Non-marine Mollusca Research Articles

Haemagglutinins from some British non-marine mollusca.

Abstract. 15 out of 29 species of British non‐marine Mollusca examined yielded agglutinins against human erythrocytes. Six had agglutinins of varying anti‐A specificities, one anti‐B, one anti‐A+B, one anti‐H and five of no evident specificity. Another agglutinated native erythrocytes without specificity, but did not agglutinate red cells treated with proteolytic enzymes or neuraminidase. A further species showed some evidence of possessing a blood group B‐like substance.

Haemagglutinins from some British Non-Marine Mollusca

Haemagglutinins from some British Non-Marine Mollusca

Interglacial deposits in Barnfield pit, Swanscombe, and their molluscan fauna

This paper describes the non-marine Mollusca of the Pleistocene terrace deposits of Barnfield pit, Swanscombe, and discusses their ecological and climatic significance. Biostratigraphical relationships with Hoxnian deposits at Clacton-on-Sea and at certain other sites in the lower Thames basin are examined. It is suggested that the Lower Gravel and Lower Loam of Barnfield pit were formed in the early-temperate substage of the Hoxnian interglacial (zone Ho II), whereas the Middle Gravels began to accumulate not before the end of the late-temperate substage (zone Ho III), and probably extend into the early-glacial substage of the succeeding glaciation. New evidence bearing on the dating of the Clacton Channel deposits is contained in the appendix. The Clactonian flint industry at the type site is shown to belong at least partly in subzone Ho IIb of the interglacial.

The Tertiary Non-Marine Mollusca of South America.

The Tertiary Non-Marine Mollusca of South America.

Late Pleistocene deposits at Wretton, Norfolk. I. Ipswichian interglacial deposits

Interglacial deposits found in the low terrace at Wretton, Norfolk, were formed in the zones II and III of the Ipswichian interglacial. The variety of sediments found is associated with the fluviatile environments of a meandering river. During zone II there was a regional mixed oak forest, with the local development of alder carr, fen, reedswamp and open water communities. During zone III the regional vegetation was more open and Carpinus became an important woodland tree. Locally, fen, reedswamp and open-water communities persisted, but alder carr was absent. The plants give some indication that the climate may have been more continental than at present, a number of species occurring which are not native to the British post-glacial flora but which have a wide distribution on the Continent. A brief comparison of the vegetational history is made with that of other Ipswichian interglacial sites in England and with the correlative Eemian interglacial on the Continent. The interglacial sections at Wretton form one of the richest Ipswichian sites for non-marine Mollusca so far found in England. The presence of a few more southern or more continental species, not now living in England, confirms that the climate was probably slightly warmer than at present, at least in summer. Numbers are large enough for satisfactory analysis in almost all sections, so that the environmental conclusion they suggest can be checked against those deduced from the plants. In general, these conclusions match and indicate a series of deposits laid down by a plant-rich Fenland river, a true ancestor of the present river Wissey, in its channel and neighbouring parts of its floodplain. The occurrence of brackish water species of Mollusca allows levels of marine influence to be clearly integrated with the vegetational history. Brackish horizons occur between - 1.95 m and +0.45 m O.D. in zone II b deposits, giving an indication of sea-level at this stage. The zone III deposits, although at a lower level, show no trace of brackish influences and a possible oscillation of sea-level is inferred.

The Tertiary non-marine Mollusca of South America

The Tertiary non-marine Mollusca of South America

Interglacial deposits at Ilford, Essex

At Ilford, Essex, organic sediments have been found beneath the brickearth, long famous for its rich mammalian fauna. Pollen analysis shows that these organic sediments and the lower part of the overlying brickearth were deposited during the Ipswichian (Last) Interglacial. The pollen diagrams show the vegetational succession typical of the first half of the interglacial, with pollen zones b, c, d, e and f , which cover the early treeless part of the interglacial and the change to forested conditions with Pinus and Quercus . The rich flora of macroscopic plant remains indicates that a climate with summers warmer than now obtain in the area prevailed probably in zone c and more certainly in the later zones. Analyses of the macroscopic plant remains and the non-marine Mollusca demonstrate that the organic deposits were formed in a large pond or a small stream, tributary to the Thames at that time. A rising base level, probably resulting from the rise in sea-level known to occur in zone f of the interglacial, caused the Thames floodplain to extend over the organic deposits, and brickearth was deposited up to a height of 42 ft. O.D. at least. The surface of the brickearth was contorted by cryoturbation during the Weichselian (Last) Glaciation. The Ilford temperate deposits are correlated with temperate fossiliferous deposits at Little Thurrock (Grays), and more tentatively, with temperate fossiliferous deposits at Erith, Crayford and Ebbsfleet. The consequences of the dating of the Ilford brickearth to the Ipswichian Interglacial for the terrace succession of the lower Thames valley are considered.

Non-Marine Mollusca and Quaternary Ecology

Non-Marine Mollusca and Quaternary Ecology

Pollen analyses of the cromer forest bed series in east anglia with an appendix on the non-marine mollusca

The deposits which have been analyzed lie on the coast between West Runton and Corton. No single pollen diagram shows the complete vegetational history of the period during which the Cromer Forest Bed Series was laid down, but, when considered together, the diagrams show evidence of a sequence which has been divided tentatively into three zones. The first of these (zone a) shows a predominance of Betula and then Pirns ; pollen of other trees is either absent or insignificant, and the non-arboreal pollen values are very high in the early part of the zone. Alnus is strongly represented throughout zone b, which shows the rise and subsequent decline of mixed-oak forest trees and a similar but later change in Picea . The mixed-oak forest trees disappear in zone c, Alnus and Picea decrease and probably disappear and Betula and Pinus return to dominance. It is possible that these three zones represent a sequence in time; if so, the changes reflect a climatic change from cool or cold conditions through a warm period to increasing cold. The pollen zones could not be related satisfactorily to the divisions of the Cromer Forest Bed Series which were established by Clement Reid. The vegetational zones of the Cromer Forest Bed Series are compared with those of other deposits which are believed to be of the same age or to belong to subsequent interglacials. It appears that the Cromerian diagrams have a number of features in common which may be used to distinguish them from diagrams referred to deposits of other interglacials. The non-marine molluscs found in the Cromer Forest Bed Series at West Runton are listed by Mr B. W. Sparks, who considers that they indicate the formation of that part of the deposit in a marsh cut by sluggish drainage channels.

A FLORA AND FAUNA FROM LATE PLEISTOCENE DEPOSITS AT SIDGWICK AVENUE, CAMBRIDGE

SUMMARY Recent excavations in Sidgwick Avenue, Cambridge, have exposed up to 5 metres of gravels of the Intermediate Terrace resting on Gault Clay. Low down in these gravels an almost complete bison skull was discovered associated with deposits containing non-marine Mollusca, while a few yards away at the same level deposits rich in macroscopic plant remains and Mollusca were found. Although no countable pollen was present, the general nature of the flora and fauna indicates cool to cold conditions, probably the Early-glacial phase immediately prior to the Last Glaciation.

The interglacial deposits at Stutton, Suffolk

As complete a series as possible of samples from the brickearth exposed on the northern bank of the Stour estuary at Stutton, Suffolk, has been taken and the contained non-marine Mollusca analysed. These show persisting and almost uniform river conditions but a steady climatic deterioration. Although the deposits are mostly oxidised and devoid of pollen, one sample from near the base of the fossiliferous section was shown to belong to Zone g of the Ipswichian (Last) Interglacial. As the bulk of the brickearth is contained between this and gravels disturbed by cryoturbation above the brickearth, the deposit must represent aggradation in a river valley in the second half of the Ipswichian Interglacial.

The Non-marine Mollusca of the Cainscross Terrace near Stroud, Gloucestershire

AbstractRecent collecting has revealed a typical cold mollusc fauna in the Cainscross Terrace of the Frome valley near Stroud. Cold conditions are also indicated by lithology and vertebrates. The most likely date seems to be the Irish Sea Glaciation, i.e. the main phase of the Last Glaciation.

NON-MARINE MOLLUSCA FROM THE ESTUARINE CLAYS (HOLOCENE) OF NORTH-EAST IRELAND

Journal Article NON-MARINE MOLLUSCA FROM THE ESTUARINE CLAYS (HOLOCENE) OF NORTH-EAST IRELAND Get access NORA F. MCMILLAN NORA F. MCMILLAN Search for other works by this author on: Oxford Academic Google Scholar Journal of Molluscan Studies, Volume 34, Issue 5, August 1961, Pages 296–298, https://doi.org/10.1093/oxfordjournals.mollus.a064873 Published: 01 August 1961 Article history Received: 13 January 1961 Published: 01 August 1961

Non-Marine Mollusca From the Florida Islands, Solomon Islands

Abstract Land and freshwater molluscs collected on Florida and Tulagi Islands by Robert E. Kuntz in 1943–1945 are reviewed. New species are Mocella kuntzi, Orpiella kuntzi, Palaina floridana, Palaina clappi, and Palaina megamorpha. Several other species are reported from the Solomons for the first time.

Appendix. Non-marine Mollusca from Aby

The following Mollusca, mostly in a bad state of preservation, were recovered from samples from Aby (localityF) : 258-264 cm 264-285 cmPisidium casertanum(Poli) 18 —P. subtruncatmn Malm15 —P. nitidum Jenyns— 2 Some of the specimens ofP. casertanumapproach var.ponderosaStelfox, but it is impossible to draw a division between them and normalP.casertanum.From the clay immediately above the boulder clay in trenchKthe following were obtained :Lymnaea sp.,3;Planorbis?laevisAlder, 1 ;Planorbis crista(Linné), 1 ;Pisidium subtruncatumMalm, 1 ;Pisidium nitidumJenyns, 7. All the species from Aby are freshwater; all are tolerant of a wide range of climatic and ecological conditions. They consist of hardy elements of the present British fauna such as might be expected to survive the cold conditions indicated by the pollen.

An interglacial tufa near Hitchin Hertfordshire

A Pleistocene tufa or travertine containing a remarkable fauna of nonmarine Mollusca with strong Central European affinities is described. Three species are recorded as new to this country, comprising the extinct Acicula diluviana Hocker, and forms of Graciliaria (Ruthenica) and Laminifera (Neniatlanta), members of the Clausiliidae hitherto unknown in North-West Europe. An extinct badger ( Meles) is also present, together with a small microtine fauna of somewhat archaic type. The stratigraphy of the deposits is described and their relation to the local glacial drifts discussed; the evidence suggests that the tufa belongs within the Hoxnian (Great) Interglacial.

The non-marine mollusca of the interglacial deposits at Bobbitshole, Ipswich

The non-marine Mollusca from the Eemian (Last) Interglacial deposits at Bobbitshole, Ipswich, are analyzed. The fauna is a local one of marsh and fresh-water species and contains very few species which appear to have been washed in from other environments. The more common Mollusca are arranged into groups of climatically tolerant, less tolerant and least tolerant species, and the percentage frequency of both species and groups is analyzed through the deposit. Tolerant species dominate in the lower part of the deposit, while the less and least tolerant groups become successively important higher up. A puzzling secondary maximum of tolerant species near the top of the deposit is discussed. The conclusions about local and climatic conditions reached from the Mollusca agree closely with those derived from the plants. It is concluded that the relative abundance of the different species of Mollusca, rather than the presence or absence of isolated specimens of certain species, is important in deducing the conditions under which they lived.

VII.—Mollusca Orcadensia

SynopsisThis paper brings together from all available sources records of marine mollusca indigenous to Orkney, together with notes on their local distribution. Besides incorporating the results of recent research it includes a brief account of work done in the islands by earlier conchologists. For convenience of reference the list of species follows the nomenclature and systematic arrangement used by the Conchological Society of Great Britain and Ireland in Winckworth's revised list of the British Marine Mollusca. The small section on local collecting grounds may prove useful to future workers. A commentary seeks to relate the molluscan fauna of the islands to a wider context of distribution and draws attention to the seemingly characteristic western influence present in Orkney waters. A brief note is added on the non-marine mollusca of the islands.

Anatomy of Biomphalaria Boissyi as Related to Its Infection with Schistosoma Mansoni

Among the fresh-water mollusks, planorbid snails play a significant role in the life histories of digenetic trematodes of man and livestock. Investigations of their morphology are of considerable value to both the malacologist and the parasitologist. Wright (1952) emphasized the need for studlies of internal anatomy as an aid in the identification of snail vectors of bilharziasis. Although Baker (1945) presented a most comprehensive account of planorbids, the scope of his work was so broad that phases of studies pertaining to some genera and species, such as Biomphalaria boissyi, were not taken into account. Biomphalaria was considered only in a very abbreviated way and, because of a lack of specimens, no morphological details were included. Somewhat earlier, Connolly (1925) in his discussion of the non-marine mollusca of Portuguese East Africa referred to the anatomy of Planorbis pfeifferi., which he later (1938) regarded as, Biomphalaria pfeifferi. The purpose of this paper is to consider the anatomy of the planorbid snail, Biomphalaria boissyi, the intermediate host of Schistosoma mansoni and other trematodes in Egypt, the Sudan, and other African countries. This study also illustrates the general organization of a planorbid snail. Oine objective is to provide the malacologist and the parasitologist with descriptive morphological information and as many anatomical illustrations as possible. Emphasis is placed on the position of the internal organs and their relation to one another. Particular stress is placed on anatomical information in relation to infection of B. boissyi with S. mansoni, and its bearing on snailparasite relations in general. Similar investigations were carried out by Faust and Hoffman (1934) in their studies of schistosomiasis in Puerto Rico. The systematics of the genus Biomphalaria was considered recently in an extensive study by Amberson and Schwarz (1953). They stated that the snail intermtediate host of S. mansoni in Africa is Biomphalaria alexandrina. Two subspecies were recognized: B. a. alexandrina Ehrenberg, with a northern distribution and B. a. pfeifferi Krauss with a southern distribution. However, their conclusions were based on shell characters and biological factors; they contributed no anatomical data. It is becoming increasingly evident that only after the anatomical details have beeni clarified that one could appreciate whether Biomphalaria boissyi (Potiez et Michaud, 1838) should be synonymized with B. alexandria (Ehrenberg).2

The Clacton (Essex) Channel Deposits

Summary New field evidence of the Clacton channel deposits i3 recorded. A general revision of the non-marine mollusca by the late A. S. Kennard and Mr. C. P. Castell points to the same invasion of Rhenish species that Kennard found in the middle of the Swanscombe sequence. The marine mollusca of the estuarine stage include nothing to distinguish them from the Holocene, although the rest of the biotope points to the mid-Pleistocene. The erratic rocks are traced back by Mr. D. F. W. Baden-Powell to a stream of proto-Thames material from the west passing through mid-Essex to the gravel cliffs at Holland-on-Sea and Clacton. A few remains of Microtinae have been examined by Mr. M. A. C. Hinton and these tentatively suggest close comparison with Grays. The mammalian remains are not described in detail, but the finding of the remains of the food of Rhinoceros in the crevices of the molars is recorded. The Clacton Stage is associated closely with the Early Taplow brickearth of Grays-Thurrock, and equally with the middle part of the Swanscombe sequence.