The susceptibility of 13 different B. forskalii strains from Zaire, Cameroun, Gabon, Senegal, Rhodesia and Tanzania and B. reticulatus wrighti Aden has been tested to infection with Schistosoma intercalatum from Cameroun. The most common prepatent period was 23–28 days.

B. forskalii from Zaire, Cameroun and Gabon were excellent intermediate hosts with infection rates varying from 59–0 to 97–4% and with very low death rates, 0-28-4%. The strains from Senegal and Rhodesia had infection rates from 500 to 58.4%. B. forskalii from Tanzania was refractory. 53.0% of the exposed B. reticulatus wrighti was infected. The total cercariae production per snail varied from 1000–11000. The duration of the infection varied from 8 to 174 days.

A survey was carried out of the levels of infection with Aspiculuris tetraptera and Syphacia obvelata in a wild house mouse population living in the Charles Clore Small Mammals Pavilion at the London Zoo in Regent's Park. The extent of infection with A. tetraptera is analysed according to the sex of the host. It is shown that the prevalence of infection was greater in male than in female mice and frequency distribution studies suggest that this is not only because fewer female mice become infected but also because females resist larvae more effectively than do males.

Spirura hipposidcrosi n.sp. from the stomach of Hipposideros ruber resembles S. diplocyphos but differs in the head structure, the shape and size of the spicules, the position of the vulva and the presence of a tuft of spines in the male tail. Spirura nycterisi n.sp. from Nycteris thebaica and Hipposideros ruber resembles S. spinicaudata but differs in the presence of a membrane round the posterior half of the left spicule, the presence of a tuft of spines at the tip of the male tail, the position of the vulva and the size of the eggs. A key to the African species of Spirura is given.

Philometra kobuleji (Nematoda: Philometridae) is described as a new species from the abdominal cavity of a North American freshwater fish, Catostomits commersoni.

During a parasitological survey on stream fishes of Southern Ontario, males and females of a Philometra species were collected from white suckers, Catostomus commersoni (Laédpéde). This parasite differs from all known Philometra species recorded by Hoffman (1967) in North America.

Infective stage Brugia pahangi that were reared in Aedes aegypti survived equally well in cats that had previously been immunized against mosquito tissue and in a normal cat. The survival of third, fourth, juvenile, adult and microfilarial stages of B. paliangi that were recovered from cats was similar in jirds that had been immunized against cat antigens and in normal jirds. Host antigenic determinants were not detected on the surface of larvae in substantial amounts using fluorescent antibody techniques. It is unlikely that B. paliangi evades the immune response of its vertebrate hosts by masquerading as ‘self’ behind host antigens.

Ninety-seven cliff swallows, Petrocheilidon pyrrhonota, were examined from North-eastern Colorado. Five species of nematodes (Hadjelia pyrrhonotae sp. n., Acuaria sp., Microtetrameres inermis, Splendidofilaria sp., Diplotriaena sp.); four species of trematodes (Concinnum minor sp. n., Brachylecithum marinholutzi, Plagiorchis maculosus, Stomylotremagratiosus); and two species of acanthocephala.(Mediorhynchusgrandis, Mediorhynchus papillosus (juveniles)) were recovered. All eleven species of helminths represent new host records. Six new records (Hadjelia pyrrhonota, Microtetrameres inermis, Concinnum minor, Brachylecithum marinlwlutzi, Plagiorchis maculosus, Stomylotrema gratiosus) were established for Colorado. Five new records (Hadjelia pyrrhonota, Microtetrameres inermis, Concinnum minor, Brachylecithum marinlwlutzi were established for North America.

The pathology associated with the early migratory phase of infection by the sparganum larvae of Spirometra theileri (Baer, 1925) Opuni and Muller, 1974 (Pseudophyllidea: Diphyllobothriidae), has been investigated in TO strain mice and in rhesus monkeys (Macaca mulatto). All infected mice developed haemorrhagic skin lesions and oedema of the joints and often ascites and peritonitis 3–6 weeks after infection. There was a 25% mortality in mice given plerocercoids orally, 37.5% in those injected with procercoids intraperitoneally. From eight weeks after infection larvae in both mice and monkeys were at various stages of encapsulation. One monkey which died three weeks after oral infection with 100 procercoids had developed ascites, haemorrhagic lesions and an acute peritonitis; infarcts were observed in the liver, lungs and spleen.

Two new species of Calostraurus Sandars, 1957 (Cestoda: Davaineidae) are described from Australian marsupials, C. thylogale from Tliylogale biltardierii and C. mundayt from Potorous apicalis. A redefinition of the genus is given together with tabulated features of the species.

Egg excretion of S. mattheei was studied for about a year from man, baboons and cattle living in their normal environment. Although the excretory pattern was not unequivocal from man, there was a tendency of egg counts to decline with time: the baboons showed a seasonal pattern and the cattle a stable pattern throughout the year.