Type species: Ampullaria depressa Lamarck, 1804, Grignon, Lutetian.

Description.—Worldwide, this genus consists of 42 species in the Cainozoic, of which 41 occur in the Palaeogene (SOM 1). 14 of the 34 species observed under UV light reveal a simple and unsophisticated residual colour pattern consisting of fluorescent straight spiral stripes or a diffuse area (SOM 2). However, on the basis of shell morphology, we include in this genus three species previously attributed to Crommium, Ampullina intermedia (Deshayes, 1832), Ampullina lignitara (Deshayes, 1864), and Ampullina merciniensis (Deshayes, 1864). They display fluorescent patches or segments, sometimes superimposed on broad spiral stripes.

Stratigraphic and geographic range.—Middle Eocene, Lutetian—Bartonian (PB, Loire-Atlantique).

Colour pattern description.—The pattern consists of three levels of residual colouration. The background is heterogeneous with a fluorescent spiral stripe located just below the subsutural step (Fig. 2A₁). The apex is paler. The diffuse stripe varies in breadth and the whorl is sometimes almost entirely fluorescent (excepting the subsutural step and the base). In the latter case, the stripe may have a different colour (more orange) and is still distinguishable. An additional thin median stripe is seen (Fig. 2A₂) in several specimens.

Stratigraphic and geographic range.—Early Eocene, Ypresian (Cuisian)—Middle Eocene, Bartonian and Priabonian (PB, Cotentin, HB).

Colour pattern description.—The residual pattern is variable and consists of three levels of residual colouration. The background is heterogeneous with one (Fig. 2B, C₁) or two fluorescent spiral stripes and the apex is pale (Fig. 2C₁). The transition between the two levels of residual colouration of the background is diffuse. There are usually two fluorescent stripes: a broad one on the adapical part and a thinner one on the adbasal part (Fig. 2C₂). The width of the adapical stripe varies among specimens. Sometimes there are two thin adbasal stripes very close to each other instead of one. The adbasal stripe is sometimes absent and several specimens have an additional thin subsutural fluorescent stripe. Some specimens display a single broad stripe spreading on the major part of the whorl. Although the whorl could be almost entirely fluorescent (excepting the subsutural step and the base), the adapical stripe is sometimes in a different colour (more orange) and remains distinguishable.

Comments on the residual colour pattern of A. depressa depressa and A. parisiensis.—Several hypotheses can be advanced to explain the occurrence of two different colours in the background fluorescence: (i) the chemical nature of the incorporated pigments; (ii) the concentration of the incorporated pigments; (iii) the modalities of incorporation. The first two hypotheses appear plausible. Previous studies, chromatographic (Comfort 1949a–c, 1950, 1951; Nicholas and Comfort 1949) and spectrometric (Hedegaard et al. 2006) analyses, have indeed revealed differences in the nature of the substances involved in the pigmentation of gastropod shells. Moreover Hedegaard et al. (2006) also indicated that there is no simple relationship between pigment, colour and taxa: different colours within a single taxon may be due to different pigments or different saturations of colour can be generated by different concentrations of the same pigment.

Stratigraphic and geographic range.—Middle Eocene, Lutetian (PB, Cotentin).

Colour pattern description.—The shells show three levels of residual colouration. The background is heterogeneous with a dark subsutural step and a wide fluorescent area covering the major part of the whorl (Fig. 2D₂). The apex is pale. The transition between the fluorescent area and the darker area of the background is mostly diffuse. The absence of fluorescence on the subsutural step induces a dark straight spiral “stripe” (Fig. 2D₁). The base of the whorl may be dark too. Sometimes, there are also slightly darker thin and diffuse spiral “stripes” on the last whorl due to a localized lack of fluorescence. These “stripes” are related to obsolete spiral “microlines” and their number and distribution are variable. The residual colour pattern is very similar to that of A. grossa (Deshayes, 1864) from the Lutetian—Bartonian of the Paris Basin (Fig. 2E).

Stratigraphic and geographic range.—Late Palaeocene, Thanetian (PB).

Colour pattern description.—The pattern consists of three levels of residual colouration: a heterogeneous background with three spiral fluorescent stripes (Fig. 2F) and a pale apex. The transition between the two levels of colouration is diffuse. The median stripe is slightly broader than the two others (Fig. 2F₁).

Stratigraphic and geographic range.—Late Palaeocene, Thanetian—Early Eocene, Ypresian (Cuisian) (PB).

Colour pattern description.—The pattern consists of three levels of residual colouration. The background is heterogeneous with three fluorescent spiral stripes (Fig. 2G, H) and the apex is pale. The transition between the two levels of residual colouration of the background is diffuse. These stripes are located on the shoulder and on the median and adbasal parts of the whorl. Their thickness is not homogeneous on the shell and varies among specimens (Fig. 2G, H₁).

Comments.—The figured shells (Fig. 2G, H) are from the Thanetian of Bachivillers (France, PB) from where this species' occurrence has never been listed. However their shell shape, oblong with slightly elevated and turreted spire and tabulate whorls, differs obviously from the sole previously known Thanetian species A. chenayensis (Fig. 2F) which is globose with a low spire and lacks tabulate whorls. We consider that our specimens display the characteristic morphology of the Cuisian species A. aizyensis and that they represent the oldest known occurrence of this species.

Stratigraphic and geographic range.—Early Oligocene, Rupelian (Stampian) (PB).

Colour pattern description.—The shells show two levels of residual colouration under UV light (apex absent). The background is dark and heterogeneous with three spiral fluorescent stripes (Fig. 2I). The transition between the two levels of colouration is diffuse. The stripes are located on the adapical part, median part and adbasal part of the whorl. Their width is almost equal in the youngest specimens, but the median one becomes broader in most adult specimens. Some young specimens display a fourth spiral stripe around the umbilicus on the base of the shell.

Stratigraphic and geographic range.—Middle Eocene, Lutetian—Bartonian (Italy).

Colour pattern description.—The pattern consists of two levels of residual colouration: a pale heterogeneous background with several dark spiral stripes. Sometimes, there is only a group of two or three thin stripes very close to each other, of a variable width (Fig. 2J), on the median part. There is sometimes an additional broad adapical stripe (Fig. K).

Comments.—The residual colours in this species are observable in natural light and are obviously different from those of the other species. This is the result of a different type of preservation of the colour pattern. It is also interesting to note that this pattern appears as the negative of the residual colour pattern on the other shells and that the dark elements in this species correspond to the fluorescent ones in UV light observations.

Stratigraphic and geographic range.—Early Eocene, Ypresian (Cuisian) (PB).

Colour pattern description.—The pattern consists of four levels of residual colouration. The background is heterogeneous with three spiral slightly fluorescent stripes, one on the adapical part, one on the median part and one on the adbasal parts of the whorl (Fig. 3A). The apex is pale and there are small fluorescent patches superimposed on the background (Fig. 3A–C). The transition between the levels of colouration of the background is diffuse. The background is homogeneously dark in some specimens (Fig. 3B–E). The small patches of varying size do not have a definite shape and their distribution is irregular (Fig. 3B). The coalescence of the patches sometimes produces fluorescent sinuous axial segments (Fig. 3D, E). This residual colour pattern is very similar to those of A. merciniensis (Deshayes, 1864) (Fig. 3F) from the Ypresian (Cuisian) of the Paris Basin and Ampullina lignitara (Deshayes, 1864) from the Ypresian (Sparnacian) of the Paris Basin and Hampshire Basin.

Comments.—Former authors (Cossmann 1888; Wrigley 1946; Gilbert 1963) considered the three species Ampullina intermedia (Deshayes, 1824), A. lignitara (Deshayes, 1864) and Ampullina merciniensis (Deshayes, 1824) as belonging to the genus Crommium. In the original description of the genus, Cossmann (1888) however stated, that the sheath is absent whereas it occurs in each of the three aforementioned species. Thus, A. intermedia, A. lignitara, and A. merciniensis are, here, no longer considered to belong to the genus Crommium. Furthermore, these species with closely related shells, display very similar residual patterns. Consequently, our personal opinion is that the discrimination of these three species is probably not justified.

Type species: Globularia sigaretina (Lamarck, 1804), Grignon, Lutetian.

Description.—This genus is here considered to comprise three subgenera (Globularia, Deshayesia, and Cernina) with 20 species (16 Palaeogene species, 3 Neogene and one extant; SOM 1). The taxa Globularia, Cernina, and Deshayesia have not always been regarded as congeneric (Wrigley 1946). Nevertheless, the very similar residual colour patterns of 11 of the 15 studied species (zigzagging axial fluorescent stripes; SOM 2; Fig. 4, 5) strengthens the initial impression based on the shell morphology (wide aperture with prosocline outer lip, low spire and expanded sheath delineated by a rim) that they are closely related (Cossmann and Peyrot 1919; Wenz 1941). Thus, thanks to the additional character, all these species are, here, no longer considered to belong to distinct genera but are placed within the genus Globularia (senior synonym).

Stratigraphic and geographic range.—Middle Eocene, Lutetian—Bartonian (PB, HB).

Colour pattern description.—The shells show four levels of residual colouration. The background is often dark and homogeneous (Fig. 4A, C), but it can be heterogeneous with slightly fluorescent broad spiral stripes (Fig. 4B). The apex is pale and there are fluorescent axial thin zigzagging stripes superimposed on the background (Fig. 4A, C). The transition between the two levels of residual colouration of the background is diffuse. Zigzags occur along the whole height of the stripes and have variable amplitude (Fig. 4A). The density of the zigzags varies with the specimens. One specimen shows an additional fluorescent spiral stripe (Fig. 4C) on the base of the shell. This residual colour pattern is very similar to that of Globularia (G.) berthelini (Cossmann, 1892) from the Lutetian of the Paris Basin (Fig. 4D–F).

Stratigraphic and geographic range.—Middle Eocene, Lutetian—Bartonian (PB, HB).

Colour pattern description.—The pattern consists of four levels of residual colouration. The background is heterogeneous with two broad slightly fluorescent diffuse spiral stripes on the adapical and adbasal parts of the whorl (Fig. 4I–L). The apex is pale and there are one (Fig. 4I–K) or two (Fig. 4G, H, L) fluorescent sharply delineated spiral stripes superimposed on the background. These two straight fluorescent spiral stripes, superimposed on the dark median “stripe” of the background, are located near its adbasal margin and on its adapical margin. They do not become diffuse through ontogenesis. The adapical one is absent in the shells showing only one stripe (Fig. 4I–K).

Stratigraphic and geographic range.—Late Palaeocene, Thanetian—Middle Eocene, Ypresian (Cuisian) (PB).

Colour pattern description.—This species shows three levels of residual colouration. The background is dark and homogeneous. The apex is pale and there are axial thin fluorescent zigzagging stripes (Fig. 4M). The axial thin stripes present a regular distribution. The zigzags occur along the whole height of the stripes and display variable amplitude. There is intraspecific variability in the number and density of the axial thin stripes. This residual colour pattern is very similar to those of Globularia (G.) splendida (Deshayes, 1864) from the Ypresian of the Paris Basin (Fig. 4N) and Globularia (G.) patuloides (Cossmann, 1902) from the Bartonian of the Paris Basin (Fig. 4O).

Stratigraphic and geographic range.—Late Oligocene, Chattian—Early Miocene, Aquitanian (AB).

Colour pattern description.—The shell displays only two levels of residual colouration (apex absent). The background is dark and homogeneous. There are numerous axial fluorescent thin zigzagging stripes (Fig. 5A). The zigzags occur along the whole height of the stripes and have variable amplitude. The thin stripes are not strictly parallel and connect to each other at several points. These connections produce the occurrence of large fluorescent “patches” (Fig. 5A₁, A₂).

Stratigraphic and geographic range.—Middle Eocene, Lutetian (PB).

Colour pattern description.—The colour pattern consists of three levels of residual colouration: a dark and homogeneous background, a pale apex and some thin fluorescent axial stripes forming zigzags (Fig. 5B₂, C). The axial thin stripes are not parallel and present an irregular distribution. The zigzags occur along the whole height of the stripes and display variable amplitude. There is intraspecific variability in the density of axial stripes (Fig. 5B₂, C₂).

Comments.—?Globularia pilula has been previously classified in the naticid genus Euspira. These shells strongly differ from the type species of the latter genus, Euspira glaucinoides (Sowerby, 1812) from the Ypresian of England, in many characters (moderately high and acuminate spire, sutural step, minute umbilicus with no sheath and narrow reflected columellar edge). Furthermore, the colour pattern differs from those of the fossil naticid shells by converging stripes and numerous zigzags with very variable amplitude as observed in the characteristic colour pattern of genus Globularia. Thus, this species is, here, excluded from Euspira and is placed within the family Ampullinidae, but only questionably placed in the genus Globularia, because of its lack of a sheath.

Stratigraphic and geographic range.—Recent (Philippines).

Colour pattern description.—The pattern consists of four levels of colouration. The background is heterogeneous with broad spiral brown stripes. There are four brown stripes on the last whorl (Fig. 5D₂, D₃, E₂): (i) one on the adapical part, (ii) one near the base, and (iii–iv) two stripes, slightly broader, on the median part. The apex is pale and there are white thin axial zigzagging stripes. The transition between the two levels of the background is diffuse. The axial zigzagging stripes are more or less parallel and present an irregular distribution on the shell. Some of these stop on the median part of the whorl (Fig. 5D₂, E₂). The amplitude of the zigzags varies. There is intraspecific variability in the number and density of the axial stripes.

Comment.—The brown (darker) stripes correspond to the fluorescent (paler) stripes revealed under UV light in the fossil shells and the white axial zigzagging stripes are here considered to correspond to the fluorescent zigzagging stripes.

Stratigraphic and geographic range.—Early Miocene, Aquitanian and Burdigalian—Middle Miocene, Langhian (AB, Italy).

Colour pattern description.—This species shows two levels of residual colouration (apex absent). The background is dark and homogeneous. There are thin axial fluorescent stripes. The thin axial stripes are very close to each other, but not parallel and form small zigzags (Fig. 5F₁, G). Their distribution on the shell is variable (Fig. 5G) and the zigzags display variable amplitude. The stripes sometimes branch in a dichotomous manner (Fig. 5F₂).

Stratigraphic and geographic range.—Early Miocene, Aquitanian (AB).

Colour pattern description.—These shells show two levels of residual colouration (apex absent): a dark and homogeneous background and opisthocline thin fluorescent stripes (Fig. 5H, I). These opisthocline stripes are very close to each other, parallel and present a regular distribution. Their thickness is constant on the shell and they are barely sinuous.

Comments.—All three specimens from Saint-Martin-d'Oney (France, AB) display the characteristic morphology of Globularia (Cernina) compressa but the coloured pattern differs by the presence of opisthoclines, barely sinuous, thin stripes instead of axial zigzagging stripes (Fig. 5F, G). In our view, these differences do not result from intraspecific variability and justify these shells as belonging to a species other than G. (C.) compressa.

Type species: Deshayesia parisiensis Raulin, 1844, Morigny, Rupelian (Stampian).

Stratigraphic and geographic range.—Early Oligocene, Rupelian (PB).

Colour pattern description.—The shells show three levels of residual colouration (apex absent). The background is heterogeneous with three broad spiral slightly fluorescent stripes and there are some axial and fluorescent thin zigzagging stripes. The spiral stripes are located (i) on the subsutural part, (ii) near the base, and (iii) on the median part. The transition between the two levels of colouration of the background is diffuse. The thin axial zigzagging stripes are superimposed on the background (Fig. 5J₁, J₃). The thin axial stripes connect each other in several points and their distribution on the shell is regular. The zigzags present variable amplitude.

Type species: Ampullaria willemeti Deshayes, 1825 (= A. acutum Lamarck, 1804), Courtagnon, Grignon, Lutetian.

Description.—The genus Crommium comprises 6 exclusively Palaeogene species (SOM 1). Of the 4 species (SOM 2) observed under UV light 2 display the same very simple morphology of the colour pattern with a fluorescent more or less wide area covering the adapical part (Fig. 6).

Stratigraphic and geographic range.—Middle Eocene, Lutetian—Bartonian (PB, HB)

Colour pattern description.—The shells show three levels of residual colouration. The background is heterogeneous with a fluorescent area covering the apical part of the whorl (Fig. 6A, B) (except a thin zone just below the suture). The apex is pale. The transition between the two levels of colouration of the background is diffuse. There is sometimes a second fluorescent diffuse area on the base of the shell. These fluorescent areas cover a smaller or larger part of the whorl. The largest specimens show an entirely fluorescent last whorl (except the subsutural part). The young specimens display three or four thin spiral fluorescent stripes: one on the shoulder, one on the base (but often lacking) and two on the median part of the whorl (Fig. 6C). The two median stripes fade with growth until they disappear. The adapical one and the basal one, when present, gradually spread on the whorl.

Stratigraphic and geographic range.—Middle Eocene, Lutetian (PB)

Colour pattern description.—This species exhibits three levels of residual colouration. The background is heterogeneous with a slightly fluorescent apical part (Fig. 6D). The transition between the two levels of the background is diffuse.

Type species: Amaurellina spirata Lamarck, 1804, Grignon, Lutetian.

Description.—Worldwide, this genus comprises 8 species in the Cainozoic (SOM 1). 5 of the 6 studied species (SOM 2) display the same simple organisation of residual colouration with one or several fluorescent spiral stripes on a darker background.

Stratigraphic and geographic range.—Middle Eocene, Lutetian (PB, Cotentin)

Colour pattern description.—This species shows three levels of residual colouration. The background is heterogeneous with an almost completely dark whorl except the slightly fluorescent shoulder that forms a spiral stripe (Fig. 7A–C). The apex is pale (Fig. 7A–C). The fluorescent stripe covering the subcarinate shoulder is straight and has a constant width (Fig. 7A₁, C). This stripe is sometimes also observable on the penultimate whorl (Fig. 7C). The transition between this stripe and the darker colouration of the whorl is diffuse. The base of the whorl can be slightly fluorescent too.

Stratigraphic and geographic range.—Early Eocene, Ypresian (Cuisian) (PB)

Colour pattern description.—The shells show two levels of residual colouration: a heterogeneous background with a slightly fluorescent area covering the major part of the shell (apex, spire, last whorl) except two dark “stripes”. The adapical one is on the median part of the whorl and is thinner than the other one located on the base of the shell (Fig. 7D, E). On a few well-preserved shells, some slightly fluorescent axial stripes are distinguishable (Fig. 7F). These axial stripes, especially distinguishable on the spire, are slightly prosocline.

Stratigraphic and geographic range.—Early Eocene, Ypresian (Cuisian) (PB).

Colour pattern description.—The residual pattern consists of three levels of residual colouration. The background is heterogeneous with thin fluorescent spiral stripes and the apex is pale. There are two straight stripes and the adapical one is sometimes distinguishable on the penultimate whorl (Fig. 7G₂, I). Both stripes have constant and similar width.

Stratigraphic and geographic range.—Early—Middle Eocene, Ypresian (Cuisian)—Lutetian (PB, HB).

Colour pattern description.—The residual pattern consists of three levels of residual colouration. The background is dark and homogeneous, the apex is pale and there are four straight fluorescent spiral stripes (Fig. 7J₁): one is located on the subsutural part of the whorl, one is on the base, circling the umbilicus, and two are on the median part. These stripes present a similar and constant width and are slightly thinner than the space between. The two adapical stripes are sometimes distinguishable on the penultimate whorl. This residual colour pattern is very similar to that of Amaurellina tuba (Deshayes, 1864) from the Lutetian of the Paris Basin (Fig. 7L).

Type species: Amaura guppyi Gabb, 1873, Dominican Republic, Miocene.

Description.—Among the 8 Cainozoic species in the genus Pachycrommium known worldwide (with one present in the Neogene; SOM 1), 7 have been examined (SOM 2). All the species reveal some fluorescent axial, or opisthocline for Pachycrommium acuminatum (Lamarck, 1804), stripes or segments on a darker background (Figs. 8, 9).

Stratigraphic and geographic range.—Early Eocene, Ypresian (Cuisian) (PB)

Colour pattern description.—The pattern consists of three levels of residual colouration. The background is dark and homogeneous, the apical whorls appear paler than the rest of the spire but are rarely preserved and there are some axial fluorescent stripes (Fig. 8A, B). The axial stripes, straight to sinuous and slightly prosocline (Fig. 8A₁, B₂), are only observable on the spire. The width of the stripes is equivalent to that of their interspaces and their distribution is regular. This residual colour pattern is very similar to those of Pachycrommium productum (Deshayes, 1864) from the Lutetian of the Paris Basin (Fig. 8C), Pachycrommium sp. from the Ypresian of the Paris Basin (Fig. 8D) and Pachycrommium hybridum (Lamarck, 1804) from the Bartonian (Auversian) of the Paris Basin.

Stratigraphic and geographic range.—Middle Eocene, Lutetian (PB, HB).

Colour pattern description.—The colour pattern consists of a dark and homogeneous background and broad axial slightly fluorescent stripes (Fig. 8E, F). These stripes appear straight on the spire but present saw-tooth edges. They actually form zigzags spreading over the whole height of the whorl. Their width is not constant (Fig. 8F).

Stratigraphic and geographic range.—Middle Eocene, Lutetian (PB).

Colour pattern description.—This species show three levels of residual colouration: a dark and homogeneous background, a pale apex and fluorescent rows of small axial coalescent segments. These fluorescent and thin segments very close to each other form small zigzags and are more or less elongated. Their width is not constant (Fig. 9B₂, F₂, G₂). The coalescence produces, on the subsutural step, broad triangular fluorescent patches. The segments are often opisthocline and the frequency of the zigzags varies among individuals (Fig. 9B₂, C, G₂, H₂).

Stratigraphic and geographic range.—Oligocene, Chattian— Miocene, Burdigalian (AB).

Colour pattern description.—The pattern consists of three levels of residual colouration. The background is dark and homogeneous, the apex is pale and there are broad axial fluorescent stripes (Fig. 9I, J, K₃). The stripes are broader than the interspaces and their width increases with growth (Fig. 9I₂). Their distribution is regular and they may be straight (Fig. 9I₁) or sinuous (Fig. 9J₁). Some specimens from Dax (Fig. 9J, K) display an additional level of colouration: some patches much darker than the background, more or less axially compressed, with irregular distribution and often coalescent (Fig. 9J₂, K).

Type species: Ampullaria ambulacrum Sowerby, 1822, Barton, Bartonian.

Description.—No residual colour pattern is observed under UV light.

Remarks.—This genus comprises 5 worldwide Cainozoic species (SOM 1). Two of the studied species of Ampullonatica, A. ambulacrum (Sowerby, 1822), and A. brongniarti (Deshayes, 1864) from the Bartonian of England and France (HB, PB; SOM 2), are characterised by an acuminate and moderately high spire turreted by a deeply canaliculated suture, a large and deep umbilicus with an undistinguishable sheath and a thin and narrow columellar edge. This shell morphology is similar to the shell morphology of the enigmatic taxon Amauropsina.

?Ampullonatica gouberti (Deshayes, 1864), described on the basis of a unique specimen from the Bartonian of France, displays unusual shell morphology (very strong shoulder, very low spire) and might be a teratological specimen of an already known species (e.g., Ampullina parisisiensis).

Type species: Ampullaria canaliculata Lamarck, 1804, Grignon, Lutetian.

Description.—The two Palaeogene species of this genus (SOM 1, 2) display various morphologies of the colour pattern varying from fluorescent patches more or less regularly positioned on a darker background to axial fluorescent segments formed by coalescence of these patches.

Remarks.—The morphology of the species of Amauropsina (elevated and acuminate spire, large umbilicus without sheath, narrow columellar edge somewhat reflected and, in the type species a narrowly canaliculated suture) is not representative of the Naticidae. This rather resembles the shell morphology of the ampullinid genus Ampullonatica (no residual pattern under UV light). However, the colour pattern of A. arenularia is similar to that revealed in Eocene naticids (Le Meur 2009) and that of A. canaliculata displays sparse small fluorescent patches, unknown from other naticids and even from other ampullinids. Interpretations of the systematic affinity of this genus derived from shell morphology and colour pattern data differ and so the genus Amauropsina remains an enigmatic taxon.

Stratigraphic and geographic range.—Middle Eocene, Lutetian—Bartonian (Auversian) (PB, HB).

Colour pattern description.—The pattern consists of three levels of residual colouration: a dark and homogeneous background, a pale apex and small fluorescent patches (Fig. 10A–C). The small patches are of variable size and shape and present an irregular distribution (Fig. 10B₁, C). There is intraspecific variability in the density and coalescence of the patches. The coalescence sometimes produces fluorescent sinuous axial segments (Fig. 10D).

Stratigraphic and geographic range.—Middle Eocene, Lutetian—Bartonian (PB, Loire-Atlantique).

Colour pattern description.—This species exhibits three levels of residual colouration. The background is dark and homogeneous. The apex is pale and there are three spiral rows of fluorescent patches. The patches are variable in shape and they are axially and spirally aligned (Fig. 10E). A specimen from Saffré (Loire-Atlantique) displays some sinuous axial segments (Fig. 10F). Depending on the part of the shell, there may be only axial elongated sinuous segments or alternating elongated and short straight segments (Fig. 10F₂). In the latter case the two types of segments are sometimes connected (Fig. 10F₃).