Argopsis 2 while his figure of the crossection of a cephalodium suggests the cerebriform type. Zhalbruckner tried to reconcile the literature without a critical study of material of either species, resulting in misstatements such as citing A. megalospora from Kerguelen rather than from Campbell Island and stating that the eight small spores coalesce to form a degenerate brown mass. Fortunately the type of Stereocaulon Argus Tav.l. and a duplicate of the type collection of S. cymosum Crombie are present and fruiting in the Taylor Herbarium at the Boston Society of Natural History. The former specimen agrees with Th. Fries' description of Argopsis, the second with the description of A. Friesiana Müll. Arg. Both are similar in podetial characters and cephalodia to Stereocaulon ramulosum. S.Argus has a hyaline paratheciun and hypothecium, asci apparently not more than 2-spored, of which one early degenerates, leaving a single large muriform spore very similar to those of Lopadium, remaining hyaline until late, then becoming slightly yellowish brown, not the deep brown muriform spore of Rhizocarpon. S. cymosum has a brownish paratheciun (not carbonaceous in the apothecium sectioned), asci 4-8- spored; ascospores with three transverse septa and an occasional longi- tudinal or oblique septum, producing a few-celled muriform spore simi- lar to those in Collema sect. Blennthallia. Were it not for the ex- treme form of S.Argus, there is little to distinguish S.cymosum from from Stereocaulon where the sterile material was referred. Until more information is available, it is largely a matter of individual opinion whether the generic limits should be circumscribed to include only S.Argus or enlarged to include S. cymosum. I have adopted the latter course. Both species seem to be endemic to small areas, but it is possible that they have been referred to some variety of S. ramulosum