CHAPTER III
SiSTEMATIC DESCRIPTION CIUPTER III
systematic description
Section I : Mortonlceratinae
Introduction : The ammonoid species described by
Stoliczka under the group of Ammonites crlstatl were sub
divided by him into species 1, Ammonites blanfordianus,
2, Ammonites inflatus, condollianus. ootatoorensis and
corruptus, 3, Amnionites propinquus. 4. Ammonites obesus,
5. Ammonites se rratocarlnatus. 6, Ammonite s subtricarinatus.
These were transferred by later workers e.g. Kossmat to
Schloenbachia and its subgenera as : Schloenbachla
(Tropitoldes) . S. (Prlnotropis) . S. (Peroniceras).
S, (Munerlceras) etc.
According to present ideas the above mentioned species
have undergone further transfers and except those of the
Inflata group, are placed under different subfamilies, viz.
Peroniceratlnae, Mune rice rat inae, etc. These species are,
therefore, not considered under the present section; but those
of the Inflata group which are now found to belong to the sub
family Mortonlceratinae are dealt with here.
The species which represent this subfamily in the present collection, viz. Mortoniceras (Mortoniceras) inflatum (Sow.);
M. (M.) rostratum (Sow.), Mortonioeras (Peiradoceras) indicum
spo nov., M. (Purnovarites) perinflatum Spath., M. (p.)
- 17 - - 18 -
subquadratum Spath, M. (d .) sp. Indet; ?Mortonicera8
(?Mortoniceras) deshpandel sp, nov., Prohysteroceras
(Goodhallltes) stoliczkal sp. nov. are dealt with here., Of these eight species Mortonlceras (Mortonlceras) inflatum was described by Stoliczka and Kossmat from these rocks.
Three species viz. Mortoniceras (M.) rostratum (Sow.),
M. (Durnovarites) perlnflatum Spath., M. (D .) subquadratum
Spath. are species already known and are recorded from outside
South Indian basin; they are now recorded here for the first time. The remaining species described here are new to science.
The subfamily Mortoniceratinae has an interesting history, being used in the first instance by Spath (1925) to comprise species of texanum group of Senonian. Workers have differed on the position of Ammonites vespertinus Morton, the genotype of Mortoniceras, and its exact horizon was also doubtful.
Adkins in 1928, however, established its horizon as Albian, and hence it was grouped with other related ammonoids which were included in Inflacticeratidae of Spath (1925) by some, and by others in Pervinquieridae of Spath (l926). Later,
Spath (1932) proposed a new name, Texanites for the
Mortoniceras like Senonian forms of the texanum group which were included in Peroniceratidae Hyatt. - 19 -
This confusion regarding Mortonlceras was partly due to the doubtful or wrongly assigned horizon to Ammonites vespertlnus Morton, and partly due to the homeomorphy between
the Alblan and Senonlan forms. According to the taxonomic
standards then current this group of fossils was as mentioned earlier, once placed under Schloenbachla by Kossmat (1897) and many others. Wright (1957) while diagnosing this subfamily remarks " As the synonymies of the subfamily and its genera
show, both the nomenclature and scale of classification of
the group have been in doubt. A large number of species with much the same basic characters vary in the combination of nature of whorl section, number and shape of tubercles, and strength and direction of ribs ...... (p. L405), but time may justify recognition of some genera and subgenera here reduced
to synonyms ” .
The material at our disposal, however, at present is insufficient to make an attempt at any thing of such a classification; hence for the present we have adopted the various genera and subgenera as accepted in the Treatise .
Phylum : Mollusca
Class : Cephalopoda
Order ; Ammonoidea
Sub-order : Ammonitlna - 20 -
Super family : Acanthocerataceae Ityatt, 1900
Family : Brancoceratldae Spath, 1933
Sub family ; Mortoniceratinae Spath, 1925
Genus : Mortonleeraa Meek, 1876
Sub-genus : Deiradoceras Van Hoepen, 1931
Mortoniceras (Deiradoceras) indicum sp, nov.
PI. I, Figs. 1, 3
Material : One specimen, Holotype Ut l/70
Dimensions; Breadth of whorl section : 58 mm
Height of whorl section ; 62 mm
B / H =0.93
Description : The present material is fragmentary only the body chamber being preserved. The shell is in general compressed with height almost equal to or a little greater than the breadth of the whorl section. The sides are slightly convex. The venter is fairly broad with a strong and high median keel. The ribs are single, broad, low, prorsiradiate and weak. Each rib has very weakly developed bulloid umbilical tubercle, only one row of ventrolateral tubercles which are strong and clavate and almost vertical (i.e. parallel to the plane of coiling). There are no lateral tubercles. - 21 -
Remarks ; Though the present material is only fragmentary still it provides details which help to distinguish it from
any of the known comparable species. It is placed in
Mortoniceras (Deiradoceras) because of strong ventral keel and the nature of ribbing and the tubercles. The present species is comparable to Ammonites inflatus Sow. var. I
Stoliczka (Stoliczka, 1865, p. 48, pi. 27, fig, 1, la, lb)
from Utatur group at Utatur and Odium, but can be distinguished
from it by much feebler ornament, absence of lateral tubercles and presence of strongly clavate ventro-lateral tubercles which are oriented vertically.
The present species may be compared with M. (d .) bipunctatum Spath (Spath, 1931, p. 422-24, pi. XLV, figs.
2a, b; text fig. 145 c, 146) from Upper Gault (Orbignyi and
Varicosum - sub zone) England, but differs in having stronger clavate ventrolateral tubercles and prorsiradiate, low, rounded ribs. The low rounded character of ribs is seen also in
M. (D.) albense Spath (Spath, 1931, p. 424, pi. XLIII, fig. 2, pi. XLIV, fig. 4) from Orbignyi and Varicosum sub zone of
England which, however, does not show sharp clavate ventro
lateral tubercles which are parallel to the plane of coiling of the shell and thus is easily distinguished from the present
speci es.
Occurrence : White clays from Mortoniceras inflatum zone near
Utatur. - 22 -
Subgenus : Mortonlceras Meek, 1876
Mortonlceras (Mortonlceras) Inflatum ( Sowerby )
PI. I, Figs. 2, 4
1818 Amraonltes Inflatus Sowerby : Sowerby, p. 170, pi. 178
1868 -Amnionltes rostratus Sowerby; Stoliczka, p. 53
1897 Schloenbachla inflate (Sowerty) : Kossmat, p. 185 (parts)
1899 Schloenbachia inflata (Sowerby) : V, Popovici-Hatzeg, p.17
1930 Infla^ticeras aequatoralis (Kossmat) : Besairie, p. 630.
1930 Pervinquleria aequatoralis (Kossmat) : Spath, p. 64
1931 Mortoniceras (Pervinquleria) inflatum (Sowerby): Spath,
p. 381, text fig. 128
1931 Mortoniceras (Pervinquleria) rostratum (Sowerby) : Spath, p. 399, text fig. 136
1968 Schloenbachla inflata (Sowerby) ; Sastry, Rao and Mamgain, pi. 1, figs. 1 and 2.
Material : Several specimens, Plesiotype Ut 44/70
Dimensions; Width of whorl section : 78 mm
Height of whorl section; 78 mm
B / H =1.0 only Ftemarks : The Piesiotype is a fragment representing the|^body chamber as it does not show any suture. It is identified with the Sowerby’s species Inflatum as it shows all essential characters of the species, such as a squarish cross section with a rounded intercostal cross section, an arched venter with a rounded strong keel; simple broad, slightly prorsiradiat< - 23 -
moderately strong ribs which are separated by wider inter spaces; each rib bearing a bulloid, low and elongated umbilical tubercle, a mediolateral and a strong conical ventrolateral tubercle; pointing almost vertically to the plane of colling; the ribs almost stop at the ventrolateral tubercles and give only faint indication of their oblique continuation towards the ventral keel. Stoliczka has reported this species from the Lower Utatur near Utatur.
Occurrence : Gypseous clays of Mortoniceras inflatum zone near Utatur.
Distribution ; This species is widely recorded from Upper
Alblan of Europe, Africa, North America, South America and
Pakistan (Samana Range).
Mortoniceras (Mortoniceras) rostratum (Sowerby)
PI. II, Figs. 3, 4
1817 Ammonites rostratus Sowerby ; Sowerby, p. 163, pi. clxxlli
1849 Ammonites rostratus Sowerby : Brown, pi. 19, fig. 10
1921 Subschloenbachia gostrata (Sowerby) : Spath, p. 284
1922 Inflactlceras (subschloenbachia) rostratum (Sowerby) : Spath, p. 100
1930 Mortoniceras (Pervinquleria) rostratum (Sowerby) : Spath, p. 400, pi. 36, fig. 6; pi. 38, fig. 4; pi. 39, figs. 4a,b; pi. 40, figs. la,b, 7a,b; pi.42, fig. 2; text figs. 130 f, 136, 137e - 24 -
Material : One specimen Ut 68/70
Remarks : The present material is a fragment of the body chamber with part of the rostrum preserved but the umbilical wall is not wholly preserved. The cross section is somewhat rounded and depressed, with maximum width near the umbilical margins; venter comparatively narrow with a strong, high median keel; the anterior part of the shell is curved up and projected up Into a rostrum. Ornamentation consists of simple, recti- radiate ribs stopping at the ventrolateral tubercles separated by interspaces about 3 to 4 times wider than ribs. Each rib with a faint umbilical bulla, a slightly stronger bulloid lateral tubercle and a very strong ventrolateral tubercle. The ventrolateral tubercles on the two sides make an acute angle between themselves and pointing obliquely away from equitorial plane of the shell. Though our material shows a depressed cross- section other characters as described above even in its conditioi leads us to recognize it as Mortoniceras (Mortonioeras) rostraturn (Sowerby) (Spath, 1930, p. 400, text fig, 136) from
Upper Albian (Substuderi-and dispar- sub zones) of Surrey,
Hampshire, Oxfordshire, etc, England,
In recent years workers, like Kennddy (1970), have combined this species with M, (M.) infl atum (Sowerby); but it can be separated by its different ornament.
Occurrence : White gypseous clays of Mortoniceras inflatum zone near Utatur. - 25 -
Distribution : This species is very widely distributed in the
Upper Albian rocks of England, N. America, Madagascar, Angola,
Natal and Zululand, etc. in association with M. (M,) inflatum
(Sowerby).
? Mortoniceras (? Mortoniceras) deshpandei sp. nov.
PI. II, Figs. 1, 2
Material : One specimen, Holotype Kn 92/70
Dimensions; Diameter of shell : 81 mm (l)
Breadth of whorl section:36.5 mm (0.45)
Height of whorl section :34.0 mm (0.42)
Umbilical diameter :34.5 mm (0.43)
Breadth of whorl section at i whorl :23.0 mm (0,28)
Height of whorl section at ^ whorl :23.0 mm (0.28)
B/H=1,0, B/Hati whorl = 1.0
Description : The present specimen is slightly broken. It is septate and of moderate size. The shell is evolute, rather slander with weakly convex sides and a somewhat squarish cross section. The intercostal section is almost square with rounded corners. The almost flat venter has a broad rounded moderately strong median keel. The umbilical as well as ventrolateral shoulders are well formed and rounded. The umbilical wall is steep. - 26 - '
The ornamentation consists of ribs and tubercles. The tubercles are dominant over ribs. The ribs are flat, low and
Inconspicuous and are discemable only because of the tubercles they bear. All the ribs are rectiradiate, single and almost terminate on the outer ventrolateral tubercles; they show a tendency to become sparser in the later stages of shell growth.
The interspaces are very much broader than the ribs at all stages of shell growth. Each rib bears 3 tubercles on each side, one lateral placed slightly below mid’ Side, and two ventrolaterals placed rather close together. All the tubercles have a round base and are blunt at the apex.
There are indications of presence of constrictions after every rib seen better on the venter than on the sides where they appear to become weaker; as some of the portions of shall are eroded, it can not be said with certainty if these constrictions have any regularity in spacing.
The suture is Mortoniceras type. The first lateral saddle is massive, rectangular, bifid and largest. The first lateral lobe is comparatively narrow, deep and trifid. The second lateral saddle is also bifid but much more slender than the first lateral saddle. The subsequent lobe almost reaches the umbilical seam.
Remarks : Its sutural pattern shows that it falls in
Acanthocerataceae, its well rounded, strong ventral keel is like that of Mortoniceras. Tubercles dominant over ribs - 27 -
coupled with ventral o> nstrictions is the character found
in Euoaijhaloceras Spath. Its ventral keel, strong and well
rounded, shotvs that it cannot possibly belong to any of the
later Aoanthoceratld subfamilies like Collignoniceratiuae
Khere the keel is serrate.
The nearest approach may be considered to the Upper
iMbian Mortoniccxiis (M.) inflatua (So w .); but from that also
it differs in several res{>ects like absence of umbilical
tubercles, ribs simple and unbranched at all stages of shell
^otfth and ventral constrictions.
This specimen ij^ay represent a stage between Mortonicerag
(Mortoniceras) and Fiuonphaloceras or it could represent a
modification of Mortoniceras Stalk which could not develop l i i H O -ftrni iJihicU />e ir a c < -J -fouy>J i>i t h i^ • further and came to an end./^ Flirther, the present specimen comes
from Mantelliceras tuberculatum zone i.e. a stratigraphic
horizon higher than that of M, (W.) inflatun.
Euomphaloceras Spath is considered to have evolved out
of Acant hoc eras and to range from Middle Cenoinanian to Upper
Cen(Mt£aiian; but the present specimen comes from a slightly
old er horizon and is accompanied by Mantsllloeras. This may
imply that Euomphalooerus tendency had appeared earlier than
it is supi>osed to have done. - 28 -
Thus while its generic position is somewhat uncertain, being apparently more Mortoniceras than Euomphaloceras. its
distinctness as a species is clear and definite as compared
to anything known from South India and also from elsewhere.
Occurren ce : Yellowish sandy limestone from Mantelliceras tuberculatum zone near Kunnam.
Subgenus : Dumovarites Spath
Mortoniceras (Dumovarites' ? perinflatum Spath
PI. Ill, Figs. 1, 2
1860 Amaonites inflatus Sowerby ; Pictet and Campiche, p.178, pi. xxii, figs. 3a,b only.
1922 Inflacticeras (Subschloenbachia) perinflatum Spath : Spath, p. 113.
1925 Inflacticeras inflatum (Sowerby) : Diener, p. 137
1931 Mortoniceras (Dumovarites) perinflatum (Spath): Spath, p. 430, pi. XL, fig. 2, text fig. 150
Material : One specimen, Plesiotype Ut 30/70
Dimensions : Diameter of shell : 91 mm (l )
Breadth of whorl section; 58 mm (0.63)
Height of whorl section : 43 mui (0.47)
Umbilical diameter : 22 mm (0.23)
B / H = 1.34
Description : The shell is depressed with breadth of the whoirl
section much greater than the height. The present specimen is a - 29 - ( little deformed but the depressed nature can easily be made out. The shell Is fairly involute, the venter is broad and almost flat to slightly arched. The median keel is thin and somewhat sharp. The ornamentation consists of strong ribs which are alternately long and short; at tue umbilicus, they are rursiradiate but on the sides, they curve and on ventro lateral shoulder, they become prorsiradiate, making an acute angle with the median keel, which, however, they do not reach.
Every long rib has 4 tubercles, umbilical one is often bulloid and not well developed, lateral tuberclet and i ventrolateral tubercles. The outer ventrolateral tubercle is strongest but shows weakening at later stages of growth of the shell. The suture is Mortoniceras type with c massive bifid first lateral saddle and a little less broad first lateral lobe which is asymmetrically bifid.
Remaites : The present material is unique to South Indian basin and can be distinguished easily from all other so far described forms of Mortoniceras by its tumidity and strongly curved ribs.
It is assigned to Durnovarites as it has four rows of tubercles on each rib on each side.
The present material resembles Mortoniceras (Pumovarites) perinflatum Spath (Spath, 1931, p. 430, pi. XL, fig. 2, text fig. 150) from the Upper Albian of England in most respects except that our specimen shows strongly curved prorsiradiate ribs. As the present material is slightly deformed, it is for - 30 - the present idaitlfied with Spath's well known species
M. (D.) perlnflatum. Better preserved material, however, may show that this belongs to a species distinct from tuti. allied to M, (D.) perinflatum Spath.
Occurrence : Ochre clays of Mortoniceras inflatum zone near
Utatur.
Distribution : This species is widely distributed in the Upper most Albian being known from Angola, England, France,
Madagascar, etc.
Mortoniceras (Purnovarites) subquadratum Spath
PI. Ill, Figs. 3, 4 Sio\- 71865 Ammonites inflatus ^on Sbwerfey^ : Stoliczka, p. 48, PI. XXVII, figs. 1, la,b,c
1931 Mortoniceras (Purnovarites) subquadratum Spath : Spath, p. 435, pi. 37, figs. 6a,b; pi. 42, figs. 5, 9a,b; pi. 43, figs. 7a,b; pi. 44, fig. 6; pi. 45, fig. 5, pi. 47, figs. 2-4; pi. 48, figs. 2, 4.
Material ; Several specimens, Lectotype Ut 38/70
Dimenslons : Diameter of shell : 77 mm (l) Breadth of whorl section:37 mm (0.4S) Height of whorl section: 35 mm (0.45) Umbilical diameter : 29 mm (0.38) B / H = 1.05 - 31 -
Remarks : The present material consists of several specimens fragmentary but otherwise well preserved and allows specific identification. The evolute, compressed shell with venter slightly arched to almost flatji sides flat; whorl section squarish tending to become slightly trapezoid in the later growth stages; umbilicus large and moderately deep with steep walls; ventral keel fairly sharp though not high; ribs characteristically branching in the early stages soon changing to alternatingly long and short, rectiradiate on early whorls becoming sinuous later, each long rib carrying four tubercles on each side; umbilical tubercle tending to shift away from the umbilical wall on the later stages of growth, i'he ventrolateral tubercles well separated and spinose in early stages, tending to fuse on later stages of grov?th and ventral tubercles showing spiral striation on later stages of growth. The present material has the above characters which help in identifying it with
Mortoniceras (Purnovarites) subquadratum Spath (Spath, 1931, p. 435, pi. 37, figs. 6a,b; pi. 42, figs, 5, 9a,b; pi. 43, figs. 7a,b; pi. 44, fig. 6; pi. 45, fig. 5; pi. 47, figs. 2-4; pi. 48, figs. 2-4) from the Upper most Albian (dispar-perinflatum subzone) from England and also reported by Stoliczka (1865, p. 48, pi. 27, figs. 1, la, b, c) from Utatur group near Odium.
As ouV material is all in fragments small differences in dimensions are overlooked for the present. It m£y, however, be mentioned that in general our material seems to be intermediate - 32 - between Mortoniceras (Purnovarltes) quadratum Spath and
M. (d .) subquadratum Spath and more material may prove that the two species are one and the same.
Occurrence : Gypseous clays from Mortoniceras inflatum zone near Utatur and Maravattur.
Distrlbution : This species is widely recorded coming from
Upper most Albian of England, North America, Nigeria,
Madagascar, Angola, etc.
Mortonic eras (Purnovarlte s) sp. indet
PI. IV, Fig. 4
Material : One fragment, Ut 33/70
Description : The present material is fragmentary with only one side of a small portion of septate whorl preserved. The shell material at some places is eroded, but the internal cast is fairly well preserved.
Even in the present state of preservation the specimen clearly shows that the shell must have been fairly evolute, umbilicus being probably over 40 of the total diameter of the shell. The cross section of the whorl is somewhat squarish or slightly trapezoid with B/H almost one or slightly more than one. The sides are convex though not strongly so. The venter is broad with a moderately strong rounded keel. The part of umbilical wall which is preserved is distinctly steep. The - 33 -
ornamentation is made up of strong tubercles and ribs of which only three are preserved; they are entire simple, concave
and slightly prorsiradiate. They bear on each side four
tubercles, an umbilical, a lateral at almost mid side, an inner
ventrolateral and an outer ventrolateral, the last being the
strongest, clavate and almost parallel to the plane of coiling.
The inner ventrolateral and lateral tubercles are conical with
circular base, the lateral one being the smaller of the two.
The umbilical tubercle is conical but placed on a bulloid base
and is slightly stronger than the lateral tubercles. Judging
from what is preserved It seems probable that the inner ventro
lateral tubercle was strongly developed in the middle growth
stages, with a tendency to become smaller at later stages.
The suture is Mortoniceras type with a massive rectangular
bifid 1st lateral saddle and a comparatively narrower bifid 1st
lateral lobe. The second lateral saddle is asymmetrically bifid
and much slender and snfiller than the first lateral saddle. The
second lateral lobe is not clearIj^ visible but almost reaches
the umbilical seam.
Remarks ; The present material is assigned to Mortoniceras
(Pumovarites) as it shows all essential morphological
characters of the genus and subgenus. The specific identificati(
seems to be rather difficult because of the fragmentary nature
and inadequate number of specimens. - 34 -
The present species Is coaparable to Mortoniceras
(Purnovarites) subquadraturn Spath (Spath, 1931, vide supra)
from Upper most Albian (dlspar-perlnflatum subzone) of England
and also collected by us from Gypseous clays from Lower Utatur
group near Utatur, but shows better development of outer ventro
lateral tubercles, and persistence of tubercles to later stages
of growth. The last feature makes this species comparable to
M. (p.) quadratum Spath (Spath, 1931, p. 432, pi. XLV, fig. 3;
pi. XLVI, fig. 6; pi. XLIX, fig. 12; text fig. 151) from Upper
most Albian (dispar subzone) of England but differs in having
single ribs which are concave and prorsiradiate, and strong
clavate outer ventrolateral tubercles which rise parallel to
the plane of coiling.
It is quite possible that with more and better preserved material becoming available it may be found to be a new species
allied to M. (D.) quadraturn Spath.
Occurrence : Whitish clays of Mortoniceras inflatum zone near
Utatur.
Genus : Prohysteroceras Spath, 1921
Subgenus : Goodhallites. Spath, 1932
ProhyBteroceras (Goodhallites) stoliczkai gp. nov.
PI. IV, Fig. 2
Material : One specimen, Holotype Ut 45/70 - 35 -
Dimensions : Breadth of whorl section : 56 mm
Height of whorl section : 73 mm
B / E = 0.76
Description : The present specimen is a fragment showing parts of the inner and outer whorls. Shell is compressed and evolute with a compressed trapezoid whorl section, moderately deep umbilicus and rounded umbilical shoulder. The outer whorl shows a strengthening of ornamentation which consists of a strong mid ventral keel and broad low, rounded ribs bearing on each side four tubercles. The ribs are sinuous and prorsiradlate, separated by wider interspaces and are both long and short, though the short ones are irregular and considerably less in number. The umbilical and lateral tubercles are feeble while the ventro-lateral tubercles are low and rounded.
Remarks : The evolute, compressed nature of the shell, a strong median keel and strenghtening of ornament on outer whorl allows it to be placed in Prohysteroceras (Goodhallites) Spath.
Prohysteroceras (Prohysteroceras) sp. indet (Stoliczka,
1865, pi. XXX, fig. 5) is a closely comparable form but can be distinguished by the tendency of the present species to show strengthening of ornament on the outer whorls and also a much less number of ribs on the outer whorl.
The present species is very much similar to Prohysteroceras
(Goodhallites) goodhalli (Sow.) var. tuberculata Spath Spath, 193 - 36 - p. 447, pi. LI, figs. 2a,b) from Upper Alblan, Varlcosum-
subzone of lilackdown, Devon, England, but differs In having much feebler developmait of tubercles on the early whorls.
Occurrence : Ferrugenous clays of Mortonlceras inflatum zone near Utatur.
Section II : Apanthoceratidae
Introduction : The family Acanthoceratidae represents the great burst of radiation among amnionoids of the Cenomanian age, and consequently represents a major part of the amnionoid fauna of Cenomanian times, all over world. This family has been subdivided (Treatise p. L410) into four subfamilies,
Mantelliceratinae, Acanthoceratinac, Metoicoceratlnae and
Klammitinae .
Major part of the present collection could be assigned
to the first two of these subfamilies i.e. Mantelliceratlnae and Acanthoceratinac. Wright (1957, p. L411) in Treatise on
Invertebrate Paleontology has diagnosed Mantelliceratlnae as
'’Involute to rather evolute, round-whorled or compressed, rarely depressed; usually with prominent ribs dominant over tubercles where these occur".
In the present collection most of the forms show dominance of tubercles over ribs in the very early stages of ontogeny; while, in later stages they show dominance of ribs over - 37 - tubercles. Also there is a very wide variation in the cross section; hence It is difficult to place them in Mantelliceratinae
Similarly Acanthooeratinae is diagnosed as showing dominance of tubercles over ribs. But in the present collection fontis assigned to Acanthoceras on the basis of other characters show dominance of ribs over tubercles, on the last whorl. Thus species of these groups in the present collection to some extent bear a mixture of characters shown by both these sub- faiailies. It is, therefore, preferred here not to make any distinction on subfamily level. This approach is not new; because recent workers, e.g., Kennedy (l97l), etc. have on the same basis preferred not to make such distinction. Therefore, in the systematic description of the Acanthoceratid species that follows they are treated without showing them grouped separately under these two subfamilies.
Stoliczka (1865) reported 11 species which could be assigned to Acanthoceratidae as it is now defined. As mentioned earlier Kossmat (1897) while studying Warth's collection revised Stoliczka's work and recognised 27 species of Acanthoceratids. He transferred Amaonites rhotomagensls of Stoliczka to .Acanthoceras newboldij^and its varieties newboldi. planicostrta. and spinosa, and also recognized,
Acanthoceras tumeri White. A. cenomanense (d'Arch.), A, tropicum (Stol.^, A. crassitesta (Stol.), A, mantelli (Sow.;,
A. laticlavium (Sharpe), A. ushas (Stol.), A. morpheus (Stol.), - 38 -
A. discoidale Kossmat and Olcostephanus rudra (Stolo). Most of these species listed above are rare in South Indian
Cretaceous deposits and are not present in our collection.
The Acanthoceratids in the present collection are represented by 39 species being distributed as Mantelliceras -
3 species; Calj^coceras - 16 species; Eucalycoceras - 4 species;
Acanthoceras - 6 species; Euoaphaloceras - 3 species,
Kanabiceras - 1 species; Romaniceras - 4 species;
Colerooniceras -Ispecies; Utaturiceras - 1 species.
Of these 39 species, 20 are reported by Stoliczka (1865), Kossmat
(1897) and Sastry e_t a]^. (1968) from these deposits of South
India; 9 species are known to occur in other regions but are now reported for the first time from the South Indian Cretaceous deposits. 10 species are new to science; while, because of poor state of preservation one species is described as indeterminate.
As metnioned earlier there are a number of species already reported from these rocks by Stoliczka and Kossmat but are absent in the present collection. Of the species present in our collection under study Aanionites coleroonensis Stoliczka has been now transfei.red to a new genus Colerooniceras. As mentioned above what was reported by Stoliczka as Am’aonites rhotoaiagensis Defrance was ti'ansferred by Kossmat to Aoanthooeras newboid^iI But present author is now reporting from these beds
Aoanthooeras rhotomagense Defrance as represented by its two - 39 -
varieties, viz, A. rhotomaprense var, sussexiense (Mantell)
and A. rhotomagense confusum (Gueranger).
In the Upper Cretaceous sequence of South India
Acanthoceratids occur throughout the Utatur group almost as
characteristic of it, but are also found occurring, though
much depleted, in the basal part of the Trlchinopoly group,
suggesting a continuity at least in some sections, e.g., in
the neighbourhood of Kolakajnattj«n, from the Upper Utatur into
the basal Trichinopoly. The junction between them is not often
very clear; the ambiguity of relations is due also to slight changes in the lithology. The Trlchinopoly group being
transgresslve overlaps the Utatur group; at most of these
places this overlap is represented by thin sand^ limestones and
shell limestones resting on comparatively more clayey Utaturs; with faster erosion of these weak Utaturs the hard cap of
Trlchinopoly sinks into the Utaturs and thus further adds to
the confusion regarding the precise horizon of some of the
species.
Though as mentioned above Acanthoceratids o6<5ur all
through the Utatur group, they are particularly abundant in
the Middle and Upper Utaturs, as is also known from the work of
Stoliczka (1865) and Kossmat (l897). The present work has,
however, shown that apart from the fair abundance of
Acanthoceratids the basal part of the Lower Utatur is
characterized by Mortoniceratids and the Delemnites, and - 40 -
Mantelllceras characterises the rest of It. Similarly the
Middle Utatur is characterised in its lower portion by
Acanthoceras rhotomagense. the upper part shovi'ing the abundance
of Calycoceras choffati. Thib distribution of these more
conspicuous species leads the present author to suggest
division of the Lower and Middle Utat^rs, each into two, and / thus on the whole divide the Utaturs into five zones instead
of tliree as at present recognized. This subject is discussed
in detailed manner in Chapter IV.
Family : Acanthoceratidae Hyatt, 19C0
Genus : Mantelllceras Hyatt, 1903
The genus Mantelllceras Hyatt is represented in the present
collection by only a few species. They come from the Lower
Utatur group at Odium, Utatur, etc. Stoliczka (1865) and
Kossmat (1897) had reported amjnonolds now placed under this
genus from the Lower Utatur group as Ammonites mantelli Sowerby
(stoliczka 1865, p. 81, pi. XLI, figs. 2,3, pi. XLII, figs.1-3)
of which the specimens illustrated in pi. XLI,figs. 2,3; pi.XLII,
fig, 1 are assignable to Mantelllceras tuberculatum (Mantell),
while, that Illustrated in pi. XLII, fig. 3 is assignable to
Mantelllceras saxbli (Sharpe). In addition to these Kossmat
(1897) has also recorded Acanthoceras discoldale Kossmat which
again as the present author considers it, is better assigned to
Mantelllceras Hyatt. As mentioned further down (also vide
Ih ^o2c> - 41 -
Chapter IV, p. |57 ) Mantel11ceras occurs only in the upper
part of Lower Utatur group and hence makes recognition of this
division easy, though it is associated with Calycoceras species
of the newboldl group which continue into the next higher zone
commonly known as the Calycoceras newboldl zone.
Man tellie eras fauna in general, is poorly developed in
South India and with considerable efforts it has been possible
to collect only a few specimens of it. Stoliczka has reported
them to be ccmr.on around Odium, this could, however, be due to
the fact that some species in the Middle growth stages of
newboldl group are very much similar to Mantelliceras species
with which they were probably confused. They are, however,
distinguished by the presence of a siphonal row of tubercles
in the early stage of ontogeny.
The present collection of Mantelllceras is assignable to
Mantelllceras tuberculatum (Mantell), MantellIceras cf,
Mantelliceras saxbil (Sharpe) and Mantelliceras aff.
Mantelliceras mantelll (Sowerby).
Mantelliceras tuberculatum (Mantell)
PI. IV, Fig. 3
1822 Ammon 11es mante 111 var. tuberculatus Mantell : Mantell, p.H^
1856 Ammonites mantelll Sowerby : Sharpe, p. 39, pl• XVIII, figs. 6 a,b only
1865 Ammon1tes mantelll Sowerby : Stoliczka, p. 81, 42, figs. 1 a,b, 2 only - 42 -
1865 Ammonites vlclnalls Stollczka : Stolicfcka, p. 84, pi. 44, fig. 2 only
1926 Mantelliceras tuberculatum (Mantell) : Spath, p.
Mate rial : Two specimens, Plesiotype Od 6 / 70
Dimensions : Diameter of shell ; 183.0 mm (1)
Breadth of whorl section: 54.0 mm (0.29)
Height of whorl section : 66.0 mm (0.36)
Umbilical diameter : 61.0 mm (0.33)
Breadth of whorl section at i whorl : 54.0 mm (0.29)
Height of whorl section at i whorl : 55.0 mm (0.30)
B / II = 0.81, B/H at i whorl = 0.98
Remarks ; The present material is identified as Mante1 Tic eras tuberculatum (Mantell) as it shows a moderately large shell; compressed; a narrow concave venter; a fairly large not deep umbilicus; \34/rib^ or so per whorl, which are narrower than the interspaces; strongly tuberculate on earlier whorls but show»i»j a tendency to weakening on the last whorl; double umbilical tubercles.
Occurrence : Brownish clayey limestone, from Lower Utatur group
(Mante lliceras tuberculatum zone) near odium and \3tatur.
Pistribution . Outside South India this species Is known to occur widely in the Lower Cenomanian of England, France,
Germany, Austria, Madagascar, etc. - 43 - sp. Mantel lice ras |cf. Mantellicer as saxbii ( Sharpe)
PI. IV, Fig. 1
Material : Two specimens, Holotype Kn 115/72
Dimensions Diaaicter of shell ; 125.0 mm (1)
Breadth of whorl section; 44*0 mm (0.35)
Height of whorl section ; 62.0 mm (0.41)
Umbilical diameter : 38.0 mm (0.30)
Breadth of whorl section at i whorl ; 36.0 mm (0.28)
Height of whorl section at ^ whorl : 40.0 mm (0.32)
B/H = 0.84, B/H at i whorl = 0.90
Description : The shell is of moderate size, compressed. The specimen is damaged, being broken on one side*, even in this unfavourable state of preservation, ornament on one side makes its detailed description possible. The cross section is taller than wide with some-what rectangular shape. The venter is flat to very slightly arched. The ventrolateral shoulders «re rounde and so irs the umbilical shoulderj. The umbilicus is moderately large with steep walls and not very deep.
The earlier whorls show a somewhat more compressed cross section and are ornamented by strong ribs which are rounded, both long and short, numerous and broader than the interspaces.
The longer ribs originate from the umbilical bullae; on the mid sides they appear to be not so strong as at the umbilical bullae
The shorter ribs almost reach the umbilical seam. The intercal£ - 44 - short ribs are more numerous on the earlier whorls where the number is three or even more between two successive long ribs; gradually their number reduces to one on the later part of the shell. Not much of ventral ornament is visible on earlier whorls, but presumably there are inner and outer ventro lateral tubercles which on later stages are somewhat clavate.
There are umbilical tubercles at the beginning of every long ribs. The lateral tubercles or the double umbilical tubercles are totally missing. The two outer ventrolateral clavil are placed close together and have a depressed area on the mid venter.
The last whorl and part of the body chamber are ornamented with ribs similar as in earlier part but showing a tendency to become strong as on mid sides, and to lose tubercles; the interspaces grow wider and the ribs become somewhat narrower and elevated though on the venter they show a slight weakening.
The sutures are not well preserved, but whatever is seen is broadly in agreement with the Mantelliceras pattern.
Remarks : The present species resembles Mantelliceras stixbli
(Sharpe) from the Middle part of Lower Cenomanian of England in most respects; but it differs in having a larger number of ribs on the last whorl, about 40 as against 30. As our material is slightly crushed and damaged on one side it is felt that presently it be treated as only closely resembling Mantelliceras saxbil i.e. as M.j^cf M. saxbii (Sharpe). The present material - 45 -
Is similar to Ammonite s man telll Sowerby (Stollczka, 1865, p.81, pi. 42, figs. 3 a,b,c) from the Utatur group at Odium which now
should be assigned to Mantelliceras saxbll feharpe).
Thomel (1972) has studied and reclassified Mantelliceras and has placed saxbii of Sharpe in the subgenus Submante11iceras
Spfllth-which is regarded by Wright (1957, p. L41l) as a synonym of Mantelliceras. Submantellieeras Spath as defined by Thomel
(1972) is characterised by an absence of faint indications of lateral tubercles. Our species resembles some of Thomel*s figured specimens (particularly p i.2, fig. 3; pi. 7, fig, 11).
It is difficult to comment upon the division of Mantelliceras into subgenera as our material is not sufficiently abundant and as a whole the Mantelliceras fauna is poorly developed in the
Upper Creteceous rocks of South India.
Some of the recent workers e.g. Kennedy and Hancock (1971) have preferred to treat several species of Mantelliceras, e.g..
Mantelliceras hyatii Spath and Mantelliceras martimpreyi
(Coquand) sensu Pervinquiere as synonymous with Mantelliceras saxbii (Sharpe)^ have even doubted the generic position of
Utaturiceras vicinale (Stoliczka) and have preferred to treat it as an extreme variant of Mantelliceras saxbii (Sharpe).
Occurrence : Brownish clayey limestones of Mantelliceras tuberculatum zone near Kunnam. - 46 -
Distribution : Mantelliceras saxbll (Sharpe) to which our speclmenv Is “Very close is widely distributed in the Lower
Cenomanian of England, France, Madagascar, Spain, Portugal,etc.
Mantelliceras ^aff. Mantelliceras mantelli (Sowerby)
PI. V, Fig. 3
Material : One specimen, Holotype Ut 70/70
Dimensions : Diameter ol shell : 220.0 mm approx. (l)
Breadth of whorl section:80.0 mm (0.35)
Height of whorl section: 93.5 mm (0.42)
Umbilical diameter : 72.0 mm (0.32)
B/H = 0.85
Description : The shell is somewhat damaged though part of the body whorl and the inner whorls are well preserved. It is large, compressed, evolute. The body v?horl has an oval to rectangular cross section, narrower at the venter than at the umbilicus. The ornamentation consists of strong rounded ribs arising from faint umbilical bullae and crossing the venter uninterrupted. They are long and short, the short ones reaching only the mid sides; they are sinuous though not strongly so.
There are very faint indications of ventrolateral tubercles.
The middle and early growth stages are characterised by a similar ornament*^ 6nly with the difference that the ribs are somewhat feebler and the outer ventrolateral tubercles are more prominent; the number of short intercalary ribs is more being - 47 - two or three. The ribs are slightly prorsiradiate; the cross section Is rectangular with almost flat sides or a little sloping In towards the umbilicus and a faintly concave broad venter.
The sutures are like Mantelllceras.
Remarks : This specimen is provisionally identified as Sp Mantelllceras|aff. Mantelllceras mante111 (Sowerby) with which
It shows eo&e resemblance.
Occurrence : Ferruginous sandy clays of Mantelllceras tuberculatum zone at Utatur clay mines.
Distribution ; Mantelllceras mantelll (Sowerby) Is widely known from the Lower Cenomanlan of England, France, Madagascar, etc.
Genus : Calycoceras Hyatt, 1900
The genus Calycoceras forms the main bulk of fossil fauna of the Middle Utatur Group. This genus Is highly variable and has been differently diagnosed and described by various workers.
Thus,Wright (1957, p. L413) has diagnosed It as "Rather evolute, with depressed round, oval or quadrate whorl section; strong, generally straight ribs, continuous over rounded or flat but not concave venter; umbilical, ventrolateral and siphonal tubercles and in most cases mediolateral tubercles at least on early whorls; in multituberculate forms, umbilical tubercle is more prominent than lateral; tubercles may disappear with age ai - 48 - then rejuvlnate on last part of the shell” . He has shown its origin from a bituberoulate Mantelllceras but he has also pointed out that •' an unnamed group (usually assigned to
Calycoceras ) is probably derived directly from a species of
Stoliczkaia different from that which gave rise to Mantellieeras"
Matsumoto al_., (1957) have diagnosed Calycoceras as
”Whorls are typically depressed to sub-rounded, but sometimes not so inflated, having an arched venter. Ribs are elevated but relatively narrow aid consist of alternating long and short ones upto the full grown stage. In the more or less young stage median-r-ventral, outer and inner ventrolateral and umbilical tubercles are well developed. As a general tendency the outer tubercles are sooner or later weakened or nearly completely obsolete, as the shell grows on, while the ribs are prominent throughout life, crossing the external side without weakening.
However, in some oases the peripheral tubercles persist to, or rejuvinate on, the full grown, outer whorl. Even in such cases the ribs are still prominent. The suture is similar to that of
Mante11iceras" . This diagnosis has been generally accepted by
American workers (Cobban 1970-72). Thomel (l972), however, has divided Calycoceras into three subgenera, Calycoceras.
Gentoniceras and Lotzeites. Kennedy (l97l) has divided this genus into the following groups ;
(i) Calycoceras (sensu stricto) . C. naviculare (Mantell), C. boulei (Collignon), C. bruni (Fabre);- Distinctly inflated, high
Cenomanian forms. - 49 -
(ii) C. newboldi (Kossmat), C. newboldl splnosum (Kossmat),
C. orientale Matsumoto; - splnose; Middle and Upper Cenomanian forms, homeomorphic with some species of Acanthoceras.
(iii) C. gentoni (Brongniart), C, paucinodatum (Crick), C, bathyomphalum (Kossmat); - small forms with strongly tuberculate
Inner whorls and strongly ribbed non-tuberculate outer whorls; largely Middle Cenomanian.
(iv) C. choffatl (Ko8sraat\ C. coleroonensis (Stoliczka),
sinuosum Collignon; - compressed densicostate forms with tabulate venters, high Middle Cenomanian and Upper Cenomanian.
(v) C. lotzei (Wiedmann), C. aberrahs (Kossmat), C, barruei
(Pervinquiere); Cheloniceras like forms with strongly developed close-spaced spinose, umbilical and lower ventrolateral tuberclf;s, and a depressed whorl section. Known largely from nuclei; high, Middle Cenomanian and Upper Cenomanian.
There is a lot of confusion regarding identification of even the well-known species viz. Calycoceras naviculare.
The newboldi group was assigned to Calycoceras by Wright
(1957) and Matsumoto e_t (1957). Thomel (1972), however, has created a new genus Newboldlceras with Acanthoceras newboldi
Kossmat as its genotype and in his generic diagnosis he has stressed their being intermediate between Calycoceras on one hand and Acanthoceras on the other. Though, it is true to a - 50 - certain extent it is felt by the present author that similarities are more with the Acanthoceras rhotomagense on specific level, while the generic characters go better with
Calycoceras rather than Acan thoceras. It is unfortunate to see improper identification of newboldi Kossmat by Thomel (1972).
The present author thinks that most of Thomel’s specimens would be better assigned to rhotomagense Defrance, while some of
Thomel*s specimens identified as rhotomapense definitely belong to newboldi Kossmat, In such a condition, though it is felt by the present author that a new genus is needed to accomjiodate these forms it is postponed till it is possible to examine some of the English and French specimens considered as belonging to newboldi.
Calycoceraa lativentralis sp. nov.
PI. V, Figs. 1, 2
Material : Three specimens, Holotype Ut 31/70
Dimensions Diameter of shell : 92.5 mm (1)
Breadth of whorl section ;: 48.0 mm (0.51)
Height of whorl section : 36.0 mm (0.38)
Umbilical diameter : 30.0 mm (0o32)
Breadth of whorl section at i whorl : 36.0 mm (0.38)
Height of whorl section at i whorl : 24.0 mm (0.27)
b/H = 1 .3 3 B/H at 2 whorl = 1.35 - 51 -
Descrirtlon : Shell rather small, depressed with an exceptionally broad slightly arched, venter; fairly evolute with large and deep umbilicus which has steep walls. The shell is characterised by a very rapid broadening of the whorl section, which results in a very dept^slsBd-whorl section, with the sides somewhat flat.
The ventrolateral shoulder is well formed and so is umbilical one,
The early whorls are, however, compressed with whorl oHfly sectionj^slightly broader than high and a somewhat arched venter.
The early whorls are spinose and strongly ornaraented. The ernamentation consists of short and long strong ribs and spinose tubercles^ it is very difficult to say whether the ribs dominate dver tubercles or vice versa. The ribs are rounded, rectiradiate, numerous, separated by somewhat wider or equal interspaces. The long ribs runr uninterrupted between umbilical tubercles on the two sides and are Intercalated wl throne or two short ribs, which reach only the raid sides. They are bent fonvard on the venter. There are umbilical, inner and outer ventrolateral and siphonal tubercles, on each long rib. The short ribs are, however, devoid of umbilical tubercles. The umbilical tubercles are less pronounced than the inner ventro lateral tubercles which are the strongest and spinose; the outer ventrolateral tubercles are also somewhat spinose; while, the siphonal tubercles are slightly clavate. - 52 -
On the later part of the shell, however, the ornamentation
undergoes a change and the ribs become dominant over tubercles which tend to become feeble, the siphonal row is lost and the
inner and outer ventrolateral tubercles become of the same
strength. The ribs become slightly rursiradiate but remain
narrow and rounded with interspaces separating them wider. The
ribs at many places appear to bifurcate at the umbilical
tubercles; the intercalary short ribs tend to be longer and
almost reach the umbilical seam but arc still devoid of an
umbilical tubercle. The body chamber constitutes more than
half the whorl.
The sutures are like Calycoceras newboldi (Kossmat).
Remarks ; This species is similar to C. bathyomphalum (Kossmat)
in the sense that the inner whorls are spinose while outer whorls
are not so strongly ornamented with tubercles, and that the rate
of growth is very rapid and is of small size. It differs,
however, in not having strongly foi'wardly projected ribs on the
venter, and persistence of siphonal tubercles to a much larger
size of the shell.
The present species is a striking homeomorph of
Mantellioeras cantianum Spath (Sharpe 1855, pi. 18) from the
Grey Chalk near Leves in England, but can easily be distinguished
by a trituberculate venter in the early stages of growth. - 53 -
Occurrence : Brownish white gypseous clay from Mortoniceras inflatum and Mantelliceras tuberculatum zones at Utatur, Odium and near Kunnam, This species is found associated with
Mortoniceras inflatum (Sowerby).
Calycoceras pseudoporthaulti sp. nov.
PI. V, Fig. 4
Material ; One specimen, Rolotype Kn 139/72
Dimensions ; Diameter of shell : 208.0 rara (l) approx.
Breadth of whorl section: 90,0 mm (0.43)
Height of whorl section : 91.0 mm (0 .4 3 ) approx,
Umbilical diameter : 69.3 ram (0 .3 3 )
Breadth of whorl section at i whorl : 49.0 mm (0.23)
Height of whorl section at i whorl : 54.0 mm (0.25)
B/H = 0.90 b/H at i whorl = 0.90
Descrit>tion ; Shell fairly large, discoidal with somewhat compressed whorl section, and sides and venter only slightly
convex. The umbilicus moderately large not deep with steep sides
Maximum width of whorl section at the umbilical tubercles. The middle and early growth stages not very well preserved but
exhibit ornament slightly stronger than on later stages. The
ribs are weak not very broad, separated by wider inters’paces.
The pattern of ribbing is characteristically of long and short
ribs which normally intercalate, but the number of short - 54 - intercalaries not constant. Most of the short ribs reach more than 3/4th height on the sides and are devoid of umbilical tubercles. Each long rib bears umbilical, inner and outer ventrolateral and a siphonal tubercle. The tubercles are all feeble^ the umbilical tubercles being the strongest among them. The later growth stages are characterised by numerous «uki The sutural elements are shallow and the second lateral saddle slightly broader than the first lateral lobe. The second lateral lobe reaches the umbilical seam. 0 Rema rks : This species is very much similar to Calycoceras newboldl (Kossmat) from the Middle Utatur group of South India, In its early and middle growth stages. But can be distinguished by much wider interspaces separating the ribs and a closer placement of the Inner and outer ventrolateral tubercles. The close placement of these tubercles makes It comparable to C. tapaswii , and C. pseudocouloni, but can be distinguished by a larger size, the nature of ribbing, conical nature of inner and outer ventrolateral tubercles, a shallower umbilicus, slightly evolute form, and a compressed whorl section at all - 55 - stages of growth. Further it can also be distinguished from C. pseudocouloni by much narrower ribs which are separated by wider interspaces. The closer placeracnt of inner and outer ventrolateral tubercles and a compressed form makes this species comparable to C. orient ale Matsumoto (Matsumoto al^. 1957, p. 16, pi. 5, figs. 1 a,b,c; pi. 7, fig, l) from Palaeogyliliian or zone of Desmoceras (Fseudonhligella) .japonicum in Hokkaido, but can be distinguished by a much more evolute shell, much feebler ornament with bullate umbilical tubercles which appear even as thickened ribs. The bullate nature of tubercles and shallow umbilicus of this species makes it comparable to Calycoceras (Conlinoceras) gilberti Cobban and Scott (Cobban and Scott, 1972, p. 61, pi. 1, pi. 2, figs. 5-9; pi. 3, figs. 5-7, ll) from Graneros Shale (Late Cenomanian), South Eastern Colorado in IT.S.A., but can be distinguished by a peraistantly much larger number of ribs per whorl even on the later growth stages. Occurrence : Brown sandy limestone of Calycoceras choffati zone near Kunnaui. Calycoceras tapaswli sp. nov. PI. VI, Figs. 1,2 Material : Four specimens. Holotype Kn l/l5- - 56 - Dimensions; Diameter of shell : 113.0 mm (li approx. Breadth of whorl section:56.0 mm (0.49) Height of whorl section :50.0 ram (0.44) Umbilical diameter : 36,00mm (0.3l) Breadth of whorl section at i whorl : 36.5 mm (0.32) Height of whorl section at i whorl : 32.5 ram (0.28) B/H =1.1 b/H at i whorl =1.1 Description : The shell is rather small, moderately evolute. The whorl section is squarish with width only slightly more than the height. Sides are flat; venter broad, flat between the outer ventrolateral tubercles, but between the inner ventro lateral tubercles it is broadly arched. The umbilicus is moderately large and fairly deep with broadly rounded umbilical shoulder and a steep umbilical wall. The early growth stages show ornament somewhat feebler than at later stages. It consists of ribs and tubercles of which ribs are more conspicuous. The ribs are almost recti- radiate rounded and separated by interspaces equal or wider than the ribs. The ribs are both long and short, one or two short ribs intercalating between two successive long ribs. 01 the long ribs some are stronger than the rest and also bear stronger tubercles.^ Long ribs bear umbilical tubercles which are often spinose and raised on the stouter of the ribs and feeble or almost undescemable on others. The inner and outer - 57 - ventrolateral tubercles are almost of equal strength and a siphonal tubercle. The ventrolateral tubercles are conical and though placed on slightly olavate base, are always within the width of the ribs. From the middle growth stages of the shell the cross section becomes slightly more tumid. The ribs become somewhat sinuous and project forward on the venter; this feature characterises the middle and early late growth stages. The siphonal tubercles disappear in the later part of middle growth stage of the shell. The ventrolateral tubercles come closer and remain so in the later growth stages with the outer ventro lateral tubercles becoming weaker on some of the intercalarj^ short ribs. On the later growth stages the ribs still remain long and short, but loose the sinuosity, and straighten out to a recti- radiate course. The forward bend on the venter is also lost. The height slightly increases as compared to the breadth of the whorl. The umbilicus also increases in proportion. The umbilical tubercles show a tendency to become bullate. The ribs are separated by much wider interspaces than before. The sutures, in general, are like Calycoceras newboldi (Kossmat) with a slightly broader first lateral lobe. The second lateral lobe is shallow and almost reaches the umbilical seam. - 58 - Remarks : The present species Is very much similar to Calycoceras newboldi (Kossmat) from Middle Utatur group of South India but can be distinguished by sinuous ribs on the middle growth stages of the shell a closer placement of the two ventrolateral tubercles and a relatively early loss of siphonal tubercle. It is felt that the present species is a quear mixture of characters of members of Calycoceras newboldi group, viz. newboldi and spinosum and also C. choffati (Kossmat) with which it is associated here. The slight unequal development of inner ventrolateral tubercles and close placement of inner and outer ventrolateral tubercles make this species comparable to Calycoceras orientale Matsumoto and C. asiaticum (Jimbo) from Paleogyllakian in Hokkaido, Japan, but can be distinguished from the former by a more depressed cross section and slower rate of growth of the shell, and from the latter by not having any bullate outer ventrolateral .tubercles. Occurrence : Brown concretl6nary sandy limestone from the Acanthoc eras rhotomagense zone and Calycoceras choffati zone near Kunnam and Odium. This species is named after Dr. P. M. Tapaswi who has worked on Cretaceous Bivalves of South India. - 59 - Calycoceras pseudocouloni sp. nov. PI. VI, Figs. 3, 4 Material : One specimen, Holotype l/l7 Dimensions : Diameter of shell : 102.5 mm (l) Breadth of whorl section: 48.0 mm (0.46) Height of whorl section : 51.0 mm (0,49) Umbilical diameter : 31.5 mm (0,30) Breadth of whorl section at i whorl : 31.0 mm (0.30) Height of whorl section at i whorl : 31,0 mm (0.30) B/H =0.78 B/H at i whorl = 1.00 Description ; Shell moderately evolute growing rapidly with polygonal cross-section, the height being slightly greater than the breadth. The venter is broadly arched tending to become flat, between the outer ventrolateral tubercles. The sides are convex though not strongly so, the maximum breadth of cross section is near the umbilical shoulder. The umbilical wall is almost verticle . The ornamentation consists of broad, low but well defined ribs with a §teeper posterior slope. There are 17 ribs on the last half whorl. Over most of the part of the shell ribs are rectiradiate but become prorsiradiate on the last stage. On the middle growth stages of the shell, the ribs are strong and originate as twins from well developed umbilical tubercles. On the last half whorl they are alternately short and long, the - 60 - longer ones starting on slightly developed umbilical bullae. In general the tubercles are subordinate to the ribs in their development. They are placed at umbilical shoulder, ventro lateral shoulder and the mid ventral positions. The siphonai tubercles disapupear early in the mid growth stage of the / shell, but reappear on the body whorl as slightly developed clavi. The umbilical tubercles are bullate and exhibit a tendency to become feeble with development of the shell. There are two closely placed rows of ventrolateral clavate tubercles; the inner ones are less developed than the outer ones, on the septate portion of the shell, but on the body chamber they tend to become more pronounced. The sutures are not well preserved as the specimens is weathered but Acanthoceras like character is discernable. Remarks : This species is comparable with C, orientale Matsumoto (Matsumoto e_t 1957, p. 16, pi. 5, figs. 1, a,b,c, pi. 7, fig, l) from Paleogylikian (or the zone of Desmoceras (Pseudo- ahllgella) .japonicum ) in Hokkaido, but differs in a much wider umbilicous at much smaller diameter of the shell and having a much smaller shell of the adult. The present species is much like planicostata (Kossmat) in having feeble ornamentation but differs in having upper and lower ventrolateral clavi closely placed and broad ribs with narrower interspaces. - 61 - The present species is similar to Acanthoceras rhotomagense var. clayatum Kennedy & Hancock (Kennedy & Hancock 1971, p. 479, pi. 196, fig, 2) from Craie de Rouen, France, but differs in many respects viz. alternating long and short ribs persisting on the whorl shell, dominance of ribs over tubercles at all stages of growth, a much more compressed cross section, etc. This species is homoeomorphic to Mantelliceras couloni (d'Orbigny) (Collignon, 1937, p. 32, pi. 11, figs.l, la, lb) from Cenomanian of Madagascar but is distinguished by the presence of siphonal clavate tubercles and persistence of ventrolateral tubercles. Occurrenc e ; Brownish clayey limestone of Acanthoceras rhotomagense zone near Odium. Calycoceras sastrii sp. nov. PI. VII, Figs. 3,4 Material ; Several specimens, Holotype Kn 11 Dimensions; Diameter of shell 230.0 mm (1) Breadth of whorl section 110.0 mm (0.47) Height of whorl section 100.0 mm (0.43) Umbilical diameter 85.0 mm (0.37) Breadth of ^^horl section at i whorl 85.0 mm (0.37) Height of whorl section at i whorl 65.0 mm (0.28) b/H =1.1 B/n at -h whorl = 1.38 - 62 - Description : Shell is moderately large, evolute with polygonal cross section. The intercostal section is rounded approaching a circular shape. The venter is arched and broad. The umbilicus is fairly deep with steep walls. The ornamentation consists of strong ribs and tubercles. The tubercles are a little stronger than the ribs on the earlier whorls but in general the ribs dominate and at later stage of growth the tubercles tend to weaken and some even tend to disappear. The ribs number about 30 on the body whorl; they are alternately short and long. The longer ribs arise on the umbilical wall and are weak and rursiradiate till they reach the umbilical tubercle, after which thsy take almost straight course to slightly rursiradiatej[ cross the venter uninterrupted, without any change in strength. The anterior slope of the ribs is usually gentler than the posterior one. The shorter ribs arise very near the umbilical edge and are somewhat weaker than the longer ribs on the sides. But on the venter they are equally strong. Characteristically in the middle growth stages, t e two short ribs intercalate between successive long ribs, but on the body whorl it is only one rib except at one place where the short rib is missing. Each long rib has an umbilical, a veiy faint mediolateral, closely placed inner and and outer ventrolateral tubercles on each side^ fi siphonal tubercle it well seen upto the middle growth stager after which th The body chamber occupies almost half of the last whorl. The shell grows rapidly so as to produce a deep umbilicus. In the later stages the shell grows more in height than in width; cross section is much depressed at half whorl but almost equi- dimensional on the last part of the body chamber. Sutures are simple with massive bifid first lateral saddle and a bifid narrower lobe. The^second lateral saddle almost readies the umbilical seam. The second lateral lobe is placed on the umbilical wall. Remarks The general pattern of ornarcen tation allies this species to the Calycoceras newboldi group of species. It differs from C. spiaosum (Eossmat, 1897, p. 7, pi. 2, figs. 2 a,b,c, 3 a,b; pi. 3, figs. 1 a,b) from Middle Utatur group in having a polygonal rather than a subquadrate cross section in later stages - 64 - of shell growth in having a faint mediolateral tubercle, in the mid-growth stages the interspaces as broad as the ribs, as against wider interspaces in C. spinosuci (Kossraat); its ribs rectiradiate on the sides as against arcuate in C, spinosum (Kossmat) and the umbilical proportion after 200 mm diameter of the shell as 37 % as against 30 % in C. spinosum (Kossmat). The present species can be distinguished from C. orientale Matsumoto (Matsumoto £t 1957, p. 16, pi. 5, figs 1 a,b,c; pi. 7, fig. l) from the Paleogylikian (or zone of Desmoceras (Pseudouhligella) .japonicum ) in Hokkaido by a much more depressed cross section and a much more evolute shell. On the same points the present species is distinguished from its nearest ally C. tune^tuin-' (Pervinquiere) from the Cenomanian of Tunisia. Occurrence : Clayey limestones of Acan thoceras rhotomagense and Calycoceras choffati zones near Kunnam and Odium. This species is natied after Dr, M. V. A. Sastry, Director of Palaeontology Division, Geological Survey of India. Calycoceras mamgaini sp. nov. PI. VII, figs. 1, 2 Material : Four specimens; Holotype Kn 188/72 Dimensions; Diameter of shell : 114.0 mm (l) approx. Breadth of whorl section: 55.0 mm (0.48) - 65 - Height of whorl section ; 47.0 ram (0.4l) Umbilical diameter : 36,3 mm (0.3l) Breadth of whorl section at i whorl : 42.0 mm (0.36) Height of whorl section at i whorl : 38.0 mm (0.33) B/H = 1.17, B/H at i whorl = 1.10 Description : Shell evolute, moderately tumid with polygonal whorl section broadest at the umbilical tubercles and slightly less depressed in early stages. The ventrolateral and umbilical shoulders well formed, rounded. Venter is slightly arched, though at later stages due to increasing praTiinence of outer ventrolateral tubercles it appears concave; the intercostal section is roundish and narrower at venter. The umbilical wall is steep and almost vertical. The ornamentation consists of strong ribs and tubercles of which the former dominate over the latter. The early growth stages are characterised by a stronger ornament; ribs are sharp with pointed umbilical, inner and outer ventrolateral and siphonal tubercles, the umbilical tubercles being the strongest of all; the ribs originate at the umbilical tubercles, and often show bifurcation at them. The umbilical tubercles are placed on bullate base, while the outer ventrolateral tubercles are ciavate. In the later stages of growth of the shell the ribs become somewhat flattened though they still remain strong and the interspaces are as broad as the ribs or may be even - 66 - slightly broader. The ribs are cliaract eristic ally alternately long and short with every long rib of one side ending on the other as a short rib. The shorter ends of the ribs reach upto half of the sides and thus the ornamentation is not symmetrical on the two sides. The siphonal tubercles tend to weaken and disappear on the later part of the shell. The ribs are almost rectiradiate on the sides but are bent anteriorly on the venter. The sides tend to become somewhat more convex in later stages of growth where they are almost flat. The suture is Calycoce ras type. Remarks : Shorter ribs of 6ne side being longer on the other, makes this species comparable to Mantellice ras japonicum Matsumoto and Muramoto (Matsumoto e_t a^. 1969, p. 253, pi. 25, figs. 1-2; pi. 26, figsl 1-3; pi. 27, figs. 1-2, text figs. 1-2) from lower part of Unit Ilb, Mikasa Formation at IkshumbetB main valley, Japan. But it can easily be distinguished by having a siphonal row of tubercles which places it in Calycoceras, Some of the specimens of Calycoceras naviculare (Mantell) from North America have been reported by Cobban,(l97l) to show a pattern of ribbing like that of the present species, which however, is restricted to only to certain diameters of the middle growth stage of the shell and changes later on. This species, however, has still greater resemblance to C. planicostata (Kossmat) (Kossmat 1897, p. 9, pi. 2, figs.l a,b,< Stoliczka 1865, p. 68, pi. 35, figs. 1 a, b) from Middle Utatur - 67 - group, though can be distinguished from it also by stronger ornament persistant on later stages also and with long ribi being short on the other side. The similarity in shape of the cross section of the present species and C, planicostata (Kossmat) indicates that they are closely allied and belong to the same group of species i.e. C. newboldi group. Specimen No. Od 59 in our collection is a fragment of the body chamber of an adult which shows ribbing pattern similar to that of this species as described above, the only difference being that its ribs are not so broad as in the Holotype. Specimen No. Od 89 and No. Od 43, also show similar pattern of ribbing though they show crowding of ribs on the inner whorl; this latter feature is a character of C. choffati (Kossmat), (See PI. VIII, Figs. 3 & 4), but crowding of ribs is less important than their characteristic short and long nature and hence these are placed in the present species. Occurrence : Yellowish sandy limestone of -Acanthoceras rhotomagen se and Calycoceras choffati zones near Kunnam and Odium. This g) ecies is named after Mr. V. D. Mamgain, Geologist of the Geological Survey of India (Palaeontology Division). - 68 - Calycoceras sp. indet PI. VIII, Figs. 1, 2 Material Two specimens, Holotype Kn l/l8 Dimensions Diameter of shell : 102.0 mm (l) Breadth of whorl section: 52.0 mm (0.50) Height of whrol section : 49.0 mm (0.48) Umbilical diameter : 27.0 mm (0,26) Breadth of whorl section at i whorl 34.0 mm (0.33) Height of whorl section at ^ whorl 31.0 mm (0.30) b/H = 1.05 B/H at i whorl = 1.09 Description : Shell not large, moderately involute; umbilicus small, deep with steep walls) Venter not strongly arched*, cross section rounded polygonal', the earlier whorls slightly wider than high with somewhat flat sides, later tending to be convex. The ornamentation consists of strong round ribs, numerous, flexuous, long and short, broadening and slightly bejding forward on venter, and separated by almost equal inter spaces. The tubercles subordinate to ribs with tendency for tubercles to weaken on the later growth stages conspicuous. The ribs are alternately long and short with the shorter ribs reaching slightly more than i side. Ev eiry long rib bears umbilical, inner and outer ventrolateral and siphonal tubercles of which the inner ventrolateral and umbilical ones are conical, tending to be spinose. The outer ventrolateral and siphonal - 69 - tubercles are clavate, the former being slightly raised than the latter. The siphonal tubercles are first to weaken and almost irtYter disappear beyond diameters of 65 mm. TheJ[ventrolateral tubercles are almost subequal to the outer on the earlier whorls but at later stages tend to become weaker. The umbilical tubercles tend to become bullate as the shell grows. The sutures are similar to Calycoceras newboldi (Kossmat). Remarks : The present species is comparable to C. planicostata (Kossmat) (Kossmat, 1897, p. 9, pi. 2, figs. 1 a,b,c) from Middle Utatur group in Trichinopoly District, India, but differs in having more squarish cross section, somewhat flatter, and stronger ribs, atvd stronger umbilical tubercles and an early disappearance of siphonal tubercles. This species combines characters of C, newboldi group and can best be placed in between C. planicostata (Kossmat) and C. spinostcn (Kossmat) being much less inflated than C. splnosum (Kossmat) and having much stronger ornament than C. planicostata (Kossmat). More material may help knowing its nearness to one or the other of these species. Occurrence : Brown sandy limestone of Acanthooeras rhotomagense zone near Kunnam and Odium. - 70 - Calycoceras navlculare (Mantell) PI. IX, Figs. 1, 4 1822 Ammonites navlcularls Mantell ; Mantell, p. 198, pi. 22, fig. 5 1865 -Amnionites navlcularls Mantell : Stoliczka, p. 73, pi. 39, figs. 2 a,b, 3, 4 1893 Acanthoc eras navlculare (Mantell); Sacco, p. 18, pi. 2, fig. 1 1897 Acanthoceras navlculare (Mantell): Kossmat, p. 11 1898 Acanthoceras navlculare (Mantell): Choffat, p. 72, pi. 4, figSo 6 a,b; pi. 6, figs. 1, 2a, b. 1900 Calycoceras (Ammonites) naylculares (Sharpe): Hyatt, p.589 1912 Fagesia naviculares (Mantell): De Grossouvre, p. 28, pi. 3, figs. 1 a,b,text fig, 1919 Ammonite s n avi cularis Mantell : Crick, p. 154, pi. 4. 1926 Metacalycoceras navlculare (Mantell) : Spath, p. 83 1926 Metacalycoceras grossouvrei Spath : Spath, p. 431 1931 Acanthoceras borgesi Douville : Douville*^, p. 32, pi. 2, figs. 3a,b, 4, text fig. 2 1931 Metacalycooeras borgesi (Douville^) : Spath, p. 316. 1935 Acanthoceras (Calycoceras) navlculare (Mantell) : Karenberg, p. 129, text fig. 1 1937 Calycoceras (Metacalycoceras) navlculare (Mantell) : Collignon, p. 44-49. 1957 Calycoceras navlculare (Mantell): Matsumoto, Saito & Fukada, p. 9, 10. 1965 Calycoceras grossouvrei(Spath): Collignon, p. 172, pi. B, flffs. 2a. b. - 71 - 1968 Calycoceras navlculare (Mantell) : Sastry, Rao & Mamgain, pi. 1, figs. 5, 6 1971 Calyc oceras navlculare (Mantell) ; Cobban,p. 13, pi. 1, figs. 1-3; PI. 10, figs. 1-8; pi. 11, figs. 1-5; pi. 12, figs. 1-2; pi. 13, figs. 1-5; pi. 14, figs. 1-3; pi. 15, figs. 1 & 2; pi. 16, figs. 1,2; pi. 17, text figs. 12-14. 1972 Calycoceras navlculare (Mantell) ;Cobban & Scott, p. 60, pi. 21, figs. 1, 3, 4 Material : Several specimens, Plesiotype Kn 4 Dimensions; Diameter of shell : 114.5 mm (l) Breadth of whorl section: 63.0 mm (0.55^' Height of whorl section: 52.0 mm (0.45) Umbilical diameter : 33.0 mm (0.28) Breadth of whorl section at i whorl : 43.5 mm (0.37) Height of whorl section at i whorl : 48.0 mm (0.33) B/H =1.3 B/H at i whorl =1.1 Remarks : Large, broad ventered shell with inflated cross section, maximum tumlditj’’ at umbilical tubercles; 40 or more short and long prorsiradiate ribs with similarly broad Inter spaces; tubercles, except those at umbilicus tending to disappear, siphonal» followed by othenand suture with shallow elements help in placing present specimens under this well known Cenomanian species. This species has an interesting history. As the original description of the type specimen was inadequate almost a centurj' - 72 - later Crick (1919, p. 154-155) reflgured and described it. Sharpe (1856, p. 39, pi, 18, figs. 1-3, 5,8) had Illustrated specimens which were assigned by him to Ammonites naviculares. This led to a lot of confusion as Hyatt creating the genus Calycoceras designated Sharpe's Ammonites naviculares as its genotype. Spath (1921, p. 315) remarked that Mantell's type speciaeni was of no use as it was too worne and scraped to show any tubercles, and selected the specimen illustrated by Sharpe in pi. 18, figs. 1, 8, as the Lectotype of Ammonites naviculares. This specimen has two umbilical tubercles. A few years later Spath (l926, p. 83) bel:^ed that the specimen he had selected as Lectotype was in fact Mantelliceras and referred it to a new species Cantianum. aid opined that Calycoceras and Mantelliceras were synonyms. The problem of Calycoceras andj^species iJavlculare was reviewed again in 1937 by Spath and Collignon. Spath concluded that Calycoceras and Metacalycoceras were synonyms. But Collignon regarded Metacalycoceras as subgenus of Calycoceras and Mantell's Ammonites navicularis was assigned to this subgenus. Wright and Wright (1951, p. 25) regarded Metacalycoceras and Calycoceras as synonyms. They pointed out that Hyatt's designation of Calycoceras (Ammonites) nayiculare Sharpe sp, was incorrect and according to ICZN the type of Calycoceras is C. nayiculare (Mantell) and noted that C. navicul are was ” a definite and distinct late form of the genus ". - 73 - Occurrence : From brownish sandy limestones from Mammites conclliatum zone near Kunnam, Odium and Munglepaudy. Distribution : This species has a very wide geographic distri bution being recorded from the Upper Cenomanlan of England, France, Portugal, Angola, Algeria, Spain, Tunisia, Madagascar, Japan and U.S.A. Calycoceras choffati (Kossmat) PI. VIII , Figs. 3, 4 1898 Acanthoceras choffati Kospsnat : Kossmat, p. 12, pi. 14, fig. 1 1907 Acanthoceras choffati Kossmat : Crick, p. 205, pi. 12, figs. 3, a, b 1935 Acanthoceras choffati Kossmat : Diener, p. 159 1937 Ac ant hoc eras choffati Kossmat : Basse, p. 177, pi.11,fig.5 1937 Calycoceras (Eucalycoceras) choffati (Kossmat) : Colllgnon, p.17, pi.4, figs. 1, la 1969 Calycoceras aff. choffati (Kossmat) : Kennedy, p, 75, p i.38 figs. 5 a,b; pi. 39, figs. la-c, 3a-c Haterlal : Several specimen, Pleslotype Kn 10a Dimensions; Diameter of shell 92.5 ram (l) Breadth of whorl section 35.0 mm (0.38) Height of whorl section 44.0 mm (0.47) Umbilical diameter 23.0 mm (0.24) Breadth of whorl section at i whorl 25.0 mm (0.27) Height of whorl section at i whorl : 24,0 mm (0.25) b/H = 0.79, B/H at ^ whorl = 1.0 Rem arks : Small somewhat involute shell; compressed rectangular ft cross section with flat narrow venter* trituberculate, numerous crowded prorsiradiate ribs short and long, separated by narrower interspaces; weak tubercles tending, except bullate umbilical ones, to disappear after middle growth stages, and newboldl like suture, place these specimens under the present name, rather than under C. planicostata• itacause the latter has spinose and stronger ornament, almost rectiradiate ribs less Involute shellj^ trapezoidal cross section. Some of the specimens in the present collection are slightly thicker and have ornamentation between that of C. planicostata (Kossmat) and C. choffati (Kossmat). But on the whole they can be placed under £. choffati (Xossmat). Thoiuel (1972) has put £. choffati into a new subgenus Gentoniceras. It seems that this inclusion is incoirect as there is no resemblance between C. gentoni and C. choffati. Moreover, the specimen he has figured ag £. choffati is nearer to C. planicostata, which he has included in his Newboldiceras. He considers C. choffati and C. planicostata close allies. The typical character of a tabulate venter is not at all seen in his specimens, though crowding of ribs to a certain extent is seen. Ke has also remarked that C. choffati Is a form lying - 75 - / iHii between Eucalycoceras and Calycoceras. Colllgnon had put it in subgenus Eucalycoc eras, while, Matsuraoto (1942) had put it in Eucalycoceras. Occurrence : §andy limestones of Acanthoceras rhotomagense and Calycoceras choffati zones near Kunnam, Odium, Munglepaudy, etc. Pistribution : The species occurs in Cenomanian of England, Chains subalpines raeridionales, Madagascar, Zululand and Natal, Calycoceras planicostata (Kossmat) PI. IX, Figs. 2, 3 1865 Ammonites rhotomagensis Defrance : Stoliczka, p. 68, Subcompressed variety, P I.35,figs.la-b 1897 Acanthoceras newboldi var. planicostata Kossniat ; Kossmat, p. 9, pi. 2, figs.l a,b,c 1971 Calycoceras newboldi planicostata (Kossmat) : Kennedy, p.76, pi. 41, figs. 1 a,b; 2 a,b e 1972 Newboldiceras (Newboldiceras) planjjcos ta (Kossmat) : Thomel p. 113, pi. 42, figs. 5-7 1972 Calycoceras (Gentoniceras) choffati (Kossmat) : Thomel, p.70, pi. 22, figs. 1-3; pi. 23, figs.3-5 Material ; Several specimens, Plesiotype Od 31 Dimensions; Diameter of shell : 91.0 ni:; (l) Breadth of whorl section: 39.0 mra (0.42) Height of whorl section : 40.0 mm (0.43) Umbilical diameter ; 26.0 mm (0.28) B/H = 0.97 - 76 - Remarks : This species Is identifiable by its compressed Steiitnf) trapezoidalj^tending after middle growth stages to be taller than broad and more involute; ribs arcuate, numerous, long ones separated by two to four short Interoalaries; interspaces as broad as the ribs; umbilical tubercles spinose, tending to be bullate; inner ventrolaterals and siphonals clavate; ornament in general tending to weaken. The present author agrees with Matsumoto (1957) in raising, this variety of Kossmat to the status of a species. As pointed out by him it differs from C. newboldi (Kossmat) or C. spinosum (Kossmat) on some important points, such as tendency to involution, whorl becoming taller than broad, interspaces persisting to be only as broad as the ribs, and venter remaining flat throughout. Occurrence : Clayey limestones of Mantelliceras tuberculatum. Acanthoceras rhotomagense and Calycoceras choffatl zones near Cdium, Kunnam, Munglepaudy, etc. Pis trlbution : This species has a wide geographic distribution during the Middle and Upper Cenomanian period being found in Madagascar, East Africa, Tunisia, Europe, etc. Calycoceras spinosum (Kossmat) PI. X, Figs. 2, 3 1865 Ammonites rhotomagensis Defrance; Stoliczka, p. 68, pi. 35, fig. 2, pi. 36, fig. Ipfjt/. - 77 - 1898 Acanthoceras newboldi var, splnosa Kossinat : Kossmat, p.l, pi. 2, figs. 2, a-c; 3 a,b, pi. 3, figs. 1 a,b. 1937 Calycoceras (Eucalycoceras) nevyboldl var. splnosa (Kossmat) Collignon, p. 39 1952 Calycoceras newboldi var. splnosa (Kossmat) : Wright & Wright, p. 26 1957 Calycoceras spinosum (Kossmat) : Matsumotoal., Po 14 1972 Acanthoceras (Acanthoceras) cf. rhotomagense (Brongniart) (Form 2) : Thomel p. 133, p i.58, figs. 1-3 Material ; Several specimens, Plesiotype Kn 17 Dimensions : Diameter of shell ; 185.0 mm (l) Breadth of whorl section : 95.5 mm (0.5l) Height of whorl section : 78,5 mm (o,42) Umbilical diameter ; 64.0 mm (0.34) Breadth of whorl section at i whorl : 74.0 mm (0.40) Height of whorl section at i whorl : 41.0 mm (0.27) B/H =1.2 B/H at i whorl =1.4 Remarks : Briefly this species is characterised by rapidly increasing whorl, evolute in later stages; whorl section polygonal,broader than high, broadest at umbilical tubercles, becoming almost equidimensional in late stage; ribs short and long, narrower than interspaces,some times bifurcating at umbilical tubercles and tending to be sharp; tubercles strong and spinose tending to slight weakening; newboldi like suture - 78 - but with second lateral saddle slender and first lateral lobe deeper. Matsumoto £l. (1957, p. 13) describe It as an involute shell; but present specimens appear to be moderately evolute at least in later stages. Occurrence : Common in the Acanthoceras rhotomagcnse and Calycoceras choffati zones but also found in Mortoniceras inflatum, Mantelliceras tuberculatum and Mammites conciliatum zones near TItatur, Odium, Kunnam and Munglepaudy. Distribution :This species is widely distributed in the Middle and Upper Cenomanian rocks recorded from Madagascar, East Africa, Europe, Japan, etc. Calycoceras newboldi (Kossmat) PI. XI, Figs. 1, 2 1865 i^monites rhotomagensis Defrance : Stoliozka, p. 66, p i.34, figs. 3,4; pi. 35, fig. 1; pi. 36, fig.l; pi. 37, figs. 1,2 1897 Acan thocer as newboldi Kossmat : Kossmat, p. Ill, pi. 12, figs. 2a,b, 3 a,-c; pi. 13, figs.2 a,b,o 3 a, b 1906 Apanthoceras newboldi Kossmat : Boule, Lemoiuet and Thevinin, p. 28, pi. 7, figs. 4 a,b 1907 Acanthoc eras newboldi Kosaaat ; Pervinquire, p. 264, pi. 13, figs.l a, b only 1907 Acanthoceras newboldi Kossmat : Crick, p. 177 1920 Acanthoceras newboldi Kossmat : Chudeau, p. 679 1925 Acanthoce las n ewboldi Kossmat : Diener, p. 163 - 79 - 1928 Acanthoceras newboldi Kossmat : Basse, p. 137, pi. 8, fig. 3 only 1937 Calycoceras (Eucalycoceras) newboldi (Kossmat) : Collignon, p. 14 1951 Calycoce ras newboldi (Kossniat) : Wright & Wright, p. 1957 Calycoceras newboldi (Kossmat) : Matsumoto, Sai.to Fukada, p. 9 1959 Calycoceras newboldi (Kossmat) Hancock, p. 250 1962 Calycoceras newboldi (Kossmat) Avnimeleoh et Shoresh, p. 533 1964 Calycoc eras newboldi (Kossmat) Collignon, p. 120, pi.362, fig. 1585 1965 Calycoceras newboldi (Kossmat) : Collignon, p. 27 1971 Calycoceras newboldi var. newboldi (Kossmat) : Kennedy, p. 75, pi. 38, figs,5 a,b; pi.39, figs. 1 a-c; 3a-c 1972 Newboldiceras (Newboldlceras) newboldi (Kossmat) ; Thomel, p. 106, pi. 34, figs. 1-3 (non ?); pi. 38, figs. 1,2; pi. 39, figs. 1-3; pi. 40, figs. 1-3; pi. 41, pi. 42, figs. 3-4 1972 Acanthoc eras (Acanthoceras) cf. rhotomagense (Brongniart) (Form l) ; Thomel p. 133, pi. 58, figs. 4-6. Material : Several specimens, Plesiotype Od 260/70 Dimensions; Biameter of shell : 132,5 (l) Breadth of whorl section: 66.0 (0,49) Height of whorl section : 60.0 (0,45) Umbilical diameter : 40.0 (O.SO) - 80 - Breadth of whorl section at i whorl : 44.00 mm (0,33) Height of whorl section at i whorl : 38.00 mm (0.28) d/H =1.1 B/H at i whorl = 1.16 Remarks : Cross section polygonal; venter and sides weakly convex; broadest at splnose umbilical tubercles; varying number of short ribs intercalated between long rectiradiate ribs; bifut- cAling at umbilical tubercles; both ventrolateral and siphonai tubercles clavate, weakening in middle stages of shell growth and reviving at later stages; suture with 1st lateral saddle rectangular, massive, bifid as deep as the siphonai lobe and broader than 1st lateral lobe help in assigning our specimens to this widely occuiTing species. Occurrence : From clays, clayey limestones, sandstones of Mortoniceras inflatum, Mantelliceras tuberculatum. Acanthoceras rhotomagense, Calycoceras choffati and Mammites conciliatum zones near Kunnam, Odium, Utatur, Garudamangalam, Munglepaudy, etc. Distribution : This species is very widely distributed in Cenomanian period and has been reported from Lower Cenomanian of Madagascar and Middle and Upper Cenomanian of East Africa, Tunisia, Israel, England, France, Japan, etc. Calycoceras gentoni (Brongniart) PI. X, Fig.l; Pl.XIII, Fig.2 1822 Ammonites gentoni Defrance : Brongniart, p. 83, 392, pl.6, figs. 6 A, B - 81 - 1827 Amirionltes navlcularis Mantell : Sowerby, p. 555 1863 Ammonites gentonl Brongniart : Pictet, p. 33, pi. 6 1863 Ammonites gentoni Brongniart; Pictet & Camplche, p. 315 1882 Amaonltes gentoniJ.Brongiilatt : Seguanza, p. 110 1900 Ammonites gentoni Brongniart: Hyatt, p. 589 1907 Ammonites gentoni Defrance ; Pervinqui'ere, p. 281 1937 Acanthoceras cf. gentoni (Defrance in Brongniart) : Basse, p. 178 1937 Caly6oceraB'=^(Eucalycoceras) gentoni (Defrance in Brongniart) Collignon, p. 48 1951 Calycoceras gentoni (Brongniart ex Defrance) ; Wright & Wright, p. 25 1963 Calycoceras gentoni (Brongniart) ; Renz, Luterbacher & Schneider, p. 1109 1972 Calycoceras (gentoniceras) gentoni (Brongniart) : Thomel, p. 65, pi. 21, figs. 1,2,6-8, 9-10,11-13, 14-15, 16-17,18, pi. 22, figs. 4-5. Material : Several specimens, Plesiotype Od 107/70 Dimensions : Diameter of shell : 60.0 mm (l) Breadth of whorl section:35.0 mm (0.58) Height of whorl section: 32.0 ram (0.53) Umbilical diameter : 22.0 mm (0.36) B/n = 1.09 Remarks ; Most of our specimens identified as belonging to this well known European species are septate; and considering their size, this species seems to be small or moderately sized. - 82 - Characters which have helped In our identification are moderately involute shell, with cross section slightly depressed and widest at umbilical tubercles; ribs broad as interspaces long and short, rectiradiate on sides, bending forward on venter; conical tubercles, except umbilical ones, tend to disappear after middle stage of shell growth; sutures newboldi like, but siphonal lobe deeper than other elements. Inner whorls of the present species are very much similar to Calycoceras spinosum of the newboldi group but ta cot* be. distinguished by the tendency of loss of tubercles after the middle stages of shell growth. Occurrence : Arenaceous limestones of Acanthoceras rhotomagenae zone near Odium and Kunnam. Distribution : This well known species is reported to occur in the Middle Cenomanian of England, France, East Africa, etc. Calycoceras stoliczkaj Collignon PI. X, Figs. 4, 6 1937 Me tacalycoceras stollczkai Collignon : Collignon, p. 48 1957 Calycoceras cf. C. stollczkai Collignon : Matsumoto a l. p.19, pi. 6,figs.la, b 1959 Calycoceras stollczkai Collignon : Matsumcto, p. 7S, p i.21, fig. 1 1972 Calycoceras (Calycoceras) stollczkai (Collignon) : Thomel, p. 56, pi, 17, figs. 8-10; pi. 18, figs. 5-7 - 83 - Material : One specimen, Plesiotype Od 156/70 Dimensions; Diameter of shell : 61,3 mm (l Breadth of whorl section: 41.8 mm (0.64) Height of whorl section : 32.5 mm (0.53) Umbilical diameter : 22.7 mm (C.37) Breadth of whorl section at i whorl : 27.2 mm (0,44) Height of whorl section at i whorl ; 19,2 mm (0.3l) B/H =1.28 B/H at i whorl =1.4 Remarks : This species is characterised by small evolute shell’, cross section depressed polygonal, broadest at umbilical tubercles; shoulders well formed, angular even at last stage of growth; rursiradiate ribs broad as the interspaces, alternately short and long, bw*>t forward on venter; siphonal tubercles followed by ventrolaterals tend to disappear. This species has been often talten into synonymy of C. naviculare but the author feels that though with sutural pattern like C. naviculare its present placement is established as it shows a much wider umbilicus than that of C. naviculare at comparable diameters and a much angular cross section. It is also distinguished from C. paucinodatum (Crick) from Lower Chalk of England by an angular cross section and sharper ribs as broad as Interspaces. Occurrenee ; Brown sandy limestone of Caiycoceras choffati zone near Odium. - 84 - Distribution ; This species is known to occur in the Upper Cenomanian of France, Japan and Madagascar. Calycoceras bath./omphalum (Kossmat) PI. X, Fig. 5 1897 Acanthoceras faathyomphalum Kosijaat ; Kossmat, p. 100, pi. 11, figs.4 a,b,c 1937 Calycoceras (Eucalycoceras) bathyomphalum (Kossmat) : Collignon, p. 71, pi, 2, fig. 1 1951 Calycoceras bathyomphalum (Kossmat) : Wright & Wright, p .24 1964 Calycoceras (Lotzeltes) bathyomphalum (Kossmat) : Wiedmann, ( in Kennedy, 1972) Material : One specimen, Plesiotype Od 15 Dimensions: Diameter of shell 100.0 mm (1) Breadth of whorl section 52.0 mm (0„52) Height of whorl section 41.0 mm (0.41) Umbilical diameter 33.0 uitn (0.33) B/H =1.26 Remarks : Rather small shell; depressed, rounded cross section* venter broad, moderately arched; evolute; urabilicus deep with steep walls; inner whorls spinose’, strongly ornamented/with ribs long and short, separated by wider interspaces; short ribs of different lengths; weakM tuber- culation and d£JO)4^ of umbilical tubei^cles; later whorls with numerous ribs and suture similar to C. newboldi help to place - 85 - this material in C, bathyomphalum (Kossmat) (Kossmat, 1897, p. 100, pi. 11, figs. 4 a,b,c) from Middle ^tatur group of South India. The present species is grouped with Euomphaloceras aberrans (Kosnwat) under the subgenus Lotzeites Wiedmann by Kennedy (l97l) but the present author agrees with Matsumoto (i960) in placing it in Calyooceras as it does not show any bifurcation of ribs at the ventrolateral shoulders. Occurrence : Brown clayey limestone of Acanthoceras rhot cmagens e zone near Odiun. Distribution ; This species is known from Upper Cenomanian of Southern France, Southern England (Cenomanian rhotomagense zone) and Madagascar. Calycoceras pauclnodatuni (Crick) PI. XIII, Figs. 1, 4 1857 Ammonites navicularis non Mantell : Sharpe, p. 39, pi, 18, figs. 3, 5 only 1900 Calycoceras naviculare (Sharpe) : ilyatt, p. 589 1907 Acanthoceras paucinodatum Crick : Crick, p. 203, pi. 13, figs. 3, 3a 1926a Metacalycoceras subgentoni Spath : Spath, p. 83 1937a Calycoceras subgentoni (Spath) : Spath, p. 279. 1951 Calycoceras subgentoni (Spath) : Wright & Wright, p. 25 1951 Calycoceras paucinodatum (Crick): Wright & Wright, p. 25. - 86 - p.77. 1971 Calycoceras paucinodatum (Crldc ) : Kennedy,|^ pi. 9, figs. 4ayc PI. 40, fig. 4; pi. 41, fig. 3; pi. 43, fig.2; 4 a,b; pi. 44, figs. la-c, 2a-c; pi. 45, figs.l, 2, 3a,b, pi. 46, figs. la^c, pi. 47, figs.6a,b, 7, 8a, b. 1972 Calycoceras (Gentonlceras) cf. paucinodatum (Crick) : Thomel, p.73, pi.24, figs. 1-3. Material : Two specimens, Plesiotype Ot 32/70 Dlmen sions ; Diameter of shell : 80.0 mm (l) Breadth of whorl section; 41.0 mm (0.5l) Height of whorl section : 36.0 mra (0.45) Umbilical diameter : 22.00 mm(0.27) B/H =1.13 Remarks : Small shell; umbilicus small, deep, with steep walls; cross section slightly depressed with a moderately arched venter and slightly convex sides; inner whorls with strong, tubercles, umbilical tubercles persistent throughout, siphonal tubercles tend to disappear before the inner and outer ventro-laterals; numerous ribs characteristically bifurcating at umbilical tubercles in inner whorls, while long and short on outer whorls and sutures similar to Calycoceras newboldi. make the present material placoable in Calycoceras paucinodatuin. It is interesting to note that this species erected by Crick was shown by him to be conspecific with Sharpe's C. navirulare (Sharpe, 1857, pi. 8, figs. 3, 5 only) which was later chosen by Spath (l926a) as type for his species - 87 - subgentonl. In recent years Wright 4 Wright (l95l) and Thomel (1972) have still preferred to recognize Spath’s species, while, Kennedy (l97l) has agreed with Crick in considering them conspecific. The present author agrees with Kennedy, Occurrence : Bluish limestone of Acanthoceras rhotomagense zone and brownish clayey limestone of Calycoceras choffati zone near Odium, Utatur. Distribution : This well known species is recorded to occur from Middle Cenomanien of England, France, East Africa, Madagascar, etc. Genus : EucaflL ycoceras Spath, 1923 Eucalycoceras Spnth is represented by four species in the present collection. Species found assignable to this genus from South Indian Upper Cretaceous rocks were reported by Stoliczka (l865) as Ammonites rhotomagensis Defrance and Ammonites harpax Stoliczka. Later Kossmat (1897) transferred them to Acanthoceras. Spath in 1923 erected the genus Eucalycoceras with the type Acanthoceras pentagonum Jukes - Browne from Bed C of the Cenomanian limestones near Lyme Regis (Dorset) England. In recent years this genus has been revised and some Luropean authors e.g. Kennedy (l97l) and Thomel (1972) consider that the scope of this genus should be restricted to the pentagonum group only. On Stoliczka*s harpax group opinions - 88 - have differed among recent workers. Some like Wiedmann (1959) have preferred to place it under Protapanthoceras while Thomel (1972) has suggested a new name Pseudocalycoceras taking Stoliczka's Ammonites harpax as its type. The various morphological differences used as bases for erecting the new genera from this group do not seem s^ound in the light of the study of the present collection. Hence the harpax group of Stoliczka is presently placed in Eucalycoceras Spath rather than any of the new gemera proposed; detailed remarks on it are given under Remarks on Eucalycoceras harpax (stoliczka) further below. Eucalycoceras species in our collection appear in the Upper part of Acanthoceras rhotomagense zone and become important in the Calycoceras choffati zone. Eucalycoceras harpax (Stoliczka) PI. XII, Figs. 2, 4 1865 Ammonites harpax Stoliczka : Stoliczka p. 72, pl. 39, figs. 1, la, lb only. 1897 Acanthoceras harpax (Stoliczka) : Kossraat, p. 13 1920 Acanthoceras harpax (Stoliczka) : Taubehhaus p. 16 1931 Acan thoc eras harpax (Stoliczka) : Basse, p. 38 1937 Protacanthoceras harpax (Stoliczka) : Collignon, p. 33. 1940 Protacanthoceras harpax (Stoliczka') ; Fabre, p. 223-225. - 89 - 1959 Protacanthoceras harpax (Stoliczka) ; Wiedmann, p. 711, 1962 CalycQceras harpax (Stoliczka) ; Avnlmelech et Shoresh, p • 532 1972 Psendocalycoceras (Pseudocalycoceras) harpax (Stoliczka) ; Thomel, p. 88 Material ; Several specimens most of them fragmentary, Plesiotype Kn 6 Dimensions : Diameter of shell : 73.00 mm (l) Breadth of T*orl section: 21.00 mm (0.28) Height of whorl section: 29.00 ram (0.39) Umbilical diameter : 22.5 mm (0.30) B/H =0.72 Remailcs : With shell small, compressed, moderately evolute; umbilicus not deep with steep walls; narrow venter, feebly arched; cross section almost rectangular with rounded corners; ornamented with 30 strong alternating long and short flexuous ribs separated by wider interspaces; seven rows of tubercles which except the umbilicals, have a tendency to become clavate; siphonal and umbilical tubercles strong; siphonal tubercles persistent, our specimens agree fully with Stoliozka’s Ammonites harpax (in parts) from the Middle and Upper Utatur group near Kunnam, Odium, Munglepaudy, etc. Based on Stoliczka’s Ammonites harpax as the type, Thomel (1965) erects a new genus Pseudocalycoceras distinct fiom Eucalycoceras as having a larger umbilicus fewer (25-30) flexuous. - 90 - rursiradiate ribs; strong umbilical bullae twisted into *S’ shape; and 3-5 rows of tubercles on the venter, with upper ventrolateral and siphonal tubercles closely spaced on early whorls, and not tending to disappear in the adult stage. However, a close comparison of our material with Stoliczka’s materialin the G.S.I. collection shows that by number of ribs per whorl, conical umbilical tubercles becoming bullate and only slightly twisted into ’S* shape at adult stage, their spacing rexnaining the same at all stages of shell growth with persistence of siphonal tubercles till the end and total disappearance of other ventrolateral tubercles at adult stage, our present material as well as Stoliczka's Ammonites harpax go better under Eucalycoceras rather than Thomel’s Pseudo- calycoceras; because none of the characteristics are so well marked as are typical of Thomel’s genus. This species had been assigned to Protacanthoceras by Collignon (l937) and Wiedmann (1959), which in the present author’s opinion is incorrect, because ventral tubercles are not typically closely spaced and do not form cheverons as in Protacanthoceras. There are some speciir.ens in the present collection which are mostly similar to Eucalycoceras harpax, but also show a much more squarish cross section and resemble species of newboldl group. They are for the present placed in - 91 - Eucalycoceras harpax; but further material and a detailed consideration may prove that E. harpax has developed out of newboldl stalk through some types like these specimens. Occurrence : Brownish clayey limestones of Acanthoceras rhotomagense zone and Calycoceras choffati zone from the neighbourhood of Kunnam, Odium, Munglepaudy, etc. Distribution : This species is fairly widely distributed bein^^ recorded from Cenomemian of Madagascar, Upper Cenomanian of France, Spain, Portugal and Israel. Eucalycoceras pentaponum (Jukes-Browne) PI. XII, Fig. 3 1865 Ammonites harpax Stoliczka : Stoliczka p, 72, pi. 38, fig, 2 only 1896 Acanthoceras pentagonus Jukes->»Browne : JukeBrowne & Hill, p. 156, p i.5, figs. la, b 1897 Acanthoceras pentapfonus Jukes-Browne : Kossmat, p, 14, pi. 4, figs. 4a-c 1923 Eucalycoceras pentap;onum (Jukes-Browne) ; Spath, p. 144 1940 Eucalycoceras cf. pentagonum (Jukes-Browne): Fabre, p.299 1951 Eucalycoceras pentagonum (Jukes-Browne) : Wright & Wright, p. 26 1964 Eucalycoceras pentagonum (Jukes''Browne) : Gollignon, p .138, pi.370, fig. 1610 1965 Eucalycoceras aff. pentagonum (Jukes-Browne): Gollignon,p«12 - 92 - 1971 Eucalycoceras pentagonum {Jukes*Browne) : Kennedy, p. 81, pi, 48, figs. la,b;2, 3 a,b; 4 a,b; 5 a, b; 6 a, b; pi. 49, figs. 1 a-c. 1972 Eucalycoceras (Eucalycoceras) pentagonum (Jukes^Browne & Hill) : Thomel, p. 83, pi. 28, figs. 1, 10. Material ; Several specimens; Plesiotype Od 74 Dimens ions Diaaiete r of shell 117.00 mm (l) Breadth of whorl section 44.00 mm (0,37) Height of whorl section 47.5 mm (0.40) Umbilical diameter 35.5 mami (0.30) Breadth of whorl section at i whorl 32.3 ram (0.27) Height of whorl section at whorl : 36.4 mra (0.3l) b/H = 0.92, B/II at i whorl =0.89 Remarks : Shell moderately evolute, compressed; cross section oval with flat sides*venter well rounded, narrow in the early stages, tending to be broad on the body whorl; umbilical shoulder rounded; umbilicus not deep with steep walls; ribs originate from umbilical tubercles in twos or threes, both long and short, 50-60 per whorl, on the adult shell, sharper on early whorls, later tending to become flat topped with narrower interspaces; in all seven rows of tubercles, 5 placed on broad venter all equidistant but siphonal stronger making the cross section pentagonal; and the umbilical tubercles conical in early whorls, tending to become bullate, help in Identifying - 93 - our material as Eucalycoceras pentagonum from the Upper Cenomanlan of England, Occurrence : From brownish clayey limestones of Acanthoceras rhotomagense. Calycoceras choffati and Mamaites conciliatum zones near Kunnam, Odium, Munglepaudy, etc. Distribution : The holotype of this species comes from Bed C of the Cenomsnian limestone near Lyme Regis (Dorset) England. This species is fairly widely distributed and has been reported from Frotacanthoceras .iacobi zone of Cenomanlan of Spain and Portugal; Cenomanlan of Algeria, Upper Cenomanlan of France, Japan; from zone of Mantelllceras and Calycoceras newboldi in H'adagascar. Eucalycoceras collignoni (Fabre) PI. XIV, Figs. 1,2 1940 Protacanthoceras collipnonl Fabre : Fabre, p. 225, pi.7, figs. 7, 8. 1972 Eucalycoceras (Eucalycoceras) collignoni (Fabre) : Thorne 1, p. 85, pi. 27, fig. 7 Material : One specimen, Plesiotype Sr 8/70 Dimensions; Diameter of shell 125.00 mm (l) approx. Breadth of whorl section 34.00 mm (0,27) Height of whorl section 49.00 mra (0.39) Umbilical diameter 40.00 mci (0 .3 2 ) Breadth of whorl section at ^ whorl : 22.00 mm (0.17) - 94 - .Height of whorl section at I whorl : 35.00 mm (0.27) b/H = 0.69, B/H at J whorl =0.62 Remarks : Shell compressed, evolute; cross section oval with arched, broad venter, sides flat; umbilical and ventrolateral shoulders well formed; numerous rursiradiate ribs, long and short, former originating at strong conical umbilical tubercles; intercalating short ribs vary in number; ribs tend to become rectiradiate bn body chamber, sharper and stron? and more so on venter; in all seven rows of tubercles, ventrolateral tubercles equally spaced, clavate and suture similar to Eucalyooceras pentagonum. help to identify our material as Eucalycoceras collignoai (Fabre) eventhough there are some slight differences such as larger number of ribs, stronger and conical umbilical tubercles and larger number of intercalary short ribs. This species bears a strong resemblance to Eucalycoceras pentagonum on the one hand and Eucalycoceras harpax on the other. Occurrence : Ferruginous clayey sandstone of Calycocer&s choffati zone at Siruganur. Pis tribution : This species is recorded from Upper Cenomanian of Basse Provence occidentale and chaines des subalpine meridlonale outside South Indian basin. Eucalycoceras pentagonum and Eucalycoceras harpax to which the present species bears close affinities and with both of which - 95 - it is associated here have a wide geographic distribution duilng the Middle and Upper Cenomanian e.g. in England, France, NSadagascar, Portugal, Israel, etc. Eucalycoccras gothicum (Kossmat) PI. XII, Figs. 1, 5 1865 Ammoni tes rhotomagensis var. coiapressa iitoliczka ; Stoliczka, p. 69, pi. 34, fig. 5 1895 Acanthoceras gothicuia Kossmat ; Kossmat, p. 69, pi, 25, Figs. 3 a-c 1907 Acanthoceras cf. gothicum Kossmat : Pervinquiere, p. 261 1923b Acanthoc eras gothicum Kossmat : Spath, p. 144 1925 Acanthoceras gothicum Kossmat : Diener, p. 261 1940 Eucalycoceras of. gothicum (Kossmat) : Fabre, p. 228. Mate rial ; Several specimens, Plcsiotype Kn 5 Dimensions; Diameter of shell ; 71.1 mm (l) Breadth of whorl section: 31.5 mm (0.44) IJeight of whorl section: 37,0 mm (0.52) Umbilical diameter : 20.7 mm (0.29) Breadth of whorl section at whorl : 18.6 ram (0.26) Height of whorl section at i whorl : 22.0 mm (0.30) B/H = 0.85 B/H at i whorl 0.85 Remarks : Shell compressed, moderately involute; cross-section rectangular with sides flat, venter arched; numerous (40) ribs - 96 - arising from umbilical tubercles in tows or threes, long and short; short ribs varied in length, slightly rursiradiate; ventrolateral tubercles clavate, siphonal and umbilical conical; 12 umbilical tubercles on the last whorl, projecting in^to the umbilicus; and sutures similar to the E. pentagonum help us in placing our material in Eucalycoceras gothicum (Kossraat). The only difference is that our specimens show slightly flatter sides than Kossmat’s specimens preserved in the G. S. I. Occurren ce : Acan thoceras rhotomagense and Calycoc eras choffati zones near Odium, Kunnam, Munglepaudy, etc. Distribution : This species is widely distributed in the Cenomaiian of England (Upper parts of rhotomagense zone and Lower naviculare zone). Franco, Tunisia, etc. Genus ; Ac an thoceras Neumayr, 1875 The genus Acanthoceras is represented by not many species in the present collection. Stoliczka had reported the occurrenct of Aiiimonites rhotomagensis Defrance in these deposits and later Kossmat transferred it to Acanthoceras newboldi Kossmat. During all these almost 100 years these two species names have been appearing in literature published on these deposits. No one, however, has looked at them critically in the light of the current diagnosis of the genus Acanthoceras. In the present - 97 - collection six species are found to represent this genus and once more the species rhotomagense Defrance is being reported to occur here as represented by its two varieties confusum and sussexiense. As this genus is highly variable in its characters it has brought lot of confusion in the nomenclature of the type species as well as of sotie of its other important species. Earlier it was diagnosed to have strong ornamentation with tubercles dominating over the ribs, in many cases even hypernodosity having appeared (Wright, 1957, p. L414). But recent studies by Kennedy and Hancock (l970) have demonstrated that the earlier diagnosis is more correct for the middle growth stages of Acanthoceras; that on the later stages of growth the ribs become dominant over tubercles; and the genus is characterised by very little change in morphology during ontogeny. The South Indian species assigned here to the genus ■Acanthoceras are very similar to Calycoceras newboldi in some respects; but they show characters most of which permit of their being assigned to Acanthoceras. In our collection from South Indian Cretaceous the Acanthoceras population occurs restricted to the lower part of Middle Utatur Group; and though represented by small number of individuals it is chosen as a zonal guide fossil, - 98 - for the Lower part of Middle Utatur Group which is named as Acanthoceras rhotomagense assemblage zone. Reasons for such a choice are given in Chapter IV dealing with Comments on Stratigraphy of these deposits. Acanthoc eras rhotomagense var. confusum (Gueranger), A, rhotomagense var. sussexiense (Mantell) and A. sanctorum Matsumoto are being reported here for the first time from the Upper Cretaceous rocks of South India. Acanthoceras hunteri Kospmat a form of which the position under this genus has been doubted by Matsumoto (1969) is considered to be related to Acanthoceras rhotoiaagense var. confusum (Gueranger). Acanthoceras matsumotoi sp. nov, PI. XV, Figs. 1, 2 Material : Several specimens, Holotype Od 5/70 Dimensions ; Diameter of shell : 180.0 mm (l) Breadth of whorl section : 89.0 mm (0.49) Height of whorl section : 85.9 mm (0.47) Umbilical diameter : 83.6 mm (0.46) Breadth of whorl section at i whorl : 71.4 mm (0.39) Height of whorl section at i whorl ; 60,8 mm (0.33) B/H = 1,03 B/H at i whorl =1,1 - 99 - Description : Shell moderately large, evolute with fairly deep, steep walled umbilicus, The costal whorl section is squarish though slightly broader than high; the intercostal cross section is rounded, though on the inner whorls, it is squarish with flat sides. The maximum width is on the sides not particularly on umbilical edge or ventrolateral shoulder. The early growth stages are ornamented with strong tubercles and ribs; their relative dominance is difficult to decide. The later whorls definitely show strong ribs and the tubercles tend to disappear. There are umbilical, inner and outer ventrolateral and siphonai tubercles on every rib. In the earlier whorls all the tubercles are strong, the siphonai, and outer ventrolaterals are clavate while the inner ventro lateral tubercles are conical. The siphonai tubercles disappear earliest followed by the outer ventrolateral ones. The inner ventrolaterals and umbilical tubercles, however, persist though much weakened, till the last part. The inner ventrolaterals are often weak on ventrolateral shoulder. The ribs have symmetrical slopes and are about 20 on the last whorl but are more numerous on the earlier whorls where they are broader than the interspaces while on the last whorl interspaces tend to be very much broader. The ribs are reoti- radiate but on some portion at the beginning of the body whorl they are somewhat flexuous and anteriorly bent on the venter. On the body chamber they become slightly raised as to appear like collars. - 100 - The sutures are simple, Acanthoceras type. Remaiics : The present species is very much similar to Acan thoceras rhotomagense var, confusum (Gueranger) with which it is associated In our collection, but differs in having much faster rate of growth, a more evolute and slightly stouter shell. Also its umbilicus is deeper and the intercostal section more rounded. Occurrence ; Light brown clayey limestone of Ac anthoceras rhotomapense zone near Odium and Kunnam. Acanthoceras intermediatum sp. nov. PI. XIII, Pig. 3 Material : Several specimens, Ilolotype Od 22/70 Dimensions : Diameter of Abell : 64.5 mm (l) Breadth of whorl section:37.1 mm (0.57) Height of whorl section: 33.5 mm (0.5l) Umbilical diameter : 22.3 mm (0,34) Breadth of whorl section at whorl ; 23.2 mm (0.35) Height of whorl section at i whorl : 19.6 mm (0.30) b/ h =1.1 b/H at i whorl =1.1 Description : Shell moderate in size, evolute with a somewhat squarish cross section. The intercostal section somewhat Ih J/02.0 - 101 - rounded and depressed with width more than its height. The umbilicus is large, deep with steep sides. The early stages of growth show a predominance of tubercles over the ribs. The ribs are few and well separated with broad interspaces. They are stronger on the flanks than on the venter and are alternotely long and short. There are umbilical inner and outer ventrolateral and siphonal tubercles; the inner ventrolaterals are spinose while the outer ventrolaterals are conical with clavate bases. The siphonal tubercles arc clavate and fairly elongated. In the middle growth stages the ribs become numerous and remain alternating while the siphonal tubercles disappear. The umbilical tubercles become weak, so do the inner and outer ventrolaterals. In general, the ribs tend to become more prominent, interspaces being wider but not so much as in the early growth stages. The late growth stages are characteristic. The shell grows very rapidly in cross section^ Repressed intercostal section of the middle growth stage becomes square by increase of whorl height. The costal section, however, remains somewhat unchanged. The tubercles disappear except feeble umbilical ones which shift the sides. The ribs become sparse and strone and become raised on the venter, giving them an appearance of collars. There are about six to eight ribs of - 102 - the longer type on the last half wborl, the short ones having disappeared. Sutures are Acanthooeras type. Remarks : This species is comparable to Acanthooeras rhotomagense var. confusum which is represented in the present collection, but differs from it in smaller number of ribs on the last whorl, a narrower and deep umbilicus and early disappearance of ventrollateral tubercles. The rapid growth of the shell makes this species comparable to Acanthooeras matsumotol in our collection but differs in having a depressed Intercostal whorl section In the middle growth stages and a smaller number of ribs on the last whorl. The present species shows a peculiar combination of morphological characters of Mantelllceratinae and Acanthoceratlnae, The early growth stages show prominence of tubercles over ribs ( an Acanthooeras character) while the middle aid later growth stages show a prominence of ribs over tubercles ( a Mantelliceras character''. Occurrence : Light brown clayey limestone of Acanthooeras rhotomagense zone near Odium. Acanthooeras rhotomagense var. sussexlense (Mantell) PI. XVII, Figs. 1, 2 - 103 - 1822 Amtnonites sussexiense Mantell : Mantell p. 114, pi. 20, fig. 1, pi. 21, fig. 10 1854 Ammonites rhotomagensis Defrance : Sharpe p. 33, pi. 16, figs. la-c, 3a, b only, 1863 Ammonites rhotomagensia Brongniart : Pictet pi. 2, figs. la-c only. 1878 Acanthoceras rhotomagensis Brongniart : Bayle pi. 63, figs. 1-3 only 1951 Acanthoceras vectense Spath : Wright & Wright, p. 28 1951 Acanthoceras sussexiense (Mantell) : Wright & Wright, p. 28 1963 Acanthoceras mirialamplense Wright : Wright, p. 606, pi. 84, fig. 3, pi. 85, fig. 1 1970 Acanthoceras rhotomagense var. sussexiense (Man tell) ; Kennedy & Pancock p. 472, pi. 89, fig, 2, pi, 91, figs. 1,2, pi.92, figs.l, 2; text figs. 3, 4, 5, 6a. Material ; One specimen; Plesiotype Od 13/70 Dimensions : Diameter of shell : 194.0 mm (l) Breadth of whorl section: 82.0 mm (0.42) Height of Tvhorl section : 80.0 mm (0.4l) Umbilical diameter 56.0 mm (0.28) Breadth of whorl section at i whorl 68.0 mm (0.35) Height of whorl section at i whorl 58.0 mm (0.29) B/H = 1.02 B/H at i whorl =1.17 Remarks : The present specimen is a septate part of the shell of which some part of outer whorl is broken aid lost. The inner - 104 - whorls, however, are visible and well preserved. Under these conditions placing this specimen under the present form is rendered possible by its -Acanthoceras type of suture, broad rounded venter, squajfrish cross section, moderately evolute with well rounded umbilical and ventrolateral shoulders and umbilicus moderately large and deep with steep walls; also helpful are the early and middle growth stages showing typical ornamentation consisting of numerous alternating long and short ribs, 015 flexuous, each long rib bear|t umbilical, inner and outer ventro lateral and a siphonal tubercle, all being conical and nearly of the same strength; with growth the siphonal tubercles dis appearing very soon followed by inner and outer ventrolateral tubercles, umbilical tubercles, however, persisting though weak, the cross section undergoing a slight change to become more sfluarish and the sides remaining somewhat flat. The present material shows sotne minor differences as compared to the English form. Thus our specimen shows a slight Ij^ smaller umbilicus at comparable diameter and a somewhat better rounding of the ventrolateral shoulder. The present material shows some similarity towards Acanthoceras subflexuosum Spath from the Cenomanian (rhotomagense zone) of England, but has a somewhat thicker cross section; similarly it can by its much depressed cross section be distinguished from Acanthoceras vectensiforme Thomel from Middle Cenomanian of Chaines subalpines Meridionales,France - 105 - Occurrgnce : Brown sandy lines tone of Acanthoceras rhotoma/?ense zone near Odium. Dlstrlbution : This species has a very wide geographic distribution in the Middle Cenomanian of England, France, Madagascar, etc. Acanthoceras rhotomagense var. confusum (Gueranger) PI. XVI, Figs. 1, 2 1856 Ammonites hippocastanum Sowerby : Sharpe p. 37-38, pi. 17, figs. 3a-b, 4 1863 Ammonites rhotomajgensis Brongniart : Pictet pi. 2, figs,2a-c, 3 only 1867 Ammonites conjCusus Gueranger ; Gueranger, p. 5, 6, pi, 2, fig. 4, pi. 3, fig. 1, pl. 8, fig. 1 1970 Acanthoceras rhotomagense var. confusum (Gueranger) ; Kennery & Hancock, p.478, pl. 94, figs. 1-4 Material : One specimen, Plesiotype Od 121/70 Dimensions : Diameter of shell 255.0 ipip (1) Breadth of whorl section 88.6 mm (0.34) Height of whorl section 83.6 lam (0.32) Umbilical diameter 98.6 mm (0.38) Breadth of whorl section at i whorl : 78.5 ram (0.30) Height of whorl section at 1 whorl : 64.9 mm (0.25) B/H = 1.06 B/H at i whorl =1.2 - 106 - Remaiics : Shell large, evolute, Intercostal section squarish with rounded corners and broadly arched venter; a slow rate of growth of shell except on body whorl; early whorls with dominant tubercles and body chamber with ribs; siphonal tubercles disappearing earlier than other tubercles; ribs 20 on outer whorl, all long, rectiradiate and raised like collar on body chamber; ribs on inner whorls numerous both long and short and suture simple with few elements help in identifying the present material as Acantbocexas rhotomagense var. confusum (Oueranger) from the upper part of the sands with Perma lanoeolata (Lower part of Middle Cenomanian) in the Sarthe, Jhe difference lies in our specimen having a feebler ornament on earlier whorls, inner ventrolateral tubercles not spinose and much larger number of ribs on the inner whorls. Occurrence : Whitish clays of Aotfnthoceras rhotomagense zone near Odium. Distribution : This species is known from rhotomagense zone of Middle Cenomanian from England » d France. Acanthoceras sanctorum Matsumoto PI. XIII, Fig. 5 1966 Acanthoceras sanctorum Matsumoto : Matsumoto, p. 43-52, pi. 1-4. Material : One specimen, Plesiotype Od 3 - 107 - Dimensions : Diameter of shell 169.0 mm (l) Breadth of whorl section 75.0 mm (0.44) Height of whorl section 70.0 mm (0.4l) Umbilical diameter 55.0 mm (0.32) Breadth of whorl section at i whorl : 44.0 mm (0,26) Height of whorl section at i whorl : 44.0 mm (0.26) B/H = 1,07, b/H at i whorl = 1.00 Remarks : Though a solitary septate portion of the shell is available it is pieced under Matsumoto's species because of its agreement in most of the characters, such as its squari-sh cross section \9itli somewhat rounded venter; middle growth stages with numerous ribs, long and short, rectlradiate on sides but slightly anteriorly projected on the venter; shorter ribs without umbilical tubercles and disappearing on later stages; the ventrolateral tubercles on long ribs getting sharper in later stages; the siphonal tubercles disappearing early; the interspaces broader than ribs, and tending to be still wider on later stages and Acanthoceras type suture. The present specimen is placed under this species rather than under Acanthoceras turneri White from the Middle Utatur group in South India which it otherwise resembles but for disappearance of intercalary short ribs and the siphonal tubercles. - 108 - Occurrence : Pale brown clays of Acanthoceras rhotomajgense zone near Odium. Pistribution : This species is known from the Cenomanian of Japan. Acanthoceras hunterl Kossmat PI. XVIII, Fig. 1 1897 Acanthoceras hunter! Kossmat : Kossmat, p. 9, pi. 3, fig. 4 Material : One specimen, Plesiotype Od 63 Dimcnsions: Diameter of shel] : 230.0 mm (l) Breadth of whorl section: 91.0 mm (O.S9) Height of whorl section : 82,0 mm (0.35) Umbilical diameter : 8S.0 mm (0.38) Breadth of whorl section at i whorl : 78.0 mm (0.33) Height of whorl section at i whoU : 66.4 mm (0.28) B/H =1.1 B/H at i whorl = 1 . 7 Remarks : Shell large evolute, with squarish cross section; a flat, or slightly rounded venter; uiiibilicus moderately deep with steep sides; slow rate of growth of the shell; ribs strong, numerous (SO), rectiradiate, long and short on earlier whorls only; jj)ec0mingj^ll| long by diameters 82-100 mm; interspaces much wider than ribs; inner ventrolateral tubercles spinose,* siphonal tubercles disappearing first; and sutures not well presei'ved but simple Acanthoceras type help in identifying the - 109 - present material as Aoajithoceras hunterl Kossmat, though it shows larger number of ribs. The inclusion of this species in Acanthoceras has been questioned by Matsumoto (1969) but the present author feels that according to the diagnosis of Acanthoceras given by Kennedy & Hancock (1970), the present assignment seems to be prope r. Thomel (1972) has proposed a new genus Guerangericeras with Acanthoceras rhotomagense var. confusum (Gueranger) as its type to which he has assigned this species. The present author agrees with Kennedy & Hancock in considering confusum a variety of Acanthoceras rhotomagense for the present, as the material in the present collection is not sufficient to enable a critical study. Occurrence : Whitish clayey limestones of Acanthoceras rhot omagense zone from near Odium. Genus : Euomphaloceras Spath, 1923 Euomphaloceras Spath is represented by only three species in the present collection and that too with a very small number of specimens in each species. The distinction between various species by Euomphaloceras especially E. cunnlngtoni (Sharpe) and E. meridionale (Stoliczka) ~ 110 - has been a subject of some difference of opinion, Wright (1963) and some European authors e.g. Kennedy (l97l) have considered the two species synonyms; while Matsumoto (1969) has regarded them as separate species. The present author prefers to follow Matsumoto in regarding them as two distinct species. Suomphaloceras aberrans (Kossmat) is again a species which has been the subject of some controversy. It has been designated by Wiedmann (1959) as the type of Lotzeites Wiedmann a subgenus of Calycoceras; but as rightly pointed out by Matsumoto (1969) it is better assigned to Euomphaloceras. His reasons for this are given further below under the remarks on Euomphaloceras aberrans (Kossniat). There has been some doubt about occurrence of this genus in the South Indian Cretaceous deposits; but now from our work it can be said with certainty that this genus does occur in South Indian Cretaceous beds and is represented by E, ounningtoni (Sharpe) and E, meridlonale (Stoliczka) in the Upper part of the Acantheceras rhotomagense zone, and E. aberrans (Kossmat) in the Calycoceras choffati zone. Euomphaloceras cunningtoni (Sharpe) FI. XIX, Figs. 1, 2 1855 Ammonites cunningtoni Sharpe : Sharpe, p. 35, pi. 15, figs. 2a-c 1897 Acanthoceras cunningtoni var, corunata Kossmat : Kossmat, p. 11, pi. 5, figs. la-c - Ill - 1907 Acanthoceras cunnlngtonl (Sharpe): Pervinqulere, p. 227, pi. 15, figs. la-c 1933 Acanthoceras cunnlngtonl (Sharpe): Colllgnon, p. 63, fig s .2,3 1944 Cunningtonloeras holtkeri Eml : Emi, p. 479, pi, 11. 1951 Euomphaloceras euomphalum (Sharpe) : Wright & Wright, p .29 1957 Euomphaloceras c f . euomphalum (Sharpe) : Matsumoto ^ a l . p. 34, pi. 15, fig.3, non-fig. 13 1963 Euomphaloceras cunnlngtonl (Sharpe) : Wright, p. 607, p i .68, fig. 2, pi. 89, fig. 9 1971 Euomphaloceras ounningtoni (Sharpe) : Kennedy, p. 92, pi. 60, figs. la,b, pi. 61, figs. 2a-b Material ; One specimen, Plesiotype Od 172/70 Dimensions: Diameter of shell : 185.0 mm (l) 105.0 mm (l) Breadth of whorl section:75.0 mm (0.40) 55.0 mra (0.52i Height of whorl section : - - 42.5 ram (0 .4 0 ’ Umbilical diameter :54.0 mm (0.30) 34.0 mm (0.30 B/H = 1.30 B/H = 1.29 Remarks : Shell stout; rectangular intercostal section with rounded com ers; venter flat or slightly arched; umbilicus moderately large, deep with steep walls; strongly ornamented with ribs and tubercles; in all 7 ravs of tubercles, umbilical, inner and outer ventrolateral, siphonal; siphonal tubercles clavate on faint mid ventral keel; inner ventrolateral ones strong, spinose, pointed obliquely to the plane of coiling', 14 ribs on outer whorl, moderately strong, slightly rursiradiate. - 112 - from inner ventrolateral tubercles they take a slight forward bend; intercalated with short ribs on inner whorls only? bifurcation at inner ventrolateral tubercles only faintly indicated on early whorls,and faint ventral constrictions, help us in placing this material in Euomphaloceras cunningtonl (Sharpe). Our material is similar to forms transitional between Acanthoceras and Euomphaloceras as described and figured by Kennedy & Hancock (l970) and also bears a close resemblance with Acanthoceras latum (Crick) as regards its ventral ornament. Occurrence : Brown sandy limestone from Upper Acanthoceras rhotomagense zone near Odium, Distribution : This species 1% found to occur in the Middle Cenomanian of England, France, Madagascar, Morocco, etc. Euomphaloceras meridionale (Stoliczka) PI. XX, Figs. 1, 2 1865 Ammonites meridlonalis Stoliczka : Stoliczka, p, 76, pi.41, figs. l,la, lb, Ic 1907 Acanthoceras meridionale (Stoliczka) ; Pervinquiere, p. 278, pi. 15, ligs. 2-6 1963 Euomphaloceras cunningtoni var. meridionale (Stoliczka) : Wright, p.607, pi. 88 - 113 - 1969 Euomphalocerasmeridiopale (Stoliczka) : Matsumoto et^ a l . p. 272, pi. 33, figs. 1,2, pi.34, fig. 1, text fig. 6 1971 Euomphaloceras cunnlngtonl var, merldlonale (Stoliozka): Kennedy, p, 92, Material : One speolmen, Pleslotype Od 6/70 Dimensions ; Diameter of shell : 123.3 mm (l)) Breadth of -whorl section: 74.0 mm (0,60) Height of «horl section : 53.2 mm (0.43) Umbilical diameter : 40.0 ram (0.33) Breadth of whorl section at i whorl ; 42.0 mm (0.34) Height of whorl section at i whorl : 32.5 ram (0.26) B/H = 1.39 b/ h ati whorl = 1 .2 9 Remarks : Shell moderately evolute, depressed; whorl section rectangular with sides flat, venter broad and flat; strongly ornamented with ribs and tubercles; inner ventrolateral tubercles spinose and strong, pointing at right angles to the plane of coiling; outer ventrolateral and siphonal feebler and twice the number of inner ventrolateral ones; siphonal tubercles disappearj, on adult shell; ventrolateral tubercles fuse to form a horn on the last parts of the shell*, ribs strong rursiradiate,' ribbing pattern variable, bifurcating both at umbilical and inner ventrolateral tubercles; slight ventral constrictions and suture like Acanthoceras make our - 114 - material plaeeable in Euomphaloceras merldionale (Stoliczka) from Middle TJtatiir gronp at Odium. Recent workers e.g. Wright (l963), Kennedy (1971) have preferred to treat this species, conspecific with Euomphaloceras Gunningtoni (Sharpe), while, Matsumoto (1969) has preferred to recognise its separate identity as this species shows a characteristic horizontally pointed inner ventrolateral tubercles, show early disappearance of siphonal tubercles and general conical nature of ventral tubercles. The present author agrees with Matsumoto (1969) in recognising it as a separate species. Occurrence : Brown sandy limestone from Upper Acanthoceras rhotomagense zone near Odium. Distribution : This species is known to occur in Middle Cenomanian of England, Japan, Australia, France, etc. Euomphaloceras aberrans (Kossmat) PI. XVIII, Figs. 2,3 1897 Ac ant hoc eras aberrans Kossmat : Kossmat, p. 202, pi. 24, figs. 4a-c 1951 Euomphaloceras aberrans (Kossmat) : Wright & V?right, p. 29 1959 Calycoceras (Lotzeites) aberrans (Kossmat) : Wiedmann, p. 7i 1969 Euomphaloceras aberrans (Kossmat) : Matsumoto e ^ ^ . , p.27S 1970 Calycoceras aberrans (Kossmat) : Kennedy, p. 70 - 115 - 1971 Caiycoceras (Lotzeltes) aberrans (Kossmat) : Kennedy, p .78, pi. 37, figs. 4a-c; pi. 47, figs. 2a, b Material : One specimen, Pleslotype Kn 186/72 Dimensions ; Diameter of shell : 33.0 mm (l) Breadth of whorl section:25.5 mm (0.77) Height of whorl section: 18.4 mm (0.55) Umbilical diameter : 13,0 ram (0.39) Breadth of whorl section at i whorl : 20.5 mm (0.32) Height of whorl section at i whorl : 9.5 mm (0.28) b/H = 1.38 B/H at i whorl = 2.1 Remarks : Shell small, evolute, depressed with deep umbilicus; ornamented with strong ribs aid tubercles; ribs long and short; '*5 long ribs bifurcat^ on inner ventrolateral and umbilical tubercles, bent forward on broad venter: interspaces as broad as ribs; slight ventral constrictions; on inner whorls indica tions of outer ventrolateral and siphonal tubercles, and inner ventrolateral tubercles spinose are characters which help to identify the present material as EuomphalooBras aberrans (Kossmat) from the Utatur gioup at Odium. This ^ e c ie s of Kossmat has been of interest as regards its proper generic position. V/iedmann (1959) has placed it ioiLotzeites subgenus of Calycocoras on the basis of its general similarity of ornament. Later workers, e .g . Kennedy (l970),etc. - 116 - have prelerred the same placement. However, Matsumoto et a l . (1969) have placed it in Euomphaloceras on the basis of bifurcation of ribs at the ventrolateral shoulders and they have opined that multiplication of ribs by bifurcation both at umbilical tubei"cles and ventrolateral tubercles is chara cteristic of Euomphaloceras. Calycoceras bathyomphalum has a similar appearance but shows multiplication of ribs at the umbilical tubercles only. The suture too slightly differs from that of Calycoceras in having a broad shallow first lateral lobe (Kossmat, 1897, Jl;,.'.24,G^lg’. .4 c ). The author feels that the present species should be placed in Euomphaloceras as it * ows bifurcation of ribs at »mbilical and ventrolateral tubercles, faint ventral constrictiory and a depressed cross-section, which has maximum breadth at the ventrolateral tubercles. Ammonites coleroonensis Stoliczka also shows multiplication of ribs onlF^&t the ventrolateral tubercles and it is very irregular; it can be easily distinguished by its bullate outer ventrolateral tubercles and a concave venter on the later stages of growth of the shell. Occurrence : Brown sandy limestone from Calycoceras choffati zone near Kunnam. Distribution : This species is reported to occur in Middle and Upper Cenomanian rocks of England, Spain, North Africa, Madagascar, etc. Everywhere, it is said to be rare. - 117 - Genus ; Kanabiceras Raeslde & Weymouth, 1931 The genus Kanabiceras Reeside & Weymouth is represented by only a few fragments in our collection belonging to only one species, and comes from the basal part of the Trichinopoly group. This genus has been diagnosed well by Matsumoto (1969) . The occurrence of this genus is taken to be in thebasal part of the Turonian and is observed almost on the same horizon wherever It is recorded; consequently its report from South Indian Cretaceous is of some interest, as it helps us in dating the basal Trichinopoly group as basal Turonian though formerly considered to be Middle to Upper Turonian. The material in the present collection is assignable to Kanabiceras septemseriatum (Cragin). Kanabiceras septemseriatum (Cragin) PI. XXI, Fig. 3 1893 Scaphites septemseriatus Cragin : Cragin, p. 240 1894 Acanthoceras ?kanabense Stanton : Stanton, p. 181, p l . 36, figs. 6-8 1927 Acanthoceras ?kanabense Stanton : Moreman, p. 95, pl. 13, fig. ^ 1928 Scaphites septemseriatus Cragin : Adiins, p. 259 1931 Kanabiceras kanabense (Stanton) : Reeside & Weymouth, p. 11 1931 Neocardioceras septemseriatum (Cragin) : Adkins, p. 60 1931 Neocardioceras n sp. Adkins ; Adkins, p. 61, pl. 2, figs.7,9 - 118 - 1942 Neocardloceras septemserlatum (Cragin) : Moreman, p, 213, pi. 33, figs. 11,12, text fig. 2 f 1957 Kanablceras septemserlatum (Cragln) : Wright, p. L414, text figs. 534-5a,b 1958 Leyelllceras stanlslansense Anderson ; Anderson, p. 247, pi, 8, figs. 5, 5a 1959 Kanablceras septemserlatum (Cragin) : Matsumoto, p. 99, pi. 24, figs. la-c, text figs. 52, 53 1963 kanablceras septemserlatum (Cragin) ; Powell, p. 316, p i .31, figs. 9, 10 1969 Kanablceras septemserlatum (Cragin) : Matsumoto £_t a l . p. 279, pi. 37, figs. 1-3 Material ; Two specimens, Pleslotype Sd 90/70 Dimensions : Diameter of shell : 41.00 mm (l) Breadth of whorl sectlon:22.0 mm (0,50) approx. Height of whorl section: 18.0 mm (0.44) approx. Umbilical diameter j 18,0 mm (0.44) approx. * B/H = 1 . 2 Remarks : The present material though fragmentary, shows characters like small size; evolute nature; depressed with convex sides and a broadly arched venter; umbilicus with steep walls; ornamented with strong tubercles aid ribs; inner ventro lateral tubercles spinose, outer ventrolaterals obliquely clavate, umbilicals bullate, siphonal tubercles forming a nodate row and more numerous than umbilical and inner - 119 - ventrolaterals; ribs numerous as broad as or wider than interspaces, long and short, rectiradiate, slightly projected forward on venter, bifurcating on umbilical as well as ventro lateral tubercles, and suture of Acanthoceras type, help in placing the present material in Kanabiceras septemseriatum (Cragin) from the Eagle Ford Formation (LOwer Turonian) of U.S.A. Occurrence : Brown calcareous sandstone of Lower Trichinopoly group at Saradmangalam. Pis trlbution : This species is known to occur typically in basal Turonian of Texas, Western Europe and Japan. Genus : Romaniceras Spath, 1923 This genus is represented in the present collection by three species and each by only a small number of specimens. Wright (1957) gave its diagnosis as "Rather evolute, circular, or oval, whorl section; differs from Acanthoceras in having nine or eleven rows of more or less equal tubercles, equidistant or not; ventrolateral tubercles may be clavate” indicating that this genus was probably a derivative of Acanthoceras. Matsumoto (1957) diagnosed it as "similar to Calvcoceras in shell form, ribbing and suture, but provided with more than one rows of lateral tubercles in addition to those preserved in Calycoceras of newboldi spinosum subgroup, - 120 - the external tubercles are weakened or obsolete on large outer whorl", thereby indicating its derivation from Calycoceras spinosum or some similar form. The present author feels that It la rather difficult to comment upon the phylogeny of this gem s on the basis of the present collection because our material is not enough for such a purpose. But as it is the generic diagnosis of Matsumoto seems to be more appropriate. Further, Matsumoto (1957) on the basis of phylogenic differences has proposed a new name Yubariceras for the multi- tuberculate forms derived from Apanthoceras and has included Ammonites ornatissimnm Stollczka in his new genus Yubariceras. What can be identified as Ammonites omatissimum Stollczka is represented in the present collection by only a solitary specimen coming from the upper part of Middle Utaturs. It is difficult to comment upon the validity of Yulrariceras Matsumoto on the basis of this solitary specimen at our disposal. Hence for the present it is placed in Yubariceras Matsunoto because of the 11 rows of tubercles it has. More material when it becomes available, »ay enable us to look into the matter more critically so as to be in a position to comment upon it. Aamonites medlicottianus Stollczka is a species which is assigned by workers outside India to either Romaniceras or Ncwboldiceras (Mourreiceras). This species is characterised by - 121 - an Acanthoceras like shell with nine rows of tubercles which makes it assignable to Romaniceras. As remarked earlier it is felt that new names proposed by Thomel (1972) for the newboldi group of species do not seem to be based on sound morphological ground and hence they have not been adopted here Romaniceras medltCQttianum was reported from North of Odium and has been thought to come from Middle Utaturs. Present author, however, has collected it from near Illuppagoody just near the contacts of Utaturs and Trichinopoly, thereby indicating for it a horizon higher than what it was formerly considered to come from. Thus till now the genus Romaniceras was known by only two species viz. Romaniceras omatlssiaum (Stoliczka) and R. medlicottianum (Stoliczka), But the present work has revealed that the former is provisionally assignable to U K W a v e Yubariceras Matsuraoto and prseon^o in these deposits two more species of Romaniceras viz. Romaniceras devarianum (d'Orbigny) and Romaniceras oldhami.. The former is being reported from South India for the first time while^ Romaniceras oldhami Is new to science. Romanlceras medlicottianum (Stoliczka) PI. XXI, Figs. 4, 5 1865 -Ammonites medllcottianus Stoliczka : Stoliczka, p, 77, pl. 43, figs. 1, la - 122 - 1897 Acanthooeras medlloottlanuni (Stoliczka) : Kossmat, p. 123 1968 Romanlceras medllcottlanum (Stoliczka) : Sastry, Rao & Mamgaln, pi. 2, figs. 3, 4 Material : One specimen, Plesiotype Yel 31 Dimensions Diamete r of shell 220.0 mm (l) Breadth of whorl section 80.0 mm (0.36) Height of whorl section 80.0 mm (0.36) Umbilical diameter 80.0 mm (0,36) Breadth of whorl section at ^ whorl 62.0 mm (0.27) Height of whorl section at i whorl I 60,0 mm (0,27) B/H = 1 . 0 B/H at i itjborl = 1,03 Remarks : Shell large, evolute, whorl section squarish; rounded intercostal section with broadly arched venter and convex sides; ornamented with strong ribs and tubercles; ribs 13 per ^ whorl, rectiradiate; in all nine rows of tubercles; umbilical bullate and feebler than lateral; lateral tubercles on bulloid bases, conical at top; placed a little above mid sides; inner ventro lateral tubercles conical; outer ventrolateral and siphonal clavate; two ventrolaterals placed close,and Acanthoceras type sutures are chaiacters which help in placing this material in Romanic eras medlicot tianum (Stoliczka) from Middle Utatur group, North of Kunnam. Occurrenoe ; Ochrey yellowish sandy limestone of Mammites conciliatum zone at 3 km from Illuppagoody towards Kolkainattum. - 123 - Romaniceras devarlanum (d'Orbigny) PI. XXII, Figs. 2, 3 1840 Ammonites devarlanus d’Orbigny ; d'Orbigny, p. 365, pl.CX 1853 Amnonitea devarianus d’Oib igny : Sharpe p. 43, pi, 19, figs. 5 a,b 1872 Ammonites devarifinus d'Orbigny ; Fritsch & Schloenbach, p. 32, pi. 7, figs. 4, 5 1913 Acantfaoceras devarianum (d'Oriigny) ; Roman & Mazeran,p. 25, p. ill, figs. 2, 2a 1939 Romaniceras deverial(d ’Orbigny) : Collignon, p. 33-37, pi. 8, figs. 2, 3, 3a, pi,9, figs. 1, la 1965 Romaniceras deveriai ( d ’Orbigny) : Collignon, p. 22, p i .384, figs. 1655. 1969 Romaniceras devarlanum (d'Orbigny) : Freund & )?aab, p. 6 Material ; Several specimens, Pleaiotype Sd 42/70 Dimensions : Diameter of shell : 89.0 mm (l) approx. Breadth of whorl section:42,0 mm (0.46) approx Height of whorl section :45.3 mm (0,50) approx. Umbilical diameter ;33.0 mm (0,37) approx B/H = 0.92 Remarks : Evolute with broad rounded venter; intercostal section rounded, with convex sides; ornamented with ioine rows of tubercles and numerous long and short ribs; umbilical and lateral tubercles bullold; ventral tubercles conical tending to become clavate on later stages of shell; ribs slightly sinuous, projected forward on venter, often bifurcattng afc - 124 - umbilical tubercles; short ribs varied in length; suture Acanthooeras type. These characters help in Identifying the present material as Romanic eras devarianum (d'Orbigny) from (Collignon, 1965, p. 22, pi. 384, fig. 1655) from Upper Turonian of Madagascar though it differs slightly in tumidity and evolute nature of shell. Wright (l95l) has indicated that English specimens of this species come from Cenomanian and that they differ slightly from d’Orbigny’s original material in some respects. d'Orbigny's original specimen is reported to belost and the species haa now several Neotypes from different parts of the world which has brought about a confusion regarding its correct identification and horizon. Occurrence : Brown calcareous sandstones from basal Trichinopoly group near Saradmangalam, Illuppagoody, Kolakainattam, etc. Distribution : This species is known from Cenomanian of England and Turonian of France, Switzerland, Madagascar, Nigeria, Israel, etc. Romanice ras oldhami sp. nov, PI. XXI, Figs. 1, 2 Material : Several specimens, Holotype Sd 94/70 - 125 - Dimensions : Diameter of shell 185.0 mm (l) Breadth of whorl section 93.0 mm (0,50) Height of whorl section 74.0 mm (0.40) Umbilical diameter 50.0 mm (0.27) B/H =1.2 Description : Shell is moderately involute; cross section is rounded with width more than the height4 venter broad; the crrc ventrolateral and umbilical shouldersj[rounded,][sides flat with steep and almost vertical umbilical walls. The shell is ornamented with moderately strong ribs and strong tubercles; the ribs are well formed, rounded and numerous, about 30 being on the outer whorl; they are long and short; the longer ones end on the umbilical walls, while, the shorter ribs reach only upto the mid sides; long and short ribs alternate, but in some specimens the shorter ribs appear to have grown and become as long as the long ribs; the ribs on the sides are rectiradiate but become somewhat projected anteriorly on the broad venter. Each long rib bears nine nearly equally spaced tubercles, an umbilical, a lateral^ two ventrolaterals, and a siphonal. Of those the two outer ventrolateral and siphonal tubercles are placed on t h e v enter^while, the inner ventrolaterals 1 the ventrolateral shoulders. All the tubercles of the three ventral rows are clavote and nearly of the same prominance; - 126 - those of slphonal row though a little more clavate tend to weaken earlier on the later stages of growth of the shell. The inner ventrolateral tubercles are conical and the strongest. The mid lateral and umbilical tubercles are bullate, the mid laterals being more prominent. Short ribs have only five tubercles, the slphonal and inner and outer ventrolaterals. Some of the shorter ribs which reach more than half the bear also lateral tubercles which are bullate but very weakly developed. The sutures are Aoanthoceras type. Remarks : The present species is siiuilar to Romanic eras devarianum ( d ’Orbigny) fron Turonian of Madagascar and also recorded from Saradraangalam, etc. in our collection^because of the nine rows of tubercles; but is distinguished by conspicuously clavate nature of ventral tubercles and a stronger development of bullate lateral tubercles. From R, uchauxlense Collignon from Upper Turonian of Madagascar, Nigeria, etc. the present species is distinguished by a wider separation of inner and outer ventrolateral tubercles and absence of tendency of inner ventrolateral tubercles to split on late stages of growth. Occurrence : Brownish, sandy limestone from the Lower Trichinopoly group at near Saradmangalam and Illuppagoody, etc. - 127 - Genus : Yubarlceras Matsumoto, 1957 Yubariceras ornatisslmum (Stollczka) PI. XXII, Figs. 1, 4 1865 Aminonltea ornatlssimus Stollczka ; Stollczka, p. 75,pi. 40 1897 Acanthoceras ornatisgimum (Stollczka) : Kossmat, pi. 6 , f i g .2 1957 Yubarlceras ornatisslmum (Stoliczka) ; Matsumoto, p. 1957 Yubariceras yubarense Matsumoto : Matsumoto, p, 27, pi. 8, figs. la,b; pi. 10, figs. la,b; pi. 11, figs. la,b; pi. 13, figs. la,b; pi. 15, fig. 1, text figs. 8, 9 1965 Yubarlceras yubarense Matsumoto : Collignon, p. 24, pi. 385, fig. 1657 Material : One specimen, Plesiotype Kn 96/70 Dimensions! Diameter of shell 114.4 mm (l) Breadth of whorl section 60.9 mm (0.52) Height of whorl section 44.6 mm (0.3S) Umbilical diameter 37.6 mra (O .33) Breadth of whorl section at i whorl 37.4 mm (0.32) Height of whorl section at whorl 32.0 mm (0.28) B/H 1.36 B/H at i whorl = 1.16 Remarks : Shell large, moderately evolute; whorl section rounded, depressed, with broad flattish venter, sides not very convex; umbilical shoulder rounded with steep walls; ornamented with strong tubercles and numerous long md short ribs. In general tubercles dominate over ribs; in all 11 rows of tubercles, an - 128 - umbilical, 2 lateral, 2 ventrolateral and a siphonal; umbilical bullae*, lateral conical but tend to be bullate on later growth stages; other tubercles somewhat cslavate and become more so on later^ stages; ribs rectiradiate, or slightly rursiradiate; and short ribs reaching upto mid H anks; j[^sutures Acanthoceras type; help in placing this material in Yubariceras ornatlssimum (Stcliczka) from Utatur group at Odium. This specimen is placed in the genus Yubariceras Matsumoto on the ground that tubercles are prominent over ribs aid hence more allied to Acanthoceras than Romaniceras which has ribs predominating over the tubercles and thus more allied to Calycoceras splnosum. With only one speciTnen available for study the author, however, feels that this material may be placed for the present into Yubariceras Matsumoto than Romaniceras Spath even though the material shows both the features at different growth stages of the shell. More material becoming available may need reconsidering the position. Occurrence : Hard greyish yellow sandy limeys Lone from Calycoceras choffati zone near Kunnam. Dlstribution : This species is known from Turonian of Madagascar and Japan, outside South Indian basin. Genus : Colerooniceras gen.nov. Type species : Ammogites coleroonensis Stoliczka, 1865 pi.37, figs. 4-6 Generic diagnosis : The shell is of moderate size, evolute with large deep umbilicus and may show variation of umbilical - 129 - QT)c) proportion between 34 to 43 j|^chfiracterised by a slow rate of growth. Cross section oval'’ to broadly circular is depressed in the later growth stages but may be angular at shoulders, almost as wide or slightly wider than high in the earliest stages of growth .['t he maximum width of the cross section at the umbilical tubercles; on the later whorls,ji may haye flat sides with almost same width of cross section at ventrolateral shoulder and umbilical tubercles. The venter i* concave betweoi bullate outer ventrolateral tubercles. But on early whorlsj^broadly arched with inner and outer ventrolateral and siphonal tubercles^ Umbilical tubercles may show weakening but inrier ventrolateral tubercles show weakening with siphonal tubercles disappearing very early during the growth of the shell. The outer ventrolateral tubercles become bullate on the later whorls but are conical on early whorls. Ribs are characteristically numerous, long and short, branched on umbilical and inner ventrolatexal tubercles. This branching may be irregular or regular. The intercalation of long and short ribs may be regular or irregular and the short ribs may show different lengths. Sutures are generally Aoanthoceratld with shallow elements which are not much indented. Remarks : The present genus Is very much similar in general appearance and ornamentation to Calycoceras Hyatt, but is distinguished by multiplication of ribs at the inner ventro lateral tubercles, bullate outer ventro-lateral tubercles, and - 130 - a concave venter in the later growth stages of the shell. The last feature i.e . a concave venter, is characteristically found also in Mantelliceras Hyatt and in Sharpeiceras Hyatt. But it can easily be distinguished from them by presence of siphonal tubercles on the earlier whorls. The multiplication of ribs at the Inner ventrolateral tubercles is shown also by Euomphaloceras Spath but can easily be distinguished from it by absence of constrictions and a concave venter on the later whorls in Colerooniceras gen, nov. In Euamphaloceras Spath on the later whorls, the venter tends to become flat and slightly concave because of the fusion of inner and outer ventrolateral tubercles; more over in Euomphaloceras the maximum width of cross section is on the ventrolateral horns while^ in the present genus it is on the umbilical tubercles; and thus more like Calycoceras Hyatt. The early disappearance of siphonal tubercles is also a feature similar to Calycoceras Hyatt and Acanthoceras Neumayr. The multiplication of ribs at the inner ventrolateral tubercles has been taken as a criterion for including Acanthoceras aberrans Kossmat in Enomphaloceras Hyatt by Matsumoto e^ aj^. (l969) and on the absence of same criterion Acanthoceras^ batbyomphalum Kossmat has been assigned by them to Calycoceras Hyatt. Thus out present genus seems to be in between the two genera e .g . Calycoceras and Euomphaloceras. The material available for study at present and the strati- - 131 - graphic Information is not clear enough, however, to enable us to put the present genus in a phylogenetic sequence. It Is felt, all the same, that the present genus probably represents an off-shoot from the parent stock of Calvcoceraa which did not meet favourable conditions of development and as the species representing this genus is not yet known to occur in other countries it may represent a local development. Colerooniceras coleroonensis (Stoliczka) PI. XXIII, Figs. 1, 2 1865 Ammonites coleroonensis Stoliczka : Stoliczka, p. 71, pi. 37, figs. 4-6 1897 Acanthoceras colerunense (Stoliczka) : Kossmat, p. 2C, pi. 5, fig. 2 non 1972 Newboldiceras (Newboldiceras) coleroonense (Stoliczka) : Thomel, p. 105, pi. 35, figs. 3-4 Material : One specimen Plesiotype Kn 2 Dimensions t Diameter ef shell : 73.0 mm (l) Breadth of vyhorl section ; 36.0 mm (0.49) Height of whorl section : 29.0 mm (0.39) Umbilical diameter : 24.0 mm (0.34) Breadth of whorl section at i whorl : 28.0 mm (0.38) Height of whorl section at i whorl ; 20.0 min (0.30) B/H = 1.24 B/H at i whorl = 1.40 - 132 - Remarks : Typical characters of the genus as enumerated in generic diagnosis make the present material placeable in AmiBonltes coleroonensis Stoliczka now assigned to a new genus Colerooniceras gen. nov. Thomel (l972) has included Ammonites coleroonensls Stoliczka in Newboldiceras (Newboldiceras) Thomel, but the present author feels that Thomel's material does not belong to this species as it does not show Imllate outer ventro lateral tubercles and a concave venter in later stages of growth*^ his material does not show bifurcation of ribs at the ventrolateral tubercles and the rate of growth also {■n seems to be more rapid than|ooleroonen3is Stoliczka; the cross section is almost square in his material as against a depressed cross section of coleroonensis Stoliczka; the pattern of ribbing also Is different. It is more involute. It may be better included in Calycoceras newboldi. Occurrence : Brownish yellow sandy limestone of lower Calycoceras choffati zone near Kunnam. Subfamily ; Metoicooeratinae Hyatt, 1903 Genus ; Utaturlceras Wright, 1956 This genus has an interesting and somewhat complicated history. The type species of this genus Ammonites vicinalis Stoliczka was described by Stoliczka from the Utatur group of - 133 - Upper Cretaceous of South India. Stoliczka (1865) Illustrated his description by several figures representing variations in this species, and made a remark that It resembled ^Ammonites gaxbii Sharpe (1853) from the Cenomanian of England bnt detailed comparisons were not possible as Sharpe's descriptions and illustrations were not good. Kossmat (1897) transferred this species to Aoanthoceras, Spath (l926) considered Acanthoc eras vicinale (Stoliczka) as a zonal index for the top of the Cenomanian, and ffright (1957) and Collignon (l959) concurred with him. Wright (l956), however, erected a new genus Utaturiceras naming Ammonites viclnalis Stoliczka as its type and placing it in the subfamily Metoicoceratinae, Apparently Casey (i960) on the basis of Stoliczka’s remark and a further study of the English material regarded this species as a synonyn of Mante 11 Iccrasjirelated to the saxbli group. Matauraoto £t_ a]^. (1966) revised this species and pointed out differences in sutures of Utaturiceras vicinale (Stoliczka) and Mantellieeras and later in 1969 Matsumoto (p. 291) suggested a new subfamily for Utaturiceras Wright naming it Utaturiceratinae Kennedy and Hancock (1971), however, have disagreed with Matsumoto and considered it an unfortunate (p. 445) assessment. They are of the opinion that Utaturiceras vicinale (Stoliczka) should be placed In Mantelllceras as an extreme variant of saxbli group and thus agree with Casey (i960). - 134 - Our present collection has yielded only a small number of specimens which are identifiable with Stoliczka’s Ammonites v icin alis. This material comes from the Calycoceras choffati zone which considering also other associated forms 1b an elevated horizon in the Cenomanian. In view of such an occurrence and the number of specimens available for study being too few to decide such an Involved situation it is preferred to follow Wright (1956) for the present and take this material as belonging to Utaturiceras vicinale (Stoliczka) and place it in the subfamily Metoicoceratinae. While comparing the present material the author had an opportunity to study Stoliczka's type material at the G.S.I. Museum. Stoliczka’s type G.S.I. No. 176 (Stoliczka,1865, pi. XLIV, fig, 2) is a small form very much similar to Mantellicerao in ornament but has a siphonal ridge on the inner whorls which disappears very soon. There are medio-lateral tubercles on some ribs which make it similar to Mantelliceras. G .S .I . type No. 183 and 184 show development of Cheverons due to fusion of the inner and outer ventrolateral tubercles on the venter of the last l/4th part of the outer whorls; this m ^e s the author believe that they should be identified as Protacanthoceras Spath. G.S.I. type numbers 187, 189 and 190 are typicBl Utaturiceras and they show siphonal tubercles which make the author believe that they are better placed in Utaturiceras Wright than Mantelliceras Hyatt as suggested by Casey (i960), Kennedy & Hancock (l9 7 l). - 135 - In the present work the generic diagnosis given by Wright (1957, p, L416) as "Typically compressed with flat ribs, early whorls with distinct umbilical Inner and outer ventrolateral and slphonal tubercles but Inner ventrolateral and slphonal ones may weaken on outer whorls . . . ” Is accepted. There are some specimens with us which are more depressed In cross section and show characters Intermediate between Eucalycoceras barpax and Utaturiceras vlclnale. As the material at our disposal is only a lew specimens it is preferred not to comment on the ancestry of Utaturiceras vlclnale (Stollczka) till more convincing material becomes available . Utaturiceras vlclnale (stollczka) PI. XXIII, Figs. 3, 4 1865 -Aannonltes vlcinalls Stollczka : Stollczka, p. 84, pi. XLIV, parts only 1897 Ac ant hoceras vlclnale (Stollczka) : Kossnat, p. 25 Material : Three specimens, Pleslotype Od 11 Dimensions ; Diameter of shell : 80.0 mm (l) Breadth of whorl section: 26.0 mm (0,32) approx. Height of whorl section ; 44.5 mra (0,55) Umbllloal diameter ; 21.0 mm (0.26) Breadth of whorl section at whorl : 17.5 mm (0.2l) Height of whorl section at i whorl : 24.5 mm (0.30) B/H = 0.58 B/H at i whorl = 0.71 - 136 - Remarks : Shell small, compressed, involute; umbilicus moderately deep with steep walls; cross section tabulate with a flat narrow venter, appearing concave due to raised outer ventrolateral tubercles on outer whorls; aides slightly convex; maximum width of cross section at umbilical tubercles; early growth stages ornamented with strong,long aid short ribs and tubercles; number of short intercalaries, varying, being usually one or two, but soine times absent; in ail seven rows of tubercles, bullate umbilical, clavate inner and outer ventrolateral and siphonal; siphonal and inner ventrolateral tubercles disappeari>^ very soon, umbilical and outer ventrolateral persisting; and sutures not well preserved but apparently simpler than those in Calycoceras newboldi with shallower elements, help in tn keeping it^Utaturiceras vicinale (Stoliczka) from the Utatur group near Odium. Our specimens, however, show slightly higher umbilical proportion and a little more compreesed cross section as compared with Stoliczka's originalo. The plesiotype is slightly damaged, hence the measurements are to a small extent approximate. Our material seems to be a queer mixture of E. harpax (Stoliczka), C. newboldi (Kossmat) and U. vicinale (stoliczka). Occurrence : Brownish sandy limestone of Calycoceras choffati zone near Odium. Distribution : This species is known to occur from Upper Cenomanian of England, Madagascar, France, etc. - 137 - Subfamily ; Mammltinae Hyatt, 1900 This subfamily Is Represented by two genera In the present collection, Mammites Laube & Bruder and Pseudoaspidoceras Hyatt, and are restricted to the upper most part of the Utatur group i.e. Mammites concillatum zone. The well accepted range for this subfamily is from Upper Cenomanian to, but mostly in basal Turonian. Genus ; Mammites Laube & Bruder, 1886 ? Mammites sp. nov. PI.XXIV, Figs. 3,4 Material : One specimen, Holotype Yel 139 Dimensions; Diameter of shell : 195.0 mm (l) Breadth of whorl section: 86.0 mm (0.44) Height of whorl section ; 75.0 mm (0.38) Umbilical diameter : 50.0 mm (0.25) Breadth of whorl section at i whorl : 67,0 mm (0,33) Height of whorl section at i whorl : 60,0 mm (0,30) B/H =1.14 B/H at i whorl =1,11 Description : Shell large moderately Involute, with whorl section dipressed, polygonal with convex sides and a narrow concave venter; umbilicus deep with steep walls. It is ornamented with ribs and 8 rows of tubercles, umbilical, lateral, inner and outer ventrolateral; all the - 138 - tubercles show a tendency to grow stronger as the shell grows. The present specimen is asymmetric in ornament. The outer ventrolateral tubercles are disimilar, those on one side being strongly clavate and feeble while those on the other somewhat conical and strong. Umbilical tubercles placed on bulloid base are conical on top and the laterals conical. The ribs are rectiradiate in earlier whorls but become sinuous and stronger in the later. They arise in twos from the umbilical tubercles. Suture is like Mammites. Remarks : The present specimen is provisionally placed in Mammite s as it shows some characters similar to it, such as eight rows of tubercles and strong ribs; the nodose development of ventrolateral tubercles on the later parts of the shell is, however, a character like that of Mammites nodosoides (Schlotheim) from Lower Turonian of Gernftny. Eight rows of tubercles are seen also in Mantelliceras. but as the present material comes from a much higher horizon i.e. Mammites conciliatum zone of Upper Cenomanian to Lower Turonian, it ispreferred not to identify it as a species of Mantelliceras. When more material becomes available it may be possible to demonstrate that the present species belongs to probably a new genus. Occurrence 2 Brown clayey limestone from Mammites conciliatum zone at 3 Km from Illuppagoody to Kolkainattam. - 139 - Mammltes conclllatum (Stollczka) PI. XXIV, Figs. 1, 2 1865 -Ammonites conoiliatus Stojlczka : Stollczka, p, pi. 50, fig. 4 1897 Apanthoceras oonclliatum (Stoliczka) ; Kossmat, p. 22 1965 Pseudoaspldoceras conolliatum (Stoliczka) : Collignon, p.34, pi. 390, fig. 1666 1968 Manunites oonciliatum (Stoliczka) : Sastry, Rao & Mamgain, pi. 3, figs. 3,4 Material : Several fragments, Plesiotype Kn 50 Remarks ! The present material is id® tified as Mammites oonciliatum (Stoliczka) as it has a moderately evolute shell which is tumid with a trapezoidal cross section widest at umbilical tubercles. It has tubercles dominating over the ribs. The umbilical tubercles are spinose and ventrolateral tubercles are large while the ventral tubercles are placed in two rows giving rise to a concave venter. The ribs are both long and short, very faint almost undecipherable on sides and give rise to larger number of ventrolateral and ventral tubercles as compared to the umbilical tubercles. The sutures are not well preserved but from whatever is preserved it appears that there is a massive bifid first lateral saddle and a very broad first lateral lobe. Occurrence : Brownish yellow sandy limestone near Kunnam from the Mammites conclllatum zone.. This species is not very common. - 140 - Distribution : Outside South Indian basin this species is known to occur in Lower Turonian of Madagascar. Genus ; Pseudoaspidoceras Hyatt, 1903 This gai us is represented in the present collection by two species. One is the type species of the genus Pseudoaspidoceras Hyatt and another which appears to be new. The well accepted ancestry of Pseudoaspidoceras is through Mammites. Though the present collection is poor in number, all stages of growth are well represented. The shell is characterised by presence of constrictions and bifurcation of ribs at the ventrolateral shoulders, especially in Middle growth stages of the shell. These make it closely relatable to Euomphaloceras. As a matter of fact suture in the species described bare as new is very much like that of Mortoniceratid type and has a faint siphonal keel on the early stages of shell growth; possibly this feature combined with the pattern of the suture will warrant placing this into another subfamily. But in the present work It is preferred to place it in subfamily Mamniitinae as it has many other characters common with it. All the material In the present collection assignable to this genus comes from Mamaites conciliatum zone. - 141 - Pseudoaspldoceras sp. PI.XXVI, Figs. 1, 2 Material ; Three specimens, Holotype Kn 100 Dimensions Diameter of shell 130.0 mm (l) Breadth of whorl section 57.0 mm (0.43) Height of whorl section 57.0 ram (0,43) Umbilical diameter 48.0 mm (0,33) B/H =1.0 Description : Shell is large, evolute, quadrate in whorl uiiWV) section sides flat, wi4*r rounded umbilical and ventro lateral shoulders; the maximum width of cross section is at umbilical tubercles; venter is broad, flat or even slightly concave between the outer ventrolateral tubercles^ siphonal region raised into a faint keel; umbilicus has ateep walls. Ornamented with ribs and tubercles, in six rows of tubercles, umbilical, inner and outer ventrolaterals. Umbilical and inner ventrolateral tubercles are conical; outer ventrolaterals are slightly clavate, on early whorls. All the tubercles are equally strong but at later stages the umbilical and outer ventrolaterals become weak, while the inner ora ventrolaterals become stronger. Rlbs|l,strong rounded, prorslradiate and separated by much wider interspaces. » \s Suture'’ as in Mortoniceras |wl th a massive bifid first lateral saddle and a narrow trlfid, first lateral lobe. - 142 - Remarks ; As the material at our disposal Is small in number and fragmentary naming of the present species is postponed till more material becomes available. This species, is closely related to Pseudoaspidoceras footeanum (Stoliczka) with which it is associated in the Upper Utatur group of South India, but ynerrH can be distinguished from it by a|squartj)icross section, stronger ribs and in general feebler ornament. Occurrence : Brown sandy limestone of Mammites conciliatum zone at near Kunnam. Pseudoaspidoceras footeanum (Stoliczka) PI. XXV, Figs. 1, 2 1865 Ammonites footeanus Stoliczka ; Stoliczka, p*101, p i . . 52, figs, 1 a, b, c 1897 Aoanthoceras footeanum (Stoliczka) : Kossmat, p. 127 1903 Pseudoaspidoceras footeanum (Stoliczka) : llyatt, p. 106 Material : Two complete stells and several fragments, Plesiotype lOi 150 Dimensions : Diameter of shell : 95,5 mm (l) Breadth of whorl section: 49.0 mm (0.5l) Height of whorl section : 40.0 mra (0,4l) Umbilical diameter : 34.0 mm (0.85) Breadth of whorl section at ^ whorl : 39,0 mra (0.40) Height of whorl section at i whorl ; 22.0 mm (0.20) B/H =1.1 b/H at i whorl = 1.7 - 143 - Remarks : Shell large evolute; growth of shell slow; umbilicus moderately deep, with steep walls; cross section quadrate, rounded and broader than high, with flat sides; umbilical and ventrolatexal shoulders well formed; ornamented with strong tubercles and weak ribs; six rows of tubercles umbilical, inner and outer ventrolaterals; inner ventrolaterals strongest with the bulloid outer ventrolaterals tending to disappear on late stages of growth; ribs faintly indicated between umbilical and inner ventrolateral tubercles;on early whorls; they are numerous, long and short, bifurcating on inner ventrolateral tubercles with anterior ribs in the pairs projected forward on venter; faint ventral constrictions, and suture pattern similar to that of Mammites conciliatum (Stoliczka) help in Identifying this material as Pseudoaspidooeras footeanum (stoliczka) from Upper Utatur group at near Odium. Occurrence : Brown sandy limestone from Mammites conciliatum zone at near Kunnam, Section I I I ; Family : Vascoceratidae Spath, 1925 Genus : Fagesia Pervinquiere, 1907 This genus is represented by only two species and that too by only one specimen each. It is rather rare in these deposits. This genus is represented by two species in Stoliczka»s collection from South Indian Cretaceous rocks viz. Pagesla superstes and Fagesia rudra of which Fagesia superstes - 144 - (Kossmat) is represented in our collection. This species has been chosen by Collignon (1964) as a zonal index of the Lower Turonian of Madagascar. Fagesia sp PI. XXV, Figs. 3, 4 Material : One juvenile specimen, Holotype Kn 215 Dimensions : Diameter of shell : 58,0 ram (l) Breadth of whorl section: 3 7 »0 nm (0.63) Height of whorl section : 24.0 mm (o.4l) Umbilical diameter : 20,0 mm (0.34) B/H = 1.54 Description : The present solitary specimen is small and septate, depressed, evolute with a broad venter which is rounded and umbilicus deep with steep walls; the whorl section is somewhat kidney-shaped, it is ornamented with strong ribs and tubercles, in all four ix)»s of tubercles umbilical and ventrolateral; the ribs bifurcate at umbilical tubercles, are strong, separated by wider interspaces and stop at the ventro lateral tubercles, all the tubercles tend to become blunt as the shell grosvs. Sutures simple with a massive not much divided first lateral saddle, a shallow wide first lateral lobe, the second lateral saddle entire, the second lateral lobe reaching the umbilical seam; on the whole sutural elements are not much divided - 145 - Remarks : As the present material consists of one specimen, which is septate and shows a broad rounded venter, depressed whorl section, blunt umbilical tubercles, aid strong ribs. It is provisionally placed in Fagesia, and vrhen more material becomes available it may become possible to show that it is a new species . Occurrence : Brown sandy limestone of Mammites conciliatum zone near Kunnam. Fagesla superstes (Kossmat) PI. XXVII, Figs. 1, 2 1897 Olcostephanus superstes Kossmat : Kossmat, p. 26, pi. 6, figs. la-c 1907 Fagesia superstes (Kossmat) : Pervinquiere, p. 332, pi. 20, figs, 3^,b, 4 and A, text fig. 122 Material : One specimen, Pleslotype Kn 230 Dimaisions; Diameter of shell : 96,0 mm (l) Breadth of whorl section:92.3 mm (0.96) Height of whorl section: 38,0 mm (0,39) Umbilical diameter ; 29.0 mm (0.30) b/ h = 2,42 Remarks : Shell globular, cedicone; moderately evolute, whorl section depressed,kidney shaped; broad rounded venter; - 146 - umbilicus deep, with steep sloping walls; ornamented yjlth 14 blunt umbilical tubercles and faint ribs; ribs originating in twos or threes, from umbilical tubercles; sutures with shallow siphonal lobe, tall well indented lateral saddles, first lateral lobe bifid, aid as broad as the first lateral saddle, the third lateral lobe reachinjr the umbilical seam, make this material placeable In Fagesla superstes (Kossmat). Occurrence : Brown sandy limestone of Mammitea conciliatum zone Bear Kunnani. It is a rare species. Pistribution : This species is known from Turonian of Madagascar outside the South Indian Basin. Table showing distribution of Acanthoceran ammonolds in the Upper Cretaceous of South India Sr. Mortoniceras (M.): Mantelliceras ;Acanthoceras Calycooeraa : Maamites : Loner Trichinopoly Name of the species No. inflatum range : tuberculatum trhotomagense ohof fati : oonciliatum : groiip with Romanic eras & zone :assemblage zone rasseirblage zone acme zone ; assemblage zone : Kanabioeras 1. Mortoniceras (Pelradoceras) indicum sp.nov. X 2. Mortoniceras (Mortoniceras) Inflatum (Sow.) X 3. M. (M. ) rostratum (Sowerby) X 4.?M. (?M.) deshpandei sp. nov. 5. M. (Purnovarites) ? perinflatum Spath X 6. M. (D.) subquadratum Spath X 7. M. (D.) sp. indet X 8. Prohysteroceras (Goodhallites) stoliczkai X sp. nov. 9. Mantelliceras tuberculatum (Mantell) X 10. M. sp. cf. M. saxbii (Sharpe} X 11. M, sp. aff. M. mantelli (Sowerby) X 12. Calycoceras lativentralis sp. nov. X X 13. Calycoceras pseudoporthaultl sp, nov. X 14. Calycoceras tapaswii sp. nov. X X 15. Calycoceras pseudocoulonl sp. nov. X 16. Calycoccras shatrii sp. nov. X X 17. Calycoceras metmgaini sp, nov. X X 18. Calycoceras sp. indet X 19. Calycoceras naviculare (Mantell) 20. Calycoceras choffati (Kossmat) X X 21. Calycoceras planicostata (Kossmat) X X X X 22. Calycoceras spinosum (Kossmat) X X X X X 23. Calycoceras newboldi (Kossmat) X X X X X 24. Calycoceras gentonl (Brongniart) X 25. Calycoceras stoliczkai Collignon r\ ry ______i______Z’ T/’^ — n \ TABLE IV (continued) Sr. ;Mortoniceras(M .); Mantelllceras : Acanthoceres : Calyooceras : Mammites Lower Trichinopoly group No. Name of the Species : In f1 atum range ; tuberculatum : rhotomagense : cfaoffatl ; conclllatum with ^maniceras and : zone :assemblage zone: assemblage zone : acme zone :assemblage zone Kanablceras 27, Calycoceras paucinodatum (Crick) X X 28, Eucalycoceras harpax (Stoliczka ) X X 29, E. pentagonum (Jukes-Browne) X X 30, E, collignoni (Fabre) X 31, E, gothicum (Kossmat) X X 32, Acanthoceras matsumotol sp. nov. X 33, A, intermediatum sp. nov, X 34, A.rhhtomagense var, sussexiense (Mantell) X 35, A, rhotomagense var. confusum (Gueranger) X 36, A, sanctorum Mataumoto X 37, A. hunteri Kossmat X 38, Euomphaloceras cunnlngtont (Sharpe) X 39, E, merldionale (Stoliczka) X 40, E«aberrans (Kossmat) X 41, Kanablce ras septemseriatum (Cragin) 42, Romanlceras medlicottlanum (Stoliczka) 43, R. devarlanum (d'Orbigny) X 44, R. oldhami sp. nov, X 45, Yubariceras ornatissifflum (Stoliczka) X 46, Coleroonlceras coleroonensis(stoliczka) X 47, Utaturlceras viclnale(Stoliczka) X 48, ? Mammites sp, nov, X 49, Mamiiiites conciliatum (Stoliczka) X 50, Pseudoaspldoceras sp. X X 51, P, footeanum (Stoliczka) X 52, Fagesla sp, X 53, Fagesla superstes (Kossmat) PLATE I Mortonlceras (Pelradoceras) indlcum sp. nov. p. 20 Fig, 1. Lateral view of the Holotype Ut l/70 x 0.5 Fig. 3. Ventral view of the Holotype Ut 1/70 x 0.5 Mortoniceras (Mortonlceras) inflatum (Sowerby) p. 22 Fig. 2. Lateral view of the Plesiotype Ut 44/70 x 1 Fig, 4, Apertural view of the Plesiotype Ut 44/70 x 1 PLATE I PLATE I I ? Mortoniceras (? Mortonlceraa) deshpandel sp. nov, p. 25 Fig. 1. Ventral view of the Holotype Kn 92/70 x 1 Fig. 2. Lateral view of the Holotype Kn 92/70 x 1 Mortoniceras (Mortoniceras) rostratum (Sowerby) p. 23 Fig, 3. Lateral view of Ut 68/70 x 0.5 Fig. 4. Ventral view of Ut 68/70 x 0.5 PLATE n PLATE I I I Mortonloeras (Purnovarltes) ? perlnflatum Spath p. 28 Fig, 1. Ventral view of the Plealotype Ut 30/70 x 1 Fig. 2. Lateral view of the Pleslotype Ut 30/70 x 1 Mortoniceras (Pumovarltes) subquadratum Spath p, 30 Fig, 3. Lateral view of the Leototype Ut 38/70 x 1 Fig. 4. Apertural view of the Leototype Ut 38/70 x 1 PLATE m PLATE IV Mantelllceras sp, cf. M. saxbii (Sharpe) p. 43 Fig. 1. Lateral view of the nolo type Kn 115/72 x 1 Prohysteroceras (Goodhallites) stollczkat sp. nov. p. 34 Fig. 2. Ventral view of the Ilolotype TTt 45/70 x 0.5 Mantelliceras tuberculatum (Mantell) p. 41 Fig. 3. Lateral view of the Plesiotype Od 6/70 x 0.5 Mortoniceras (Purnovarites) sp. indet p. 3 2 Fig. 4. Lateral view of Ut 33/70 x 1 PLATE IV PLATE V Calycoceras latlventralis sp. nov. p. 50 Fig. 1. Lateral view of the Ho lotype Ut 31/70 x 1 Fig, 2. Apertural view of the Hole type Ut 31/70 x 1 Manteniceras sp. aff. Mantelliceras mantelli (Sowerby) p. 46 Fig. 3 . Lateral view of the Holotype Ut 70/70 x 0.5 Calycoceras pseudoporthaulti sp. nov. p. 53 Fig, 4. Lateral view of the Holotype Kn 139/72 x 0.5 PLATE V 4 A ' ■'v PLATE VI Calycoceras tapaswll sp, nov. p. 55 Fig. 1. Apertural view of the Ilolotype Kn l/l5 x 1 Fig. 2. Lateral view of the Holotype lui l/l5 x 1 Calycoceras pseudocouloni sp, nov. p. 59 Fig. 3. Lateral view of the Holotype l/l7 x 1 Fig. 4. Apertural view of the Holotype l/l7 x 1 PLATE VI pla te VII Calycoceras mamgaini sp. nov. p. 64 Fig, 1. Ventral view of the Holotype Kn 188/72 x 1 Fig, 2. Lateral view of the Holotype Kn 188/72 x 1 Calycooeras sastrii dp. nov. p. 61 Fig, 3. Ventral view of the Holotype Kn 11 x 0.75 Fig. 4, Lateral view of the Holotype Kn 11 x 0,75 PLATE VII PLATE V I II Calycoceras sp, Indet. P. 68 Fig. 1. Lateral view of the Holotype Kn I / I 6 x 1 Fig. 2. Apertural view of the Holotype Fn I / I 6 x 1 Calycoceras choffatl (Kossmat) p. 73 Fig. 3. lateral view of the Pleslotype Kn 10a x 1 Pig. 4 . Apertural view of the Pleslotype ICn 10a x 1 PLATE Vin 4 PLATE IX Calyooceras naviculare (Mantell) P. 70 Fig. 1. Lateral view of the Plesiotype Kn 4 x 1 Fig. 4. Apertural view of the Plesiotype Kn 4 x 1 Calyooceras planicostata (Kossmat'! P. 75 Fig. 2. Apertural view of the Plesiotype Od 31 x 1 Fig. 3. Lateral view of the Plesiotype Od 31 x 1 PLATE IX PLATE X Calycoceras gentonl (Brongniart) p. 80 Fig. 1. Apertural view of the Pleslotype Od 107/70 x 1 Calycoceras spinosum (Kossniat) p. 76 Fig. 2. Lateral view of the PIesiotype Kn 17 x 0.5 Fig. 3. Ventral view of the Plesiotype Kn 17 x 0.5 Calycoceras stoliczkai Collignon p. 82 Fig. 4. Lateral view of the Pleslotype Od 156/70 x 1 Fig. 6. Apertural view of the Plesiotype Od 156/70 x 1 Calycoceras bathyomphalum (Kossmat) p. 84 Fig. 5. Apertural view of the Pleslotype Od 15 x 1 PLATE X PLATE XI Calycoceras newboldi (Kossmat) p. 79 Fig, 1. Apertural view of the Plesiotype Od 260/70 x 1 Fig. 2. Lateral view of the Plesiotype Od 260/70 x 1 PLATE XI PLATE XII Eucalycoceras gothicum (Kossmat) p. 95 Fig, 1. Ventral view of the Pleslotype Kn 5 X 1 Fig. 5. Lateral view of the Plesiotype Kn 5 X 1 Eucalycoceras harpax (Stoliczka) p. 88 Fig, 2, Ventral view of the Plesiotype ICn 6 X 1 Fig. 4. Lateral view of the Plesiotype ICn 6 X 1 Eucalycoceras pentag^onum (Jukes-Browne) p. 92 Fig. 3. Lateral view of the Plesiotype Od 74 X 0.5 PLATE XII PLATE X I I I Calycoceras paucinodatuBi (Crlck) p. 85 Fig. 1. Ventral view of the Plesiotype Ut 32/70 x 1 Fig. 4. Lateral view of the Plesiotype Ut 32/70 x 1 Calycoceras gentonl (Brongniart) p. 80 Fig. 2. Lateral view of the Plesiotype Od 107/70 x 1 Acanthoceras Intermediatmn sp. nov, p. 100 Fig. 3. Lateral view of the Holotype Od 20/70 x 0.5 Acanthoceras sanctorum Matsumoto p. 106 Fig. 5. Lateral view of the Plesiotype Od 3 x 0.5 p l a t e XIII PLATE XIV Eucalycoceras collignoni (Fabre) p. 93 Fig. 1, Lateral view of the Plesiotype Sr 8/70 x 1 Fig, 2. Ventral view of the Plesiotype Sr 8/70 x 1 PLATE XIV PLATE XV Acanthoceras matsumotol sp, nov. p. 98 Fig. 1. Lateral view of the HolotypeOd 5/70 x 0.75 Fig. 2. Apertural view of the HolotypeOd 5/70 x 0,75 PLATE XV PLATE XVII Acanthoceras rhotomag,ense var. sussexiense p. 103 (Mantell) Fig. 1. Lateral view of the Plesiotype Od 13/70 x 0.75 Fig, 2. Apertural view of the Plesiotype Od 13/70 x 0.75 PLATE XVI PLATE XVII Acanthoceras rhotoma^ense var. sussexiense p. 103 (Mantell) Fig, 1. Lateral view of the Plesiotype Od 13/70 x 0.75 Fig, 2. Apertural view of the Plesiotype Od 13/70 x 0.75 PLATE XVII PLATE XVIII Aoant hoceras hunt eri Kossmat p. 108 Fig, 1, Lateral view of the Plesiotype Od 63 x 0,6 Eucalycoceras abergans (Kossmat) p. 114 Fig. 2. Ventral view of the Plesiotype Kn 186/72 x 2 Fig, 3. Lateral view of the Plesiotype Kn 186/72 x 2 PLATE XVIII PLATE XIX Euomphaloceras cunningtoni (Sharpe) p .110 Fig. 1. Lateral view of the Flesiotype Od 172/70 x 1 Fig. 2. Ventral view of the Pie8iotype Od 172/70 x 1 PLATE XIX PLATE XX Euomphaloceras meridlonale (Stoliczka) p. 112 Fig, 1. Lateral view of the PlesiotypeOd 6/70 x 1 Fig, 2, Apertural view of the PlesiotypeOd 0/70 x 1 PLATE XX PLATE XXI Romaniceras oldhaml ap. nov. p. 124 Fig. 1, Lateral view of the Holotype Sd 94/70 x 0.5 Fig, 2, Apertural view of the nolotype Sd 94/70 x 0.5 Kanablceras septemseriatum (Cragin) F. 117 Fig. 3, Ventral view of the Plesiotype Sd 90/70 x 2 Romaniceras medlicottlanuin (Stoliczka) p. 121 Fig, 4. Ventral view of the Plesiotype Yel 31 x 0.4 Fig. 5. Lateral view of the Plesiotype Yel 31 x 0,4 PLATE XXI PLATE XXII Yubarlceras ornatlsslnum (Stoliczka) p. 127 Fig, 1. Lateral view of the Pleslotype ICn 96/70 x 1 Fig. 4 , Ventral view of tbe Pleslotype Kn 96/70 x 1 Romaniceras devarianum (d ’Orblgny) p. 123 Fig. 2. Ventral view of the Pleslotype Sd 42/70 x 1 Fig. 3. Lateral view of the Pleslotype Sd 42/70 x 1 PLATE XXIII Coleroonlceras ooleroonensls (Stollczka) p. 131 Fig, 1, Lateral view of the Plesiotype Kn 2 x 1 Fig, 2. Apertural view of the Plesiotype Kn 2 x 1 Utaturiceras viclnale (Stoliczka) p. 135 Fig. 3, Lateral view of the Plesiotype Od 11 x 1 Fig. 4. Apertural view of the Plesiotype Od 11 x 1 PLATE XXIJI PLATE XXIV Mammltes conclliatum (Stoliozka) p. 139 Fig, 1. Apertural view of the Piesiotype Kn 50 x 0.5 Fig. 2, Lateral view of the Plealotype Kn 50 x 0.5 ? Mammltes sp. nov. p, 137 Fig, 3, Lateral view of the Holotype Yel 139 x 0.5 Fig. 4. Ventral view of the Holotype Yel 139 x 0.5 PLATE XXIV PLATE XXV Pseudoaspidoceras footeanum (Stoliczka) p. 142 Fig, 1, Apertural view of the Pleslotype Kn 150 x 1 Fig. 2. Lateral view of the Plesiotype Kn 150 x 1 Fagesia sp. p. 144 Fig. 3. Apertural view of the Kolotype Kn 215 x 1 Fig. 4. Lateral view of the Holotype Kn 215 x 1 PLATE XXV PLATE XXVI Pseudoaspldioeras sp, p. 141 Fig. 1, Apertural view of the Holotype Kn 100 x 1 Fig. 2. Lateral view of the Holotype Kn 100 x 1 PLATE XXVI PLATE XXVII Fagesla superstes (Kossmat) p. 145 Fig, 1, Lateral view of the Pleslotype Kn 230 x 1 Fig. 2. Apertural view of the Pleslotype Kn 230 x 1 p l a t e XXVII