Small copepods (<2.5 mm) with elongate-oval body. Cephalosome and 1st thoracic segment, as well as the 4th and 5th thoracic segments are fused (3 articulated segments in cephalothorax). Posterior corners of the last thoracic segment are rounded. Abdomen slender, 4-segmented in female, 5-segmented in male. Rostrum consists of 2 filaments. A1 does not reach the end of the caudal rami. A1 with 24 segments in female, less in male. Exopodites of P1-P4 3-segmented. Each segment of the exopodite of P1 with an outer spine. Endopodite 1-segmented with 5 setae in P1, 2-segmented in P2, 3-segmented in P3 and P4. No P5 in females. Male P5 uniramous, the left branch slightly longer than the right. The distal segment of the left P5 much shorter than the previous segment and bear a row of spinules and a long, slender, terminal spine. Segments of the right P5 taper distally.
Pseudocalanus acuspes (Giesbrecht, 1881), Pseudocalanus elongatus (Boeck, 1865), Pseudocalanus gracilis, Pseudocalanus major G. O. Sars, 1900, Pseudocalanus mimus Frost, 1989, Pseudocalanus minor, Pseudocalanus minutus (Krøyer, 1845), Pseudocalanus moultoni Frost, 1989, Pseudocalanus newmani Frost, 1989