Search

DURING its reconnaissance of the asteroid 243 Ida, the Galileo spacecraft returned images of a second object, 1993(243)1 Dactyl1— the first confirmed satellite of an asteroid. Sufficient data were obtained on the motion of Dactyl to determine its orbit as a function of Ida's mass. Here we apply statistical and dynamical arguments to constrain the range of possible orbits, and hence the mass of Ida. Combined with the volume of Ida2, this yields a bulk density of 2.6 ± 0.5 g cm−3. Allowing for the uncertainty in the porosity of Ida, this density range is consistent with a bulk chon-dritic composition, and argues against some (but not all) classes of meteoritic igneous rock types that have been suggested as compositionally representative of S-type asteroids like Ida.

The utterances made by a moderately language-impaired adult with Down's syndrome, Ken, during 15 minutes of conversation were narrowly transcribed. It was found that pre-pausal rhythm groups containing the nuclear syllable had the best phonation and articulation; and the best rhythm in that a rhythm group whose plausible target was a dactyl (three syllables) or paeon (four) was much less likely to lose a syllable in such a position. Achieved dactyls and paeons were very rare in other prosodic positions, which led to some grammatical deficiencies, such as the inverted operator in a wh-question failing to be realized in any example. Ken often uses pre-pausal nuclear rhythm groups for a tag question which, though perhaps interactionally beneficial, relegates the main content of his utterance to the more distorted head rhythm groups and non-pre-pausal nuclear rhythm groups. These observations are discussed in terms of a speech planning model.

Two Platorchestia species arc recorded from Israel and the Sinai: P. platensis from near the sea shore at Naqaz Jirada (Sinai), and P. monodi from near springs and wells at En Hameara in the Negev Desert. Platorchestia monodi is distinguished from P. platensis in having a smooth palmar margin on the propod of male gnathopod 2, and the dactyl of male gnathopod 1 distinctly shorter than the propod palm. The occurrence of inland species of Platorchestia is discussed.

Nonnos was a Greek poet from Panopolis in Egypt (modern Akhmim), author of the Dionysiaca, an epic poem relating the life and triumph of Dionysos, and of a verse Paraphrase of the Gospel of John, both written in dactylic hexameters using epic dialect. Keywords: ancient Greece; Byzantine history; classical languages

The article introduces the results of a semantic analysis of Uku Masing's (1909– 1985) early poetry (1926–1943). The metres analyzed are syllabic-accentual trochaic tetrameter, trochaic pentameter, iambic pentameter and dactylic, logaoedic and polymetric hexameters. In each text the textual communicative perspective as well as motifs and tropes of each verse line were examined. The semantic differences and colourings of the metres are most evident in the way of expression, in the viewpoint.

Hammering Home the Lesson Stomatopods are marine crustaceans that use hammerlike claws for defense and to attack their prey. The claws undergo repeated high-velocity and high-force impacts. Weaver et al. (p. 1275 ; see the Perspective by Tanner ) used a variety of techniques to examine the structure, mechanical behavior, and toughening mechanisms of the claw of the Peacock Mantis shrimp. The claw's composite structure is optimized for toughness, which helps to prevent the complete failure that might arise from the claw's repetitive hammering.

Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-27T11:26:22Z No. of bitstreams: 0Bitstream added on 2014-05-27T14:42:07Z : No. of bitstreams: 1 2-s2.0-80455168690.pdf: 1859569 bytes, checksum: 303873c72022368482fbca372fae657d (MD5) Made available in DSpace on 2014-05-27T11:26:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-01-01 Deformities and abnormalities in crustaceans have been associated to genetic problem, which occurred during molt process, damage caused by ectobionts, predators or environmental stress caused by chemical wastes. Some crab specimens collected in the São Paulo littoral were found having body abnormalities. They belong to the following crab species: Callinectes ornatus (Ordway, 1863), Arenaeus cribrarius (Lamarck, 1818) and Leurocyclus tuberculosus (H. Milne Edwards; Lucas, 1843). Samplings were performed by trawling during July 2008, August and October 2009 at the Ubatuba region, São Paulo State, Brazil. Body abnormalities were verified in the cheliped dactyl (C. ornatus an adult male), carapace deformities (A. cribrarius an adult male) and abdominal alterations (C. ornatus an adult female; L. tuberculosus an adult male and an ovigerous female). The record and analysis of such occurrences can help in the distinction of natural or human impact caused alterations. In this way, the occurrence study of this kind of body alterations could provide tools in order to control unprotected environmental areas, as well as bring subsides to understand the unusual variations during the ontogeny of important species in the benthic community. Departamento de Zoologia Universidade Estadual Paulista Julio de Mesquita Filho, Botucatu, São Paulo Instituto Federal de Mato Grosso do Sul, 79640-280, Três Lagoas, Mato Grosso do Sul Centro Universitário do Planalto de Araxá, Araxá, Minas Gerais Departamento de Zoologia Universidade Estadual Paulista Julio de Mesquita Filho, Botucatu, São Paulo

A male snow crab ( Chionoecetes opilio ) with two extra fingers on the left chela was caught from Abashiri, Hokkaido, Japan. These extra fingers arose from the inner proximal portion of the original immovable finger. Morphology of these extra fingers is quite similar to those of the normal fixed finger of the propodus and the dact. The author hypothesizes that the two extra fingers on the present Chionoecetes opilio specimen occurred by hyper-typic regeneration of the wounded dactyl. Albeit probably rare, this male snow crab had two extra fingers on the left chela. Keywords: Chionoecetes opilio ; extra fingers; immovable finger; left chela; male snow crab; morphology; wounded dactyl

The poetical corpus of 11th-c. Christopher Mitylenaios, such as it is found in manuscript No. Z alpha XXIX (13th c.) of the Biblioteca della Badia Great in Grottaferrata, consists of 145 poems and 2856 verses. Of these carmina 123 are written in jambic trimeters, 18 in dactylic hexameters, three in elegiac distichs, and one in an Anacreontic metre. In the first part of the article outer metric is discussed; among other things one learns that the Anacreontic poem 75 forms metrically a case of its own as it consists of eight strophes of four verses each, whereby the even strophes are followed by two so-called koukottllia, that the dactylic hexameters use 28 out of 32 possible schemes, thus contrasting with the Callimachean and Nonnian types, and that in the dodecasyllables the so-called Binnenschluss after the 5th foot is overwhelmingly present while in no less than 16 hexameters the poet uses a caesura after the 3rd foot. In the second part (inner metric) the numerous transgressions of metrical laws are investigated, as well as verse end and accentuation, and prosody; this last item concerns long and short vowels, diphthongs and dichrona, correptio Attica and hiatus. The text ends with a twofold appendix about caesurae.

A new species of marine hermit crabs, Dardanus holthuisi sp. nov., is described from New Caledonia and Vanuatu. This is one of the few species of Dardanus that live at depths of more than 100 m. This new species resembles Dardanus gemmatus (H. Milne Edwards, 1848) and Dardanus impressus (De Haan, 1849), but is easily distinguished from those two species by larger spiniform tubercles on the chelipeds, longer and more slender dactyl of the second and third pereopods, shorter ocular peduncles, and red colour on the fixed finger and dactyl of the chelipeds, and the dactyl of the second and third pereopods which persist for several years in fixative. Hermit crabs of the genus Dardanus Paul'son, 1875 are generally large and are recognizable by their relatively stout ocular peduncles with large corneas. Keywords: Dardanus holthuisi ; Dardanus Paul'son

This paper deals with recognition in dependency of count of objects in the training data set. For the capture the fingers position is used the sensory glove 5DT Data Glove Ultra.We describe the computer software "Dactyl Teacher" for recognition characters of Dactyl alphabet. This software contains a feed forward neural network, which is used for character recognition. In experimental part we examined count of iterations to train the neural network in influence of count of hidden layers and of count of neurons in these hidden layers. We choose the sufficient combination of these parameters for our feed forward neural network. Next we examined the success of recognition in dependence of count of training objects in training data set.

Journal of the Marine Biological Association of the United Kingdom (2009), 89: 1353-1366 Copyright © Marine Biological Association of the United Kingdom 2009 Published online: 2009 DOI: 10.1017/S0025315409000083, peer-reviewed, The Magharees fishery (Brandon and Tralee Bays in south-west Ireland) is 495 sq.km in extent, the majority of this area ≤20 m in depth. Since 1981 it has been occupied by a directed spider crab fishery yielding in some years all of the national catch of Maja brachydactyla. Maximum recorded landings were 336 t in 1999 and effort has numbered up to 10,000 pots annually. Increasing fishing capacity and declining opportunities have accentuated fishing effort on spider crab. This paper describes a catch census undertaken in the fishing season of March to August inclusive, 2000–2007 and a mark–recapture experiment, 2005–2007. A method of ageing the adult moult by attributing a chronology to the rate of erosion of the claw on the dactyl is introduced. Males migrated longer distances, moved into the fishery on a wider trajectory and demonstrated greater wear on the claw than females. Recapture rate of males was twice that of females. The conduct of the fishery changed in its 26 years in existence. Landings became more concentrated in the earlier months of the year and the recent summer fishery was characterized by fewer male captures. Larger males were quickly removed and none >140 mm carapace length survived in the fishery longer than one year.

PLANETARY SCIENCESightings of asteroids with companions--the latest of them just reported on the Web--are convincing astronomers that such pairs are far from rare. The first direct proof that asteroids can have moons of their own came when the Galileo spacecraft flew by 56-kilometer Ida in 1993 and photographed tiny Dactyl, a 1.5-kilometer body orbiting about 100 kilometers away. Now astronomers observing from the ground have detected a 15-kilometer satellite orbiting about 1200 kilometers from the 214-kilometer asteroid Eugenia.

In Chile, amphipods of the genus Parhyalella Kunkel, 1910 (Amphipoda, Talitroidea, Dogielinotidae) have been assigned to Parhyalella ruffoi Lazo-Wasem and Gable, 2001 and recently have been used in macroalgal ecology studies. We show, however that these specimens belong to an undescribed species, that we describe herein as Parhyalella penai n. sp. This new species is characterised by a 4-conjointed article 1 of flagellum of antenna 1, bifurcate dactyl of gnathopod 1, width of article 6 of gnathopod 2 around 70% of its length and the presence of two distal spines in the peduncle of uropod 3. A new key to the genus Parhyalella is given.

The effects of cyclic electrical stimulation of the dactyl sensory nerve (DN) on the walking pattern of rock lobsters were examined at the two crucial points within the step cycle: the anterior extreme position (AEP) and the posterior extreme position (PEP). Stimulation during the occurrence of the PEP affected neither the movement pattern of the stimulated leg itself nor that of the ipsilateral adjacent legs. Stimulation of the same intensity during the occurrence of the AEP interrupted the oscillation of the stimulated leg and affected the phase relationships of the ipsilateral adjacent legs. The possibility that indirect influences were mediated by coupling to the substratum can be excluded. Neuronal connections may therefore exist between the funnel canal organs (FCO) of a single leg and the motor output of the adjacent legs. The discussion deals with whether the described channels alone are able to fulfil the requirements of a ‘coordinating mechanism’ as described in the literature.

This is the first comprehensive review of the genus Hyperoche since that of Bovallius (1889). This study is based primarily on the extensive collections of the ZMUC but also on more recent collections in other institutions. Seven valid species are recognised in this review, including one described as new to science. Two new characters were discovered; the first two pereonites are partially or wholly fused dorsally and the coxa of pereopod 7 is fused with the pereonite. These two new characters, combined with the knife-shaped carpus of the gnathopoda and the laminate mandibular molar, help to further distinguish this genus amongst the Hyperiidea. Partly as a result of establishing these distinctive characters, a new genus, Prohyperia gen. nov. is proposed for H. shihi Gasca, 2005 because it has characters not consistent with Hyperoche or the closely related genus Hyperia, to which it also bears some resemblance. Hyperoche medusarum and H. luetkenides, although morphologically similar, are considered separate species, with H. medusarum restricted to the colder waters of the northern Hemisphere and H. luetkenides to the Southern Ocean and Antarctic waters. Hyperoche cryptodactylus, still only known from the unique type, is considered a synonym of H. luetkenides because the character distinguishing it, the retractile dactyl of gnathopod 2, also occurs in some specimens of H. luetkenides and has also been found in other species of Hyperoche. Some specimens also have some pereopoda with partly or wholly retracted dactyls, although there is no pattern to the occurrence. In addition to the above the following species are also considered valid, H. martinezii, H. mediterranea and H. picta, found mainly in the tropical and temperate regions of the Atlantic and Pacific Oceans, and H. capucinus, restricted to the region between the Antarctic Polar Front and the Antarctic Continent. One new species, H. macrocephalus sp. nov., is described from the tropical eastern Indian Ocean and the Mediterranean Sea. All species are described and illustrated and a key is provided to facilitate their identification.

El endecasílabo anapéstico, dactílico o de gaita gallega ha sido utilizado en pocas ocasiones en la poesía española. El siguiente trabajo describe la existencia de un nuevo caso de endecasílabo anapéstico, dactílico o de gaita galleta en la obra del poeta cubano contemporáneo Rafael Almanza Alonso. Primero, se hace un recorrido por su poesía de juventud para demostrar su marcado interés por el empleo de este metro. Se estudia en particular el uso intencional o uniforme de la variedad dactílica del endecasílabo en el himno Iconos de este autor. Al comparar este himno con los textos poéticos hasta ahora documentados por la crítica que han usado esta variante del endecasílabo, se pretende demostrar que Iconos constituye el ejemplo de uso uniforme más extenso de este endecasílabo en la poesía lírica española. Por último, para su estudio, se sugiere utilizar el concepto teórico de verso variable de Oldřich Bělič.The dactylic hendecasyllable has been rarely used in Spanish poetry. The following paper describes the existence of a new case of the dactylic hendecasyllable in the work of contemporary Cuban poet Rafael Almanza Alonso. We will first study his youth poetry in order to demonstrate their strong interest in the use of the hendecasyllable. We will also document the intentional use of the dactylic hendecasyllable by this author in the hymn Iconos. By comparing this poem with the poetic texts that have used this variant of hendecasyllable, so far documented by critics, we aim to demonstrate that Iconos is the example of the largest and uniform use of this variety of hendecasyllable in the lyric Spanish poetry. Finally, we suggest to study this hendecasyllable by using the metric theoretic concept variable verse from Oldřich Bělič.

A well-known phenomenon in Finnish prosody is the alternation of binary and ternary feet. In native Finnish words, the primary stress falls on the first syllable. Secondary stress generally falls on every second syllable: (voi.mis).(te.li).(joi.ta) ’gymnasts’ creating a sequence of trochaic binary feet. However, secondary stress skips a light syllable that is followed by a heavy syllable. In (voi.mis.te).(lem.me) ’we are doing gymnastics’, the first foot is ternary, a dactyl.

The paper deals with the influence of the family factor (deaf or hearing parents) on the unknown text perception from hearing-impaired children. Special attention is paid to the understanding of the taught material through using of different communicative approaches for language education.

OBSERVATIONS of stellar occultations by asteroids have suggested that some may have satellites1. But given the absence of any confirmatory evidence, the prevailing view has been that although such satellites probably do exist, they are likely to be rare2. Here we report the discovery3 by the Galileo spacecraft of a satellite associated with the asteroid 243 Ida. Although the satellite, Dactyl, is only 1.6km across, it has been imaged with sufficient resolution for geological analysis. We describe the physical properties of Dactyl, with emphasis on its notably smooth shape, its crater population (which includes a crater chain) and its photometric properties. We find that, spectroscopically, Dactyl resembles both Ida and the other members of the Koronis asteroid family, implying a similar composition; small spectral differences may reflect a space weathering process that slightly alters the colours with time. We argue that Dactyl originated during the breakup of the Koronis parent body, and that satellites could be common around other asteroids (particularly members of asteroid families).

Anyone interested in keeping the stomatopod Odontodactylus scyllarus ( 1 ), commonly known as the peacock or harlequin mantis shrimp (see the first figure), will soon discover that these crustaceans should not be kept in glass aquaria. The force generated with the dactyl club—a 5-mm-wide appendage used by the shrimp to smash the shells of their prey—can reach 500 N, sufficient to fracture a glass aquarium wall. O. scyllarus , which is only 3 to 18 cm long, can apply these forces multiple times without damage to its own appendage. On page 1275 of this issue, Weaver et al. ( 2 ) investigate the structure of the dactyl club of O. scyllarus and show that it has a much higher specific strength and toughness than any synthetic composite material.

Riggia acuticaudata sp. nov. is described on the basis of 10 female specimens recovered from the body cavity of the freshwater catfish, Ancistrus sp. The fish were caught in a stream called the Corrego Piraputanga, a tributary of the Paraguai River. The new species differs from the others in the genus by being smaller and less convex and by having a pleotelson that tapers abruptly rather than being the same width throughout. Also, the pereopods and dactyls are much smaller, the maxillule has two terminal and three subterminal spines and the first two pleopods are elongate and acute. Additionally, R. acuticaudata sp. nov. is from a different Order of fish host and a new geographic area.

[1] On 28 August 1993 the Galileo spacecraft encountered the asteroid 243 Ida and its moon Dactyl. A variety of observations of this asteroid system were collected, including visible wavelength (0.4–1.0 μm) imagery with the Solid State Imager (SSI) instrument and infrared wavelength (0.7–5.2 μm) with the Near Infrared Mapping Spectrometer (NIMS) for both objects. These data indicate that 243 Ida has an orthopyroxene/(orthopyroxene + olivine) ratio of 0.35, a value consistent with that of LL chondrites. The ratio does not vary significantly for the portions of 243 Ida observed by the Galileo NIMS instrument. Asteroid 243 Ida is a SIV subtype of the S type asteroid population. Two very similar spectral units were identified in a combined SSI and NIMS spectral data set. The primary discriminator between the spectral units is a small difference in the amount of “red” slope. A larger “red” slope value corresponds to regions of 243 Ida where ejecta from the crater Azurra are present. Dactyl has a relatively deep absorption centered around 0.97 μm. This suggests that Dactyl has larger mineral grains on its surface in comparison to 243 Ida and thus was formed by a younger collision than that which formed 243 Ida.

Tanapseudes gutui, n. sp., is described from depths of 3-34 m off San Juan, Puerto Rico, and 4- 5 m off Goat Island, Tobago. Tanapseudes sinensis Bamber from Hong Kong waters is re-examined and determined to represent a junior synonym of the type species T. ormuzana B|cescu which was originally collected in the Straights of Hormuz off Iran. Tanapseudes gutui can be distinguished from T. ormuzana by several characters including details of the mouth parts, the presence of a reduced spiniform seta on the distotergal margin of the propodus of pereopod 1, pereonites 3-6 with rounded anterior margins, and a pleotelson lacking a mid-lateral lobe. A neotype is established for T. ormuzana based on a specimen collected from near the original type locality, and its mouth parts and pereopod 1 are illustrated. Largely based on the absence of a palp on the maxillule and the presence of a bifurcate seta on the dactyl of pereopod 1, the family Tanapseudidae B|cescu is now considered a subfamily within the family Kalliapseudidae Lang sensu GuUu. The genus Paradoxapseudes GuUu, formerly within the family Tanapseudidae sensu GuUu, is tentatively transferred to the family Apseudidae Leach.

See Chapter 3 and Figures 60, 62. Measured from its central axis, the total radius of the blueprint's shaft ( f - i ) is ca. 1.01 m, with differences of only 1.5 mm between the widths of the top and bottom measurements. The top of the shaft where the arc intersects the chord measures 84.3 cm +/−0.1 cm (this portion of the drawing is not preserved, hence the uncertainty of .8429–8431 m for the restoration). Vertically, the drawing divides into the .3128 m base shown at 1:1 scale, and the 1.1857 m distance to the top of the drawing at d65 shown at 1:16 scale, resulting in a total height of 1.4985 m. The reduced-scale portion above the base measures 1.1232 m up to the level of the intersection of the arc and chord at d61a. At this level, the horizontal line does not conform to the regular intervals of dactyls of 1.85 cm, appearing instead 1.25 cm above d61, which Haselberger suggests may represent 2/3 of a single dactyl. As Haselberger concludes, the drawn shaft's total height to this point is therefore 60 2/3 dactyls, roughly corresponding to the built shaft's height of 60 3/4 feet. The significance of this dimension becomes apparent in relation to the other dimensions within the drawing. As b , its relationship to e as the total height of the drawing from the bottom of the base to d65 is an integral 3:4 ratio: (1.123 m/3) × 4 = 1.4973 m, a negligible difference of −1.2 mm from 1.4985 m as measured in the drawing.

The present paper reports two new species of Glyphocrangon (Crustacea, Caridea, Glyphocrangonidae) collected respectively from the East China Sea and the Philippines. G. singularis sp. nov., from the East China Sea, is similar to G. fimbriata Komai & Takeuchi, 1994 with the presence of fringe of setae on dactyl of the third to fifth pereopods, but differs from G. fimbriata by the rostrum shape and the armature on the carapace; G. denticulata sp. nov., from the Philippines, is similar to G. pugnax De Man, 1918 with the entire anterior third carina, but differs from G. pugnax by armatures of the antennal scaphocerite and carapace, the lengths of rostrum and the spines of fifth abdominal somite, and the colouration of carapace.

Two specimens of an undescribed species of pontoniine shrimp of the genus Periclimenaeus Borradaile 1915 from Maui Island, Hawaiian Islands, are described and illustrated, raising to three the number of species known from the Hawaiian Islands. The new species is remarkable for the greatly reduced molar process and sharp lateral cutting edge on the major second pereiopod dactyl and most closely resembles P. tchesunovi Ďuris, 1990. Host animals not identified. Periclimenaeus devaneyi Bruce, 2010 also has its colouration described for the first time.

The Ida/Dactyl system is the first confirmed asteroid/satellite pair as well as the first family asteroid to be studied in detail by a spacecraft. We explore consequences for Ida of formation by disruption of the Koronis parent body. A significant flux of projectiles onto Ida in a few years following the formation of the family is found, based on models of the disruption of the Koronis parent body by Marzari et al. (Marzari, F., D. Davis, and V. Vanzani 1995. Icarus 113, 168–187). This flux generated craters at a rate much higher than the current crater production rate; however, the flux decreases rapidly as fragment orbits become randomized. Also, we compare the figure of Ida with figures of equilibrium fluid bodies and find that the interior of Ida is nearly stress-free and that Ida could be a rubble pile. Finally, collisional models predict that Dactyl would have been shattered several times in the past 2 billion years, the lower bound on Ida's age derived from its cratered surface. However, some of the ejecta from such disruptions would be trapped in orbit about Ida, subsequently reaccumulating into a satellite. This process could explain the rather regular shape of Dactyl as well as explaining how Dactyl now exists, given its short (compared with Ida's age) collisional disruption lifetime.

Dactyl was discovered in solid state imaging (SSI) data on February 17, 1994, during the long playback of approach images from the Galileo spacecraft's encounter with the asteroid 243 Ida. Forty-seven images of the Ida–Dactyl pair were obtained. A detailed search for other satellites was made. No confirmed detections were made, all other candidate features being consistent with radiation hits. We deduce a manifold of osculating two-body orbits that approximate Dactyl's motion over the observed orbital arc depending on the assumed mass of Ida. At the time of Galileo's encounter, Dactyl was found to be 85 km from the center of Ida, moving at ∼6 m·sec −1 in the same rection as Ida's retrograde spin. The inclination of its orbit is ∼172° in Ida's equatorial system (IAU definition). It was not possible to obtain a definitive orbit or measure of Ida's mass from the observed motion even though supplemental techniques (search for Dactyl's shadow on Ida, changes in angular diameter and brightness, and attempts to determine the spin of Dactyl) were explored. The influence of Ida's irregular gravitational field and solar perturbations on two-body motion are evaluated and found to be undetectable in the observed orbital arc. These effects may, however, strongly influence the motion over orbital time scales. Limits to the value of Ida's gravitation parameter, GM , are derived. A robust lower limit, GM > 0.0023 km 3 ·sec −2 , is obtained by requiring Dactyl's orbit to be bound. Hubble Space Telescope observations, which show no evidence of Dactyl on a hyperbolic orbit, excludes values of GM in the range 0.00216 GM 3 ·sec −2 . An upper limit, GM 3 ·sec −2 , deduced by requiring that the orbital motion has a long lifetime in a realistic approximation to Ida's gravitational field, is illustrated with numerical calculations. Ida's mass is therefore constrained to the range 4.2 ± 0.6 × 10 19 g, which, together with a volume of 16,100 ± 1900 km 3 (Thomas P. C., M. J. S. Belton, B. Carcich, C. R. Chapman, M. E. Davies, R. Sullivan, and J. Veverka 1996. Icarus 120, 20–32.) yields a bulk density of 2.6 ± 0.5 g·cm −3 (Belton, M. J. S., C. R. Chapman, P. C. Thomas, M. E. Davies, R. Greenberg, K. Klaasen, D. Byrnes, L. D'Amario, S. Synnott, T. V. Johnson, A. McEwen, W. Merline, D. R. Davis, J-M. Petit, A. Storrs, J. Veverka, and B. Zellner 1995. Nature 374, 785–788.).

The type species of Holothuriophilus Nauck, 1880, H. trapeziformis Nauck, 1880 is rediscovered in the type locality,Mazatlán, Sinaloa, Mexico and in a new locality, Zihuatanejo Bay, Guerrero, Mexico. The generic diagnostic features in-clude a smooth, transversally elongated carapace, that is broader than long, widest portion anterior to middle portion andwith a cristate anterolateral margin; basal antennal article lacking a conical protuberance; third maxilliped with fusedischium and merus, spoon-shaped dactyl larger than subtrapezoidal propodus which is subequal in length to the carpus;abdomen with six somites and free telson. Hosts recorded for H. trapeziformis include the holothurids Holothuria inornataSemper, 1868, H. lubrica Selenka, 1867 and H. kefersteini Selenka, 1867 (=Paraholothuria riojai Caso, 1964), however,only the former is herein confirmed. Holothuriophilus trapeziformis can be separated from its eastern Pacific congener H.pacificus (Poeppig, 1836) because the fingers of the chela meet when closed instead of leaving a gape as in the latter species.La especie tipo de Holothuriophilus Nauck, 1880, H. trapeziformis Nauck, 1880, fue redescubierta en la localidad tipo,Mazatlán, Sinaloa y en una nueva localidad, Zihuatanejo, Guerrero, México. Las características diagnósticas incluyen: ca-parazón transversalmente alargado, más ancho que largo, su mayor amplitud anterior a la parte media, liso, y con el mar-gen anterolateral cristado; artejo basal de la antena carece de una protuberancia cónica; tercer maxilipedio con el isquio ymero fusionado, dáctilo de forma acucharado, más largo que el subtrapezoidal propodio el cual es subigual en longitud alcarpo, y el abdomen de seis somitos y telson libre. Los huéspedes registrados para esta especie incluyen a Holothuria in-ornata Semper, 1868, H. lubrica Selenka, 1867 y H. kefersteini Selenka, 1867 (=Paraholothuria riojai Caso, 1964), perosólo la primer especie es aquí confirmada. Holothuriophilus trapeziformis puede ser separado de su congénere del Pacíficooriental, H. pacificus (Poeppig, 1836), debido a que los dedos de la quela se juntan al cerrarse en vez de dejar una abertura como en la última especie.

Fallicambarus (F.) wallsi is described from San Augustine and Sabine counties, Texas. It may be distinguished from its nearest relative, F. (F.) kountzeae, by its distomesially oriented proximal margin of the cheliped's palm mesial to the condyle; proportionately longer mesial margin of the palm; lack of a distinct excision on the dactyl's opposable margin; more strongly tapering mesial process and absent or reduced cephalic process of the first pleopod of the first form male; and proportionately broader mesial ramus of the uropod, antennal scale and areola. An identification key is provided for the subgenus Fallicambarus.

Fourakis and Monahan [J. Linguist. (1988)] examined the effects of two different types of metrical foot (iamb and anapest) on syllable timing in 3 ft utterances. These utterances were comprised of three iambs, three anapests, and every possible combination of the two types. The present research follows the same paradigm but uses trochees and dactyls instead of iambs and anapests. A set of eight 3 ft long sentences was constructed. At one end there was the three trochee sentence: Auctions rescue business. At the other end was the three dactyl sentence: Auctions may rescue his businesses. The intermediate six sentences were formed by different combinations of the metrical feet. Five male and five female native speakers of Midwestern American English were recorded producing five repetitions of each sentence at a normal rate of speech. Segments were assigned syllable membership based on the maximum onset principle. Results will be presented on syllable durations as a function of foot type and sentence type. [Research supported by the University of Wisconsin Madison Graduate School.]

A new species of pontoniine shrimp, Periclimenes siankaanensis, is described from the Mexican Caribbean coast. The new species shares morphological features with P. patae Heard & Spotte,1991, P. antipathophilus Spotte, Heard & Bubucis, 1994, and P. mclellandi Heard & Spotte, 1997, all species belonging to the “iridescens” complex, and with P. platalea Holthuis, 1951, of the tropical east Atlantic. Periclimenes siankaanensis differs from P. patae and P. mclellandi by its large size, pereopods 3–5 with 2 or 3 spines on propodal inner margin and the presence of bifid dactyl, and is distinguished from P. antipathophilus by its smaller size, entire endite on the second maxilla, pereopods 2 of same shape, and by the lack of tooth on the movable finger. In addition, P. siankaanensis can be separated immediately from P. platalea by having the second pereopods equal in shape and length, and bifid dactyl present on pereopods 3–5. Periclimenes siankaanensis inhabits shallow water Thalassia testudinum seagra...

Rhythmic constraints have been notoriously hard to identify in speech timing. Appropriate experimental tasks may help in identifying grouping principles and timing constraints. In a baseline experiment, subjects read wordlists which contained eight trochees. They were instructed to read the words with regular timing. The inter–onset intervals obtained show evidence of a binary grouping into ‘‘feet’’ containing two words each, and of two‐word feet grouping into 4‐word super‐feet. Results were consistent with a hierarchical rhythm grouping of units into pairs, with the second element of each such group exhibiting some degree of deceleration or final lengthening. In a second condition, each word list contained 7 trochees and one (list medial) iamb. Inter–onset intervals suggest that a similar grouping takes place, with the stressed syllable of the iamb, rather than the first syllable, marking the onset of a unit. In a third condition, the iamb was preceded by a dactyl, giving a 4‐syllable foot. Again, results suggest that the stressed syllables, rather than word onsets, delimit production units. Together the results suggest that the stress foot is a unit which serves to structure speech in time.

Two chromatic morphs of Pagurus lanuginosus de Haan, 1849, of Imafuku and Ikeda (1995) are here recognized as 2 distinct species: the "black spot" morph is referred to true P. lanuginosus,and the "white spot" morph is described herein as a new species, P. maculosus. The range of P. maculosus appears restricted to the Pacific coast of the Japanese main islands from Boso Peninsula to Amakusa, Kyushu. Pagurus lanuginosus is considered to be more widely distributed in the Japanese main islands, Korea, and the Russian coast of the Sea of Japan. Within the range of the new species, P. lanuginosus sometimes occurs sympatrically. A neotype is designated for P. lanuginosus to establish its taxonomic status, since its type material is no longer extant. In addition to the coloration, these two species differ morphologically from each other in the number of calcareous teeth of the right cheliped dactyl and the presence or absence of an enlarged tubercle on the merus of the right cheliped.

Within the context of prosodic feature analysis, this essay discusses some German manifestations of hexameter verse from the late eighteenth to the mid-twentieth century. Samples of hexameters by seven German poets-Johann Heinrich Voss, Johann Wolfgang von Goethe, Friedrich von Schiller, Eduard Morike, Friedrich Hebbel, Thomas Mann, and Bertolt Brecht-are compared on both the metrical and the prosodic level of analysis. The metrical pattern for the German hexameter line allows for sixteen distinct line-types based solely on the distribution of syllables in nonprominent positions of the meter, and the data show that most poets favored certain line-types and tended to avoid others. Voss, Goethe, Schiller, and Hebbel, for example, favored line-types that begin with the configuration xoxoox (where x and o represent syllables in prominent and nonprominent positions, respectively), while Brecht preferred lines that are dactylic throughout, and Mann displayed no clear preference for any particular line-type. The data for the metrical configurations also reveal a strong similarity between the hexameters favored by Goethe and Hebbel, despite the fact that Hebbel's were written about sixty years after Goethe's. On the prosodic level, there are striking differences between the eighteenth- and nineteenth-century poets and the twentieth-century poets (i.e., Mann and Brecht). For example, compound words containing contiguous stressed syllables, which occur only rarely in hexameter verse by Goethe, Schiller, and Hebbel, were consistently used in the same metrical relation by other eighteenth- and nineteenth-century poets; Mann was inconsistent in his use of this word-type; and Brecht almost always placed it precisely in a metrical relation which the earlier poets invari- ably avoided. Among other things, Brecht's prosodic style is marked by the This essay is based in part on a paper presented at the Berkeley-Michigan Germanic

Decapod Crustacea display a slow metachronal rhythm of the third maxillipeds and pereiopod pairs one to four when undisturbed in the natural habitat. The dactyl tips are lifted off the substrate, and the unweighted limbs promote and remote at a slow frequency (range for all species 9–30min− 1). Movement is limited to the T-C joint. This behaviour, called waving, has been observed in many macrurans and an analogous activity, limited to the third maxillipeds, has been seen in several brachyurans. Analysis of EMGs shows: (a) the promotor activity increases in strength during a burst due to facilitation and motoneurone recruitment; (b) the rhythm period is stable throughout long waving sessions; (c) the promotor and remotor strokes are of equal duration and co-vary with period. Ipsilateral coupling is strong, with equal phases between adjacent limbs of 0· 05. The metachronal wave can pass anteriorly or posteriorly along an ipsilateral row. Bilateral coupling is weak. The two sides maintain equal frequency, and antiphasic coordination between the two ipsilateral sets of limbs is favoured. Possible functions for waving include gill grooming and supplementary gill ventilation. Comparisons between waving and other rhythmical motor programmes are discussed. Waving is an alternative programme for the walking legs, and is expressed when proprioceptive feedback is reduced.

The excitatory innervation of the claw closer muscle in the three larval (1st, 2nd, 3rd stage) and first postlarval (4th stage) forms of the lobster Homarus americanus was determined principally by electrophysiology. In the 3rd and 4th stages only two excitatory axons were found. One of these had a larger spike with a shorter latency and elicited a larger muscle EJP and a twitch-like closing of the dactyl compared to the other axon, which had a smaller spike with a longer latency and elicited smaller EJPs and a slow closing of the dactyl with repetitive stimulation. These two axons resemble, respectively, the fast and slow axons of the adult muscle. In the 2nd stage only two excitor axons were demonstrated, one of which resembled the fast axon in evoking large EJPs with regenerative responses. In the 1st stage, excitatory innervation is present, though the number and character of the axons remain unknown. Motor axons, therefore, innervate the claw closer muscle right from the time of hatching and are completely differentiated into fast and slow types by the end of the larval period of development.

The burrowing isopod Chiridotea coeca lives in medium to coarse sand. It preferentially burrows into sands of particle size ranges which most closely resemble its native substrate (particles sizes 250—1000 @sm), and burrowing is fastest in these substrates. Pereiopods and pleopods are fouled in substrates with particles smaller than100@tm. Locomotory rhythms above and below the substrate are similar. Phase differences between adjacent legs are 30% with metachronal waves moving forward. Power stroke for all pereiopods is by extension at the coxo-basal and basi-ischial articulations. Directions of leg thrust vary from almost perpendicular to the longitudinal body axis for gnathopods, to directly posterior for the last ambulatory leg. The body is dorso-ventrally flattened. Power and recovery stroke occur in very nearly the same plane and limb planes approach vertical posteriorly. Pereiopods lack the ventrally directed carpo-propodal flexure found in most free living isopods. Setae provide a conspicuous morphological adaptation to burrowing. Stout, posteriorly directed serrulate setae on the pereiopods increase the area of contact with sand grains, and provide an expanded tip around the dactyl. On the second and third gnathopods and all locomotory legs, a fringe of posteriorly directed plumose setae provides a shelter into which the leg behind can swing during recovery stroke. These setae increase in length and number with body size but the intersetal distance remains sufficiently close to exclude virtually all of the native sand grains from the spaces between the legs. Other morphological adaptations are discussed and the species is compared with other burrowing Peracarida.

Activities of individual, force-sensitive mechanoreceptors (funnel canal organs) of the terminal segment (dactyl) of the crab leg have been recorded in freely moving animals. During the stance phase of walking receptors discharge in regular bursts that are closely correlated with activity of the opener muscle of the propodite when the leg is used on the trailing side in lateral locomotion. Individual funnel canal organs also show sustained discharges to imposed cuticular strains and strains resulting from resisted muscle contractions. These receptors thus can monitor both internal and external forces that are applied to the leg in locomotion.

Alpheus inca, new species, is described from shallow rocky subtidal zones of Chile and Peru. This member of the macrocheles species group can be recognized by the locking notch of the dactyl in the palm of the major chela. The species lacks spines on the distal margins of the merus of the third pereiopods.

The American lobster, Homarus americanus which usually has dimorphic chelipeds consisting of a cutter and a crusher claw, occasionally has bilateral crusher claws. In these unusual lobsters however, only one of the paired claw behaves as a normal crusher claw. The other claw has only the appearance of a crusher claw but behaves as a cutter claw being able to close its dactyl completely in 20 msec and having short-sarcomere, fast fibers in its closer muscle. This suggests that claw morphology and closer muscle composition are not under rigid developmental control.

The shell-breaking behavior of the crabs Ozius verreauxii Saussure 1853 and Eriphia squamata , Stimpson 1859 from the Bay of Panama is described. The master claws of both these crabs are well designed for breaking shells. Small shells, relative to the size of a crab predator, are crushed by progressively breaking off larger segments of a shell's apex, while larger shells are peeled by inserting a large dactyl molar into the aperture of a shell and progressively chipping away the lip of the shell. Heavy gastropod shells are shown to be less vulnerable to crab predators than lighter shells, and narrow shell apertures and axial shell sculpture are demonstrated to be architectural features that deter crab predation. The incidence of architectural features which deter crab predation appears to be higher for smaller gastropod species than for larger gastropods which are too large for most crab predators. Large fish predators prey upon both gastropods and shell-crushing crabs. To avoid fish predators, both these prey groups seek refuge under rocks when covered by the tide. Fish predation thus appears to enforce a close sympatry between smaller gastropods and their crab predators.