We describe here Magnapinna atlantica, a new species of oegopsid squid in the Magnapinnidae. This is the second described species in the family. The new species is based on two specimens, one of which is in excellent condition. This species has the following characters that are unique within the family: Tentacles more slender than adjacent arms, and proximal region of tentacles without suckers and bearing large glandular swellings. A third species is described but not named due to the poor condition of the squid. We also transfer Mastigoteuthis talismani to the Magnapinnidae, along with another squid, long known in the literature but incorrectly identified.