Arthopyrenia parolinii Beltr. is one of the few species of the lichen genus Arthopyrenia A. Massal. described by Italian authors of the XIX century, lacking type formal association. In this regard, the name Arthopyrenia parolinii is hereby lectotypified using a specimen stored in the lichen herbarium of A.B. Massalongo at VER. Additional original material was found only at M, while another specimen at MSNVE, labelled as Spermatodium parolinii, although referable to this species, should not be considered as original material. Arthopyrenia parolinii is among the least well-known species in the genus. Given the genus Arthopyrenia is still very poorly known, it is important to clarify the original material of the species and propose the lectotyping. The selected lectotype is the only sample among the analyzed ones reporting complete data on the locus classicus; it conforms to the characters described in the protologue and comes from the Herbarium Beltramini. Key words: A.B. Massalongo Herbarium, Beltramini, lectotype, lichen, nomenclature.