In the Chambezi-Luapula area of the Northern Province of Northern Rhodesia, 2,575 Africans were examined for intestinal helminths and 2,017 for urinary helminths. The examinations were carried out in situ in the native villages in widespread localities representing different topographical parts of the area.

The average infection rates of the helminthic infections found were as follows: hookworm, 52.2%; Strongyloides, 13.3%; Ascaris lumbricoides, 3.7%; Enterobius vermicularis, 0.85%; Trichuris trichiura, 0.3%; Trichostrongylus sp., 0.1%; Schistosoma haematobium, 14.7%; S. mansoni, 6.99%; Hymenolepis nana, 0.09%; H. diminuta, 0.04%; Taenia sp., 0.04%.

The survey revealed regions or foci of relatively high and relatively low incidence in the case of each of the major species. The relationship of this to topographical and other factors is discussed.

Examination of 459 Africans for Mf. bancrofti revealed three positives, but none of these had definitely contracted the infection in N. Rhodesia. Mf. Perstans was found in 5.4% of those examined; this infection is endemic in the country.

The nematodes described and figured in the following pages are specimens mounted in glycerine which were obtained in 1931 (5 males and 4 females) and in 1932 (one female) from pasture soil at Winches Farm, St. Albans. Unfortunately they were not closely examined in the living condition and it is therefore impossible to give any information about their appearance and movements when alive. The nine specimens obtained at the earlier date were passed on to the writer by Dr. D. O. Morgan (who at that time was on the staff of this Institute) and had been found by him whilst examining earthworms in connection with investigations on “gapes” in chickens and young starlings upon which he was engaged at that time, i.e. March, 1931. These worms, after being killed and fixed in weak formalin and processed through dilute glycerine, were finally mounted in glycerine but no detailed study of them was made until recently when, in the course of re-arranging the slide preparations of free-living nematodes, made during the course of several years, they called for identification. The single female worm obtained in April, 1932, was found on a slide along with specimens of Anguillulina agricola, Anguillulina dubia and a female of Teratocephalus terrestris, all of which had been obtained in a Baermann funnel extraction of a piece of turf taken from one of the meadows at Winches Farm.