A novel secondary metabolite, bastadin 15 [1], has been isolated from a temperate lanthella sp. The sponge also yielded four bastadins previously isolated from the tropical species lanthella basta. The bastadins, macrocyclic derivatives of bromotyrosine, were first isolated from the tropical verongid sponge lanthella hasta by Kazlauskas and coworkers (1,2), and later by Pordesimo and Schmitz (3). In the light of recent reports (4—6) of novel bastadins from this species, we present results from a temperate lanthella sp. collected at Pig Island, New South Wales. We here report isolation of a novel member of the group, bastadin 15 [1], and full characterization of the derivative tetramethylbastadin 15 [2]. Also present in this sponge are the known compounds bastadin 8 [3] and bastadin 12 [4}, here fully characterized for the first time (via the derivatives tetramethylbastadin 8 {5]and tetramethylbastadin 12 [6]), and bastadins 4 [7] and 6 [8]. [See Carney et al. (6) for a discussion on the numbering of bastadin metabolites.}