The materials on which the following observations are based consist of three
lots of tapeworms, all collected from the red veld rat, Rattus (Aethomys) chrysophilus from different parts of the Transvaal. One rat sacrificed and examined by Mr. P.S. Visser of the Bilharzia Research Unit, Nelspruit, was caught at Kaapmuiden, Eastern Transvaal; it carried a massive infection of tapeworms consisting of about 60 specimens of the species first described below and about a dozen specimens of the second species. The specimens were in an excellent state of preservation and were fully extended. My thanks are due to Mr. Visser for the care taken in the collection and preservation of this material. In addition, the first described species was also collected from the same host but from the Pafuri area of the Kruger National Park by Mr. C.G. Coetzee of the Medical Ecology Centre, South African Department of Health. Mr. D.H.S. Davis, Chief of the same Centre provided me with some live red veld rats from the Roodepoort area; from one of these a single specimen of this species was also obtained. My thanks are also due to these gentlemen for their assistance. The specimens collected by Mr. Visser, on which the following descriptions are mostly based, were killed and fixed together so that any differences in shape and length of the worms or arrangement of internal organs cannot be due to different methods of killing and fixing. On examination at the laboratory the two species could be easily separated from each other by naked eye examination; the first described species was more opaque and shorter whereas the other was elongate and more transparent.