Abstract
The present paper is a further instalment of the Reports on the Molteno Institute collection, of which Parts I–III, dealing with the Ascaridae, Heterakidae, Oxyuridae, Camallanidae, etc., were published in this Journal by Dr H. A. Baylis in 1923. The history of the collection has been dealt with by that writer, and the following report on the Trichostrongylidae and Strongylidae is presented in as nearly as possible the same form as that of the preceding parts, consisting of a list of determinations of the material, together with notes on the less well-known forms and full descriptions of the new species. As in Parts I–III, the numbers attached to each set of specimens are the serial numbers given to the original tubes at the Molteno Institute.