Over 70 species of Halichondria Fleming, 1828 are known world-wide, but only five from the Brazilian Coast. Brazilian records have their status re-evaluated here, and four new species are described for the São Sebastião Channel area, in the Tropical Southwestern Atlantic, viz. H. cebimarensis sp. n., H. sulfurea sp. n., H. migottea sp. n. and H. tenebrica sp. n.
Porifera; Halichondria; taxonomy; Brazilian coast; Southwestern Atlantic; new species