In the present monograph of the coastal lichens, generally referred to as Dirina (crustose), Lobodirina (placoid), and Roccellina (suffruticose), two genera comprising 38 taxa are recognized: Dirina Fr. (7 species, 2 subspecies, and 4 forms) and Roccellina Darbish. (23 species and 2 forms). One Chiodecton and one Enterographa species are transferred to Dirina. Lobodirina Follm. is included in Roccellina together with seven species formerly placed in Dirina, one in Schismatomma, and one in Dirinastrum. The relationships between the two genera and the relation to other genera in Roccellaceae are discussed. Eleven species, and four forms are new: Dirina approximata Zahlbr. ssp. hioramii (B. de Lesd.) Tehler f. sorediala Tehler, D. catalinariae Hasse f. sorediala Tehler, D. insulana (C. Tav.) Tehler f. sorediala Tehler, Roccellina badia Tehler, R. cerebriformis (Mont.) Tehler f. sorediala Tehler, R. chalybea Tehler, R. conformis Tehler, R. exspectata Tehler, R. flavida Tehler, R. inaequabilis Tehler, R. nigricans Tehler, R. nigrocincta Tehler, R. obscura Tehler, R. suffruticosa Tehler, R. terrestris Tehler. Sixteen new combinations are proposed: D. approximata Zahlbr. ssp. africana (Fee) Tehler, D. approximata Zahlbr. ssp. hioramii (B. de Lesd.) Tehler, Dirina cretacea (Zahlbr.) Tehler, D. insulana (C. Tav.) Tehler, D. massiliensis Durteu et Mont. f. sorediala (Mull. Arg.) Tehler, Roccellina accedens (Nyl.) Tehler, R. capensis (Nyl. ex Stiz.) Tehler, R. cerebriformis (Mont.) Tehler, R. chilena (Dodge) Tehler, R. cinerea (Mull. Arg.) Tehler, R. cinerea (Mull. Arg.) Tehler f. sorediosa (Müll. Arg.) Tehler, R. falklandica (Zahlbr.) Tehler, R. limitata (Nyl.) Tehler, R. lutosa (Zahlbr.) Tehler, R. mahuiana (Follm.) Tehler, R. niponica (Nyl.) Tehler. All Dirina and 18 Roccelina species have been collected and studied in the field. Gross morphology and chemistry arediscussed. Statistical measurements of spore size are made for all species and subspecies. A cladistic relationship of the species of both genera, and a reduced area cladogram for Roccellina are proposed. Dirina is mainly restricted to the Northern Hemisphere and Roccellina, except for four species, is found in the Southern Hemisphere. The species are mainly bound to mediterranean, arid or subtropical climates.