BULLETIN DE L’INSTITUT ROYAL DES SCIENCES NATURELLES DE BELGIQUE SCIENCES DE LA TERRE. 72: 111-134, 2002 BULLETIN VAN HET KONINKLIJK BELGISCH INSTITUUT VOOR NATUURWETENSCHAPPEN AARDWETENSCHAPPEN, 72: 111-134, 2002

Systematic revision of Palaeocene brackish water from Mons, Belgium, based on their early ontogenetic shells

by Thorsten KOWALKE

Kowalke, T.. 2002. - Systematic revision of Palaeocene brackish Introduction water Gastropoda from Mons, Belgium, based on their early ontoge­ netic shells. Bulletin de l'Institut royal des Sciences naturelles de Belgique, Sciences de la Terre, 72: 111-134, 4 pis., Bruxelles-Brussel, The Early Mid-Palaeocene sediments of Mons, Southeast March 31, 2002. - ISSN 0374-6291 Belgium, were brought to the attention of geologists, when the mining engineers F.L. Cornet and A. Briart recognised a section within a domestic well on the Gof- fint property in 1865. In 1874, the Geological Society of Abstract France initiated a second pit a few metres to the west on The systematic position of Early Mid-Palaeocene brackish water Gas­ the Coppée estate. These original sinkings were termi­ tropoda from the Dano-Montian of Mons, South-east Belgium, is nated at a depth of about 20 m, when the ground water revised. Representatives of the subclasses (with the floor was reached. In 1969 another boring was initiated new Monsneritina- , ), (with the new genus Monspotamides - , ) by the Belgian Geological Survey, located 10 m south of and Heterostropha are characterised with regard to their paleoecology. the Gofflnt pit. The sections - detailed descriptions of the Three different modes of early ontogenetic development are recognised stratigraphy and sketches of the locality were given by and paleoecological inferences are discussed. M a r l i è r e (1977) - commence with Dano-Montian de­ Key-words: Palaeocene, Belgium, brackish water Gastropoda, early posits (68.7 m thick in the 1969 boring) are then suc­ ontogenetic development, palaeoecology ceeded by a Landenian (Late Palaeocene) silty glauconi­ tic sand, which is overlaid by deposits. In the 1969 boring the Maastrichtian basement (“Craie de Spiennes” ) is also exposed. The Dano-Montian consists Résumé of more or less solid limestones with marly intercalations.

Les gastéropodes saumâtres d’âge Paléocène Moyen du Dano-Montien The upper part of the section (“Calcaire grossier de de Mons. Belgique, sont revus. Des représentants des sous-classes des Mons” ) is fossiliferous, containing assemblages of mar­ Neritimorpha, avec un nouveau genre Monsneritina (Neritoidea, Ner­ ine, brackish water and fluvial . itidae), des Caenogastropoda, avec un nouveau genre Monspotamides The well-preserved molluscan fauna has been analysed (Cerithioidea. Potamididae) et des Heterostropha sont décrits avec leur développement initial et leur paléoécologie est discutée. Trois modes by several previous workers. B r ia r t & C o r n e t (1870- différents de développement ontogénétique initial sont reconnus et les 1887) contributed an early comprehensive work on the inférences paléoécologiques sont discutées. gastropod fauna. C o s s m a n n (1915, 1924) first described Mots-clefs: Paléocène, Belgique, Gastéropodes saumâtres, développe­ the gastropods and subsequently the scaphopod and ce- ment, paléoécologie phalopod fauna. More recently G l i b e r t (1973) and V i- LATTE in M a r l i è r e (1977) have described the gastro­ pod fauna at Mons. The bivalve fauna has been de­ scribed by C o s s m a n n (1908), C h a v a n (1936, 1940) Z usant menfassung and more recently by G l i b e r t & V a n d e P o e l (1973) V i l a t t e M a r l i è r e Brackwassergastropoden aus dem frühen Mittelpaläozän des Dano- and by in (1977). In addition to Montiums von Mons, SE Belgien, werden hinsichtlich ihrer system­ the Mollusca further studies of the invertebrate fauna atischen Stellung revidiert. Vertreter der Unterklassen Neritimorpha at Mons have described the ostracods (M a r l i è r e , inklusive Monsneritina n. g. (Neritoidea, Neritidae), Caenogastropoda 1958; D a m o t t e , 1964; G o d f r i a u x & M a r l i è r e , inklusive Monspotamides n. g. (Cerithioidea, Potamididae) und Het­ erostropha werden hinsichtlich ihrer Paläoökologie charakterisiert. 1973). Drei Modi frühontogenetischer Entwicklung werden beschreiben und The brackish water gastropod fauna at Mons contains paläoökologische Schlussfolgerungen werden diskutiert. representatives of the subclasses Neritimorpha (order

Stichworte: Paläozän, Belgien, Brackwassergastropoden, frühonto- Neritida, superfamily Neritoidea), Caenogastropoda (Lit­ genetische Entwicklung, Paläoökologie torinimorpha, Risooidea, ; , 112 Thorsten KOWALKE

Cerithioidea; Pseudamauridae; , Bucci­ 1973 Otostoma cf. bicoronatum D e s m a y e s, 1864. G l i b e r t , noidea, Columbelloidea) and Heterostropha (Archaeopul­ p. 17, pi. 2, fig. 8. monata, Ellobioidea). Members of these taxa are charac­ terised by three distinct modes of early ontogenetic de­ Remarks. - G l i b e r t (1973) described a , based on velopment (for terminology and measurements of early a single specimen from the Coppée pit, coli. Houzeau, ontogenetic shells see B a n d e l , 1982; K o w a l k e , 1998a): IRSNB 5330, as Otostoma cf. bicoronatum. This would 1. Embryonic development with subsequent hatching of rather appear to belong to L i n n a e u s , 1758. The veliger larvae which are feeding on phytoplankton. In figured specimen closely resembles Nerita heberti from these the protoconch comprises a small embryonic the Lutetian of Hungary and juvenile specimens of N. shell, which is terminated by a thickened rim indicating heberti that were described as the synonymous Nerita the moment of hatching of the veliger from the egg. The hantkeni by S z ö t s ( 1953). Nerita bicoronata differs from subsequent larval shell formed by a planktotrophic N. heberti by eight coarse columella!' teeth of equal veliger usually consists of two or more whorls bearing size, whereas the two uppermost adapical columellar a characteristic ornament, which differs from the sculp­ teeth of N. heberti are always more strongly developed ture of the adult shell. The protoconch is usually termi­ than the lower ones. Otostoma U’A rc h i a c , 1859 with nated by a well developed sinusigera notch, indicating the type species Otostoma ponticum d ’ARCHiAC, 1859 the course of the pediveligers outer apertural lip. ( W e n z , 1938-1944, p. 418 f„ fig. 1020) differs by its 2. Embryonic development with subsequent hatching of very large oblique aperture, the fine axial ridges lecithotrophic larvae. This type of embryogenesis re­ crossed by equally strong spiral cords and the more sults from a yolk-rich development which produces a or less prominent nodes at the points of intersection of bulbous embryonic shell, that is succeeded by a larval the axial and spiral sculpture. shell usually less than two whorls. The shell is pro­ duced by a free-swimming larva, that does not feed on Genus M o n t f o r t , 1810 phytoplankton but on the remaining embryonic yolk. Theodoxus Jubatus (B riart & Cornet, 1887) The transition from the embryonic to the larval shell is PI. 1, Figs. 1-4 indistinct. The sculpture of the larval shell is less characteristic than that occurring in planktotrophic 1887 fabula B r i a r t & C ornet, p. 35, p i. 2 1, fig. 3 a-f. larvae, and often represents a simplified version of 1915 Neritina fabula B riart & Cornet. - Cossmann, p. 45, that found in the adult. The transition to the adult shell pi. 3, figs. 54-58. is characterised by a rim on the shell, which is slightly 1973 Theodoxus (Vittoclithon'l)fabulus ( B r i a r t & Cornet). - thickened and very slightly sinuous. G libert, p. 18, pi. 2, fig . 10. 3. Direct development without inclusion of a free larval stage. In this instance the large embryonic shell com­ Material. - 12 specimens, Coppée pit, coli. Houzeau, prises usually not more than one and a half whorls. It is IRSNB IG 6544. IRSNB FI 6404. terminated by a more or less distinct rim indicating the course of the outer lip of the embryo’s aperture. This is Description. - The neritoid shell consists of about 3.5 a case of early ontogenetic development, in which the convolute whorls measuring up to 12 mm in width and gastropods hatch from the eggs as crawling young. 8 mm in height. The spire is only slightly emerging. The sculpture of the teleoconch whorls consists of dense In this systematic revision of the brackish-water gastro­ zigzag shaped dark brown stripes on a cream white pods from Mons, their early ontogenetic shells are de­ ground. The aperture is ovate and characterised by a scribed and the paleoecological implications of these are rounded, moderately thickened outer lip and a smooth discussed. slightly concave columellar septum, which is not dentate. The figured specimens are deposited at the Institut The columellar edge is not thickened by callus. Royal des Sciences Naturelles de Belgique (IRSNB FI The protoconch of about 1.25 whorls measures 0.62- 6404-6421). 0.63 mm at its maximum diameter; its initial cap is 0.07- 0.08 mm in width. The diameter of the first whorl is 0.4- 0.5 mm. Sculpture of the embryonic shell consists of an Systematic Palaeontology indistinct axial groove-ridge pattern that is concentrated on the lower half of the whorls. After 1.25 whorls Class Gastropoda crowded growth lines are visible and these grade into Subclass Neritimorpha the regular dense prosocyrt growth lines that occur on the Superfamily Neritoidea Rafinesque, 1815 teleoconch whorls. Family Neritidae Rafinesque, 1815 Subfamily Neritinae Rafinesque, 1815 Remarks. - T. fabulus represents the oldest known species ? Nerita heberti SzÖTS, 1953 of the genus Theodoxus with preserved protoconch. The size and dimensions of the protoconch are indicative of

1953 Nerita heberti S z ö t s, p. 30, 141 f., pi. 2, figs. 3-5. direct development with the hatching of crawling young, 1953 Nerita hantkeni SzÖTS, p. 3 0, 142, pi. 2, figs. 6-7. without the occurrence of a free planktonic veliger stage. Palaeocene brackish water Gastropoda 113

This mode of early ontogenetic development with the embryonic shell. Deianira S t o l i c z k a , 1859, with type formation of an embryonic shell having a characteristic species Rotella bicarinata Z e k e l i , 1852 from the Late groove-ridge pattern is a typical feature of the genus Gosau-Formation of Austria has prominent Theodoxus. It has been described in the type species columellar plaits and is distinguished by its rotelliform Nerita fluviatilis L i n n a e u s , 1758 by B a n d e l (1982). teleoconch, which is strongly carinate and where the The morphology of the teleoconch with a smooth colu­ inner teleoconch whorls are not dissolved (W e n z , 1938- mellar septum also indicates a relationship to the genus 1944, p. 434, fig. 1069). Theodoxus. Vittoclithon B a k e r , 1923 based on the Re­ cent Southeast Asian type species Monsneritina montensis (B r ia r t & C o r n e t , 1887) L a m a r c k , 1816 is recognised as a synonym of Neritina PI. 1, Figs. 5-7 L a m a r c k , 1816, which differs by the coarser dentition of the columella and by involute protoconchs with 1887 Neritina montensis B riart & Cornet, p. 36, pi. 21, fig. 4 characteristic sculpture reflecting an indirect develop­ a-c. B riart & Cornet. - Cossmann, ment (B a n d e l & R ie d e l , 1998;H a r z h a u s e r et al., in 1915 Neritina montensis press). p. 46, pi. 3, figs. 59-62. 1973 Neritoplica (?) montensis (Briart & Cornet). - Gli­ b e r t , p. 18, pi. 2, fig. 9. Genus Monsneritina n. g. 1977 Theodoxus (Vittoclithon) montensis (B riart & Cornet). - V i l a t t e in M a r l i è r e , p. 45f. Type species. - Neritina montensis B r ia r t & C o r n e t , 1887 from the Dano-Montian of Mons. Material. - 86 specimens, from the Goffint pit, coli. Derivado nominis. - Combination name using Mons, the Comet, IRSNB 1G 5496; 121 specimens, from Coppée type locality of the type species, with the modem genus pit, coli. Houzeau, IRSNB IG 6544, IRSNB FI 6405. Neritina, which has a similar teleoconch morphology. Description. - The small shell measures up to 8 mm in Diagnosis. - The small shell is formed of a few rounded width and 6 mm in height, consisting of about five convolute whorls that increase strongly in diameter. The rounded, strongly convolute whorls. The inner walls of inner walls of the protoconch and of the teleoconch are the protoconch and of the teleoconch are dissolved. dissolved. Sculpture of the teleoconch consists of dense Sculpture of the teleoconch consists of dense prosocyrt prosocyrt growth lines and irregularly arranged brown growth lines and brown coloured irregularly arranged stripes and dots on a cream white ground. The parietal stripes and dots on a creamy-white background. The and basal lip of the aperture are characterised by wing­ parietal and basal lips of the large aperture are charac­ like extensions. The slightly curving columella bears two terised by wing-like extensions. The slightly curving columellar plaits in the posterior third of the aperture that columella bears two columellar plaits in the posterior continue into the interior portion of the aperture with a portion that continue into the interior portion of the few coarse teeth anterior of them. aperture and are accompanied anteriorly by 5-6 coarse The protoconch in the type species consists of about teeth. three convolute whorls. The first 1.5 whorls are totally The neritimorph protoconch consists of about three covered by the succeeding ones and the last 1.5 whorls convolute whorls, which attain a maximum diameter of are less convolute. The surface of the whorls seems to be 0.48-0.5 mm. The first 1.5 whorls are totally covered by smooth. The protoconch is terminated by a thickened the later ones that are more or less convolute - the projecting rim. succeeding whorl covers the lower half of the preceding one. The whorl surface is corroded, but seems to be Differences. - The shape of the juvenile shell and the smooth. The protoconch is terminated by a thickened morphology of the protoconch are similar to the type projecting rim. species of the genus Neritina, Nerita pulligera L in n a e u s , 1758 from Southeast Asia as described by B a n d e l & Remarks. - The protoconch is indicative of a planktonic R ie d e l (1998, p. 179, fig. 4 C-E).N. pulligera differs veliger stage. The shape of the juvenile shell and the by the lack of columellar plaits and by a higher number of morphology of the protoconch are similar to the early weaker columellar teeth (W e n z , 1938-1944: p. 428, shell of the type species N. pulligera of the genus Ner­ fig. 1052 a, b). The protoconch differs by its weak axial itina. The wing-like extensions of the peristome similarly ridges on the larval shell. Neritoplica O p p e n h e i m , 1892 occur in modem Neritina (B a n d e l & K o w a l k e , 1999). with as type species Neritina uniplicata J. de C. S o w e r - Monsneritina n. g. appears to be ancestral to Neritina, b y , 1823 (W e n z , 1938-1944, p. 422, fig. 1031) differs by which is known from in Neogene tropical deposits. its rounded shell without wing-like extensions of the Monsneritina may have derived from the Cretaceous peristome, and having only one prominent columellar Neritoplica which characterised shallow marine and plait without any accompanying teeth. Theodoxus M o n t - brackish habitats of the Tethys and which has the similar f o r t , 1810 differs by its smooth columella and its direct feature of a columellar plait continuing into the interior mode of early ontogenetic development with an inflated portion of the aperture (K o w a l k e & B a n d e l , 1996). 114 Thorsten KOWALKE

Subclass Caenogastropoda Description. - A small turreted rissoiform shell of five Order G o l i k o v & S tarobogatov , 1975 slightly rounded whorls measuring up to 2.2 mm in height Superfamily G r a y , 1847 and up to 1.2 mm in width. The whorls are characterised Family Rissoidae G r a y , 1847 by a sutural ramp. The sculpture of the teleoconch whorls Genus Alvania Risso, 1826 consists of 26-27 straight axial ribs that are crossed by six Subgenus Arsenia M o n t e s e r a t o , 1890 equally strong spiral cords; the teleoconch base is orna­ Alvania (Arsenia) craticula (B r ia r t & C o r n e t , 1887) mented by six spiral cords. The height of the last whorl PL 2, Figs. 3-5 forms 60% of the total height of the shell. The ovate aperture is characterised by an incised parietal notch. A 1887 Rissoa craticula B r ia r t & C o r n e t , p. 8, pi. 19, fig. 5 a-c. slit-like umbilicus is visible. 1924 Alvania craticula (B r ia r t & C o r n e t ). - C o s s m a n n , The protoconch consists of 1.75 rounded whorls mea­ p. 82, pi. 5, figs. 58-59. suring 0.46 mm in height and with a maximum diameter 1973 Alvania (Arsenia) craticula (B r ia r t & C o r n e t ). - G l i­ of 0.45-0.46 mm. The diameter of the first whorl is b e r t , p. 24, pi. 3, fig. 7 0.31 mm and the width of the initial cap 0.1 mm. Sculp­ 1977 Alvania (Alvania) craticula (B r ia r t & C o r n e t ). - Vi- ture is not preserved. l a t t e in M a r l iè r e , p. 55f., pi. 2, figs. 11-12.

R em arks. - A. (A.) m ontensis differs from A. (A.) crati­ Material. - One specimen, Coppée pit, coll. Achat Piret, cula by its direct mode of early ontogenetic development 1RSNB FI 6406; 7 specimens, Coppée pit, coll. Vincent that omits a free swimming planktonic veliger stage. The & Collard, IRSNB 1G 3439; 20 specimens, Coppée pit, inflated embryonic shell indicates a development within coll. Lefèvre, IRSNB IG 6433. the egg capsule and hatching of crawling young. The teleoconch differs from that of A. (A.) craticula by its Description. -The small rissoiform shell comprises five shouldered whorls and by the more regular ornament of rounded, rapidly increasing whorls up to 3 mm in height equally strong axial and spiral elements. The teleoconch and 1.8 mm in width. The sculpture of the teleoconch sculpture is similar to that in the type species of the consists of 14-16 straight to slightly opisthocyrt axial ribs, subgenus A rsenia, A .( A.) punctura ( W e n z , 1938-1944, which are crossed by eight weaker spiral cords. The base p. 617, fig. 1719). This differs by its less shouldered is ornamented by six spiral cords. The last whorl forms teleoconch whorls, in possessing a more rounded aper­ about 60% of the total height of the shell. The ovate ture, and by its indirect early ontogenetic development aperture is characterised by an incised parietal notch. A that has a free planktonic veliger stage. slit like umbilicus is present. The conical protoconch consists of 2.3 rounded whorls Family F i s c h e r , 1885 measuring 0.34 mm in height and 0.36 mm in maximum Genus Stenothyrella W e n z , 1938 diameter. The maximum diameter of the first whorl is Stenothyrella pupiformis (B riart & Cornet, 1887) 0.16-0.17 mm and the width of the initial cap is 0.04 mm; PI. 2, Figs. 6-8 this first whorl is slightly pointed. The sculpture of the protoconch is not well preserved. The second whorl is 1887 ‘IBithinia pupiformis B r i a r t & Cornet, p. 28, pi. 20, fig. 13 a-c. characterised by remains of spiral rows of tubercles on 1924 pupiformis ( B r i a r t & Cornet). - Cossmann, the adapical half and spiral lines on the abapical half of p. 76, p i. 5, figs. 28-29. the whorl. The protoconch is terminated by a slightly 1973 Stenothyra pupiformis ( B r i a r t & Cornet). - G libert, sinuous thickened rim. p. 23f., pi. 3, fig. 4.

Remarks. - The protoconch is indicative of a free plank­ tonic veliger stage and closely resembles that of the type Material. - 25 specimens, Goffint pit, coli. Cornet, species of the Recent subgenus Arsenia, Turbo puncturus IRSNB IG 5496, IRSNB FI 6407. M o n t a g u , 1803 from the Mediterranean Sea, which has been recently described from the plankton of Banyuls- Description. -A very small solid shell with an elongated sur-Mer (Pyrénées-Orientales, S.France) by K o w a l k e ovate shape of 4-5 slightly rounded rapidly increasing (1998a, p. 70, pi. 9, fig. 9). The dimensions of the proto­ whorls, up to 1.8 mm in height and 0.8 mm in width. The conch and the shape of the embryonic shell are similar, shell is characterised by a short conical spire with a stout although the protoconch of the type species is slightly apex. The last whorl forms about 60% of the total height smaller. of the shell and narrows in its adapertural portion. Sculp­ ture of the teleoconch whorls consists of dense slightly

Alvania (Arsenia) montensis G l i b e r t , 1973 prosocyrt growth lines. The small aperture is oblique and drop-shaped with an acute parietal edge. It is charac­

1924 Turbella? pulchra C o s s m a n n , p. 8 1 , pi. 5 , figs. 5 4 -5 5 . terised by a slightly thickened parietal lip. A slit-like 1973 Alvania (Arsenia) montensis G l ib e r t , p. 2 4 f., pi. 3, fig. 8. umbilicus is visible. The protoconch comprises 1.5 flat smooth whorls, is Material. - 2 specimens, Coppée pit, IRSNB IG 3439. 0.19-0.2 mm in height and 0.26-0.27 mm in maximum Palaeocene brackish water Gastropoda 115

diameter. The maximum diameter of the first whorl is C o s s m a n n , 1888. Medoriopsis, with the type species 0.19 mm and the width of the initial cap 0.06 mm. The effusa D e s h a y e s , differs by possessing a stou­ onset of the teleoconch is indicated by crowded growth ter shell and in the lack of any spiral sculpture on the lines. teleoconch ( W e n z , 1938-1944, p. 514, fig. 1348). D. lineatus closely resembles slender brackish water littor- Remarks. — The smooth bulbous protoconch is indicative inids, e.g. the genera L ittoraria and Mainwaringia N e - of a direct development with individuals hatching as v i l l , 1885 from West African and Indo-Pacific m an­ crawling young. Stenothyrella pupiformis differs from groves ( R e i d . 1985, 1986a, b; Bandel & Kowalke, the type species Nematura lubricella S a n d b e r g e r , 1863 1999).L ittoraria is distinguished by its large broad (W e n z , 1938-1944, p. 588, fig. 1610) from the Late conical shell. Mainwaringia, with the Recent type spe­ of Hackenheim (Rhine-Hesse, Germany) by cies M. leithii (E. A. S m i t h , 1875), has a very similar its smaller size and by the more oblique aperture. Ste­ shell size and outline but differs in having a larger nothyra B e n s o n , 1856 with the type species Nematura more rounded aperture with a weaker columellar deltae B e n s o n , 1836 (W e n z , 1938-1944, p. 588, board. fig. 1609) differs by its larger size, by a less solid shell with more rounded whorls, its acute apex and by the very Genus C avilabium C o s s m a n n , 1888 large bulbous body whorl. Cavilabium microscopicum C o s s m a n n , 1924 PI. 2, Figs. 1-2 Superfamily Littorinoidea G r a y , 1840 1924 Cavilabium microscopicum C o s s m a n n , p. 89, pi. 6, Family G r a y , 1840 figs. 4 5 -4 6 . Genus Dissochilus C o s s m a n n , 1888 1973 Littorina (Cavilabium ) microscopica (Cossmann). - Dissochilus lineatus (B riart & Cornet, 1887) G l i b e r t , p. 19f., pi. 3, fig. 1.

1887 Lacuna lineata B r ia r t & C o r n e t , p. 6, pi. 19, fig. 12a-c. M aterial. - One specimen, Coppée pit, coll. G. Vincent & 1924 Dissochilus Houzeaui. - C o s s m a n n , p. 90, pi. 5, figs. 86- Collard, IRSNB FI 6408; 23 specimens, Coppée pit, coli. 87. 1973 Dissochilus lineatus (B r ia r t & C o r n e t ). - G l ib e r t , Th. Lefèvre, IRSNB IG 6433. p. 19, pi. 2, fig. 12 a-c. 1977 Medoriopsis (Medoriopsis) lineata (R ia r t & C o r n e t ). - Description. - A minute shell with six strongly convolute V il a t t e in M a r l iè r e , p. 46f., pi. 2, fig. 10. whorls up to 2 mm in height and 1.2 mm in width. The sculpture on the whorls forming the teleoconch consists Description. -The slender littorinid shell measures up to of dense prosocline growth lines with about eight spiral 9 mm in height and up to 3.5 mm in width. It consists of rows of slightly elongated pits on the anterior and poster­ six to seven high, only slightly rounded whorls. The last ior third of the whorls The central third is smooth. The whorl amounts about 50% of the total height of the shell. aperture is drop-shaped and with an incised parietal edge. Sculpture consists of 14-16 thin spiral cords, which may The parietal and columellar lips are bent. bear a fine nodulation and which are regularly arranged The 2.2 whorls of the protoconch are almost planispi- all over the whorls. The base is fine spirally sculptured. rally coiled, have a maximum diameter of 0.57 mm and The height of the aperture forms about 30% of the total are terminated by an un-thickened rim. The limited 0.75 height of the shell. It has elongated oval to subangular whorl forming the embryonic shell is sculptured by a shape and it is characterised by a small but well devel­ pattern of grooved ridges and has a maximum diameter oped anterior notch and by a pointed posterior edge. The of 0.12 mm with an initial cap 0.04-0.05 mm wide. The aperture is slightly detached from the spire. A slit-like diameter of this whorl is 0.15-0.16 mm. An indistinct rim umbilicus is present. terminates the embryonic shell. The larval shell of this species appears to be smooth. Remarks. - G l i b e r t (1973) assignedDissochilus lineatus to the family Lacunidae. According to P o n d e r ( 1976) and R em arks. - The larval shell is evidence of a planktonic R e id (1986a) Lacunidae and Littorinidae lack significant veliger stage. C. m icroscopicum is distinguished from the conchological and anatomical differences and thus should type species of C avilabium , Littorina bezanconi C o s s ­ be united. Dissochilus houzeaui as described by C o s s ­ m a n n , 1888 found in the Lutetian of the Paris Basin, by m a n n (1924) is represented by adult specimens with its less stout spire and its smaller aperture. Littorina larger more slender shells and stronger developed sculp­ F é r u s s a c , 1819, type species Turbo littoralis L i n n a e u s , ture (see G l i b e r t , 1973, p 19, pi. 2, fig. 12c).V il a t t e in 1758, differs in its larger size and by having more M a r l i è r e (1977) described a juvenile specimen as rounded whorls. The protoconchs of Littorina (L ittorina) Medoriopsis (Medoriopsis) lineata. The large embryo­ littorea (Linnaeus, 1758) ( K o w a l k e , 1998a, p. 66f„ pi. 9, nic shell is a single whorl and indicates its direct figs. 1-2) from the North Sea and L. (M ela rha ph) e ner­ development. As mentioned by G l i b e r t , the shape itoides (Linnaeus, 1758) ( K o w a l k e 1998a, p. 67, pi. 9, of the aperture in this species suggests it probably fig. 3) from the Mediterranean Sea, are of a similar size, belongs to Dissochilus rather than to Medoriopsis but can be separated by their more conical shape and the 116 Thorsten KOWALKE fine pitted sculpture present on their embryonic and larval Krumbachiella typica differs from the type species only shells. in its larger size. The protoconch of K. typica is un­ The small trochoidal littorinids P h il ip p i , known. 1846 and Paesiella N e v i l l , 1885 that occupy similar brackish habitats to Cavilabium, are often associated with Genus Cornelia M unier-Chalm as in F i s c h e r , 1885 . Bembicium which has an angular trochoidal Cometía malaisei ( B r i a r t & C o r n e t , 1870) shell occurred in the Late Oligocene of and is known to be a direct developer ( R e id , 1988). Paesiella 18 7 0 Fusus Malaisei B riart & Cornet, p. 19, pi. 2, fig. 2 a-c. differs from Cavilabium by its protoconch with a larval 1885 Cornetia modonensis M unier-Chalmas in F is c h e r , shell that has sculpture of wavy spiral ridges and which is p. 701. terminated by a marked sinusigera notch ( R e id , 1988; 1887 Cornetia modunensis M unier-Chalmas in Fischer. - K o w a l k e , 1998a,p. 68, pi. 9, fig. 16). B riart & C ornet, p. 32, pi. 2, fig. la-f. 1924 Fusus Malaisei B riart & Cornet. - Cossmann, p. 91, pi. 6, figs. 58-59. Order Cerithiimorpha 1924 Cornetia modunensis M unier-Chalmas in F is c h e r . Superfamily Cerithioidea F é r u s s a c , 1819 C o s s m a n n , p. 91, pi. 5, figs. 81-85. Family unknown 1973 Cornetia malaisei B riart & Cornet. - G libert, p. 34, Genus Krumbachiella Kowalke & Bandel, 1996 pi. 5, fig. 7. Krumbachiella typica (B riart & Cornet, 1887) 1977 Cornetia modunensis M unier-Chalmas in Fischer. - V i l a t t e in M arlière, p. 75f„ pi. 4, fig. 16. 1887 Keilostoma typica Briart & Cornet, p. 14, pi. 19, 1977 Cornetia? malaisei Briart & Cornet. - V ilatte in M arlière, p. 76f., pi. 4, fig. 17. fig. lOa-c. 1924 Paryphostoma typicum (Briart & Cornet). - Coss­ m a n n , p. 8 7 , pi. 6, figs. 1-2. Description. -The low conical shell comprises four to 19 7 3 Keilostoma typicum B r i a r t & Cornet. - G libert, p. 2 7 , five preserved rounded whorls rapidly increasing in dia­ pi. 3, fig. 13. meter. It measures up to 26 mm in height and 20 mm in width. Sculpture of the teleoconch whorls consists of four Description. - The large elongated conical shell com­ strongly developed spiral keels crossed by 7-12 equally prises about ten preserved straight to slightly convex strong or finer straight to slightly opistocyrt axial ribs. whorls measuring more than 40 mm in height. The whorls Points of intersection of the spiral and axial sculpture are are step-like, separated by deep sutures, with telescope­ slightly thickened. The base is sculptured by three spiral like covering of the preceding ones. Whorls are smooth keels. The height of the large last whorl forms about 60% aside from closely spaced slightly prosocyrt growth lines. of the total height of the shell. The large rounded to The height of the last whorl forms about 40% of the total inclined oval aperture is characterised by a small but well height of the shell. The rounded lozenge-shaped aperture developed anterior notch. is pointed and slightly notched in its posterior portion. It is characterised by a prominent varix-like thickening. Remarks. - The genus Cornetia was placed within the , subfamily Paludominae by G l i b e r t (1973, Remarks. - G l i b e r t ( 1 9 7 3 ) assigned “ Keilostoma” ty­ p. 34). Paludominae are based on the Recent Southeast picum B r ia r t & C o r n e t , 1 8 8 7 to the family Rissoidae Asian genus S w a i n s o n , 1840 with the type (Rissooidea). The large size and telescope-like morphol­ species Melania conica G r a y , 1847 (W e n z , 1938-1944, ogy of the teleoconch of this shell distinguishes it from p. 703, fig. 2026). Paludomus conicus shares the low any rissooid genus and indicates a relationship with the conical shape of the teleoconch with Cornetia, but Cerithioidea. The shell morphology of this species does differs by tear-shaped aperture that has a strongly not agree with the generic description of Keilostoma pointed acute parietal edge and by its lack of promi­ D e s h a y e s , 1 8 4 8 and the type species Bulimus turriculus nent axial sculpture on the teleoconch. Cornetia is BRUGUIÈRE, 1 7 8 9 from the French Lutetian (W e n z , 1 9 3 8 - based on C. modunensis B r i a r t & C o r n e t , 1887 from 1 9 4 4 , p. 6 2 5 , fig. 1 7 5 0 ). Keilostoma does not have a the Dano-Montian of Mons which is a synonym of C. telescope-like arrangement of its teleoconch whorls, malaisei (B r i a r t & C o r n e t , 1870) (G l i b e r t , 1973, which are ornamented by strong spiral cords. C o s s m a n n p. 34, pi. 5 , fig. 7). G l i b e r t (1973) mentioned the ( 1 9 2 4 ) assigned the species to the genus Paryphostoma synonymy of these taxa, but V i l a t t e in M a r l i è r e B a y a n , 1 8 7 3 , which actually represents a synonym of (1977) continued to use the separate species names. Keilostoma (see W e n z , 1938-1944, p. 6 2 5 ) . “ Keilosto­ C. modunensis includes morphs of C. malaisei that have m a " typicum closely resembles Krumbachiella K o ­ closer finer axial ribs. This feature is generally variable w a l k e & B a n d e l , 1 9 9 6 with the type species Eulima in C. malaisei and has a range of 7-12 axial ribs per conica Z e k e l i , 1 8 5 2 from the Late Cretaceous Gosau- whorl (G l i b e r t , 1973; V i l a t t e in M a r l i è r e , 1977). Formation of the Northern Alps (K o w a l k e & B a n d e l , Cornetia is very similar to the Cretaceous - 1 9 9 6 , p. 3 0 f., pi. 2 , fig. 4 , 7 ). The early ontogenetic shell genus Pyrgulifera M e e k , 1877, type species Melania of that species, indicating a direct development, has been humerosa Meek from the Cenomanian of Wyoming described by K o w a l k e ( 1 9 9 8 a , p. 4 0 , pi. 4 , fig. 9 ). (W e n z , 1938-1944, p. 705, fig. 2033) and is m ost prob- Palaeocene brackish water Gastropoda 117 ably synonymous, but the protoconch is unknown and 1 9 7 3 Clava (Striovertagus ) dumonti (Briart & Cornet). - its exact position within the Cerithioidea is unclear. G libert, p. 41, pi. 6, fig. 5. 1 9 7 7 Clava (Striovertagus) dumonti (B r ia r t & Cornet). - V i l a t t e in M arlière, p. 9 3f., pi. 6, figs. 10-13. Family H. & A . A d a m s , 1854 Genus M elanopsis F é r u s s a c , 1807 briarti C o s s m a n n , 18 8 8 Material. - 21 specimens, Goffint pit, coli. Comet, IRSNB IG 5 4 9 6 ; Coppée pit, 4 0 specimens, coll. Lefèvre, 1873 Melanopsis Férussac. - B riart & Cornet, IRSNB IG 6 4 3 3 , IRSNB FI 6 4 0 9 ; 31 specimens, coli. p. 71, pi. 7, figs. 7-9a-c. Vincent & Collard, IRSNB IG 3 4 3 9 , IRSNB FI 6 4 1 0 . 1888 Melanopsis Briani Cossmann, p. 286. 1897 Melanopsis Briarti Cossmann. - Munier-Chalmas, Description. - This turreted fusiform shell can be up to p. 86. 2 0 mm in height and 8 mm in width. It has about 2 0 1924 Melanopsis Briarti Cossmann. - Cossmann, p. 91, pi. 5, shouldered whorls with flat flanks that are separated by figs. 88-93. 1973 Melanopsis briarti M unier-Chalmas. - G libert, p. 34, deep sutures. Sculpture of the first teleoconch whorl pi. 5, fig. 6. consists of three spiral cords, which disappear on the 1977 Melanopsis briarti Cossmann. - V ilatte in M a r l i è r e , fourth whorl. 1 2 -1 4 straight axial ribs develop on the p. 7 4 fi third teleoconch whorl but become weaker by the sixth whorl and later vanish, resulting in a smooth shell. The Description.- The melanopsid shell measures up to aperture is ovate with its posterior-anterior axis being 15 mm in height and up to 7 mm in width. It comprises oblique to the main axis of the shell. The inner apertural about eight preserved whorls, separated by straight su­ lip may be covered by callus, the outer lip is sometimes tures. The last whorl has elongated oval shape, the spire is accompanied by a varix and a slight posterior notch is conical. The height of the last whorl forms about 80% of developed. The columella is characterised by a very weak the total height of the shell. The large aperture has slender columellar plait. A short but well developed anterior oval shape. It is characterised by a slight anterior sinus channel is bent backwards. and by a pointed posterior portion. A prominent parietal The protoconch comprises 1.5 rounded whorls that are callus pad is present. 0 .3 1 mm in height and attain a maximum diameter of 0 .2 7 mm. It is terminated by a slightly sinuous rim. The Remarks. -- Melanopsis briarti has been assigned to the maximum diameter measured for the first whorl was family Thiaridae, subfamily Melanopsinae by G l i b f . r t 0 .2 3 mm. The initial cap is 0 .0 9 mm wide. Sculpture is (1973, p. 34). Melanopsidae actually represent a family not preserved in any of the specimens. of the Cerithioidea well separated from the Thiaridae by conchological and anatomical features (Houbrick, 1988; Remarks. - The protoconch is indicative of a short le- K o w a l k e , 1998a).B r i a r t & C o r n e t (1873) assigned cithotrophic larval stage: the embryonic and larval shell this species to M. buccinoidea. This Recent species from are not differentiated but the protoconch is terminated by the Eastern Mediterranean differs in its considerably a slightly sinuous rim. The larva probably only spent a larger shell, which is characterised by a weaker callus short time within the plankton, feeding on embryonic regularly covering the columellar and parietal portion of yolk and without additional feeding on phytoplankton. the aperture and which is lacking the heavy callus pad in (Pseudaluco) dumonti has been assigned the parietal portion of the aperture (see H e l l e r et al. to Clava (Striovertagus) by G l i b e r t ( 1 9 7 3 ) . Clava is a 1999, fig. 4a). From the general shell characteristicsM. synonym of the modem genus S w a i n s o n , briarti could well be ancestral to Neogene smooth mel- 1 8 4 0 that can be recognised by its elongate sharply anopsids of the Central Paratethys and of the Mediterra­ reflexed anterior canal, a well developed anal canal and nean region (H arzhauser & K o w a l k e , 2001; H arzii au- a prominent columellar plait (H o u b r i c k . 1 9 7 8 ). Striover­ s e r et aí ., in press). M. buccinoidea may represent a relic tagus C h a v a n , 1 9 4 8 is a synonym of Pseudaluco with a of this diverse Cainozoic relation. type species jusseui M a y e r -E y m a r , 1 8 7 0 from the Lutetian of the Paris Basin. Pseudovertagus (Pseudaluco) tenuiplicatus ( B r i a r t & Family F é r u s s a c , 1819 C ornet, 1873) differs by its larger apical angle, the less Subfamily Cerithiinae F é r u s s a c , 1819 shouldered whorls and by a greater number of closely Genus Pseudovertagus V i g n a l , 1904 spaced axial ribs (G libert, 1973, pi. 6 , fig. 6 ) . P. (P.) Subgenus Psettdaluco C l a r k & DURHAM, 1946 Pseudovertagus (Pseudaluco) dumonti punctifibrus ( B r i a r t & C o r n e t , 1873) ( G l i b e r t , 1973, pi. 6, fig. 8) and P. (P.) quequeti ( B r i a r t & C o r n e t , ( B r i a r t & C o r n e t , 1873) PI. 3, Figs. 1-3 1873) (G libert, 1973, pi. 6 , fig. 9 ) with dense fine axial and spiral sculpture on each of the teleoconch whorls 1873 Cerithium dumonti B riart & Cornet, p. 61, pi. 12. could well be conspecific with P. (P.) duponti ( B r i a r t fig. 11, a-c. & C ornet, 1873) (G libert, 1973, pi. 6 , fig. 7 ) represent­ 1873 Cerithium tenuiplicatum var. B r ia r t & C o r n e t , p. 58 ing different ontogenetic stages of a single species. P. (P. ) (partim), pi. 10, fig. 12, a-c. dejaeri ( B r i a r t & C ornet, 1873) with coarse axial and 118 Thorsten KOWALKE spiral ribs on each teleoconch whorl has been attributed to of 8-10 preserved whorls, slightly rounded in the early Thericium by GLIBERT (1973, p. 44, pi. 6, fig. 10) and teleoconch, but flattened in the later teleoconch. A pro­ V i l a t t e in M a r l i è r e (1977, p. 84, pi. 7 , figs. 1, 5-7, 9- toconch is not preserved. The earliest preserved whorl 10). Thericium is a synonym of Cerithium Bruguière, measuring 0.4 mm in width has sculpture of three spiral 1789, and differs from Pseudovertagus in its aperture cords, of which the most abapical is the strongest. This with a parietal tooth and a crenulate outer lip. sculpture persists on the following two whorls. The next Pseudovertagus (Semivertagus) (Cossmann, 1889), type whorl characteristically has three equally strong cords species Cerithium unisulcata L a m a r c k from the Lutetian and a weaker cord just above the abapical suture. This of the Paris Basin, differs by its teleoconch sculpture of teleoconch whorl also bears 10 straight weak axial ribs close spiral cords and its lack of a columellar plait ( W e n z , that cross the upper three spiral cords. These ribs may 1938-1944, p. 763, fig. 2211).B riart & Cornet (1873) persist over each following whorl, or they may decrease described other specimens as Cerithium abnormis, C. during the subsequent ontogeny. More or less prominent elisae, C. gibberosa, C. edmonti and C. abnormae, which elongate nodes form at the intersection of the spiral and according to G l i b e r t (1973) represent species ofSemi­ axial sculpture. The following whorls are characterised vertagus. These “ species” could well represent different by the formation of weaker but distinct spiral cords in the ontogenetic stages of a single species Pseudovertagus intercalations of the primary spirals. On the last 2-4 (Semivertagus) urania (d ’ORBiGNY, 1850) ( G l i b e r t , teleoconch whorls the uppermost adapical intercalated 1973, p. 40, pi. 6, fig. 4). secondary spiral may become as strong as the primary spiral cords. The base is ornamented by up to five spiral Family Potamididae H. & A . A d a m s , 1 8 5 4 cords, of which the two peripheral cords are always the most strongly developed. The aperture has well developed Remarks. - Potamididae are confined to brackish water short anterior and posterior channels. The slightly convex habitats, especially mangroves, at least since the Late columella lacks a plait and may be covered by callus. Cretaceous (Coniacian). The oldest known potamidids with preserved protoconchs have been described from Remarks. - This species is characterised by a certain the Late Coniacian - Early Santonian of the Northern variability of the sculpture (G l i b e r t , 1973). Different Alpine Gosau Formation by K o w a l k e & B a n d e l morphs with intermediate features have originally been (1996). These inhabitants of brackish biotopes were well assigned to different species by B r ia r t & C o r n e t separated from the convergent that occur (1873): Morphs with broad axial ribs and thus pro­ in fully marine habitats. Recent Potamididae characterise nounced elongated nodes have been called Cerithium pan-tropical mangroves, with the exception of the genus ovalituberosum; those with more regular axial and spiral M o n t f o r t , 1810, of which Potamides conicus sculpture were called Cerithium móntense', and those with (B l a i n v i l l e , 1829) the only modern representative, a stronger spiral sculpture and weak axial ribs had been relict species of a diverse Cainozoic lineage, is wide­ assigned to Cerithium sexlinum. spread in comparably cold waters of the Mediterranean G r a y , 1847 is a synonym o f Potamides Sea and the Red Sea (K o w a l k e , in press a). B r o n g n i a r t , 1810, based on the European Oligocene species Cerithium lamarkii, B r o n g n i a r t , 1810 (K a d o l - Genus Granulolabium C o s s m a n n , 18 8 9 s k y , 1984;K o w a l k e 1998a;K o w a l k e , in press a). Gran­ Granulolabitim ovalituberosum ulolabium differs from Potamides in lacking a twisted (B r ia r t & C o r n e t , 1873) columella and a columellar plait. This genus is distin­ PI. 3, Fig. 4 guished by the formation of secondary spiral cords inter­ calated between the main primary spirals, whereas Pota­ 1873 Cerithium ovalituberosum B r ia r t & C o r n e t , p. 31, pi. 8, mides characteristically has four spiral cords and no fig. 6, a-c. secondary spirals. 1873 Cerithium sexlinum B r ia r t & C o r n e t , p. 33, pi. 9, fig. 7, a-c. Genus Monspotamides n. g. 1873 Cerithium móntense B r ia r t & C o r n e t , p. 50, p i. 11, fig 10 a-c. Type species. - Cerithium varians B r ia r t & C o r n e t , 1973 Pirenella (s. s.) montensis (B r ia r t & C o r n e t ). - G l i­ 1873 from the Dano-Montian of Mons. b e r t , p. 35, pi. 5, fig. 8. 1977 Pirenella (Pirenella) montensis (B r ia r t & C o r n e t ), - V il a t t e in M a r l iè r e , p. 79fi, pi. 4, figs. 1-4. Derivado nominis. - Named after the type locality Mons and the closely related type genus of the Potamididae. Material. - 5 specimens, Coppée pit, coll. Lefèvre, IRSNB IG 6433; 7 specimens, Coppée pit, coli. Chavan, Diagnosis. - This small to medium sized broad conical IRSNB IG 21735; 72 specimens, Coppée pit, coll. E. de shell commonly has about ten flat whorls. The last whorl Jaer, IRSNB IG 8261, IRSNB FI 6411. forms about half of the total height of the shell. The teleoconch is ornamented by 4-5 spiral cords of which Description. - An elongate tower-shaped shell up to the initial two spiral cords are always the most strongly 14 mm in height and 4.5 mm in width. It usually consists developed. Additional spiral sculpture consists of numer- Palaeocene brackish water Gastropoda 119 ous very fine spiral threads. These spirals are crossed by whorl. The two initial spiral cords are always the stron­ straight to slightly opisthocyrt axial ribs, with nodes gest. Additional spiral sculpture consists of numerous formed at the points of intersection. The uppennost ada- very fine spiral threads, usually only visible in juvenile pical row of nodes is strongly developed and produces a specimens. The spiral cords are crossed by 14-16 axial step-like outline to the shell. The base is ornamented by ribs, which are visible on the fourth whorl and grade into three spiral cords with the uppermost adapical as the most straight to slightly opisthocyrt axial ribs. These increase prominent. The subangular aperture has a well developed in number up to 20 in the course of the ontogeny. Nodes anterior channel and a thin slightly rounded outer lip. The are formed at the intersection of spiral and axial sculp­ straight columella bears a weak columellar plait. In the ture. The uppermost adapical row of nodes is the stron­ type species the protoconch consists of 1.5 rounded whorls gest developed, thus the shell may have step-like outline. ornamented by spiral ridges and intercalated fine spiral The base is ornamented by three spiral cords, of which the threads. It is terminated by a thin slightly sinuous rim. outer one is most prominent. The sub-angular aperture has a well developed anterior channel. The straight colu­ Differences. - S c h u m a c h e r , 1817, type mella bears a very weak columellar plait. species Murex fuscatus L in n a e u s , 1758 from the West The protoconch consists of 1.5 rounded whorls mea­ African Coast (W e n z , 1938-1944, p. 739, fig. 2141), dif­ suring about 0.26-0.28 mm in height and 0.28-0.3 mm in fers by its large, acute conical shell, a sculpture of spiral diameter, with an initial cap of 0.08-0.09 mm in width. rows of nodes or spines and by the thickened aperture The diameter of the first whorl is 0.23-0.24 m m . Sculp­ bearing a heavy callus pad (K o w a l k e , in press b). The ture consists of six coarse spiral ridges which are visible genus S w a in s o n , 1840, type species Strombus on the first half whorl and numerous very fine spiral palustris L in n a e u s , 1758 from the Indo-Pacific (W e n z , threads are intercalated between these. The protoconch 1938-1944, p. 746, fig. 2157), differs by its elongate is terminated by a slightly sinuous thin rim. conical shell, by its thickened aperture with a heavy callus and an extended outer lip (K o w a l k e , in press b). Pota­ Remarks. - Dimensions of the protoconch indicate a mides B r o n g n i a r t , 1810, type species Cerithium lamar­ lecithotrophic larval stage. Embryonic and larval shells kii from the European Oligocene (W e n z . 1938-1944, are not differentiated and the protoconch is terminated by p. 736, fig. 2132), differs by its slender elongate shell, a slightly sinuous rim. its regular sculpture of four spiral keels, the crowded V i l a t t e in M a r l i è r e (1977)assigned this species to sinuous growth lines on the later teleoconch whorls and the genus Sandbergeria , which differs by a higher num­ by the lower body whorl with its considerably smaller and ber of finer axial ribs and by its large oval aperture with a rounded aperture (K o w a l k e , in press a). Granulolabium slight anterior notch lacking a prominent canal ( C o s s ­ differs by its slender shell, the intercalation of secondary m a n n 1906), and belongs to the family (Cer­ spiral cords in the sculpture of the teleoconch whorls, and ithioidea). by its less angular aperture that lacks a columellar plait.

G enus Hadraxon Oppenheim, 1892 Monspotamides varians (B r ia r t & C o r n e t , 1873) PI. 3, Figs. 5-7 Hadraxon regularicostatum (B riart & C ornet, 1873) PI. 3, Figs. 8-9 1873 Cerithium varians B riart & C ornet, p. 34, pi. 9, fig. 3 a- c. 1873 Cerithium regularicostatum B riart & Cornet, p. 32, 1873 Cerithium Lorteti B riart & C ornet, p. 39, pi. 8, fig. 9 a- pi. 8, fig. 8, a-c. c (= juvenile varians). 1973 Harrisianella (Teliostomopsis) regularicostata ( B r i a r t 1973 Tympanotonos varians (B riart & Cornet). - G libert, & Cornet). - G libert, p. 38, pi. 5, fig. 15. p. 36, pi. 5, fig. 9. 1977 Harrisianella ( Teliostomopsis) regularicostata ( B r i a r t 1977 Sandbergeria varians (B riart & Cornet). - V ilatte in & Cornet). - V ilatte in M a r l i è r e , p. 85f., pi. 5, M arlière, p. 83f., pi. 5, fig. 1-5. figs. 18-19.

Material. - 6 specimens, Coppée pit, coll. Lefèvre, IRSNB Material. - 21 specimens, Goffint pit, coli. Comet, IG 6433; 86 specimens, Coppée pit, coli. Houzeau, IRSN B IG 5496, IRSNB FI 6414 - IRSNB FI 6415. IRSNB IG 6544; 173 specimens, Goffint pit, coli. Comet, IRSNB IG 5496, IRSNB FI 6412 - IRSNB FI 6413. Description. - The very slender shell contains more than 20 slightly rounded whorls. It measures up to 15 m m in Description. -This broad conical shell measures up to height and up to 4 mm in width. The first whorl of the 11 mm in height and 5 mm in width and consists of about teleoconch is characterised by dense growth lines and by ten f la t whorls. The height of the last whorl forms about the formation of two median spiral cords. Two weaker half of the total height of the shell. The onset of the spiral cords appear above the adapical and below the teleoconch is indicated by the formation of two strong abapical cord on the second teleoconch whorl. Twelve spiral cords. On the fourth whorl another weak spiral cord weak slightly opisthocyrt axial ribs occur and become is visible just above the abapical suture and 1-2 further equal in strength to the cords on the two subsequent cords are formed below the adapical suture on the fifth whorls. In the course of the sixth teleoconch whorl an­ 120 Thorsten KOWALKE other spiral cord appears between the uppermost and the 1977 Diastomella luciani (Briart & Cornet). - V ilatte in second adapical cord and a sixth spiral cord develops on M a r l i è r e , p. 86f., pi. 5, figs. 6-9. the eighth teleoconch whorl. The axial elements become the most dominate element of sculpture at the eighth Material. - 10 specimens, Coppée pit, coli. Vincent, teleoconch whorl. The points of intersection of spiral IRSNB IG 3423, IRSNB FI 6416. and axial sculpture may be nodose. On late teleoconch whorls the axial ribs do not cross the uppermost adapical Description. - A small turriculate shell of about 10 and the lowermost abapical cords. The base is ornamen­ slightly rounded whorls that are up to 6 mm in height ted by three spiral cords. The height of the last whorl and up to 2.5 mm in width. The sculpture of the first forms less than 30% of the total height of the shell. It has teleoconch whorl consists of two median spiral keels and a small roundish fragmented aperture with a notch or numerous very fine spiral threads. On the sixth teleo­ short channel in the anterior portion. conch whorl another spiral keel becomes visible just The protoconch is fragmented. It comprised about 1.8 above the adapical suture. Six straight to slightly opistho- rounded whorls measuring about 0.3 mm in both height cline axial ribs appear on the third teleoconch whorl and and in maximum diameter. The initial cap is about 0.1 mm cross the two upper spiral keels. Prominent nodes are wide. The sulpture is not preserved. The transition to the formed at the points of intersection of the spiral and axial teleoconch is indicated by a thickened sinuous rim. sculpture. This type of sculpture persists over all the teleoconch whorls. The height of the last whorl forms Remarks. - The morphology of the protoconch indicates a about 40% of the total height of the shell. Only fragments lecithotrophic larval development. The dimensions of the of the aperture are preserved and these seem to indicate protoconch and the sinuous transition to the teleoconch the lack of any thickening and the presence of a well reflect a free swimming larval stage, during which the developed anterior channel. larva fed on embryonic yolk without additional feeding The protoconch of 1.5 slightly rounded whorls mea­ on phytoplankton. sures 0.21-0.22 mm in height and 0.24 mm in maximum Hadraxon resembles the Eocene Genus Harrisianella diameter. The first whorl has a maximum diameter of O l s s o n , 1929, type speciesH. peruviana O l s s o n ( W e n z , 0.19 mm and the width of the initial cap is 0.09 mm. 1938-1944, p. 752, fig. 2178) from the Eocene of Sculpture is not preserved. Peru, with similar slender multi-whorled shell and low body-whorl, which has been classified within the Dias­ Rem arks. - The protoconch is indicative of direct devel­ tomatidae by W e n z , (1938-1944).Harrisianella differs opment without the inclusion of a free-swimming veliger in its cylindrical shell with flatter whorls, and by the stage. teleoconch sculpture of sickle shaped axial ribs, that are deeply incised below the adapical suture, resulting Diastomella tenuicula (B riart & Cornet, 1877) in a prominent row of tubercles beneath that suture. PI. 4, Fig. 1 The aperture of Harrisianella differs in having a dis­ tinct columellar plait. Harrisianella is actually con­ 1877 Cerithium tenuiculum B riart & Cornet, p. 61, pi. 17, fig. 6 a-c. sidered an Eocene Tethyan subgenus of 1973 Diastomella tenuicula (B riart & Cornet). - Glibert, S w a i n s o n , 1840 by K o w a l k e (in press b), a potamidid p. 38, pi. 5, fig. 15. genus with Recent Indo-Pacific and tropical American 1977 Diastomella tenuicula ( B r i a r t & Cornet). - V ilatte in distribution. M a r l i è r e , p. 86f„ pi. 5, fig. 6-9. Teliostomopsis C h a v a n , 1952 is a synonym ofHadra­ 1977Diastomella chavani V i l a t t e in M a r l i è r e , p. 88, pi. 5, xon O p p e n h e i m , 1892, type species Hemisinus csinger- figs. 10-11, 14. vallensis T a u s c h , 1886, with similar dimensions to H. regularicostatum. But H. csingervallense from the San- M aterial. - Material is present from the Coppée pit, coli. tonian of Hungary differs from H. regularicostatum by its Lefèvre, IRSNB IG 6433, IRSNB FI 6413. greater number of closely spaced spiral cords and by the vanishing of axial ribs on late teleoconch whorls (B a n d e l Description. - The small slender shell measures up to & R i e d e l , 1994, pi. 6, figs. 5-7). The protoconch of the 6 mm in height and 1.9 mm in width. It comprises 9-10 type species conforms to a direct development without slightly rounded whorls. Sculpture consists of two strong the occurrence of a free larval stage (B a n d e l & R i e d e l , spiral keels and another weaker keel just above the aba­ 1994, pi. 6, figs. 1-3). pical suture, which is visible with the course of the sixth whorl. The spiral elements are crossed by about 20 very fine straight axial ribs. The last whorl forms about 40% of Genus Diastomella C h a v a n , 1952 the total height of the shell. The aperture has oval shape Diastomella luciani (B r ia r t & C o r n e t , 1873) PI. 4, Figs. 2-3 and a well developed anterior channel is present.

1873 Cerithium Luciani B riart & Cornet, p. 38, pi. 5, fig. 13. Rem arks. - The shell with similar height like D. luciani 1973 Diastomella luciani (Briart & Cornet). - Glibert, differs in having a considerably more slender shell with a p. 38, pi. 5, fig. 13. teleoconch sculpture of two spiral keels that are crossed Palaeocene brackish water Gastropoda 121 by a higher number of very weak axial ribs. D. chavani is spaced spiral rows of very fine indistinct pits. The very probably a synonym of D. tenuicula and a morph with large body whorl is well rounded and it is characterised sharp pronounced keels and no other differences. D. by an oblique drop-shaped aperture, which is slightly bent luciani and D. tenuicula have been placed within the anteriorly. The curved columella is slightly concave at its family by G l i b e r t (1973) and V il a t t e anterior end and the edge may be covered by callus. A slit in M a r l iè r e (1977). Diastoma D e s h a y e s , 1861, type like umbilicus is present. The first whorl is very bulbous, species Melania costellata Lamarck from the Lutetian has a maximum diameter of 0 .5 4 - 0 .5 5 mm and the width of the Paris Basin (W e n z , 1938-1944, p. 749, fig. 2169) of the initial cap is 0 .3 mm. The transition to the tele­ differs by its larger size and possessing a less regular oconch is indistinct. sculpture in which the axial ribs diminish on late tele­ oconch whorls. It is further distinguished by a large half­ Rem arks. - The dimensions of the first whorl indicate a moon shaped aperture without an anterior canal, but with direct development with a yolk rich embryogenesis and an incised pointed parietal edge and a distinct columellar subsequent hatching of crawling young. A free larval plait. D. luciani and D. tenuicula could well be placed stage was absent. within the family Potamididae. A. montensis differs from the type species A. depressa Lam arck, 1804 from the French Eocene by its smaller Family Pseudamauridae K o w a l k e & B a n d e l , 1996 size and by its less prominent callus pad (W enz, 1938- 1 9 4 4 , p. 1 0 2 0 , fig. 2 9 2 5 ) . G lobularia Swainson, 1840, Remarks. - The Pseudamauridae (Caenogastropoda) oc­ the type species Ampullaria sigaretina Lam arck, 1804 curred in brackish-water and are known from the Late (K abat, 1991,p. 4 3 0 ) , differs by its larger size, a shorter Cretaceous until becoming extinct after the Chattian more acute spire and by the large half moon shaped (Late Oligocene). They are distinguished from the con­ aperture with a columella, which curves convexly in its vergent Naticidae (Neomesogastropoda) by their fine- parietal portion and concavely in its anterior portion. A. pitted spiral ornament and a protoconch with a larval m ontensis could well be placed within the family Pseu­ sculpture of dense collabral axial ribs typical of plankto­ damauridae. trophic development (K o w a l k e & B a n d e l 1996,K o ­ w a l k e 1998b). Genus Amaurellina Fischer, 1884 Amaurellina julei (B riart & C ornet 1873) Genus Ampullina B o w d i c h , 1 8 2 2 PI. 4 , Figs. 6 - 7 Remarks. - Ampullella Cox, 1931 is a synonym ofAm­ 1873 Natica Julei B riart & Cornet, p. 7, pi. 6 , fig. 16, a-c. B o w d i c h , (W e n z , K a - pullina 1822 1938-1944, p. 1020; 1915 Amauropsella Julei (B riart & Cornet). - Cossmann, b a t , 1991, p. 426). A species described as Ampullella p. 68, pi. 4, figs. 5 1 -5 3 . lavalleei (B r ia r t & C o r n e t , 1877) by G l i b e r t (1973, 1973 Amaurellina (s. s.) julei (B riart & Cornet). - G libert, p. 59, pi. 7, fig. 9) does not agree with the generic p. 6 0 , pi. 7, fig. 10. description of Ampullina. This large thin shelled teleo­ conch with an acute spire angle, short pointed spire, M aterial. - 14 specimens, Coppée pit, coli. Houzeau, apically flat whorls and a large body whorl with wide IRSNB IG 6 5 4 4 , IRSNB FI 6 4 2 0 . rounded aperture should be assigned to the genus Crom- mium C o s s m a n n , 1888, type species Ampullina willeme- Description. - A rounded conical shell, up to 9 mm tii D e s h a y e s , 1825 from the French Lutetian (W e n z , in height and 6 mm in width, of about five rounded 1938-1944, p. 1025, fig. 2937). whorls. The step-like spire forms about 3 0 % of the total height of the shell. Sculpture consists of closely spaced prosocyrt growth lines and very fine spiral rows of pits. Ampullina montensis Cossmann, 1915 PI. 4, Figs. 4-5 The large body whorl is characterised by an oblique elongate oval aperture. The peristome is thin and frag­ 1873 ? Natica parisiensis B riart & Cornet, p. 2, pi. 6, fig. 1 mented. The columella has a slight concave curvature. A a-c. narrow umbilicus is present. The first whorl has a max­ 1915 Ampullina montensis C o s s m a n n , p. 67, pi. 4, figs. 43-45. imum diameter of 0 .5 4 - 0 .5 5 mm and the width of the 1973 Globularia montensis (Cossmann). - G libert, p. 59. initial cap is 0 .2 mm. The transition to the teleoconch is indistinct. Material. - 9 specimens, Goffint pit, coli. Comet, IRSNB IG 5496, IRSNB FI 6418 - IRSNB FI 6419. R em arks. - The dimensions of the first whorl are indica­ tive of a direct development without the intermission of a Description. - A small, globose, solid shell with a regular free larval stage, with the hatching of crawling young step-like spire, up to 8 mm in height and 6 mm in width, after a yolk-rich embryogenesis. of about six rounded whorls. The spire forms about 20% A. ju lei differs from the type species A. spirata L a ­ of the total height of the shell. Sculpture consists of m arck, 1804 that occurs in the Lutetian of the Paris Basin crowded slightly prosocyrt growth lines and closely (W enz, 1938-1944,p. 1 0 2 5 , fig. 2 9 3 6 ) , by its consider­ 122 Thorsten KOWALKE ably smaller shell. It can be distinguished from Ampullina which the teleoconch morphology resembles that of montensis by its more elongate, less solid shell, by its the Recent fusine genus Microcolus C o t t o n & G o d ­ slightly higher spire and by its less bulbous embryonic f r e y , 1931 from West Australia (W e n z , 1938-1944. shell. It could well be placed within the family Pseuda­ p. 1257, fig. 3582) and differs by its indication of a mauridae. However, a direct comparison of the early direct development. S. montensis has been assigned to ontogenetic shells is not possible, because A. julei lacks Cominella G r a y , 1850 by G l i b e r t (1973) and V i­ a larval shell with distinctive ornament. l a t t e in M a r l i è r e (1977). However,Cominella , type species Buccinum testudineum L a m a r c k , 1799 from Order Neogastropoda Recent, New Zealand (W e n z . 1938-1944, p. 1181, Superfamily Buccinoidea Rafinesque, 1815 fig. 3357) differs by its larger shell with teleoconch Family Rafinesque, 1815 whorls that are slightly concave in the upper portion Genus Suessonia C o s s m a n n , 1899 and convex in the lower portion. The sculpture con­ Suessonia montensis (B riart & Cornet, 1870) sists of strongly sinuous axial ribs. The aperture of PI. 4, Figs. 8-9 Cominella differs by its broad egg shape, the ridge above the fasciole and the presence of a well-developed 1870 Buccinum Móntense B r ia r t & C o r n e t , p. 30, pi. 2, pointed posterior channel. N u t t a l l & C o o p e r (1973) fig. 9, a-d. assigned the species to G.B. S o w e r b y , 1834, 1 9 7 3 Cominella montensis (B r ia r t & C o r n e t ). - G l i- type-species Buccinum undosum L i n n a e u s , 1758 from BF.RT, p. 6 7 , pi. 8 , f ig . 5 . Recent, South Pacific (W e n z , 1938-1944. p. 1197, 1977 Cominella montensis (B r ia r t & C o r n e t ). - V i­ fig. 3406). This differs by a lower conical shell, a higher l a t t e in M a r l i è r e , p. 120fi, pi. 8 , f ig s . 7-12. last whorl forming about 75% of the total height of the shell, a well-rounded extending outer lip and by the Material. - 20 specimens, Coppée pit, coli. Rutot, IRSNB presence of columellar plaits. IG 5611, IRSNB FI 6421.

Family Melongenidae G i l l , 1871 Description. - A solid, moderately slender buccinid shell Genus Levifusus C o n r a d , 1865 of ovate to spindle shape consisting of about 10 slightly Levifusus amplus (B riart & Cornet, 1870) rounded whorls up to 16 mm in height and 7 mm in width. The first teleoconch whorl is sculptured by ten indistinct 1870 Pleurotoma ampla B r ia r t & C o r n e t , p. 51. pi. 4, fig. 8. spiral cords that are crossed by 12 strong slightly opistho­ 1877 Fusus Potieri B r ia r t & C o r n e t , p. 19, pi. 14, fig. 9 a-c. cyrt axial ribs. The number of axial ribs increases up to 16 1887 Pleurotoma Dewalquei B r ia r t & C o r n e t , p. 29, pi. 15, during ontogeny. The uppermost spiral cords (1 - 4) are fig. 2. always the most strongly developed. The base is orna­ 1973 Levifusus amplus (B r ia r t & C o r n e t ). - G l ib e r t , p. 68, mented by ten well-defined, closely spaced spiral cords. pi. 8, fig. 7. The last whorl forms about 50-60% of the total height of the shell. The narrow ovate aperture has a well-developed Description. - The large melongenid species measures up anterior canal, slightly bent to the left side, has a char­ to 65 mm in height and 35 mm in width. The shell has acteristic slightly rounded outer lip and a thickened co­ about five preserved whorls. Sculpture consists of ten lumellar lip. tuberculate spiral cords with numerous fine spiral threads The protoconch consists of four slightly rounded intercalated. A median spiral cord is strongest developed. whorls, which appear to be smooth. It measures 1.4 mm The spiral sculpture is crossed by about ten broad slightly in height and has a maximum diameter of 0.83-0.84 mm. opistocyrt axial ribs. In the points of intersection of the The first whorl has a maximum diameter of 0.26 mm and median spiral and the axial ribs strong short spines are the width of the initial cap is 0.1 mm. The transition from developed. The last whorl forms about 70% of the total the embryonic to the larval shells is not preserved. A height of the shell. The large ovate aperture with rounded broken sinuous rim characterises the transition to the outer lip is characterised by a well-developed siphonal teleoconch. channel, which is slightly bent to the left side.

Remarks. - The protoconch is indicative of a free plank­ Remarks,. - G l i b e r t (1973) described the species as tonic veliger stage. 5. montensis differs from the type- Levifusus amplus. According to K o l l m a n n & P e e l species Fusus exigua D e s h a y e s , 1865 from the French (1983)L. amplus and another closely related New genus, Ypresian by its less slender shell, and its teleoconch cf. Levifusus C o n r a d , species 1 from the Paleocene of sculpture of closer and more slender axial ribs. The Nûgssuaq, West Greenland (K o l l m a n n & P e e l , 1983, protoconch with similar dimensions differs by compris­ p. 82, fig. 183) differ from the type-species of Levifusus, ing about 0.5 additional larval whorls. G l i b e r t (1973, Fusus trabeatus C o n r a d , 1865 from the Claibornian p. 68, text-fig. 39) gave a sketch of the protoconch of (Eocene) of Alabama (W e n z , 1938-1944, p. 1222, Suessonia exigua and compared it to the early ontoge­ fig. 3473), in their less inflated last whorl and by lacking netic shell of "Fusus" strictus B r i a r t & C o r n e t , 1870 a carina in the lower part and by a straight siphonal canal. (G l i b e r t , 1973, p. 67f., text-fig. 67, pi. 11, fig. 20) in The inclusion of L. amplus within a new genus is not Palaeocene brackish water Gastropoda 123

followed here. Kollmann & Peel indicated that the Genus Ellobium R ö d i n g , 1798 carina may be generally weak or even absent in other Ellobium olivaeformis (B r ia r t & C o r n e t , 1873) species of the genus L evifusus, thus represents a variable feature. The slightly more inflated body whorl of the type 1887 Melampus olivaeformis B riart & Cornet, p. 108, pi. 25, species and another weak carina of the lower part of the fig. 12 a-c. whorl may be taken into account to separate species but 1887 Melampus cochleatus B riart & Cornet, p. 109, pi. 25, are not very distinctive on genus level. Furthermore the fig. 13 a-c. 1973 Melampus olivaeformis B riart & Cornet. - Glibert, siphonal channel is not straight in case of the specimen p. 91, pi. 11, figs. 4a, b. figured by G l i b e r t (1973), but it is slightly bent. Thus L. am plus could well be congeneric with the type-species of Description. - The elongated conical shell is charac­ Levifusus, L. trabeatus. terised by an ovate body whorl and by a short conical spire and has about six preserved whorls. It measures up Superfamily Columbelloidea S w a i n s o n , 1840 to 15 mm in height and 7.5 mm in width. The shell Family G r a y , 1855 appears to be smooth aside from closely spaced slightly Genus Dolicholatirus B e l l a r d i , 1884 prosocyrt growth lines. The last whorl is very large, forms Dolicholatirus striatulus (B riart & Cornet, 1870) about 80% of the total height of the shell. The narrow half-moon shaped aperture is very high, reaching more 1870 Turbinella striatula B riart & Cornet, p. 10, pi. 1, fig. 6 a-c. than half of the total height of the shell. It is characterised 1877 Turbinella granulosa B r ia r t & C o r n e t , p. 10, pi. 14, by a slight broad anterior notch and by a pointed posterior fig. 1 a-c. portion. It bears a prominent horizontally arranged par­ 19 7 3 Latirus (Dolicholatirus) striatulus (B r ia r t & C o r n e t ). - ietal plait and a weaker columellar plait, which is orien­ G l ib e r t , p. 6 9 , pi. 8, fig. 8. tated towards the spire. The columellar and parietal por­ tion of the aperture are covered by callus. Description. — The fasciolariid shell measures up to 35 mm in height and 13 mm in width. It has about eight Remarks. - B r ia r t & C o r n e t ( 1887) described Melam­ preserved slightly rounded whorls. Sculpture consists of pus olivaeformis and M. cochleatus and assigned these numerous fine tuberculate spiral threads crossed by 6-8 species to the genus Melampus M o n t f o r t , 1810 [Mel­ strong straight axial ribs. The last whorl forms about 60% ampinae, attributed to Melampodinae by G l i b e r t (1973) of the total height of the shell. The large narrow aperture and W e n z & Z il c h (1959-1960)].G l i b e r t (1973) men­ is characterised by a straight columella, bearing two plaits tioned the variability of the species regarding the mor­ in its posterior portion, and by a well-developed straight phology of the last whorl and the height of the spire and siphonal channel. mentioned that these species are conspecific, with M. cochleatus representing varieties with stout apices and Rem arks. - G l i b e r t (1973, p. 69, pi. 8, fig. 8) described more rounded body whorl (p. 91, pi. II, figs. 4a, b). the species as Latirus (Dolicholatirus) striatulus, which G l i b e r t confirmed the systematic placement of M. oli­ differs from the type-species of Dolicholatirus, Turbinel­ vaeformis within the genus Melampus. Melampus, type la bronni M ichelotti, 1861 ( W e n z , 1938-1944, p. 1243, species Voluta coffea L i n n a e u s , 1758, Recent, from tro­ fig. 3543), from the Tortonian of Italy by its more pical America (W e n z & Z il c h , 1959-1960, p. 65f., rounded teleoconch whorls, and by the formation of finer fig. 211) differs in its less conical more rounded and closely-spaced spiral cords. Dolicholatirus should be re­ elongate ovate shape, in having one strong columellar garded as a genus which differs considerably from La­ plait, 1 -5 weaker parietal plaits and its weak teeth on the tirus M o n t f o r t , 1810, type-species Murex gibbulus interior labial part of the aperture. M. olivaeformis most G m e l i n , 1792 from Recent, Australia (cf. W e n z , 1938- likely belongs to the genus Ellobium, type species Voluta 1944, p. 1241, fig. 3538), in its crenulated outer apertural aurismidae L in n a e u s , 1758, Recent, from Southeast Asia lip. the lack of columellar plaits and in its very short (W e n z & Z il c h , 1959-1960, p. 77, Fig. 250), with a siphonal channel. Fasciolariidae are often connected to similar shell shape, and the characteristic presence of an environments, e.g. the Recent South Atlantic oblique columellar plait together with a stronger more genus Leucozonia G r a y , 1847 ( B a n d e l & K o w a l k e , horizontal parietal plait. Ellobium olivaeformis (B r ia r t 1999). & C o r n e t , 1873) differs from the type species by its smaller size, and by the absence of weak spiral granula­ tions on the teleoconch whorls. Subclass Fleterostropha Order Archaeopulmonata Superfamily Ellobioidea H. & A. A d a m s , 1855 Genus Auriculastra M a r t e n s , 1880 Family H. & A. A d a m s , 1855 Auriculastra ovata (B r ia r t & C o r n e t , 1887)

Rem arks. - The diverse ellobiid fauna of Mons consists 1887 Blauneria ovata B riart & Cornet, p. 106, pi. 25, fig . 13. of members of the subfamilies Ellobiinae, Pedipedinae 1973 Stolidoma ovata (B riart & Cornet). - G libert, p. 93, and Pythiinae ( G l i b e r t , 1973). fig. 13. 124 Thorsten KOWALKE

Description. -The small elongated conical shell with a Remarks. - B r ia r t & C o r n e t (1887) had assiged S. large cylindrical last whorl and a short conical spire has granda to Auricula L a m a r c k , 1799, a synonym ofEllo­ about six to seven preserved whorls. It measures up to bium. to which it has been attributed by G l i b e r t (1973). 7 mm in height and up to 3 mm in width. The spire whorls The species is distinguished from the type species Ello­ are slightly rounded. The shell appears to be smooth aside bium aurismidae by its elongate slender cylindrical shell from close-spaced slightly prosocyrt growth lines. The with lower body-whorl and probably belongs to the genus last whorl fontis about 70-80% of the total height of the Semiauricula C o s s m a n n , 1889 (subfamily Ellobiinae), shell. The large narrow aperture is characterised by a type species Auricula adversa D e s h a y e s , 1863 from the slight but broad anterior notch and by a pointed posterior French Thanetian. Semiauricula granda differs from the portion. It is characterised by a prominent plait in the similarly sized type species by the stronger axial ribs upper columellar portion. The aperture lacks a callus. present on the teleoconch whorls and its weaker colu­ mellar and parietal plaits. Remarks. - B r ia r t & C o r n e t (1887) originally assigned the species to Blauneria S huttleworth , 1854, which differs by its very thin, left winded shell with turreted Embryogenesis, Larval Ecology and Paleoecology spire. G l i b e r t (1973) assigned the species to the genus Stolidoma. S. ovata differs from the type species of the Sixteen brackish water gastropod species from Mons are genus Stolidoma D e s h a y e s , 1863, S. crassidens D e s ­ known from their protoconch morphologies. Only five m a y e s , 1863 from the French Thanetian (W e n z & Z il c h . species are characterised by an indirect mode of early 1959-1960, p. 73, fig. 237) by its less elongate shell, ontogeny with a free-swimming planktotrophic larval larger body whorl and shorter, more acute apex and by stage (Monsneritina montensis, Alvania (Arsenia) crati­ the lack of columellar and parietal callus. The columellar cula, Cavilabium microscopicum, Suessonia montensis, plait is less oblique and rather more horizontal. G l i b e r t Stolidoma acuta). Three species are characterised by a (1973) figured Stolidoma acuta (B r ia r t & C o r n e t , lecithotrophic larva, which only spend a very short time 1887) (G l i b e r t , 1973, p. 93, pi. 11, fig. 11) and 5. within the plankton, as indicated by larval shells that have cylindrata (B r ia r t & C o r n e t , 1887) (G l i b e r t , 1973, less than one whorl ( Pseudovertagus (Pseudaluco) du­ p. 93, pi. 11, fig. 12), subfamily Pythiinae. The systematic monti, Monspotamides varians, Hadraxon regularicosta­ place of these species within the genus Stolidoma could tum). Eight species underwent a direct development with be confirmed. The protoconch of S. acuta (G l i b e r t , the formation of large embryonic shell that indicates a 1973: pi. II, fig. 11) consists of two whorls with the yolk-rich embryogenesis with the subsequent hatching of initial 1.5 whorls being heterostrophic and is about crawling young without a planktonic veliger stage ( Theo­ 0.2 mm in both height and its maximum diameter. This doxus fabulus, Alvania (Arsenia) montensis, Stenothyrel­ indicates an indirect development with a planktonic ve­ la pupiformis, Dissochilus lineatus, Diastomella luciani, liger stage. The teleoconch shape of S. ovata indicates it Diastomella tenuicula, Ampullina montensis, Amaurelli­ most likely belongs to the genus Auriculastra M a r t e n s , na julei). 1880 (subfamily Ellobiinae), type species Auricula sub­ The predominance of direct developers and lecitho­ ula Quoy &Gmmard, 1832 (W e n z & Z il c h , 1959-1960, trophic species indicates a calm, coastal swamp environ­ p. 76, fig. 249; B a n d e l & R ie d e l , 1998, p. 188, fig. 8A). ment with reduced water energy (K o w a l k e & B a n d e l , Auriculastra ovata differs from the type species by its 1996). The coastal swamps probably extended far land­ smaller size and its stronger columellar plait. wards. This is also indicated by the presence of a diverse archaeopulmonate fauna (e.g. Ellobium olivaeformis, Auriculastra ovata, Semiauricula granda). Archaeopul­ Genus Semiauricula C o s s m a n n , 1889 monata characterise the landward part of coastal swamps Semiauricula gratula (B riart & Cornet, 1887) and mangroves, settling the uppermost intratidal to su-

1887 Auricula grandis B riart & C ornet, p. 90, pi. 25, fig. 1 a- pratidal portion (B a n d e l & R i e d e l , 1998;B a n d e l & b. K o w a l k e , 1999). This zone is also preferred by littorinids 1973 Ellobium grande (B riart & Cornet). - G libert, p. 93f., (Dissochilus lineatus, Cavilabium microscopicum). A p i. 11, fig. 14. good connection to the open sea existed as shown by the species with lecithotrophic and planktotrophic devel­ Description. - The slender elongate cylindrical shell opment, as these have had a marine larval stage after comprises about five slightly rounded whorls measuring hatching from egg masses within their adult brackish up to 35 mm in height and 18 mm in width. Sculpture habitat. The occurrence of Theodoxus fabulus and Mela­ consists of closely-spaced slightly prosocyrt growth lines nopsis briarti may point to a major fresh water influx. and of 8-10 straight axial ribs which vanish on the last This is also indicated by the presence of diminutive forms whorl. The last whorl forms about 60-70% of the total of Potamididae (Granulolabium ovalituberosum. Mon­ height of the shell. The height of the large ovate aperture spotamides varians, Hadraxon regularicostatum, Diasto­ amounts about half of the total height of the shell. It is mella luciani, Diastomella tenuicula) and Pseudamauri­ thickened by callus and characterised by a very weak dae (Ampullina montensis, Amaurellina julei) that reach columellar plait and a weak parietal plait. only half the size of their known Cretaceous, Eocene or Palaeocene brackish water Gastropoda 125

Recent relatives (K o w a l k e 1998a, b;K o w a l k e , in press morus J o u s s e a u m e , 1888 (cf. H o u b r i c k , 1985). Potami­ a, b). The occurrence of Cornetia, that most probably didae usually move during low tides preferring muddy represents a synonym of Pyrgulifera, indicates a calm, portions of the coastal swamp. This type of habitat is also landward portion of the coastal swamps - a similar en­ settled by Rissooidea, which in contrast also graze during vironment has been reconstructed for the Pyrgulifera- the high tides (B a n d e l & K o w a l k e , 1999). The extinct habitat of the Late Cretaceous of the Gosau and the family Pseudamauridae characterised the calm brackish Bakony Mountains (B a n d e l & R i e d e l , 1994;K o w a l k e lagoonal habitats and coastal swamps often associated & B a n d e l , 1996). with the bivalve genus Corbicula (K o w a l k e & B a n d e l , Most of the brackish water gastropods described were 1996; K o w a l k e , 1998b). The buccinid Suessonia, the herbivorous, either grazing on plants or microalgae as melongenid Levifusus and the fasciolariid Dolicholatirus their modern relatives: Neritidae occur on hard substrates were probably rare predators or scavengers of the brack­ as well as on soft bottom habitats (B a n d e l & R i e d e l , ish coastal swamp, comparable to modem neogastropods 1998;B a n d e l & K o w a l k e , 1999). Within the Littorini­ which marginally settle in the brackish milieu (B a n d e l & dae, Dissochilus closely resembles modern or K o w a l k e , 1999). Mainwaringia. These live on mangrove vegetation and are mainly active at low tide (R e i d , 1985, 1986a, b). Cavilabium in contrast resembles small littorinids such Acknowledgements as Bembicium and , that prefer coastal hard substrates (R e i d , 1988). Pseudovertagus (Pseudaluco) I would like to thank Annie V. Dhondt for her help during my dumonti (Cerithiidae) could have lived on intertidal hard work in the Royal Belgian Institute of Natural Sciences, and for substrates, or else on the roots of mangrove trees as their the possibility to borrow extensive material. Ronald J. Cleevely modem relatives belonging to the cerithiid genus Clypeo­ kindly reviewed and improved the manuscript.

References

A d a m s , H. & Adams, a., 1854. The genera of Recent Mollusca; Blainville, H.M., 1829. Dictionnaire des Sciences naturelles, arranged according to their organization. Van Voorst, London, Zoologie, Conchyliologie et Malacologie. Vol. 60. Levrault, vol. 2, 1-92. Strasbourg, 113 pp. A r c h i a c , E.J.A. d', 1859. Note sur le genre Otostoma. Bulletin B o w d ic h , T.E., 1822. Elements of Conchology, Including the de la Société Géologique de France, (2), 16: 871-879. Genera and the , Part I Univalves. J. Smith, Baker, H.B., 1923. Notes on the radula of the Neritidae. Paris, 83 pp. Proceedings o f the Academy o f natural Sciences, Philadelphia, B r i a r t , A. & C o r n e t , F.L., 1870-1887. Description des fos­ 75: 117-178. siles du Calcaire grossier de Mons. Gastéropodes. Mémoiresde B a n d e l, K., 1982. Morphologie und Bildung der friihontogen- l ’Académie royale des Sciences, des Lettres et des Beaux-Arts etischen Gehäuse bei conchiferen Mollusken. Facies, 7: 1-198. de Belgique, Ire partie, 36 ( 1870): 1-76; 2e partie, 37 (1873): 1- 94; 3e partie, 43 (1877): 1-73; 4e partie, 47 (1887): 1-128. B a n d e l , K. & K o w a l k e , T., 1999. Gastropod fauna of the Cameroonian coasts. Helgoland Marine Research, 53: 129- Brongniart, A., 1810. Sur les terrains de sédiment supérieur MO. calcareotrappéen du Vincentin, et sur quelques terrains d’Italie. Levrault, Paris, vi + 86 pp. B a n d e l , K. & R ie d e l, F., 1994. The Late Cretaceous gastropod fauna from Ajka (Bakony Mountains). A revision. Annalen des Bruguière, J.G., 1789. Encyclopédie méthodique ou par ordre Naturhistorischen Museums Wien, 96 A: 1-65. matières. Histoire naturelle des vers, des mollusques. Pan- coucke, Paris, 344 pp. B a n d e l , K. & R ie d e l, F., 1998. Ecological zonation of gastro­ pods in the Matutinao River (Cebu, Philippines), with focus on C h a v a n , A., 1936. Les Carditidés du Calcaire de Mons. Bulle­ their life cycles. Annales de Limnologie, 34, 2: 171-191. tin du Musée royal d ’Histoire Naturelle de Belgique, 12, 39: 1- 12. B a y an , J.F., 1873. Etudes faites dans la collection de l’Ecole des mines sur des fossiles nouveaux ou mal connus. Vol. 2. C h a v a n , A., 1940. Les Lucinidae du Montien de Belgique. Paris, 81-164. Bulletin du Musée royal d'Histoire Naturelle de Belgique, 16, 10: 1-24. B e l l a r d i , L., 1884.1 moUuschi dei terreni terziari del Piemonte e della Liguria. Vol. 4. Fasciolaridae e Turbinellidae. 62 C h a v a n , A., 1952. Quelques intéressants types de cérites. pp. Ermano Loescher, Torino. Cahiers géologiques de Thoiry, 15: 103-104. B e n s o n , W.H., 1836. Description of the shell and of C l a r k , B.L. & D u r h a m , J.W., 1946. Eocene Faunas from the Nematura, a new genus of Mollusca inhabiting situations sub­ Department of Bolivar, Colombia. Geological Society o f Amer­ ject to alternations of fresh and brackish water. Journal o f the ica Memoir, 16: 1-126. Asiatic Society, Bengal, 5: 781-783. C o n r a d , T.A., 1865. Catalogue of the Eocene and Oligocene B e n s o n , W.H., 1856. Descriptions of three new species of Testacea of the United States. American Journal of Conchol­ Paludomus from Burmah, and of some forms of Stenothyra ogy, 1, 1: 1-35. (Nematura ) from Pemang, Mergui, etc. The Annals and Maga­ C o s s m a n n , M., 1888. Catalogue illustré des coquilles fossiles zine o f natural History, 17, 2: 496-501. de FEocène des environs de Paris. Gastéropodes. Fase. 3. 126 Thorsten KOWALKE

Annales de la Société ravale malacologique de Belgique, 23: 3- G r a y , J.E., 1840. Synopsis o f the contents o f the British 324. Museum, ed. 42. London, iv + 248 pp. C o s s m a n n , M., 1889. Catalogue illustré des coquilles fossiles G r a y , J.E., 1847. A list of the genera of Recent Mollusca, their de l'Eocène des environs de Paris. Fasc. 4. Annales de la synonyma and types. Proceedings o f the Zoological Society of Société royale malacologique de Belgique, 24: 1-385. London, 15. 179: 129-219. C o s s m a n n , M., 1899. Essais de paléoconchologie comparée. G r a y , J.E., 1850. Figures of molluscous animals selected from Vol. 3. Paris, 201 pp. various authors. London, iv + 2 19 pp. C o s s m a n n , M., 1906. Essais de paléoconchologie comparée. G r a y , J.E., 1855. List o f the Mollusca in the collection o f the Vol. 7. Paris, 261 pp. British Museum. London, 23 pp. C o s s m a n n , M., 1908. Pélécypodes du Montien de Belgique. Harzhauser, M. & K o w a lk e , T., 2001. Early Miocene Mémoires du Musée royal d ’Histoire Naturelle de Belgique, 5, brackish-water Mollusca from the Eastern Mediterranean and 19: 1-76. from the Central Paratethys - a faunistic and ecological compar­ C o s s m a n n , M., 1915. Revision des scaphopodes, gastropodes ison by selected faunas. Journal of the Czech Geological Society, et céphalopodes du Montien de Belgique, première partie. 46 (34): 353-374. Mémoires du Musée royal d'Histoire Naturelle de Belgique, Harzhauser, M., K o w a lk e , T. & Mandic, 0., in press. Pan- 6,24: 1-71. nonian gastropods of Lake Pannon with special emphasis to C o s s m a n n , M., 1924. Revision des scaphopodes, gastropodes their early ontogenetic shells. Annalen des Naturhistorischen et céphalopodes du Montien de Belgique, deuxième partie. Museums Wien. Mémoires du Musée royal d ’Histoire Naturelle de Belgique, H e l l e r , J., S iv a n , N. & M o t r o , U.,1999. Systematics, Dis­ 34: 1-135. tribution and Hybridization of Melanopsis from the Jordan C otton, B.C. & G odfrey, F.K., 1931. South Australian shells. Valley (Gastropoda: Prosobranchia). Journal o f Conchology, The South Australian Naturalist, 13, 1: 5-23. 36, 5: 49-81. Cox, L.R., 1931. A contribution to the molluscan fauna o f the H o u b r ic k , R.S., 1978. The family Cerithiidae in the Indo- Laki and basal Khitar groups of the Indian Eocene. Transac­ Pacific, Part 1 : The genera Rhinoclavis, Pseudovertagus and tions o f the Royal Society o f Edinburgh, 57, 1: 25-92. . Monographs o f Marine Mollusca, 1: 1-130. D a m o tte , R., 1964. Contribution à l’étude des “ calcaires H o u b r ic k , R.S., 1985. Genus Clypeomorus Jousseaume (Cer­ montiens” du bassin de Paris: la faune d’Ostracodes. Bulletin ithiidae: Prosobranchia). Smithsonian Contributions to Zool­ de la Société géologique de France, 6, 7: 349-356. ogy, 403: 1-131. D e s h a y e s , G.P., 1839-1857. Traité élémentaire de Conchylio­ H o u b r ic k , R.S., 1988. Cerithioidean phylogeny. Malacological logie avec les applications de cette science à la Géologie. Paris. Review. 4: 88-128. D e s h a y e s , G.P., 1861-1865. Description des coquilles fossiles K a b a t , A.R., 1991. The classification of the Naticidae (Mol­ des environs de Paris. J.B. Baillière et fils, Paris, 5 vols., 2536 lusca: Gastropoda): Review and analysis of the supraspecific pp. taxa. Bulletin o f the Museum o f Comparative Zoology, 152, 7: 417-449. F é r u s s a c , J.B.L., 1807. Essai d’une méthode conchyliologique appliquée aux mollusques fluviátiles et terrestres. Paris, 142 pp. K a d o l s k y , D., 1984. Zur Taxonomie, Nomenklatur und strati­ graphischen Bedeutung einiger Mollusken der Inflaten-Schich- F é r u s s a c , J.B.L., 1819. Histoire naturelle genérale et particu­ ten und höchsten Cerithien-Schichten (Tertiär, Mainzer Beck­ lière des mollusques terrestres et fluviátiles. Paris, 128 pp. en). Mainzer geowissenschaftliche Mitteilungen, 13: 195-203. F is c h e r , P., 1884. Manuel de conchyliologie et de paléontolo­ K o l l m a n n , H.A. & P e e l, J.S., 1983. Paleocene gastropods gie conchyliologique ou histoire naturelle des mollusques vi­ from Nûgssuaq, West Greenland. Grönlands Geologiske Un- vants et fossiles. Savy, Paris, vol. 5, 609-688. dersögelse Bulletin, 146: 1-115. F is c h e r , P., 1885. Manuel de conchyliologie et de paléontolo­ K o w a l k e , T., 1998a. Bewertung protoconchmorphologischer gie conchyliologique ou histoire naturelle des mollusques vi­ Daten basaler Caenogastropoda (Cerithiimorpha und Littorini­ vants et fossiles. Savy, Paris, vol. 6, 689-896. morpha) hinsichtlich ihrer Systematik und Evolution von der GlLL, T., 1871. Arrangement of the families of Mollusks, pre­ Kreide bis rezent. Berliner geowissenschaftliche Abhandlun­ pared for the Smithsonian Institution by Theodore Gili. Smith­ gen, E 27: 1-121. sonian Miscellaneous Collections, 1871: 1-49. K o w a l k e , T., 1998b. Palaeoecology, protoconch morphology G l i b e r t , M„ 1973. Revision des Gastropoda du Danien et du and systematic position of the genus Pseudamaura P. F is c h e r , Montien de la Belgique, 1. Les Gastropoda du Calcaire de 1885 (Caenogastropoda: Pseudamauridae). Neues Jahrbuch fur Mons. Mémoires de I’ Institut royal des Sciences naturelles Geologie und Paläontologie, Monatshefte, 1998 (10): 577-586. de Belgique, 173: 1-116. K o w a l k e , T., in press a. Ontogenetical development and ecol­ G l i b e r t , M. & V a n d e P o e l, L., 1973. Les Bivalvia du Danien ogy of three species of the genus Potamides M o n t f o r t , 1810, et du Montien de la Belgique. Mémoires de l ’Institut royal des and a discussion of the evolutionary history of the Potamididae. Sciences naturelles de Belgique, 175: 1-89. Freiberger Forschungshefte. Reihe C. G m e lin , J.F., 1792. Linnaeus Systema naturae, aucta reformata. K o w a lk e , T., in press b. Cerithioidea (Caenogastropoda: Cer­ Vol. 2. Lipsiae, 885-1661. ithiimorpha) of Eocene Tethyan coastal swamps and their rela­ Godfriaux, I. & M a r l i è r e , R„ 1973. Relations entre Danien et tions to modem mangal communities. Bulletin o f the Czech Montien à Mons. Bulletin de la Société géologique de France, Geological Survey. (7), 13: 239-244. K o w a lk e , T. & B a n d e l , K., 1996. Systematik und Paläoöko­ G o lik o v , A.N. & Starobogatov, Y. I,. 1975. Systematics o f logie der Küstenschnecken der nordalpinen Brandenberg-Go- prosobtanch gastropods. Malacologia, 15, 1: 185-232. sau (Oberconiac/Untersanton) mit einem Vergleich zur Gastro- Palaeocene brackish water Gastropoda 127

podenfauna des Maastrichts des Trempbeckens (Südpyrenäen, P o n d e r , W.F., 1976. Three species of Littorinidae from South­ Spanien). Mitteilungen der Bayerischen Staatssammlung für ern Australia. Malacological Review, 9: 105-114.

Paläontologie und historische Geologie, 36: 15-71. Q u o y , J.R. & G a im a r d , J.P., 1826-1834 Voyage de la corvette Lam arck, J.B. de, 1799.Prodrome d’une nouvelle classifica­ l'Astrolabe. Vol 2. Tastu, Paris, 320 pp. tion des coquilles, comprenant une rédaction appropriée des R a f in e s q u e , C.S., 1815. Analyse de la Nature, ou Tableau de caractères génériques, et l’établissement d'un grand nombre de l’Univers des Corps organisés. Palermo, 244 pp. genres nouveaux. Mémoires de la Société d ’Histoire Naturelle R e id , D.G.. 1985. Habitat and zonation patterns of Littoraria de Paris, 1: 6 2 -9 1 . species (Gastropoda: Littorinidae) in Indo-Pacific mangrove L a m a r c k , J.B. de, 1804. Suite des mémoires sur les fossiles des forests. Biological Journal o f the Linnaean Society, 26: 39-68. environs de Paris. Annales du Muséum National d'Histoire R e id , D.G., 1986a. Mainwaringia N e v il l , 1885, a littorinid Naturelle, 5: 28-36. genus from Asiatic mangrove forests, and a case of protandrous L a m a r c k , J.B. de, 1816. Encyclopédie méthodique ou par ordre hermaphroditism. Journal of Molluscan Studies, 52: 225-242. de matières. Pancoucke, Paris, 97 pp. R e id , D.G., 1986b. The littorinid molluscs of mangrove forests Linnaeus, C., 1758. Systema naturae per régna tria naturae, in the Indo-Pacific region: The genus Littoraria. British Mu­ secundum classes, ordines, genera, species, cum characteribus, seum (Natural History), London, xv + 228 pp. differentiis, synonymis, locis. Tornus I, Editio Decima, Refor­ R e id , D.G., 1988. The genera Bembicium and Risellopsis (Gas­ mata. Laurentii Salvii, Holmiae, iv + 823 pp. tropoda: Littorinidae) in Australia and New Zealand. Records M a r l iè r e , R., 1958. Ostracodes du Bassin de Mons et résultats o f the Australian Museum, 40: 91-150. de leur étude. Mémoire de la Société belge de Géologie, de Risso, A., 1826. Histoire naturelle des principales productions Paléontologie et d'Hydrologie, 5: 1-53. de l’Europe méridionale et particulièrement de celles des en­ M a r l iè r e , R., 1977. Sur le stratotype du Montien à Mons. virons de Nice et des Alpes Maritimes. Levrault, Paris, 438 pp. Memoires explicatifs Cartes géologiques et minières de la R ö d in g , P.F., 1798. Museum Boltenianum sive Catalogus Ci- Belgique, 17: 1-230. meliorum e tribus regnis naturae. Pars secunda. J.C. Trappi, M a r t e n s , E. von, 1880. Mollusken. In: M ö b iu s , K., Beiträge Hamburg, vii + 109 pp. zur Meeresfauna der Insel Mauritius und der Seychellen. Ber­ lin. 179-343. S a n d b e r g e r , F., 1863. Die Conchylien des Mainzer Tertiär­ beckens. Wiesbaden, Lief. 8, p. 271-468. M a y e r -E y m a r , K .. 1870. Descriptions des coquilles fossiles S c h u m a c h e r , C.F., 1817. Essai d’un nouveau système des des terrains tertiaires inférieurs. Journal de Conchyliologie, 18: 323-338. habitations des vers testacés. Schultz, Copenhagen, iv + 287 pp. S huttleworth , R. J., 1854. Beiträge zur näheren Kenntnis der M e e k , F.B., 1877. Paleontology. U.S. Geological Exploration 40th Parallel Report, 4(1): 1-197. Land- und Süßwasser-Mollusken der Insel Portorico. -Mittei­ lungen der naturforschenden Gesellschaft , Bern 1854: 33-56. M ichelotti, G., 1861. Etude sur le Miocène inférieur de l’Italie septentrionale. Goosjes, Harlem, 183 pp. S m it h , E.A., 1875. Descriptions of some new shells from Kerguelen’s Island. The Annals and Magazine o f natural His­ M o n t a g u , G., 1803. Testacea Brittannica, or natural history of tory, 16, 4: 67-73. British shells. J.S. Hollis, Romsey, xxxviii + 610 pp. S o w e r b y , G.B., 1834. The genera of recent and fossil shells, for M o n t f o r t , P.D. de, 1810. Conchyliologie systématique et clas­ the use of student in conchology and geology. 42. London. sification méthodique des coquilles. F. Schoell, Paris, 678 pp. S o w e r b y , J. de C., 1823. The Mineral Conchology of Great M onteserato, T.A. di, 1890. Conchiglie delia profundita del Britain; or coloured figures and descriptions of those remains of mare di Palermo. Naturalista Siciliana, 9: 140-191. Testaceous animals or shells, which have been preserved at M unier-Chalmas, E., 1897. Notes préliminaires sur les assises various times, and depths in the earth. B. Meredith, London, montiennes du bassin de Paris. Bulletin de ¡a Société géologi­ vol. 4, 384-407. que de France, (3), 25: 82-90. S o w e r b y , J. de C., 1825. The Mineral Conchology of Great N e v il l , G., 1885. Hand list of Mollusca in the Indian Museum, Britain; or coloured figures and descriptions of those remains of Calcutta. II Gastropoda. Government Printer, Calcutta, x + 306 Testaceous animals or shells, which have been preserved at pp. various times, and depths in the earth. B. Meredith, London, N u t t a l l , C.P. & C o o p e r , J., 1973. A review of some English vol. 5, 486-503.

Palaeogene Nassariidae, formerly referred to Cominella. Bulle­ S t o l ic z k a , F., 1859. Über eine der Kreideformation angehörige tin o f the British Museum (Natural History), Geology, 23, 3: Süsswasserbildung in den nordöstlichen Alpen. Sitzungsber­ 177-219. ichte der Kaiserlichen Akademie der Wissenschaften, mathe­ O ls s o n , A., 1929. Contributions to the Tertiary paleontology of matisch naturwissenschaftliche Classe, 38/23-28: 482-496.

Northern Peru; part 2: Upper Eocene Mollusca and Brachiopo­ S w a in s o n , W., 1840. A Treatise on Malacology; or the Natural da. Bulletins o f American Paleontology, 15: 69-117. Classification of Shells and Shell Fish. Longman, London, vii + Oppenheim, P., 1892. Ueber einige Brackwasser- und Binnen­ 419 pp. mollusken aus der Kreide und dem Eocän Ungams. Zeitschrift S z ö t s, E., 1953. Magyarország Eocén Puhatestüi. I. Gäntkör- der Deutschen Geologischen Gesellschaft, 44: 697-818. nyéki Eocén Puhatestüek. Geológica Hungarica. Series Pa- O r b ig n y , A. d’, 1850. Prodrome de Paléontologie. Paris, tome laeontologica, 22: 1-270.

2, 422 pp. T a u s c h , L., 1886. Über die Fauna der nicht marinen Ablager­ Philippi, R.A., 1846. Verzeichnis der in der Gegend von Mag­ ungen der oberen Kreide des Csingerthales bei Ajka im Bakony deburg aufgefundenen Tertiärversteinerungen. Palaeontogra- (Veszprimer Comitat, Ungarn). Abhandlungen der Kaiserli­ phica, 1: 4 2 -4 4 . chen und Königlichen Geologischen Reichsanstalt, 12: 1-32. 128 Thorsten KOWALKE

V ig n a l , L., 1904. Liste des coquilles de la famille des Cer- Thorsten K o w a l k e ithidés recueillis par M. Ch. Gravier aux environs de Djibouti et Geological-Paleontological Institute and Museum, d’Obok. Bulletin du Musée de la Histoire naturelle de Paris, University of Hamburg, Bundesstraße 55, D - 20146 Hamburg, 10: 354-359. Germany

W e n z , W.. 1938-1944. Gastropoda.In: S c h in d e w o l f , O.H. e-mail: [email protected] (Editor), Handbuch der Paläozoologie. Borntraeger, Berlin, 6 (1), 1-1639.

W e n z , W. & Z il c h , A., 1959-1960. Gastropoda.In: S c h in d e ­ w o l f O.H. (Editor), Handbuch der Paläozoologie. Borntraeger, Berlin, 6 (2), 1-834.

Z e k e l i , F., 1852. Die Gasteropoden der Gosaugebilde. Abhan­ dlungen der kaiserlichen und königlichen Geologischen Reich­Typescirpt submitted: May 15, 2001 sanstalt, 1,2: 1-124. Revised typescript received November 5, 2001.

Appendix

List of the mentioned gastropod taxa of Mons Pseudovertagus (Pseudaluco) dumonti (B riart & Cornet, 1873) Family Potamididae H. and A. A d am s, 1854 Family Neritidae Rafinesque, 1815 Genus Granulolabium C o ss m a n n , 1889 Subfamily Neritinae Rafinesque, 1815 Granulolabium ovalituberosum (B riart & Cornet, 1873) ? Nerita heberti S z ö ts , 1953 Genus Monspotamides n. g. Genus Theodoxus M o n t f o r t , 1810 Monspotamides varians (B riart & Cornet, 1873) Theodoxus fabulus (B riart & Cornet, 1887) Genus Hadraxon Oppenheim, 1892 Genus Monsneritina n. g. Hadraxon regularicostatum (B riart & Cornet, 1873) Monsneritina montensis (B riart & Cornet, 1887) Genus Diastomella C h a v a n , 1952 Superfamily Rissooidea G r a y , 1847 Diastomella luciani (B riart & CORNET, 1873) Family Rissoidae G r a y , 1847 Diastomella tenuicula (B riart & Cornet, 1877) Genus A ¡vania Risso, 1826 Family Pseudamauridae Kowalke & Bandel, 1996 Subgcnus Arsenia M onteserato, 1890 Genus Ampullina B o w d ic h , 1822 Alvania (Arsenia) craticula (B riart & Cornet, 1887) Ampullina montensis Cossmann, 1915 Alvania (Arsenia) montensis G l i b e r t , 1973 Genus Amaurellina F is c h e r , 1884 Family Stenothyridae F is c h e r , 1885 Amaurellina julei (B riart & Cornet 1873) Genus Stenothyrella W en z , 1938 Superfamily Buccinoidea Rafinesque, 1815 Stenothyrella pupiformis (B riart & Cornet, 1887) Family Buccinidae Rafinesque, 1815 Superfamily Littorinoidea G r a y , 1840 Genus Suessonia C o ss m a n n , 1899 Family Littorinidae G r a y , 1840 Suessonia montensis (B riart & Cornet, 1870) Genus Dissochilus C o ss m a n n , 1888 Family Melongenidae G i l l , 1871 Dissochilus lineatus (B riart & Cornet, 1887) Genus Levifusus C o n r a d , 1865 Genus Cavilabium C o ss m a n n , 1888 Levifusus amplus (B riart & Cornet, 1870) Cavilabium microscopicum C o ss m a n n , 1924 Superfamily Columbelloidea S w a in s o n . 1840 Superfamily Cerithioidea F é r u s s a c , 1819 Family Fasciolariidae G r a y . 1855 Genus Krumbachiella Kowalke & Bandel, 1996 Genus Dolicholatirus B e l l a r d i , 1884 Krumbachiella typica (B riart & Cornet, 1887) Dolicholatirus striatulus ( B r i a r t & CORNET, 1870) Genus Cornetia M unier-Chalmas in F is c h e r , 1885 Superfamily Ellobioidea H. & A. Adams, 1855 Cornetia malaisei ( B r i a r t & C o r n e t , 1870) Family Ellobiidae H. & A. A d a m s, 1855 Family Melanopsidae H. & A. A d a m s, 1854 Genus Ellobium R ö d in g , 1798 Genus Melanopsis F é r u s s a c , 1807 Ellobium olivaeformis ( B r i a r t & C o r n e t , 1873) Melanopsis briarti C o ss m a n n , 1888 Genus Auriculastra M a r t e n s , 1880 Family Cerithiidae F é r u s s a c , 1819 Auriculastra ovata ( B r i a r t & C o r n e t , 1887) Subfamily Cerithiinae F é r u s s a c , 1819 Genus Semiauricula C o ss m a n n , 1889 Genus Pseudovertagus V ig n a l, 1904 Semiauricula granda ( B r i a r t & C o r n e t , 1887) Subgenus Pseudaluco C lark & Durham, 1946 Palaeocene brackish water Gastropoda 129

Explanations of Plates

All figured specimens are deposited in the collections of the Institut Royal des Sciences Naturelles de Belgique (IRSNB FI 6404 - IRSNB FI 6421).

P l a t e 1 Figs. 1-4 — Theodoxus fabulus ( B r i a r t & C o r n e t , 18 8 7 ) 1 = juvenile specimen (IRSNB FI 6404) in apertural view; the shell measures 3.42 mm in width. 2 = apical view of the same specimen as in fig. 1; the shell measures 3.3 mm in maximum diameter. 3 = apex of the same specimen as in fig. 1 in lateral view showing sculptural details of the embryonic shell; the first whorl measures 0.44 mm in height (in the visible part). 4 = apex of the same specimen as in fig. I in apical view; the first whorl measures 0.47 mm in maximum diameter. Figs. 5-7 — Monsneritina montensis (B r ia r t & C o r n e t , 1887) 5 = juvenile specimen (IRSNB FI 6405) in apertural view; the shell measures 2.2 mm in width. 6 = apex of the same specimen as in fig. 5 in apical view showing the transition from the protoconch to the teleoconch; the protoconch measures 0.5 mm in maximum diameter. 7 = apex of the same specimen as in fig. 5 in lateral view; larval whorls are partly covered by the succeeding ones; the protoconch measures 0.36 mm in maximum width (in the visible part).

P l a t e 2

Figs. 1-2 — Cavilabium microscopicum C ossm a n n i , 1924 1 = specimen (IRSNB FI 6408) in apertural view; the shell measures 1.66 mm in height. 2 = apex of the same specimen as in fig. 1; the smooth protoconch measures 0.57 mm in maximum diameter. Figs. 3 -5 — Alvania (Arsenia) craticula ( B r i a r t & Cornet, 1887) 3 = juvenile specimen (IRSNB FI 6406) in apertural view; the shell measures 2.87 mm in height. 4 = apex of the same specimen as in fig. 3 in lateral view; the protoconch comprises 2.3 whorls, it measures 0. 34 mm in height. 5 = apex of the same specimen as in fig. 3 in apical view; the protoconch measures 0. 36 mm in maximum diameter. Figs. 6-8 — Stenothyrella pupiformis ( B r i a r t & C o r n e t , 1873) 6 = specimen (IRSNB FI 6407) in apertural view; the shell measures 1.28 mm in height. 7 = apex of the same specimen as in fig. 6 in lateral view; the onset of the teleoconch is indicated by crowded growth lines; the protoconch measures 0.2 mm in height. 8 = apex of the same specimen as in fig. 6 in apical view; the first whorl measures 0.19 mm in maximum diameter.

P l a t e 3

Figs. 1-3 — Pseudovertagus (Pseudaluco) dumonti ( B r i a r t & Cornet, 1873) 1 = juvenile specimen (IRSNB FI 6410) in apertural view with gradual loss of teleoconch sculpture in the course of the ontogeny; the height of the shell amounts 8.3 mm. 2 = juvenile specimen (IRSNB FI 6409) showing the development of the early teleoconch sculpture; the shell measures 3.2 mm in height. 3 = apex of the same specimen as in fig. 2 in lateral view; a slightly sinuous rim is indicating the transition from the protoconch to the teleoconch; the protoconch measures 0.31 mm in height. Fig 4 — Granulolabium ovalituberosum (B r ia r t & C o r n e t , 1 8 7 3 ) 4 = specimen (IRSNB FI 6411) in apertural view showing the sculptural development of the teleoconch whorls; the height o f the shell amounts 13,2 mm. Figs. 5-7 — Monspotamides varians ( B r i a r t & C o r n e t , 1873) 5 = juvenile specimen (IRSNB FI 6412) in apertural view; the height of the shell amounts 6.7 mm. 6 = juvenile specimen (IRSNB FI 6413) in apertural view; the shell measures 3.65 mm in height. 7 = apex of the same specimen as in fig. 6 in lateral view showing sculptural details of the protoconch and transition to the teleoconch; the protoconch measures 0.28 mm in height. Figs. 8-9 — Hadraxon regularicostatum ( B r i a r t & C o r n e t , 1873) 8 = juvenile specimen (IRSNB FI 6414) in apertural view; the shell measures 3.86 mm in height. 9 = apex of a juvenile specimen (IRSNB FI 6415) in lateral view showing the thickened sinuous rim marking the transition to the teleoconch; the protoconch measures 0.27 mm (in the visible part). 130 Thorsten KOWALKE

P l a t e 4

Fig. 1 Diastomella tenuicula (B r ia r t & C o r n e t , 1877) 1 = specimen (IR S N B FI 6417) in apertural view with strong carination of the teleoconch whorls; the shell measures 3.3 mm in height. Figs. 2-3 Diastomella luciani (B r ia r t & C o r n e t , 1873) 2 = specimen (IR SN B FI 6416) in apertural view; the shell measures 4.36 mm in height. 3 = apex of the same specimen as in fig. 2 in apical view; the first whorl measures 0.19 mm in maximum diameter. Fig. 4-5 Ampullina montensis C o s s m a n n , 1915 4 = specimen (IR SN B FI 6418) in apertural view; the shell measures 6.8 mm in height. 5 = specimen (IR SN B FI 6419) in apical view with bulbous embryonic shell; the shell measures 3.6 mm in maximum d ia m e te r. Figs. 6-7 Amaurellina julei (B r ia r t & C o r n e t , 1 873) 6 = juvenile specimen (IR SN B FI 6420) in apertural view; the shell measures 3.65 mm in height. 7 = apex of the same specimen as in fig. 6 in apical view; the first whorl measures 0.54 mm in maximum diameter.

Figs. 8-9 Suessonia montensis (B r ia r t & C o r n e t , 1870) 8 = juvenile specimen (IR S N B FI 6421) in apertural view; the shell measures 4.18 mm in height. 9 = apex of the same specimen as in fig. 8 showing the thickened sinuous rim marking the transition to the teleoconch; the protoconch measures 1.42 mm in height. Palaeocene brackish water Gastropoda 131

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P l a t e 1 132 Thorsten KOWALKE

P l a t e 2 Palaeocene brackish water Gastropoda 133

P l a t e 3 134 Thorsten KOWALKE

P l a t e 4