Various species of Harpellales. 11–13 Graminella microspora from Baetidae nymphs: 11 thallus overview, with inflated basal cell structures from which propagules arise or are extruded (note: one empty basal cell which has extruded its cellular content, arrow); young zygospores can also be observed (arrowhead) 12 a cluster of basal cells 13 fertile branch with a long series of minute trichospores; 14, 15 Harpella melusinae from Simuliidae larvae: 14 generative cells and allantoids or curved trichospores 15 basal cell and small conic holdfast 16 Legeriomyces ramosus from Baetidae nymphs, zygospores and zygosporophores. Scale bars: 25 μm in all figures.