Abstract
A new erect, compressed species of Gracilaria (G. abbottiana sp. nov.) is described from the island of Oahu, Hawaii [USA]. It is the 1st compressed, and the 2nd truly intertidal, species of the genus to be reported from that island. In some respects the new species resembles 3 other compressed, generally nonproliferous species (G. incurvata Okamura, G. textorii (Sur.) J. Ag. and G. sublittoralis Yamada et Segawa) from the Pacific, and differs from them primarily by its smaller habit, morphology, anatomy or habitat.