Taxonomy and morphology of Amorphomyces (Laboulbeniales)

A revision of Amorphomyces was carried out based on an examination of the a uthor's and type material. Detailed study of the development of the female thallus of Amorphomyces italicus revealed a small, lobate, free, external p rimary appendage. A free appendage appeared to be lacking in all other know n species of the genus. The generic circumscription of Amorphomyces is ther efore emended. The new species A. hernandoi, parasitizing the marine aleoch arid Diglotta mersa, is described from Portugal. Amorphomyces stipitatus an d A. trogophloei are synonymized with A. italicus. With additions and chang es, Amorphomyces currently includes ten species. All taxa are illustrated w ith photographs and line drawings, and a key for their determination is pro vided.