ALBERT

Description: Three species of Foraminifera, which were ususally regarded as members of the Ammonia beccarii (L.)-group or closely related, are investigated. The material comes mainly from the lagoon of Cochin and from the shelf off Cochin (SW-India), Malabarcoast). Sections and Stereoscan-microphotographs revealed considerable differences in the internal structure (double or simple septae, different shape of the tooth-plates, areal or interiomarginal situation of the septal apertures). This leads to the conclusion, that only one species (Rotalia beccarii var. sobrina SHUPACK 1934) is a true Ammonia. Rotalia beccarii var. tepida CUSHMAN 1926 should be put to the genus Discorbis, Rotalia pauciloculata PHLEGER & PARKER 1951 is regarded as a species of Pseudoeponides. Some ecological observations are added.

Description: A new method is proposed for determining absolute surface water paleotemperatures by means of Globigerina bulloides d’Orbigny. This method is based on the relationship between the percentage of sinistral specimens in a population of the species mentioned and the temperature of the water. The advantages and disadvantages of the method proposed are discussed.

Description: Eighty-seven specimens of Bathothauma lyromma from the ‘Discovery’ collections have provided new information on this unusual species. The size range represented is sufficient to trace the development from small larvae to near adult. Information on sexual development is also given. Twenty-nine specimens from opening-closing nets show that Bathothauma occupies the depth range 100–1250 m, with smaller specimens living at shallower depths than the larger ones.

Description: A female blue-ringed octopus, Hapalochlaena sp. (probably lunulata), was maintained in an aqarium for nearly 3 months, during which time it spawned and cared for the eggs until hatching. The young are planktonic. Embryonic development does not differ markedly from that observed in other octopods, uniting certain features of the development of Octopus vulgaris and Eledone cirrosa. In terms of reproductive biology and development, the species differs from the lesser blue-ringed octopus Hapalochlaena maculosa in its mode of spawning, egg size and mode of life of its young. These differences correspond to conditions recorded for Octopus spp. and Eledone spp.

Description: Shipworms or Teredinidae may be dispersed either as adults in floating wooden objects or as pelagic larvae drifting near the sea surface. Five shipworm species, i.e., half of those having an amphi-Atlantic geographical distribution, are known also to have pelagic phytoplanktotrophic larvae which can be carried by ocean currents. From a series of 742 plankton samples taken from throughout the temperate and tropical North Atlantic Ocean, it can be shown that shipworm larvae are not uncommon in the open sea. Teredinid veligers were found in 19% of all samples taken. One species of larvae, identical in all details to that described by Rancurel (1965), is particularly prevalent and is tentatively identified as Teredora malleolus (Turton). A definitive identification will be possible only after the pelagic larvae of the other Atlantic species are known. The larvae of Teredora malleolus are found throughout the North Atlantic Gyre and the adjacent temperate and tropical seas, and from scattered records in the South Equatorial Current. Larvae of other unidentified Teredinidae species were also found. The distance that larvae may be transported depends upon the length of pelagic larval development and the velocity of the currents. From the known current velocities it can be shown that, even in a few weeks, larvae may be dispersed many hundreds of kilometers. The geographical distribution of shipworm larvae suggests that they are carried along the coasts of continents and even across ocean basins, and that this dispersal must be an important factor in the geographical distribution of the adult forms and in the maintenance of genetic continuity between populations otherwise isolated from one another.

Description: A total of 618 cephalopods comprising 29 identified species and 98 young unidentified larvae were collected at 30° N 23° W in opening–closing rectangular midwater trawls (RMT combination net), an Isaacs Kidd midwater trawl equipped with an openingclosing bucket and a British Columbia midwater trawl. Discrete horizons were fished between the surface and 2000 m and day and night vertical distribution for the more common species is described. Material is sufficiently abundant to draw tentative conclusions on the vertical distributions of 16 species. These show a wide variety of migratory and non-migratory behaviour including diel migration, ontogenetic migration and static distribution at various depths and over various depth ranges.

Description: During 1968 about 7500 km of new magnetic data were recorded by the USNS J. W. Gibbs between the Canary and Cape Verde islands, from the continental shelf to approximately 30øW. These data, together with an equal amount of data from other sources, reveal major magnetic features. The magnetic boundary between relatively undisturbed and disturbed magnetic zones is delineated near the middle of the northwest African continental rise. A sequence of linear north-south-trending anomalies immediately seaward of the magnetic boundary comprise a band about 300 km wide and can be correlated from about 15øN at the Cape Verde Islands to about 26øN just south of the Canary Islands. The band of magnetic anomalies appears to have a right lateral offset of about 100 km near 25øN where intersected by a west-northwest-trending fault near the eastward projection of the Atlantis fracture zone from the mid-Atlantic ridge. At least one prominent positive magnetic anomaly is associated with the northwest. African continental shelf. The magnetic disturbance boundary and the associated band of linear magnetic anomalies are nearly mirror images of similar anomalies associated with the continental margin off eastern North America. Major features of the magnetic-field-strength anomalies in the North Atlantic are highintensity anomalies associated with the continental terrace (shelf plus slope), a magnetic quiet zone, a magnetic boundary, and a sequence of characteristic anomalies associated with the