OBSERVATIONS ON RHINOMONAS RETICULATA COMB-NOV AND R-RETICULATA VAR ELENIANA VAR NOV (CRYPTOPHYCEAE), WITH COMMENTS ON THE GENERA PYRENOMONAS AND RHODOMONAS

Seven marine red strains of Cryptophyceae were examined using scanning and transmission electron microscopy. Six of these, possessing a nucleomorph housed within the pyrenoid and a periplast with distinctly hexagonal periplast areas, are assigned to Rhinomonas reticulata comb. nov. Rhinomonas reticulata var. eleniana var. nov. is described on the basis of the smaller size of the periplast areas. In a strain of the genus Pyrenomonas, which Rhinomonas otherwise resembles, the periplast areas appear more or less rectangular. Since it is impossible to know with certainty which red marine forms fall within the original concept of the genus Rhodomonas, the name Pyrenomonas should be preferred to a recent emendation of Rhodomonas.