The Porifera occurring at Alagoas State reefs (north-eastern Brazil) are still little-known, with few species listed and even fewer formally described. From a total of 48 species recorded from the state, only eight belong to the Poecilosclerida, including those (re)described in this study. Here we describe a new species, Mycale (Mycale) alagoana sp.nov., and redescribe two species: Lissodendoryx (Lissodendoryx) isodictyalis (Carter, 1882) and Mycale (Naviculina) diversisigmata Van Soest, 1984, both first formal redescriptions from the Southwestern Atlantic. Additionally, Mycale (Aegogropila) escarlatei Hajdu et al., 1995 is here reported from Alagoas for the first time, in discussing the difficulties inherent to recognition in the field of small crustose Mycalids with neatly reticulated surfaces.
faunistics; Lissodendoryx; coral reef; sandstone reef; taxonomy