DESCRIPTION OF THE TETRASPORANGIAL CRUSTOSE AND GAMETANGIAL ERECT PHASES OF AHNFELTIOPSIS GIGARTINOIDES (J. AG.) SILVA ET DECEW (RHODOPHYTA, PHYLLOPHORACEAE) IN BAHIA DE BANDERAS, MEXICO

Tetrasporophyte and upright gametophyte thalli of a species collected in the region of Bahia de Banderas, Mexico are described. Both phases coincide with those observed in the life history of the genus Ahnfelti opsis Silva et DeCew (Phyllophoraceae, Rhodophyceae). Crustose thalli are not identifiable as any of the red crustose non-coralline algae pr eviously described, although they are similar to Erythrodermis Batters . The problems of identification of the specimens collected, which bea r a resemblance to three species reported in Mexico: Ahnfeltiopsis con cinna (J. Ag.) Silva et DeCew, Ahnfeltiopsis gigartinoides (J. Ag.) Si lva et DeCew and Ahnfeltia svensonii Taylor, are discussed. It is conc luded that the plants investigated should be assigned to Ahnfelfiopsis gigartinoides and that this is the only species of the genus present in the Mexican tropical Pacific.