Foliicolous lichens from French Guiana (northeastern South America). Based on collections made by the author in 1995 at four localities (Nouragues, Saül, Paracou, Piste de St. Elie), 213 species of foliicolous lichens are reported from French Guiana. These include four species new to science: Byssoloma fuscothallinum Lücking sp.n., Mazosia uniseptata Lücking sp.n., Trichothelium confusum Lücking sp.n., and T. pallidum Lücking sp.n. In addition, the new combination Stigmidium concentricum (J. L. Bezerra & Cavalc.) Lücking comb.n. [bas.: Scutomyces concentricus J. L. Bezerra & Cavalc.] is proposed, and this taxon is suggested to be truely lichenized. Further seven species in the genera Actinoplaca, Aderkomyces, Aulaxina, Fellhanera, Kantvilasia, Mazosia, and Tricharia, are discussed as possibly new, but without formal descriptions due to the scanty material. A total of 136 taxa are new records for French Guiana, raising the number of foliicolous lichens known for this French overseas department to 224 and the total number of lichen species to 382. Five names are deleted from the checklist for French Guiana: Porina albicera (Kremp.) Overeem (possible misidentification of P. andreana), P. applanata Vain. (misidentification of P. pseudoapplanata), P. pseudofulvella Sérus. (= P. rufula), P. verruculosa Müll. Arg. (misidentification of P. guianensis f. pentaseptata) and Trichothelium alboatrum Vain. (misidentification of T. sipmanii). In terms of foliicolous lichens, about 70 of the species known from French Guiana are shared with Guyana, a similar percentage as is found in non-foliicolous taxa. It is assumed that this proportion will probably increase to about 90 when more data are becoming available. © ADAC / Elsevier, Paris