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Nevillia
''Alcyna'' is a genus of sea snails, marine gastropod mollusks in the family Trochidae, the top snails. This genus was previously included in the family Phasianellidae. Description The minute shell is similar in form to ''Phasianella''. The aperture is ovate. The columella has a heavy callus, bearing near the base a strong curved denticle projecting into the aperture. The outer lip is simple. The imperforate shell is acutely ovate. The convex whorls are spirally lirate and longitudinally striate. The columella is callous, and toothed below. The outer lip is smooth or toothed within, and varicose exteriorly. Species Species within the genus ''Alcyna'' include: * ''Alcyna acia'' Cotton, 1948 * ''Alcyna australis'' Hedley, 1907 * ''Alcyna exigua'' (Gould, A.A., 1861) * ''Alcyna kingensis'' (Gabriel, 1956) * ''Alcyna lifuensis'' Melvill & Standen, 1896 * ''Alcyna lucida'' (H. Adams, 1868) * ''Alcyna ocellata'' A. Adams, 1860 * ''Alcyna subangulata'' Pease, 1861 ;The following ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alcyna
''Alcyna'' is a genus of sea snails, marine gastropod mollusks in the family Trochidae, the top snails. This genus was previously included in the family Phasianellidae. Description The minute shell is similar in form to ''Phasianella''. The aperture is ovate. The columella has a heavy callus, bearing near the base a strong curved denticle projecting into the aperture. The outer lip is simple. The imperforate shell is acutely ovate. The convex whorl A whorl ( or ) is an individual circle, oval, volution or equivalent in a whorled pattern, which consists of a spiral or multiple concentric objects (including circles, ovals and arcs). Whorls in nature File:Photograph and axial plane flo ...s are spirally lirate and longitudinally striate. The columella is callous, and toothed below. The outer lip is smooth or toothed within, and varicose exteriorly. Species Species within the genus ''Alcyna'' include: * '' Alcyna acia'' Cotton, 1948 * '' Alcyna australis'' Hedle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alcyna Lucida
''Alcyna lucida'', a species of sea snail, a marine gastropod mollusk in the family Trochidae.MolluscaBase (2018). Alcyna lucida (H. Adams, 1868) . Accessed through: World Register of Marine Species at: http://marinespecies.org/aphia.php?p=taxdetails&id=1023121 on 2018-08-30 Description The rather solid, imperforate. subpellucid shell is white, with subdistant spiral riblets, and very minute longitudinal striae. The five, convex whorl A whorl ( or ) is an individual circle, oval, volution or equivalent in a whorled pattern, which consists of a spiral or multiple concentric objects (including circles, ovals and arcs). Whorls in nature File:Photograph and axial plane flo ...s show an impressed suture. The columellar tooth and external varix are strong. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alcyna Subangulata
''Alcyna subangulata'' is a species of sea snail, a marine gastropod mollusk in the family Trochidae, the top snails.Bouchet, P. (2013). Alcyna subangulata Pease, 1861. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=719077 on 2014-01-07 Description The height of the shell attains 2½ mm, its diameter 1½ mm. The minute, rather solid, narrowly perforate shell has an ovate-turbinate shape. It is ornamented with raised spiral striae. The four whorls are depressed somewhat in the center. The body whorl is obtusely biangular with about four low spiral cords above the upper angle, two and a very weak third between the angles. The base of the shell contains numerous spirals. The outer lip is thickened externally with a swelling or varix. The umbilicus is rather large. The aperture is circular. The columella ends in a prominent tooth. The color is deep red, wtth oblique light red flames radiating from the suture. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lip (gastropod)
In the shell of gastropod mollusks (a snail shell), the lip is the free margin of the peristome (synonym: peritreme) or aperture (the opening) of the gastropod shell. In dextral (right-handed) shells (most snail shells are right-handed), the right side or outer side of the aperture is known as the outer lip (''labrum''). The left side of the aperture is known as the inner lip or columellar lip (''labium'') if there is a pronounced lip there. In those species where there is no pronounced lip, the part of the body whorl that adjoins the aperture is known as the parietal wall. The outer lip is usually thin and sharp in immature shells, and in some adults (e.g. the land snails '' Helicella'' and ''Bulimulus''). However, in some other land snails and in many marine species the outer lip is ''thickened'' (also called ''callused''), or ''reflected'' (turned outwards). In some other marine species it is curled inwards (''inflected''), as in the cowries such as '' Cypraea''. It can also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alcyna Ocellata
''Alcyna ocellata'' is a species of sea snail, a marine gastropod mollusk in the family Trochidae, the top snails.Rosenberg, G. (2012). ''Alcyna ocellata'' A. Adams, 1860. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=593740 on 2012-11-23 Description The shell grows to a length of 2 mm. The shell is smooth and imperforate. The whorls are slightly convex. They are pale crimson, the last encircled by ocellated spots. The columella terminates in a prominent acute denticle. The operculum is non-calcareous. Distribution This marine shell occurs off Japan, New Caledonia ) , anthem = "" , image_map = New Caledonia on the globe (small islands magnified) (Polynesia centered).svg , map_alt = Location of New Caledonia , map_caption = Location of New Caledonia , mapsize = 290px , subdivision_type = Sovereign st ... and Hawaii. References * Robertson, R. 1985. ''Archaeogastropod biology and the systematic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alcyna Kingensis
''Alcyna kingensis'', common name the King Island kelp shell, is a species of sea snail, a marine gastropod The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. T ... mollusk in the family Trochidae, the top snails.Marshall, B. (2013). Alcyna kingensis (Gabriel, 1956). Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=720350 on 2014-01-07 Description The size of the shell attains 3.5 mm. Distribution This marine species is endemic to Australia and occurs off Tasmania. References *Gabriel, C.J. 1956. ''Mollusca from southeast of King Island, Bass Strait''. Memoirs of the National Museum, Melbourne 22(4): 1-15 *Wilson, B. 1993. ''Australian Marine Shells. Prosobranch Gastropods''. Kallaroo, Western Australia : Odysse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alcyna Exigua
''Alcyna exigua'' is a species of sea snail, a marine gastropod mollusk in the family Trochidae, the top snails. Distribution This species occurs in the East China Sea References * Gould, A. A. 1861. Proc. Boston Soc. Nat. Hist. 8: 18. Smithsonian Institution: ''Elenchus exiguus'' exigua ''Exigua'' (synonym: ''Brassicicephalus'') is an extinct genus from a well-known class of fossil marine arthropods, the trilobites. It lived from 501 to 497 million years ago during the Dresbachian faunal stage of the late Cambrian Period. Exigu ... Gastropods described in 1861 {{Trochidae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alcyna Australis
''Alcyna australis'' is a species of sea snail, a marine gastropod mollusk in the family Trochidae, the top snails.Marshall, B. (2013). Alcyna australis Hedley, 1907. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=720349 on 2014-01-07 Description The size of the shell varies between 1.8 mm and 2.5 mm. The small shell has a broadly conical shape. The 4½ whorls are rounded and increase rapidly in size. Colour: adult whorls dull white, protoconch A protoconch (meaning first or earliest or original shell) is an embryonic or larval shell which occurs in some classes of molluscs, e.g., the initial chamber of an ammonite or the larval shell of a gastropod. In older texts it is also called ... dark purple. Sculpture: the base is ornamented with spaced spiral grooves. These occur, but fainter, on the penultimate whorl. The protoconch, embracing 2½ whorls, is more strongly spirally furrowed. The large a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alcyna Acia
''Alcyna acia'' is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Trochidae, the top snails.Bouchet, P. (2013). Alcyna acia Cotton, 1948. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=719076 on 2014-01-07 Description The size of the shell attains 3mm. Distribution This marine species is endemic to Australia and occurs off Southern Australia and West Australia. Environmental Conditions This marine species tends to live in places with a sea surface temperature of . References *Cotton, B.C. 1948. ''Southern Australian Gastropoda. Part 3''. Transactions of the Royal Society of South Australia 72(1): 30–32 *Wilson, B. 1993. ''Australian Marine Shells. Prosobranch Gastropods''. Kallaroo, Western Australia : Odyssey Publishing Vol. 1 408 pp. External linksTo World Register of Marine Species acia ''Couepia'' is a genus of flowering plants in the family Chrysobalan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whorl (mollusc)
A whorl is a single, complete 360° revolution or turn in the spiral growth of a mollusc shell. A spiral configuration of the shell is found in numerous gastropods, but it is also found in shelled cephalopods including '' Nautilus'', '' Spirula'' and the large extinct subclass of cephalopods known as the ammonites. A spiral shell can be visualized as consisting of a long conical tube, the growth of which is coiled into an overall helical or planispiral shape, for reasons of both strength and compactness. The number of whorls which exist in an adult shell of a particular species depends on mathematical factors in the geometric growth, as described in D'Arcy Wentworth Thompson's classic 1917 book '' On Growth and Form'', and by David Raup. The main factor is how rapidly the conical tube expands (or flares-out) over time. When the rate of expansion is low, such that each subsequent whorl is not that much wider than the previous one, then the adult shell has numerous whorl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alcyna Lifuensis
''Alcyna lifuensis'' is a species of sea snail, a marine gastropod mollusk in the family Trochidae, the top snails.Bouchet, P. (2012). ''Alcyna lifuensis'' Melvill & Standen, 1896. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=595813 on 2012-11-23 Description The height of the shell attains 1.75 mm, its diameter 1 mm. It is a brightly colored small, imperforate shell with five slightly swollen whorls. These are white with transverse interrupted red lines encircling it spirally. Around the periphery these lines are regularly interrupted, leaving equal white spaces. Below the suture on the body whorl The body whorl is part of the morphology of the shell in those gastropod mollusks that possess a coiled shell. The term is also sometimes used in a similar way to describe the shell of a cephalopod mollusk. In gastropods In gastropods, the b ... there are square white spaces left bare. The aperture ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. :E.g. '' Panthera leo'' (lion) and '' Panthera onca'' (jaguar) are two species within the genus ''Panthera''. ''Panthera'' is a genus within the family Felidae. The composition of a genus is determined by taxonomists. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: # monophyly – all descendants of an ancestral taxon are grouped together (i.e. phylogenetic analysis should c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
