The genus Ropalospora Massal. (lichenized Ascomycotina) is comprised offive species: R. lugubris (Sommerf ) Poelt in Hertel, R. atroumbrina (H. Magn.) S. Ekman comb. nova, R. hibernica (P. James & Poelt) Tonsb. comb. nova, R. chlorantha (Tuck.) S. Ekman comb. nova, and R. viridis (Tonsb.) Tonsb. Ropalospora is characterized by multiseptate acicular spores, presence of narrow, evenly thickened hyphae in the excipulum, and clavate asci with a tholus consisting of an inner amyloid zone surrounding the young spore mass, an outer amyloid zone along the inside of the ascus wall, and a less amyloid zone in between. A distinct ocular chamber is usually lacking. The presumably closely related genus Fuscidea Wirth & Vjzda differs in having asci that taper toward the top, a conoidal ocular chamber, and unevenly thickened excipular hyphae with ellipsoid or rectangular lumina. The typification, morphology, chemistry, ecology, and phytogeography of Ropalospora chlorantha, which has hitherto been referred to Bacidia, are treated. The additionalfour species of Ropalospora are discussed briefly. Within the circumscription of Zahlbruckner (1926-1927), which has persisted for a long time, Bacidia included the majority of crustose lichen spe- cies with biatorine or lecideine apothecia and spores with two or more transverse septa. Although widely accepted that Bacidia sensu Zahlbruckner is het- erogeneous (e.g., Hafellner 1984; Santesson 1952), a fair number of species unrelated to Bacidia in the strict sense are still referred to this genus. Bacidia chlorantha (Tuck.) Fink, which is rather common in some areas of eastern United States and Canada, is such a species. This became clear to me during my work with the North American species of Bacidia s.l. Harris (1977) already realized that B. chlorantha is unrelated to Bacidia in the strict sense. The purpose of this paper is to show that B. chlor- antha should be referred to Ropalospora Massal. Ropalospora chlorantha is treated in detail below, whereas the additional four species are concisely presented, mainly concentrating on characters thought to be relevant to the taxonomy of the genus. Furthermore, the position of the genus Ropalospora is discussed.