. 4) from California have strongly curved and wiry ribs and probably
represent a different species. Any attempt to sort out the synonymies outlined here
must await the description of the rich Japanese faunas and a re-assessment of the
Madagascan specimens in the light of the results.

Family BACULITIDAE Meek 1876
Genus BACULITES Lamarck 1799

TYPE SPECIES: B. vertebralis Lamarck (1801: 103) by subsequent designation by
Meek (1876: 391).

CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA 363

Baculites vertebralis was introduced by Lamarck without any description, but with
references to figures of Faujas (1799: 141, pl. 21, figs. 2, 3) and Bourguet (1742, pl.
49, figs. 313-316). Although the figures of these two authors showing short smooth
septate fragments are very poor, it can at least be seen that the whorl sections of all
of them are circular or elliptical. In a later work Lamarck (1822: 647) discarded the
specific name vertebralis in favour of B. faujasii which he proposed for the same
species, with a short description now added, a reference to the figure of Faujas only,
and a statement that the type specimen (in his collection) came from the mountain
of Saint-Pierre, near Maastricht (in south Limbourg, Holland). This type specimen
is lost. J. de C. Sowerby (1828; 186, pl. 592, fig. 1) was able to interpret B. “‘faujasi”’
correctly from this description, stating that the venter and dorsum were equally
rounded, the whorl section elliptical and the shell smooth. Topotypes from St.
Pierre, Limbourg, were well figured by Binckhorst (1861: 40, pl. 5d, figs. Ia-h).
This interpretation of B. vertebralis as a smooth species with an elliptical whorl
section and of Maastrichtian age is now well established (e.g. Nowak 1908: 346,
fig. 8a, pl. 14, fig. 8).

The second important early species of Baculites is B. anceps Lamarck, 1822. Its
interpretation will have to be discussed at length because the Angolan specimens are
very close to a form from the Pacific region which has been referred to a subspecies of
B. anceps. The type area for B. anceps is the outcrops of the Calcaire a Baculites,
in Manche, France. B. anceps shows considerable variation, and as B. vertebralis
occurs in the same beds, it is important to establish the identification of the latter
species, so that its clear separation from B. anceps can be demonstrated. The
necessity for designating a type specimen for B. anceps and describing the characters
of the type population has been stressed by Matsumoto (1959a@: 130-136) and
Matsumoto & Obata (1963: 59-63), for until this is done no further progress can be
made in describing similar species from other parts of the world. Application will be
made to the ICZN to have the specimen designated below as neotype officially
recognized.

Baculites anceps Lamarck
Plate 4, fig. 4; Pl. 5, figs. 4, 5; Pl. 6, figs. 1-5; Text-figs. 2, 3, 5-12

1816 Baculites vertebvalis Lamarck; Defrance: supplement p. 60, pl. 22, figs. 1-3 (date of plate
uncertain).

1822 Baculites anceps Lamarck: 648.

1825 Baculites vertebvalis Lamarck; Blainville: 380, pl. 12, figs. 1-3.

1831 Baculites anceps Lamarck; Deshayes: 224, pl. 6, fig. 2.

1837 Baculites anceps Lamarck; Bronn: 732, pl. 33, fig. 6.

1842 Baculites anceps Lamarck; d’Orbigny: 565, pl. 139, figs. 1-7.

1876 Baculites anceps Lamarck; Schliiter: 145, pl. 40, figs. 2, 6.

1888 Baculites anceps Lamarck; Prestwich: pl. 12, fig. 16.

1889 Baculites anceps Lamarck; Griepenkerl: 106, pl. 11, fig. 2.

?1891 Baculites valognensis Bohm: 50, pl. 1, fig. 13.

1908 Baculites anceps Lamarck var. valognensis Bohm; Nowak: 335, figs. 1-4 (p.331), figs.
6, 7, 9, 12 (p.337); pl. 14, figs. 6, 7.

364 CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA

NreotyrPeE. BM(NH) 32573, from the “Calcaire a Baculites’’ of Manche, France,
is here designated as neotype. It was originally part of Mantell’s collection.

Diacnosis. A species of Baculites in which the venter is always sharpened, and
sometimes a keel is differentiated by slight grooves on either side. The dominant
form is smooth at all growth stages and unconstricted, but others occur in which
ribs varying between weak and strong are formed on either body chamber or septate
portion. These ribs are large and arcuate on the dorsal half of the shell, then they
swing well forwards and are reduced almost to striae that are straight up to the keel
where they form slight crenulations in some cases. Fine striae occur between the
main ribs on the external surface of the shell. A minority of specimens have
constrictions, which occur indiscriminantly on smooth or ribbed forms and vary in
strength between weak and well marked.

DESCRIPTION. The type population occurs in the Calcaire a Baculites in Manche,
Normandy. The locality from which most specimens have been obtained is Valognes.
The largest collection is that in the British Museum (Natural History) and consists
of 84 specimens, 47 of them obtained by Sowerby from de Gerville. The following
description is based on this collection, plus two of d’Orbigny’s originals and four
specimens from de Vibrayes’ collection in the Muséum national d’histoire naturelle,
Paris, sent by Dr. J. Sornay, a total of 90 specimens.

The largest specimen is a body chamber fragment with the mouth border missing,
and has a cross section height of 32 mm. and a width of 22 mm. at the broken
aperture. The height of the shell at the final suture-line before the body chamber
varies between 14 and 26 mm., but some of the smaller specimens are probably
immature. Only one specimen (PI. 5, fig. 4) has characters which in a spirally coiled
ammonite would be taken as indicative of an adult: its mouth border is flared and
the final two suture-lines are much closer together than any of the preceding ones;
it is a small specimen compared with many of the others, the shell height at the
mouth border and final suture-line being 16 and 14:5 mm. respectively. Such flared
mouth borders are seen in a number of specimens, and they all have a long rostrum
on the venter and a smaller one on the dorsum, as shown in one of the specimens
figured by d’Orbigny (1842, pl. 139, figs. 3-5). In all specimens the cross section is
sharpened or keeled on the venter, broad and slightly flattened on the dorsum, and
has well rounded sides, so that even though the venter and dorsum are markedly
different the thickest part of the shell is close to the mid-point of the side. Shallow
grooves defining a distinct keel are present in a few specimens.

The ornament shows considerable variation. The two variables are the presence
or absence of ribs and constrictions, and the following table shows the number of
specimens belonging to each of the nine possible combinations in the collection of
gO specimens.

Although there are no clear divisions between the groups, such a grouping
expresses the variation, and shows that 59 of the 90 specimens are smooth, 16 have
weak ribs and 15 strong ribs; in each of these three groups between one-third and
one-quarter of the specimens have constrictions. The largest group, 42 smooth and

CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA 365

unconstricted specimens, accounts for nearly half the collection. The ribs are highly
arcuate and strongly developed just dorsal of the middle of the side; they are inclined
strongly forwards, straight and reduced to striae on the ventral half of the side, and
reach the venter to form slight crenulations on the keel in some cases; they are also
straight on the dorsum over which they pass without interruption, but are inclined
less strongly forwards. The constrictions are similar to the ribs on the dorsal half of
the side, but on the ventral half they at first follow the ribs, then bend slightly
backwards before swinging well forwards again to reach the venter.

CONSTRICTIONS
Absent Weak Strong
Absent 42 4 13 59
n
is Weak iit 3 2 16
og |
Strong II fo) 4 15
64 7 19 | 90

The specimens figured here to show the range of morphology are: the neotype
(Pl. 5, fig. 5) which has a smooth body chamber, very weak ribs on the septate part
and no constrictions; a smooth, unconstricted specimen, showing the final two
suture-lines close together and part of the flared mouth border (PI. 5, fig. 4); a
specimen with ribs of moderate strength (Pl. 6, fig. 1); a fragment with strong ribs
(Pl. 4, fig. 4); two smooth specimens with constrictions (Pl. 6, figs. 2, 5); and two
ribbed specimens with constrictions (Pl. 6, figs. 3, 4).

REMARKS. Matsumoto (1959a: 130, Matsumoto & Obata 1963: 59) has already
stated that the interpretation of Baculites anceps must be stabilized by the designation
of a type specimen, and has suggested (quoting Wright 7m litt.) that such an
interpretation should be based on d’Orbigny’s (1842) figures of the species. An
examination of the original description and the type population of the species leads
to somewhat different conclusions.

Lamarck (1822: 648) described the species as follows:

“Baculite gladiée. Baculites anceps.

B. testa recta, compressiuscula, ancipiti, laevi; uno latere subacuto, altero
crassiore, obtuso; siphone marginale ad latus acutum. Habite . . . Fossile
d’Angleterre. Mon cabinet. Elle atteint jusqu’a 13 pouces de longueur.”

Lamarck’s original specimens are lost, but from this description it is clear that
this is a smooth species of Baculites with a subacute venter and a flat dorsum. It
is most unlikely that Lamarck’s specimens came from England where the species
is still not known to occur, and from interpretations of the species shortly after
Lamarck it is much more likely that his originals came from the Calcaire a Baculites

366 CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA

in Manche, Normandy. Specimens probably from Manche were described by
Defrance (1816: 160, pl. 22, figs. 1-3) and Blainville (1825: 380, pl. 12, figs. 1-3)
under the name B. vertebralis; in both descriptions it is clear that the species referred
to is B. anceps, and the figured specimen appears to be entirely smooth. Further
specimens from Manche, collected by de Gerville at Valognes, were described by
Deshayes (1831), this time under the correct name B. anceps; the figured specimen
is a short smooth fragment, said to be keeled. The best interpretation of B. anceps
prior to d’Orbigny is that of Bronn (1837), who figured a fine specimen from Manche,
that is 265 mm. long, keeled, with a smooth septate portion and fine ribs on the
body chamber; this was certainly sufficient to fix the identity of the species. The
Swedish specimen figured as B. anceps by Hisinger (1837: 31, pl. 6, fig. 2) has a cross
section that is close to a perfect ellipse and does not belong to this species. In view
of the establishment of B. anceps as a mainly smooth species, it is surprising that
d’Orbigny (1842) chose as his figured specimens two Manche examples that had
large ribs on their body chambers. D’Orbigny was well aware of the variation of the
species between such ribbed forms and entirely smooth forms, and his was the first
good description of this variation. He also stated that the species was known only
from Manche, even though he included (wrongly) Hisinger’s Swedish specimen in
his synonymy. Authors following d’Orbigny added little to his interpretation of
B. anceps. Binckhorst (1861: 42, pl. 5d, fig. 3) referred a specimen to this species
which is, in fact, a Eubaculites with a tabulate venter from the Maastrichtian of
Limbourg. Schliiter (1876) and Griepenkerl (1889) recorded the species from
Germany. Griepenkerl followed d’Orbigny in considering the variety with large ribs
as the normal form, and he proposed the name var. swblaevis for the smooth form,
a name that is not necessary because the smooth form is the dominant form in the
type population. Although the specimen figured by Prestwich (1888: 332, pl. 12,
fig. 16) was labelled ‘‘Upper Chalk” and in the absence of a stated locality would
be taken for an English specimen, it is from Manche, and the best one figured
hitherto; it is 205 mm. long, one half septate with very fine striate ribs, and the other
half smooth body chamber. The German specimen figured by Bohm (1891) as
Baculites valognensis may be an example of B. anceps, but it is a small fragment and
not really recognizable. Nowak (1908) interpreted Bohm’s species as merely a
variety of B. anceps, and figured two Manche specimens, one with fine ribs on the
septate part, the other with somewhat larger ribs on the body chamber. As these
are also part of the normal range of variation in the type population (they are not
like the really boldly ribbed forms) the varietal name is again unnecessary. Nowak
(1908: 328, figs. 1-5 (p.329), pl. 14, figs. 1-5, 10) also proposed a new variety
leopoliensis for a form from the Cretaceous of Poland that has bold ribs on the body
chamber and fine secondaries retained on the venter to a large size. But the whorl
section of this form does not show a consistent keel on the venter, which is the most
characteristic feature of B. anceps, and the variety should be excluded from B. anceps.
No further descriptions or figures of B. anceps have been given.

From the discussion above it is clear that B. anceps was interpreted as a smooth
or finely ribbed species prior to d’Orbigny, and it is now known that smooth forms

CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA 3607

are dominant in the type population. The specimen chosen as neotype is therefore
an almost smooth example and is not like the coarsely ribbed examples figured by
d’Orbigny ; it is the specimen, B.M. (N.H.) 32573, originally figured by Prestwich (1888,
pl. 12, fig. 16), and was from Mantell’s collection, presented to the British Museum
(Natural History) with the label ““Baculites anceps, Normandy’’. It is typical of the

Fics. 2-4. Suture-lines of Baculites. Fig. 2. Baculites anceps Lamarck. Fourth suture-line
from body chamber. Neotype, B.M.(N.H.) 32573, from Lower Maastrichtian, Calcaire a
Baculites, Normandy. x4:°5. Fig. 3. B. anceps Lamarck. Suture-line at cross section
height of 16 mm. B.M.(N.H.) 6408, same horizon and locality. 4:8. Fig. 4. B.subanceps
Haughton. Last suture-line at cross section height of 11-5 mm. C. 52730, from Upper
Campanian, Carimba, Angola. x5.

dominant form of the species, having no constrictions, and only very fine ribs on the
septate part. Plaster-casts of the two best specimens in d’Orbigny’s own collection
(no. 7204) were kindly sent to me by Dr. J. Sornay, but neither is good enough to
be made the type specimen, nor were they the originals of any of d’Orbigny’s figures.
Four specimens from de Vibrayes’ collection in Paris, also sent on loan by Dr. Sornay,
are smaller and less well preserved than the neotype. Amongst the material in the
British Museum (Natural History) from which the above description of the type
population was drawn, the one designated as neotype is the best specimen for which
a definite locality is known (even though this is only ““Normandy’’). It is slightly

3608 CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA

better preserved and more complete than the best of the 47 Valognes specimens
obtained by Sowerby from de Gerville and forming the main part of this collection.

The characteristic feature of B. anceps is the keeled or sharpened venter. Variation
in other characters is considerable, ranging from completely smooth to boldly ribbed
types and including unconstricted and constricted specimens. There is no reason to
believe that any of these should be separated specifically, for all intermediates exist,
even specimens with very weak constrictions, and all are united by the keeled venter.
B. anceps is very common at only one horizon in the Calcaire a Baculites of Manche
(Grossouvre, 1901: 286, the lowest bed), where it has every appearance of forming
a normally variable single population. b. vertebralis Lamarck, which occurs less
commonly in the same bed, has a completely different cross section. The age of
this bed is Lower Maastrichtian.

The specimen described and figured by Desmarest (1817: 49, pl. 2, figs. 4-6) as
B. dissimilis has a whorl section that is close to elliptical with no marked difference
between venter and dorsum. The specific name is not a senior synonym of B. anceps.
The Californian and Japanese specimens described by Matsumoto (1959a: 130-136,
pl. 34, fig. 3; pl. 35, fig. 1) and Matsumoto & Obata (1963: 59-63, pl. 20, fig. 3) as
B. anceps pacificus also lack the keel of B. anceps, and should be excluded from that
species. They belong to B. subanceps as described below.

Baculites subanceps Haughton
Plate 5, fig. 3; Pl. 6, figs. 6, 7; Pl. 7, fig. 1; Text-figs. 4, 13=15

1925 Baculites subanceps Haughton: 278, pl. 14, figs. 6-8.
1959@ Baculites aff. B. anceps Lamarck; Matsumoto: 130, pl. 34, fig. 3; pl. 35, fig. 1.
1963 Baculites anceps pacificus Matsumoto & Obata: 59, pl. 20, fig. 3.

LecToTyPe. South African Museum No. 6829 (PI. 6, fig. 6) from Carimba.

MATERIAL. In addition to the lectotype, ten paralectotypes all numbered 6829
in the collection of the South African Museum, Capetown, and four specimens
in the British Museum (Natural History) (C. 52729-32). All from Carimba.

DEscRIPTION. The largest specimen (PI. 7, fig. 1) is a fragment of a body chamber
with a short part of the flared mouth border preserved. The height and width of
the cross section close to the mouth border are 37 and 30 mm. respectively. This
fragment is 120 mm. long and no part of the septate shell is preserved. Its cross
section is close to elliptical, but has two wide and shallow grooves on either side of
the evenly rounded venter (Pl. 7, fig. 1). The shell is nearly smooth and there is a
long ventral rostrum and a short dorsal rostrum at the mouth border. All the other
specimens are smaller; some (e.g. Pl. 5, fig. 3) have presumably immature, unflared
mouth borders, and the largest final suture-line before a body chamber occurs at a
cross section height of 23-5 mm.; the cross section (Text-figs. 13-15) in all of them
shows a flattened dorsum, a narrower but well rounded venter, and rounded sides;
none has any signs of grooves on either side of the venter. There are no final
crowded suture-lines. The ornament is similar to that of the ribbed forms of B. anceps;
prominent arcuate ribs on the dorsal half of the side are projected strongly forwards

CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA 369

and reduced to striae on the ventral half, then (unlike the ribs of B. anceps) they
increase in strength again and bend slightly back to pass over the rounded venter
as prominent crenulations; there are between 2 and 3 times as many such ribs
crossing the venter as there are arcuate ribs on the side. The ribs are also reduced
to striae across the dorsum and are projected only slightly forwards. All the specimens
bear such ribs except the single largest one which is nearly smooth. There are no
constrictions.

Remarks. Haughton (1928: 278) had “‘numerous examples’’ of this species and
figured three of them. A holotype was not designated, so the whole collection
consists of syntypes and a lectotype designation can be made. The original of
Haughton’s pl. 14, fig. 6 is lost or not available for study, and as this figure does not
show any of the ornament it is not suitable to be a lectotype. The specimen from
which Haughton obtained the cross section of his pl. 14, fig. 8 (refigured here Pl. 7,
fig. 1) is a very large smooth body chamber fragment, with shallow ventral grooves
peculiar to its large size, and is also unsuitable for a lectotype. The lectotype
designated is therefore the medium-sized specimen figured in Pl. 6, fig. 6, which is
half septate, half body chamber, and shows the ornament well. It is one of the best
preserved syntypes. Two further specimens are figured (Pl. 5, fig. 3; Pl. 6, fig. 7;
Text-figs. 13, 15) which show the ornament and cross section at different sizes.
Little variation in the ornament can be detected in the 15 specimens, for all the
medium-sized examples are ribbed and the two largest body chambers become
nearly smooth. The venter is smoothly rounded in all cases with no trace of sharpening
or of a keel.

Fics. 5-15. Cross sections of specimens of Baculites figured in the plates. For details of
individual specimens see plate explanations indicated below. Figs. 5-12. Baculites anceps
wamanrcka hice 5)— elvan ton 4 bigs 61— Pla tic: 4; bies7 — Pll 5) fies 5. Hig. 8 — PG,
ini, ae Jeikee, @) == 1eal, (6), 1alee Be IOree, eo) —— PIL, (6), satay, Sip Vente ery = IPA, Gp sales, 719 Velikex, 3s —— IPI Gy,
fig. 5. Figs. 13-15. Baculites subanceps Haughton. Fig. 13 = PI. 5, fig. 3; Fig.14 = Pl. 6,
Ide (5 lekfeg, a0) —— eal Gy salen G7,

All figures natural size.

370 CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA

The rounded shape of the venter in B. subanceps is sufficient to separate it
specifically from B. anceps, for the keel or sharpened venter of the latter is the one
constant character of an otherwise variable species. No intermediate examples occur
in the type poluations of either species. The Angolan examples described belong to
the subspecies B. subanceps subanceps. In the Pacific region a second subspecies
occurs, B. subanceps pacificus Matsumoto & Obata, which was originally described
as a subspecies of B. anceps. However it has the rounded venter of B. subanceps
with no trace of sharpening as in b. anceps. The Pacific subspecies differs from the
type subspecies in Angola in having many more closely spaced arcuate ribs on the
side of the shell. Comparison of the holotype of pacificus (Matsumoto 1959a: pl. 34,
fig. 3) with the lectotype of subanceps (PI. 6, fig. 6) shows that paczificus has between
two and three times as many arcuate ribs as subanceps. The density of the ribs on
the venter is approximately the same in the two subspecies, as is also the whorl
shape, the shape of the mouth border and the curve of the ribbing. There are no
other differences between the two forms, which appear to be genuine contemporaneous
subspecies that are geographically separate. B. subanceps pacificus can be dated as
Upper Campanian in both Japan and California, while B. subanceps subanceps is
definitely of Upper Campanian age in Angola, as deduced from the associated
Libycoceras and the many heteromorph ammonites.

The only other Baculites known from Angola are the fragments with keeled or
sharpened venters described by Haughton (1925: 279, pl. 14, fig. 9), and the apparently
similar forms described by Haas (1943: 13-15, figs. 15-19) as B. anceps, all from
localities near Capolo. They are poorly preserved and from the wide variety of
forms of the venter, some distortion has probably occurred making specific deter-
mination doubtful. Two Middle or Upper Campanian specimens from Madagascar
figured by Collignon (1938: 88, pl. 6, figs. 4, 5) are also poorly preserved and of
doubtful affinities. The Pondoland and Zululand Baculites described by Woods
(1908) and Spath (1921a) and further Madagascan species described by Collignon
(1931) all appear to be of Santonian age, and the only other high Cretaceous specimen
known from south of Sahara is the example from the Maastrichtian of Nigeria figured
by Reyment (1955: 15, pl. 1, fig. 5) as B. cf. asper Morton.

The most closely related species to B. subanceps is the Polish Upper Campanian
species B. leopoliensis Nowak (1908: 328, pl. 14, figs. I-5, 10), which differs in that
its arcuate ribs are retained to a large size (at least 40 mm. cross section height), its
ribs do not form marked chevrons on the venter, and the thickest part of the arcuate
ribs are approximately at the centre of the side, not dorsal as in B. subanceps.
B. palestinensis Picard (1929: 438, pl. 10, figs. I-7) is another closely related species
from the Upper Campanian of Israel; its ribs are less strongly curved and less
projected on both venter and dorsum than in B. subanceps, and the thickest part of
the arcuate rib is in the middle of the side. The Alpine species B. fuchst Redtenbacher
(1873: 134, pl. 30, fig. 15) and the Californian species B. fairbankst Anderson (1902:
92, pl. 7, figs. 152, 153; 1958: 190, pl. 49, fig. 4) are both based on holotypes that are
too poorly preserved to be interpreted satisfactorily, as has been pointed out by
Matsumoto (1959a@: 134).

CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA 371

Family NOSTOCERATIDAE Hyatt 1894

The difficulties in arriving at a satisfactory generic classification of this family
have been pointed out by Anderson (1958: 195) and Matsumoto (1959@: 157-158).
The character usually considered to be of greatest generic significance is the mode of
coiling of all the whorls, and especially of the adult body chamber; the presence or
absence of tubercles, constrictions and flared ribs are characters used to a lesser
extent. The classification arrived at by Wright (1957: L 222-224) is based mainly on
mode of coiling and is a sound division of the family. Although few species of
Nostoceratidae are known from large collections, in those where ten or more
specimens are known from a single locality (including the Angolan collections of
Didymoceras subtuberculatum sp. nov. and Nostoceras hyatti Stephenson described
below), the mode of coiling shows little variation. At species level it is no more
variable than any other ammonite character, and groups of species with similar
coiling make satisfactory generic divisions. But considerable difficulties arise with
the Campanian—Maastrichtian genera Civroceras Conrad (1868), Didymoceras Hyatt
(1894), Nostoceras Hyatt (1894) and Bostrychoceras Hyatt (1900), to which all the
Angolan examples belong, and these will have to be discussed more fully here.
Wiedmann’s (1962) solution was to refer all these forms to the oldest of them,
Cirroceras (Jouaniceras Basse 1939, was also included as a synonym), but it is open
to the objections that Civroceras is not generically identifiable, Nostoceras is a compact
and useful group of species, and the type species of Bostrychoceras, B. polyplocum
(Roemer), was somewhat mis-interpreted by Wiedmann.

Cirroceras Conrad (1868). TyPE SPECIES: Ammonceratites convadi Morton (1841).
The holotype is from the Upper Campanian or Lower Maastrichtian of New Jersey,
and is a fragment of less than one whorl from the middle growth stage of the
ammonite. It is poorly preserved, crushed and seems to have been non-septate. It
was refigured by Whitfield (1892: 2609, pl. 45, figs. g-1I), and is now apparently lost,
but figures of a plaster cast of it have recently been given by Reeside (1962: 120,
pl. 70, figs. 1-3). Other specimens referred to Morton’s species by Whitfield (1892:
pl. 45, figs. 12, 13) and Weller (1907: 833, pl. 108, figs. 5-8) belong to the well-known
species Nostoceras hyatti Stephenson. Identification of Civroceras must rest on the
holotype alone, but it is clearly too fragmentary to distinguish between Didymoceras
and Emperoceras. It closely resembles one of the superb specimens of Emperoceras
simplicicostatum figured by Whitfield (1902: 68, pl. 25, fig. 2), but it could equally
well be one of several species of Didymoceras (e.g. D. (2) newtont Whitfield 1880:
449, pl. 15, figs. 1-4, or D. hornbyense (Whiteaves), Usher 1952: 103, pl. 27, figs. I, 2,
pl. 28, fig. 2), or a Nostocevas such as N. dvaconis Stephenson (1941: 413, pl. 82,
figs. 5-9). (Emperoceras is quite distinct from the other genera (Didymoceras,
Bostrychoceras and Nostoceras) described here because of its two long parallel arms
in early growth stages (Whitfield 1902)). Discovery of more complete specimens
from the same horizon and locality would hardly settle its identity satisfactorily,
because the doubt would always remain as to whether they really were the same as
the holotype. The absence of early and of adult whorls precludes generic identifica-

372 CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA

tion, and Civvoceras must therefore be considered a nomen dubium, an unusable
generic name.

Apart from Nostoceras which forms a compact, closely defined group (discussed
below), there remain a large number of species to which the names Didymoceras and
Bostrychoceras have been applied with differing interpretations and limits. The
question to be decided is whether species such as B. elongatum (Whiteaves) (Usher
1952: pl. 28, figs. 3, 4), usually considered typical of Bostrychoceras, are to be
separated generically from those like D. hornbyense (Whiteaves) (Usher 1952: pl. 27;
pl. 28, fig. 2), usually considered typical of Didymoceras. The complete range of
variation is perhaps better illustrated by two specimens figured by Stephenson
(1941: pl. 83, figs. 6, 7 and fig. 13) that are very different, and would be referred to
different genera by most workers. There are many species representing different
combinations of tight or loose coiling and presence or absence of tubercles or
constrictions between these extremes, and when the type species of Didymoceras and
Bostrychoceras are examined, both are found to be relatively close to the centre of
the variation.

Didymoceras Hyatt, 1894. TyprE SPECIES: Ancyloceras nebrascense Meek & Hayden
1856. The holotype (Meek 1876: 480, pl. 22, fig. 1) is a half whorl fragment in which
the whorls were probably in contact. A better specimen was figured by Whitfield
(1880: 451, pl. 14, fig. 9, pl. 15, fig. 6) and consisted of two helically coiled whorls in
contact. In the specimen figured by Hyatt (1894: 574, pl. 14, figs. 13, 14) only the
last helical whorl before the body chamber is preserved; this is not in contact and is
followed by a rounded body chamber loop. Regular bituberculation is present on
the body chamber and the last one or two whorls of the spire. Another typical species
is D. hornbyense (Whiteaves 1895) (Usher 1952: 103, pl. 27, pl. 28, fig. 2), in which
only the last whorls of the spire are loosely coiled.

Bostrychoceras Hyatt, 1900. TypE SPECIES: Turrilites polyplocus Roemer 1841.
Wiedmann’s (1962: 198-200) interpretation of this species is open to criticism.
Roemer (1841: 92, pl. 14, figs. 1, 2) figured two syntypes of his species, and Schliiter
(1872: 112) specifically excluded Roemer’s fig. 2 from his synonymy of this species.
But this can hardly be considered as a selection of Roemer 1841, pl. 14, fig. I as
lectotype of the species, because in the next part of his work Schliiter (1876: 135)
included the same fig. 1 of Roemer (and again specifically excluded fig. 2) in a new
species T. saxonicus. This is not corrected in the corrigenda to Schliiter’s work, and
from his wide interpretation of T. polyplocus it is not clear which of Roemer’s two
figures he wished to include in the species. Wiedmann (1962: 198) must be credited
with having selected Roemer’s fig. 1 as lectotype. This lectotype has very irregular
tubercles only on its last whorl just before it becomes uncoiled, and from the way
they are drawn it could even be doubted whether they are tubercles at all. At least
the whole of the closely coiled spire is non-tuberculate in a typical B. polyplocum.
Of the specimens figured by Schliiter (1872) the two non-tuberculate specimens of
pl. 33, figs. 3 and 4 are the most typical of B. polyplocum, while pl. 33, fig. 5 has the
last three whorls loosely coiled and tubercles on the body chamber. The remainder
might all be different species—pl. 33, fig. 6 and pl. 35, fig. 8 are bituberculate and

CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA 373

loosely coiled, pl. 34, fig. 1 is similar but tightly coiled at large sizes, pl. 33, fig. 8 is
constricted and probably tightly coiled, pl. 34, figs. 2-5 has depressed whorls and
has been re-named Cirroceras depressum Wiedmann (1962: 199), and pl. 35, figs. 1-7
have been referred by Wiedmann (1962: 204) to Didymoceras schloenbachi (Favre).
The species B. secoense Young (1963) from Texas differs from B. polyplocum only in
being consistently bituberculate on all whorls. Further work on much larger
collections from Germany is necessary to determine the limits of variation in
B. polyplocum, but it seems most likely that the tightly coiled, non-tuberculate
forms and those with the last one or two whorls loose and tubercles on the body
chamber, are conspecific. A fine specimen of the former type from Madagascar was
figured by Boule, Lemoine & Thevenin (1907: 61, pl. 14, fig. 1). B. andicwm (Stoliczka)
(Kossmat 1895: 143), to which Wiedmann (1962: 200) referred these tightly coiled,
non-tuberculate forms, differs in having constrictions on all whorls and is of Coniacian
to Santonian age. Matsumoto’s (1959@: 159) suggestion that the constricted group
being Santonian and older might be separated subgenerically from the non-constricted
group which are Campanian and Maastrichtian, seems to be defeated by the presence
in the Maastrichtian of such strongly constricted forms as B. sauwndersorum
(Stephenson 1941: 416, pl. 83, figs. 6-8). Another typical species of Bostrychoceras
is B. elongatum (Whiteaves) (Usher 1952: 105, pl. 28, figs. 3, 4).

Thus the type species of Didymoceras and Bostrychoceras are very similar, differing
only in the slightly looser coils and more persistent tubercles of the former. The
difference does not warrant generic separation. A form which is perhaps midway
in morphology between the two type species is D. californicum Anderson (1958: 197,
pl. 72, fig. 6). A large number of other forms carry the range of variation far beyond
the characters of the two type species. B. condamyi (Collignon 1932: 39, pl. 9,
figs. 1, 2) and B. otsukai (Yabe 1904: 14, pl. 3, fig. 9, pl. 4, figs. 1-3) have ribbing
like a typical Bostrychoceras but loosely coiled whorls. A specimen of the latter
species figured by Matsumoto (1959a: 160, pl. 40, fig. 2) differs from a typical
Didymoceras (e.g. Usher 1952: pl. 27) only by its finer ribs and lack of tubercles.
B. boulei (Collignon, 1932: 40, pl. 9, fig. 4) has fine ribs and no tubercles, but very
loosely coiled whorls. D. navarroense (Shumard) (Stevenson 1941: 417, pl. 83,
figs. g-13) is equally loosely coiled but has heavy bituberculation; while D. subtuber-
culatum sp. nov. described below has smaller tubercles and periodic flared ribs.
Amongst the closely coiled species, D. stevensoni (Whitfield 1880) is typical of
Didymoceras except that some examples (Whitfield rgo1: 219, pls. 29, 30) are closely
coiled up to the end of the final whorl, B. colubriformis (Stevenson I941: 412,
pl. 81, figs. 1-3) is dwarf and has constrictions and fine bituberculate ribs, and
B. saundersorum (Stevenson 1941: 416, pl. 83, figs. 6-8) is particularly tightly coiled,
non-tuberculate and has marked constrictions. D. schloenbachi (Favre 1869; see
Basse 1931: 19, pl. 2, figs. 11-15; Wiedmann 1962: 204) is equally tightly coiled,
but is bituberculate and constricted and as its body chamber is not known it might
be a Nostoceras. In addition there are many fragmentary specimens described under
different specific names by Gabb (1864), Meek (1876) and Anderson (1958) that are
not even generically identifiable.

374 CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA

The three main variables—coiling (loose or tight), tubercles and constrictions
(present or absent in each case)—give eight different combinations, to each of which
one or more species could be referred. To use coiling alone as the basis for generic
division would leave a large number of intermediate species that have partly loose
whorls. As the choice is between one genus or about eight genera, all these forms
are best referred to Didymoceras Hyatt, of which Bostrychoceras Hyatt is considered
a subjective synonym.

Nostoceras Hyatt 1894. TyPE species: N. stantont Hyatt. The two syntypes
were figured by Stephenson (1941: 407, pl. 80, figs. 2-5) together with several other
species of the genus. This is a relatively closely defined genus, characterized by a
closely coiled spire followed by a U-shaped retroversal body chamber that breaks
away suddenly from the spire. In Nostoceras s.s. the body chamber hangs vertically
below the spire, in the subgenus Anaklinoceras Stephenson (1941: 414) it turns
upwards and surrounds the spire. All have well developed bituberculate ribbing on
all whorls. Most of the known species are the North American forms described by
Anderson & Hanna (1935: 22), Stephenson (1941) and Anderson (1958). In addition
there are the Angolan forms described below, some undescribed badly crushed
examples from Syria and Iraq, and possibly N. schloenbaci (Favre 1869—see above),
N. pauper (Whitfield) (Reeside 1962: 118, pl. 68, figs. 10-13), N. natalense (Spath
Ig2ta: 248, pl. 22, fig. 2) and N. subangulatum (Spath 1921a: 250, pl. 22, fig. 3) of
which the body chambers are not known.

In the descriptions of the Angolan fauna the following terms are used for the
helically coiled forms. With the spire in an upright position and the apex pointing
upwards, the upper part of the whorl is the upper surface between the venter (the
siphuncle is usually just above the outermost point of the whorl) and the dorsum,
the lower part of the whorl is the lower surface between venter and dorsum. When
the whorls become detached and form a U-shaped loop as in Nostoceras, the ornament
of the spire becomes twisted so that what was the upper part of the whorl forms the
back of the loop, while what was the lower part of the whorl forms the front of the
loop. The venter runs around the periphery of the loop (or occasionally just to the
back of the periphery).

Genus DIDYMOCERAS Hyatt 1894
Didymoceras subtuberculatum sp. nov.
Plate 7, figs. 2-6, Pl. 11, fig. 4

HOLoTyPE. C. 52701 (Pl. 7, fig. 2) from 1 km. north of Egito, Angola.

MATERIAL. In addition to the holotype, 16 specimens, including 15 paratypes
(C. 52693, C. 52695-709) and C. 52694 which shows some variation. Same locality.

Diacnosis. The spire consists of a loose helicoid spiral, dextrally or sinistrally
coiled, distance between adjacent whorls in uncrushed material roughly equal to
cross section diameter of shell at that point. Earliest whorls and shape of adult body
chamber not seen in material preserved. Whorl section approximately circular at

CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA 375

all growth stages seen. Ornament consists of ribs, tubercles, constrictions and
flared ribs, all developed at all growth stages. Ribs fine and dense and not interrupted
on either venter or dorsum; they cross the dorsum radially, are inclined backwards
on both upper and lower sides in crossing from dorsum to venter, but the inclination
is considerably more on the upper side, so that they are inclined forwards in crossing
the venter from upper to the lower side. Occasional ribs bifurcate on upper and
lower sides and a few intercalated ribs cross the venter. Three or four flared ribs per
whorl, present on all the whorls preserved, flares often immediately preceded by a
slight constriction. Two rows of tubercles occur on all whorls; upper row just below
mid-ventral line (i.e. line of siphuncle) and lower row just ventral of middle of lower
surface. These paired tubercles joined by two ribs with 2 to 6 non-tuberculate ribs
between each pair; much more widely spaced flared ribs usually coincide with
tubercle spacing and are therefore tuberculate.

Remarks. Of the 17 fragmentary specimens of this species, Io are dextrally
coiled and 7 sinistrally coiled. Only a few are not distorted or crushed. Four of the
smallest specimens that are relatively uncrushed (Pl. 7, figs. 4, 5) show a loose
helical spiral that must be close to the original shape of the conch. Two of the
medium-sized specimens are crushed by pressure along the axis of the spire so that
the whorls are nearly in contact, but one of these is selected as holotype for its has
14 complete whorls and shows the characters of the species better than any other
specimen (Pl. 7, fig. 2). Two other specimens are crushed by pressure at right angles
to the spire axis and are less well preserved (PI. 7, fig. 3). The largest specimens are
only short fragments but are not badly crushed and show the whorl shape and
ornament well (Pl. 7, fig. 6). The largest and smallest whorls preserved have cross
section diameters of 43 mm. and 7 mm. respectively. Suture-lines are poorly
preserved and difficult to follow in all specimens, but septal surfaces up to 40 mm.
diameter occur in several of the large specimens, indicating that adults reached sizes
at least a half to one whorl larger than the largest fragment preserved. None of
them shows evidence of modified adult body chamber coiling. Significant variation
from the remainder of the collection can only be seen in one specimen: C. 52694 is
a short septate fragment with a whorl section diameter of 34 mm., and has particularly
strongly curved and oblique ribs which do not appear to have any tubercles.

Spath (1951: 8; 1953: 49) made two specific determinations for these specimens:
“Bostrychoceras polyplocum (Romer) Schliter, pars’ and “‘Bostrychoceras sp. nov.
(cf. punicum?, Pervinquiere)”’. The second determination can be discarded for it
was presumably given to some of the smaller specimens, which after extraction from
the matrix have proved to be the same as the remainder of the collection. The
reference to part of Schliiter’s interpretation of Didymoceras polyplocum is presumably
to the bituberculate and loosely coiled specimens (Schliiter 1872: pl. 33, fig. 6,
? pl. 34, fig. 1, pl. 35, fig. 8) that have been shown above (p. 372) to be different from
the restricted D. polyplocum. There are no flared ribs on these specimens and only
one of them (pl. 35, fig. 8) has a constriction on what appears to be the body chamber,
so they are probably specifically distinct from the flared and constricted Angolan
forms. In fact the 17 specimens of D. subtuberculatum show little variation, and the

376 CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA

specific diagnosis drawn from them is certainly not wide enough to include the
German forms.

There are few other Campanian or Maastrichtian forms that are closely comparable
with D. subtuberculatum. The Pondoland and Zululand specimens figured by Woods
(1906: 339, pl. 42, figs. 4, 5) and Spath (1921a: 252, pl. 24, fig. 2) appear to be loosely
coiled and two of them have flared ribs, but none has any tubercles and they are
only small fragments. Several loosely coiled examples from Madagascar figured by
Collignon (1932: 40, pl. 9, fig. 4; 1938: 87-88, pl. 5, fig. 4, pl. 6, fig. 2) are also without
tubercles or flares.

At first sight D. subtuberculatum seems to resemble several Turonian to Santonian
species of Hyphantoceras, such as the Japanese species H. venustum (Yabe 1904:
II, pl. 5, figs. 1, 2 (holotype), pl. 3, fig. 4—Euhyphantoceras maestrichtiense Shimizu
1935, 1s an objective synonym and is Santonian, not Maastrichtian) and the north
American species H. buttense, H. ceratopse and H. laqueum described and figured by
Anderson (1958: 207-210), all of which might be synonyms of H. venustum (see
Matsumoto 1959@: 158). There is even some resemblance to Schliiter’s figures
(1872, pl. 32, figs. 13-20) of the type species Hyphantoceras reussianum (d’Orbigny).
In Hyphantoceras, however, the arrangement of the ornament is different; the flared
ribs are more frequent and each bears 2 to 4 tubercles, while all the ribs between the
flares are non-tuberculate; in D. subtuberculatum the flares are fewer and more
widely spaced, and tubercles occur at smaller intervals on non-flared as well as
flared ribs.

Didymoceras cf. californicum Anderson
Plate 8, fig. 1

1958 Didymoceras californicum Anderson: 197, pl. 72, fig. 6.

MATERIAL. One specimen, C. 52727, from Carimba, Angola.

DEscRIPTION. The specimen consists of one and a quarter coiled whorls and
part of another smaller whorl. The whorls are in contact, and siphuncle and septa
occur up to the largest stage preserved. The whorl section is approximately circular
and the diameter of the largest whorl is 23 mm. The ornament consists of simple
ribs, approximately 42 per whorl, which cross the venter inclined at an angle to the
whorl but roughly parallel to the axis of the spire. The ribs bear two rows of small
insignificant tubercles; the upper row is exactly along the line of the siphuncle, while
the lower row is some distance below this. Only one rib bifurcates at a tubercle in
this specimen, all the remaining ribs being single.

REMARKS. This specimen and Anderson’s species are readily compared with
Didymoceras polyplocum (Romer) and D. elongatum (Whiteaves). The differences
between the three species are mainly the density of the ribs, and the occurrence of
small tubercles on the septate whorls of D. californicum. At approximately the size
of the specimen described here, the rib density is 25 per whorl in the lectotype of
D. elongatum (Usher 1952: 105, pl. 28, fig. 3), about 42 per whorl in the present
specimen, and 55-60 per whorl in D. polyplocum (Rémer 1841: pl. 14, fig. 1; Schliiter

CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA 377

1872: pl. 33, figs. 3-5). The Angolan specimen differs from the other two species by
its regular small tubercles (in D. polyplocum tubercles are irregular and rare on all
whorls before the body chamber). Anderson’s holotype (the only specimen) came
from the Upper Campanian or Lower Maastrichtian of California, and shows the
uncoiled body chamber commencing at about the maximum size attained by the
Angolan specimen. Agreement in whorl section, coiling and ornament is close,
except that rib bifurcation at tubercles is probably more common in the Californian
specimen.

The only comparable African specimens are those figured by Basse (1931: 18,
pl. 1, figs. 16, 17) from Madagascar and by Reyment (1955: 15, pl. 1, fig. 4) from
Nigeria; both are Maastrichtian, but are fine-ribbed and closer to D. polyplocum than
to the Angolan specimen.

The Texan species D. secoense (Young 1963: 42, pl. 3, figs. 1-5, pl. 4, figs. 4, 8;
Adkins 1928: pl. 37, figs. 1, 3) differs from D. folyplocum only in its possession of
regular bituberculation on every second or third rib. It resembles D. californicum
but its rib density is greater.

It seems unlikely that D. californicum is a synonym of D. hornbyense (Whiteaves)
as Claimed by Matsumoto (1960: 54), for it has a considerably smaller apical angle,
its tubercles are much smaller, and it shows no evidence of slow loosening of the last
one or two septate whorls before the body chamber as in D. hornbyense.

Didymoceras cf. hornbyense (Whiteaves)
Plate 8, fig. 4

1895 Hetevoceras hornbyense Whiteaves: 316.

1903 Hetevocervas hornbyense Whiteaves: 332, pl. 42, figs. 1-4.

1921a Didymoceras hornbyense (Whiteaves) Spath: 251.

1925 Didymoceras hornbyense (Whiteaves); Haughton: 276, pl. 15, fig. 2.

1952 Nostoceras hornbyense (Whiteaves) ; Usher: 103, pl. 27, figs. 1, 2, pl. 28, fig. 2, pl. 31, fig. 23.

MATERIAL. One body chamber fragment, C. 52737, from Barra do Dande, Angola.

Remarks. The single specimen is well preserved with neither distortion nor
crushing, and consists of a quarter of a whorl of body chamber 95 mm. long with the
last septum preserved. The whorl section is circular, 27 mm. diameter at the smaller
end, 33 mm. at the larger end. The coiling is dextral. Towards the smaller end the
venter is considerably eroded and the ribs and tubercles almost removed. On the
dorsum the ribs are reduced to small striae. Pairs of large tubercles occur irregularly
on every third or fourth rib, and there are some looped ribs between the tubercles.

Another fragmentary example from Angola, figured by Haughton, is smaller than
the present specimen, but has closely similar ornament. Both specimens show the
typical characters of D. hornbyense as seen in Whiteaves’ original specimens and
Usher’s (1952: 103) revision. The example figured here compares well with the
largest figured by Usher (1952: pl. 27). Reference to Didymoceras rather than to
Nostoceras is favoured on account of the large size of the body chamber, which does
not form the hanging U-shaped body chamber characteristic of Nostoceras. Its
possible relationship with N. helicinwm is discussed below.

378 CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA

Didymoceras cf. angolaense (Haughton)
Plate 8, fig. 2

1925 Nostocervas angolaense Haughton: 275, pl. 15, fig. 1.
?1943 + Nostocevas cf. angolaense Haughton; Haas: 5-6, figs. 2, 8.

MATERIAL. One specimen, C. 52739, from Barra do Dande, Angola.

ReMARKs. The specimen consists of four whorls closely coiled into a dextral
helical spire of small apical angle. The whorl section is rounded between the ribs,
but is angular over the tubercles as described by Haas (1943: 5, fig. 2). The ribs,
tubercles and constrictions are similar to those in the type specimen described by
Haughton, although the 20-22 tubercles in each row of the present specimen appear
to be slightly more than in the holotype. There are 33 ribs on the last whorl, but
no suture-lines can be seen in this specimen, which is preserved as a limonite-stained
shell filled with crystalline calcite. The specimens described by Haas are fragmentary
and have no distinct ribs, and cannot be referred with certainty to this species.

The species is referred to Didymoceras rather than to Nostoceras because the last
whorl of the holotype is loose, and does not change suddenly to the downwards
curving body chamber typical of Nostoceras. The most closely related species are
D. splendidum (Shumard) (Stephenson 1941: 415, pl. 82, figs. 1-4) from the Lower
Maastrichtian of Texas and D. excelsus (Anderson 1958: 194, pl. 72, fig. 4) from the
top of the Campanian or the Lower Maastrichtian of California. Both these species
differ in having even more acutely angled spires, a pair of tubercles on each rib and
no non-tuberculate ribs as in D. angolaense.

Genus NOSTOCERAS Hyatt 1894

Nostoceras hyatti Stephenson
Plateio; Ply 10) tigen Vext-fies 16

1892 Heteroceras convadi (Morton); Whitfield: 269-271, pl. 45, figs. 12, 13, non figs. 9-11, 14.
1907 Heteroceras conradi (Morton); Weller: 833, pl. 108, figs. 5-8.

21935 ‘“‘Hamites’’ vancouverensis Gabb; Anderson & Hanha: 23, pl. 7, figs. 2-4, pl. 8, fig. 5.
1941 Nostocevas hyatti Stephenson: 410, pl. 81, figs. 9-12.
1951 Didymoceras sp. nov. ind., Sornay: 274, pl. 4, fig. 4.
1962 Nostocevas sp., Reeside: 119, pl. 69, figs. 7-12.

MATERIAL. I0 specimens, C. 52740-43, C.52747-52, from Barra do Dande,
Angola.

Description. The collection consists of seven looped body chambers, one having
the last spiral whorl preserved, the other six having a short septate portion or the
last septum preserved and the entire spire missing, and three fragments of body
chambers. The spire is coiled dextrally in four specimens and sinistrally in three
(the coiling is not determinable in the three fragments). The last whorls of the spire
are in contact right up to the point at which the rapid change to the U-shaped body
chamber occurs. The two limbs of the body chamber are nearly straight and close
together, leaving only a narrow gap between them which diminishes in width at the

CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA 379

level of the mouth border. The length of the body chamber varies slightly, for in
some the last septum is at the beginning of the first straight arm opposite the mouth
border, while in others it occurs earlier at about the position at which the whorl
breaks away from the closely coiled spire. The axis of the spire is inclined at a small
angle (c. 20°) to the plane of the body chamber. The whorl section is approximately
circular throughout although the diameter at right angles to the plane of the body
chamber increases on the middle part of the body chamber in most examples. The
ribs are sharp and mainly single throughout but occasional irregular bifurcation
occurs at the tubercles or at the edge of the dorsum, and irregular looping or
zigzagging occurs between some of the tubercles. The strength of the ribbing is
considerably reduced on the dorsum of all whorls. On the body chamber the ribs
are markedly stronger and more widely spaced than on the spiral whorls but they
tend to increase in density again on approaching the mouth border. On the spiral
whorls the ribs are inclined at a small angle to a whorl section plane; on the body
chamber ribs are generally more radial (i.e. annular) but they are somewhat irregular
and on the back part (see descriptive terms for helically coiled ammonites p. 374
above) of the first straight limb the ribs are arched upwards and particularly strong.
Narrow constrictions occur at wide intervals on the spiral whorls, but not on the
main part of the body chamber. The mouth border is immediately preceded by a
constriction, then a collar-like rib, followed by a narrow flat portion up to the
slightly sinuous mouth border. Two rows of medium sized tubercles occur fairly
constantly on alternate ribs on the spiral whorls; the upper row overlies the siphuncle,
the lower row occurs just below the line of contact between adjacent whorls. On
well preserved parts complete with the shell the tubercles are elongated into short
pointed spines. On the body chamber the tubercles occur on every rib, gradually
L
4

ph Pd

Fics. 16,17. Suture-lines of Nostoceras. Fig. 16. Nostocevas hyatti Stephenson. Last suture-
line of an adult at 21 mm. ventro-dorsal diameter. C. 52743, from Upper Campanian,
Barra do Dande, Angola. x3. Fig. 17. N. obtusum sp. nov. Suture-line at 10 mm.
ventro-dorsal diameter. Holotype, C. 52744, from Upper Campanian, Barra do Dande,
Angola. x5.

380 CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA

increasing in size to become large round the U-shaped bend, then rapidly diminishing
towards the mouth border. The line of the two rows moves outwards on the first
part of the body chamber until they are situated on the periphery of the main bend
and the final limb of the body chamber. One dextrally coiled specimen shows half a
complete suture-line lying to the right of the siphuncle and the left of the dorsum
(i.e. on the “top” of the whorl) (Text-fig. 16). The first and second lateral saddles
are similar in shape and size, both being divided into two by a minor lobe of moderate
depth then each half divided into two again. The dorso-lateral saddle is smaller, but
is also bifid and is bounded by the short narrow dorsal lobe in the middle of the
dorsum. The first and second lateral lobes are large and deep and each is divided by
a large minor saddle.

The largest and smallest specimens have mouth border diameters of 27 mm. and
22 mm., while the transverse and ventro-dorsal diameters in the middle of the loop
of the largest specimen are 29 mm. and 23 mm. respectively. The distance between
the mouth border and the lowest point of the periphery of the loop varies between
45 and 65 mm. The largest diameter of the single helically coiled whorl preserved
is 37 mm. at the point of break away of the body chamber, and at this point the
cross section diameter is 17 mm.

REMARKS. None of the determinations given by Spath (1951: 10; 1953: 50)
appears to fit these specimens. Stephenson’s originals consist of both spire and body
chamber from the top Campanian or Lower Maastrichtian of Texas, and the Angolan
examples agree with them in all respects. The other specimens listed in the synonymy
are all body chambers only. Whitfield, Weller and Reeside figured five fine body
chambers from New Jersey that show the normal characters of N. hyatti; the
interpretation of Heteroceras conrad: (Morton) has been discussed above (p. 371)—it
cannot be shown to be a Nostoceras and it is certainly not conspecific with N. hyatt.
The two body chamber fragments from California figured by Anderson & Hanha
also agree closely with N. hyatt; the interpretation of Hamites vancouverensis Gabb
(1864: 70, pl. 13, fig. 18) is difficult because the holotype is a small fragment, and
again it is most unlikely to be the same as N. /yatti: because of its larger size and
different tuberculation. Matsumoto (1960: 54) was probably correct in uniting
H. vancouverense, Didymoceras fresnoense and Exiteloceras bennisoni of Anderson
(1958: 197, pl. 68, fig. 2; 201, pl. 72, fig. 7); all differ from Nostoceras in their open
or rounded-U-shaped body chambers, and belong to either Dzdymoceras or
Emperoceras. Another North American top Campanian or Lower Maastrichtian
species, Ammonites cooperi Gabb (1864: 69, pl. 14, fig. 23), included in H. vancowverensis
by some authors, is also difficult to interpret because of a fragmentary holotype.
The interpretations of Whiteaves (1903: 336, pl. 43, fig. 1) and Usher (1952: 107,
pl. 29, fig. 1) are probably correct and put A. cooperi into the genus Emperoceras.
Finally the single body chamber figured by Sornay (1951: 274, pl. 4, fig. 4) is from
Barra do Dande, Angola, and is a good example of N. /yatti. It closely resembles
one of the examples figured here (PI. 10, fig. 1).

Nostoceras lvyatti is characterized by its large size and bold ribs and tubercles.
N. sternbergi Anderson & Hanha (1935: 22, pl. 7, fig. 1) differs in having finer ribs

CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA 381

and smaller tubercles, N. dvaconis (Stephenson 1941: 413, pl. 82, figs. 5-9) has finer
ribs and a depressed spire of high apical angle, N. kernense (Anderson 1958: 196,
pl. 65, fig. 1) has regular plicate ribbing, and N. mexicanwm (Anderson 1958: 196,
pl. 58, fig. 3) has finer ribs and small irregular tubercles. The species is known only
from Texas, New Jersey, California and Angola.

Nostoceras cf. kernense (Anderson)
Plate 8, fig. 6

1958 Didymoceras kernense Anderson: 196, pl. 65, figs. 1, 2.

MATERIAL. One specimen, C. 52746, from Barra do Dande, Angola.

Remarks. This fragment of a U-shaped body chamber is compared with
Anderson’s species because of its markedly branching ribs. It can be seen from the
figure that the position of branching, density and angle of the ribs show a close
resemblance to Anderson’s holotype. In some places the branching is virgatotome
with up to three secondary ribs leaving the primary rib in succession. The Angolan
specimen differs in being considerably smaller and by having shorter straight arms
on the body chamber (judging from the rapid narrowing of the gap between them).
In a few places where the shell is preserved the ribs can be seen to cross the venter
as in Anderson’s holotype, but most of the specimen is an internal mould on which
the band between the rows of tubercles is nearly smooth.

The only comparable species is N. stervnbergi Anderson & Hanha (1935: 22, pl. 7,
fig. 1) from California. This shows similar multiple rib branching, but it has
constrictions and differs in details of ribbing, including a sudden change to bold ribs
on the final straight limb.

Nostoceras rotundum sp. nov.
Plate 10, fig. 3

1951 Didymoceras angolaense Sornay: 274, pl. 4, figs. 1-3.

HOLOTYPE. C. 52745, the only specimen, from Barra do Dande, Angola.

Diacnosis. Medium sized species of Nostoceras, with close-coiled helical whorls,
followed by a hanging body chamber consisting of a semicircular loop. Ornament on
helical coils consists of 14 to 15 tubercles per whorl and weak ribs; tubercles and
moderately strong ribs on body chamber.

DESCRIPTION. The single specimen in the present collection consists of three
whorls closely coiled into a dextral spire, followed by a body chamber loop which
breaks suddenly away from the spire and is angled obliquely downwards forming
a nearly perfect semicircular loop; the mouth border faces obliquely upwards towards
the last whorl of the spire. Suture-lines are too poorly preserved to reveal details,
but the last suture-line is clearly seen to occur on the penultimate whorl directly

382 CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA

above the point at which the loop leaves the spire, so that the body chamber consists
of the whole of the last whorl of the spire plus the loop. The angle between the plane
of the loop and the axis of the spire is 45°. Whorl sections in the spire are roughly
circular with a small flat portion at the position of contact between whorls, and in
the loop the transverse diameter is slightly greater than the ventro-dorsal diameter.
Ornament consists of obliquely aligned pairs of tubercles forming two rows. On
the spire the upper row forms the outermost point of the whorl and contains
14 tubercles per whorl, while the lower row occurs above the position of contact
between whorls and contains 15 tubercles per whorl. The tubercles increase slightly
in strength on the loop and the rows twist so that the lower row occurs around the
outermost periphery of the loop, while the upper row goes onto the back of the loop.
Ribs are poorly developed on all whorls. Between the rows of tubercles on the spire
and the loop only vague undulations occur, but above and below the rows of tubercles
weak ribs occur on the spire, and these strengthen on the loop to form simple curved
ribs above the upper row and both simple and plicate ribs below the lower row. The
dorsum of the loop is smooth. The siphuncle occurs just above the upper row of
tubercles. No constrictions occur on any part, but just before the end of the body
chamber the whorl contracts laterally, then flares out and ends in a gently sinuous
mouth border of exactly circular section. Diameter of the mouth border 23 mm. ;
diameter of the semicircle of the loop 52:5 mm.; total height of specimen as preserved
88 mm.; total height extrapolated to apex 110-115 mm.; diameter of the final spiral
whorl 40 mm.

REMARKS. From the description and figures of Sornay’s single specimen from
Barra do Dande it is difficult to identify his specimen with the one figured here.
However Sornay’s original was kindly made available on loan by Dr. L. Cahen,
Director of the Musée royal de 1’ Afrique centrale, Tervuren, and the great similarities
between the two were then revealed. Sornay’s specimen consists of three-quarters
of a whorl coiled into a sinistral helical spire, followed by a downwards twisting
portion, then two-thirds of a semicircular loop. On the spiral whorl there is a marked
depression where the whorls were in contact right up to the point where the body
chamber breaks away suddenly from the spire. The final suture-line is at the
beginning of the spiral whorl, so that the body chamber occupied three-quarters of
the last whorl of the spire plus the loop. From a comparison with the holotype it is
probable that the mouth border is only just missing; the pair of tubercles before the
broken aperture are probably the last ones. The tubercles and ribs agree exactly
with those of the holotype. The diameter of the final spiral whorl is 54 mm., and
the cross section diameter close to the mouth border is 29 mm.

The two specimens described above agree in having a semicircular loop with no
straight arms, a body chamber that occupies the last whorl of the spire as well as the
loop, bold ribs on the last part of the loop, and large tubercles throughout. These
characters serve to distinguish the species from N. /yatti which has distinct straight
arms in the loop, a body chamber occupying only the loop, and ribs dominant over
tubercles on all but the bend of the loop. Reference of N. votwndwm to Nostoceras
or Didymoceras is arbitrary, and it is included here in Nostoceras because of its tightly

CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA 383

coiled spire and large tubercles. The new specific name, N. votundum, is necessary
because NV. angolaense (Sornay 1951) is pre-occupied by N. angolaense Haughton,
1925. Specimen C, 52745 is chosen as holotype rather than Sornay’s larger specimen
because it is more complete and free from matrix.

N. mariateresianum Haas (1943: 6, 7, figs. 1b, 9), a closely related species from
Angola, is known only from a single fragment that has similar ornament with
dominant tuberculation, but has 22 to 24 tubercles per whorl in each row and 2 to 3
constrictions per whorl. Another Angolan species Didymoceras angolaense (Haughton),
has a smaller apical angle, sharp ribs and small tubercles and a loose Didymoceras
body chamber. The Zululand species Nostoceras (?)subangulatum (Spath 1g921a: 250,
pl. 22, fig. 3) has stronger ribs on the spiral whorls than in N. votundum, and it is
close to Didymoceras (or ? Nostoceras) stevensont (Whitfield 1880: 447, pl. 14, figs. 5-8;
Igor: 219, pls. 29, 30). Whitfield’s (1901) figured specimen, though much larger,
shows a similar loop to that of N. rotundum.

Nostoceras helicinum (Shumard)
Plate 8, figs. 3, 5

1861 Turrilites helicinus Shumard: tot.

1894 Nostocevas helicinum (Shumard) Hyatt, 573.

1941 Nostocevas helicinum (Shumard); Stephenson: 410, pl. 80, figs. 11, 12.
1943 Nostocevas helicinum (Shumard); Haas: 2-5, figs. Ia, 6, 7.

MATERIAL. Two specimens, C. 52738 and C. 52753, from Barra do Dande, Angola.

REMARKS. Both specimens are sinistrally coiled with the whorls in contact, the
larger specimen, C. 52738, consisting of one whorl with a maximum diameter of
30 mm., the smaller specimen, C. 52753, consisting of nearly two whorls, the maximum
diameter of the larger being 24 mm. Although suture-lines are not well preserved
the larger specimen appears to have three-quarters of a whorl of presumably immature
body chamber, while the smaller specimen is septate up to shortly before its aperture.
Deep narrow constrictions occur at roughly 180° intervals on both specimens, and
pairs of small tubercles are present on all whorls.

Two Angolan specimens were described and figured by Haas (1943: 2-5), and the
two further specimens now figured agree with these in all respects. Haas’s description
was much more detailed and complete than that of Stephenson (1941: 410, pl. 80,
figs. II, 12) who designated the neotype of the species. The four Angolan specimens
belong to the normal variety of N. helicinum, which has fine ribs and a spire angle
of 80-go0°. Two varieties that have been separated are N. helicinum var. humile
Stephenson (1941: 412, pl. 81, figs. 4-6) which has a more depressed spire (larger
spire angle) and rather coarser ribs and tubercles, and var. crassum (Stephenson 1941:
412, pl. 81, figs. 7, 8) which has much coarser ribs and tubercles. N. stantoni and its
varieties (Stephenson 1941: 407-410, pl. 80, figs. I-10) have a smaller spire angle and
few tubercles, N. hyatti has a smaller spire angle and coarser ribs and tubercles, and
the somewhat similar species Didymoceras hornbyense (Whiteaves) (Usher 1952: 103,
pl. 27, pl. 28, fig. 2) attains much larger sizes and has larger ribs and tubercles.

384 CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA
Nostoceras (2?) obtusum sp. nov.

Plate ro, fig. 2; Text-fig. 17

HoLotyPe. C. 52744, the only specimen, from Barra do Dande, Angola.

Diacnosis. Coiled whorls consisting of depressed, obtuse-angled closely coiled
spire; adult body chamber unknown. Two rows of tubercles are the dominant
ornament, with small ribs crossing the whorl above and below them and low ribs
connecting tubercles between rows.

DeEscrRIPTION. The single specimen consists of two whorls closely coiled into a
sinistral helical spire that has a large apical angle of 125-130°. The first one and a
quarter whorls are septate and the final three-quarters of a whorl is body chamber,
probably that of an immature specimen, for the final septa are not approximated
and there are no signs of adult body chamber modification of the mode of coiling.
The whorl section has angles at the position of the tubercles, a flat or slightly
impressed portion at the position of contact with earlier whorls just above the dorsum,
and rounded upper and lower sides. Tubercles are the dominant feature of the
ornament; the upper row occurs just below the mid-ventral line and forms the
outermost point of the whorl, while the lower row occurs near the middle of the
lower side and is the lowest point of the whorl. On the upper side of the whorl small
straight radial ribs are connected to the tubercles in pairs, and on the dorsal side of
the lower row of tubercles similar small ribs are connected singly or in pairs to the
tubercles. These ribs are greatly reduced in crossing the dorsum. Between the two
rows of tubercles low undulations join or occasionally zigzag between opposite
tubercles; by comparison with the ribbed part of the whorl this band is nearly
smooth. There are no constrictions. Maximum diameter of the final whorl 47 mm. ;
width of ‘‘umbilicus” on underside 20 mm.; whorl height (dorsum to top of outer
tubercle) 15 mm.; the outer whorl has about 55 ribs on the upper side of the whorl,
about 31 tubercles in the upper row, 25 tubercles in the lower row and 41 ribs on
the lower side of the whorl. As much of the suture-line as is visible is shown in
Text-fig. 17.

REMARKS. The combination ofa large apical angle, giving a very depressed spire,
slender whorls, angled whorl section, and large tubercles with the lower row in
the middle of the lower surface, serves to distinguish this species from any other
Nostoceras. Other flat whorled species and varieties, such as N. helicinum var.
humile Stephenson (1941: 412, pl. 81, figs. 4-6) and N. dvaconis (Stephenson 1941:
413, pl. 82, figs. 5-7, 8, 9), have much smaller tubercles and round whorl sections.
The Zululand species NV. (?) natalense Spath (1921a: 248, pl. 22, fig. 2) has much
larger and more massive whorls, with large tubercles, bold ribs and a small “umbilicus”
on the underside of the spire. N. obtusum is referred to Nostoceras rather than to
Didymoceras because of the tight coiling and the ornament, which compare with other
more completely known species of Nostoceras.

CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA 385

Family DIPLOMOCERATIDAE Spath 1926
Genus POLYPT YCHOCERAS Yabe 1902
Polyptychoceras pseudogaultianum (Yokoyama)
late nin shion 2

1890 Ptychoceras pseudogaultianum Yokoyama: 181, pl. 20, figs. 1, 2, ?3.

MATERIAL. 10 specimens, C. 52718—26 from 1 km. north of Egito, and C. 52754
from Barra do Dande, Angola.

DESCRIPTION. The single specimen from Barra do Dande consists of a straight
arm 57 mm. long, followed by a complete U-bend and a short portion of the next
larger straight arm 11 mm. long. The whorl section is nearly circular throughout,
being 6:5 mm. diameter at the smaller end and 9 mm. X I0 mm. at the larger end.
The two arms are close together, the maximum width of the gap between them near
the hook being only I mm. The ribs are relatively widely spaced and are broad and
flattened on the internal mould. On the side of the whorl they are inclined slightly
forwards towards the venter, which they cross unchanged, but the dorsum is smooth
or is crossed by striae only. Immediately before the hook there is a constriction
preceded by a collar on the venter. On the hook the ribs are smaller and more
striate, and just beyond the hook there is a second constriction on the short portion
of the larger arm. No suture-lines are visible on this specimen.

The other specimens are all fragments of straight arms up to 50 mm. long and have
dimensions similar to the single specimen described above. All have slightly oblique
broad ribs, and two of them have shallow constrictions between two adjacent ribs.
Septal surfaces and fragments of suture-lines are present in several specimens.

REMARKS. Spath (1953: 49, 50) determined the Barra do Dande specimen as
Phylloptychoceras sp. nov. and the Egito specimens as Polyptychoceras cf. pseudo-
gaultianum (Yokoyama). However, all are clearly conspecific and are referred here
to Yokoyama’s species, from which they show no significant differences. Yokoyama
(1890: pl. 20, figs. 1-3) figured three syntypes, the two largest (figs. 1, 2) being
comparable in size with the Angolan specimen and showing the same type of ribs,
while the smallest (fig. 3) is more densely ribbed and has occasional constrictions.
Wiedmann (1962: 185) referred this fine-ribbed syntype to the north German Upper
Santonian and Campanian species P. (?) obliquecostatwm (Schliiter). Whether this
is correct or whether the specimen falls within the variation of P. pseudogaultianum
must await the analysis of a larger Japanese topotype collection, and also a proper
generic assessment of Schliiter’s species which is known only from short straight
fragments. P. pseudogaultianum occurs in both the Santonian and Campanian of
Japan. Four other Japanese species, P. havadanum (Yokoyama), P. subquadratum
(Yokoyama), P. subundulatum (Yokoyama) and P. obstrictwm (Jimbo) differ in size
and details of ribbing.

P. vancouverense (Whiteaves) (Usher 1952: 101, pl. 26, figs. 5, 6) is a closely related
species from the Upper Campanian of British Columbia. It is slightly larger and has

386 CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA

more widely spaced, flattened band-like ribs than P. pseudogaultianum. The
Graham Land specimens described by Spath (1953: 18, pl. 7, fig. 5) as Polyptychoceras
sp. Juv. indet. are indeterminable and could equally well be Glyptoxoceras or
Diplomoceras.

Subptychoceras has ribs arranged in groups on low bulges and Phylloptychoceras
has undulating folds on the sides of the whorl and some striae; both are best con-
sidered subgenera of Polyptychoceras. The lectotype of Phylloptychoceras sipho
(Forbes), the type species of the subgenus, is figured here (Pl. 11, fig. 1) because
previous determinations of this species have had to rely on the inadequate drawings
of Forbes (1846: 118, pl. 11, figs. 5a-g) and Stoliczka (1865: 194, pl. go, figs. 5-9),
and the figure of the suture-line given by Spath (1953: pl. 11, fig. 7).

Family DESMOCERATIDAE Zittel 1895
Subfamily PUZOSIINAE Spath 1922
Genus KITCHINITES Spath 1922

Kitchinites angolaensis sp. nov.
Plate 11, figs. 4-6

HOLotyPe. C. 52675 (Pl. 11, fig. 5), from 1 km. north of Egito, Angola.

MATERIAL. In addition to the holotype, 8 paratypes (C. 52676—-83) all from 1 km.
north of Egito, Angola.

DIMENSIONS:

C. 52675. At 64 mm.: 28-7, —, 16:5.
C. 52680. At 48-5 mm.: 22:0, —, II‘9.

DiaGnosis. Whorls moderately involute, inner whorls about one half concealed.
Whorl section compressed, with only slightly convex whorl sides, vertical umbilical
walls and an angled umbilical edge. On whorls up to 40 mm. diameter the ornament
consists of fine, slightly sigmoidal ribs which curve gently forwards on approaching
the venter; primary ribs cross whole side of whorl and intercalated secondaries
occur on ventral half only. Between 40 and 50 mm. diameter ribs gradually fade
on inner half of whorl leaving ribs near the venter only. At larger sizes ventral ribs
show marked increase in strength. 4 to 6 constrictions per whorl are present, but
poorly developed; on inner whorls they are of similar shape to the ribs but inclined
more strongly forwards and cut across the ribs; at larger sizes they are nearly
straight on side of whorl and curve slightly forwards on the venter. On outer surface

CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA 387

of shell, constrictions usually represented by or preceded by a collar on the venter.
Suture-lines not visible in detail.

REMARKS. These nine specimens were identified by Spath (1951: 8) as “Gen. nov.
(Kitchinites ?) sp. nov.”, but their generic characters are those of Kitchimites and
there are no adequate reasons for separating them. K. angolaensis is characterized
by fine sigmoidal ribs at small sizes, followed at larger sizes by smooth whorl sides
and considerably stronger ventral ribs. All the specimens are partly crushed making
estimation of the whorl thickness difficult. The most closely related species is
K. darwint (Steinmann 1895: 73, pl. 5, fig. 3) from the Quiriquina Beds of Chile,
which has the same smooth whorl sides, but differs in its larger umbilicus, thicker
whorls with more convex sides and its much stronger constrictions. The New
Zealand species K. brevicostata (Marshall 1926: 183, pl. 24, fig. 3, pl. 43, fig. 2) is also
close to K. angolaensis, but it has a larger umbilicus and nearly straight ribs that
do not fade on the side of the whorl. The type species Kvtchinites pondicherryanus
(Kossmat 1897: 40, pl. 6, fig. 6) has much stronger straight ribs throughout and
there is no evidence of the ribs fading on the sides of the whorl.

The genus Neopuzosia Matsumoto 1954, was proposed for the two Japanese
species, NV. japonica (Spath), the type species, and N. ishikawaz (Jimbo) (see Matsu-
moto 1954: 89-95), which have sigmoidal ribs, at least on the inner whorls, that are
strongly projected on the venter. The whorl is generally thicker and not so flattened
as in Kitchinites. Neopuzosia is now generally admitted as a subgenus of Kitchinites,
but K. brevicostata mentioned above is intermediate between the two in most of its
characters, and now K. angolaensis shows mixed rather than intermediate characters.
Its sigmoidal and fine ribs are like those of Neofuzosia, its compressed and flattened
whorls are like those of Kitchinites, while its smooth whorl sides at larger sizes are
shared only with K. darwint, usually placed in Kitchinites s.s. Neopuzosia is Santonian
and Lower Campanian in age, Kitchinites s.s. ranges from Campanian to Lower
Maastrichtian, and K. angolaensis is Upper Campanian. The horizon of K. darwimi
is not accurately known. Proposal of further generic names will confuse what is
probably a closely related group of species; K. angolaensis is referred here to
Kitchinites s.1., rather than to either subgenera which are of doubtful value.

Five species of Kitchinites s.1. from the Lower Campanian of Madagascar were
described by Collignon (1961: 55-58). All of them have considerably thicker whorls
than any of those listed above, but from their convex whorl sides and ribs projected
on the venter they would probably be referred to Neopuzosia rather than to
Kitchimites s.s. Of Collignon’s five specific names, K. busnardot, K. quadratus and
K. fascigerus (Collignon 1961: pl. 6, figs. 3, 4, pl. 23, fig. 3) represent a species with
coarse ribs, while K. flabelliformis and K. enayi (Collignon 1961: pl. 6, fig. 5, pl. 23,
fig. 2) represent a species with much finer ribbing. The ornament of the latter
species is hardly distinguishable from that of K. angolaensis, but the whorl thickness
of the Madagascan species must be about twice that of the Angolan species, even
allowing for the crushing in the latter. The Upper Turonian “Neopuzosia”’ matsumotot
figured by Collignon (1961: 54, pl. 23, fig. 1) appears to be a Mesopuzosza close to the
holotype of M. pacifica Matsumoto (1954: 82, pl. 15, fig. I).

388 CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA
Subfamily DESMOCERATINAE Zittel 1895
Genus DESMOPHYLLITES Spath 1929

Desmophyllites diphylloides (Forbes)
Plate 11, fig. 3

1846 Ammonites diphylloides Forbes: 105, pl. 8, fig. 8.

1953 Desmophyllites diphylloides (Forbes); Spath: 21, 49, pl. 2, figs. 5, 6.

1955 Desmophyllites diphylloides (Forbes); Matsumoto & Obata: 121, pl. 24, figs. 1-5, pl. 30,
fig. I.

1959b Desmophyllites diphylloides (Forbes); Matsumoto: 9, pl. 3, fig. 3.

1961 Desmophyllites diphylloides (Forbes) ; Collignon: 61-65, pl. 24, figs. 4, 5, pl. 25, figs. 1-8.

MATERIAL. 8 specimens, C. 41475 and C. 52661-67, from 1 km. north of Egito,
Angola.

DESCRIPTION. The eight specimens vary in size from 20 to 39 mm. diameter and
all are wholly septate, but only three are well preserved and free from lateral
crushing. Dimensions of these three are as follows:

C241473, “At 30mm): 1675, 12°5).2-7-
C. 52663. At 28-5 mm.: 15:0, 11°8, 2:5.
C. 52664. At 20 mm.: 10-7, 8:3, —.

All the specimens are unornamented except for constrictions on the internal
mould which are biconcave forwards on the sides of the whorl and are projected
forwards on the venter. There are 6 or 7 constrictions per whorl.

REMARKS. Full synonymy and description of this species have been given by
Matsumoto & Obata (1955), Matsumoto (1959b) and Collignon (1961). The best of
the Angolan specimens and the largest of Forbes’s three paratypes were figured by
Spath (1953, pl. 2, figs. 5, 6), and the lectotype is now figured (Pl. 11, fig. 3) for the
first time since Forbes’s original drawing. D. diphylloides shows a considerable
amount of variation in whorl dimensions, and strength and shape of the constrictions.
Collignon (1961: 61—65) has expressed this variation by dividing the Madagascan
specimens into four varieties; var. besairiei differs from the normal variety in having
the constrictions prolonged into a long narrow rostrum on the venter, var. imevmis
has greatly reduced constrictions which are sometimes almost absent, and var. lata
has a more compressed whorl shape, of which the dimensions listed by Collignon
(1961: 64) fall just below the lower limit of the species indicated on the whorl
height/breadth graph of Matsumoto & Obata (1955: 124). Undoubtedly these
varieties express the normal amount of variation that is now held to occur in many
species of ammonites. The Angolan specimens show about average characters of
the species and would be referred to the normal variety.

The species has a world-wide distribution in India, Japan, western north America,
Angola, Madagascar and south-east Africa. It has a relatively long range for an
ammonite species, which Matsumoto (1959): 11; 1959c: 70) gave as the whole of the
Campanian in Japan and extending up into the Lower Maastrichtian in some other

CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA 389

areas. Collignon (1961: 61-65), however, recorded many of his specimens from both
Lower and Upper Santonian, and it seems that a range from Lower Santonian to
Lower Maastrichtian must be admitted.

Subfamily HAUERICERATINAE Matsumoto 1938
Genus OIOPHYLLITES Spath 1953
Oiophyllites angolaensis Spath

1953 Otophyllites angolaensis Spath: 21, pl. 6, fig. 6.
HoLotyPe. C. 41476, the only specimen, from 1 km. north of Egito, Angola.

Remarks. The holotype of this species has been adequately figured by Spath
(1953: pl. 6, fig. 6), and consists of wholly septate and somewhat eroded inner whorls
of 22 mm. maximum diameter. No part of the shell is preserved and the surface of
the internal mould shows no trace of ornament. The whorl section is elliptical with
the greatest width near the umbilical edge, and the venter is smoothly rounded
with no keel, although this does not exclude the possibility of a keel occurring at
this size on the external surface of the shell. Dimensions: at 22 mm.: 10-0, 6:2, 5-7.

This specimen was referred to Ozop/yllites because of its resemblance to the five
Graham Land specimens of O. decipiens Spath (1953: 21, pl. 4, figs. 7, 8), the only
other species of the genus. The Graham Land specimens are even more poorly
preserved, but the shell is present in some places and shows that there is no keel on
the shell at 22 mm. diameter, and that sigmoidal striae cover the surface of the shell.
There are no constrictions. Matsumoto & Obata (1955: 136-137, text-fig. 6)
refigured two of the Graham Land specimens and suggested that the genus was an
offshoot of Hauericeras, and Collignon (1961: 21) has relegated Ozophyllites to a
subgenus of Hauericeras. The generic status and position of Ozophyllites cannot be
decided until much larger and better preserved material is available. The single
specimen of O. angolaensis may be merely the inner whorls of Hawuericeras as
suggested by Matsumoto & Obata (1955: 137), for larger specimens might reveal the
presence of a keel at a later growth stage. The Graham Land Ozophyllites were
associated with a fauna containing Maorites, a genus that can be accurately dated
as Lower Campanian in Madagascar.

Family PACHYDISCIDAE Spath 1922
Genus EUPACHYDISCUS Spath 1922
Eupachydiscus pseudogrossouvrei Collignon
Plate 12, figs. I, 4

1931 Pachydiscus grossouvrei Kossmat; Basse: 26, pl. 3, figs. 8, 9 (non pl. 2, figs. 16, 17).
1932 Parapachydiscus besairviei Basse; Collignon: 28, pl. 8, fig. 2.
1955 Eupachydiscus pseudogrossouvrei Collignon; 42, pl. 8, figs. I, 2.

MATERIAL. 7 specimens, C. 52668—74, from 1 km. north of Egito, Angola.

DESCRIPTION. All the specimens are crushed and distorted to some extent, but
in places the shell and ornament are well preserved. The largest is 105 mm. diameter

390 CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA

and has the best preserved whorl shape with the following approximate dimensions:
at 85 mm.: 40 (0-47), 40 (0:47), 20 (0:24). The whorl section is circular with smoothly
rounded umbilical walls. The ribs are radial and nearly straight on the sides of the
whorl, and curve forwards to form a slight projection on the venter. In most cases
long and short ribs alternate, the long ones starting at the umbilical seam and the
short ones starting some way up the side of the whorl. There are no tubercles on the
ribs at the umbilical edge. The largest specimen has 33 or 34 ribs on its outer whorl
at 105 mm. maximum diameter. Septa and suture-lines are poorly preserved and
are only seen in a few places, and the largest specimen is septate at its maximum
size.

REMARKS. Spath (1951: 8; 1953: 49) determined these specimens as “Eupachy-
discus sp. (cf. havadat, Jimbo sp.)’’. E. havadai (Jimbo) has been described at length
by Matsumoto (1954a: 281-287, pl. 8, fig. 2, pl. 9, pl. ro, figs. 1-3; 19590: 33-38)
from the Japanese type material and examples from California and Canada, and
some of the Canadian examples were separated as a slightly more compressed sub-
species. Madagascan specimens of E. havadai have been figured by Collignon (1938:
78, pl. 4, fig. 4; 1955: 44, pl. 9, fig. 1). All these examples differ from the Angolan
specimens in having thicker whorls, stronger ribs surmounted by tubercles at the
umbilical edge, and a constriction-like depression associated with some of the major
ribs. The Angolan specimens have straighter and less strong ribs and no tubercles
or constrictions, and they agree exactly with the species EF. pseudogrossouvrei from
Madagascar. The age of this species is known to be the upper part of the Middle
Campanian in Madagascar (Collignon 1955: 88-89; Besairie & Collignon 1960: 77-78).
Another Madagascan specimen was separated by Collignon (1955: 43, pl. 8, fig. 2)
as var. undulatocostata on account of its slightly closer and gently curved ribs. The
single specimen on which this variety was founded occurs somewhat lower in the
Middle Campanian than the normal form, and if it is genuinely separable, then the
Angolan specimens agree with the normal variety with straight ribs.

Most other species of Eupachydiscus (for lists see Collignon 1955: 79) have tubercles
or bullae at the umbilical edge and stronger and more widely spaced ribs, and the
only one which is close to E. pseudogrossouvrei is E. launayi (Grossouvre 1894: 184,
pl. 19). In France E. launayi is known only from the single type specimen from the
Lower Campanian, but 15-20 specimens have been described by Collignon (1938:
60, pl. 1, fig. 2; 1955: 36-38, pl. 5, fig. 1) from the Lower Campanian of Madagascar,
well below E. pseudogrossouvrei in the Middle Campanian (Collignon 1955: 89;
Besairie & Collignon 1960: 78). E. launayi differs from EF. pseudogrossouvrei only
marginally in having slightly higher and thicker whorls and feeble tubercles on the
ribs at the umbilical edge. Specimens very close to E. launayi were described by
Collignon (1955: 39, pl. 6, fig. 2) from a higher level in Madagascar and overlapping
with the horizon of E. pseudogrossouvret. The ribs in this form are more dense, the
tubercles are larger and the periodic larger ribs appear at an earlier stage than in
E. launayt, so its resemblance to E. pseudogrossouvrei is less close.

CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA 391

Family PLACENTICERATIDAE Hyatt 1900
Genus HOPLITOPLACENTICERAS Paulcke 1906

TypE species. Hoplites plasticus Paulcke 1906 (ICZN Opinion 554); the
lectotype of the species is Paulcke 1906, pl. 13, figs. 1, ra-d.

The specific classification of Hoplitoplacenticeras is in a state of confusion owing to
the apparently large amount of variation in a single species, and the nine rather
poorly preserved Angolan specimens do not clarify any of the difficulties.
Hoplitoplacenticeras is, however, one of the most important genera for dating the
beds at Egito, and it will be useful to outline the basis on which this genus has
been accurately dated.

Evidence relating to the position of Hoplitoplacenticeras in the classical sections
of France and Germany was summarized by Grossouvre (1901: 801-803, table 35),
who found that with the exception of H. lafresnayanum (d’Orbigny) (known from
only one, or perhaps a very few, specimens from the Calcaire a Baculites of Manche
that contains other ammonites characteristic of the Neubergicus Zone, Lower
Maastrichtian), all the other species of the genus characterize a zone at the top of
the Campanian, which was named after the most typical species, H. vari (Schliiter).
More recent work by Jeletzky (1951: 18, 74) has shown that the Upper Campanian
is divisible into two zones, of which the lower one is the zone of H. vavi and contains
all the species of Hoplitoplacenticeras.

Besairie & Collignon (1960: 74-80) have summarized the accurate stratigraphical
work of Hourcq (1950: 64-85) and earlier workers in Madagascar and have shown
that the few specimens of Hoplitoplacenticeras in that island are confined to the
H. vari Zone, taken there as comprising the whole of the Upper Campanian. Direct
evidence as to the age of the H. plasticum fauna in Patagonia is poor, for the only
associated forms at the same locality, Cerro Cazador f (Paulcke 1906: 235-240),
are several long-ranging species of Tetragonitidae, and Psewdokossmaticeras paulcki
Collignon (1955a: 44) which might be of Upper Campanian age, although most
species of the genus are Maastrichtian. Hoplitoplacenticeras vancouverense occurs
in the Cedar District Formation in British Columbia, which can be dated fairly
accurately as Upper Campanian (Usher 1952: 38-39). A specimen of Hoplitoplacenti-
ceras found in Wyoming (Cobban 1963: C60) has allowed one point in the established
zonal sequence of baculitids in the western interior of the United States to be
correlated against the standard Campanian sequence of Europe.

Hoplitoplacenticeras cf. marroti (Coquand)
late i2 howe bl ah fie. 3

1859 Ammonites marroti Coquand; 995.
Cf. 1867 Ammonites coesfieldensis Schliiter: 14, pl. I, figs. 2, 3, 5, non figs. I, 4.
Cf. 1867 Ammonites costulosus Schliiter: 17, pl. 2, fig. 1, non figs. 2-4.
Cf. 1872 Ammonites striatocostatus Schliiter: 65, pl. 20, figs. 1-4.
Cf. 1872a Ammonites vari Schliiter: 92.

392 CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA

Cf. 1876 Ammonites vari Schliiter; Schliiter: 160.
1894 Ammonites vari Schliiter var. marroti Coquand; Grossouvre: 118, pl. 8, fig. 3, pl. 9,
figs. 2, 3.
1898 Hoplites vari var. marroti (Coquand) ; Choffat: 80, pl. 20, figs. 1-5.
Cf. 1906 Hoplitoplacenticeras plasticum costatum Paulcke: 34, pl. 11, fig. 2, pl. 12, figs. 1-3,
Goll, 305}, 1st, B.
1925 Hoplitoplacenticeras vari (Schliiter); Diener: 178.
1929 Hoplites cf. vari (Schliiter); Barrabé: 181, pl. 9, figs. 11-13.
?1931 Hoplites vari (Schliiter) ; Basse: 35, pl. 5, figs. 1-3, pl. 12, fig. 2, pl. 13, fig. 1.
1947 Hoplitoplacenticeras vari (Schliter); Chavan: 129, pl. 2, fig. 1.
1963 Hoplitoplacenticeras marroti (Coquand) Young: 63, pl. 2, figs. 5, 15, 17, pl. 17, figs. 3, 4,
PlZontesN2 3) Plaza hoSw ANDi i mt cel

MATERIAL. Two specimens, C.52684-85, from 1 km. north of Egito, Angola.

DESCRIPTION. Both specimens consist of about half a single whorl, roughly
60 mm. and 45 mm. diameter, which are rather poorly preserved and slightly
distorted. The whorl breadth is about two-thirds of the height and the whorl section
is angled at the tubercles. Long, slightly sigmoidal primary ribs alternate with
less prominent secondary ribs which commence at the middle of the side of the
whorl. The ribs cross the venter but are much reduced between the ventral tubercles.
There are small umbilical tubercles, small mid-lateral tubercles, moderate, clavate
lower ventro-lateral tubercles, and small upper ventro-lateral tubercles.

REMARKS. The holotype of H. marroti was figured by Grossouvre (1894, pl. 8,
fig. 3), and this specific name has priority over H. vari Schliter (1872a) which was
substituted by Schliiter for his Ammonites striatocostatus Schliter (1872:65) already
preoccupied by Meneghini (1856). The type specimens of H. vari are therefore
those described and figured by Schliiter (1872: 65, pl. 20, figs. 1-4.) Other specimens
referred to H. vari by Schliiter are those listed as Ammonites coesfieldensis and
A. costulosus in the synonymy above, but the proper interpretation of H. vavi must
await a full revision of Schliiter’s types and further topotype material. Judging
from the best of Schliiter’s figured specimens (1872, pl. 20, figs. 1, 2), H. vari is
probably conspecific with H. marroti, but it may be found that a varietal distinction,
H. marroti var. vari, is necessary. H. praematura (Imkeller 1901: 58, fig. 1) from the
northern Alps may be another variety of H. marroti, but from its apparently early
loss of tubercles full specific distinction may be advisable.

The two Angolan specimens agree well with the holotype of H. marroti, although
they differ in the development of a small mid-lateral tubercle, and the lower ventro-
lateral tubercle is as large as, or larger than, the upper ventro-lateral tubercle. Their
fragmentary nature and preservation does not allow further comparisons to be
made. The Portuguese examples figured by Choffat, the Madagascan examples
figured by Barrabé, the Palestine example figured by Chavan and the Texas examples
figured by Young, all listed in the synonymy above, conform more-or-less closely
with H. marroti. Further Madagascan examples figured by Basse (1931: 35, pl. 5,
figs. I-3) are more compressed and have less prominent ribs. The other European
species of Hoplitoplacenticeras differ markedly: H. dolbergense (Schliiter 1876: 159,
pl. 44, figs. 1-4) is the closest, but its ventro-lateral tubercles are larger and the

CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA 393

ribs are looped to them; H. coesfieldensis (Schliiter 1867: 14, pl. I, figs. I, 4 only),
and H. lemfordense (Schliiter 1876: 160, pl. 44, figs. 8, 9) have dense, well marked
ribs; and H. lafresnayanum (d’Orbigny 1842: 326, pl. 97, figs. 3-5; Grossouvre
1894, pl. 23, fig. 4) is a Lower Maastrichtian species that has bold and strongly
inclined ribs. Amongst the Patagonian forms of H. plasticum, H. plasticum costatum
Paulcke (see synonymy) agrees with the Angolan specimens in strength of ribs and
tubercles, but its ribs are almost straight, not sigmoidal.

Hoplitoplacenticeras cf. costulosum (Schliiter)
Platesrs: fige2

1867 Ammonites costulosus Schliiter: 17, pl. 2, figs. 2-4, non fig. I.

1872 Ammonites costulosus Schliiter; Schliiter: 66, pl. 20, figs. 5, 6.

1906 Hoplitoplacenticeras plasticum laeve Paulcke: 45, pl. 14, figs. 3, 4, pl. 15, figs. 2, 3.

1931 Hoplites (Hoplitoplacenticeras) plasticum Paulcke; Basse: 36, pl. 4, figs. 5, 6, pl. 12, fig. 3.

MATERIAL. Three specimens, C.52686-88, from 1 km. north of Egito, Angola.

DeEscriPTION. The three specimens are 32 mm., 27 mm. and 22 mm. diameter
respectively, and the outer whorl of the largest is fairly well preserved. The whorl
shape is compressed, with almost flat whorl sides tapering towards a narrow flat
venter. The sigmoidal ribs are of low relief, but are broad and flat, and the inter-
spaces are narrow. The umbilical tubercles are only small raised portions of the ribs.
The lower ventro-lateral tubercles are clavate ends to the ribs, and the upper ventro-
lateral tubercles are smaller and are situated on the venter. There are no mid-lateral
tubercles.

Remarks. The largest Angolan specimen compares well with the most strongly
ribbed of those figured by Schliiter (1867, pl. 2, fig. 2) and with the smoothest
specimen figured by Paulcke (1906 pl. 15, fig. 2), except that both Schliiter’s and
Paulcke’s figures show only one ventro-lateral tubercle, while the Angolan specimens
have both upper and lower ventro-lateral tubercles close together. Schliiter (1867,
pl. 2, figs. 3, 4) also figured specimens in which the ribs are striate, and Paulcke
(1906, pl. 15, fig. 3) figured one which develops prominent umbilical tubercles. The
relationship of Schliiter’s and Paulcke’s species cannot be deduced until their respec-
tive ranges of variation are worked out, and further specimens figured photographi-
cally to show the type of ventro-lateral tubercles developed. Two Madagascan
specimens figured by Basse (1931, pl. 4, figs. 5, 6) are similar to the Angolan speci-
mens. H. vancouverense (Meek 1976a: 370, pl. 6, fig. 1; Usher 1952: 93, pl. 25,
figs. I, 2) also has reduced ribs at all growth stages, but it differs in its thicker whorls
and much larger vertro-lateral tubercles. H. lafresnayanum (d’Orbigny) (Gros-
souvre: 1894: 121, pl. 23, fig. 4) has a similar pattern of tubercles, but it has con-
siderably stronger ribs.

Hoplitoplacenticeras spp. indet.

MATERIAL. Four specimens, C.52689-92, from 1 km. north of Egito, Angola.

394 CRETACEOUS AMMONITES AND -NAUTILOIDS FROM ANGOLA

DescriPTION. Three of the specimens (C.52689-91) are the inner whorls of an
indeterminate species of this genus. The fourth specimen (C.52692) differs markedly
from any hitherto described species. It is 26 mm. diameter and the preservation is
sufficiently good to see that the whorl is very broad, with a height to breadth ratio
of about 0-7, there are large tubercles or spines on the side of the whorl, and the wide,
flat venter has four rows of small tubercles, the inner pair of rows bounding a well
marked mid-ventral groove. The pattern of tubercles is similar to that of one of
Paulcke’s specimens (1906, pl. 13, fig. 2), but the wide, flat, centrally grooved venter
is more exaggerated and the maximum size of the specimen is only 26 mm. diameter.

Family SPHENODISCIDAE Hyatt 1900

The type of subdivision of the first lateral saddle of the suture-line has been
regarded by most workers as the most important generic character in this family. A
primary bifurcation of the first lateral saddle has always been taken as distinctly
different from a primary trifurcation of the saddle. Within the two groups thus
formed genera have been separated according to the degree of indentation of the
saddles and to major differences in ornament and whorl shape. The nomenclature
is complicated by a considerable number of ammonites having a primary bifurcation
of the first lateral saddle followed by another bifurcation of the ventral half of the
saddle, the resulting pattern of “‘secondary trifurcation” remaining clear throughout
growth. Such forms have been variously referred to the nearest existing genera
or made the basis of new generic names. The classifications adopted by Picard
(1929: 452-453), Olsson (1944: 108-112), Hourcq (1949: 113-115) and Basse (1954:
866-869) were based on these lines, where primary consideration was given to the
subdivision of the first lateral saddle.

Wright (1957: L437) was the first to point out that details of suture-lines can be
misleading in this family, and the classification which he adopted showed a more
balanced appraisal of all the characters. With the discovery of the Angolan speci-
mens described below which appeared to be typical Manambolites, except that the
first lateral saddle showed primary trifurcation, not bifurcation, the possibility that
this character was not of generic value, and perhaps not even of specific value,
required investigation. The characters of the species referred to all the sphenodiscid
genera can be summarized as follows (see Wright 1957: L437 for details of nomen-
clature) :

1. Luibycoceras Hyatt 1900. All saddles entire. First lateral saddle shows either
bifurcation or secondary trifurcation. All species are ornamented, except L. acuto-
dorsatum and the unfigured and undescribed species L. chargense Blanckenhorn
(1900: 45) which are smooth. The species showing secondary trifurcation is L.
acutodorsatum (Noetling 1897: 76, pl. 21, fig. 3) which has always been referred
before to Sphenodiscus, but all its saddles are entire, wholly unlike even the simplest
suture-line of Sphenodiscus. Paciceras Olsson (1944: II0-I12) is a synonym, and it
shows the beginnings of a secondary bifurcation of the outer half of the bifid first
lateral saddle.

CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA 395

2. Indoceras Noetling 1897. Like Libycoceras, with first lateral saddle bifid,
but smooth and with rounded venter at least on the two outer whorls.

3. Manambolites Hourcq 1949. All parts of the first lateral saddle are indented
and sometimes the second lateral saddle also. Remaining saddles entire. First
lateral saddles either bifid or trifid, and some bifid examples have a tendency to a
second bifurcation of the outer half. Smooth or feebly ornamented. The trifid
species is the Angolan form described below. A considerable amount of variation
in suture-line details was shown to exist by Hourcq (1949: 112, figs. 21, 22).
Mzezzemceras Basse (1954: 868, pl. 17, fig. 2) is a synonym.

4. Coahwilites Bose 1927. Suture-lines generally like those of the simpler ones of
Sphenodiscus and show the same narrow-necked, kidney shaped saddles. Of the
three species described by Bése (1927: 279-293), the type species has a bifid first
lateral saddle, while in the other two species this saddle is bifid then the outer half
is bifid again. It differs from Sphenodiscus by its well marked ribs and tubercles,
and rounded or flat venter at some stage. Daradiceras Sornay & Tessier 1949, is an
extreme development of Coahuilites showing large ribs and tubercles, and might be
considered a subgenus of Coahuilites.

5. Sphenodiscus Meek 1871. All saddles of the suture-line usually indented,
but some or all of the auxiliary saddles may be entire. Saddles narrow-necked
and kidney shaped in complicated suture-lines. First lateral saddle usually trifid,
but examples are known where this saddle is primarily bifid, with the outer half bifid
again. One series of such examples were made the basis of the genus Austrospheno-
discus Olsson (1944: 108-110), and the Texan species S. plewrisepta (Conrad) has a
suture-line in which the range of variation includes both trifid and bifid examples—
the suture-line of an example which is clearly bifid, with the outer half again bifid,
is shown in Text-fig. 22. Smooth or only weakly ornamented.

The alternative to admitting this amount of variation in the suture-lines of
sphenodiscid genera is the further multiplication of generic names by creating new
genera for Libycoceras acutodorsatum and the Angolan species described below,
according generic status to Austrosphenodiscus, and possibly creating a new genus
or subgenus for the specimen of S. flewrisepta referred to above. Such a purely
morphological classification would obscure relationships, and tend to separate into
different genera even conspecific specimens.

The age of spenodiscid genera by dating against associated ammonites of zonal
value is not as well established as is often assumed, for the mere presence of any
sphenodiscid has too often been taken as an indication of a Maastrichtian age. The
type species of Manambolites occurs in the Middle Campanian in Madagascar and at
one locality it occurs as low as the base of the Middle Campanian (Hourcq 1949:
113; Besairie & Collignon 1960: 77-79). The other species of Manambolites are
probably Upper Campanian only. Evidence that the type species of Libycoceras
and the associated L. chargense Blanckenhorn are Upper Campanian in age in north
Africa and the Middle East was presented by Reiss (1962); they occur in the Zone
of Bostrychoceras polyplocum, taken as the top of the Upper Campanian. No other

396 CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA

species of Libycoceras (including Paciceras) are accurately dated. Indoceras is not
accurately dated against associated ammonites. The earliest species of Coahuilites
are probably Upper Campanian, but later ones are undoubtedly Maastrichtian.
Sphenodiscus is well dated at many localities as Maastrichtian (see pp. 403-404), and
it is not known in the Upper Campanian. In the present state of knowledge
derivation of the whole family from Ewulophoceras at the end of the Lower
Campanian is the most likely phylogeny.

Genus MANAMBOLITES Hourcq 1949
Manambolites dandensis sp. nov.
Plate 12, fig: 2, Pl. 13, fig. 1; Text-figs, 18-21

1953 Gen. nov. (“Sphenodiscus’’) sp. nov. aff. Manambolites spatht, Picard sp.; Spath: 49, pl. 3,
fig. 6.

Horotyee. C. 41474 (Pl. 13, fig. 1), from Barra do Dande, Angola.

MATERIAL. In addition to the holotype, C. 52734, C. 52736 (paratypes), and
C. 52735, from Barra do Dande, Angola.

D1acGnosis. Smooth or very feebly ornamented species, of which the first lateral
saddle of the suture-line is divided into three by two adventitious lobes. The three
parts of the first lateral saddle are slightly indented, all other saddles entire.

Description. The holotype is an adult specimen measuring 134 mm. diameter
at the nearly complete mouth border. The adult body chamber occupies slightly
less than half a whorl and has extensively modified features. The whorl height is
markedly lowered away from the true spiral; from the beginning of the body chamber
the venter alters rapidly from sharp to evenly rounded, and near the mouth border
becomes almost tabulate; and near the mouth border the thickness of the dorsal
half of the whorl is greatly contracted. The mouth border curves gently forwards
on approaching the venter, but no part of it is preserved on the venter itself. The
half whorl before the body chamber is preserved complete with the shell; the umbili-
cus is a pin hole, the whorl shape is oxycone with a sharp venter, and the evenly
convex sides of the whorl are interrupted just before the venter by a slight rounded
ridge. Sinuous growth striae cover the shell surface, and there are very low radial
undulations on the outer half of the whorl side which reach as far as the low spiral
ridge; at the middle of the side of the whorl there are very small radially elongated
raised portions on each undulation. The final suture-line is completely exposed
together with parts of the two previous ones, and these appear to be crowded though
they cannot be compared with earlier ones. The first lateral saddle is divided into
three by two adventitious lobes, the outer lobe is smaller than the inner one but the
saddle as a whole is clearly trifid rather than bifid, and the three saddles thus formed
are moderately indented. The second lateral saddle and the seven auxiliary saddles
are entire. The last three auxiliary saddles just before the umbilicus are markedly
retracted.

CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA 397

The two paratypes are wholly septate specimens. The larger one (PI. 12, fig. 2)
has a maximum diameter of 75 mm., and at this size the last three suture-lines are
approximated. This is considerably smaller than the 102 mm. diameter at which
the final suture-lines occur in the holotype. This specimen has very low and rudi-
mentary tubercles at the middle of the whorl side from which equally low undula-
tions run to a very slight ridge at the side of the venter. The venter itself is sharpened
to a knife edge. The smaller paratype consists of only one-third of a whorl of about
50 mm. diameter. In both paratypes the suture-lines (Text-figs. 18, 19) have the
same basic pattern as in the holotype, and in the earliest suture-line visible in the
smaller paratype at 38 mm. diameter, the first lateral saddle is clearly trifid. In
almost every case the three parts of the first lateral saddle are indented, and all the
other saddles are entire.

Remarks. Three of the specimens described here formed the basis of Spath’s
(1951: 9, 1953: 49) three determinations—“‘Manambolites sp. nov. aff. M. spathi
(Picard)” (also “Gen. nov. (“Spenodiscus’’) sp. nov.” in 1953: 49, pl. 3, fig. 6),
“Libycoceras angolaense Haughton” and “‘Libycoceras sp. nov.’’. There is a fourth
specimen in the collection, C. 52735, which is a fragment of part of a whorl of roughly
120 mm. diameter, and has the ventral parts of six suture-lines (Text-fig. 21). The
last three of these are noticeably closer together and they may be the adult suture-
lines. Those parts of the suture-line that can be seen agree with the present species,
but the specimen is broken before the first lateral saddle is reached in each case, so
the specimen can only be identified as Manambolites cf. dandensis.

The most closely comparable species is Manambolites piveteaui Hourcq (1949: III,
pl. 3, fig. 1) from Madagascar, which has the same adult body chamber modifications,
but differs in its clearly bifid first lateral saddle. The suture-line of this species shows
considerable variation in details as can be seen from Hourcq’s figures (1949: 112,
figs. 21, 22), but the basic pattern of a first lateral saddle is constant. It is from the
Middle Campanian of Madagascar (Besairie & Collignon 1960: 77~79). The only
other described species of Manambolites are M. spathi (Picard 1929: 449, fig. Io)
from the Upper Campanian of Palestine, which has the characteristic suture-line
with a bifid first lateral saddle, but is otherwise poorly preserved, and M. pervinguiert
(Basse 1954: 866, pl. 17, fig. 2) from Tunisia (probably from the Upper Campanian),
which is very close to M. piveteaw, has the same bifid first lateral saddle, but may
have slightly stronger ornament. M. pervinquiert was made the type species of
Mzezzemceras Basse (1954: 868) used as a subgenus of Coahwilites, but its relation-
ships to Manambolites are so close (it may even be conspecific with M. piveteam,
the type species of the genus) that it must be considered a synonym of that genus.

“Manambolites” ricensis Young (1963: 127, figs. 8/, 9m, p, 11h, pl. 2, figs. 14, 16,
19, pl. 72, fig. 4, pl. 74, fig. 2) is, as was pointed out by its author, an enigma. It is
undoubtedly from the top of the Campanian in Texas, but it has a suture-line like
Paralenticeras or Eulophoceras. The trifid first lateral saddle and bifid second lateral
saddle, of which all parts are well frilled (Young 1963: figs. 8/, gm), are distinctly
like those of Paralenticeras of the Upper Coniacian and Lower Santonian, and resemble
to some extent those of Eulophoceras which ranges as high as the Lower Campanian,

398 CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA

PEER, OOO ORR

iS)
i)
Sey,

Fics. 18-23. Suture-lines of Sphenodiscidae. 18-21. Manambolites dandensis sp. nov.
Upper Campanian, Barra do Dande, Angola. Fig. 18, Paratype, C. 52736, at 26 mm.
whorl height, x2. Fig. 19, Paratype, C. 52734, at 42 mm. whorl height, x 1-6. Fig. 20,
Holotype, C. 41474, last suture-lines at 63 mm. whorl height, x 1-1. Fig. 21, First lateral
saddle of C. 52735, at approx. 75 mm. whorl height, x1-5. Fig. 22. Sphenodiscus pleuri-
septa (Conrad). Maastrichtian, Upper Escondido Formation, Honda Creek—Rock
Crossing, Medina County, Texas. C. 53965, at 68 mm. whorl height, x1. Fig. 23.
Sphenodiscus sp. indet. Maastrichtian, Barra do Dande, Angola. C. 52733, at 108 mm.
whorl height. x tI-I.

The most complicated suture-line of Manambolites (Hourcq 1949: 112, fig. 22-7) is
considerably different.

The only Sphenodiscid ammonites previously recorded from Angola are the three
specimens of Libycoceras angolaense Haughton (1925: 269-270, pl. 14, figs. I-5).
These have bifid first lateral saddles in every case, all their saddles are entire, and
their ornament is characteristic of the genus Libycoceras.

Genus SPHENODISCUS Meek 1871
Sphenodiscus sp. indet.
Text-fig. 23
MATERIAL. One specimen, C. 52733, from Barra do Dande, Angola.

ReEMARKS. The specimen is an internal mould and consists of one quarter of a
wholly septate whorl preserved on one side only. Its maximum whorl height is

CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA 399

125 mm., which indicates a diameter of about 200 mm. The whorl section is oxycone
and highly compressed, and there is no ornament on the internal mould. The suture-
line (Text-fig. 23) has a trifid first lateral saddle, and greatly indented parts to the
first and second lateral saddles. There are six auxiliary saddles of which the three
ventral ones are slightly indented.

Few species of Sphenodiscus have suture-lines as complicated as that of the present
fragment. The large specimen of S. Jobatus (Tuomey) figured by Hyatt (1903: 66, pl. 7)
is closely comparable in most characters, but its whorl section is much less compressed
and its saddle endings differ in detail. Several other north American specimens
figured by Hyatt (1903, pl. 6, figs. 3, 4, pl. 8, figs. 3-7, pl. 9, figs. 7-10) differ only
in details of the saddle indentations and their number of auxiliary saddles. The
suture-line of S. szva (Forbes 1846: 110, pl. 7, fig. 6; Stoliczka 1865: 59, pl. 33, fig. 3;
Kossmat 1895: 177, pl. 22, fig. 2) is very complicated at the largest known diameter
of 65 mm., and larger specimens of this species might be closely comparable with the
Angolan specimen.

Family NAUTILIDAE dOrbigny 1840

Genus EUTREPHOCERAS Hyatt 1894
Eutrephoceras simile Spath

1909 Nautilus blanfordianus Kilian & Reboul: 8, pl. 1, figs. 1, 2.
1953 LEutrephoceras simile Spath: 40, pl. 12, fig. 4, pl. 13, figs. 1-5, 7.
1950 Eutvephoceras egitoense Miller & Carpenter: 34, pl. I, figs. 1-4.

MATERIAL. Nine specimens, C. 41480 and C. 52710-17, from 1 km. north of
Egito, Angola.

REMARKS. Sixteen specimens from the same horizon and locality as the present
collection were described as EF. egitoense by Miller & Carpenter (1956: 34, pl. I,
figs. 1-4). One specimen from the present collection (C. 41480) was figured as
E. aff. simile by Spath (1953, pl. 13, fig. 7). From Miller & Carpenter’s description
and figures, and from a comparison of the new Angolan material with the Graham
Land material, itisclear that the Angolan specimens are EF. simile, and that E. egitoense
isasynonym. A specimen from Snow Hill Island, Graham Land, obtained after Spath’s
original description shows the sharp reticulate pattern of transverse and longitudinal
striae in the young growth stages (20-30 mm.) much better than in any of the originals
available to Spath. The transverse striae have a slight sinus in the middle of the
venter. The Angolan specimens do not differ in any way from the Graham Land
examples—they have a whorl height/breadth ratio of about 0-70 at 50 mm. diameter,
reticulate striae on the inner whorls, an approximately central siphuncle on the
inner whorls that becomes more ventral at larger sizes, and a straight, radial external
suture-line that is retracted at the edge of the umbilicus, all characters typical of
E. simile. As with the collection described by Miller & Carpenter (1956) the specimens
are rather poorly preserved and distorted, preserved in a light brown calcareous
sandstone, and they do not add anything to the description of those authors.

400 CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA
IV AGES OF THE FAUNAS DESCRIBED

(a) Douvilleiceras fauna of Dombe Grande.

The nine specimens of Dowvilleiceras mammuillatum (Schlotheim)? var. aequinodum
(Quenstedt) and D. orbignyi: Hyatt from Dombe Grande, are all that now remain of
more than 50 examples of Dowvilleiceras collected in 1930 and 1931 by Alexandre
Borges from various localities south-west of Benguela. Borges stated (im litt. to
Spath) that they all came from beds above the Pholadomya beds. In fact Borges
had searched the Pholadomya beds for ammonites for several years and had found
none. Recent work on the stratigraphy of the area south-west of Benguela by Neto
(1960: 89-99; 1961: 65-77) has confirmed the placing of these Dowvilleiceras in
beds above the Pholadomya pleuromyaefornus beds, and in fact a formation character-
ized by Nerinea (and some indeterminate ammonites) and reaching 400 metres in
thickness comes between the Pholadomya beds below and the ‘“‘Acanthoceras”’
(i.e. Douvilleiceras) beds above. Therefore Choffat’s (1888: 20, 71) placing of one of
his two specimens of Dowvilleiceras in the Pholadomya beds is probably incorrect
(Mouta & O’Donnell 1933: 58-61).

The age of all the Douvilleiceras seen so far is Mammillatum Zone, Lower Albian.
This, not Upper Albian, is the age of the ““Acanthoceras’’ Formation of Neto (1960:

95; 1961: 69, 74).
(b) Neokentroceras fauna of Praia do Jombo.

The Jombo beach lies in the Benguela basin just south-west of the mouth of the
Hanha (=Cubal) River and 16 km. north-east of Lobito. This is the same locality
as that (‘“‘shore at landing place near Hanha’’) from which most of Spath’s original
Neokentroceras came, and the specimens described by Haas (1942) came from a cliff
on the bank of the same river near Hanha. Henrique O’Donnell, who collected the
present specimens, said (zt litt. to Spath) that they came from beds in the lower
part of the Upper Albian formation. This is the only direct evidence for their
stratigraphical position; but combined with the morphological evidence that they
are probably an end-form development of Hysteroceras, it is fairly certain that their
age is low in the Upper Albian. This is the age of the lowest dateable part of the
“Pervinquerta”’ Formation of Neto (1960: 95; 1961: 69, 75), and higher parts of this
formation which contain the abundant fauna of Mortoniceras, Elobiceras, Puzosia
and Hamitidae are higher in the Upper Albian. The Middle Albian is either repre-
sented by a disconformity between the ““Acanthoceras” and “‘Pervinquieria” Forma-
tions, or, more likely, is represented by beds in these formations that do not contain
ammonites. The full fauna of Neokentroceras at Praia do Jombo consists of the
following species; N. curvicornu Spath, N. singulare Haas, N. subtuberculatum
Spath, N. trituberculatum sp. nov., N. pseudovaricosum Spath and N. crassicostatum
sp. nov.

north of Egito. It is exposed for 1200 m. along the shore, but the variable width of
the beds never exceeds 300 m. The formation consists of horizontal marly limestones

CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA 401

and coarse sandstones with unfossiliferous clays below, and is 40 m. thick. It rests
unconformably on Upper Albian beds containing Stoliczkaia dispar in the upper
part. According to O’Donnell (7 litt. to Spath) this outlier is the only one that
contains ammonites amongst several similar ones (but with more sandstone and
conglomerate) that occur between Egito and Lobito. The full cephalopod fauna
from Egito is:

Anagaudryceras nikobokense Collignon

Gaudryceras varagurense Kossmat

Didymoceras subtuberculatum sp. nov.

Polyptychoceras pseudogaultianum (Yokoyama)

Kitchimites angolaense sp. nov.

Desmophyllites diphylloides (Forbes)

Otophyllites angolaense Spath

Eupachydiscus pseudogrossouvrei Collignon

Hoplitoplacenticeras cf. marroti (Coquand)

H. cf. costuloswm (Schliiter)

H. spp. indet.

Eutrephoceras simile Spath

Tetragonites sp. indet.

All the above species except the last one have been described in the systematic
part of this paper. Tetrvagonites sp. indet. is represented by only one specimen that is
poorly preserved and not specifically determinable. The presence of Hoplitoplacenti-
ceras is sufficient to place the fauna in the zone characterized by this genus (Hoplito-
placenticeras vari Zone) in the Upper Campanian. If the Zone of Bostrychoceras
polyplocum is also put into the Upper Campanian (see discussion of Barra do Dande
fauna below) rather than in the Maastrichtian, then the Egito fauna is referable to
the lower half of the Upper Campanian. This does not clash with Spath’s (1951: 8;
1953: 49) dating of the fauna as the “‘very top of the Campanian’’, because Spath was
following Haug’s classification where the Polyplocum Zone was placed as the basal
zone of the Maastrichtian. The second view expressed by Spath in the same papers,
that the Egito fauna “‘could equally well be considered to be basal Maastrichtian’’,
reflected his suspicions that Hoplitoplacenticeras might not be confined to the zone
that it is said to characterize (Spath 1953: 52) and also his desire to lower the base
of the Maastrichtian still further so that it included the Vari Zone as well. But
Spath’s fears that Hoplitoplacenticeras might occur outside the Vari Zone in Mada-
gascar are not justified, for apart from the anomalous species H. lafresnayanum, the
genus is a good zonal indicator (see p. 391 above). Wherever the Campanian—
Maastrichtian boundary is placed, the Egito fauna can be definitely referred to the
Vari Zone.

No indication was given by O’Donnell that any part of the ammonite fauna was
collected from any particular bed at Egito. The fauna can only be considered as a
single unit, and none of the ammonites other than Hoplitoplacenticeras conflicts with
this placing of the assemblage in a single zone—the Vari Zone of the Upper Cam-
panian. Eupachydiscus pseudogrossouvrer occurs in the upper half of the Middle

402 CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA

Campanian in Madagascar, in the Zone of Delawarella subdelawarensis (Besairie &
Collignon 1960: 77). This does not conflict with its presence in the Vari Zone in
Angola, especially as Hoplitoplacenticeras is not common in Madagascar and its full
range there might not yet be known. Kztchinites angolaense is not accurately
dateable against any other species of the same genus, which are generally of Cam-
panian or Lower Maastrichtian age. Desmophyllites diphylloides has a long range
from the Lower Santonian to the Lower Maastrichtian, while Oiophyllites angolaensis
can only be compared with O. decipiens which occurs in the Lower and ? Middle
Campanian in Antarctica. Of the three lytoceratid species, Anagaudryceras
mikobokense occurs in the Lower Maastrichtian in Madagascar and the Lower
Maastrichtian or top of the Campanian in California, Gaudryceras varagurense occurs
in the Santonian in India and has been recorded from the Santonian and Campanian
of many other localities, and the Tetvagonites sp. indet. cannot be accurately dated.
Such lytoceratids tend to be relatively long ranging and the presence of all three in
the Upper Campanian does not clash with any previous records. The two hetero-
morph ammonites in the Egito fauna cannot be used for accurate dating : Didymoceras
subtuberculatum is a new species not clearly related to any other species of the genus
that occur in the Campanian or Maastrichtian; Polyptychoceras pseudogaultianum
occurs in the Santonian and Campanian in Japan, and a closely related species occurs
in the Upper Campanian of British Columbia.

(d) The Barra do Dande fauna

The Barra do Dande ammonites collected by Henrique O’Donnell and Beeby
Thompson consist of the following species:

Neophylloceras ultimum Spath
Baculites sp. indet.

Didymoceras cf. hornbyense (Whiteaves)
D. cf. angolaense (Haughton)
Nostoceras hyatti Stephenson

N. cf. kernense (Anderson)

N. rotundum sp. nov.

N. helicinum (Shumard)

N. (2?) obtusum sp. nov.

Solenoceras sp. indet.

Polyptychoceras pseudogaultianum (Yokoyama)
Manambolites dandensis sp. indet.
Sphenodiscus sp. indet.

All the above species, except Solenoceras and Baculites, have been described in
the systematic part of this work. Solenoceras is represented by one very small
fragment that has fine, slightly oblique ribs and two rows of small tubercles on the
venter. It is not worth describing and may belong to either S. binodosa (Haughton
1925: 278) or S. bembense Haas (1943: II, figs. 4, 14) from Angola. There is one short
indeterminate fragment of Baculites.

Spath’s first list of the Barra do Dande ammonites (Spath 1951: 9, 10) corresponds

CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA 403

exactly with the list given above, but his later list (1953: 49, 50) included in addition
all the Angolan Maastrichtian ammonites described by Haughton (1925) and Haas
(1943) which came from other localities. Beeby Thompson, whose collection
consisted only of six specimens of Nostoceras hyatti and one N. helicinum, gave no
details of the beds at Barra do Dande. Henrique O’Donnell gave the following
details (im litt.) to Spath: the Senonian at the mouth of the River Dande is about
60 m. thick, and consists of thick beds of more-or-less laminated marls, alternating
with thin beds of limestone that are often fossiliferous and typically lenticular with
hard crystalline centres; the limestones sometimes contain thin bituminous layers,
and the whole series is characterized by the gigantic Imoceramus langi. O’ Donnell
did not indicate that any of his ammonites came from any particular part of the
series.

To Beeby Thompson’s and O’Donnell’s collections must be added the two
specimens of Nostoceras described by Sornay (1951) and the large Didymoceras
described by Silva (1961). These three ammonites are definitely recorded as having
come from bed 5 of the Barra do Dande section as described by Freneix (1959:
111-113). This is the best and most detailed description of the section, but further
details were given by Darteville & Casier (1943: 85-86, fig. 46; 1959: 267-268).
Bed 5 is a soft sandy limestone containing a band of black silica and is only 0-30 m.
thick; it has been said to be of Campanian age because of the Nostoceras it contains.
The overlying bed 6, also only 0-30 m. thick, is a gritty limestone containing plant
debris, silicified gastropods, coprolites and fish teeth; the latter have been used to
date it as Maastrichtian. Bed 7 consists of Recent deposits. The beds below bed 5
account for the remainder of the 60 metres of beds at Barra do Dande, and there is
no indication that any of them contained the ammonites collected by O’Donnell.
If all the specimens of Didymoceras and Nostoceras in O’Donnell’s collection are
considered to come from bed 5, then the matrix of the specimens of Baculites,
Solenoceras, Polyptychoceras and Manambolites agrees with them exactly—all are
preserved in a hard white limestone, with varying amounts of iron-staining, and the
septate whorls usually consist of recrystallized calcite. The very large specimen of
Sphenodiscus is somewhat different, for there is no recrystallized calcite and no
iron-staining, and it might have come from a different (? higher) bed.

This Sphenodiscus undoubtedly indicates a Maastrichtian date, and probably
Upper Maastrichtian. In Madagascar Sphenodiscus is known in one area, and occurs
in the Upper Maastrichtian above beds with good Lower Maastrichtian ammonites
(Besairie & Collignon 1960: 74, 79). In Europe the main Sphenodiscus fauna occurs
in the Upper Maastrichtian, but one species, S. wbaghsit Grossouvre, also occurs in
the upper half of the Lower Maastrichtian according to the zonal distribution table
of Jeletzky (1951: 18-19). The occurrences of Sphenodiscus in the Middle East and
India are not accurately dateable against other ammonites within the Maastrichtian.
In North America the best stratigraphical sequence of species of Sphenodiscus is
known in northern Mexico (Bose & Cavins 1927). The five zones in the Maastrichtian
are based on Coahuilites and Sphenodiscus, and if the base of this succession
corresponds to the base of the Maastrichtian, then at least the zone of Sphenodiscus

404 CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA

lenticularis (the second zone from the bottom) would come in the Lower Maastrich-
tian. This is a large lenticular species with a highly complicated suture-line. The
zones in Mexico and in the Gulf Coast of the United States have been discussed by
Young (1960), but the question as to where the lower boundary of the Maastrichtian
should be placed is not yet resolved. The other rich faunas of Sphenodiscus in the
United States described and figured by Hyatt (1903) and by more recent workers
(e.g. Reeside 1962: 136) are all Maastrichtian and some are Upper Maastrichtian,
but the majority cannot be dated more accurately. The Angolan Sphenodiscus,
therefore, probably indicates Upper Maastrichtian, but it could be as low as the
upper half of the Lower Maastrichtian.

The remainder of the Barra do Dande ammonite fauna belongs to either the
Polyplocum Zone at the top of the Upper Campanian or to the lower half of the
Neubergicus Zone at the base of the Lower Maastrichtian, and a decision as to
which zone it belongs to does not seem possible in the present state of knowledge of
ammonites from these zones. The most obvious correlation is with the ammonite
fauna of the Nacatoch Sand of Texas described by Stephenson (1941) which contains
two of the same species of Nostoceras, several Didymoceras and Solenoceras, and
occurs below the horizons with Sphenodiscus in the Kemp Clay. Young (1960: 252,
256) is undecided as to whether the Nacatoch Sand is top Campanian or basal
Maastrichtian, but on the whole favours the latter. The presence of Manambolites
in the Angolan fauna appears to favour a top Campanian age, for no species of this
genus can be proved to be Lower Maastrichtian (see above p. 395). It is tempting
to make a comparison with “Manambolites” ricensis Young (1963: 127) which can
be proved to come from the top of the Campanian in Texas, but Young’s species is
so atypical of the genus as regards its suture-line, that it ought to be ignored for
correlation purposes. The other Barra do Dande ammonites are useless for correla-
tion; species of Neophylloceras are relatively long ranging, and Polyptychoceras
pseudogaultianum, the only species common to both the Egito and Barra do Dande
faunas, is said to range throughout the Santonian and Campanian in Japan. The
evidence tends to favour the placing of all the Barra do Dande ammonites, except
Sphenodiscus, in the Polyplocum Zone, Upper Campanian, rather than the Lower
Maastrichtian, but the exact range of the various species of Didymoceras and
Nostoceras has yet to be worked out.

The position of the Campian-Maastrichtian boundary adopted here is between
the Bostrychoceras polyplocum and Pachydiscus neubergicus Zones. This position,
rather than at the base of the Polyplocum Zone, is more likely to be adopted by a
majority of ammonite and micro-palaeontologists. The succession of ammonites
and zones in the European Campanian and Maastrichtian has been discussed at
length by Jeletzky (1951; 1958) who included the Polyplocum Zone in the Cam-
panian on historical grounds. The lower position of the boundary adopted by Haug
(1910), Spath (1953) and other workers is less satisfactory. Reiss (1962) favours the
higher position of the boundary as used by Jeletzky, and has used it in establishing
the Polyplocum Zone age of the phosphate deposits in Israel. Finally Young (1960;
1963: 19-20, 64) accepts this higher position for the boundary and has applied it to

CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA 405

his descriptions of the succession in the Gulf Coast of the United States.

(e) The Carimba fauna

The six ammonites from Carimba consist of the four specimens of Baculites
subanceps, the single specimen of Didymoceras cf. californicum described above, and
one fragment (C. 52728) of a very large indeterminable nostoceratid. The third
fragment of a helically coiled ammonite listed by Spath (1951: 11) as possibly
“Didymoceras hornbyense (Whiteaves) Haughton”’ is missing from the collection.
These ammonites came from the Teba Formation, presumably from the upper part
which is said to be rich in macrofossils (Mouta 1956: 43), and from which Haughton
(1925: 264) obtained his fine fauna of Nostoceras, Didymoceras, Solenoceras, Baculites,
Menuites and Libycoceras, and Haas (1943) his further examples of Nostoceras,
Solenoceras and Axonoceras.

The presence of Libycoceras is sufficient to establish the Upper Campanian age of
at least part of the Teba Formation, for all accurately dated occurrences of this genus
are in the Polyplocum Zone, Upper Campanian (Reiss 1962: 7-12). Another sub-
species of the Angolan form Baculites subanceps subanceps occurs in the Upper
Campanian of California (Matsumoto 1959a@: 130) and Japan (Matsumoto & Obata
1963: 59) (see p. 370 above), and the two are thought to be contemporaneous. Of
the other Teba Formation ammonites, Menuites is relatively long-ranging (? San-
tonian—Lower Maastrichtian) and the heteromorphs could be either Upper
Campanian or basal Lower Maastrichtian in age.

(f) The Benguela and San Nicolau faunas.

Nothing can be added to the discussions and details of these faunas given by
Spath (1951: 6, 9). The Benguela fauna consists of 16 crushed specimens that are
not accurately determinable and not worth describing. The San Nicolau fauna
consists of two specimens of the nautiloid listed by Spath and one indeterminate
Baculites.

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CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA 411

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412 CRETACEOUS AMMONITES AND NAUTILOIDS FROM ANGOLA

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PLATE 1

Fics. 1-4. Douvilleiceras mammillatum (Schlotheim) ? var. aequinodum (Quenstedt).
“Acanthocevas’’ Formation, Dombe Grande, Angola. Servi¢cos de Geologia e Minas, Luanda,
nos. D.G. 306, 308, 309 and 294 respectively.

Fic. 5. Douvilleicevas orbignyt Hyatt. Same formation and locality. D.G. 305.

All figures natural size.

PLATE 1

Bull. B. M. (N. H.) Geol. 10, 10

PLATE 2

Fics. 1-9. Neokentroceras curvicorvnu Spath. Fig. 1, holotype, shore at landing place near
Hanha, Angola; B.M. C. 20116. Figs. 2-7, Praia do Jombo; C. 52556, C. 52553, C. 52573,
C. 52560, C. 52558, C. 52552 respectively. Fig. 8, paratype, shore at landing place near Hanha;
C. 20123. Fig. 9, Praia do Jombo; C. 52554.

Fics. 10-15. Neokentrocevas singulave Haas. Praia do Jombo, Angola. C. 52583,
C. 52586, C. 52585, C. 52574, C. 52579, C. 52597 respectively.

Fic. 16. Neokentrocervas crassicostatum sp. nov. Paratype, Praia do Jombo, Angola.
C. 52600.

Figs. I, 6, 7, 9, 11, 12-16 natural size.

Figs. 2-5, 8, 10 — X1°5

Bull. B. M. (N.H.) Geol. 10, 10 PAE 2

10a 10b

14b

PLATE 3

Fic. 1. Neokentroceras subtuberculatum Spath. Holotype, near Benguela, Angola.
C. 20042.

Fies. 2-4. Neokentroceras trituberculatum sp. nov. Near Catumbella, Benguela, Angola.
Fig. 2, holotype, C. 20285. Figs. 3, 4, paratypes, C. 14819 and C. 20284.

Fies. 5-11. Neokentrocevas pseudovaricosum Spath. Fig. 5, holotype, shore at landing
place near Hanha, C. 20125. Figs. 6-8, paratypes, same locality, C. 20120, C. 20122, C. 20124.
Figs. 9-11, Praia do Jombo, C. 52590, C. 52591, C. 52592.

Fics. 12-15. Neokentroceras crassicostatum sp. noy. Praia do Jombo. Fig. 12, holotype,
B.M. C. 52593. Figs. 13-15, paratypes, B.M. C. 52599, C. 52596, C. 52508.
Figs. I, 2, 4, 9, 11, 12, 14 — natural size.
Figs. 3, 5-8, 10, 13, I5 — X1I°5.

Bull. B. M. (N. H.) Geol. 10, 10 PLATE 3

PLATE 4

Fics. 1-3. Anagaudrycevas mikobokense Collignon. «1 km. north of Egito, Angola.
C. 52637, C. 52643 and C. 52641 respectively.

Fic. 4. Baculites anceps Lamarck. Side and ventral views. Calcaire a Baculites, Manche,
France, C. 382.

Fic. 5. Gaudrycevas vavagurense Kossmat. 1 km. north of Egito, Angola. C. 52657.
All figures natural size.

PLATE 4

Bull. B. M. (N. H.) Geol. 10, 10

PLATE 5

Fics. 1, 2. Gaudryceras vavagurense Kossmat. 1 km. north of Egito, Angola. C. 52658
and C. 52656.

Fic. 3. Baculites subanceps Haughton. Carimba, Angola. Side, dorsal and ventral views.
C. 52730.

Fics. 4, 5. Baculites anceps Lamarck. Calcaire a Baculites, Manche, France. Fig. 4,
Valognes, Manche, C. 70597. Fig. 5, neotype, side and ventral views, ‘““Normandy’’,
Mantell Collection, B.M. (N.H.). 32573 x7/8.

All figures natural size, except fig. 5, x0-9 approx.

PLATE 5

Bull. B. M. (N. H.) Geol. 10, 10

PLATE 6

Fics. 1-5. Baculites anceps Lamarck. Calcaire a Baculites, Manche, France. Fig. 1,
6409. Figs. 2-5, Valognes, Manche, C. 70595, C. 70596, C. 70600 and C. 70630 respectively.

Fics. 6, 7. Baculites subanceps Haughton. Carimba, Angola. Fig. 6, lectotype, South
African Museum no. 6829. Fig. 7, C. 52729.

All figures natural size.

PLATE

Bull. B. M.(N. H.) Geol. 10, 10

PLATE 7
Fic. 1. Baculites subanceps Haughton. Cross section of large specimen. Carimba, Angola.
Paralectotype, South African Museum, no. 6829.
Fics. 2-6. Didymoceras subtuberculatum sp. nov. 1 km. north of Egito, Angola. Fig. 2,
holotype, C. 52701. Figs. 3-6, paratypes, C. 52703, C. 52708, C. 52705, C. 52696 respectively.
Fig. 5c is a view of the lower surface of the spire showing the paired tubercles.

All figures natural size.

Bull. B. M. (N. H.) Geol. 10, 10 AL AMIN 7

PLATE 8
Fic. 1. Didymoceras cf. californicum Anderson. Carimba, Angola. C. 52727.
Fic. 2. Didymoceras cf. angolaense (Haughton). Barra do Dande, Angola. Fig. 2b, view of
top of spire. C. 52739.

Fias. 3,5. Nostocevas helicinum (Shumard). Barra do Dande, Angola. Figs. 5a, b, c, views
of top, side and base of spire. C. 52753 and C. 52738 respectively.

Fic. 4. Didymoceras cf. hornbyense (Whiteaves). Barra do Dande, Angola. 4a, b, c, views
of top, side and base of spire. C. 52737.

Fic. 6. Nostoceras cf. kevnense (Anderson). Barra do Dande, Angola. Views of side and
base of body chamber hook. C. 52746.

All figures natural size.

PIL ANIIS, £5)

Bull. B. M. (N. H.) Geol. 10, 10

PLATE 9

Fics. 1, 2. Nostoceras hyatti Stephenson. Barra do Dande, Angola. Figs.
_ views of the outer periphery of the body chamber hook. C. 52743 and C. 527

All figures natural size.

Bull. B. M. (N.H.) Geol. 10, 10 PLATE 9

PLATE to
Fic. 1. Nostocevas hyatti Stephenson. Barra do Dande, Angola. C. 52742.
Fic. 2. Nostoceras (?) obtusum sp. nov. Holotype, Barra do Dande, Angola. C. 52744.

Fic. 3. Nostoceras votundum sp. nov. Holotype, Barra do Dande, Angola. Fig. 3d is a view
of the base of the body chamber. C. 52745.

All figures natural size.

Bull. B. M. (N. H.) Geol. 10, 10 PLATE 10

IPILJNIP IS, iar

Fic. 1. Phylloptychoceras sipho (Forbes). Lectotype, Valudayur Beds (Campanian—
Lower Maastrichtian), Pondicherry, India. Fig. 1c is a view of the top of the loop. C. 51153.

Fic.2. Polyptychoceras pseudogaultianum (Yokoyama). Barra do Dande, Angola. C. 52754.

Fic. 3. Desmophyllites diphylloides (Forbes). Lectotype, Valudayur Beds (Campanian—
Lower Maastrichtian), Pondicherry, India. C. 22682, x1I°5.

Fics. 4-6. Kitchinites angolaensis sp. nov. 1 km. north of Egito, Angola. Fig. 4, paratype,
with fragment of Didymoceras subtuberculatum in matrix, C. 52682. Fig. 5, holotype, C. 52675.
Fig. 6, paratype, C. 52680.

All figures natural size, except fig. 3, x1°5.

Bull. B. M. (N. H.) Geol. 10, 10 MILANI, JU

Fics. 1, 4. Eupachydiscus pseudogrossouvyei Collignon. 1 km. north of Egito, Angola.

PLATE 12

C. 52670 and C. 52674 respectively.

Fic. 2.
Fie. 3.

Manambolites dandensis sp.nov. Paratype, Barra do Dande, Angola. C. 52734.
Hoplitoplacenticeras cf. maryoti (Coquand). 1 km. north of Egito, Angola. C. 52685.

All figures natural size.

Bull. B. M. (N. H.) Geol. 10, 10 ALAN, V2

PLATE 13
Fic. 1. Manambolites dandensis sp. nov. Holotype, Barra do Dande, Angola. C. 41474.

Fic. 2. Hoplitoplacenticeras cf. costulosum (Schliiter). 1 km. north of Egito, Angola.
C. 52686.

Fic. 3. Hoplitoplacenticeras cf. marvoti (Coquand). 1 km. north of Egito, Angola. C. 52684.
All figures natural size.

Bull. B. M. (N. H.) Geol. 10, 10 PLATE 13

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THE CORALS

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-D. KALJO anp E. KLAAMANN

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hey} BULLETIN: OF |
BRITISH MUSEUM (NATURAL HISTORY)
BRE Mca | Vol. 10 No. 11
~ LONDON : 1965 |

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ioe FAUNA OF THE PORTRANE
LIMESTONE, tH

7 DEC1965
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LHe CORALS

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DIMITRI KALJO
AND

EINAR KLAAMANN

(Institute of Geology, Academy of Sciences of Estonian S.S.R., Tallinn)

Php. 413 — 434; 4 Plates ; 1 Text-figure

BULLETIN OF
THE BRITISH MUSEUM (NATURAL HISTORY)
GEOLOGY Vol. to No. 11
LONDON : 1965

THE BULLETIN OF THE BRITISH MUSEUM
(NATURAL HISTORY), instituted im 1949, 1s
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 Vol. 10, No. 11 of the Geological
(Palaeontological) series. The abbreviated titles of
periodicals cited follow those of the World List of
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Issued December, 1965 Price Eighteen shillings

THE EAUN AOR’ THEY PORTRANE
LIMESTONE, Ill

TRE (CORALS

By D. KALJO anp E. KLAAMANN

CONTENTS

Page

I INtrROopDUCTION : é : : : : : : 416
Il SySTEMATIC DESCRIPTIONS : c : : : . : 410
RuGosa By D. Karjo . : F é : : 416
Family StTREPTELASMATIDAE Nicholson : : : : : 417
Kenophyllum sp. : : : : : : 417
Kenophylium cf. inflatum (Dy bore ski) . 3 : Z ; 417
Streptelasma fragile Wilson 0 : ; é : : 418
Streptelasma distinctum Wilson . ; 0 : : , 418
Streptelasma cf. vusticum (Billings) : : : ; : 419
Grewinghia europaea (Roemer) . : é ° ; : 420
Grewingkia hibeynica sp.nov. . : : : : : 420
Brachyelasma ct. duncani (Dybowski) . ; . : : 421
Dalmanophyllum subduplicatum (MW ane : : : j 422
TABULATA BY E. KLAAMANN : c 3 : : 22
Family Syringophyllidae Pocta . F : F : c 422
Sarcinula sp. . ‘ : F : : : : 22
Family Lyoporidae ies , : 3 ; ; é ‘ 423
Reuschia sp. . 4 : : ; é : : : 423
Reuschia ? sp. , : . : : 424
Family lee idee aginenes & Evan : 3 : F é 424
Catenipora tapaensis (Sokolov) . ‘ : : ‘ ¢ 425
Catenipora wrighti sp. nov. : : : 2 , : 427
HELIOLITOIDEA By E. KLAAMANN . é . ; : : 428
Family Coccoserididae Kiaer : : : : : 428
Coccoserididae gen. et sp. indet. P : ‘ ; ' 428
Esthonia astevisca (Roemer) . : : ; . : 429
Pragnellia cf. avborescens Leith : é : 5 5 430
Family Heliolitidae Lindstr6ém . : ; : 3 5 430
Wormsipora hirsuta (Lindstrém) i : ; : : 430
Wormstpora portranensis sp.nov. . ; ; ¢ : 431
Family Proheliolitidae Kiaer . 6 . . 2 . 432
Proheliolites dubius (Schmidt) . : : i : : 432

Ill REFERENCES . 5 7 . A 2 j 3 : - 433

SYNOPSIS

The present work forms part of a series of papers dealing with the fauna of the Portrane
Limestone and contains a description of 20 species of corals—Rugosa, Tabulata and Heliolitoidea
—of which three are new. The corals from the Portrane Limestone have much in common with
those of the Norwegian 5a and Estonian Pirgu Stages. For this reason it may be assumed that
the Portrane Limestone is of early Ashgill age.

All the figured specimens are now in the British Museum (Natural History).

4106 THE CORALS OF THE PORTRANE LIMESTONE
I INTRODUCTION

THE present work, representing a part of the study of the Portrane Limestone fauna,
is based on a small collection of corals kindly put at the disposal of the authors by
Dr. A. D. Wright of Queen’s University, Belfast, to whom they wish to express their
sincerest thanks.

The corals were etched out from the rock by chemical methods. As they are
considerably silicified and rather fragile, it was not possible to apply the usual
method of study by means of thin sections, and the examination was restricted to
external observations, and, in the case of the Rugosa, to an examination of the visible
part of the calice only. In a number of cases, in the course of preparation of the corals
by the chemical methods, some skeletal elements were more dissolved than others,
or even disappeared altogether, and, as a result, the natural structure had undergone
alteration. Therefore the entire collection was not determinable to an equal degree
of exactitude, and a large part of it had to be left aside.

However, it has been possible to define an interesting complex of corals, a
description of which follows. For each species, the distribution outside Ireland is
given. Here it is of interest to note that the majority of the fauna studied is known
to occur in Norway and Estonia and some species in the Richmondian of North
America. Among them are such typical Upper Ordovician species as Grewingkia
europaea (Roemer), Catentpora tapaensis (Sokolov), Proheliolites dubius (Schmidt)
and others.

A detailed examination of the fauna of the Portrane Limestone proves it to have
a great resemblance to that of the Norwegian 5a and Estonian Pirgu Stages. In the
complex described, the typical species of the Norwegian 5b and Estonian Porkuni
Stages are practically absent. Thus the Portrane Limestone clearly belongs to the
early Ashgill.

Recently Kaljo, Klaamann & Nestor (1963) showed that the Ashgillian coral
faunas of Estonia and Norway have many features in common. On this basis it may
be briefly stated that, commencing with the Ashgillian, a uniform coral fauna was
developed throughout the North European zoogeographical province and that it was
distributed over a wide area.

II SYSTEMATIC DESCRIPTIONS
RUGOSA
By D. KALJO

The Rugosa of the Portrane Limestone are rather varied and numerous.
Unfortunately the poor state of preservation does not allow all the details of their
structure to be observed, the best preserved and most clearly seen parts being the
calices. Whilst studying this material, the author came to the conclusion that the
recent investigators of corals have paid too little attention to the calice. The details
of its structure are features worthy of specific importance at least. However, the
present state of knowledge of the Rugosa is such that, before the structure of the
calice can be used in taxonomy, it will be necessary to study good material in order

THE CORALS OF THE PORTRANE LIMESTONE 417

to correlate the characteristic features of the calice with those internal features which
are usually given taxonomic importance.

It is of interest to note in the Portrane specimens the presence of a varying scar
of fixation which was observed in nearly all of the species examined. These scars
may be narrow, slit-shaped (Pl. 1, fig. 6), of varying size, sole-shaped (PI. 1, fig. 12),
or burrow-shaped. Their frequent occurrence and rather considerable size (the scar
in Pl. 1, fig. 12, being 32 mm. long and 16 mm. wide in a corallum only 55 mm. long)
shows that these rugose corals lived in relatively mobile water where it was necessary
to have a firm attachment. The varying shape of the scars points to the fact that
fixation occurred either directly on to the rough detrital bottom or on to larger
bodies of an elongate or flat shape.

Family STREPTELASMATIDAE Nicholson
Genus KENOPHYLLUM Dybowski 1873

Kenophyllum sp.
(Bl tigss 12)

DEscriPTION. The corallum is simple, medium-sized, horn-shaped, with the
proximal part trochoid and the distal ceratoid; the incomplete length is 36 mm. and
the diameter 22 mm. The septa are thick and fill the whole lumen in the proximal
part, but distally they become slightly thinner, with narrow interseptal loculi
between them. The exact number of major septa is not certain, but it approaches
36-38. They reach to the axis, but their axial parts are to some extent separated
from the rest of the septa and anastomose with each other, forming a compact axial
structure, the elements of which are mostly of an irregular, oblong shape. The
peripheral stereozone is narrow. The tabulae are not seen.

REMARKS. The state of preservation of the specimen studied does not allow an
exact identification, but it is obviously an undescribed species. The closest form seems
to be Kenophyllum canaliferum Kaljo (Nabala Stage, Upper Ordovician, Estonia),
which, however, differs from the Portrane specimen in external appearance, the
number of septa and, probably, the shape of the calice. With respect to the number
of septa and, to some extent, the external appearance, the form described also
resembles K. subcylindricum (Dybowski) (Upper Ordovician, Nabala, Vormsi and
Pirgu Stages, Estonia), although the latter has well-developed minor septa.

Kenophyllum cf. inflatum (Dybowski)
(PI. 1, figs. 3-5)
DESCRIPTION. The corallum is simple, small, mostly trochoid, the proximal part
slightly curved. A deep, saucer-shaped calice makes up about two-thirds of the

length of the corallum. The largest specimen measured is 24 mm. in length and
20 mm. in diameter, but more commonly the length varies from 16-19 mm. with a

418 THE CORALS OF THE PORTRANE LIMESTONE

diameter of 12-16 mm. The septa in the calice are short, but in the proximal part
the major septa reach the axis. The major septa vary in number with the growth
of the calical diameter, as follows (diameter in mm.: the number of major septa) :—
12: 24; 13: 28; 15:30; 20:33. It may be noted that the increase ofthe septa
distally slows down in comparison with the growth of the diameter—in other words,
in the distal direction the intervals between the septa become larger. The minor
septa are very short. The cardinal septum may be placed on either the convex or
(though less frequently) the concave side of the corallum. The cardinal fossula is
small and narrow. No tabulae were observed.

REMARKS. Dybowski (1873: 347) gave a very brief, unillustrated description of
Petraia inflata of the Estonian Upper Ordovician, which is very closely related to
the Portrane specimens, but which is larger, with a greater number of septa. Kaljo
(1958: 24), pointing out that P. inflata differs from Kenophyllum siluricum (Dybowski)
only in external appearance, treated both forms as one species. At present, however,
the author attributes a greater taxonomic significance to the details of the calice and
considers it necessary to revise this group of Rugosa; therefore for the time being
he considers the Portrane forms as K. cf. inflatum (Dybowski).

In Estonia the corals of the znflatum type occur in the Upper Ordovician Vormsi
Stage and are rather rare in the lower part of the Pirgu Stage.

Genus STREPTELASMA Hall 1847

Streptelasma fragile Wilson
(Biz figs: 6577)

1926 Streptelasma fragile Wilson: 11, pl. 1, figs. 1, 2

DESCRIPTION. The corallum is small, slender, ceratoid, the proximal part
slightly curved. The largest specimen measured is 24 mm. in length and 9 mm. in
diameter. The calice is funnel-like, deep. Septa thin, the cardinal septum placed
on the convex side, generally off the plane of the greatest curvature. In the proximal
part, the major septa reach the axis, their number being 16-20 in the case of a
diameter of 5-6 mm. The minor septa are short, but distinctly visible. Walls thin;
no tabulae have been observed.

REMARKS. This splendid, small Rugose coral was described by Wilson (1926)
from the Richmondian of the Rocky Mountains. The Portrane specimens agree well
with its description, the Canadian specimens differing only in possessing a somewhat
deeper calice.

Streptelasma distinctum Wilson
(Pl. 1, figs. 8, 9)

1926 Streptelasma distinctum Wilson: 12, pl. 1, figs. 6, 7.
1958 Streptelasma bystvowi Reiman: 33, pl. 1, figs. 4—6.

THE CORALS OF THE PORTRANE LIMESTONE 419

DESCRIPTION. A small or medium-sized, horn-shaped, ceratoid or trochoid
simple coral. Calice funnel-shaped with a wide bottom, one side of the calice being
more sloping than is usual. The walls thin, the edge sharp. Major septa long,
reaching the axis, where they may communicate with each other to some extent, or
even intertwine. In the axial region some sparse pali-like structures may be observed.
The number of major septa in the calice amounts to 43 (the diameter of the corallum
at the bottom of the calice being 18-20 mm.). Minor septa are very short, the
peripheral stereozone narrow. Tabulae are strongly convex at the periphery, and in
the middle they are wavy.

REMARKS. This species belongs to the group of Streptelasma corniculum Hall,
one of whose peculiar features is a simple axial complex. In the number of septa, it
bears a similarity to S. orventale Kaljo (1958: 21, pl. 2, figs. 1-4—-from the upper part
of the Estonian Middle Ordovician), which, however, differs from it in the arrange-
ment of the septa and the nature of the tabulae. S. poulseni Cox (1937: 9, pl. 2,
figs. 8a—c, ga—-b—Cape Calhoun formation, Greenland) is even more similar but
differs mainly from it in size and in the flatter and more numerous tabulae.

It is obvious that this group of species requires a thorough revision, based on
reliable material.

S. distinctum has been previously described from the Richmond formation of the
Rocky Mountains, British Columbia, aid from the Pirgu Stage of Estonia.

Streptelasma cf. rusticum (Billings)
(Pl. 1, fig. 10)

DEscRIPTION. Simple, medium-sized, ceratoid coral. The specimen is broken
and its incomplete length is only 23 mm. The cup-shaped calice has thick vertical
walls and a convex floor. The external diameter of the calice is 23-27 mm. and the
internal diameter 15-17 mm. The depth of the calice is 12 mm. The major septa
almost reach the axis but leave the axial area free, revealing an axial structure which
consists of separate elements. The number of major septa at the bottom of the
calice of a corallum with a diameter of 19-21 mm. is 41. Minor septa in the calice
are rather short, but lengthen to some extent in the proximal direction. The calical
edge is rather thin. Tabulae are convex in the peripheral part.

REMARKS. Streptelasma rusticum (Billings) has been described by Billings (1858)!
and Lambe (1901) from the Hudson River formation of Canada, by Cox (1937) from
the Richmondian of Canada and Ohio, by Wang (1948) from the Girvan Stinchar
Limestone Group, and by Kaljo (1961) from the Estonian Pirgu Stage (Upper
Ordovician). In these descriptions there is a considerable difference as to the axial
structure: according to Lambe the major septa are “passing to the centre, where
they are often considerably twisted’’, and further, ““Dissepiments . . . forming with
the twisted inner ends of the primary septa the confused central structure charac-

1The author has not been able to obtain this work. The reference is taken from Lambe (1901 :110).

420 THE CORALS OF THE PORTRANE LIMESTONE

teristic of Streptelasma’’ (Lambe 1901: 111). The later authors, however, deal with
the forms of S. vusticwm whose major septa nearly reach the axis and whose axial
structure is formed of the isolated inner ends of septa. Cox alone notes that the
larger forms may have an anastomosing axial structure. The present author is of
the opinion that in this instance two different species were dealt with, the larger
forms coming from the Arctic being the genuine vusticum and representing the real
Grewingkia, whereas the Ohio, Girvan and Estonian forms are nearer to Stveptelasma
and obviously form a new species. The final solution of this problem, however,
requires better and more complete material than that currently at the author’s
disposal.

The Portrane form, by the number of its septa, shape of the calice and wide
stereozone is very closely related to the Girvan form, differing to some extent from
the Estonian specimens. It also resembles S. craigense (M’Coy), though the charac-
teristic feature of the latter is the occurrence of long minor septa.

Genus GREWINGKIA Dybowski 1873

Grewingkia europaea (Roemer)
(Elaers festa)

1861 Stveptelasma euvopaeum Roemer: 16, pl. 4, figs. 1a-f.

1933 Kiaerophyllum anguineum Scheffen: 23, pl. 3, figs. 3, 4.

1948 Streptelasma (Kiaerophyllum) europaeum (Roemer) Wang: 103, pl. 7, figs. 1a—b, text-fig. 4.

1961 Streptelasma (Grewingkia) euvopaeum euvopaeum (Roemer) Kaljo: 57, pl. 2, figs. 2-9,
text-fig. 3.

DESCRIPTION. Simple, conical, medium-sized corallum. The cup-shaped calice
is of medium depth, with thin, almost vertical walls, and its floor convex. Septa
somewhat thickened in ephebic stages. The major septa number 40 in the case of
a diameter of 16 mm. and reach the axial structure, which is wide and consists of
connected septal ends of different shapes. The peripheral stereozone is narrow,
I-1.5 mm. The minor septa project to some extent from the stereozone. The
tabulae are abruptly convex at the periphery.

REMARKS. The Portrane specimens, though somewhat smaller, are very closely
related to the Estonian and other forms in their general structure. G. europaea
differs from the species of the G. buceros group in possessing a very narrow stereozone
and an axial structure which is not compact.

The species is found in the Pirgu Stage of Estonia, in the Norwegian Stage 5a,
and in the Stinchar Limestone Group of Girvan.

Grewingkia hibernica sp. nov.
(Pl. 1, figs. 12-14)

Diacnosis. Grewingkia of moderate size, straight or moderately curved, the

THE CORALS OF THE PORTRANE LIMESTONE 421

calice shallow. Septa short, but in the calice relatively long. The axial structure
wide, about one-third of the diameter of the corallum.

HoLotTyPe. R.453109.
FIGURED PARATYPES. R.45318, R.45512-13.

DEscrRIPTION. Mostly medium-sized, straight or moderately curved Rugose
corals. The length of the corallum attains 70 mm., the greatest diameter 40 mm.
The epitheca is covered with poorly preserved rugae and sometimes reveals horizontal
growth-rings. The calice is shallow (9 mm. in the holotype), and, as a result of the
axial structure penetrating to some extent into the calice, has a slightly convex
floor. The septa in the calice are long at the base and only gradually shorten towards
the upper rim of the calice. The septa are moderately thick. The major septa reach
the axial structure where they may form compact groups connected by septal ends.
The holotype has a diameter of 25-28 mm. and 50 major septa; in another specimen
with the diameter of 33-38 mm. their number is 54. The minor septa are relatively
long, about one-fifth to one-quarter of the length of the major septa. The stereozone
is narrow (I-2 mm.) and segmented. The axial structure is wide, occupying
approximately one-quarter of the diameter of the corallum, and consists of a complex
of granular and oblong axial elements, intertwined with each other. The tabulae,
which could be examined only in some fragments, showed a curvature at the
periphery.

ReMARKS. The Portrane form differs from all the other Grewingkia species in
the peculiar structure of its calice.

Genus BRACHYELASMA Lang, Smith & Thomas 1940

Brachyelasma cf. duncani (Dybowski)
(Pl. 1, fig. 15)

DESCRIPTION. Corallum simple, ceratoid to cylindrical, somewhat compressed,
medium-sized. The corallum is about 40 mm. in length and the maximum diameter
18-20 mm. The calice is cup-shaped, with thin vertical walls and flat floor. The
stereozone is narrow. Septa thin and short, the axial area open, containing only
some single “‘pali’”. Minor septa short. Tabulae rather curved at the periphery,
flat or slightly wavy in the middle.

RemMArRKS. The form described from the Portrane Limestone is closest to
B. duncami (Dybowski) (5a of Norway, Pirgu Stage of Estonia) in its general size
and shape as well as in the width of the stereozone and number of septa. Owing to
ignorance of some details of the structures (e.g. that of the stereozone and of the
axial zone in ontogeny), it is impossible to give a precise identification of the Portrane
specimens. B. undulatum (Scheffen), from Stage 5a of Norway, is also closely
related, but the latter has a greater number of septa. The other species of
Brachyelasma have either longer septa or a different axial structure and a wider
stereozone.

422 THE CORALS OF THE PORTRANE LIMESTONE

Genus DALMANOPHYLLUM Lang & Smith 1939

Dalmanophyllum subduplicatum (M Coy)
(Pl. 1, figs. 16-18)

1850 Petraia subduplicata M’Coy: 279.
1878 Lindstrémia subduplicata (M’Coy) Nicholson & Etheridge: 86, pl. 6, figs. 2-2f, text-fig. 4.

DESCRIPTION. Corallum simple, small, ceratoid. Maximum dimensions: length
22 mm., diameter 15 mm. Epitheca covered with fine rugae. The funnel-shaped
calice has a sharp rim. A strong axial column, consisting of a large central element
surrounded by intertwined, separated, small septal ends, penetrates into the calice,
below the floor of which it is rather wide, occupying about one-half of the diameter
of the lumen. The number of major septa is 27-31 when the diameter of the calice
is I2-15 mm. The minor septa are rather short. Between the major septa, particu-
larly in the distal part of the coral, the interseptal loculi are wide. The peripheral
stereozone is narrow. The tabulae are convex.

ReEMARKS. The Portrane Limestone specimens are very similar to those from
Girvan described by Nicholson & Etheridge (1878), except that the septa in the
proximal part of the former are less thickened by stereome than those of the latter.
I am not altogether convinced that some of the interseptal loculi in the proximal part
of the corallum have not become wider in the course of the chemical preparation.

D. subduplicatum has been described as occurring in the Craighead Limestone
(Caradoc) and Upper Llandovery of Girvan, the Upper Ordovician of Wales, and in
Stage 5a of Norway (Kiaer 1897).

TABULATA
By E. KLAAMANN

Order SARCINULIDA
Family SYRINGOPHYLLIDAE Poéta 1902
Genus SARCINULA Lamarck 1816

Sarcinula sp.
(Pl. 2, figs. 1-4)

DEscRIPTION. Corallum nodular, irregularly shaped, the maximum diameter
being 40 mm. and the maximum height 35 mm. On account of the poor state of
preservation at the surface of the colonies, only the rounded openings of the inner
cavities can be observed there: their diameters are about 2:5—3-0 mm. and they are
placed at intervals of 2-5-3-0 mm. from each other. In some cases it was possible to
measure the true diameter of the corallites, namely, 3:5 to 3-7 mm. and in rare cases
even 4:°0mm. The walls of the corallites are thick, 0-7-1-0 mm. The numerous pores
penetrating the walls of the corallite in horizontal rows can be clearly seen. These
rows of pores open between the plates connecting neighbouring corallites. The

THE CORALS OF THE PORTRANE LIMESTONE 423

connecting plates are very closely arranged, without plate-free intervals, and their
average number is 6 in 5 mm. Thus the intercorallite tissue shows considerable
resemblance to that of Calapoecia. The tabulae are badly preserved; they are
slightly concave or curved and spaced at intervals of 0-5 to 3:5 (?) mm. The septal
apparatus is represented by short laminar septa, whose number in a corallite exceeds
20 (probably amounts to 24). In a number of places thin ray-like “‘costae’’ are seen
to diverge beyond the limits of the corallite forming a peculiar septal halo around it.

REMARKS. The relatively large distance between the corallites and the nature
of the walls and of the septal apparatus show that, in spite of the intercorallite tissue
resembling that of Calapoecia, we have here a typical representative of Sarcinula.
Unfortunately, the unsatisfactory state of preservation of all the structural detail
does not permit of an exact identification with any known species.

The Irish specimens bear the strongest resemblance to S. luhai Sokolov (1951:
92-94, pl. 16, figs. 6-7; pl. 17, figs. 1-2) of the Pirgu Stage of Estonia and Stage 5a
of Norway. This species possesses corallites of almost the same diameter (most
frequently 3:5-3-7 mm.), closely proximate rows of pores, and connecting plates
without plate-free intervals between them. In the size of its corallites, the Irish
species also resembles S. latwm Sokolov (1951: 91-92, pl. 16, figs. 3-5), but the
corallum of the latter always has a flat discoid shape, and between the connecting
plates there are sharply outlined free intervals of 0-5—3-00 mm. in width. S. latwm is
also known from the Pirgu Stage of Estonia.

Until recently it was assumed that the only representative of Sarcinula was
S. organum (Linné). However, the latest researches in the Baltic area reveal that,
e.g., in the Upper Ordovician of Estonia, this species is represented very rarely and
by only a very limited number of individuals, and that the main réle is played by
other species, and in particular by S. luhai and S. latum. S. organum differs from
those species in the much smaller diameter of its corallites (2°5-3-0 mm.), and thus
is but a rather distant relation to them as well as to the Sarcinula from the Portrane
Limestone. It is possible that the forms from England described and illustrated by
Milne-Edwards & Haime (1854: 295, pl. 71, figs. 3-30) as Syringophyllum organum
are very closely related to the Portrane Sarcinula.

Order LICHENARIIDA
Family LYOPORIDAE Kiaer 1930
Subfamily EOFLETCHERIINAE Sokolov 1955
Genus REUSCHIA Kiaer 1930

Reuschia sp.
(Pl. 2, fig. 5)

DESCRIPTION. The collection contains a small fragment (15 x 15 mm.) of a
colony consisting of 17 thick-walled, tubular corallites, which now and then are in
contact with each other along their whole length, or stand at a distance of I-1-5 mm.
from each other. The diameter of the corallites varies from 1-8 to 2:2 mm. compared

424 THE CORALS OF THE PORTRANE LIMESTONE

to which the thickness of the walls seems striking—o-6—0:8 mm. and in some cases
even 1 mm. Hence the interior vacuity is very narrow (PI. 2, fig. 5) and seldom
exceeds 0:5-0'8 mm. in diameter. At the openings of the corallites the thick walls
show a trabecular structure, but owing to the poor state of preservation, it was
impossible to determine the number of trabeculae. Tabulae were not observed.

REMARKS. Up to the present time the only representatives of Reuschia which
have been described are those of the Upper Ordovician of Norway (Kiaer 1930;
Hill 1953) and China (Yi 1960). All these investigators define only one species,
R. aperta Kiaer. The Portrane specimen differs from typical Norwegian repre-
sentatives by having corallites of smaller diameter which are in closer contact.
The Chinese F. aperta, however, has even larger corallites than the Norwegian form,
and in addition has thicker walls; thus it seems that in this instance a new, separate
species should be instituted.

Reuschia? sp.
(Pl. 2, fig. 6)

DESCRIPTION. The small bushy colony does not exceed 40 mm. in height. It is
composed of cylindrical corallites budding like Auwlopora and forming bunches of
corallites, the central ones of which are orientated in a more or less vertical direction,
whilst those at the outside bend slightly towards the periphery. The diameter of the
corallites is constant throughout their whole length, mostly amounting to 2:5-3-0 mm.
The calices are deep, with a circular cross-section and smooth rims. The better
preserved corallites show a slight contraction at the opening, the calices developing
a barrel-like shape. The thickness of the walls varies between 0-5 and 0-7 mm. They
are composed of narrow trabeculae whose ends, in some corallites, extend inwards
beyond the stereozone and, owing to their dense arrangement, form low vertical
rugae. The latter are the only structures in the interior cavity of the corallites, since
tabulae are missing altogether.

REMARKS. The mode of budding and the form of the corallites stress the great
similarity of this species to Eofletcheria. However, the total absence of tabulae and
the comparatively great thickness of the corallite walls indicate that we may consider
the specimen to belong to Rewschia. Of the representatives of this genus, R. aperta,
described by Yui (1960:97-08, pl. 9, figs. 4-5; pl. Io, figs. 5-8) from the Upper
Ordovician of China, bears the greatest resemblance to the Portrane specimen, from
a consideration of the size of the corallites, at least.

Order HALYSITIDA
Family HALYSITIDAE Edwards & Haime 1850
Subfamily CATENIPORINAE Hamada 1957
Genus CATENIPORA Lamarck 1816

The Halysitida are represented in the collection by more than 60 small irregular

THE CORALS OF THE PORTRANE LIMESTONE 425

colonies or parts of colonies. The specimens are, however, poorly preserved, so that
in many instances it was impossible to examine the tabulae and the septal spinules
and to establish the original thickness of the walls of the corallites. Accordingly,
of the principal criteria that normally serve as a basis for taxonomic determination
of the order, only the dimensions of the corallites and the form of the lacunae could
be used. These two characters do, however, indicate two groups of forms, one of
which is certainly identical with Catenipora tapaensis (Sokolov), a species of wide
distribution in the Upper Ordovician of Baltoscandia.

Catenipora tapaensis (Sokolov)
(Ple2, fie: 12)

1854. Halysites catenularia (part.); Edwards & Haime: 270-272.

1858. Catentpora labyrinthica Fischer (part.) ; Schmidt: 229.

1860. Halysites eschavoides Lam. (part.); Eichwald: 507.

1915. Halysites eschavoides Fischer-Benzon; Yabe: 34 (10), pl. 6 (2), figs. 3, 4.
1951. Palaeohalysites tapaensis Sokolov: 81-82, pl. 14, figs. I, 2.

1951. Palaeohalysites prirsaluensis Sokolov: 84-85, pl. 14, figs. 5-7.

1951. Palaeohalysites kuruensis Sokolov: 85-86, pl. 15, figs. 3, 4.

1955- Palaeohalysites privsaluensis Sokolov; Sokolov, pl. 65, fig. 2.

DESCRIPTION. The corals have bushy, hemispheric or weakly cushion-shaped
colonies whose diameter does not exceed 10 cm. The corallites form irregular nets
on the sides of whose meshes are 1 to 6 corallites, in most cases 2 to 4. The lacunae
are irregularly polygonal, mostly curved and oblong; their maximum diameter
varies between 3 and 15 mm. Transversely the corallites are elliptical, the longer
axis I-3 to 1-7 mm., the shorter 0-9 to 1:2 mm. (Text-fig. 1, I)—there are almost no
variations of these dimensions. The corallite walls are rather thick, 0-2-0-3 mm.,
and those between adjoining corallites are about twice as thick. The interval
between the horizontal or slightly concave tabulae amounts to 0:5 to o-°8 mm. On
account of the silicification, the septal spinules have been poorly preserved, occurring
rarely; the corallites probably possessed twelve rows of spinules originally.

Remarks. The Portrane forms reveal almost absolute similarity to Baltoscandian
representatives of C. tapaensis, differing from them only in the somewhat lesser
convex form of the corallite walls. This is expressed by the fact that the average
long transverse diameter of the corallites of the former is approximately 0-I mm.
greater and the shorter diameter about 0-1 mm. less than the corresponding average
measurements of the Estonian and Norwegian representatives of this species.

As seen in the synonymy, the conception of the species C. tapaensis in the present
work is much wider than that of the author of the species who distinguished three
separate species. This subdivision was based on small differences in the form of the
corallites, in the thickness of their walls and in the development of septal spinules.
The investigation of a great number of specimens of Catenipora from the Upper
Ordovician of Estonia has shown that C. tapaensis (sensu Sokolov), C. piirsaluensis
and C. kuruensis, established by Sokolov (1951) on the basis of limited material, are

426 THE CORALS OF THE PORTRANE LIMESTONE

min Dp /4

2,0

1,0

Long diameter of coraliite

Q5 1,0 15 mm
Short diameter of corallite

Fic. 1. Average dimensions of Cateniporva tapaensis (Sokolov) (1)
and C. wrighti sp. n. (II) computed from 22 and 9g colonies, respectively.

really connected with each other by a large number of transitional forms. Inasmuch
as all the quoted forms have not only a morphological similarity but also equal
stratigraphical distribution in Estonia, it can be concluded that they belong to one
and the same species, which should be called C. tapaensis (Sokolov) according to
page priority.

In all likelihood, a part of the Halysitids from Portrane described by Edwards &
Haime (1854: 272) under the name Halysites catenularia belong to the species
discussed.

DIsTRIBUTION. Ireland, Portrane Limestone; Norway, Ringerike (Stavnae-
stangen), Upper Ordovician, Stage 5a; Estonia, Upper Ordovician, Vormsi and
Pirgu Stages.

THE CORALS OF THE PORTRANE LIMESTONE 427

Catenipora wrighti sp. nov.
(Pl. 2, figs. 7-11)

Diacnosis. Corallum bushy, diameter not exceeding 50mm. Corallites connected
into small irregular meshes, the sides of which are composed of 4 corallites or less:
corallite diameter 0-7-1-0 X I-I-I-5 mm. Tabulae and septal spinules present.

HOLoTyPE. R.45329, a small corallum, 20 mm. in diameter.
FIGURED PARATYPES. R.45330-33.

LocaLiry AND Horizon. Ireland, Portrane; Upper Ordovician, Portrane
Limestone.

DESCRIPTION. Corallum small, bushy, of irregular form, with a diameter ranging
from 20 to 40 mm. The small elliptical corallites are joined into meshes, at the sides
of which there are usually from I to 4 corallites, though the maximum is 8. As a
result, the shape of the lacunae varies from the more common irregular polygon,
with a diameter of 3-20 mm., to an elongated and meandering form. In single cases
there is a locally dense disposition of the chains, so that the lacunal area is reduced
toa minimum. The average diameter of the corallites is 0-9 x I-3 mm., but it varies
from 0-7-I'0 X I:I-I°-5 mm. The relation of the short diameter of the corallite to
the long one is approximate 1: 1:5 (Text-fig. 1, II). The thickness of the exterior
walls varies from 0-15 to 0:2 mm., the interior walls (those between the corallites)
being somewhat thicker. Tabulae horizontal, their distance apart about 0:5-0-7 mm.
Owing to the changes in the material as well as to the chemical processing, only the
basal part of the septal spinules is preserved, which in places are represented by
short blunt tubercles on the interior walls of the corallites.

RemARKS. Among the undisputed Ordovician Halysitid species known at present
(whose number is less than 20), the dominant representatives belong to Catentpora
and Quepora. These genera have an equal vertical range, and the only criterion for
distinguishing them is the presence or absence of septal spinules in the visceral
chamber of the corallites, a character depending to a great extent on the state of
preservation. As observed by the author, the septal spinules of the Halysitids may
be destroyed by minor diagenetic processes without any striking changes in the
other elements of the skeleton. This circumstance renders a practical application of
these characters extremely complicated. In my opinion, in the current systematics
of the subfamilies Cateniporinae and Halysitinae, too great a significance has been
attached to septal spinules, or, rather, to their absence.

For these reasons a comparison of the new species with the Ordovician species of
Quepora as well as Catentpora is given.

Catenipora wrighti shows the greatest similarity (particularly in the size of
corallites) to C. tapaensis (Sokolov) described above, as well as to Quepora aequabilis
(Teichert) from the Trenton of Arctic Canada, Q. quebecensis (Lambe) from the
Middle Ordovician of Quebec, and Q. (?) parallela (Schmidt) from the Ashgillian of
Estonia (Pirgu and Porkuni Stages). C. tapaensis has larger colonies and thicker
walls, in particular those between corallites, and a greater diameter of corallites

428 THE CORALS OF THE PORTRANE LIMESTONE

(cf. I and II, Text-fig. 1). The majority of the corallites of the new species have a
diameter of 0-9 x 1-3 mm., whereas in C. tapaensis the dimensions 1-0-1:2
1‘6 mm. are of most common occurrence.

Q. aequabilis is distinguished by very small lacunae and much narrower corallites
—only 0-4-0-7 mm.

Q. quebecensis has larger and thicker-walled corallites from which no septal
spinules are known.

The Baltic-species, Catenipora parallela Schmidt (1858: 229), attributed to
Quepora by Hamada (1957), differs only slightly in the dimensions of the corallites
(0-75-0°9 X I:2-I'4 mm.) and thickness of the walls (0-15-0-2 mm.). However, it is
clearly distinguishable by the almost straight parallel walls of the corallites and the
long, curved, commonly unconnected chains. It would appear from this last
mentioned character that Q. parallela ought to be referred to Eocatentpora.

Such Ordovician species as Q. (?) agglomeratiformis (Whitfield), Q. delicatula
(Wilson) (both from the Richmond of Canada), Catentpora obliqua (Fischer-Benzon)
(Nabala Stage of Estonia) and C. tractabilis (Sokolov) (Vormsi Stage of Estonia) are
very different, having considerably larger dimensions of the corallites than
C. wright.

HELIOLITOIDEA
By E. KLAAMANN

Order PROTARAEIDA
Family COCCOSERIDIDAE Kiaer 1899

Gen. et sp. indet.
(Pl. 3, figs. 1-6)

DESCRIPTION. Colonies irregular, flat, with a thickness of 7-15 mm. and a
diameter seemingly exceeding 50-60 mm. A number of specimens have fully or
partly retained a somewhat wavy basal epitheca on the lower surface of the colony.
The upper surface is poorly preserved, showing in single cases indefinite, low
tubercles. The interior of the colony has been etched out; only some parts which
border the lower and upper surfaces of the corallum are preserved. In the cross-
sections of these parts a great number of quadrangular and hexagonal “‘tubules’’
are observed, the diameter of which keeps within the limits of 0-4-0-7 mm. The
vertical sections, however, clearly reveal the pinnate microstructure of these
“tubules”, a proof of their being, in reality, coenenchymal trabeculae which, as a
result of secondary changes, have acquired a form of prismatic tubules of the type
observed in Heliolites. No horizontal structures were discovered.

RemARKs. The laminar corallum, the presence of rough, vertical trabeculae and
the absence of tabulae all indicate that the poorly preserved forms described above
belong to the Coccoserididae. But as the structure of the corallites is unknown to

THE CORALS OF THE PORTRANE LIMESTONE 429

us, a more detailed definition of the material cannot be made. It is most probable
that here we are confronted with representatives of Pvotavaea, a genus widely
distributed in the Upper Ordovician of Baltoscandia, Great Britain and North
America.

Subfamily ACIDOLITINAE Sokolov 1950
Genus ESTHONIA Sokolov 1955

Esthonia asterisca (Roemer )
(Plea; figs. oN 10)

1858. Heliolites inordinata (part.); Schmidt: 228.

1861. Heliolites interstincta Linné; Roemer: 24, 25, pl. 4, figs. 4a, b.

1880. Heliolites intricatus Lindstrom var. lamellosus (part.) Lindstrém: 32, 33, pl. I, fig. 5.

1883. Heliolites asteriscus (part.) Roemer: 505.

1897. Heliolites asteriscus (part.) Roemer; Roemer: 505.

1899. Heliolites intricatus var. lamellosa Lindstré6m; Kiaer: 42-44, pl. 5, fig. 13; pl. 7, figs. 3-5;
text-fig. Io.

1899. Acantholithus asteriscus (Roemer) (part.) Lindstré6m: 113, 114, pl. 11, figs. 31-35.

1903. Acantholithus asteviscus (Roemer); Kiaer: 10-12.

1955. Esthonia asterviscus (Roemer) Sokolov, pl. 71, figs. 1-6.

1955. Esthonia lamellosa (Kiaer) Sokolov, pl. 71, fig. 7.

1962a. Esthonia asteriscus (Roemer); Sokolov, pl. 2, figs. 1a—d.

DEscrIPTION. The material consists of fragments of irregular, wavy and laminar
coralla with a thickness of only 1-5—4-5 mm. On the upper surface of the laminae
are Clearly discernible small, shallow calices placed at a distance of 0:5-1-5 mm. from
each other. The diameter of the calices is 0-9-1'2 mm. They are clearly distinguished
from the internal skeleton consisting of angular, thick-walled, intermediate tubules,
about 0-15—-0-2 mm. in cross-section. The twelve septa penetrate the interior
chamber of the corallites to a depth of 0-2—-0:25 mm. In the central part of the calice
are what appear to be fine tubercles, but which are in reality formed by ends of
axial trabeculae. No tabulae were detected either in the corallites or in the inter-
mediate tubules.

Remarks. The Portrane specimens discussed doubtless belong to typical
representatives of Esthonia asterisca (Roemer), a form frequently described from
the Upper Ordovician of Baltoscandia and most commonly referred to as Heliolites
intricatus var. lamellosa Lindstr6m and Acantholithus asteriscus (Roemer) (see
synonymy). As indicated by Lindstrém himself (1899), the first-mentioned name is
not correct, since at the time of the establishment of the variety the author
erroneously connected under this name two different species of Roemer—Heliolites
parvistellus and H. asteriscus. For these reasons it cannot be considered correct to
restore the name lamellosa, as was done by Sokolov (1955, pl. 71, fig. 7), for
designating the forms of Esthonia asterisca which have a very thin encrusting colony.

In the course of time the species Esthonia asterisca (Roemer) was defined with
greater precision. In order to avoid possible misunderstandings concerning this

430 THE CORALS OF THE PORTRANE LIMESTONE

species it would be advisable first of all to establish its type; if Roemer’s original
collection is lost, we recommend that the specimen from the Vormsi Stage of Estonia
depicted by Sokolov (1955, pl. 71, figs. 1, 2) be used as neotype. Further, it is
imperative to determine with greater precision the date of the establishing of the
species discussed. The year usually quoted—1861—is incorrect, since the name
H. asteriscus was first proposed by Roemer (1883) in his comment on the species
Heliolites inordinata.

DistrisuTion. Ireland, Portrane Limestone; Norway, 5a in Asker and Ringerik e ;
Estonia, Vormsi and Pirgu (?) Stages.

Genus PRAGNELLIA Leith 1952

Pragnellia cf. arborescens Leith
(PL. 3, figs. 7, 8)

DeEscRIPTION. The coralla have a curved, branching form, but at the base of the
colony they swell out and encrust. The diameter of the branches varies from 3 to
8 mm., the length is about 30 mm. Corallites small, rounded, with a diameter mostly
about I-o mm., the maximum being 1:2 mm. Calices very low, with short septa
which have a considerably thickened base. The central part of the calice often
slightly bulges and, when in a good state of preservation, reveals a fine punctuation
caused by the ends of septal trabeculae. The coenenchyme on the surface of the
colony is represented by small tubercles (o-I mm. in diameter). The cross-sections
of colonies also reveal a trabecular structure, the trabeculae being in radial arrange-
ment. The rest of the details of the structure of the corallum have been destroyed.

REMARKS. Pvagnellia is a rare representative of the Heliolitoidea of which only
two species are known at present. The Portrane form resembles most of all
P. arborescens Leith (1952: 795, pl. 11b, figs. 1-8) from the Upper Ordovician of
North America, differing from it by greater intervals between calices on the surface
of the colony and by a lesser forking of branches.

Sokolov (1962, 1962a) gave the following data on the distribution of Pragnellia:
Upper Middle Ordovician—Upper Ordovician of the Urals, Altai, North America;
Pirgu Stage of Estonia.

Family HELIOLITIDAE Lindstrém 1873
Genus WORMSIPORA Sokolov 1955
Wormsipora hirsuta (Lindstr6m)
(Pl. 4, figs. 1-3)

1899. Nicholsonia megastoma M’Coy; Kiaer: 37-39, pl. 6, figs. 8, 9; pl. 7, figs. I, 2.
1899. Heliolites hivsutus Lindstrom: 64, pl. 11, figs. 18-22.

1903. Propora hivsuta (Lindstr6ém) Kiaer: 9, 12, 39-42.

1955. Wormsipora hirsuta (Lindstrém) Sokolov, pl. 74, figs. 1-3; pl. 81, figs. 3, 4.
1962. Wovmsipora hirsuta (Limdstr6m) ; Sokolov, pl. 4, fig. 2.

THE CORALS OF THE PORTRANE LIMESTONE 431

DESCRIPTION. Corallum irregular, slightly elongated in the vertical direction,
varying from 15-30 mm. in width, 20-40 mm. in height; composed of uniform,
star-shaped corallites which often touch each other and whose diameter is I-7—2:0 mm.
The corallites have clear contours, since their walls are considerably thicker than those
of the coenenchymal tubules, which, in addition, have broken contours in cross-
section. The septal apparatus serves as the most important character of the present
species. It consists of numerous coarse spinules bent upwards and penetrating the
corallites to a depth of 0-6 mm. The ends of the spinules are sometimes cleft. The
spinules are arranged in distinct, vertical rows and placed close to each other,
creating the impression not of spinules, but of 12 septal ribs indentated at the rim.
Fine septal growths are to be noticed in places on other septal elements as well.
The cavities of the corallites and coenenchymal tubules are dissected by convex
tabulae and diaphragms. The average distance between tabulae in corallites is
0-4-0°7 mm.

REMARKS. Judging by the good figures of the lectotype and exhaustive
descriptions presented by Lindstrém (1899) and Sokolov (1955, 1962), the Portrane
specimens discussed are identical in minutest details with Wormsipora hirsuta
(Lindstrom) of Estonia.

DISTRIBUTION. Portrane Limestone, Ireland; Vormsi Stage, Estonia.

Wormsipora portranensis sp. nov.
(Pl. 4, figs. 4-9)
Diacnosis. Corallum small, hemispheric or irregular in shape. Diameter of
corallites 2:5-3-°0 mm. Coenenchyme of thick-walled tubules with interrupted

contours in tangential section. Septal spinules, joined at their bases, form 12 coarse
ribs. Tabulae of corallites and tubulae horizontal or gently curved.

HorotyPe. No. R.45344, an irregular colony, 25 X 35 mm.
FIGURED PARATYPES. R.45345-47.

Locatitry AND Horizon. Ireland, Portrane; Upper Ordovician, Portrane
Limestone.

DeEscriPTION. Hemispheric or oblong coralla with a diameter of 15-30 mm., on
the surfaces of which open deep star-shaped calices of corallites, which may be at a
distance of about 2 mm. from each other or may touch each other with their rims.
The rims of the calices are somewhat raised in respect to the coarse-grained surface
of the coenenchymal tissue filling the narrow intervals between the corallites. The
diameter of the corallites keeps within the limits of 2-5-3-0 mm. Longitudinal
sections reveal that the coenenchymal tubules are rather thick-walled with regularly
distributed horizontal diaphragms. The latter are placed more densely than the
tabulae in the corallites. The septal apparatus is represented by 12 coarse ribs,
formed as a result of the union of the thick bases of spinules. Spinules long (0-5-
0-7 mm.), diverging upwards at a sharp angle from the ribs and frequently penetrating
the overlying tabulae. Interval between the tabulae varying from 0-3 to 1:2 mm.

432 THE CORALS OF THE PORTRANE LIMESTONE

REMARKS. In its structure, the new species is strikingly similar to Wormsipora
hirsuta (Lindstrém), from which it differs in the greater diameter of the corallites
and in the joined bases of the spinules, leading to the formation of coarse, spinose
septal ribs.

In its external appearance, the colony is extremely like the form described by
Lindstrém (1880, pl. I, fig. 6) as Plasmopora conferta Edwards & Haime. In all
likelihood this form is also Wormsipora, having, however, even larger corallites of
4 mm. diameter.

Order PROPORIDA
Family PROHELIOLITIDAE Kiaer 1899
Genus PROHELIOLITES Kiaer 1897

Proheliolites dubius (Schmidt)
(Pl. 4, figs. 10-12)

1858. Heliolites dubia Schmidt: 226.

1861. Heliolites dubia Schmidt; Roemer: 26-27, pl. 4, figs. 5a—5b.

1880. Heliolites dubius Schmidt (part.); Lindstr6m: 32, pl. 1, figs. 3, 4 (only).
1883. Heliolites dubius Schmidt; Roemer: 505-500.

1897. Heliolites dubius Schmidt; Roemer: 505-5006.

1897. Proheliolites dubius (Schmidt) WKiaer: ro.

1899. Proheliolites dubius (Schmidt) (part.); Kiaer: 21-26, pl. 3, figs. 5, 6; pl. 6, fig. 5.
1899. Proheliolites dubius (Schmidt) (part.); Lindstr6m: 70-71, pl. 11, figs. 13-17.
1903. Proheliolites dubius (Schmidt); Kiaer: 6, 12.

1955. Proheliolites dubius (Schmidt); Sokolov: pl. 75, figs. 6, 7.

1956. Proheliolites dubius (Schmidt); Hill & Stumm: F461, text-fig. 348, 6a—6b.
1962a. Proheliolites dubius (Schmidt) ; Sokolov, pl. 6, figs. 4a—b.

DEscrIPTION. Corallum irregular, hemispheric or elongated, the maximum
diameter not exceeding 40 mm. Corallites with compact walls, rounded, but owing
to their very dense arrangement, often assuming a polygonal form. They are
surrounded by fine and sparse, mostly triangular or quadrangular coenenchymal
tubulae, whose maximum number around one corallite is four. Corallites with a
diameter of 0-9 mm. predominate, others varying within the limits of 0-8-1-0 mm.
The diameter of the tubulae is about 0-3-0:5 mm. The septal apparatus is very
peculiar, being arranged in 12 rows of short, unconnected spinules which, unlike
those of the other Heliolitoidea, bend downwards. In cross-sections the spinules
are seen as 12 points connected to the inner wall of the corallites. Tabulae horizontal,
in the tubulae rather dense (0:2-0-3 mm. apart) and in the corallites sparser
(o-5-I mm. apart).

REMARKS. The only difference between the forms described and those from the
Baltic consists in the smaller colonies. However, this character is typical of all the

THE CORALS OF THE PORTRANE LIMESTONE 433

Tabulata and Heliolitoidea of Portrane discussed and may have been caused by
ecological factors.

DISTRIBUTION. Portrane Limestone, Ireland; 5a and 5b, Ringerike (Stavnaestan-
gen) and Asker, Norway; Boda Limestone of Dalarne, Sweden; Pirgu-Stage, Estonia.

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434 THE CORALS OF THE PORTRANE LIMESTONE

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pls. I-15.

FIGS. I,

Fic. 6.
INWe5 7.

IG. 3:
Fic. 9.

FIG. ro.

FTG re

Ihe, 12.

PLATE 1
Kenophyllum sp. : : é : ; Pp. 47
2. Two views of the corallum showing the axial structure. IR.45309. x 1.25.

Kenophyllum cf. inflatum (Dybowski) . 3 . 0 [Da Ain?

Corallum. R.45310. xX 2.

,5. Calice and corallum. KR.4531I. x 2.

Streptelasma fragile \Vilson 9 3 . 5 Ds Alanis)

Corallum showing a slit-shaped scar of fixation. KR.45312. x 2.
Two small corals fixed on the bottom with curved sides of the apex. R.45313. xX 2.

Streptelasma distinctum Wilson . : c > 196 Aas)

Bottom of calice. R.45314. xX 1.3.
Longitudinal section. R.45315. x 2.

Streptelasma ci. rusticum (Billings) . ‘ P - p. 419

CalliGeseks7 52 lOmin or

Grewingkia europaea (Roemer) . é F . pp. 420

Calicemss4 56 me =

Grewingkia hibernica sp. noy. : : : . p. 420
Corallum with very wide proximal part and large scar of fixation. R.45318. x 1.2

Fics. 13, 14. Calice and cross-section of holotype. R.45319. x 1.2.
Brachyelasma ci. duncani (Dybowski) 5 0 D420

Fic. 16.
FIG. 17.
Fic. 18.

Corallum, R.45320. x 1.2

Dalmanophyllum subduplicatum (MCoy) . 6 Paa22

Corallum with wide scar of fixation near the apex. .4532I. x
Specimen showing the axial structure. K.45322. x 2.
Calice with axial structure. KR.45323. x 2.

Bull. B. M. (N.H.) Geol. 10, 11 PRATER!

PAV ee

Sarcinula sp. . ; ; F : ae A22

Tics. 1, 2. Transverse and longitudinal sections of an etched corallum. R.45324. x 2.

Fic. 3. Interior of an etched corallum. R.45325. x 2.

Fic. 4. Fragment of a corallum showing horizontal rows of pores and laminated structure of
intercorallite tissue. R.45326. x 2.

Reuschia sp. . : . . - 0 Po 4125)
Fic. 5. A small corallum formed by thick-walled cylindrical corallites. R.45327. x 2.

Reuschia ? sp. . : : : : eps 424

Fic. 6. An irregular bushy corallum. R.45328. x 2.

Catenipora wrighti sp. nov. . : ‘ 4277

ENG 7) ELOlOby pes N« 45920 nm a:
Fics. 8-11. Surface views of small colonies. R.45330-33. x 2.

Catenipora tapaensis (Sokolov) . 5 : DEA 25

Fic. 12. Surface view of an etched corallum showing the varying form and diameter of
lacunae. R.45334. x 2.

PLATE 2

Bull. B. M. (N.H.) Geol. 10, 11

PLATE 3

Coccoserididae gen. et sp. indet. - : : - p. 428

Fic. 1. Basal epitheca of a laminar corallum. R.45335. x 2.
Fic.2. Thesamespecimen. Part of the upper surface showing Protavaea-like structure. x 8.

Fic. 3. An etched laminar corallum. R.45336. x 2.
Fic. 4. Part of the same specimen showing vertical sections of coenenchymal trabeculae.

Figs. 5,6. Typical surface views of a laminar colony. R.45337. x 2 and x 8.

Pragnellia cf. arborescens Leith . : - SP 430

Fies. 7, 8. Irregular cylindrical colonies. R.45338 and R.45339. x 2.

Esthonia asterisca (Roemer) . ° . - p. 429

Fic. 9. Surface view of a thin lamellar corallum. R.45340. x 2.
Fic. 10. Fragment of a lamellar corallum. R.45341. x 8.

Bull. B. M. (N.H.) Geol. 10, 11 PAL ANI 3)

PLATE 4

Wormsipora hirsuta (Lindstrém) . . - ED ASO

Fics. 1, 2. Upper surface and interior view respectively of a small hemispherical corallum.
R.45342. X 2.

Fic. 3. Longitudinal section of corallites showing rugae-like rows of septal spinules. R.45343
x 2.

Wormsipora portranensis sp. nov. . : . - p. 431

Fics. 4,5. Vertical section and upper surface of holotype. R.45344. x 2.

Fics. 6, 7. Surface views of two cylindrical coralla showing the interrupted structure of the
coenenchymal tissue and 12 rows of septal spinules. R.45345, R.45346. x 2.

Fics. 8, 9. Two longitudinal sections of corallites showing massive septal spines directed
upwards. R.45347. x 7 and x 4, respectively.

Fics. to, 11. Upper surface and interior view respectively of an etched corallum. Vertical
section shows horizontal tabulae in the corallites and coenenchymal tubes. R.45348. x 2.

Fic. 12. Thesame specimen. Between the corallites rare polygonal coenenchymal tubes can
be observed. x 8.

Bull. B. M. (N.H.) Geol. 10, 11 PLATE 4

LON
(: e
{7 oec1965 }
z s)
Lig, WSS

INDEX*TO: VOLUME X

New taxonomic names and the page numbers of the principal references are printed in Bold type.
An asterisk (*) indicates a figure.

Acanthoceras 342
Acanthocythere 10
faveolata to
Acantholithus asteviscus 429
Acidolitinae 429
Acinonyx 302
Actinozoa 96
Afrocyon 291
Ailurictis 303
Alatacythere 51
phylloptera 51, 52, 76; Pl. 2, figs. 17, 19
vobusta 51, 52, 75, 76 ; Pl. 2, figs. 7-16, 18
Allicospermum 129
patagonicum 121, 129, 130*, 131; Pl. 1,
figs. 7-9 ; Pl. 5, fig. 28
vetimirum 130, 131
xistum 131
Alopecodon 291
Ammonceratites convadi 371%
Ammonites coesfieldensis 391, 392
cooperi 380
costulosus 391, 393,
diphyllides 388
mamillaries 345
marroti 391
mitis 360
SACYA 357
styiatocostatus 321, 392
vart, 391
var. mayroti 391
Amphicynodon 291
Amphicyon 242, 289, 291, 223-295, 310, 311
americanus 293
dehmi 293, 295
lemanensis 293
MAJOY 293, 295
sinapius 293
(Ictiocyon) dehmi 295
Amphicynoninae 241 288 289, 291
Amphicyonodontinae 291
Amphicytherura 49
cholodon 49, 75, 76; Pl. 1, figs. 6, 7
icenica 49
Amplexopora 111
Amplexoporidae 111
Anagaudryceras 337, 338, 357-360
aureum 358
buddha 358
coalingense 358
crenatum 358
tnvolutum 358
limatum 358
madraspatanum 358

mikobokense 337, 343, 358, 359*, 360, 401, 402 ;
Pl. 4, figs. 1-3
multiplexus 358
povitissimum 358
vevelatum 358
subsacya 358
subtililineatum 358
utaturense 358
yamashitai 358
Anaklinoceras 374
Anasinopa 242, 253, 259, 262, 264, 310, 311
leakeyi 241, 259, 260, 261*, 262, 263, 309 ;
IPA, i, tiles, O; WB IB 2
Ancylopoda 167
Ancylotherium 166, 169, 218, 219, 223, 226, 227*,
PNR, PIO} Ey PEN
gaudryi 216
hennigi 165, 166, 226, 227*, 228*, 229*, 230,
Pe, DEVI DEA Py.)
pentelicum 165, 166, 167, 218,223-226, 227*,
DANS PIX} 5 PIBNO), GB, PVA, PEI A GLY
Angola 337-412
Anisodon larteti 168
magnum 168, 193
schinzit 171%
Antsodon (Choelichotherium) 168
Anoplotherium 168
grande 168
magnum 168
Apterodon 263, 267, 278
Avaucaria mirabilis 121
Archaelurus 302, 303
Archaeopteris 86, 88, 89
jacksoni 83, 86, 87, 88, 90, 91 ; Pl. 1, figs. 1-6,
@) @ Jel, 13
latifolia 88-90 ; Pl. 2, figs. 3-8
macilenta 88, 89, 90
ARCHANGELSKY, S. 119-137
Arctamphicyon 293
arctocyonid 310
Arctocyonidae 241, 242, 243, 311
Arctocyonides 244
Arctocyoninae 243
Arctocyonoidae 243
Arctocyonoidea 241, 243
Ardynictis 246
ARNOLD, C. A. 141, 142
A sciocythere 15
acuminata 15, 16 ; Pl. 2, figs. 10-12 ; Pl. 3,
figs. I-10
lacunosa 16, 23, 24
Ashgillian 416
Atactotoechus 112

436 INDEX

Aulacocythere 10
punctata 10
reticulata 10

Aulopora 424

Austrosphenodiscus 395

Axonoceras 343, 405

Baculites 337, 339, 343, 362-305, 367*, 360%,
379, 402, 405
anceps 337, 339, 363, 364-366, 367*, 368, 369%,
3700 el atic. ae) lies ties 4S ieleOy
figs. 1-5
var. pacificus 368
sublaevis 366
valognensis 363
aspey 370
dissimilis 368
fairbanski 370
fawasii 363
fuchsi 370
leopoliensis 370
palestinensis 370
Sp. 402
subanceps 337, 339, 367*, 368, 369*, 370, 405 ;
TAL, By, titey, 3) 5 IRIE Oy ike, ©, 77 3 elle 7, ithe
subanceps pacificus 370, 405
subanceps subanceps 370
valognensis 363
vertebralis 362, 363, 366, 368
Baculitidae 337, 362
Baiera 125
australis 125
Bairdia 8, 46
angusta 46, 75
fullonica 8
harvisiana 75
hilda 8
stliqua 43, 75
Bairdiacea 8, 42
Bairdiiadae 8
Baluchistan 173
Barinophyton 83, 84, 85*, 86
citrulliforme 83, 86
dawsoni 86
obrutschevii 85
obscurum 86
vichavdsoni 83, 84, 85, 86, 91 ; Pl. 1, figs. 7, 8,
rie 3 IPA, Ap Sikes,
Bate, R. H. 1-33
Batostomella 102
Batostomellidae 102
Bdeogale 301
Benguela basin 341-342
Bennettitales 121
Benthall Edge 96
Bhorophaginae 291
Biharisporites 88, 90
ellesmevensis 88
submamillaris 88
Borhyaenidae 253
Borissiakia 165, 225
betpakdalensis 226

Bostrychocevas 371-374

boulei 373

colubriformis 373

condamyt 373

elongatum 373

indicum 373

otsukat 373

polyplocum 371-373, 375, 395, 401, 404

saundersovum 373

SECOENSE 373
Brachycytheve 50

laticvistata 50, 77 ; Pl. 2, figs. 1-6

sphenordes 50, 76 ; Pl. 2, fig. 5
Brachycytheridae 50
Brachyelasma 421

duncani 415, 421

undulatum 421
Brachyphyllum 121
Brancoceratidae 337, 346
Brancoceratinae 337, 346, 347
Bryozoa 97
ButTLeER, P. M. 163-237
Bythocypris 46

vyeussiana 46, 75

stlicula 46
Bythocythere aliena 9
Bythocytheridae 9, 52

Calamospora 84.
Calamostachys 84
Calapoecia 423
Callopora 109
aspera 106
elegantula 109, 110
fletchevi 110
nana 109, 110
Campylocynodon 29%
Canidae 241, 288
Caninae 291
Canis 291
Canoidea 241, 288
Carcinodon 244
Carnivora 241, 243
Catentpova 424, 425, 427
Ruruensis 425
labyrinthica 425
obliqua 428
parallela 428
piirsaluensis 425
tapaensis 415, 416, 425, 426*, 427, 428; Pl.
Zrii az,
tvactabilis 428
wrighti 415, 426*, 427, 428 ; Pl. 2. figs. 7-11
Cateniporinae 424
Centrocythere 47
denticulata 47, 75 ; Pl. 1, figs. 8, 12, 13
Cephalogale 291
Ceramopora 99
imbricata 99
sp. 100); Ply i figs. 354
Ceramoporidae 99
Chalicothere 226

INDEX

Chalicotheres 165, 166
Chalicotheridae 226
Chalicotheriinae 166
Chalicotherium 165-167, 171, 173, 180, 184, 186*,
188, 196, 203*, 206, 207*, 213, 219, 222, 224,
225
anisodon 168, 169
antiquum 167, 168
baltavarense 193
baltavarensis 167, 168
brevivostris 165, 166, 172, 184, 193, 194, 195
goldfussi 165, 166, 167, 168, 169, 172, 175*,
180, 181, 183, 184, 187*, 188, 193, 203*
gvande 165-167, 168, 169-173, 175*, 180, 181,
183-185, 186*, 187*, 188, 191, 194*, 195,
196, 197*, 198, 199*, 200, 201, 202*, 203%,
204,205*, 206, 207*, 208, 210*, 211, 212*, 214,
216-220, 222, 223
grande rhodanicum 165-167, 170, 183, 185
magnum 169
var. secundarium 170
modicum 170, 224
pilgrimi 165, 167, 179, 175*, 180, 181, 186*,
187, 188, 194, 205*, 206, 212, 223
rusingense 165, 166, 173, 174, 175*, 176-178,
179*, 180-182, 183*, 184, 185, 186*, 187*, 188,
189*, 190, I9I, 192*, 193, 194*, 195*, 196.
TOW, UK), UCLh, Alo, Aoi, AOA, HOt", Zonk,
ZOD Pe ZOOM207~ 208,200) 2tOn, 2im 22,
Bip 2TA 20S S200, lin a2 On 220), 222),
223
salinum 165, 166, 171, 172, 180, 181, 186*, 223
sp. 165, 170
styviacum 165, 170
wetzlert 165, 166, 170, 171, 173, 185, 187, 188,
IQI, 196, 212, 223
Chalicotherium (Anisodon) 168
Chalicothevium (= Macrotherium) 165, 166
CHANDLER, M. E. J. 139-161
Choelichotherium 168
Chriacinae 243
Cirroceras 371, 372
depressum 373
Cladophlebis 133 ; Pl. 2, fig. 16
Coahuilites 395, 397, 403
Coccoserididae 415, 428
gen. et sp. indet. 428, 429 ; Pl. 3, figs. 1-6
Colpoclaenus 244
Constellariidae 107
Creodonta 241, 243, 246, 257
creodonts 242
Cryptostomata 96, 98, 113
Ctenostomata 96, 97
Cuanza basin 341, 342
Cyclogranisporites 88, 89, 90
lasius 88
Cyclostomata 96, 98
Cynodesmus 291
Cynodictis 291%
Cynodon 291
Cynohyaenodon 258
Cypridacea 9, 40

437

Cypridina 64

macrophthalma 64, 77

Cytheracea 9, 45
Cythere 43, 45-65, 68-70, 75-77

acanthoptera 52, 76
acutiloba 70,77
auriculata 6%
bairdiana 37,49, 75 ; Pl. 1, fig. 9
chelodon 49
concentrica 48
echinulata 65
filicostata 43, 64, 77
gaultina 68
gaultina excavata 69, 76
harvisiana O01, 75
harrisiana veticosa 61, 75
harrisiana setosa 61, 75
hilseana 45, 75
intervupta 61
Roninckiana 61, 76
laticristata 50, 77
lineatopunctata 61 ; Pl. 6, fig. 7
longispina 53, 76
lonsdaleiana 63, 67
macrophthalma 49
ornatissima 64
pedata 54
pedata laevis 55
phylloptera 5%
punctatula 47, 48, 75
quadrilaterata 61, 63
siliqua 43
slavantensis 48, 76
sphenoides 50
spinifera 45, 46, 76
subtuberculata 69, 76
triplicata 58
umbonata 52, 53, 75
umbonata acanthoptera 57
williamsoniana 75

var. gyanulosa 75

Cythereis 49, 51, 58, 62-68, 70, 75-77

acutiloba 70

alata 51, 75

auriculata 61, 75

bonnemai 66, 67

ciliata 65-68, 75

cornueli 63

cornuta 65-67, 75

corrigenda 62, 77 ; Pl. 7, figs. 6, 9

excavata 68, 69, 76

filicostata 63

folkstonensis 63, 66, 75 ; Pl. 7, figs. 1-5

gaultina 68, 75

glabrella 63, 66

hirsuta 68

icenica 49, 76

interrvupta 61, 75

longaeva longaeva 65, 66; Pl. 7, fig. 12;
Pl. 8, figs, 3, 5

lonsdaleiana 63, 67, 75,77 ; Pl. 7, figs. 7, 10

lurmannae 63, 66, 67, 76 ; Pl. 8, figs. 11-15

438 INDEX

Cythereis—cont. perforata 46
macrophthalma 49, 64, 75, 77; Pl. 6, figs. sevvata 74.
12-15, 17 umbonata 56
nuda 67, 75, 76; Pl. 7, figs. 11, 13, 16 Cytheroptera 56
ovnatissima 64, 65, 66, 68, 75 ; PI. 8, figs. 1, 2, umbonata 56
4, 6 Cytheropterina 24
altinodosa 66 plana 24, 25 ; Pl. 8, figs. 7-10 ; Pl. 9, figs. 1-4
nuda 65-67, 76 triebeli 25
paupera 66, 76 Cytheropteron 25, 47, 50, 51, 53-55
vadiata 66, 76 alatum cornuta 51, 76
reticulata 67, 76 fortis 51, 76
stricta 66 vobustum 51, 76
Phylloptera 5% concentyicum 47, 75
quadrilatevata 61, 63, 64, 75 cuspidatum 76
veticulata 63, 64, 66, 67, 68, 76; Pl. 8, figs montuosa 53, 76
16-19 tvicuspidata 56, 76
vudispinata 59, 62, 76, 77 hibernicum 51, 76
semiplicata 49, 64 pedatum 54, 76
spinicaudata 70, 76 salebrosa 54, 76
stvicta 67 phyllopterum 51, 76
thorenensis 66, 68, 75 ; Pl. 7, figs. 14, 15, 17 punctatula var. virginea 47
triplicata 58, 75 purum 25
lineata 58, 76 sherborni 55, 76
tuberosa 76 sphenoides 50, 76
var. symmetrica 76 umbonatum 56
vallata 76 umbonatum acanthoptera 76
wrightit 67, 75, 76; Pl. 7, fig. 8 umbonatum longispinata 56, 76
aculeata 76 Cytherura 54
Cytherella 70, 71 spoonert 54
chapmani 70, 76 Cytheruridea 24, 49
oblinquivugata 76
williamsoniana 74 Dalmanophyllum 422
bosqueti 71, 72, 77 subduplicatum 415,422; Pl. 1, figs. 16-18
granulosa 71 Daphoenodon 291
stricta 74 Daphoenus 289, 291
Cytherellidae 8, 70, 75 Daradiceras 395
Cytherelloidea 8, 70, 75 Dasuryodon 267
catenulata 8 Dechenella 319, 326, 332
chapmani 70, 71, 76 ; Pl. 9, figs. 15-19, 22 gigoutt 331-333
globosa 71 ; Pl. 9, figs. 7, 9, 10 vittbergensis 323, 324, 331-333
granulosa 71, 72, 75 ; Pl. 9, figs. 24-26 characters 324
hindei 72, 73 ; Pl. 9, figs. 4, 8, 11 trend 332
knaptonensis 71, 73, 77 ; Pl. 9, figs. 20, 21 setosa 319, 320, 321*, 322, 323, 324*, 325*, 326,
oblinquirugata 73, 76 ; Pl. 9, figs. 12, 13, 14 331-333
parawilliamsoni 7% styuvei 331
parawilliamsoniana 73, 77; Pl. 9, fig. 23 verneuilt 323, 324, 331-333
stricta 71,74, 75 ; Pl. 9, figs. 1-3, 5, 6 characters 324
wilwamsoniana 71-73, 75 trend 332
Cytheridea 9, 45, 46 Dechenella (Dechenella) setosa 319, 326—333 ; Pl.
bosquetiana 46 I, figs. 1-15
jonesiana 45, 46 Dechenella (Eudechenella) setosa 326
perforata 45, 75 Dechenellina 326
insignis 45, 46, 76 Deinotherium 310
votundata 45, 46, 76 . cuviert 310
subtrigona 22 hobleyi 310
vulsa 9 Delawarella subdelawarensis 402
Cytherideidae 14, 45 Deltatherium 245
Cytherideinae 14 Desmoceras
Cytherina 46, 47, 56 latidorvsatum 341, 343
ciliata 64 var. inflata 341, 343
concentrica 47 Desmoceratidae 338, 386

ornatissima 64, 77 Desmoceratinae 338, 388

INDEX 439

Desmophyllites 338, 339, 388
diphylloides 338, 388, 401, 402 ; Pl. 11, fig. 3
var. besairier 388
inermis 388
lata 388
Diastoporidae 98
Didymoceras 337, 338, 343, 371-374, 377, 380,
382, 384, 402, 404, 405
angolaense 337, 378, 381, 402 ; Pl. 8, fig. 2
californicum 337, 373, 376, 377, 405; Pl. 8,
fig. I
elongatum 376
fresnoense 380
hornbyense 337, 371, 372, 377, 383, 402, 405;
Pl. 8, fig. 4
kernense 381
NAVAYVOENSE 373
newtont 371
polyplocum 375-377
schloenbacht 373
SeCOENSE 377
sp. 378
stevensont, 373
subtuberculatum 337, 338, 371, 373, 374,
375, 376, 401, 402 ; Pl. 7, figs. 2-6
Didymoconus 246
Dinaelurus 303
Dinailurictis 303
Dinictis 303
Dinocyon 291
Diplomoceras 386
Diplomoceratidae 338, 385
Dipoloceras 347
Dissopsalis 242, 258, 262, 264, 265, 310-312
carnifex 265, 267, 310
pyroclasticus 241, 265, 266, 267, 309; Pl. 3
vubey 265
Dolocythere 14
maculosa 14
Dolocytheridea 20, 46
bosquetiana 20, 46, 47, 75, 76; Pl. 1, figs. 18,
19, 20
hilseana 46
intermedia 20
Douvilleicevas 337, 339, 342-344, 400
alternans 345
benonae 345
inaequinodum 345
magnodosum 345
mammillatum 344, 345
var. aequinodum 337, 343, 344, 345, 400;
Pl. 1, figs. 1-4
orbignyi 337, 345, 400 ; Pl. 1, fig. 5
Douvilleiceratidae 337, 343
Drymatophora problematica 96

Ektyphocythere 26
triangula 26, 27
Elobiceras 342, 400
Emperocevas 371, 380
simplicicostatum 371
Enhydra 257

Entalophora 99
Eocatenipora 428
Eocytheridea 16-22
carinata 18, 19; Pl. 4, figs. 6-11; Pl. 5,
figs. 1-8
elongata 19
faveolata 20, 21 ; Pl. 6, figs. 4-9
lacunosa 21
reticulata 2152275 Rl) 6; hess to; ors vel,
figs. I-5
Eocytheridea? 16-20
acuta 16, 17, 20; Pl. 3, figs. 11-14
astricta 17, 18, 20; Pl. 4, figs. 1-5
erugata 19, 20; Pl. 5, figs. 9-12; Pl. 6,
figs. I-3
Eofletcheria 424
Eofletcheriinae 423
Eomoropus 165, 196
Epiphylloceras 357
SUTYA 357
Eridotrypa 98, 102, 103, 104, 111, 112
cava 104 ; Pl. 2, figs. 5, 6
cylindrica 103 ; Pl. 2, figs. 3, 4
echinata 112
similis 103
Spy lod os.) bls 3) figs, 1, 2
styiata 110
umbonensis 105
Esthonia 429
astevisca 415, 429, 430 ; Pl. 3, figs. 9, Io
asteviscus 429
lamellosa 429
Eubaculites 366
Eucythere tyvigonalis 75
Euhyphantoceras maestrichtiense 376
Eulophoceras 396, 397
Eupachydiscus 338, 339, 389, 390
havadai 390
launayt 390
pseudogrossouvret 338, 389, 390, 401 ; Pl. 12,
figs. I, 4
var. undulatocostata 390
sp. 390
Eutrephoceras 338, 399
egitoense 399
simile 338, 399, 401
Exiteloceras bennisoni 380

Favositella 100
interpuncta 100
Favosites interpunctus 100
Felidae 241, 302
Felinae 302
Felis 304
leiodon 303, 304
Feloidea 241, 295
Fissipeda 241, 288
Fistulipora 101, 102
crassa 98, 101, 102 ; Pl. 1, fig. 5; Pl. 2, figs.
1
dobunica 102
lockportensis 102

440 INDEX

Fistulipova—contd.
ludensis 102
Fuhrbergiella 10, 11
avens 10
favosa to
minima 11 ; PI. 1, figs. 1-8

Galethylax 258
Gaudryceras 337, 338, 357, 360
aenigma 343, 358, 360
alamedense 360
analabense 362
beantalyense 362
cinctum 362
delvallense 362
demanense 362
densiplicatum 362
devallense 360
filicinctum 360
lauteli 362
mite 361, 362
navarrense 360-362
politissimum 358
propemite 362
sachalinense 360
sp. 361
striatum 362
var. pictum 362
tenuilivatum 362
vavagurense 337, 343, 301, 362, 401, 402; Pl.
File, nike, Gy 1edl, Gy aateey, a6,
variocostatum 362
vascogoticum 360
Gaudryceras (Neogaudryceras) pictum 361
Gaudryceratinae 337, 357
Geiselotherium 258, 262
Ginkgo 136
biloba 124, 134, 135
complex 124
huttoni 124
Ginkgoales 121, 122
Ginkgoites 121, 122, 124, 125, 131, 134
acosima 124
hermelini 125
longifolius 124
marginatus 125
obrutschewi 125
sibivica 125
taeniata 124, 131
ticoensis 121, 122, 123*, 124, 125, 131; Pl. 1,
figs. 5,6; Pl. 3, figs. 19-21 ; Pl. 4 fig. 27
tigrensis 121, 125, 126*, 127*, 128, 132*, 133,
resis Meh, we ae, art Sell, 3, tare veal PIL, 3}.
fig. 22 ; Pl. 4, figs. 23-26
Glyptoxoceras 386
Gomphotherium angustidens 310
Grangervia 213, 218
Grewinghia 420, 421
buceros 420
europaea 415, 416,420 ; Pl. 1, fig. 11
hibernica 415,420 ; Pl. 1, figs. 12-14
Hallopora 109, 111

Hallopora—cont.
elegantula 98, 109, 110 ; Pl. 4, figs. 3, 4
vamulosa 110
striata 98,110, 111 ; Pl. 4, figs. 5, 6
Halloporidae 109
Halysites catenularia 425, 426
escharoides 425
Halysitida 424, 425
Halysitidae 415, 424
Hamites vancouverensis 378, 380
Hamitidae 342, 400
Haplocytheridea jonesiana 45
Harpaleocyon 291
Hauericeras 389
Hauericeratinae 338, 389
Hecubides 242, 289, 291, 293, 295, 310, 311
americanus 289, 293, 295, 310
euryodon 241, 289, 290, 291, 292*, 293-295,
309 ; Pl. 5, fig. x
lemanensis 289, 293, 295, 310
macrodon 241, 289, 293, 294*, 295, 309 ;
IDE 5, wiles 2
Heliolites 429, 430 432
astevicus 429, 430
dubia 432
dubius 432
hirsutus 430
inordinata 429, 430
interstincta 429
intricatus var. lamellosa 429
parvistellus 429
Heliolitidae 415, 430
Heliolitoidea 415, 428, 430, 432, 433
Hemicyon 291
Hemigalinae 296
Hemipsalodon 267
Herpestes 296
Herpestinae 241, 296, 301, 311
Hesperocyon 291
Hetevoceras convadi 378, 380
hornbyense 377
Hetevopora crassa 101
Hewitson, W. 141, 142
Homocythere reticulata 61, 62
Homocytheridea 30
Hoplites 391-393
plasticus 391
(Hoplitoplacenticeras) plasticum 393
Vayt 392
var. marroti 392
Hoplitoplacenticervas 338, 339, 391, 401, 402
coesfieldensis 393
costulosum 338, 393, 401 ; Pl. 13, fig. 2
dolbergense 392
lafresnayanum 391, 393, 401
lemfordense 393
marroti 338, 391, 392, 401 ; Pl. 2, fig. 3; Pl.
13, fig. 3
var. Vari 392
plasticum 391, 393
plasticum costatum 392, 393
laeve 393

INDEX 441

Hoplitoplacenticeras—cont. Hysteroceras—cont.
praematura 392 varicosum 347, 350
spp. 338, 393, 394, 401 var. angolana 347, 350
vancouverense 391, 393
vari 391, 392, 401 Ictytocyon 293, 295
Howartu, M. K. 335-412 Imperatoria 258, 259
Hyaenaelurus 310 gallwitzi 258, 259
Hyaenodon 242, 263, 267, 270, 277, 278, 279, hagent 258
280, 286, 310, 311 Indoceras 395, 396
aimi 278, 280 Ischnognathus 258, 262
ambiguus 278, 280 Isocytheveis 66
andrewst 278, 280, 281, 283, 309, 310 fortinodis 66
aymardi 278, 280 Isohyaenodon 280, 281, 283, 284, 286
bavaricus 278, 280
brachycephalus 278, 280, 286, 287 Kayo, D. 413-434
brachyrhynchus 278, 280 Karkenia 121, 132-136
Cayluxi 278, 280 incurva 130*, 131*, 132*, 133-135; Pl. 1,
compressus 278, 280 fig. 10 ; Pl. 2, figs. 11-18 ; Pl. 5, figs. 29-32
crucians 278, 280 Kaye, P. 35-79
cruentus 278, 280 Kelba 242, 244, 246, 310, 311
dubius 278, 280 quadeemae 241, 244*, 245, 246, 309; PI. 1,
eminus 278, 280 fig. I
exiguus 278, 280 Kenophyllum 417
filholi 278, 280, 284 canaliferum 417
gevvaist 278, 280 inflatum 415,417, 418 ; Pl. 1, figs. 3-5
herberti 278, 280 silivicum 418
horridus 278-280 sp. 415, 417 ; Pl. 1, figs. 1, 2
lauvillardi 278, 280 subcylindricum 417
leptocephalus 278, 280 Kenya 165, 173, 242, 309
leptorhynchus 278, 280 National Museum 174
martini 278, 280 Kiaerophyllum anguineum 420
matthewi 278, 280, 309 Kichechia 242, 296, 301, 310, 311
milloquensis 278, 280 zamanae 241, 296, 297, 298, 299*, 300*, 301,
minor 278, 280, 281 302, 309; Pl. 5, fig. 3
minutus 278, 280 Kinkelinella bajociana 28
montanus 278, 280 tenuicostati 28
mustelinus 278-280, 284 Kirtonella 25, 26
parisiensis 278, 280 plicata 25, 26
paucidens 278, 280 reticulata 25, 26 ; Pl. 9, figs. 5-16; Pl. ro,
pervagus 278, 280 figs. I-2
pilgrimi 278, 280, 309 Kirtonellinae 25
vequient 278, 280 Kitchinites 338, 339, 386, 387
vetus 278, 280 angolaense 401, 402
vulpinus 278, 280 angolaensis 338, 339, 386, 387; Pl. 11,
yuanchensis 278, 280 figs. 4-6
Hyaenodon (Isohyaenodon) 287 brevicostata 387
andrewsi 241, 280, 281, 282*, 283, 284, 287 ; busnardot 387
Pl. 4, fig. 6 darwint 387
matthewi 241, 280, 283, 284*, 287 enayt 387
pilgrimi 241, 284, 285*, 286*, 287 fascigerus 387
Hyaenodontidae 241, 242, 246, 247, 257, 267 flabelliformis 387
Hyaenodontinae 241, 246, 258, 267, 277 pondicherryanus 387
Hyphantoceras 376 quadratus 387
buttense 376 sp. 387
cevatopse 376 KLAAMANN, E. 413-434
laqueum 376
vyeussianum 376 Leakitherium 242, 267, 276, 278
venustum 376 hiwe$i 241, 276, 277*, 278, 309 ; Pl. 4, figs. 4,
Hypophylloceras 357 5
Hysteroceras 342, 347, 348, 400 Ledoceras 342
binum 348 Leioclema 97, 98, 103, 105, 106, 107

orbignyt 347, 348 asperum 98, 106, 107 ; Pl. 3, figs. 5, 6

442

Leioclema—cont.
densiporum 105, 106 ; Pl. 3, figs. 3, 4
gvanatus 97
pulchellus 97
ramosum 107 ; Pl. 3, figs. 7, 8
Leiotriletes atavus 84.
nigvatus 84
Leonhardtina 258
Leptocyon 291
Leptocythere? 14
Leptopteris 141-143, 146-149, 151, 157, 159
superba 146
Libycoceras 343, 370, 394-396, 398, 405
acuto-dorsatum 394, 395
angolaense 397, 398
chargense 394, 395
Lichenariida 423
Limnocyonidae 246, 258
Limnocyoninae 246, 258
Lindstrémia subduplicata 422
Lioclema vamulosum 106, 107
Lophiodon goldfussi 167
Lophodentina 14
Loxolophus 245, 246
Lyoporidae 415, 423
Lytocevas (Gaudryceras) aureum 358
vavagurense 301

Machaeroidinae 246, 258
Machairodontinae 302
Machairodus parvulus 304
Macrocyprididae 42
Macrocypris 42
avcuala 43
concinna 75
equisita 42, 43, 76; Pl. 4, figs. 12, 16
muensteriana 43, 75 ; Pl. 4, figs. 9, 10
siliqua 43, 44, 75 ; Pl. 4, figs. 11, 14, 15, 18
simplex 44,75; Pl. 4, fig. 13
wrightit 44, 45,75; Pl. 4, fig. 17
Macrodentina sp. 49, 75
Macrotherium 166, 168, 172, 219
brevivostvis 172
giganteum 167-169
gvande 166, 169
var. vyhodanicum 170
magnum 169
oggenhausense 169
salinum 171
sansaniense 168, 169
sp. 172
wetzlevi 17%
Macrotherium (2) 192
Mammites 342
Mammocyon 291
Manambolites 338, 339, 395, 396-398, 403, 404

dandensis 338, 339, 396, 397, 398*, 402;

Vell ai, if, 3 1eNL, ang) ie
pervinquieri 397
piveleaut 397
YICENSIS 397, 404
spathi 397

INDEX

Manis gigantea 167
sindiense 172
sindiensis 171%

Mantelliceras 342

Maorites 389

Marsilea 88

Marsileaceae 85

Maw, G. 96

Menuites 343, 405

Mesocyon 291

Mesopuzosia 387
pacifica 387

Metachriacus 245

Metailurus 242, 302, 303, 304, 307, 311, 312

africanus 241, 304, 305, 306*, 307-310; Pl.

5, fig. 4
MAJOY 303-305, 307, 308
MINOY 303-305, 307, 308
mongoliensis 303-305, 307, 308
parvulus 303-305, 307, 308
tunggurensis 304
Metapterodon 242, 267, 268, 270, 272, 310
biinciswwus 271
Raiservi 241, 268, 269*, 271, 309 ; Pl. 4, fig. x

zadoki 241, 269*, 270, 271, 309 ; Pl. 4, fig. 2

Metaschizotherium 105, 169, 184, 223, 225
bavaricum 184, 224
fraasi 223-225
hennigi 226
tvansvaalensis 226, 234
Metasinopa 242, 258, 262-264, 310, 311
ethiopica 264
fraasi 263, 264
napaki 241, 263, 264*, 265, 309
sp. 264
Miacidae 301
Micropneumatocythere 11
convexa 11
globosa 12 ; Pl. 1, figs. 9-20
Mitoclema 98
regularis 99 ; Pl. 1, figs. 1, 2
Mitoclemella 99
Mocamedes basin 341, 342
Mongolia 172
Monoceratina 9, 52, 53-55
acanthoptera 52, 76 ; Pl. 3, fig. 2
bonnemai 52, 53, 76 ; Pl. 3, figs. 5, 6
laevoides 55, 77
longispina 52, 53, 77 ; Pl. 3, fig. 1
montuosa 53, 54, 56, 76; Pl. 3, fig. 3
pedata laevoides 55, 77 ; Pl. 3, fig. 17
pedata 54, 55-57, 70; Pl. 3, figs. 9-14
salebrosa 54, 55, 76; Pl. 3, figs. 15, 16
sherborni 55, 76 ; Pl. 3, fig. 4
tricuspidata 54, 56, 76; Pl. 3, figs. 7, 8

umbonata 54, 56, 57, 75, 76; Pl. 4, figs. 3, 4,

6-8
umbonatoides 55,57, 76 ; Pl. 4, figs. 2, 5
vulsa 9
Monotrypa 111, 112, 113
discoidea 112
flabellata 98, 112, 113 ; Pl. 6, figs. 1, 2

INDEX 443

Monotrypella 111, 112
benthallensis 111, 112 ; Pl. 5, figs. 1, 2
Monticulipora 112
sp. 96
Monticuliporidae 96
Moropus 168, 169, 198, 200, 213-215, 219, 224,
225
betpakdalensis 225
elatus 198, 201
matthewt 167
merviamt 167
Mortoniceras 342, 347, 400
Mortoniceras (Durnovarites) 347, 350, 352
crassicornutum 347
Mortoniceratinae 347
Mustela putorius 285, 280
Mzezzemceras 395, 397

Nautilidae 338, 399
Nautilus blanfordianus 399
Neocythere 47, 48
denticulata 47, 75 ; Pl. 1, figs. 8, 12, 13
vanveent 48, 75 ; Pl. 1, fig. 10
virginea 48, 75, 76; Pl. 1, figs. 11, 14-17
Neokentrocervas 337, 338, 342, 346, 347-349, 353,
354, 400
choffati 351, 352
var. cvassinoda 351, 352
costatum 351, 352
var. tenuis 353, 354
crassicostatum 337, 347, 355, 356, 400 ;
Pl. 2, fig. 16; Pl. 3, figs. 12-15
curvicornu 337, 340, 347, 348, 349, 359, 354,
400 ; Pl. 2, figs. 1-9
crassicorvnutum 347, 350
curvicornu 348
magnum 351, 352
pseudovaricosum 337, 347, 348, 353, 354-356,
400 ; Pl. 3, figs. 5-11
var. compressa 353
gracilis 354
singulave 337, 349, 350, 351, 354, 400; Pl. 2,
figs. 10-15
SP. 355
speciosum 348, 350
var. vudis 348
subtuberculatum 337, 351, 352, 353, 400 ; Pl. 3,
fig. I
tectovius 348
trituberculatum 337, 346, 350, 352, 400 ;
Pl. 3, figs. 2-4
Neophyllocevas 337, 339, 35, 357, 404
hetonaiense 357
lambertense 357
vamosum 357
ultimum 337, 356, 357, 402
Neopuzosia 387
ishikawai 387
japonica 387
matsumotoi 387
Nestoritherium 165
simense 181

Nestoritherium—cont.
sivalense 193
Nicholsonella 107-109
florida 108
parva 108, 109 ; Pl. 4, figs. 1, 2
vinguebergi 109
Nicholsonia megastoma 430
Nimraivides 303
Nimravinae 241, 302, 303
Nimravus 302, 303
Nostoceras 338, 339, 342, 343, 371-374, 377, 378;
379*, 380-382, 384, 402, 404, 405
angolaense 378, 383
avaconts 371, 381, 384
helicinum 338, 377, 383, 402, 403 ; Pl. 8, figs.
3,5
var. cvassum 383
humile 383, 384
hornbyense 377
hyatti 338, 371, 378, 379*, 380, 382, 383, 402,
Mos) = Il, G) A IZAl; We), wiles, a
kernense 338, 381, 402 ; Pl. 8, fig. 6
mariateresianum 383
mexicanum 381
natalense 384
obtusum 338, 339, 379*, 384, 402 ; Pl. ro, fig. 2
pauper 374
rotundum 338, 339, 381, 382, 383, 402; Pl.
10, fig. 3
schloenbacht 374
sp. 378
stantoni 374, 383
sternbergi 380, 381
subangulatum 374
Nostoceratidae 337, 371
Nothocyon 291

Octocyoninae 291
Oiophyllites 338, 339, 389
angolaense 401
angolensis 338, 389, 402
decipiens 389, 402
Olduvai 226, 232, 233
Opsiclaenodon 243
Orthonotacythere voigteiensis 30
Osmunda 141-143, 146-149, 151, 156-161
banksiaefolia 158, 159
bromeliaefolia 158, 159
japonica 147
javanicum 158, 159
lancea 140, 147, 159
lignitum 141, 158-160
vegalis 147, 148
vachellit 159
zeylanica 156*
Osmunda (Plenasium) 160
banksiaefolia 146-148
bromeliaefolia 148
dowkeri 142, 158, 160
javanicum 148
lignitum 158
vachellii 148

444 INDEX

Osmundaceae 141, 142
Osmundastrum 142, 143, 146-149, 159
cinnamomea 159
claytoniana 159
Osmundites 141-161
chandlevi 142, 157, 158, 160
dowkeri 141-161 ; Pls. 1-12, 24 figs.
Owen, D. E. 93-117
Oxyaenidae 246, 247, 253, 257
Oxyaenoid creodonts 242
Oxyaenoidea 241, 246, 257
Oxyclaeninae 241, 243, 244

Pachycynodon 291%
Pachydictya 114
crassa 98, 115; Pl. 5, figs. 6-8
dichotoma 115
holmi 115
Pachydiscidae 338, 389
Pachydiscus grossouvret 389
neubergicus 404
Paciceras 394, 396
Palaeohalysites kuvuensis 425
pursaluensis 425
tapaensis 425
Palaeothevium 171
cvassum 171
magnum 171
schinzit 170, 171, 194*
Pangolin gigantesque 167
Pavacynodon 291
Paracynohyaenodon 258, 202
Paracyprididae 9
Paracypris 9
bajociana 9
Paradoxurinae 296
Paralenticeras 397
Parapachydiscus besairiei 389
Parictis 291
Paroxyclaenus 243
Perissodactyls 188
Petraia inflata 418
subduplicata 422
Pettitt, J. M. 81-92
Phoberocyon 291
Pholadomya beds 400
Phylloceratidae 337, 356
Phylloptychoceras 386
sipho 386 ; Pl. 11, fig. 1
sp. 385
Phyllotillon 165, 171, 184, 193, 198, 214, 219, 224,
225, 226
betpakdalensis 165, 174, 198, 223, 224, 225
NAVICUS 173, 223-225
Physocythere 75
virginea 48, 75, 76; Pl. i, figs. 11, 14-17
Placenticeras 342
veinecket 342
Placenticeratidae 338, 391
Plagiolophus annectens 217*
Plasmopova conferta 432
Platycopina 8, 70

Platycythereis 68
chapmani 69, 76 ; Pl. 6, figs. 16, 18, 20
excavata 69
gaultina 68, 75, 70; Pl. 8, fig. 9
laminata 69, 77 ; Pl. 6, fig. 19
Plenastum 141, 142, 143, 146-149, 157-160
Plesiocyon 291
Pleurocythere 14
kivtonensis 14
nodosa 14
Pleurocytherinae 14
Pliocyon 291
Plithocyon 29%
Pneumatocythere 13, 14
bajociana 13, 14
carinata 13, 14 ; Pl. 2, figs. 1-9
Podocopida 8, 42
Podocopina 42
Pogonodon 303
Polypova problematica 96
Polyptychoceras 338, 339, 385, 386, 403
havadanum 385
obliquecostatum 385
obstrictum 385
pseudogaultianum 338, 385, 386, 401, 402, 404 ;
TEAL, eit, aay,
subquadrvatum 385
subundulatum 385
vancouverense 385
Polyzoa 97
Pontocyprella 47
harvisiana 47, 75
triquetva 46, 75
Pontocypris 46
bosquetiana 46, 75
trigonalis 75
Portrane limestone 415-434
Praefuhrbergiella 10, 11
avens 10
favosa 10
minima 11 ; Pl. 1, figs. 1-8
Praeschuleridea 22
subtrigona 22
magna 23, 24; Pl. 7, figs. 6-11; Pl. 8,
figs. 1-6
subtrigona 22
ventviosa 24
angulata 24
ventviosa 24
Pragnellia 430
avborescens 415, 430 ; Pl. 3, figs. 7, 8
Prionocyclus 342
Proamphicyon 291
Procytheridea triangula 26
ventyiosa 24
Procytheropteron 48
virgineum 48
Prodissopsalis 258, 259, 204
eocaentcus 259
Proetidae 326
Progonocythere 9
cristata 9, 1o

Progonocytheridae 9, 47
Progonocytherinae 9
Progymnospermopsida 86
Proheliolites 432
dubius 415, 416,432 ; Pl. 4, figs. 10-12
Proheliolitidae 415, 432
Prolimnocyon 246
Propora hirsuta 430
Proporida 432
Propterodon 267, 279
Prorhyzaena 258
Protaraeida 428
Prothryptacodon 244
Protoacanthocythere 10
faveolata to
Protobarinophyton 86
obrutschevii 86
Protocythere 57
auriculata 61, 62
consobrina 57, 58, 77 ; Pl. 5, figs. 17-19
jonest 58, 76
lineata 58, 59, 75-77; Pl. 5, figs. 1-8
vudispinata 59, 60, 76; Pl. 5, figs. g-11
tricostata 59, 76, 77 ; Pl. 5, figs. 14, 16
triebeli 61, 62, 76
triplicata 58 ; Pl. 5, figs. 12, 13, 15
Protocytheridae 25, 57
Proviverra 258, 262
Proviverrinae 241, 246, 253, 258
Pseudaelurinae 302
Pseudaelurus 302, 303, 307, 311
africanus 303, 304
ailuroides 307
intvepidus 307
kansensis 307
lortett 307
mayint 307
marshi 307
martint 307
pedionomus 307
quadridentatus 307
thinobates 303
tournauensis 307
transitovius 307
Pseudamphicyon 291
Pseudocreodi 246, 257
Pseudocythere 47
simplex 47, 76
Pseudokossmaticeras paulcki 391
Pseudophyllites 357, 359
indva 359
SP. 359
Psilophyton 84, 88
princeps 84
Pteridophyta 83

Pterodon 242, 263, 267, 270, 272, 278, 309, 311
africanus 241, 267, 272, 273*, 274-276, 309,

BLor, PIE fies 3
biincisivius 268
californicus 272
coquandi 272
cuviert 272

INDEX

Ptervodon—cont.
dasyuroides 268, 272
grandis 272, 274
hyaenoides 272
leptognathus 272
magnus 272
nyanzae 241, 272, 274, 275*, 276, 309
parisiensis 272
phiomensis 272
Pterygocythereis 51
phylloptera 5%
Ptilophyllum 121
Ptychoceras pseudogaultianum 385
Puzosia 342, 400
lytoceroides 343, 361
Puzosiinae 338, 386

Quepora 427, 428
aequabilis 427, 428
agglomeratiformis 428
delicatula 428
pavallela 427, 428
quebecensis 427, 428
Quercytherium 252, 310, 311
tenebrosum 247

Reuschia 423, 424

aperta 424

Sp. 415,423,424 ; Pl. 2, figs. 5, 6
Rhabdomesidae 113
Rhinidictyidae 114
Rhombopora 113

mawi 113, 144 ; Pl. 5, figs. 3-5
Romaniceras 342
Rugosa 415, 416, 417, 418

Sarcinula 415, 422, 423
latum 423
luhai 423
organum 423
sp. 422 ; Pl. 2, figs. 1-4
Sarcinulida 422
SAVAGE, R. J. G. 239-316
Schizotheriinae 222
Schizotherium 167, 171, 173, 184, 188, 191,

196, 198, 206, 208, 213, 214, 218, 219, 221—

225
avitum 191, 193, 196
pilgrimi 173
priscum 167, 170, 171, 173, 175*, 180,
183-185, 188, 191, 193, 194, 200, 201,
ZOOS ZTON 2m ed ely 2 OM aes
222, 224
sp. 173, 196, 200
turgaicum 167, 172, 180, 188, 201, 204,
208, 213, 214, 216, 220, 222, 224
wetzlevi 171
Schloenbachia lenzi 351
Schuleridea 45
jonesiana 45, 46, 75, 76; Pl. 1, figs. 1-5
Schulerideidae 15
Schulerideinae 15
Scutellum 325

445

194,
223,

181,
206,
220,

206,

446 INDEX

Scutellum (Scutellum) flabelliferum 324, 325
Selaginella 90
eggersit 9o
vadiata 90
SELWOOD, E. B. 317-333
Sharpeiceras goliath 342
Sheffield Museum 97
Sinopa 253, 258, 259, 262-264, 310, 311
ethiopica 263
grangervi 259
Solenoceras 343, 402-405
bembense 402
binodosa 402
Sp. 402
Southcavea 27
bajociana 27, 28, 29
grandis 27, 29; Pl. 11, figs. 5-13; Pl. 12,
fig. I
reticulata 27, 28, 29 ; Pl. io, figs. 3-14 ; Pl.
II, figs. 1-4
Spanoxyodon 244
Spathiceras 347
Sphenodiscidae 398*
Sphenodiscus 338, 339, 394, 395, 396, 398, 399,
403, 404
lobatus 399
pleurisepta 395, 398*
siva 399
Sp. 338, 396, 397, 398*, 402
ubaghsi 403
Sphenopteris 133
Spivopora 99
Sporogonites 90
exubevans 90
Stenoplesictinae 296, 301
Stictopova cvassa 115
Stoliczkaia 342
dispar 401
Streptelasma 418, 420
bystrowt 418
corniculum 419
craigense 420
distinctum 415, 418, 419 ; Pl. 1, figs. 8,9
euvopaeum 420
fragile 415, 418 ; Pl. 1, figs. 6, 7
orientale 419
poulsent 419
vusticum 415, 419, 420 ; Pl. 1, fig. 10
Streptelasma (Grewingkia) europaeum euvopaeum
420
(Kiaerophyllum) europaeum 420
Streptelasmatidae 415, 417
Stringocephalus burtini 324
Subprionocyclus 342
Subptychoceras 386
Svalbardia polymorpha 88, 90
Syringophyllidae 415, 422
Syrvingophyllum organum 423

Systenocythere 29, 30
extlofasciata 29, 30
sp. 30 ; Pl. 12, figs. 2-5

Tabulata 415, 422, 433
Tanganyika 165, 226
Tephrocyon 291
Teratodon 242, 247, 250, 252, 253, 255, 310, 311
enigmae 241, 253, 254*, 255*, 256*, 257, 309 ;
Pl. 1, figs. 4, 5
spekei 241, 247, 248*, 249*, 250, 251*, 253,
255, 257, 309; Pl. 1, figs. 2, 3
Teratodontidae 241, 246, 247
Tetragonites 339, 401, 402
epigonus 343
jurinianus angolana 343
Tetragonitidae 337, 357
Texanites 342
Thamniscus problematica 96
Tickwood Beds 98
Ticéd Amphitheatre 121, 124
Todea 141-143, 146-149, 151, 156, 157, 159
barbara 148, 156*
barnea 1.43
Tomarctus 291
Trachyleberidea 70
acutiloba 70, 76, 77 ; Pl. 8, figs. 7, 8, 10
Trachyleberididae 62
Trematopora striata 110
Trepostomata 96, 98, 102
Tricentes 245, 246
Trichopitys 135, 136
heteromorpha 135
Triisodontinae 243
Trileites langi 84
Tritemnodon 258, 262, 263, 310
Turrilites helicinus 383

polyplocus 372
SAXONICUS 372

Uganda 232, 242, 309

Veenia 60, 62
barringtonensis 60, 77 ; Pl. 6, figs. 1, 2, 3
harrisiana 60, 61, 62, 63, 66, 75-77; Pl. 4

fig. 1; Pl. 6, figs. q—11

triebeli 61

VINE, G. R. 96-97

Vishnucyon 293

Viverravinae 296, 301

Viverridae 241, 295, 296

Viverrinae 296, 301

Vulpes 291

Welsh National Museum 97

Wormispora 430, 432
hirsuta 415,430, 431, 432; Pl. 4, figs. 1-3
portranensis 415,431, 432 ; Pl. 4, figs. 4-9

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