Climacosphenia elegantissima sp. nov., cont. GU52U-2 (A), GU52X-1 (B, C), GU44AI-5 culture (D), GU52AI-1 (E) A whole mount of frustule apical pole in girdle view, showing two girdle bands, patch of irregular areolae on the valve mantle (arrow), spines (arrowheads) B part of valvocopula broken away and showing a solid circular cross-section of the craticular bar (arrowhead) and well-developed fimbriae (arrow) C portion of valvocopula from stem, showing double craticular bars, ingrowths from opposite sides D apical pole with valvocopula showing porous bands of silica around several craticular bars E detail of copula showing stria density and fimbriate margin on pars interior. Scale bars: 10 µm (A, D, E); 5 µm (B, C).