ALBERT

Description: Young tests studied in very thin sections with the light-microscope with a magnification x 1000 showed, that the results obtained hy Reiss, Be Hemleben and others cannot be true. A primary membrane with sieve-plates where pores are projected by the animal is the first formed membrane; then a hyaline layer is formed beneath the membrane with a general thickness of 2-5 (1 in the Globigerine species. Hie thickness of this primary lamella is also that of the lamella covering the proloculus and the first initial chambers and their septa which always have simple walls. In this primary lamella the pores are spared out and they are at first closed by the sieveplates which, however, may be dissolved soon but for a rim in the wall of the pores. Then a second layer Starts, now at the outside of the primary membrane, beginning with fine knobs between the pores but soon forming a whole layer of clear calcäreous matter. It is in this stage that also the first spines are formed, strengthened at their bases by a mount of calcareous matter; so these spines end at their bases at the primary membrane. The thickening of the outer lamella may continue; this lamella is formed soon after the building of the primary lamella, Not only by means of the study of the last formed chamber of several species of Globigerines this result was obtained, but also by means of the colouring of the layers in Globigerina rubra. It is shown, moreover, that Sphaeroidinella dehiscens cannot be an advanced stage of Globigerina triloba. In Globorotaliid species the primary lamella, as found by Reiss c.s., mostly is slightly thicker than in Globigerines. In this group young specimens were observed with last formed chambers having only the primary lamella covered by the primary membrane also, whereas specimens were found which have septa only built by this lamella. The second, outer lamella is formed soon after the primary lamella, so that many specimens occur which show two lamellae in the wall of the last formed chamber. The result is thus quite similar to that obtained in the Globigerines: the species around Globorotalia are monolamellar too.

Description: Four marine Cretaceous samples collected from the Agulhas Bank are discussed and their ostracodal assemblages described. Two of the samples are considered to be Lower Cretaceous, and the others Lower-Middle Senonian and Maastrichtian in age. Two new genera, twelve new species, and one new subspecies are described. Details of the foraminiferal assemblages are also given.

Description: The planktonic foraminiferal fauna was studied in 104 surface plankton samples collected by the author during the crossing in both directions of Drake Passage between Tierra del Fuego and Elephant Island off the Palmer Peninsula, Antarctica, during the months of January and February, 1969. Samples were gathered by means of a fire pump. This method is discussed and recommended for planktonic foraminiferal collection. Eight species were determined, and their horizontal distribution was established. The percentage abundance of each species, as well as the number of specimens per cubic meter of filtered water, were calculated for every station. Distribution patterns of foraminifers were compared with those obtained by previous authors and were related to the surface hydrology. Some discrepancies were found and discussed. The most simple means of separating Globigerina pachyderma from G. quinqueloba is proposed and the most simple means of locating the Antarctic Convergence by the use of foraminifers is discussed. Abnormal spinosity of foraminiferal tests is considered.

Description: Mature thalli of Fucus distichus, F. edentatus, F. serratus, and F. vesiculosus were obtained in unialgal culture from zygotes and were grown in an enriched seawater medium. The two former species were maintained in culture for more than 2 years, in which time the length of thalli of F. edentatus never exceeded 4 cm. The other species grew reasonably well with a maximum rate of elongation of about 1 cm per month for F. serratus. In all species the rates of growth were less than that observed in nature. Fertile receptacles with viable gametes were formed in F. distichus, but the other species never attained reproductive maturity. All specimens retained their characteristic morphology under identical conditions of culture, and it is suggested that morphological variation amongst Fucus spp. is due mainly to hybridization rather than to environmental conditions. There was no indication that any of these species required intertidal conditions, and no unique nutritional requirements were identified.