•Eight species of scaled polychaetes are reported from hydrothermal vents of the Guaymas Basin in the Gulf of California; Neoleanira racemosa in the Sigalionidae and seven species of Polynoidae, including two new species, Bathykurila guaymasensis, in Macellicephalinae, and Macellicephaloides alvini, in Macellicephaloidinae. The latter genus and subfamily are reviewed, and a Key to the seven spe...