本文報導台灣島內首次發現的四種淡水紅藻，它們分屬於串珠藻(Batrachospermumectocarpum Sirod 和B. moniliforme Roth)，紅索藻(Thorea ramosissima Bory)和胭脂藻(Hildenbranida rivularis (Liebm.) Breb)。此四種均分佈於中央山脈中、低海拔的山區溪流，棲地之水溫低，溶氧量高，屬於貧腐水或β-中腐水級的水域。不過，四藻種所棲習之水域水質略有不同，有的在酸性，有的在鹼性環境。本文除對此四藻種之形態、棲地、分佈等作敘述外，並將其棲地之水質環境作比較。

　　　　　Four species of freshwater rhodophytes are reported for the first time in Taiwan. They areBatrachospermum ectocarpum Sirod, B. moniliforme Roth, Thorea ramosissima Bory, andHildenbranida rivularis (Liebm.) Breb. The morphology, habitat, and geographical distribution ofthese species are described. All of these species are found in clear, cool, and well-aerated subalpinestreams in the central ridge of Taiwan. However, they inhabit in the streams with quite differentwater quality. A comparison between their inhabitations is done.