Malacological Fauna Research Articles

Aegopinella bourdieri nov. sp. (Gastropoda: Zonitidae),une espèce nouvelle du Pléistocène normand (France)

St Pierre-lès-Elbeuf (Normandy, NE France) is a reference site for the middle and the upper Pleistocene of NW France. In the eastern part of the quarry, the paleosoils Elbeuf III and IV are truncated, white sands and a small tufa lay on Elbeuf IV. Similar deposits have been recognized at Vernon (Seine valley) and at Arrest (northern France). They are probably contemporaneous (Holsteinian) and each of them has yielded an interglacial malacological fauna. The faunal communities are interesting because they are composed by species living up to now in this country, by emigrated species and by fossil species. Among them, A. bourdieri is a new fossil taxa, endemic of Holsteinian tufas of Normandy. Associated with other species it characterizes homogeneous and well individualized communities. Nevertheless such moist interglacial open forest has been recognized also in tufas at Icklingham and at Hitchin (England). These occurrences lead to distinguish a biogeographical unit revealing particular paleoecological and paleoclimatological conditions during Holsteinian which has permitted the speciation of A. bourdieri in Normandy.

Mollusques et faune benthique du lagon de Takapoto

Mollusques et faune benthique du lagon de Takapoto. At least 93 species of Molluscs (58 Gastropods, 34 Bivalves, 1 Cephalopod) exist within the closed lagoon of the Takapoto atoll. The distribution by biotop and by bathymetric level is studied for the most abundant species ; they are Area ventricosa, Chama imbricata and Tridacna maxima for the endofauna, Rhinoclavis fasciatus, Vexillum cadaverosum, Fragum fragum and Lioconcha philippinarum for the epifauna. The Tridacna (14 million individuals — 530 tons of living matter) and the Area (38,5 millions — 340 tons) constitute most of the exemples of the malacological fauna, but the Mother-of-pearl, Pinctada margaritifera, intensively exploited in French Polynesia, is also the subject of quantitative estimates and breeding tests. Along with Molluscs, Corals (mainly Porites, Millepora, Montipora), Echinoderms (Halodeima atra) and Crustaceas (Brachiurs) represent a significant amount of the marine Invertebrates, while the sciaphil fauna (a few species of Sponges) is scarce compared to what is located on the outer slope. In this case we have a fauna typical of a closed atoll, where the uniformity and proliferation of 2 or 3 species in each zoological phylum is opposed to heterogeneousness and wealth of species found in open lagoons like Rangiroa and Mururoa.

Les gisements de Flour et de Perigoite 522 sur la haute terrasse inférieure de la rive gauche de la Moyenne Durance

The malacological fauna of basis bed of Flour site indicates a very watery forest environment. Palynological investigations on upper Flour and Périgoite stratigraphies have revelated a mediterranean woodland with some persistant exotic species. With its geological and paleontological characteristics, the inferior level of high terraces may be dated to a pre-mindelian period, before the first big glaciation of Southern Alps.

Le complexe Mindelien : II - La moyenne terrasse de l'Avre

The Middle Terrace at Amiens-St-Acheul and Avre valley is important. Firstly it is the type-site of the Middle Acheulean of St-Acheul ; it also shows up some of the climatic complexity of the late Mindel period. As Commont and Breuil suggested, it can probably be correlated with the Middle Terrace of South-East England which contains the famous Swanscombe site. The Middle Terrace of the Somme contains three units, placed in superposition. These are : 1) Coarse periglacial gravels transported by the Avre and the Somme, containing in its upper bed Middle Acheulean industry with some Levallois technique. 2) River sands, rich in pollen, fauna and small mammals, deposited in a moderately cold climate with a noticeable warm period in the middle of the deposit. These river sands are covered with loess and chalk-mud flows, whose fauna and sediment both show a definitely cooler climate. 3) An alteration surface in the form of a soil which is at the origin of the chocolate-brown clay nearly always disturbed by solifluxion in the early Riss. We may consider that this soil was formed at the Mindel-Riss interglacial period and is contemporary with Mediterranean or Lusitanian-type flora and malacological fauna at La-Celle-sous-Moret and Saint-Pierre-lès-Elbeuf in the Seine valley. This interpretation would put the periglacial deposits of the Middle Terrace into the Late Mindel (Anneyron level in Lower Dauphiné).

La faune malacologique

In the Masure sand mines, malacological fauna in each stratum denotes only a small change in climate-cool to cool temperate. The Jourdain quarry reveals faunal levels showing two cold phases separated by a warmer period, the latter notably more intense than was normal in a simple inter stade period.

Mollusques septentrionaux en Mediterranée occidentale: Datation par le 14C

In the Western Mediterranean, heaps of shells lying in the upper part of the continental slope between 90 and 340 m include boreal species which do not occur at present in this basin. The most common are Arctica arctica, Chlamys septemradiata, Modiolus modiolus. This malacological fauna seems to have been living when the sea-level was 80 m lower than at present. Series of 14C datings permit us to state precisely the age of this fauna, presumed to occur during the last Quaternary glaciation. The results obtained range from 31,500 ± 3,000 to 9,800 ± 200 years B.P. as far as boreal elements are concerned. However, the most frequent ages are between 9,800 ± 200 and 13,050 ± 300 B.P.. Thus, the boreal species seem to have had their highest development during the Würm IV when post-Glacial warming was under way. Among associated species still present in the Mediterranean, some shells are of the same age, while some are more recent: these species have survived post-Glacial times in a deep biotope which is not typical of the Mediterranean.

Societies and Academies

PARIS. Academy of Sciences, October n.—M. Henri Deslandres in the chair.—The president announced the death of Prof. Yves Delage.—G. Bigourdan: Corrections of the normal time-signals emitted by the Bureau international de 1'Heure from January 1 to March 19, 1920. Two tables give corrections of the ordinary partly automatic signals and of the beats 1 and 300 of the scientific signals.—Y. Delage: The application of the Pitot tube to the determination of the velocity of ships and to the registration of the distances traversed. The Pitot tube has been much used for the determination of fluid velocities with respect to immersed solid objects; it can also be utilised to determine the velocity of an object moving in still water, and its application to the measurement of the speed of a vessel is described in the present communication. Various devices are given for working the indicator at a distance from the Pitot tube, for rendering the indications independent of the variations of the load of the vessel, and for arranging that the movements of the needle shall be proportional to V and not to V2, so that from the continuous curve the total distance traversed can be estimated.—C. Moureti and G. Mignonac: The dehydrogenation of alcohols by catalvtic oxidation under reduced pressure. The general method described in a previous paper for the preparation of aldehydes and ketones by the catalytic oxidation of the corresponding alcohols by air in presence of reduced silver gives excellent results for the alcohols of low molecular weight, but the yield diminishes as the molecular weight of the alcohol increases. By working under reduced pressure {20 mm. to 40 mm.) this difficulty is removed.—P. Termier: The mylonites of the fourth Briangon écaille.—The secretary announced the death of M. Daniel Pauline Œhlert, correspondant for the section of mineralogy.—A. Chatelet: The enumeration and constitution of anv Abelian bodv whatever.—L. Antoine: The possibility of extending the homœomorphy of two figures to their vicinity.—J. Andrade: Friction and isochronism.—Ch. Déné: Waves of shock. The results of the study of a series of photographs of a stationary projectile placed in a stream of air moving at the rate of 45° metres per second. As the secondary waves are stationary, they can be more easilv photographed and studied.—W. A. Loth: A new method of navigation, permitting any vessel to enter and leave our (French) ports without risk when the usual means of determining the route are missing. An armoured cable traversed bv an alternating current with a musical frecmencv is laid on the sea-floor alonj the track to be followed, and a telephonic receiving apparatus of special design is carried bv the entering vessel. One oerson without specialised knowledge can brinf in a ship, as has been shown by oractiral trials at Brest.—R, Dubrisav: The application of a new method of physico-chemical volumetry. The solutions under examination are mixed with an equal volume of phenol and the temperature of miscibility is determined. The method has been applied to the study oi mixtures of solutions of sulphuric acid and sodium hydroxide, and two angular points are shown on the experimental curve corresponding to the formation of NaHSO4 and Na2SO4. It is noteworthy that when the neutralisation curve of sulphuric acid is followed by electrical conductivity or by cryoscopy no point corresponding to the formation of NaHSO4 is detected.—P, Bugnon: Causes of the transversal course of the libero-ligneous bundles at the nodes of the Gramineæ.—C. Beau: The trophic rôle of the endo phytes of orchids.—G. Astre: The biology of the molluscs in the French coast dunes and its relations with botanical geography. A discussion of the distribution of molluscs as affected by varying conditions of dryneÅ¡s. Apart from some secondary modifications of minor importance, the malacological fauna of the dunes is not one which has evolved in view of adaptation to a special medium, but a fauna already preadapted on the Mediterranean coasts, and which has simply extended its area of distribution.—P. Wintrebert: The aneural conduction of the ectoderm in the embryos of Amphibians.—M. Caullery and F. Mesnil: The existence of asexual multiplication in certain Sabellians (Potamilla Torelli and Myxicola dinardensis).—L. Besson: Relations between the meteorological elements and the number of deaths through inflammatory diseases of the respiratory organs in Paris. The data covered 522 weeks, and showed a clear relation between the number of deaths and the mean temperature three weeks before. From o° C. to 14° C. the fall in the number of deaths was proportional to the rise in temperature. Above 20° C. the deaths remained constant and independent of the temperature.

Societies and Academies

Societies and Academies

Paul Henri Fischer

THE Museum of Natural History of Paris has suffered a great loss in the person of Dr. Paul Henri Fischer, the well-known zoologist and palæontologist, who died on November 29, after a long and painful illness. Born at Paris, on July 7, 1835, he received his early classical and medical education at Bordeaux. He became Interne des Hôpitaux of Paris in 1859, and obtained his degree of Doctor of Medicine in 1863. The study of medicine did not prevent him from devoting himself also to that of the natural sciences; for in 1861 he entered as Demonstrator in the Laboratory of Palæontology of the Museum of Paris, under the direction of M. d'Archiac. His researches chiefly concerned the living and fossil mollusca, and from 1856 he edited the Journal de Conchyliologie in collaboration with M. Crosse. From the position of Demonstrator he rose to be aide-naturaliste (assistant), and studied with great success the marine animals of the coasts of France, their geographical and bathymetric distribution. He indicated the depths at which a large number of foraminifera, cœlenterata, echinodemata, mollusca, bryozoa, &c. can be collected on the coasts of the west of France. In collaboration with the Marquis de Folin he undertook the study of the animals dredged in the extremely interesting region of the Gulf of Gascony, to which the name “Fosse du Cap Breton” has been given. The two savants discovered a large number of forms hitherto unknown, and many which recalled species only known in the fossil condition. With M. Delesse he made researches on the submarine sediments of the French shores. He was elected member of the Commission of Dredging, and took part from 1880 to 1883, on board the Travailleur and the Talisman, in the celebrated expeditions directed by Prof. Milne Edwards. In the course of these expeditions he noted the enormous extension of a cold fauna characterised by boreal and arctic species, and reaching as far as Senegal, where it lives beneath a superficial fauna with intertropical characters. Among the writings of Dr. Fischer, which number not less than 300 titles, including books, pamphlets and memoirs, we may cite: “Paléontologie de I'Asie mineure” (in collaboration with MM. d'Archiac and de Verneuil); “Mollusques de Mexique et de I'Amerique Centrale”; “Species général et iconographie des coquilles vivantes”; “Animaux fossiles du Mont Léberon” (in collaboration with MM. Gaudry and Tournouer); “Paléontologie de I'île de Rhodes”; “Cétacés du Sud-Ouest de la France”; “Catalogue et distribution géographique des mollusques terrestres, fluviatiles et marins d'une partie de I'Indo-Chine; “Sur les caractères de la faune conchyliologique terrestre et fluviatile recemment éteinte du Sahara”; “Sur la faune conchyliologique de I'île d'Haïnan”; numerous memoirs on the malacological fauna of Lord Hudson Island (Pacific Ocean), of Cambodge, of the islands of the Caledonian Archipelago, of Aleutian islands, of the Bay of Suez, &c. In collaboration with M. E. L. Bouvier he published papers on the anatomical peculiarities of certain groups of molluscs. Finally, he wrote a remarkable treatise on conchology which has become classical (“Manuel de Conchyliologie et de paléontologie conchyliologique ou histoire naturelle des mollusques vivants et fossiles, suivi d'un appendice sur les Brachiopodes par Œhlert.” In this manual the author showed that the classification of molluscs ought to be based not alone on the form of the shell, but primarily on the anatomical characters.

On the abyssal malacological fauna of the Mediterranean

<i>On the abyssal malacological fauna of the Mediterranean</i>