The first modern taxonomic classification of the species of Lepraria is presented. Chemistry is the most important character used to separate the morphologically similar, but distinct, sterile taxa. Nine species are recorded from the British Isles, of which L. eburnea and L. frigida are new to science. Lepraria nivalis is a new name for Crocynia murorum B. de Lesd., and L. caesioalba (B. de Lesd.) Laundon a new combination. Two species, L. incana (L.) Ach. and L. lobificans Nyl., are especially common and are dominant on shaded bark and rock. Twenty-eight lichens reported as Lepraria belong elsewhere or require further study. The combination Leproloma cacuminum (Massal.) Laundon is made to replace the name L. angardianum.

In support of the Lichen Flora of Great Britain and Ireland, 22 new combinations are made, and the following new species are described: Bacidia subcircumspecta Coppins, B. viridifarinosa Coppins & P. James, Coccotrema citrinescens P. James & Coppins, Eopyrenula avellanae Coppins, E. grandicula Coppins, E. septemseptata Coppins, Fuscidea hibernica P. James & Poelt, Graphis alboscripta Coppins & P. James, Lecidea doliiformis Coppins & P. James, Melaspilea atroides Coppins, Opegrapha fumosa Coppins & P. James, and O. multipuncta Coppins & P. James.

The lichenicolous coelomycete Stromatopogon baldwinii., forming galls on Usnea inTasmania and the Sandwich Islands, has a type of conidiogenesis not previously recognized amongst lichenized and lichenicolous fungi. Two different types of conidia, small simple microconidia and large submuriform macroconidia, are produced in the same conidioma, but in different regionsof the inner conidiomatal wall. The same kind of cells of the conidiomatal wall act as conidiogenous cells when macroconidia are produced, or give rise to elongated ramified conidiophoreswhen microconidia are produced.

The results of nitrogen (N) analyses of 14 New Zealand and 23 Antarctic lichens are reported. Eight percent of the total lichen N occurs in the form of amino sugars, 5° as nucleic acids and 80° as proteins and amino acids. It is concluded that when lichens decompose they may represent a good N resource that may be important in ecosystems.

A method using TLC to recognize compound patterns consisting almost entirely of chloroxanthones in European saxicolous species of Lecidella is described. These are necessary for diagnosis of the taxa studied and of their chemotypes. Two solvents with complementary separatingqualities were required: C, toluene-glacial acetic acid (100:15); J, dichloromethane-acetone (4:1). Although the Rf values in solvent J strongly depend on the concentration of the substances, it is very suitable for identification because the xanthones in this system reveal distinct and characteristic fluorescence colours in UV light, simplifying interpretation enormously. No spray reagents are used. Identifications are made by co-chromatography with authentic lichencompounds