Syn.: Zwackhiomyces immersus (Arnold) Grube & Triebel.

Lichenicolous, on the thallus of Bacidia bagliettoana.

Belgium: - .

Luxembourg: Lorr.: RRR.

France: Mar.: RR.

The material of the study area might represent a distinct, undescribed species, as Z. socialis s.str. appears to be confined to Clauzadea species.

Lit.: L9: 39, Bouly de Lesdain (1914: 162), Grube & Hafellner (1990: 320), Vouaux (1913: 91).