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A new species of the genus Thalassogenus Andrássy, 1973 is described and dedicated to the memory of Prof. Dr. M. Brzeski. It was extracted from Selaginella sp., La Paz Falls, Costa Rica. The main diagnostic feature is the long tail (108-178 µm, c’ = 2.6—4.3); also body length tends to be greater than in the other species (2.3-3.2 mm vs 1.7-2.5). Opinions vary with regard to the systematic position of the genus; Oncholaimina (Pelagonematidae) or Mononchina. We show that it belongs to Oncholaimina, where it represents a separate family. The genus is now known from four widely spaced regions in the tropics - India, New Guinea, Samoa Islands and Central America. The presence of an ocellus suggests that species of this genus are recent immigrants of freshwater.
The ostracode Lavachilina evae gen. et sp. nov. is described from the Arenig of Western Russia. Its carapace possesses a unique discontinuous velum, developed at both ends as a narrow spinose ridge. The systematic position of L. evae is uncertain. Its character set shows mostly palaeocope affinities but also some features of leiocopes. L. evae is tentatively assigned to the palaeocope family Oepikellidae, possibly representing an early member of that family. Although L. evae existed contemporaneously with palaeocopes such as Laccochilina, it does not appear to be closely related to these early eurychilinoids.
First and last instar larvae of Cistudinella obducta (Boheman, 1854) are described and figured in detail. Discussion on its taxonomic position and comparative data with other taxa of the tribe Physonotini are given. Structure of larva of Cistudinella suggest that it is not close to Physonota and its relatives and should be placed in the tribe Ischyrosonychini as was proposed earlier.
The profile structure of soils developed on the inpeatland dunes in the Biebrza River Valley and Narew River Valley suggested that they are rusty soils. However, the chemical analyses indicated the distinct accumulation of analyzed elements, mainly iron and aluminium, in the enrichment horizon (B). The determination of studied soils systematic position on the base of podzolic soil diagnostic criteria used by Systematics of Polish Soils and WRB classification as well as on the base of indicators proposed by various authors was the aim of the study. The results revealed that soils developed on dunes in the Biebrza River Valley can be determined as rusty soils, while on dunes located in the Narew River Valley, the podzol soils have developed. The absence of eluvial horizon in these soils presumably resulted from its mixing with humus horizon during ploughing in the past.
The placement of the tribe Gastropini within the subfamily Gymnomyzinae, with the tribe Gymnomyzini as a sister-group, is supported. Validity for two genera Gastrops Williston and Notacanthina Macquart (senior synonym of Beckeriella Williston) is maintained. Particular characters of their proboscis, ventral receptacle and the male terminalia are presented. A key to species and habitus photographs of selected species of Gastrops and Notacanthina are provided. The following new combinations are proposed: Notacanthina clypeata (Lizarralde de Grosso, 1986), comb, nov., A. fasciata (Mathis & Grimaldi, 2000), comb, nov., N. filipina (Lizarralde de Grosso, 1994), comb, nov., N. gigas (Lizarralde de Grosso, 1986), comb, nov., N. longiventris (Lizarralde de Grosso, 1990), comb, nov., N. maculata (Mathis & Grimaldi, 2000), comb, nov., N. magnicornis (Cresson, 1934), comb, nov., N. paragigas (Lizarralde de Grosso 1991a), comb. nov., N. parapendicornis (Lizarralde de Grosso, 1992), comb. nov., N.pendicornis (Cresson, 1934), comb. nov., N. pseudoclypeata (Lizarralde de Grosso, 1991), comb, nov., N. schildi (Cresson, 1934), comb. nov., N. wirthi (Lizarralde de Grosso, 1998), comb. nov. N. brasiliensis (Lizarralde de Grosso, 1998) is treated as an invalid name of N. wirthi (Lizarralde de Grosso, 1998).
Fragments of rhabdosomes isolated by chemical treatment from an erratic boulder of Baltic origin and ?Middle Ordovician age, provisionally assigned to Mastigograptus aff. tenuiramosus (Wallcott, 1881) were studied with SEM. Although exceptionally well preserved, remains lack the thin−walled free portions of thecae. Rhabdosomes are provided with a strongly developed basal disc, short stem and many branched stipes. The latter consist of heavily corticalized chains of stolothecae with alternately disposed thecal bases. Stolothecae display a morphological gradient and increase in size and change in shape distalwards. The stolon system studied with SEM on naturally and artificially broken specimens, as well as traced through open thecal bases, reveals a regular triad budding but no stolon inside the stolothecal cavity. We tentatively suggest that crassal lining, recognized earlier by TEM studies, corresponds to an unusually inflated stolonal stolon, filling the entire thecal cavity and adhering tightly to stolothecal wall. The systematic position of Mastigograptus, a matter of long debate, seems to be defined by a number of structural features which imply a distinct difference between genus in question and all known orders of sessile graptolites. The order Mastigograptida nov. and the family Mastigograptidae nov. are proposed.
A new planthopper Ptychogroehnia reducta gen. and sp. nov. from the Eocene Baltic amber is described. The new genus represents the fossil tribe Ptychoptilini Emeljanov, 1990 (Achilidae). The characters of the tribe and its possible bionomics are discussed.
Deilus fugax (Oliv.) was found in the Białowieża Primeval Forest (NE Poland). It is the northernmost locality of this species in Central Europe. Its geographic distribution is presented and discussed and a short information is given about systematic position, biology and ecology.
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