120 



ME.MOIRS OF THE XKW VOIIK BOTANICAL GARDEN 



PLATE 13 



Figure 18. Caloihrix conica 



Portion of a single filament, showing the apex 



and the base x 1,000 



19. Calothrix simplex 



Portion of a single filament, showing the apex 



and tlie base x 250 



20. Calothrix tenella 



Two typical young filaments x 500 



21. Calothrix linearis 



Portions of a typical filament, showing the base 



and apex x 500 



22. Calothrix. evanescens 



Two typical young filaments x 500 



23. Calothrix simulans 



Two typical filaments attached to the host x 500 



