Abstract
Lagenidium chthamalpphilum described. The fungus invades barnacle ova from late gastrulation to emergence of nauplii. At 25-27[degree] C, in raw, aerated sea water at 36 parts/thousand salinity, the fungus is specific for lamellae of C. fragilis denticulata and will not invade lamellae of Balanus amphitrite, the associated barnacle.