Pleurosigma strigosum W. Smith is not a variety of P. angulatum (Quekett) W. Smith but a different species, as confirmed in SEM. This conclusion agrees with that of Hendey (1964), who typified the species. P. finmarchicumCleve in Cleve and Möller 1882 does not show specific differences from P. strigosum. This paper gives descriptions and criteria for differentiation for P. strigosum, P. acutum Norman ex Ralfs in Pritchard, P. latum Cleve in Cleve et Grunow and P. sabangi Meister, a species that is not restricted to tropical seas - hitherto its only record. The second record of P. sterrenburgii Stidolph, from a truly antipodal locality, also raises questions regarding its distribution.