The whole of the known fossil suid material from the Limeworks Quarry at Makapan is examined and described. Most of the specimens belong to the same species as the mandible described by Dale (1948) and named Pronotochoerus shawi. Reasons are given for concluding that the reference of this material to the genus Pronotochoerus is not correct. The specimens are considered to belong to the genus Potamochoeroides Dale, but to represent a species distinct from Potamochoeroides hypsodon Dale; they are therefore referred to Potamochoeroides shawi (Dale).
Diagnoses are given for the genus Potamocoeroides Dale and for the two species P. shawi (Dale) and P. hypsodon Dale.
The rest of the identifiable suid material from Makapan all belongs to Notochoerus euilus (Hopwood).
The process of third molar elaboration which has taken place in the evolution of the African Suidae is discussed and an attempt is made to assess the relationships of Potamochoeroides to other genera. The relationships of Notochoerus capevsis and N. euilus are also discussed and it is concluded that the differences in cusp pattern are sufficient to warrant a subgeneric division: Leakey's name Gerontochoerus is therefore revived as a subgenus and Notochoerus (Gerontochoerus) euilus is thus distinguished from Notochoerus (Notochoerus) capensis. The form described by van Hoepen & van Hoepen as Kolpochoerus sinuosus is considered to be a species distinct from, but closely related to, N. capensis and it is therefore referred to Notochoerus (Notochoerus) sinuosus (van Hoepen & van Hoepen).
The bearing of the suid fauna on the question of the probable date of the Makapan deposit is considered: it is concluded that the deposit belongs to the lower Pleistocene.
An attempt is made to estimate the age composition of the population of Potamochoeroides shawi and the possible influence on age composition of the manner in which bones have come to be included in a deposit is considered.