New or previously misunderstood species of Lithographa and Rimularia (Agyriaceae) from the southern subpolar region and western Canada

Lithographa serpentina Coppins & Fryday is newly described from Campbell Island (New Zealand), and is unique within its genus and order for having submuriform ascospores. Also newly described are Lithographa opegraphoides Coppins & Fryday from the Falkland Isles, Rimularia actinostoma Coppins & Fryday from Canada (British Columbia), and Rimularia austrolimborina Coppins & Fryday from southern Chile. The new combination Lithographa graphidioides (Cromb.) Imshaug ex Coppins & Fryday is made to accommodate the previously misunderstood Stigmatidium graphidioides Cromb. and the more recently described Lithographa subantarctica Hertel & Rambold. A key to all described species of Lithographa is provided.