Revision of Navicula striolata (Grunow) Lange-Bertalot and N. rumaniensis Hustedt with the description of N. friedelhinziae sp. nov.

Navicula striolata was originally described as N. digitoradiata var. striolata from modern material collected in Sweden. After examination of a sample collected from Belgium, the variety was transferred to N. reinhardtii as N. reinhardti var. gracilior. From this time a large mix up of these and related taxa was observed in the literature. A similar species, Navicula rumaniensis had also been established in 1934 from Neogene Romanian materials but there has been much confusion regarding the status of these taxa, leading to a poor understanding of their distribution. In this study, type material of Navicula digitoradiata var. striolata, N. reinhardtii var. gracilior and N. rumaniensis are revised using light and scanning electron microscopy in order to clarify their identity and to investigate possible conspecificity. The results indicate that these species are not synonyms. Conspecificity of the modern N. digitoradiata var. striolata and N. reinhardti var. gracilior was confirmed and lectotypes of both varieties have been designated whereas N. rumaniensis proved to be a separate species. In addition, the study of Neogene material from Bulgaria revealed the presence of a new Navicula taxon—N. friedelhinziae. The morphology of these and similar taxa is discussed

Revision of **Navicula striolata** (Grunow) Lange-Bertalot and N. rumaniensis Hustedt with the description of N. **friedelhinziae** sp nov.

Navicula striolata was originally described as N. digitoradiata var. striolata from modern material collected in Sweden. After examination of a sample collected from Belgium, the variety was transferred to N. reinhardtii as N. reinhardti var. gracilior. From this time a large mix up of these and related taxa was observed in the literature. A similar species, Navicula rumaniensis had also been established in 1934 from Neogene Romanian materials but there has been much confusion regarding the status of these taxa, leading to a poor understanding of their distribution. In this study, type material of Navicula digitoradiata var. striolata, N. reinhardtii var. gracilior and N. rumaniensis are revised using light and scanning electron microscopy in order to clarify their identity and to investigate possible conspecificity. The results indicate that these species are not synonyms. Conspecificity of the modern N. digitoradiata var. striolata and N. reinhardti var. gracilior was confirmed and lectotypes of both varieties have been designated whereas N. rumaniensis proved to be a separate species. In addition, the study of Neogene material from Bulgaria revealed the presence of a new Navicula taxon—N. friedelhinziae. The morphology of these and similar taxa is discussed

Genomic reconstruction of the SARS-CoV-2 epidemic in England

AbstractThe evolution of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus leads to new variants that warrant timely epidemiological characterization. Here we use the dense genomic surveillance data generated by the COVID-19 Genomics UK Consortium to reconstruct the dynamics of 71 different lineages in each of 315 English local authorities between September 2020 and June 2021. This analysis reveals a series of subepidemics that peaked in early autumn 2020, followed by a jump in transmissibility of the B.1.1.7/Alpha lineage. The Alpha variant grew when other lineages declined during the second national lockdown and regionally tiered restrictions between November and December 2020. A third more stringent national lockdown suppressed the Alpha variant and eliminated nearly all other lineages in early 2021. Yet a series of variants (most of which contained the spike E484K mutation) defied these trends and persisted at moderately increasing proportions. However, by accounting for sustained introductions, we found that the transmissibility of these variants is unlikely to have exceeded the transmissibility of the Alpha variant. Finally, B.1.617.2/Delta was repeatedly introduced in England and grew rapidly in early summer 2021, constituting approximately 98% of sampled SARS-CoV-2 genomes on 26 June 2021.</jats:p