首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
2.
Bathycamptus eckmani gen. et spec. nov., which is associated with mudballs produced by the. cirratulid Tharyx luticastellus, is described from bathyal muds in San Diego Trough, off California. ?Heteropsyllus minutus Wells from the Haden Ground, Scotland is considered to be its closest relative and is placed in the same genus. The genera Bathycamptus and Psammocamptus Mielke are regarded as sister groups on the basis of the shared sexual dimorphism shown by P3-P4. Relationships with other marine Canthocamptidae are discussed, and a re-evaluation of the genus Hemimesochra Sars is made. It is concluded that this genus should encompass only the type species H. clavularis Sars. ?Leimia dubia Wells and H. nympha Por are transferred to the new genus Boreolimella, which is closely related to Bathycamptus but not to Leimia Willey. The genus Perucamptus gen. nov. is established to include H. rapiens Becker and shows no clear relationship with the other genera. H. trisetosa Coull is assigned to Caroliiaicola gen. nov., which is regarded as being an advanced member of the Paranannopidae. H. secunda Wells is recognised as belonging to Mesopsyllus Por; whilst H. nixe Por is considered the type species of a new genus Pusillargillus.  相似文献   

3.
4.
5.
Among the ascomycete isolates from soil and armadillo dung collected in São Paulo State, Brazil, a new species ofEmericella, E. montenegroi and a new variety ofE. rugulosa, E. rugulosa var.Iazulina are described and illustrated.Emericella montenegroi differs from the other known species of the genus in having ascospores with an incompletely reticulate or ribbed ornamentation on the convex walls.Emericella rugulosa var.Iazulina differs from the type variety in having blue to violet color of ascospores. Isolations ofE. corrugata andE. foveolata are also reported as a South American record. A synoptic key to all accepted species of the genus is provided.  相似文献   

6.
7.
Callipteris is a pantropical fern genus defined by two synapomorphies of its rhizome scales: 1) dark-castaneous to black borders, and 2) bifid marginal teeth. This monograph treats 15 neotropical species ofCallipteris that are further defined by the synapomorphy of anastomosing veins (free-veined species of the genus occur in the Neotropics and elsewhere). Three species are newly described here; the remaining 12 were previously classified inDiplazium. All the species ofCallipteris grow on wet forest floors at 100–2300 m. In the Neotropics the genus occurs from Guatemala to Bolivia, northern Brazil, and the Lesser Antilles. It has two centers of species richness. The first is the Chocó region on the western side of the Andes in Colombia and northwestern Ecuador. This region contains eight species, five of which are endemic. The second center is the mountains of Costa Rica and Panama, where six species occur, three of which are endemic. Only one species, an endemic, occurs in the Lesser Antilles in Martinique, St. Vincent, and Grenada. Four species occur only on the eastern side of the Andes, and these apparently represent at least two separate dispersal events from the western side of the Andes.  相似文献   

8.
Alnicola (=Naucoria, pro parte) is a mushroom genus of strictly temperate, obligately ectomycorrhizal species, traditionally included in the family Cortinariaceae. Most Alnicola spp. are primarily host specific on Alnus, although a few are mycobionts of Salix or other hosts. The different species of Alnicola exhibit unique morphological (cystidia, pileipellis) and cytological (dikaryotic or monokaryotic hyphae) characters. This makes the genus Alnicola of particular interest for studying the evolution of host specificity and morphological characters in ectomycorrhizal basidiomycetes. We used a combination of classical morphological and phylogenetic methods (rDNA ITS and LSU sequences) to address the following questions: (i) Is Alnicola monophyletic? And (ii) Are characters like host specificity or microscopical structures synapomorphic for certain clades? The study included nearly all currently known European Alnicola sp. Our results demonstrated that, on one hand, the genus Alnicola is polyphyletic, with sistergroup relationships to Hebeloma, Anamika or the clades /Hymenogaster I and /Hymenogaster II. On the other hand, Alnicola splits into three well-supported clades corresponding to the sections Alnicola, Submelinoides, and Salicicolae. The strict host-specificity to Alnus is a derived character and has occurred at least twice. The following morphological characters are synapomorphic for defined clades: the spindle-shaped hymenial cystidia for sect. Alnicola, the hymeniform pileipellis for sect. Submelinoides, and monocaryotic/clampless hyphae for sect. Salicicolae and its sistergroup /Hymenogaster II. As a taxonomical consequence, polyphyly of Alnicola implies that the sects. Submelinoides and Salicicolae need to be segregated from Alnicola.  相似文献   

9.
The wide distribution of the genus Ammosiphonia in the Upper Jurassic and Carboniferous of Western Siberia is established for the first time. Six haplophragmoidid species of Western Siberia are assigned to this genus. The diagnosis of the genus is emended; the taxonomic positions and scopes of the species Ammosiphonia nonioninoides (Reuss), A. beresoviensis (Bulatova), and A. sibirica (Zaspelova) are revised; two new species, A. suprajurassica sp. nov. and A. valanginica sp. nov., are described.  相似文献   

10.
11.
12.
13.
14.
15.
16.
This paper summarizes the current knowledge of unsaturated organic acids in their role as terminal electron acceptors for reductase chains of anaerobic bacteria. The mechanisms and enzyme systems involved in the reduction of fumarate by Escherichia coli, Wolinella succinogenes, and some species of the genus Shewanella are considered. Particular attention is given to reduction of the double bond of the unnatural compound methacrylate by the δ-proteobacterium Geobacter sulfurreducens AM-1. Soluble periplasmic flavocytochromes c, found in bacteria of the genera Shewanella and Geobacter, are involved in the hydrogenation of fumarate (in Shewanella species) and methacrylate (in G. sulfurreducens AM-1). In E. coli and W. succinogenes, fumarate is reduced in cytosol by membrane-bound fumarate reductases. The prospects for research into organic acid reduction at double bonds in bacteria are discussed.  相似文献   

17.
Turkish representatives of the genus Rhaponticoides Vaill. are examined. A key and distribution map of Rhaponticoides species occurring in Turkey are provided for the first time. R. hierroi Ö. Eren sp. nov., from Bakacak pass in the Western Taurus range, SW Anatolia, allied to R. mykalea (Hub.-Mor.) M. V. Agab. &; Greuter is described as a species new to science and illustrated. Its habitat conditions and conservation status are considered. Pollen micrographs of R. hierroi and R. mykalea are presented using scanning electron microscopy.  相似文献   

18.
The genus Rhizomastix contains five species of amoeboflagellates with a single anterior flagellum, which live as intestinal symbionts of insects and amphibians. Though established in 1911, Rhizomastix has been neglected for decades and its phylogenetic position is uncertain. This paper describes the morphology of the first cultivated strain of Rhizomastix. The organism was isolated from an argentine horned frog and differs from the known Rhizomastix species by the presence of biflagellate cells. The isolate is described as Rhizomastix biflagellata sp. nov. A possible relationship of Rhizomastix to Archamoebae is discussed.  相似文献   

19.
Keys for the identification of the presently known species of the genus Leptosagitta (fam. Sagittidae) are presented. Four new species of this genus found in shallow waters of Vostok Bay, Amursky Bay (Peter the Great Bay), and Kievka Bay (all of the Sea of Japan) are described in detail: L. kiyashkoi sp. n., L. latyshevi sp. n., L. magna sp. n., and L. pauca sp. n.  相似文献   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号