New discoveries have established the presence of nine ammonite zones in the Middle Jurassic beds of East Greenland. The top two are Lower Callovian; the remaining seven yield ammonites unknown from extra-Boreal provinces and are presumed to range down through the Bathonian, possibly into the Bajocian.

Abstract. The forces governing marine circulation of a meridional transcontinental seaway is explored with the Princeton Ocean Model. The Jurassic Laurasian Seaway, which connected the low-latitude Tethys Ocean with the Arctic Sea is modeled quantitatively. The global ocean is found to have a profound influence on seaway dynamics. A north-south density difference and hence sea level difference of the global ocean was probably the main factor in forcing the seaway flow. When the Tethys waters were the denser water, the net seaway flow was southward, and conversely, it was northward for denser Arctic waters. Marine bioprovincial boundaries and sediment data indicate that the seaway probably was dominated by Boreal faunal groups and reduced salinities several times in the Jurassic. The model results suggest that this can be explained by southward flowing seaway currents, which may have been related to an oceanic thermohaline circulation where no northern high-latitude deep convection occurred.

New ammonite finds indicate that the sea transgressed over the crystalline basement of Milne Land, East Greenland, in Boreal Bathonian time and not in Middle Oxfordian as previously thought. A coral (Enallocoenia callomoni Beauvais) occurring in the transgressive Upper Bathonian deposits is the first hermatypic coral known from the Boreal Middle Jurassic. The unusually complete Boreal Upper Callovian-Oxfordian-Kimmeridgian ammonite succession is described; the faunas include remarkable occurrences of submediterranean genera (Hibolithes, Pachypictonia, Streblites). Finally, the sedimentary and tectonic evolution of Milne Land and adjacent areas in Jurassic time is outlined. It is shown that the area was characterized by gentle block-faulting.

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Eight clusters of small spherical and subspherical objects, some isolated and some associated with shells of perisphinctid ammonites, have been recovered from the Lower and Upper Kimmeridge Clay (Upper Jurassic) of the Dorset coast, England. They have been interpreted as ammonite egg sacs and represent the freshest and best‐preserved examples known so far. Their structures and the ecological framework in which they occur are discussed. The parents are thought to be members of the two eudemic genera Aulacostephanus and Pectinatites that dominate the biostratigraphy of the ammonites in the range of the Kimmeridge Clay in which they occur. Isolated nuclei of ammonitellae have also been recovered.