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1.
Summary Four new species of hystrignathid nematodes are described from the midgut caeca of Passalus unicornus (Coleoptera: Passalidae) from St. Lucia, West Indies. Artigasia horridospina n.sp. is differentiated from A. dispar van Waerebeke, 1973 by virtue of fewer rows of spines in the oesophageal region and in possessing lateral alae, and from A. insignia Travassos & Kloss, 1958 in the extent of the oesophageal spiens and in having the lateral alae commence more anteriorly. The first annule is also much shallower than that of A. insignia. Longior semialata n.sp. is differentiated from L. longicollis Travassos & Kloss, 1958 on body length, b ratio, egg size and the starting point of the lateral alae. Mentecle magnifica n.sp. differs from M. parvus Travassos & Kloss, 1958 in having the spines of the oesophageal region extending much further down the body and in having ridged eggs. It is also longer and relatively thinner. Paraxyo ensicrinatus n.sp. differs from P. monodelpho Travassos & Kloss, 1958 in having a proportionately longer tail. The spines in the oesophageal region also extend considerably further posteriorly than in P. monodelpho.Two types of male associated with the above nematodes are described and illustrated, but not assigned to females. Pulchrocephala? pulchrocephala Travassos, 1925 is redescribed from the gut of the mole-cricket Scapteriscus vicinus.Scanning electron micrographs of four of the described species are given and briefly discussed. ac]19801024  相似文献   

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From the Buschmann-Klippe-Formation, mainly considered as Late Precambrian in age until now, the ArchaeocyathaBuschmannia roeringi, n. gen., n. sp. is described. Based on this discovery, an Early Cambrian age for the Nama-group is assumed.  相似文献   

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The laminated sediments of the Lower Oligocene ‘Sieblos-Schichten’ (dysodile and kieselgur-sediments) contain many individuals of a naviculoid diatom species. Formerly this group of diatoms would have been classified without doubt as Navicula (section ‘Minusculae’). After splitting this extremely heterogeneous genus in Navicula sensu stricto and some other homogeneous genera, the pattern of structures of this fossil species does not correspond to any established genus. For that reason this form will be described as the generotype of a new genus Eolimna. Furthermore it became evident that some Recent species (assigned to Navicula) show the same pattern of structures as the new genus Eolimna (generotype: E. martinii) which represents one of the first naviculoid diatoms of limnic origin. The essential criteria of this genus are: comparatively small cells with narrow girdle; simple alveolated rib system; areolae with a hymen in approximately medium position between relatively large sized foramina outside and inside of the valve; a single row of more or less irregular arranged areolae in close position to each other, on one or several of the copulae. The differences to supposed related genera are discussed.  相似文献   

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Divisispiculimermis mirus n. gen., n. sp., a mermithid parasitizing larvae of Chironomus sp. in the Cajón o Grande Stream, Córdoba, Argentina, is described. The new genus differs from all other mermithid genera in having paired spicules which are separated and divided into proximal and distal sectors. The other diagnostic characters of the genus are medium size, nematodes with the cuticle appearing smooth (lacking cross fibers under the light microscope); head separated from the rest of the body by a slight constriction at the level of the amphids, six cephalic papillae, mouth papillae absent, mouth opening posterior to level of cephalic papillae; six hypodermal chords at midbody; weakly S-shaped vagina; postparasitic juvenile with a tail appendage.  相似文献   

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Bartolius pierrei n. g., n. sp. (Digenea: Gymnophallidae) is described from metacercariae and naturally and cultivated obtained adults from southern Argentina. The second intermediate host is Darina solenoides (King) (Bivalvia: Mactridae) and the definitive host is Larus dominicanus Lichtenstein (Aves: Laridae). The diagnostic characters are as follows: Body small, oval. Oral sucker without lateral projections, twice size of ventral sucker (except in young metacercariae). Caeca short (in adults), without dorsal diverticula. Ventral sucker in posterior third of body. Ventral pit absent. Seminal vesicle bipartite. Ovary post-testicular. Vitelline glands paired, compact, close to ventral sucker. Uterus in fore- and hindbody. Genital atrium tubular. Genital pore inconspicuous, close to anterior margin of ventral sucker. Excretory vesicle Y-shaped with very short stem. Excretory formula: 2[(2+2)+(2+2)]=16. Bartolius is distinguished from other genera of the Gymnophallidae by the post-testicular position of the ovary.  相似文献   

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Rotasaccus dentifer n. g. n. sp., a Devonian ophiocistioid (Echinodermata) from the eastern Rheinisches Schiefergebirge differs from other ophiocistioids in some extraordinary features: there is no plated theca but a body wall containing a continuous layer of wheellike micro-sclerites; instead of perradial plates there are 7 fragile swallow-like elements with oral furrow in each perradial row; the relatively small tube feet are not covered by scale plates but by microscopic sieve plates. The formerly unknown masticatory apparatus of ophiocistioids is shown inRotasaccus to be built in principle like an echinoid lantern. In the systematical part, some revision for the class ophiocistioidea is realized from these results and a new family, Rotasacciidae, is introduced.  相似文献   

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Systematic Parasitology - Previous phylogenetic analyses of the Acanthocephala have demonstrated that the families Rhadinorhynchidae Lühe, 1912 and Transvenidae Pichelin & Cribb, 2001...  相似文献   

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A completely perichondrally ossified endocranium of a generalized reprsentative of the Eubrachythoraci,Beyrichosteus radiatus n. g., n. sp., is described. The specimen shows a typical platybasie skull with widely separated nasal capsules like that of the mainly Early Devonian Dolichothoraci. This is contrary to the spezialized generaTapinosteus andPholidosteus from Wildungen, being previously often regarded as model for the endocranium of coccosteomorph arthrodires. However, characters of the orbit and the nasal capsule are more similar to other Eubrachythoraci than to those of Dolichothoraci and primitive Brachythoraci. Until now, there are not enough other examples of sufficiently preserved endocrania of brachythoracid arthrodires known for a phylogenetic analysis. Nevertheless, the observations made onBeyrichosteus are questioning the assignment of the Pholidosteidae to the Coccosteomorphi.  相似文献   

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The fore wing of the new genus and speciesMoltenia rieki of the order Hymenoptera, tentatively belonging to the family Xyelidae, is described from the Molteno Formation (Upper Triassic) of South Africa. This fossil is a representative from the early evolutionary history of this order and the oldest Hymenoptera from central Gondwanaland. However, the plesiomorphic characters in its wing venation do not allow a clear assignment to a recent subgroup of the Hymenoptera, although generally it can be assumed that the Xyelidae had a much higher diversity during the Triassic than today.  相似文献   

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In Opiliones, male genital morphology plays a key role in systematics and understanding the evolution of the group because functional modifications often outline higher taxonomic levels. In Nemastomatidae, different lateral stabilizing structures on the penial truncus cane developed independently. These wing-like protuberances serve as anchor points for two muscular tendons and are interpreted traditionally as generic characters. A newly discovered species from Monte Saccarello in the Ligurian Alps of North-western Italy is unique in providing anchor points as stabilizing parts of the distal truncus cane below the glans by short and narrow lateral folds. To place this unusual species within the Nemastomatidae one must re-evaluate the usefulness of male genital morphological and other characters used in the systematics of the family. The resulting phylogenetic framework is supplemented with available molecular genetic data. Based on both datasets, the creation of a new genus seems justified. Saccarella schilleri gen. n. sp. n. is subsequently described and further defined. The endemism and biogeography of the harvestmen fauna in the South-western Alps are discussed with respect to this enigmatic genus.  相似文献   

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Eine nèue foliikole Flechte (Pleurotrema epiphylla sp. n.) aus Zaïre (Zentral-Afrika) wird beschrieben. Die systematischen Beziehungen der neuen Art zu den anderenPleurotrema-Arten und die Stellung der GattungPleurotrema innerhalb der FamilieParatheliaceae wird kurz diskutiert.  相似文献   

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Cacatuocotyle paranaensis n. sp. (Dactylogyridae, Ancyrocephalinae) is described from the gills of the characid fishes Characidium lanei Travassos and C. pterostictum Gomes collected from two streams on the coast of the State of Paraná, Brazil. Cacatuocotyle n. g. is proposed for species possessing a single cephalic lobe (terminal), one pair of head organs, a convex haptor with thickened muscular anterior margins, one anchor-bar complex (ventral), seven pairs of ventral hooks (one pair associated with the anchor shafts; one central pair anterior to the bar; five submarginal bilateral pairs) and a sinistral vaginal aperture.  相似文献   

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