FIGURES 35–39 in Three new Psammothidium species from lakes of Olympic and Cascade Mountains in Washington State, USA

FIGURES 35–39: Psammothidium lacustre sp. nov., SEM. Fig. 35. External view of raphe valve, Hidden Lake NOCA, sample ANSP WACA017. Fig. 36. Internal view of raphe valve, type material, sample ANSP WACA019. Fig. 37. Areolae on internal surface of raphe valve, type material, sample ANSP WACA019. Fig. 38. Internal view of rapheless valve, Hidden Lake NOCA, sample ANSP WACA017. Fig. 39. External view of rapheless valve, type material, sample ANSP WACA019. Scale bars = 1 µm