Two species of palaeacanthocephalan from Solea bleekeri from estuarine waters in Cape Province, South Africa, are described. Rhaidinorhynchus capensis sp. npv. differs from its closest relatives in having a smaller proboscis and in having body-spines arranged in a single field. Longicollum sp. innom., described from a single male specimen, differs from other species of the genus in having a basal row of large proboscis hooks and in having a recurved proboscis-sac.
The two species of palaeacanthocephalans described in this report were collected from Solea bleekeri Boulenger, 1898, in estuarine waters in the southern-most region of Cape Province and donated to the British Museum (Natural History) by Professor John H. Day of the Zoology Department, University of Cape Town. Co-infestations did not occur, nor were both species found in the same immediate geographical area. The coastal region of Cape Province, from Algoa Bay in the east, to Cape Agulhas or Cape Point in the west, constitutes, according to Ekman (1953), an independent zoogeographical province, and, therefore, data on the parasitic worms of the marine fish of this region, which at the moment are exceedingly meagre, may be of interest and importance as indicators of the affinities of the fish stocks inhabiting this area.