Apiosordaria antarctica and Thielavia antarctica, two new ascomycetes from Antarctica.

Two new species of ascomycetes, Apiosordaria antarctica, isolated from soil, and Thielavia antarctica, isolated from a sample of the lichen Usnea cf. aurantio-atra, both collected on King George Island (Antarctica), are described and illustrated. Apiosordaria antarctica is characterized by ostiolate ascomata with agglutinated hairs, eight-spored, uniseriate and cylindrical asci, and two-celled, irregularly navicular ascospores, with an upper cell ornamented with very small warts and with an apical germ pore. Thielavia antarctica is characterized by nonostiolate ascomata, with a thick peridium, eight-spored, cylindrical asci, uniseriate, oblate, ovoid ascospores, a slightly protruding apical germ pore, and a phialidic anamorph.