Distribution and Migrations of two Cerithid Snails on a Sand Flat in Bermuda

Abstract. Two species of cerithid prosobranchs live on a sand flat in Bermuda. At low tide during day light Batillaria minima is found on the surface whereas Cerithium lutosum remains buried in the sediment. This correlates with much higher lethal and coma temperatures, as well as much greater resistance to desiccation, of the former species. However, at other diurnal or tidal stages the two species co-occur in the same layer of sand. Despite greater resistance to physical factors the population of B. minima seems to be declining since in 1980 juveniles of this species were rare on Tuckers Town Flat whereas the population of C. lutosum was thriving.     

On seismic activity

Summary Seismic activity at a point of the surface of the earth up to a given time has to be computed by the total energy per unit area at the point considered in consequence of the earthquakes up to that time. The definition of seismic activity of a region can be developed from that. Seismic activity in a given time-interval results from earthquakes up to the upper limit of that interval. In consequence of a suitable valuation seismic activity is always convergent. For sufficiently large time-intervals a formal relationship between seismic activity and seismicity can be constructed.Publication No. 27 of the Institut für Geodynamik, 69 Jena (GDR), Burgweg 11. Forschungsgemeinschaft der Deutschen Akademie der Wissenschaften zu Berlin.     

Zur Geomorphologie Südchinas

Ohne Zusammenfassung     

IV. Stratigraphie Die fazielle Einstufung fossilführender Sedimente

Ohne Zusammenfassung