Abstract
Two new species of Xanthocalanus are reported from the New Zealand continental slope. The female and male of X. longispinus n. sp. is described as well as the female of X. stewarti n. sp. Aspects of X. fallax and X. minor from Norway are re‐described and illustrated where observations differed from previous descriptions. Females of the two new species are distinguished from all other Xanthocalanus by a combination of characteristics of the female leg 5. The terminal segment has 4 spines and the inner terminal spine is completely fused to its segment in both species but is straight in X. longispinus and bent outwards in X. stewarti . The inner lateral spine extends beyond the base of the outer terminal articulated spine in X . longispinus and as far as the base of the outer terminal articulated spine in X. stewarti . The coxal inner border spinules are large, stout and cover a wide area in X. longispinus and are small, pointed and cover a narrow area in X. stewarti . The male may be distinguished from other known males with a styliform right leg 5 because leg 5 does not extend beyond the caudal rami, there are a series of about 8 stiff spines, graded in size, on the distal border of the left exopod segment 2, and the antennule has ancestral segments X‐XV, XVI‐XVII fused on both sides as well as XXII‐XXIII on the right side. Brachycalanus is recorded for the first time from New Zealand waters, although the single, damaged, female specimen is illustrated but not named.