ALBERT

Description: This article reviews the major findings of an intensive geological and geophysical study of the Brazilian margin and adjacent oceanic and continental areas. Most of the data fits well with standard plate models for Atlantic-type margins, with clearly recognizeable pre-rift, rift, proto-oceanic and oceanic stages. However there are significant problems regarding the nature of the crust beneath the margin and the position of the boundary between oceanic and continental crust.

Description: This study is based on a collection of Cephalopoda, belonging to the Zoological Museum, University of Copenhagen (Denmark), which Dr. J . Knudsen kindly entrusted to me. Most of the specimens were collected on the West African coast by different expeditions: "Dr. Th. Mortensen's Java-South Africa Expedition 1929-1930", the "Atlantide Expedition 1945-1946", "Dr. G. Thorson's Expedition to the Canary Islands 1947", and the "Galathea Expedition 1950-1952". Some other specimens from the West African coast or from other localities were added.

Description: Males of Eledone cirrhosa grow to a size little over 600 g and normally have well-developed, and presumably active, reproductive organs from about 200 g upwards. Total weight of the genital bag is well correlated with total body weight (r= 0·906). Growth of the testis precedes that of the spermatophoric sac, and the size of neither of these reproductive components is predictable from body weight. The sizes of these organs and the estimated number and length of stored spermatophores are given for 100 g intervals of total body weight. No evidence was obtained for a seasonal trend in male maturity.

Description: Secondary minerals found in fracture fillings and in fragments of altered basalt from Holes 417A and 417D were studied by both X-ray diffraction and chemical techniques. Minerals found in fracture fillings from Hole 417A are dominated by montmorillonite, "protoceládonite," analcite, and lesser saponite; celadonite and ferrosaponite are the characteristic secondary minerals in Hole 417D fracture fillings. Assuming that minerals found in such fracture fillings reflect the composition of the secondary fluids that produced them, it is apparent that those from Hole 417A were dominantly Al-rich, while those from Hole 417D were more enriched in Fe, Mg, and K. X-ray diffraction study of bulk samples support such fundamental differences in secondary mineralogy. In addition, the X-ray data on bulk samples suggest that primary plagioclase is the feldspar in Hole 417D rocks, and secondary potassium feldspar is the feldspar in Hole 417A altered rocks. Using available published data on secondary miner?1" found in other altered oceanic crust, it is possible to interpret the differences in secondary mineralogy that exist between the two sites. Secondary minerals present in Hole 417D rocks are believed to have formed under hydrothermally influenced, low temperature, nonoxidative diagenesis; whereas, those present in Hole 417A were produced under similarly low temperatures, but much more highly oxidizing conditions. The fundamental differences in secondary mineralogy between the two sites can be best explained by the accompanying remobilization of elements that involved plagioclase alteration in Hole 417A rocks. A comparison of the composition of Hole 417A and 417D secondary minerals with those found in younger crust suggests that the age of crust, influenced by the changing conditions of alteration, control the chemistry of secondary minerals found in available pore spaces in altered rocks. Minerals found in young crust (〈15 m.y.B.P.) are highly Mg-rich; minerals found in crust of intermediate age (—15-50 m.y.B.P.) are dominantly enriched in Fe and Mg; and those found in older crust have higher contents of Al and K.

Description: The following report is a synthesis of the main results of the OECD Cooperative Programme on Eutrophication. It is the outcome of several years' concerted effort by 18 Member countries. The objectives were to establish, through international cooperation, a basis for eutrophication control of inland waters (lakes and reservoirs in particular), and to develop better guidelines for fixing nutrient load criteria compatible with water use objectives. The present report is both complementary and supplementary to the four Regional Project Reports (2) already published. In parallel with the OECD study programme, progress has been made in other areas, particularly in dynamic modelling. The results of the OECD study and approach have already been successfully applied in several instances in North America, Europe and elsewhere. It can be anticipated that 0- while knowledge of eutrophication and its control methods are advancing -- the OECD results presented here will continue to provide a basic reference in eutrophication control studies.

Description: The reproductive ecology of three sympatric hermit crab species from the Bay of Panama is examined. All three species reveal patterns of size and reproduction mediated by their supply of shells. Shells are demonstrated to be in limited supply. Crabs with shells large enough to allow growth, put effort into growth at the expense of reducing reproductive expenditures, while crabs in shells too small to permit growth allocate more time and effort into immediate reproductive gains. This resource regulated trade-off between growth and reproduction gives these tropical crabs plasticity in important life-history traits. Crabs with a relatively poor supply of shells reproduce at smaller sizes, reproduce more frequently, have larger clutches, and are unable to reach the larger sizes of crabs with a less limiting supply of shells. This flexibility in life-history traits allows these crabs to tailor their reproductive schedules to resource supplies controlled by gastropod mortality, as well as the presence of competitors and predators.

Description: The interaction between thrust and strike slip fault systems is well detailed in Pakistan where the Chaman transform zone connects the Makran and Himalayan convergence zones and contains an internal convergence zone in the Zhob district. The transform zone contains numerous strike slip faults of which the Chaman fault proper is the westernmost. We can demonstrate at least 200 km of left lateral displacement along the Chaman fault alone. In the Zhob belt N-S shortening by folds and a major thrust fault amounts to several dozen kilometres. The 400 km wide Makran convergence zone is now being shortened by E-W oriented folds, thrust faults, and reverse faults. As these faults in the Makran zone approach the transform zone, their traces bend to the N and motion on each of them becomes oblique, combining reverse and left lateral slip. They merge continuously with the strike slip faults of the Chaman transform zone. The Makran thrust system and the Chaman transform zone first became active in the late Oligocene or early Miocene. Later (Pliocene?), a component of left lateral shear occurred across the entire Makran Zone in association with the opening of the newly identified Haman-i-Mashkel fault trough S of the Chagai Hills and W of the Ras Koh. The total displacement and displacement rate across the Chaman transform zone varies in response to the rates of convergence in the plates E and W of the zone.

Description: Many of the difficulties of staining plastic embedded tissues for light and electron microscopy derive from physical exclusion of hydrophilic staining reagents by hydrophobic embedding media. Structures which stain most intensely with hydrophilic reagents usually contain less hydrophobic plastic than do non-staining structures. Such incomplete infiltration is apparently caused by exclusion of viscous, hydrophobic monomers by physically dense and/or well hydrated tissue elements. In keeping with this, generalized staining of tissues embedded in hydrophobic media does occur when hydrophobic reagents are used. Staining of plastic-free structures with single hydrophilic reagents or with sequences of such reagents, is, however, largely rate-controlled. The surprising similarity of hydrophilic and hydrophobic plastic embedding media is discussed. Limits of this simple model are explored, with a consideration of the roles of fixative and of monomer-tissue reactions

Description: Les données géologiques et géophysiques recueillies dans le golfe de Gascogne depuis 12 ans ont été partiellement réinterprétées d'après les forages IPOD du leg 48, et une nouvelle carte structurale en couleurs a été établie〈1〉. Cette carte montre la profondeur et l'extension du socle océanique et de la croûte continentale, amincie par les phases de distension mésozoïques et/ou épaissie par les phases de compression cénozoïques. Les structures sont classées d'après leur âge et leur nature: failles normales et décrochantes, témoins du « rifting » des marges armoricaine et aquitaine du Néocomien à l'Aptien; failles transformantes de la plaine abyssale, contemporaine de l'ouverture océanique de golfe à l' Albien et au Crétacé supérieur jusqu'au Santonien ; chevauchements, failles inverses, prismes d'accrétion tectonique, décrochements,failles normales et horsts créés par la subduction de la plaque européenne sous l'Ibérie du Maestrichtien (?) à l'Éocène moyen; enfin, structures tardives dues au rejeu à l'Oligocène ou au Miocène des accidents tectoniques antérieurs. Ces données structurales sont compatibles avec un modèle cinématique selon lequel l'Ibérie a subi, par rapport à l'Europe stable, au moins trois rotations successives depuis le Jurassique: déplacement en direction du sud-ouest au Crétacé inférieur jusqu'à l' Aptien supérieur; divergence et mouvement vers le sud-est de l' Aptien terminal au Santonien ; enfin, convergence et mouvement en direction du nord-ouest au Paléocène et à l'Éocène inférieur. IPOD drillings on the armorican margin allow to review geological and geophysical data collected in the Bay of Biscay for the past twelve years. They also allow to draw up a new structural sketch. The sketch displays the depth and extension of oceanic and continental basement. Structures fall into four catégories: 1) Neocomian-Aptian normal and associated probable strike-slip faults, related to the rifting of the armorican margin; 2) Albian-Santonian transform faults within the oceanic basement, resulting from the iberian rotation and correlative opening of the Bay of Biscay; 3) Maestrichtian(?)-middle Eocene thrusting, reverse faults, strike-slip faults, accretionary tectonic prism and normal faults linked to the subduction of the european plate beneath the north-spanish margin emphasised by a fossil marginal trench and a bulging of the deeping plate; and 4) Oligocene-Miocene reverse, normal and strike-slip faults. The structural data agree with a three phases kinematic model: a) Néocomian-Aptian NE-SW motion of the iberian plate with respect to the stable Europe (rifting); b) AlbianSantonian NW-SE drifting of lberia (and related oceanic accretion within the Bay); c) Paleocene-lower Eocene SE-NW converjence resulting in subduction of the european plate beneath the Iberian plate and subsequent shortening and thickening of the north-spanish margin.

Description: Foraging rate was highly variable among shore crabs of the same size category and for individual crabs from day to day. Possible physiological reasons for this variability are discussed. Shore crab foraging rate, both in terms of mussels eaten per day and energy intake per day, was estimated to be higher at 17°C than at 10°C. The shape of diet curves and their mode for male shore crabs at 17°C closely resembled those for 10°C, indicating that the temperature increase had no effect on their previously demonstrated optimal foraging strategy. Female and certain male shore crabs showed a preference for prey smaller than for other equivalent sized males. These suboptimally feeding male and female crabs attained a relatively higher prédation rate (mussels day‐1), although their energy intake (KJ day‐1) remained lower than that of optimally feeding males. Preferred mussel size, number of mussels eaten per day and energy intake were strongly related to master chela height. The diet curves for female and suboptimally feeding male shore crabs could be explained by these crabs’ proportionately smaller master chelae.

Description: Sonic transmitters coupled to depth-sensitive strain gauges and attached to shells of Nautilus belauensis in Palau, Western Caroline Islands, established net vertical movement between 85 and 467 m, and lateral movement of about 3km over a period of 7 days and nights. Generally, the animals were found in deep water during daytime and moved to shallower water at night.

Description: The rate of reaction of OH with CS2 to form OCS by reaction (1) has been measured through observation of O14CS following 254 nm equation image photolysis of mixtures of H2O2 with 14CS2. The OH concentrations have been monitored through simultaneous measurement in the same cell of either (a) the oxidation of CO to CO2, or (b) the removal of a hydrocarbon such as C3H8 or iso-C4H10. The upper limit for the formation of OCS based on (a) corresponds to a rate constant k1 〈 0.3 × 10−14 cm³ molecule−1 sec−1. Other chemical reactions in the system have led to the formation of both 14CO and 14CO2, indicating the existence of a complex combination of reactions such that the observed O14CS need not have been formed by (1). The rate of reaction (1) is sufficiently slow that it is neither an important atmospheric sink for CS2 nor an important source for atmospheric OCS. The reaction of OH with OCS has not been measured in these experiments, but by analogy with k1 it is probably not an important atmospheric sink for OCS nor an important source of SO2.

Description: Samples collected at hourly intervals on May 18–19, 1980, at three sites 200 km downwind from Mount St. Helens, have made possible a detailed reconstruction of the conditions that contribute to the compositional heterogeneity of mineral and glass components observed in distal tephra layers. The air fall tephra deposited at the sites during the first 7 hours of the May 18 eruption is mostly coarse grained, microlite-rich, nonjuvenile glass and feldspar. Grain-size maxima in this initial tephra can be related to the cataclysmic blast at 0832 and a subsequent pulse of the eruption at 1200. Juvenile, microlite-free glass increases in relative abundance at the sampling sites beginning at about 1900. Such a change between nonjuvenile and juvenile tephra can be related to a 5-km increase in column height associated with the last major pulse of the eruption which occurred at 1700 at the volcano. Electron microprobe study of both microlite-rich and microlite-free pumice in the time series samples reveals significant compositional differences. Interstitial glass in nonjuvenile pumice deposited during the first few hours at the sampling sites is enriched in SiO2 and K2O and depleted in TiO2, FeO*, and MgO relative to juvenile glass. By comparison, major element composition of the least evolved juvenile glass sampled during the last several hours of the eruption displays a slight trend toward less evolved composition. Least squares calculations suggest that the more evolved character of the nonjuvenile glass can be explained by greater fractional crystallization brought about by enhanced cooling in a cryptodome prior to eruption, whereas the temporal changes observed in juvenile glass composition during the last several hours of the eruption suggest the presence of a small, slightly zoned magma chamber at depth. Electron microprobe study of glass-coated ilmenites, magnetites, and plagioclases provides the following estimates of the physical conditions in this reservoir: 865°±50°C, PH2O = 2.2 kbar and -log ƒO2 = 11.7. Analyses of bulk pumice, glass and selected mineral phases from May 25, June 12, July 22, and October 16–18 pumices erupted from Mount St. Helens indicate that the bulk pumice (magma) compositions have become slightly more andesitic with time, while mineral and co-existing glass compositions have changed significantly in post-May 18 eruptions with both being more highly evolved than those associated with the May 18 eruption. An application of the magnetite-ilmenite geothermometer to June 12 and July 22 samples indicates temperatures of 919°±30°C and 930°±50°C, respectively. Least squares calculations suggest that such evolved post-May 18 glass and mineral phases can be derived by fractional crystallization of a magma composition like bulk May 18 pumice into approximately 50% crystals and 50% residual liquid. Such partitioning between crystals and residual liquid appears to have occurred on the scale of centimeters and is interpreted as a consequence of accelerated crystallization under reduced water pressure.

Description: We present chemical data on magmatically heterogeneous pyroclastic deposits of late Quaternary age erupted from zoned magma systems underlying Tenerife (Canary Islands), Sao Miguel and Faial (Azores), and Vesuvius. The most fractionated magmas present at each centre are respectively Na-rich phonolite, trachyte, and K-rich phonolite. Within any one deposit, chemical variation is either accompanied by changes in the phenocryst assemblage (petrographic zonation) or is largely manifested in trace element abundances, unaccompanied by any petrographic change (occult zonation). Zoning is analogous to that in calc-alkaline systems where the most fractionated products are high-silica rhyolites. When a range of magma types are considered, a correlation emerges between roofward depletion of trace elements (especially REE) in the zoned system and compatability of those same trace elements in the accessory phenocryst phases present. Thus, allanite- or chevkinite-bearing rhyolitic systems are light-REE depleted roofwards, the sphene-bearing Tenerife system is middle-REE depleted roofwards, the melanite-bearing Vesuvius system is heavy-REE depleted roofwards, while the Azores systems, which lack these phases, display roofward REE enrichment. Therefore, the behaviour of trace elements may in each case be explained by fractionation of observed phenocryst assemblages. The resemblance between features of zoned magma systems and published work on the dynamic consequences of cooling saturated aqueous solutions prompts us to suggest that sidewall crystallization and consequent boundary-layer uprise to form a capping layer at top of the system may be a plausible mechanism for the generation of both petrographic and occult zonation. Reverse zoning occurs among the first-erupted tephra of some deposits, demonstrating that the most highly differentiated magma available is not always the first to be tapped during an eruption from a zoned system.

Description: The widespread occurrence of organic-carbon-rich strata (‘black shales’) in certain portions of Jurassic, Cretaceous and Cenozoic sequences has been well-documented from Deep Sea Drilling Project sites in the Atlantic and Pacific Oceans and from sequences, now exposed on land, originally deposited in the Tethyan ocean. These ancient black shales usually have been explained by analogy with examples of modern deep-sea sediments in which organic matter locally is preserved by (1) increasing the supply of organic matter, (2) increasing the rate of sedimentation, and/or (3) decreasing the oxygen content of the bottom water. However, detailed examination of many black shales reveals characteristics that cannot be explained by simple local models, including: their approximate coincidence in time globally; their occurrence in a variety of different environments, including open oxygenated oceans, restricted basins, deep and shallow water; their interbedding with organic-carbonpoor strata which often dominate a so-called black shale sequence; their deposition by pelagic, hemipelagic, turbiditic and other processes; and the variations in type and amount of organic matter that occur even within the same sequence. A more complex model for the origin of black shales therefore appears most appropriate, in which the cyclic preservation of organic matter depends on the interplay of the three main variables, namely supply of organic matter, sedimentation rate, and deep-water oxygenation, each of which varies independently to some extent. The variation and relative importance of these parameters in individual basins and widespread black shale deposition in general are linked globally and temporally by changes in global sea-level, climate and related changes in oceanic circulation. An important and often overlooked factor for the supply of organic matter to deep-basin sediments is the frequency and magnitude of redepositional processes. The interplay of these variables is discussed in relation to the middle Cretaceous and Cenozoic organic-carbon-rich strata, in particular, which show marked differences in the relative importance of the different variables.

Description: Studies of sexual maturation have been made on a large sample of Eledone cirrhosa from the North Sea off Aberdeen, Scotland. In females the wet weights of the ovary and oviducal glands have been recorded for a wide range of body sizes and related to the total body weight. The length dlstribution of a sample of eggs from each ovary was also measured. Assessed either by ovary enlargement or the mean egg length, female E. cirrhosa become mature at a wide ränge of body size and so state of maturity is not predictable from size of the animal. In males the total weight of genital bag is, by contrast, clearly correlated with body weight although this is not true for testis alone, presumably because of transfer of sperm from testis to spermatophoric sac.

Description: Changes in the relative size of the ovary, oviducal glands and eggs are described for Eledone cirrhosa captured from the North Sea off Aberdeen over a 3 year period (N = 488). The analysis is based only on freshly caught animals, excluding those held in aquarium conditions (〉 5 days). Ovary enlargement and egg size estimates are used as indices of sexual maturity. Between 0–15% and 18–95% of total body weight is contributed by the ovary. Maximum egg length in the ovary ranges up to 7 mm. On these criteria, sexual maturation typically occurs at body sizes between 400–1000 g although some animals of 1000–1200 g are found showing no evidence of ovary enlargement. The majority of the monthly sample is always immature but maturation can apparently occur at almost any time of the year. Increase in mean ovary index and mean values for egg size are strongly seasonal and indicate a peak incidence of sexual maturity over 2–3 months in the July-September period. Spawning is presumed to follow within 1 month. Estimates of the fecundity of the females, based on the egg sample from the ovary, range from 2·2 × 103 to 55 × 10 3 eggs with a mean of 11 × 10 3 and a mode of 7·5 × 10 3 eggs.

Description: Female Eledone cirrhosa held in aquarium conditions for periods of time of five daysand over show relatively enlarged ovary sizes. Values for ovary index considerably exceed thoseof freshly caught animals and the incidence of the final stage of maturity, in which eggs pack the oviducts, is greater. A comparison of maturity indices for fresh and aquarium males was inconclusive. The range of factors associated with aquarium conditions is briefly reviewed and it is concluded that studies of cephalopod reproductive maturation must distinguish fresh and aquarium animals. Introduction External factors effective in inducing sexual maturation in cephalopods have been suggested several times. The influence of the absence of light has been implicated since the experiments of Wells & Wells (1959) showed that blinded Octopus vulgar is matured precociously. An effect of short day length in stimulating the optic glands of Sepia has been found by Defretin & Richard (1967) and Richard (1967) but this is not clearly the case for Octopus (Buckley, 1977). Octopuses kept in aquarium conditions for lengthy periods are said to have larger relative gonad sizes than those fresh from the sea (Wells & Wells, 1975). One of the factors associated with aquarium conditions is often a degree of starvation, and this circumstance alone is held to be a factor in inducing precocious sexual maturation in Eledone (Mangold & Boucher-Rodoni, 1973). In the course of recent studies on the growth and reproduction of Eledone cirrhosa from the North Sea (Boyle & Knobloch, 1982,1983,1984) animals which had remained in aquarium conditions for 5 days or over were separated from the analysis.

Description: The ‘magnetic quiet zone’ in the eastern Gulf of Aden is located between the oceanic crust of Sheba Ridge and the continental crust of Arabia and Somalia, and is separated from both by important structural boundaries. The seaward boundary is marked by the end of the seafloor spreading magnetic anomaly sequence and by a basement depth discontinuity. The landward boundary is marked by escarpments made up of a series of normal faults. These escarpments extend from 2–3 km below sea-level to 1500 m above sea-level and are equivalent of the ‘hinge zone’ found at mature continental margins. The magnetic field in the quiet zone is flat in some areas and in others is characterized by anomalies of up to several hundred gammas which are correlatable over distances of up to about 20 km and which appear related to basement topography. The basement lacks the topographic slope characteristic of mid-ocean ridge flanks and is characterized by moderately rough relief. The crustal structure appears quite heterogeneous and where the crustal thicknesses have been determined, they are slightly greater than those of oceanic crust. New heat flow measurements show high values (95.7–123.3 mW m−2) in the quiet zone with values decreasing from Sheba Ridge toward the coast. The unusual structure of the quiet zone and the observations that more opening appears to have occurred between Arabia and Somalia than can be accounted for by the oceanic crust of Sheba Ridge leads to the suggestion that the magnetic quiet zone was generated by diffuse extension of continental crust through a combination of rotational (listric) faulting and dyke injection. This possibility is investigated using both a ‘stretching’ or ‘lithospheric attenuation’ model and a model in which a portion of the extension occurs through dyke injection. It is found that these models can adequately match the observed heat flow and basement depths although very large amounts of extension (β=4–6) are required in the deep seaward portion of the quiet zone. This results in more extension than is compatible with the documented motion between Arabia and Africa. However, formation of the magnetic quiet zone occurred over a period of 10–15 Myr rather than instantaneously as assumed in the simple models. When the effects of a finite length rifting episode are considered, less extension is required and the observed geophysical data are consistent with a diffuse extension origin for the magnetic quiet zone.

Description: Gut content analyses have shown that the diet of the long-finned squid, Loligo pealei, differs between inshore spawning and nursery grounds and offshore winter grounds. In this study, squid were collected inshore from May through November in lower Narragansett Bay, Rhode Island and offshore during winter along the continental shelf between Cape Hatteras and Cap Cod. In both collections crustaceans were more frequently consumed than either fish or squid, but fish were eaten by a wider size range of squid and more frequently inshore. Prey-type selection based on size was common in both samples, but it is unlikely that the species composition is the same in both areas. These data suggest that L. pealei is a highly opportunistic predator, whose diet primarily reflects the local abundance of potential prey species. Such a flexible feeding strategy could account for the large spatial and temporal variations which have been reported in the diet of this squid from various offshore areas.

Description: Harpoon-like setae from the polychaete scale-worm, Hermione hystrix, were found embedded deeply in the brain of Octopus vulgaris. The setae had passed across the cuticular lining and muscles of the oesophagus before entering the surrounding soft nervous tissues. Further investigation showed that Octopus will eat Hermione, confirming other reports that polychaetes form part of the diet of octopods.

Description: The oldest igneous rocks on Maio are pillow lavas of Mid-Ocean Ridge pillow basalts character which have been tilted and uplifted about 4 km from the ocean floor to outcrop as a partial ring, dipping steeply away from a central plutonic complex made up of pyroxenites, essexites, syenites and carbonatites. The ocean floor volcanic rocks are overlain conformably by a stratigraphically continuous pelagic carbonate succession which demonstrates a shallowing depositional environment from the Upper Jurassic to Upper Cretaceous times, when tuffaceous beds indicate renewed volcanism. The tuffs are associated with rudites demonstrating the emergence of the island and amongst the clasts are plutonics indicating Upper Cretaceous magmatism and the unroofing of the volcano to a substantial depth. Deformation under compressive stress resulted in the folding and local repetition by thrusting of this sedimentary cover, which, together with the plutonic core, had been intensively injected by major sills. The Mesozoic succession has been planed off and overlain with marked unconformity by a largely Neogene sequence of volcanic and terrestrial sedimentary rocks. There is a hiatus throughout the Palaeogene, and constructional activity appears to recommence with ankaramitic hyaloclastite and lava deltas and subaerial ankaramitic flows. These are overlain by fluvial sediments and tuffs. Stratigraphically above these is an extensive plateau of silica-undersaturated lavas, olivine-melilitites and nephelinites, which rest on a planed and locally lateritized surface. At topographically higher levels in the eastern part of the island there are thick ankaramitic lavas and pyroclasts which evidently flowed eastward through valleys cut down into the Mesozoic strata, and appear to be of Pliocene age. The subsequent history of the island appears to be non-volcanic.

Description: Several specimens of the remarkable finned octopod Cirrothauma recently caught are described. The animal is taken at great depths, often near the bottom but sometimes away from it. The enormous arms and web can be spread to give a medusoid form but the animal also swims horizontally mainly using the fins, whose powerful muscles are attached to a large fin support. The animal is gelatinous and perhaps neutrally buoyant, and can almost certainly hover in the medusoid form. The mantle muscles are weak and the funnel very long. The arms are long and have a few small suckers in a single longitudinal row, only some of which have a minute suction chamber. The infundibula are small but the cuticle has small pegs with innumerable pores. The cuticle is closely similar to that of octopods and is capable of adhesion. In the base of each sucker peduncle, male and female, there is a possible light organ. The beaks are large and black, the lower strongly pointed. There is a large tongue with vestiges of a radula. The salivary papilla carries the duct of the `posterior salivary gland' which lies far forward within the buccal complex. The male ducts are simple and produce simple packets of sperms. These are found in the oviducal gland (spermatheca), where the large eggs are fertilized. The heart has an accessory chamber presumably providing extra blood flow to the long arms and large fins. The eyes are small open cups covered by a cornea but with no lens or iris. The rhabdomes are sometimes degenerate. The optic lobe is small with no granular layers of amacrine cells. The suboesophageal lobes are close together and the superior buccal lobe is attached to the brain, as in incirrate octopods. There is a large fin lobe. The peduncle lobe and basal lobes are large, in spite of the small eyes, indicating their importance for locomotion. There are no giant fibres. The supraoesophageal lobes are small, with development only of the tactile region (inferior frontal lobe) and reduction of the superior frontal and vertical lobe system. There are large epistellar bodies but no cranial photosensitive vesicles. The optic gland is clearly of neural origin. The statocysts are very large and typically octopodan with a single macula and one anticrista, but the crista is not subdivided. Cirrothauma, like other cirrates, thus shows some features that are present in Vampyroteuthis, and others that are found in decapods, as well as many present in the octopods without fins. These animals represent in some ways an early condition of the coleoid stock.

Description: The well-known caldera of Thira (Santorini), Greece, was not formed during a single eruption but is composed of two overlapping calderas superimposed upon a complex volcanic field that developed along a NE trending line of vents. Before the Minoan eruption of 1400 B.C., Thira consisted of three Java shields in the northern half of the island and a flooded depression surrounded by tuff deposits in the southern half. Andesitic lavas formed the overlapping shields of the north and were contemporaneous with and, in many places, interbedded with the southern tuff deposits. Although there appears to be little difference between the composition of magmas erupted, differences in eruption style indicate that most of the activity in the northern half of the volcanic field was subaerial, producing lava flows, whereas in the south, eruptions within a flooded depression produced a sequence of mostly phreatomagmatic tuffs. Many of these tuffs are plastered onto the walls of what appears to have been an older caldera, most probably associated with an eruption of rhyodacitic tephra 100,000 years ago. The Minoan eruption of about 1400 B.C. had four distinct phases, each reflecting a different vent geometry and eruption mechanism. The Minoan activity was preceded by minor eruptions of fine ash. (1) The eruption began with a Plinian phase, from subaerial vent(s) located on the easternmost of the lava shields. (2) Vent(s) grew toward the SW into the flooded depression. Subsequent activity deposited large-scale base surge deposits during vent widening by phreatomagmatic activity. (3) The third eruptive phase was also phreatomagmatic and produced 60% of the volume of the Minoan Tuff. This activity was nearly continuous and formed a large featureless tuff ring with poorly defined bedding. This deposit contains 5–40% lithic fragments that are typical of the westernmost lava shield and appears to have been erupted when caldera collapse began. (4) The last phase consisted of eruption of ignimbrites from vent(s) on the eastern shield, not yet involved in collapse. Collapse continued after eruption of the ignimbrites with foundering of the eastern half of the caldera. Total volume of the collapse was about 19 km3, overlapping the older caldera to form the caldera complex visible today. Intracaldera eruptions have formed the Kameni Islands along linear vents concomitant with vents that may have been sources for the Minoan Tuff.

Description: A new species of a monogenean Isancistrum subulatae (Gyrodactylidae) has been discovered on the arms and tentacles of the cephalopod mollusc Alloteuthis subulata at Plymouth and I. loliginis, on the gills of the same host, has been re-discovered for the first time since its original description in 1912. I. subulatae, like other gyrodactylids, is viviparous, and has been shown by experiments to transfer to new hosts by contagion. In nature such transfers probably take place during copulation of the hosts and since the parasite may occur in numbers of several thousands per host, it may thereby constitute a venereal disease.

Description: The feeding biology was investigated of a population of the nordic krill Meganyctiphanes norvegica which inhabits a semi-enclosed deep near the danish island Läsö. The food composition was determined during one year in monthly samples. The analysis of the stomach contents showed a remarkable diversity. Cannibalism is common, Detritus and undigestible matter form a major part of the compounds at all times of the year. The investigation of the feeding appendages gave evidence that the spectrum of food particles fed is determined by the mechanical properties of the fil tering basket. Optical control of the food is not possible because of the insufficient resolution of the eyes. This explanation of the unspecific food requirements was supported by observations on the feeding behavior. The eyes reveal a high sensibility to perceive even very dim light in contrast to their poor resolution of fine details. This feature illustrates the major role of the eyes in the control of vertical migration and orientation. Quantitative aspects of the feeding biology are dealt within the last chapter. The determination of the amount of food contained in the stomachs allowed to quantify the feeding intensity of the nordic krill. A energy budget based on recent findings is presented and its reliability discussed.

Description: The behaviour of Chelophyes has been analysed from the point of view of coordination between stem and nectophores, and an electron microscope study of the effectors and conducting elements has been carried out. Coordination between the stem and anterior nectophore involves two pathways, one epithelial and the other nervous. The nervous link consists of a bundle of small neurites and a single giant axon. There is some evidence that this mediates rapid escape behaviour. After the nerves have been cut, coordination is maintained via the epithelial route. Impulses can jump from epithelial cells into nerves but the transmission process is unclear. Neuro‐epithelial transmission involves conventional synapses. As in physonectid siphonophores, the stem has two nervous systems each with its own giant fibre, and a slow system, the endodermal epithelium. In the nectophore, marginal nerve centres generate a swimming rhythm. Conduction in the subumbrellar muscle is myoid. The exumbrellar epithelium and the subumbrellar endoderm are conducting tissues. Histological study reveals synapses in the predicted locations and gives details of myo‐epithelial organization and nervous layout. Novel histological features include elements resembling steroid‐secreting cells, which ensheath nerves and are innervated by them, and innervated giant non‐nervous cells lying between the nerve ring and the hydroecium. The subumbrellar muscle cells are shown to have sarcolemmal invaginations reminiscent of the f‐tubule system of vertebrate muscle.

Description: The authors believe that Globorotalia mayeri Cushman and Ellisor and Globorotalia siakensis LeRoy cannot be maintained as separate taxa. This opinion comes after reexamination of the holotype of Globorotalia mayeri and of additional illustrations of the holotype of Globorotalia siakensis together with examination of large numbers of specimens of the plexus from Bodjonegoro-1 well in Java and from Trinidad in the Caribbean. Both taxa were described in 1939 but, due to the rules of priority, Globorotalia mayeri would now be the valid name. We consider that Globorotalia continuosa Blow is a four-chambered variant of Globorotalia mayeri that cannot usefully be separated from it.

Description: Pairs of individually recognizable male Octopus vulgaris were observed in a large seawater tank containing two suitable homes (brick pots or plastic buckets). None of the animals established exclusive occupancy of one home and for much of the time both animals were associated together at the same site. Usually one of the two homes was preferred and its occupant was most likely to be the larger animal, or the earlier resident if they were of equal size. Large animals were observed to take food forcefully from smaller octopus. An arm alignment interaction is described which, it is suggested, may be a means by which two octopuses establish their relative sizes.

Description: The major light and dark components of body displays are described and classified for the octopus Eledone cirrhosa (Lamarck) under aquarium conditions. Comparisons are made with Octopus vulgaris and Eledone moschata. Upon the basic similarity of white display components in the three species is superimposed a trend of modification. Dark components are less various in Eledone cirrhosa and although the chromatophores are organised with leucophores into chromatic units these are not clearly limited morphologically by “grooves”. The mottle patterns of Eledone seem to be arranged along the longitudinal and latitudinal (radial) axes of the animal, the grade of mottle does not respond to grade of background contrast.

Description: A program of geophysical research was carried out as a preliminary stage of study of the Santorini volcanic group. This area is of remarkable geothermal and volcanological interest, and the definition of a volcanological structural model is the starting point for an understanding of the local geodynamic processes. Gravity, magnetic and geoelectrical data proved that: (i) the core of the volcanic edifice consists of a sedimentary-metamorphic basement; (ii) the basement is tectonically disturbed and a linear tectonic system produces a graben-type structure in the middle part of the area.

Description: The spatial distribution of shortfin squids in the area between the Gulf Stream and Nova Scotian shelf is analysed based on the data collected during the joint Soviet-Canadian cruise aboard the RTM "Belogorsk" in 1979. A detailed analysis of the hydrological data is made indicating a close correlation between the squid distribution and the structure of water masses in the area. Relationships between the squid distribution and oxygen minimum and temperature profile, as well as between the squid abundance and proportion (per cent) of the North Atlantic Central Water in the slope water masses are established. A method of estimating the young shortfin squid abundance in the given area based on T-S analysis of water masses is proposed. The hypothesis is suggested that larval squids are transported from the continental slope to the northern boundary of the Gulf Stream.

Description: During a 10-year study more than 2,000 phytoplankton samples were collected from the entire coast of Peru and analyzed. In general, diatoms were the most abundant group of organisms in all seasons. Predominant species were Rhizosolenia delicatula, Skeletonema costatum Thalassiosira subtilis, Thalassionema nitzschioides and several species of the genus Chaetooeros. Dinoflagellates and flagellates were observed frequently during summer. The mean distribution of the phytoplankton concentration during the 10 years shows the existence of several centers with higher cell densities along the coast, coinciding with the areas of more intense and persistent upwelling. Four major centers have been identified: Pimentel (˜6°S), Chimbote (˜9°S), Callao (˜12°S), and Tambo de Mora-Pisco (˜15°S); and two minor centers, Talara (˜4°S) and Ilo (˜17°S). The relative importance of each center seems to change according to the season. The highest phytoplankton concentration tended to be in the northern part of the coast during fall and winter and in the south through spring and summer.

Description: Die Probleme, die bei Speciesuntersuchungen von Spurenelementen mit Hilfe der Differentialpuls Anodic Stripping Voltammetrie auftreten, werden zu-sammenfassend dargestellt. Neben den bei der eigentlichen Bestimmung auftretenden Problemen, werden auch solche erwähnt, die mit der Probennahme sowie der Lagerung und Vorbehandlung der Proben in Zusammenhang stehen.

Description: 1. PCBs were administered to juvenile soles (Solea solea) with food. Homogenates of gut, liver, brain, dark skin, muscle and gills were analysed for their contents of individual PCB components. The relative contributions of individual components to total PCB were virtually indentical in the various organs sampled at the same day in a 275-day period. 2. During the experiment concentrations on a (pentane-extractable) lipid basis of most PCB components declined in all organs regardless of lipid metabolism. The results suggest that PCB patterns in organs are determined by equilibrium partitioning. So components remained mobilizable from organs whose lipid contents increased. This is in contrast with the idea that PCBs are taken up and stored in lipids under circumstances of increasing lipid content in organs. 3. The plateau-values of the steady-states of lipid based concentrations of PCB components decreased in all organs. This might have been due to changes in lipid contents or lipid composition in some organs.

Description: Sponges are diploblastic acoelomate Metazoa. They are sedentary, filter-feeding animals which utilize a layer of flagellated cells to pump a unidirectional water current through themselves. They are found in freshwater, but more abundantly in marine habitats. Sponges have been persistent throughout geological time from the Precambrian to the Recent, with special success during the Paleozoic. They are apparently the most primitive multicellular animals on a phylogenetic scale ranked by morphological complexity, although the levels of physiological and biochemical complexity found in sponges easily measure up to the degree of sophistication found in so-called higher animals. The Porifera (sponges) and Coelenterata are related as two phyla representing distinct stocks, but stemming from a presumed common although presently unknown origin (Hyman, 1940).

Description: The type species of Dictyonema is D. retiforme Hall, 1851 from the Middle Silurian Rochester Shale of New York. Although incomplete, the type specimen probably belongs to the benthic group of dendroid graptolites which ranged from the Late Cambrian to early Late Carboniferous. It is proposed that the plank tie, near-cosmopolitan 'Dictyonema' flabelliforme is phylogenetically quite distinct and belongs to the unattached coni-siculate dendroid family Anisograptidae Bulman, with Radiograptus Bulman as probable ancestor. The Anisograptidae are not directly related to the benthic dendroid family Dendwgraptidae Roemer, of which Dictyonema is a member, although they may be indirectly descended from it. The planktic species 'Dictyonema' flabelliforme is revised and referred to the genus Rhabdinopora Eichwald, 1855. 'Dictyonema' norvegicum Kjerulf and 'D' graptolithinum Kjerulf are regarded as junior synonyms of Rhabdinopora flabelliformis (Eichwald). The coni-siculate planktic family Anisograptidae is reorganized into three subfamilies. The Anisograptinae n. subfam. includes essentially horizontal pauci- or non-dissepimentous genera (Radiograptus, Staurograptus, Anisograptus, Adelograptus, Aletograptus, Triograptus and Kiaerograptus); the Rhabdinoporinae n. subfam. includes pendent conical genera (Rhabdinopora, Bryograptus and doubtfully Sagenograptus); and the (possibly polyphyletic) Clonograptinae n. subfam. includes horizontal forms principally developing from a single dicalycal bud of th11 (Cionograptus, Temnograptus, ?Stellatograptus).

Description: We studied the alteration of silicic volcanic glass of recent Towada ash in the different soil environments by means of electron-microprobe analysis. Two types of glass alteration (tentatively named [alpha] and [beta] types) were established and were distinguished on the basis of potassium and calcium contents of the glass samples. The [alpha] type glass alteration was characterized by a very large gain of potassium and a large loss of sodium. This alteration was explained by the ion exchange reaction between Na+ and H+ plus K+ without significant change in the glass structure. The [beta] type alteration characteristically showed a significant loss of potassium and a large gain of calcium and some other elements. The behaviors of alkalies and alkaline earths in the [beta] type glass could not be interpreted by the stoichiometry of exchange processes of these elements. Changes of glass structure during weathering were suggested for the [beta] type glass. There were close relationships between the mode of glass alteration, clay mineralogy of ash-derived soils, and soil environments. Only [alpha] type glass alteration was observed in the 2:1 mineral soils that showed the very low pH, very low contents of exchangeable bases, but relatively high content of exchangeable potassium. In contrast the [beta] type glass alteration was the most intense in the allophanic Ando soil, which showed a relatively high content of exchangeable bases and a high pH.