This paper reassesses the European and Macaronesian species of Nephroma, analyses their chemistry, and provides a key to the 14 species accepted. The investigation employs chemical techniques which enable even fragmentary material to be identified. Seven chemical groupings are recognized in the genus of which four occur in the species discussed here. Particular emphasis is placed on the distribution of major hopane triterpenoids within the genus. N. areolatum, N. foliolatum, N. hensseniae and N. sulcatum spp. nov. are described from Macaronesia, and N. tangeriense (Maheu & A. Gillet) Zahlbr., is accepted as distinct.

The epilithic lichen flora on the Beacon sandstone formation in Victoria Land consists of seven species: Acarospora gwynniiDodge & Rudolph, Buellia grisea Dodge & Baker, B. pallida Dodge & Baker, Carbonea capsulata (Dodge & Baker) Hale comb, nov., Lecanora fuscobrunnea Dodge & Baker, Leaded cancriformis Dodge & Baker, and L. siplei Dodge & Baker. The typification of the species is given along with descriptions and distribution in Antarctica.

The new species Lichinella japonica Harada & Henssen is described for the first time from Japan. L. japonica differs from known species in thallus structure and ecology. It is the first record of the genus from East Asia.

SEM observations of the surface of branch tips of Bryoria fuscescens, before and after treatment to remove the matrix produced by the cortical hyphae, are described. Cortical hyphae are arranged in a simple, apical bundle, parallel to the long axis of the branch, which becomes, behind the apex, a hollow cylinder containing the algal population. The cortical structure is less complex than that of Usnea subfloridana. Substantial amounts of extracellular matrix are produced and the significance of this is discussed.

The lichen vegetation on exposures of gabbro near Letterfrack, Co. Galway, western Ireland is described. Species abundance and vigour relate primarily to the geochemical composition of the gabbro substratum rather than to microclimatic factors. Lichens may be useful as geochemical indicators when mapping rocks with similar textures and mineralogies.