Pseudoamallothrix paralaminata sp. n. is described from the Arctic Basin. The new species is very close to P. laminata (Farran, 1926) and O. profunda (Brodsky, 1950), but clearly differs from these in several characters of male and female. Xanthocalanus

Calanoid copepods are extremely successful inhabitants of marine, brackish and freshwater plankton. Morphological data are used to arrive at a first, parsimony-based phylogeny for the calanoid copepods. Each family is represented by at least one exemplar,

An analysis is made of the abundance, vertical occurrence and taxonomy of calanoid copepods from 29 samples. The samples were obtained in the northeast Atlantic between approximately 30° and 60°N and at intervals from the surface to a depth of 5000 m.