Valentia Observatory Research Articles

Extreme Value Analysis of Ground Magnetometer Observations at Valentia Observatory, Ireland

AbstractUnderstanding global space weather effects is of great importance to the international scientific community, but more localized space weather predictions are important on a national level. In this study, data from a ground magnetometer at Valentia Observatory is used to characterize space weather effects on the island of Ireland. The horizontal component of magnetometer observations and its time derivative are considered, and extreme values of these are identified. These extremes are fit to a generalized extreme value distribution, and from this model return values (the expected magnitude of an observation within a given time window) are predicted. The causes of extreme values are investigated both in a case study, and also statistically by looking at contributions from geomagnetic storms, substorms, and sudden commencements. This work characterizes the extreme part of the distribution of space weather effects on Ireland (and at similar latitudes), and hence examines those space weather observations which are likely to have the greatest impact on susceptible technologies.

Ichnology and depositional environment of the Middle Devonian Valentia Island tetrapod trackways, south-west Ireland

Nine tetrapod trackways are described from the Middle Devonian continental Valentia Slate Formation on the north-eastern coast of Valentia Island in County Kerry, Ireland. The trackways occur at three sites – Dohilla, Coosadillisk and Culoo Head – the latter two being recorded for the first time. Morphological and taphonomic analyses of the trackways suggest they were made by populations of similar tetrapods, but of varying size (body length=0.5 to 1m; width=0.15 to 0.30m), that moved in some cases by terrestrial locomotion and in others possibly by a slow “paddling gait” while the substrate was submerged by very shallow floodwater. Sedimentological facies analysis of the trackway-bearing sequences has been carried out for the first time and shows that the preserved trackways are associated with the late stages of (1) a principal river channel margin (Coosadillisk), (2) a minor floodplain drainage channel (Culoo Head) and (3) a sand-rich crevasse splay/medial alluvial-ridge environment (Dohilla). The Valentia Island tetrapods inhabited marginal environments of proximal river channels <20km from the northern margin of the Munster Basin, where hinterland drainage basins probably provided reliable sources of water in an overall semi-arid climate. It is proposed that the more perennial river channel belts crossing the basin would have provided conducive route ways that allowed ancestral tetrapods to migrate (>170km) northwards into the continent from postulated shallow marine habitats as they evolved this capability over a potential 4–5 million year period during the Middle Devonian.

Thinopus and a Critical Review of Devonian Tetrapod Footprints

Devonian tetrapod tracks and trackways can be recognized by three criteria: morphology of the manus and pes impressions that matches known Devonian tetrapod skeletal morphology, manus smaller than pes, and the alternating trackway pattern that results from lateral sequence walking in quadrupedal tetrapod locomotion. The first reported Devonian tetrapod track, named Thinopus antiquus, from Pennsylvania, is not a tetrapod track and is likely an impression of a fish coprolite(s). A critical review of the published Devonian track record indicates only three can be verified as produced by a tetrapod trackmaker—Genoa River, Australia; Easter Ross, Scotland; and Valentia Island, Ireland. The supposed tetrapod tracks from the Middle Devonian of the Zachełmie quarry, Poland, fail the criteria for identification as Devonian tetrapod tracks. Indeed, no convincing case has been made that the Zachełmie structures are tetrapod tracks. Instead, they are reinterpreted as fish nests/feeding traces (ichnogenus Piscichnus). The oldest Devonian tetrapod trackway is Givetian and this is the oldest record of a tetrapod, but the sparse record of Devonian tetrapod tracks is of no other biostratigraphic and little paleobiogeographic significance. Bona fide Devonian tetrapod tracks are from nonmarine facies, so they do not support a marginal marine origin of tetrapods. They indicate lateral sequence walking and pelvic-limb-propelled, fully terrestrial (subaerial) locomotion in freshwater environments by at least some Devonian tetrapods.

Evaluating the dendroclimatological potential of Taxus baccata (yew) in southwest Ireland

Tree-ring research in Ireland has typically been dominated by Quercus species, particularly Quercus petraea and Quercus robur. Recent years have seen a greater focus on multi-species reconstructions in Ireland but, due to difficulties with the hardness of the wood, missing/pinched rings and fused stems, Taxus baccata has not been included in these investigations. Despite these difficulties, a 31-tree, 204-year T. baccata chronology was successfully constructed from Killarney National Park, southwest Ireland. The chronology exhibits promising dendroclimatological potential, with climatic responsiveness equivalent to that of the other major Irish tree taxa, including Quercus. The chronology shows the strongest relationship with May–June precipitation from Muckross House synoptic station (1970–2007; r=0.521, p<0.01) and Valentia Observatory (1941–2007; r=0.545, p<0.01). November–April temperatures also exhibited a strong relationship with the chronology post-1970 (r=0.605, p<0.01 for Muckross House, r=0.567, p<0.01 for Valentia Observatory), but this relationship is not time stable and breaks down for the pre-1970 Valentia Observatory record. The long-lived nature of T. baccata, the exceptional preservation of wood and rings in this hard softwood species, as well as its prominence in Irish archaeology, all point to the potential to expand this chronology both spatially and temporally, and demonstrate T. baccata's potential in multi-site and multi-species tree-ring studies in the region.

Assessing the Influence of a Range of Spring Meteorological Parameters on Tree Phenology

The timing of phenological phases, such as leaf unfolding of trees, is partly driven by the weather. The impact of weather on the spring phenology of a selection of tree species in the phenological garden at Valentia Observatory, Caherciveen, County Kerry, Ireland, for the period 1967-2004 was assessed. In particular, the beginning of the growing season (BGS), as determined by the date of leaf unfolding, was considered. The impact on BGS of a range of meteorological parameters and derived parameters, including minimum, maximum and mean air temperature (°C), soil temperature (°C), rainfall (mm), sunshine (hours), number of air frost days and number of rain days was investigated. These parameters were averaged or summed over the months of February, March and April and linear regression analysis with BGS was carried out for several tree species. The results showed that the regression coefficients of BGS on minimum air and soil temperature were highest, with Populus canescens and Populus tremula showing the strongest relationships. Temperature parameters were found to be more important in driving advancing phenology than any other meteorological parameter tested.

The hourly gale record from Valentia Observatory, SW Ireland 1874–2008 and some observations on extreme wave heights in the NE Atlantic

The sustained hourly gale record from Valentia Observatory, SW Ireland over the time period from 1874–2006 shows very significant variations including high values in the 1920s, 1940s, 1960s and 1980s but a decline since then down to the lowest recorded levels at present. Most gales occur in winter and in particular in December and January. An analysis of the wind duration and speed data shows that there has been increased variability in the duration of gales over the last 20 years and despite an overall decline in mean wind speed there is no indication that gale strengths have changed in any systematic way. This gale data is strongly in contrast to the outputs and predictions from the various scenarios in the ECHAM4 models which predict at worst no changes in cyclonicity of depressions below 1,000 hPa but significant increases in cyclonicity of severe depressions below 940 hPa. At present the actual data is running contrary to the model outcomes at Valentia and elsewhere in Ireland. The sustained gales have given rise to wave heights in excess of 30 m and this documentary evidence is verified by more recent satellite and marine buoy data.

Chemical trends in background air quality and the ionic composition of precipitation for the period 1980–2004 from samples collected at Valentia Observatory, Co. Kerry, Ireland

A major Irish study, based upon more than 8000 samples collected over the measurement period of 22 years, for sulfur dioxide (SO2-S), sulfate (SO4-S) and nitrogen dioxide (NO2-N) concentrations (microg m(-3)) within air, and the ionic composition of precipitation samples based on sodium (Na+), potassium (K+), magnesium (Mg2+), calcium (Ca2+), chloride (Cl-), sulfate (SO4-S), non-sea salt sulfate (nssSO4-S), ammonium (NH4-N), and nitrate (NO3-N) weighted mean concentrations (mg l(-1)), has been completed. For the air samples, the sulfur dioxide and sulfate concentrations decreased over the sampling period (1980-2004) by 75% and 45%, respectively, whereas no significant trend was observed for nitrogen dioxide. The highest concentrations for sulfur dioxide, sulfate and nitrogen dioxide were associated with wind originating from the easterly and northeasterly directions i.e. those influenced by Irish and European sources. The lowest concentrations were associated with the westerly directions i.e. for air masses originating in the North Atlantic region. This was further verified with the use of backward (back) trajectory analysis, which allowed tracing the movement of air parcels using the European Centre for Medium range Weather Forecasting (ECMWF) ERA-40 re-analysis data. High non-sea salt sulfate levels were being associated with air masses originating from Europe (easterlies) with lower levels from the Atlantic (westerlies). With the precipitation data, analysis of the non-sea salt sulfate concentrations showed a decrease by 47% since the measurements commenced.

An analysis of the ionic composition of Irish precipitation and background air quality since 1980 based on samples collected at Valentia Observatory, Co. Kerry, Ireland

This work has investigated the ionic composition of precipitation samples based on measuring Na, K, Mg, Ca, Cl, SO4-S, NH4-N, NO3-N (mg/L) and the trends of SO2-S, SO4-S, and NO2-N (μg/m) concentrations in air samples collected on a daily basis at Valentia Observatory, Cahirciveen, Co. Kerry, Ireland and analysed in the Met Eireann laboratory over the period 1980 2004. The time series of annual average SO2-S and SO4-S concentrations (μg/m) for the air data shows a distinct downward trend. The NO2-N concentration (μg/m) levels have remained relatively stable since measurements commenced in 1989. No such obvious trends are visible from the original precipitation data; however, by investigating the contribution of sea-salt sulphate to the total sulphate levels it is possible to conclude that the non-sea salt sulphate levels (i.e. anthropogenic contribution) have decreased since the measurements have commenced. The location of the site on the south west coast results in exposure to the Atlantic Ocean and this results in considerable contribution of ions from the sea that is clearly shown from the wind sector analysis of the precipitation samples for Na, K, Mg, Ca and Cl. The air data shows that the highest concentrations for the SO2-S and SO4-S and NO2-N are correlated with winds coming from an easterly and northeasterly direction (which is also confirmed from the non-sea salt sulphate levels for the precipitation results). The lowest concentrations were found for westerly directions. This has also been proven correct with the use of back trajectory analysis, which has allowed tracing the movement of air parcels using ECMWF analysis fields.

Haplostomides Hibernicus (Copepoda: Cyclopoida) Living in the Compound Ascidian Polyclinum Aurantium

Abstract The female of Haplostomides hibernicus (Scott and Scott, 1895) is fully redescribed on the basis of a single specimen living in the compound ascidian Polyclinum aurantium Milne Edwards, which was obtained at Strangford Lough in the Irish Sea in 1995. This copepod was collected by the author, together with specimens of H. scotti Chatton and Harant, 1924, from the same ascidian. The redescription confirms that the specimen of H. hibernicus is comparable in morphology to the copepods that Scott and Scott (1895) described as (?)Enterocola hibernica from Valentia Island and that Chatton and Brement (1910) redescribed as Aplostoma hibernica from Roscoff. The result of this study indicates that H. scotti is synonymous with (?)E. beaumonti Scott and Scott, 1895, which was found together with (?)E. hibernica in an unidentified ascidian at Valentia Island.

U-Pb zircon geochronology of silicic tuffs and chronostratigraphy of the earliest Old Red Sandstone in the Munster Basin, SW Ireland

Abstract Newly acquired U-Pb magmatic zircon dates from silicic tuffs within the Old Red Sandstone (ORS) magnafacies of the Munster Basin (SW Ireland) are intercalibrated with newly discovered (late Givetian) and reappraised (mid-Frasnian) miospore assemblages to provide the first biostratigraphically constrained numerical ages in the Irish Devonian succession. The weighted mean 207 Pb/ 206 Pb isotopic age determined for the Keel Tuff Bed (385.0±2.9 Ma) is indistinguishable from that of the previously investigated Enagh Tuff Bed (384.9±0.7 Ma). In conjunction with very similar rare earth element (REE) signatures, this confirms their correlation, placing a minimum age of 384.9±0.4 Ma on the newly discovered Reenagaveen microflora, which is assigned to the late Givetian TCo Oppel zone. The equivalence of the Keel and Enagh Tuffs constrains a vertebrate fauna containing Bothriolepis and the Valentia Island tetrapod ichnofauna to pre-date this event. Isotopic dating of thickly bedded subaerial tuffs from the Lough Guitane Volcanic Complex, a major accumulation of rhyolites and silicic volcaniclastic rocks, reveals ages of 384.5 ± 1.0 Ma (Killeen Volcanic Centre), indistinguishable from the Keel-Enagh Tuff Bed, and 378.5±0.2 Ma from the Horses Glen Volcanic Centre, previously considered to be the oldest of the complex. The Horses Glen Centre post-dates the Moll’s Gap Quarry microflora, the only current biostratigraphical control on the age of the early ORS in the east of the basin depocentre, thus indicating a minimum age for the (mid-Frasnian) IV Oppel zone, the revised biostratigraphic age of this assemblage. These controls on the early ORS (1) suggest that Munster Basin initiation occurred before late Givetian time and (2) give time-averaged (compacted) accumulation rates of c. 0.17–0.25 and 0.18 mm a −1 for eastern and western Iveragh, respectively. The minimum basin duration time was c. 23 Ma to the end of the Devonian period. The implications of these data for the depocentre stratigraphy, volcanic events, proposed ORS cyclicities and the geohistory of the Munster Basin are examined.

Long-term trends in, and spatial variation of, solar irradiances in Ireland

Analysis of the pooled data of global K↓, and diffuse D, irradiances measured at eight sites in Ireland, with time series varying from 14 to 42 years showed significant decreases averaging 16.39 MJ m−2 (0.62%) year−1 in K↓ and 3.10 MJ m−2 (−0.77%) year−1 in D. The long-term trends differed markedly between the eight pyranometer stations. No significant changes were found at the four northern stations. Significant increases were found at Dublin airport near the east coast, highly significant decreases were found at the three stations in the south of the country, including Valentia Observatory in the extreme south-west, whose measurements extended over 40 years. At Valentia, the decreases in K↓ and D, equivalent to −0.43% and −0.42% per year, respectively, were accompanied by significant decreases in radiation balance and hours of bright sunshine, −0.86% and −0.32% per year, respectively. Although no large or significant trends in daytime cloud cover were observed at Valentia there was a significant, negative interaction between K↓and the small, random interannual variations in cloud cover; the rate of decline in K↓ was three times larger in years of below-average cloudiness than in years of above average cloud cover. North–south gradients in K↓ and D were significant for both mean annual and mid-winter irradiances; the values measured at Dublin airport were anomalously high but appeared to be site-specific. Possible causes of the changes in irradiances found, and their agricultural, hydrological and climatological consequences are briefly discussed. © 1998 Royal Meteorological Society

A chronology of Irish history since 1500

A Chronology of Irish History since 1500 is a valuable addition to reference publishing in Irish Studies. It offers both the scholar and the general reader a chronology of Irish history, social and economic life, and literary and artistic achievement from the beginning of the sixteenth century to the present day. The book is arranged on a year by year basis. Within each year, the significant events of Irish life are listed by date in chronological order. Thus the reader or researcher can learn at a glance that in 1866, the Habeas Corpus Act was suspended in Ireland on 17 February; that Archbishop Paul Cullen of Dublin was created the first Irish cardinal on 22 June; that on 27 July the first submarine cable link between Valentia Island, Co. Kerry and Trinity Bay, Newfoundland was completed; and that on 17 December James Stephens was deposed as head of the Fenian Brotherhood in the United States, to be succeeded by Colonel Thomas J. Kelly. All this information is, in turn, collated in the extensive index which enables the reader quickly to discover the correct reference point for a person or event even in circumstances where he or she is uncertain of the exact year in question. In the case of particularly dramatic years in Irish history, such as 1798 or 1916, the authors give an extended date-by-date account of the unfolding events. A Chronology of Irish History since 1500 will become an essential reference tool for all who are concerned with Irish history, literature and culture.

The tides of the northeast Atlantic Ocean

The results of a ten-year programme of measurement and analysis of the tides in the open sea west of Europe are described. Instrumental techniques were developed during the period from capacitance-plane sensors used in shelf seas to strain-gauges and quartz crystal sensors used in oceanic depths up to about 4 km. The measuring stations form two chains, one on the edge of the shelf surrounding the British Isles, and the other surrounding an oceanic area bounded by Scotland, Iceland, the Azores and South Portugal, which is subdivided by a line of stations along the 53 1/2 ° parallel from Inishbofin to the mid-Atlantic Ridge. Records from tide gauges at strategic oceanic sites were collected and analysed over long periods to provide a basis for accurate analysis of the relatively short-term pelagic pressure records. Tidal admittances to the generating potential vary smoothly over the region except for a change in the age (phase slope) of the diurnal tides towards Reykjavik. The shelf-edge chain included current meters, enabling a direct estimation of the M 2 power transmission on to the shelf, namely 60 GW between Malin Head (Eire) and Floro (Norway) and 190 GW between Valentia (Eire) and the Brittany coast near Ouessant. When combined with known power fluxes into the Irish Sea and through the Dover Strait, these give figures for tidal dissipation in the North and Scottish seas that considerably exceed direct estimates based on bottom friction, confirming similar results by Robinson (1979) for the Irish Sea. Dissipation in the English Channel and western Celtic Sea is also much greater than was assumed by Miller (1966). Further, when the eastward flux of energy out of the ocean is computed solely on the basis of the cotidal map drawn for M 2 it is found that about 360 GW is fed into the shelf region between Lisbon and Valentia Island, indicating a substantial loss along the Biscay shelf south of Ouessant. Thus, all estimates of energy loss in the region studied greatly exceed previously assumed values. Dissipation within the main oceanic area itself is, however, about as small as expected. The diurnal tides in the shelf zones are considerably unlike Kelvin-waves, having short wavelength variations and a tendency for larger amplitudes on the open shelf than at the coast. This probably results from the presence of shelf-wave modes previously identified only in the region of St Kilda. The semi-diurnal tides however have much more regular behaviour along the shelf, with a Kelvin-wave profile west of Inishbofin. The tidal constants at two representative oceanic sites are compared with estimates from recent computational models, with wide ranges from fair agreement to disagreement, showing that tidal computations for the North Atlantic are not so uncontroversial as is often supposed. Avoiding reliance on computational modelling, the authors present cotidal maps of plausible accuracy for the constituents O 1 , K 1 , M 2 , S 2 and M 3 . Currents and power fluxes calculated from the M 2 map are presented and discussed. The principal oceanic amphidromes for the diurnal and semi-diurnal tides are west of the area studied, but their positions are estimated reliably. A major semi-diurnal amphidrome east of Iceland is confirmed, but there is no evidence for a supposed amphidrome centred on the Faeroe Islands. The cotidal map for M 3 is the first ever produced for an oceanic area. It contains two amphidromes near the mid-Atlantic Ridge.

DIURNAL CORRECTIONS TO MAGNETIC SURVEYS—AN ASSESSMENT OF ERRORS*

AbstractThe comparison of a group of continuous total field stations in Ireland with the record of the total field from Valentia Observatory enables the errors which would be involved in using the Observatory as a diurnal correction base to be examined. For the most part, for a single correction, these errors lie between ± 2 and ± 6 gammas. However, they have three notable characteristics: (i) they are not closely dependent on the magnetic ‘noisiness’ of the day, (ii) they are only marginally reduced by the application of station‐base time differences and (iii), they are strongly related to differences between the amplitude of the daily magnetic variation at the station and at the base. A permanent geographical basis for the latter differences enables a system for the estimation of the errors to be proposed.

The relation between the concentration of atmospheric condensation nuclei and other meteorological elements at valentia observatory

Measurements of the concentration of condensation nuclei made twice daily (0h and 12h GMT) with aNolan-Pollak photo-electric counter at Valentia Observatory, in the extreme Southwest of Ireland, over the 4 years 1951–1954, are analysed to show relation with other meteorological elements. It is found that concentration at 12h is generally higher than at (h and that precipitation at the time of observation or in the preceding hour reduces concentration by between 40% and 50%. From measurements made when there was no precipitation at the time or in the previous hour it is found that concentration decreases with increasing wind speed but does not vary appreciably with wind direction apart from a sector from which pollution could be expected. High concentrations are found with visibility below 7 miles, with inversion of temperature, when free from the effects of pollution, follows fairly closely that of duration of bright sunshine.

The Cellular Solution of the Dynamical Equations and the Actual Perturbation of the Westerlies up to 16 km at Valentia

The cellular solution of the linearized hydrodynamical equations requires the existence of nodal surfaces for the perturbation of air density, pressure and velocity components. When a constant, which appears in the formulae giving the heights of the nodal surfaces, is determined from the observed value of one of them, namely, the first nodal surface of the vertical velocity, all the other heights of nodal surfaces agree within reasonable limits with the heights determined from actual observations by several investigators using very different methods. More than 400 upper wind ascents reaching at least 16 km made by radio wind or radar methods at Valentia Observatory, have been classified according to the sign of the change of pressure at 8 km during the 12 hours prior to the ascent, and average values of the meridional and zonal components of the wind have been computed. The difference at each level between the corresponding average components of the wind when the pressure has increased and when the pressure has decreased gives a good approximation to double the value of the horizontal perturbation of the Westerlies. Applied to this case, the cellular solution requires that the zonal component of the perturbation so determined should be zero at all levels while the meridional component should have nodal surfaces at 4 and 12 km. The observations show that the zonal component is the one having nodal surfaces at the required levels while the meridional component has a maximum value at about 9 km. Taking into account that the equations refer to a single-layer atmosphere and neglect the meridional gradient of temperature, the disagreement between observation and theory appears to be less significant than the confirmation of the existence of nodal surfaces which cannot be explained by the generally accepted exponential solution of the dynamical equations. DOI: 10.1111/j.2153-3490.1954.tb01089.x

The Cellular Solution of the Dynamical Equations and the Actual Perturbation of the Westerlies up to 16 km at Valentia

The cellular solution of the linearized hydrodynamical equations requires the existence of nodal surfaces for the perturbation of air density, pressure and velocity components. When a constant, which appears in the formulae giving the heights of the nodal surfaces, is determined from the observed value of one of them, namely, the first nodal surface of the vertical velocity, all the other heights of nodal surfaces agree within reasonable limits with the heights determined from actual observations by several investigators using very different methods. More than 400 upper wind ascents reaching at least 16 km made by radio wind or radar methods at Valentia Observatory, have been classified according to the sign of the change of pressure at 8 km during the 12 hours prior to the ascent, and average values of the meridional and zonal components of the wind have been computed. The difference at each level between the corresponding average components of the wind when the pressure has increased and when the pressure has decreased gives a good approximation to double the value of the horizontal perturbation of the Westerlies. Applied to this case, the cellular solution requires that the zonal component of the perturbation so determined should be zero at all levels while the meridional component should have nodal surfaces at 4 and 12 km. The observations show that the zonal component is the one having nodal surfaces at the required levels while the meridional component has a maximum value at about 9 km. Taking into account that the equations refer to a single-layer atmosphere and neglect the meridional gradient of temperature, the disagreement between observation and theory appears to be less significant than the confirmation of the existence of nodal surfaces which cannot be explained by the generally accepted exponential solution of the dynamical equations.

North Atlantic Gale

THE last day of the old year and the first few days of the new have proved remarkably tempestuous on the North Atlantic. During the near approach to Ireland on December 31 of an exceptionally intense cyclonic depression, a destructive gale occurred in Ireland. At Valentia Observatory the pressure tube anemograph registered a gust of 96 miles an hour, which is the highest gust recorded there for at least sixteen years. Barometric readings in Iceland were unusually low during the three first days of 1933. On January 3, pressure at sea-level was less than 928 millibars (27.4 in.) near the centre of a depression lying off the south-west coast of Iceland, but it is not possible to say by how much it fell below that value. That depression was certainly among the deepest of which we have any record since daily synoptic weather charts of the North Atlantic were first begun. On those prepared and published by the Danish and German Admiralties, there is only one depression which looks to have had such a low reading, that of February 24, 1903, which had been preceded five days earlier by another only slightly less intense.

The factors affecting visibility at valentia observatory

The factors affecting visibility at valentia observatory

Contributions to the Comparative Anatomy of Some British Actiniæ

The main object of this paper is to give a comparative anatomical description of some British Anemones as well as to describe each individually; but the account is not so full as it was expected to be, as it was not possible to get all the species required.In most cases the specimens were examined externally before sections were cut. Each specimen was prepared according to the usual method used with paraffin wax, and I found during the progress of the work that borax carmine was the stain which gave the most satisfactory results.I should like to thank Miss E. de Fraine, D.Sc., Mr. F. W. Durlacher, and Mr. F. S. Wright for much assistance in the course of the work.For specimens collected and sent I am deeply indebted to Dr. E. J. Allen and his staff at Plymouth, Miss Delap, of Valentia Island, and Monsieur Louis Fage, of the Laboratoire Arago, Banyuls-sur-Mer, France.FAM. SAGARTIDÆ (Gosse, 1858).“Actiniinæ with a contractile pedal disk; body-wall smooth, or provided with verrucæ or tubercles, and usually perforated with cinclides, with or without a cuticle. Tentacles usually numerous and retractile, not very long, smooth, simple and generally entacmæous, sphincter muscle characteristically well developed and mesogloeal, occasionally diffuse endodermal, or even absent. At least six pairs of mesenteries, may be fertile or sterile. Acontia present.” The above is the definition used by Haddon in “The Actiniaria of the Torres Straits” in 1898. There has been a great deal of discussion concerning this family.