Search results for "genus"
showing 10 items of 755 documents
Redescription and systematic status of the Antarctic genusAbietinellaLevinsen, 1913 (Lafoeidae, Hydrozoa, Cnidaria)
2005
The Antarctic–Patagonian genus Abietinella, comprising two known species, Abietinella operculata (Jaderholm, 1903) and Abietinella grandis (Vanhoffen, 1910), is reviewed. The holotype of Abietinella operculata is fully redescribed, including morphometry and cnidome, unknown up to now. Its distinctive characters are the growth habit, hydrothecal shape and, most important, the presence of a dish‐shaped operculum attached to the adcauline side of the hydrothecal aperture. We corroborate its conspecificity with A. grandis and, therefore, the monotypic condition of Abietinella.
Species of Acryptolaria Norman, 1875 (Cnidaria: Hydrozoa) collected by US Antarctic and sub-Antarctic expeditions.
2020
Acryptolaria is a worldwide genus of deep-water benthic hydroids. The genus has relatively high species diversity, with 36 species described so far, yet most of them have been reported only occasionally. As a result, scientific knowledge of their ecology and distribution is scarce. Here I present the results of the study of species of Acryptolaria collected during several Antarctic and sub-Antarctic expeditions under the United States Antarctic Research Program between 1958 and 1986. Eight species were found in the collection (plus one determined to the genus level), with A. operculata having the highest occurrence. Acryptolaria flabellum is reported for the second time; the study also repr…
Species ofSchizotrichaAllman, 1883 (Cnidaria: Hydrozoa: Halopterididae) from US Antarctic expeditions with the description of two new species
2005
Twelve species of the genus Schizotricha Allman have been studied, two of which are new to science (Schizotricha heteromera sp. nov. and S. trinematotheca sp. nov.). The material studied was collected by several US Antarctic expeditions. Each new species is described and figured, the systematic position amongst allied species discussed and available data concerning autecology and geographical distribution given. The remaining 10 species are considered regarding diagnosis, autecology and geographical distribution. Finally, a general survey of the bathymetrical and biogeographical distribution of the known species of Schizotricha is given.
Species of Oswaldella Stechow, 1919 (Cnidaria, Hydrozoa) from recent antarctic expeditions with R.V. 'Polarstern', with the description of eight new …
1997
Twelve species of the genusOswaldellaStechow have been studied, eight of which are new to science [Oswaldella delicatasp. nov.,O. encarnaesp. nov.,O. garciacarrascosaisp. nov.,O. gracilissp. nov.,O. grandissp. nov.,O. incognitasp. nov.,O. obscurasp. nov.andO. rigidasp. nov.], originating from the Weddell Sea and collected by several antarctic expeditions with R.V.Polarstern. Each is described and figured, its systematic position is considered and current data concerning its autecology and geographical distribution are given. Finally, a comparative table is presented including the principal features of all known species of the genus.
<p><strong>Revision of the Antarctic species of <em>Halecium</em> Oken, 1815 (Cnidaria, Hydrozoa, Haleciidae)</strong>&…
2014
A revision of the known Antarctic species of the genus Halecium has been carried out, based on the study of both type and non-type material. For each species a list of synonyms, a diagnosis, a broad description (with the exception of the recently described H. frigidum and H. exaggeratum), a discussion of its relationship with other members of the genus, and an account of its autecological data are given. Thirteen Antarctic species of the genus, including H. pseudodelicatulum sp. nov. and H. pseudoincertus sp. nov., are considered valid. Halecium tubatum is considered as species inquirenda. Halecium ovatum and H. macrocaulus are considered to be junior synonyms of H. interpolatum and H. ince…
Breaking molds: Oswaldella laertesi, sp. nov., a unique Antarctic species of Oswaldella Stechow, 1919 (Cnidaria: Hydrozoa: Kirchenpaueriidae)
2007
A new species of the Antarctic genus Oswaldella Stechow is described and figured, and its position amongst the remaining species of the genus is discussed. The material was collected from the Ross Sea area (Antarctica) during the BioRoss survey of the western Ross Sea and Balleny Islands in 2004. Oswaldella laertesi, sp. nov., is unique amongst known species of the genus in having hydrocladia arranged in three longitudinal rows.
Miocene fossil cercopithecoids from Kenya
1986
Fossil cercopithecoid material from Ngeringerowa, Ngorora, and Nakali, dated at between 8.5 and 10.5 m.y., is described. The specimens are the only cercopithecoid remains dated between 15 and 6 m.y. from sub-Saharan Africa. The mandible of asmall colobine from Ngeringerowa (similar in size to Colobus verus) is assigned to a new genus and species, Microcolobus tugenensis. Unlike other colobine genera, the symphysis of Microcolobus lacks an inferior transverse torus. A colobine lower M1 or 2 from Nakali is longer and narrower than molars of M. tugenensis, indicating that it may belong to a distinct taxon. A P4 from Ngorora cannot be assigned confidently to subfamily, due to its unique metacon…
Deuring’s mass formula of a Mumford family
2015
We study the Newton polygon jumping locus of a Mumford family in char p p . Our main result says that, under a mild assumption on p p , the jumping locus consists of only supersingular points and its cardinality is equal to ( p r − 1 ) ( g − 1 ) (p^r-1)(g-1) , where r r is the degree of the defining field of the base curve of a Mumford family in char p p and g g is the genus of the curve. The underlying technique is the p p -adic Hodge theory.
Surfaces non-orientables de genre deux
1993
The existence of nonorientable complete minimal surface of genus two, one end and total curvature −2π(2n+3),n≥3 is proved in this paper.
Equidistribution and Counting of Rational Points in Completed Function Fields
2019
Let K be a (global) function field over Fq of genus g, let v be a (normalised discrete) valuation of K, let Kv be the associated completion of K, and let Rv be the affine function ring associated with v.