The paper presents two saxicolous species of the family Megasporaceae, Aspicilia fluviatilis and Circinaria leprosescens, discovered as new to Poland. Aspicilia fluviatilis is a rare, arctic-alpine species with elongated marginal areoles, and Circinaria leprosescens, occurs only in marine and strongly nitrophilous habitats and is often found sterile with granular to isidiate upper cortex. The identity of C. leprosescens was confirmed by molecular data, BLAST searches and haplotype network analysis based on nucITS rDNA sequences. Aspicilia fluviatilis is also reported as new to Italy based on historical material from the Alps. Detailed information on morphology, chemistry, distribution and ecology are given for both species. Keywords: barcoding; biodiversity; haplotype network; lichen-forming fungi; taxonomy.