Observations of the genera Cylindrocystis (Meneghini), Mesotaenium (Näg.), and Spirotaenia (Bréb.), (=Palmogloea, Kütz. pro maxima parte) : mainly induced by a paper by J. Braxton Hicks, on the lower forms of Algae / by William Archer ; read before the Natural History Society of Dublin, May 5, 1865