ALBERT

Description: Iron-manganese nodules from the ocean floor have been extensively studied. But, because of the fine grain size of the particles of the nodules, structural identification by X-ray and electron diffraction techniques is difficult and the mineralogy of the iron oxide phase has not been well characterized. The observation of the Mössbauer spectrum-in which each nucleus absorbs gamma-rays independently-is not limited by particle size in the same way as is the observation of Bragg peaks in diffraction measurements, in which radiation must be scattered coherently from a large number of atoms. The magnetic hyperfine splitting in the Mössbauer spectrum of magnetic materials is affected, however, when the particles are so small that they become superparamagnetic. We describe here an investigation using the 57Fe Mössbauer effect of two iron-manganese nodules in which the iron oxide phase could not be detected by X-ray or electron diffraction.

Description: The area of distribution of most Myriophyllum species is insufficiently known. In this paper, many new localities are recorded for 16 species from SE. Asia, Malesia, Madagascar, and Africa, and a key is added. One species from New Guinea, M. coronatum, is described as new (fig. I). Of the other species the synonymy is complete, but no descriptions are given; of each the distribution and ecology is cited, and if necessary critical remarks are added.\nUnder the new species the second remark deals with the possible desirability of distinguishing subgenera or sections within the genus. It is concluded that, as the species show a reticulate affinity by parallelism, especially as regards reductions in both vegetative and sexual organs, the usefulness of distinguishing infrageneric taxa is debatable and not advisable.

Description: The type-material of Tachinidae described from Indonesia and housed in the Zoological Museum in Amsterdam is listed, its status determined and its data cited. Twentyfour lectotypes are newly designated for nominal species based on syntypes. Paralectotypes located in other museum collections are recorded for all those nominal species of which the lectotype is in Amsterdam, so as to provide complete information on the original type-material.

Description: 1. A detailed study was made of the subsequent stages in the colour change of the Stoat, Mustela erminea Linnaeus, 1758. 2. Starting and finishing date of both Autumn and Spring moult were determined, based on the examination of 300 pelts from the Netherlands. 3. An indication was found for the existence of a difference in finishing date of the Spring moult in male and female Stoats. The examinations showed that female Stoats complete their summercoat a good month earlier than males. 4. It appeared that there is a remarkable difference in number of completely white animals between warmer and colder parts in the Netherlands. The colder regions hold much more completely white animals. This indicates that temperature has an influence on whether Stoats turn completely white or have a variegated wintercoat.

Description: 1. The real identity has been studied of juvenile gammarids, that were found in the fresh-water tidal region of the River Slack (France), 3 to 4 km inland of the mouth of its estuary. At the outset, these juveniles were (on basis of their morphology) considered to belong to Gammarus salinus. 2. Rearing demonstrated that the juveniles in question developed into adult Gammarus zaddachi. This indicates that the morphological criteria used in discriminating between G. salinus and G. zaddachi fail in juvenile material. Several morphological criteria are discussed and tested. It appears that a 100% certain key character does not exist, meaning that it is not possible to identify with absolute certainty all individuals in mixed populations of the two species. 3. At the same time, the resemblance of juvenile G. zaddachi to adult G. salinus provides us with a morphological feature allowing rapid distinction between adult and juvenile G. zaddachi in studies with large numbers of individuals. 4. In studies of the reproduction and migration of G. zaddachi, several types of nets were developed, both for anadromous and catadromous migrants. These nets agreed with one another in having the same catch capacity. 5. The activity of G. zaddachi shows a diurnal periodicity, the activity peak falling at night.\nThis behavior results in a down-river migration (\xe2\x80\x9cdrift\xe2\x80\x9d), which reaches its maximum 2 to 3 hours after sunset, slowing down later in the night, until the drift virtually stops at sunrise. No influence of the light intensity during the night (moon phase, clouds) was found. 6. During the periods with H.W.S., the direction of the stream reverses in the entire study area. In the parts of the river adjacent to the estuary, this stream reversal is accompanied by a rapid increase in salinity. In the more up-river reaches, no salinity changes occur, so that we find there a fresh-water tidal region. 7. All year round a certain part of the population of G. zaddachi living at a given place (the so-called standing crop) migrates down-river. During the autumn equinoxal spring-tides (and \xe2\x80\x94 though much less \xe2\x80\x94 during the spring equinox) mass migration takes place in up-river direction. This up-river migration takes place only at nights in which the stream reverses under the influence of the H.W.S. Practically exclusively juvenile animals participate in the up-river migration. 8. Per night, the maximum number of animals caught per net (= 30 X 50 cm) was 1,500 downstreamers and 6,000 upstreamers of G. zaddachi, which may roughly correspond with 30,000 downstreamers and 120,000 upstreamers per given section of the river. No other gammarid species in the river Slack shows migratory behavior. 9. Tagging experiments showed, that animals migrating up-river cover distances of 40 to 60 m per night. Downriver migrants cover at least 50 m and at most 80 m per night. 10. Several indications make it plausible that, though G. zaddachi uses the water currents for its migration, the up-river and down-river movements are not merely accidental transportation. Animals in the (physiological) phase of moving down-river continue to do so, irrespective of the direction of the stream. The same holds true for animals in the phase of moving in up-river direction. 11. The reproductive cycle of G. zaddachi is completed in one year. The young appear in spring, in autumn these juveniles grow adult, the first ovigerous females appear in December, the maximum production of eggs falls in the early spring. All adults die after the reproduction period. 12. The reproductive cycle is coupled with the migration cycle. The females participating in down-river migration can, dependent on temperature and salinity, successfully produce an offspring. At temperatures above 7\xc2\xb05C this happens only in the mixohaline parts of the river Slack. When the temperature drops below 7\xc2\xb05 C, egg production is also possible in the limnic reaches of the river. The juveniles pass the summer in the estuarine region. In this season an important portion of the up-river distribution area of G. zaddachi is depopulated. Repopulation of the limnic region by juveniles takes place in the fall, aided by the reversed water currents at H.W.S., thus completing the cycle.

Description: 1. From 54 female fin whales chosen at random from a greater number of animals from which data and material were collected during the Antarctic whaling season 1962/1963, records have been made of the baleen plates and the ear plugs.\nFor the records the complete baleen plates including the part of the plates embedded in the gum are used. All ear plugs used for this study were complete and undamaged. 2. According to their ovaries and baleen records 50 animals were sexually mature, 4 animals were sexually immature. 3. In each individual the record of the complete baleen plate is entirely comparable to the record of the ear plug, in its general trend and in the sequence of peaks and hollows. Also the regular cyclic repetition found in the records of the baleen plates is present in the records of the ear plugs. The comparison of the records of baleen plates with those of ear plugs is only possible when it starts with the last formed part, forming the basis of the core of the plug and the first part of the cortex of the baleen plate deep in the gum, because these represent both the same moment in the life of the animal which is exactly known, viz. the moment in which the growth stopped due to the death of the animal.\nTable III \xe2\x80\x9cGrowth periods\xe2\x80\x9d in the ear plug, per period the mean length number of animals i ii m rv V VI vn VIII IX 4 69 2 53 56 8 62 68 72 8 70 67 73 71 10 63 64 63 61 59 5 59 57 60 63 58 57 6 54 57 61 56 58 58 59 5 69 72 68 67 67 65 65 62 1 66 58 51 62 59 54 49 64 48 total mean 63 64 66 64 60 60 61 63 48 4. In the records of baleen plates and ear plugs of a number of immature animals the \xe2\x80\x9cdouble hump\xe2\x80\x9d or a part of it was found at the right hand side of both. In some of the animals an \xe2\x80\x9covulation peak\xe2\x80\x9d was present at the same time at the beginning (left hand end) in the record of the baleen plate and ear plug; in both in the same position with respect to the surrounding peaks and hollows. This is also true for the records of ear plugs and baleen plates of older females. 5. The records of the ear plugs can be divided into \xe2\x80\x9cgrowth periods\xe2\x80\x9d according to what is done in the records of the baleen plates. In each individual the division between the \xe2\x80\x9cgrowth periods\xe2\x80\x9d in the record of the ear plug are in the same position with respect to the sequence of the surrounding peaks and hollows as is found in the record of the complete baleen plate. In both records the cyclic repetition of peaks and hollows in the successive \xe2\x80\x9cgrowth periods\xe2\x80\x9d is clear. 6. In 21% of the animals examined the number of \xe2\x80\x9cgrowth periods\xe2\x80\x9d in the record of the ear plug is equal to the number present in the record of the baleen plate. In 17% of the animals examined the number of \xe2\x80\x9cgrowth periods\xe2\x80\x9d in the record of the baleen plate was lower (1 to 3 \xe2\x80\x9cgrowth periods\xe2\x80\x9d) than was found in the record of the ear plug. In 62% of the animals examined the number of \xe2\x80\x9cgrowth periods\xe2\x80\x9d in the baleen plate was greater (1 to 6 periods) than was found in the ear plug. 7. Evidence was put foreward that the increase in length of the ear plug is obstructed after the animal has reached a certain age. This moment is not the same for all animals but is probably related to the various \xe2\x80\x9cconstitution types\xe2\x80\x9d present in the catch. It is shown that in the distal end of the ear plug the length of the \xe2\x80\x9cgrowth periods\xe2\x80\x9d suddenly decreases, so only a certain maximum number of \xe2\x80\x9cgrowth periods\xe2\x80\x9d can be found. In the baleen plate the same situation exists due to wear at the tip of the plate. For these reasons the exact age of a fin whale can only be determined as long as wear at the tip of the baleen plate and compression of the distal layers of the ear plug does not occur. 8. From the evidence put foreward it is clear that age determination in fin whales by simply counting the layers present in the core of the ear plug is far too subjective and does not give reliable results. In our opinion best results for age determination in fin whales are obtained by counting the corpora present in the ovaries of females. When this number is divided by the mean ovulation rate (1.25, see Van Utrecht-Cock, 1966) and by adding 6 years (mean number of years before attainment of sexual maturity) the age of the animals calculated in this way is reasonably accurate.

Description: 1. Eight species of Cuban bat trematodes have been examined, and their excretory system established. 2. In Urotrema scabridum Braun a small V-shaped excretory bladder and the flame cell formula 2[(2+ 2+2) + (2+2+2)] were ascertained. This enabled us to affiliate the family Urotrematidae to the Microphalloidea sensu Odening (1964) within the suborder Plagiorchiata. A new key to the families of the Microphalloidea is given. 3. The genus Ochoterenatrema characterized by a pseudogonotyl is divided into the two subgenera Ochoterenatrema (with pretesticular vitellaria) and Morenodendrium n.subgen. (with posttesticular vitellaria). Both subgenera have a V-shaped excretory bladder and the flame cell formula is 2[(2+2+2) + (2+2+2)], as stated for the species O. (O.) diminutum (Chandler) and O. (M.) pricei (P\xc3\xa9rez Vigueras) n.comb. 4. Keys for determinating all known species are given together with the description of a Parabascus and two Postorchigenes species. The flame cell formulas tally with all the hitherto known formulas of both genera: 2[(2+2+2) + (2+2+2)]. 5. The species Limatulum solitarium P\xc3\xa9rez Vigueras is regarded preliminarily as valid, all Cuban findings of Limatulum are attributed to it. The flame cell formula is 2[(2+2+2)+(2+2+2)]. 6. In the fish-eating bat Noctilio leporinus mastivus a Pygidiopsis species (Heterophyidae) occurs, the flame cell formula of which is 2[(2+2+2) + (2+ 2+2)].

Description: A second supplementary list is given of endo- and ectoparasites collected from wild mammals in the Netherlands.

Description: CONTENTS\nIntroduction .................. 4\nAcknowledgements................. 5\nSystematic part.................. 7\nZosterops (concluded)................ 7\nTephrozosterops................. 167\nMadanga................... 169\nLophozosterops................. 171\nOculocincta.................. 204\nHeleia.................... 207\nChlorocharis.................. 212\nWoodfordia.................. 220\nRukia.................... 225\nMegazosterops.................. 232\nGenus incertae sedis (Hypocryptadius)........... 235\nAdditions and corrections to part I............ 240\nAdditions and corrections to part II............ 276\nSummary and conclusions............... 295\nIntroduction.................. 295\nTheoretical and practical classification........... 296\nA revised list of the Indo-Australian Zosteropidae....... 303\nEcology as an aid in classification........... 311\nCompetition and evolution.............. 313\nHistorical and zoogeographical considerations on some species and subspecies 319 Plumage characters................ 326

Description: In de laatste jaren heeft het Rijksmuseum van Natuurlijke Historie enkele vermeldenswaardige Crustacea ontvangen, die uit de Nederlandse wateren en uit de zuidelijke Noordzee afkomstig zijn. Twee van deze bleken tot soorten te behoren die nog niet eerder uit ons land vermeld waren, te weten de garnaal Eualus occultus en de zeepok Stomatolepas elegans. De garnaal Palaemon adspersus is vroeger wel genoemd als deel uitmakend van onze fauna, doch deze opgaven berusten op foutief gedetermineerde exemplaren; recente vondsten echter tonen aan dat de soort toch tot onze fauna behoort.\nVan Callinectes sapidus, een uit Amerika afkomstige krabbensoort die vroeger reeds uit Nederland vermeld werd, is hier onlangs een levend wijfje uit de zuidelijke Noordzee aangevoerd, terwijl ook enkele dode exemplaren aan onze kust aanspoelden.\nGaarne spreek ik hier mijn dank uit aan de heren G. R. Heerebout en W. J. Wolff, beiden van het Delta Instituut voor Hydrobiologisch Onderzoek te Ierseke, voor het verschaffen van materiaal en belangrijke inlichtingen.\n\nDECAPODA BRACHYURA\nCallinectes sapidus Rathbun, 1896 (tekstfig. 1, pl. 1) Callinectes sapidus is een grote zwemkrab, waarvan het rugschild een breedte van meer dan 20 cm kan bereiken. Deze maat is enigszins geflatteerd door het feit dat het rugschild aan beide zijden eindigt in een forse zijwaarts gerichte stekel, die bij het meten meegerekend wordt. De voorrand van het schild draagt tussen de ogen en de zij stekels acht scherpe tanden, die minder dan half zo lang zijn als de zijstekels. Tussen de ogen staan aan de voorrand van het rugschild twee brede driehoekige stompe tanden. De kleur van de