A new species Renicola glacialis sp. nov., belonging to the trematode genus Renicola, is described.

The species is distinguished from most other renicolids by its relatively large size. Two other species within this size range have been recorded; while it is easy to separate R. glacialis from one of these species (R. goliath Wright, 1957) the poor description of the other (R. secunda Skrjabin, 1924) renders a detailed comparison meaningless. However, the differences in host and geographic location between this and R. glacialis are considered sufficiently great to justify the erection of a new species.

The pathology of R. glacialis is discussed; recently established worms elicit only a slight host tissue response, but older infections are invested by a thick connective tissue sheath. The latter shows maximum development around dead worms and is accompanied by pronounced eosinophilia.

Attention has been drawn to the use of the excretory vesicle as a diagnostic character. Four distinctly different forms have been described, and it is suggested that this character, together with certain other morphological features, would provide a useful key for the identification of renicolids once such information is available.

Part of the cestode fauna of ten hyraxes captured in Kenya was studied.

The species of hyrax were Procavia habessinica Hemprich and Ehrenberg and Heterohyrax syriacus Schreber.

One hundred and five cestodes were fixed, stained, mounted and examined. Descriptions of specimens, including measurements, are recorded in text and figures.

The majority of third-stage Ostertagia circumcincta larvae exposed to 0·5% levamisole failed to infect lambs even though the worms regained some activity after repeated washings in balanced saline. A low level of efficiency was recorded against 4·5-day-old O. circumcincta when lambs were treated with levamisole at 7·5 mg per kg. Nine-day-old worms from hosts which received anthelmintic on day 4·5 were at the same stage of development as those from untreated control lambs.

Afromacroderoides lazerae gen. et. sp. nov. (Allocreadiidae; Walliniinae) is described and figured from specimens collected from the intestine of the African freshwater fish Clarias lazera from the White Nile near Khartoum, Sudan. The new genus is distinguished by the shape of its cirrus sac, the presence of a bipartite seminal vesicle and a spiny cirrus. It is differentiated from the related genera Paramacroderoides and Pseudoparamacroderoides.

The genus Ashworthius contains the following species: A. pattoni Le Roux, 1930 (genotype) from Tragelaphus scriptus sylvaticus (bush buck), A. sidemi Schulz, 1933 from Cervus nippon hortilorum (Sika deer) and C. elaphus asiaticus (red deer), A. martinagliai Ortlepp, 1935 from Bosclaphus tragocamelus (Nilgai) and A. lerouxi Diaouré, 1964 from Syncerus coffer nanus (dwarf forest buffalo). Pike (1969) revised the genus and redescribed A. lerouxi from Syncerus caffer coffer (African buffalo). He gave accounts of other valid species and amended the generic diagnosis.

1. Experiments were carried out to investigate the rapidity and duration of hatching of S. mansoni ova under simulated field conditions, using B. glabrata to detect miracidia hatching from infested faeces.

2. Hatching times varied according to consistency of the stool. Hatching started at 4 hours and ended at 32 hours for blended stools; started within 24 hours and ended within 48 hours for soft stools; and started at 32 hours and ended at 128 hours for hard stools.

3. Survival of B. glabrata was poor in the blended-stool experiments, but excellent in the soft-stool and hard-stool experiments.

During the spring, summer and autumn of 1967, 1968 and 1969, 109 rabbits were collected from two localities in Northumberland. Post mortem worm counts indicated that six species of helminths were present, Trichostrongylus retortaeformis, Passalurus ambiguus, Strongyloides papillosus, Nematodirus battus, N. filicollis and Cittotaenia denticulata.

T. retortaeformis was recovered from both localities, an overall infection rate of 88% being recorded.

P. ambiguus and C. denticulata were found at only one of the localities which would indicate that these species have a locally discontinuous distribution and an explanation for this has been discussed.

Both Nematodirus battus and N. filicollis which are normally sheep parasites were recorded for the first time from wild rabbits. The numbers of rabbits infected and size of infection were small and in consequence the rabbit can not be considered an important reservoir for these species.

138 wild duck of five species: Anas plalyrhynchos plalyrhynchos, A. penelope, A. crecca, A. acuta and Spatula clypeata taken in East Anglia, England were examined for trematodes, cestodes, nematodes and acanthocephala. Prevalence data are tabulated and maximum intensities recorded. The waterfowl were taken in the autumn and early winter and were presumed to be migrants coming in from western Europe.

Adult Dirofilaria roemeri were transplanted subcutaneously into two grey kangaroos and intraperitoneally into seven laboratory rats in an investigation of amicrofilaraemia, and for experimental transmission studies. Low level blood microfilaraemias of only short duration were produced in all but one rat, supporting the hypothesis that the grey kangaroo is an abnormal host of this parasite. Cortisone was instrumental in the success of D. roemeri in rats. Peritoneal lavage of rats harbouring transplanted D. roemeri proved an excellent source of microfilariae. Injection of large numbers of microfilariae into the saphenous veins of rats harbouring transplanted worms failed to alter the number of circulating microfilariae. D. roemeri failed to develop in Aedes aegypti, fed on rats harbouring transplanted worms and exhibiting blood microfilaraemia. One kangaroo, to which worms had been transplanted, was exposed to the bites of Dasybasis hebes (Diptera, Tabanidae) in the study area and acquired a natural infection of D. roemeri.

The route of migration and development of Ancylostoma ceylanicum, when given orally, has been described for the first time in hamsters. A predominant feature of the migration is the absence of any lung journey. This is unlike A. caninum, A. duodenale and A, brazilicnse when larvae are similarly given to an abnormal host. The larvae of A. ceylanicum apparently had no submucosal migration

Camallanus fotedari n.sp. is described from the intestine of Nemachilus from Kashmir. This is a new host record for the genus. The new species is characterised by the presence of 14–16 pairs of papillae of which 6–8 pairs are precloacal, 2 pairs are adcloacal and 6 pairs are postcloacal. The tail in females is rounded.

1. Two snail species (Physa marmorata and Drepanotrema surinamensis), guppies (Poecilia reticulata), and tadpoles (Bufo marinus) prevented in various degrees the infection of susceptible B. glabrata by miracidia of S. mansoni.

8. When the animal decoys were used in “pure” groups, the snails were more efficient in reducing the infection in B. glabrata than the guppies and the tadpoles.

3. When the animal decoys were used in “mixed” groups, the combination of P. marmorata and D. surinamensis was the most efficient group in reducing the infection in B. glabrata.

The catchment area of the Volta River covers an area of 153,000 sq. miles of which approximately 64,000 sq. miles is located in Ghana. This forms about 70 per cent of the total area of the country. Most of the catchment area in Ghana consists of savanna; including the Guinea savanna of the Northern region, the derived savanna of Northern Ashanti adjacent to it on the south, and the coastal savanna which is separated from the interior savanna by a broad belt of tropical forest. With the exception of some of the headwaters of the Afram the tropical forest is drained by smaller rivers including the Tano, Ankobra and the Pra which are not part of the Volta Basin. Most of the Volta catchment area lies in an area with a well defined wet season occurring between June and September.

In May 1964, the huge dam across the Volta River at Akosombo was completed and the dendritic Volta Lake began to form. It reached its full size after the rainy season of 1968 when it covered an area of approximately 3,275 sq. miles.

Four new species of digenetic trematodes of birds from Palawan Island, Philippines, are described: Galactosomum palawanense (Heterophyidae) from Ceyx r. rufidorsus; Euamphimeruspalawanensis (Opisthorchiidae) from Gallus g. gallus; Strigea palawanensis (Strigeidae) from Strix seluputo wiepkeni; Paramonostomum palawanense (Notocotylidae) from Centropus sinensis bubttlus. Stephanoprora sp. (Echinostomatidae) from Spilornis cheela palawanensis and Euamphimerus sp. from Chalcophaps i. indica are briefly described but not allocated to species as the specimens are incomplete.

The present study pertains to two nematode genera, Pungentus Thome & Swanger, 1936 and Discolaimoides Heyns, 1963 which were collected from around the roots of Juglens regia, the common walnut tree in Kashmir. They are described herein as new species. Discolaimoides is recorded here for the first time from India.

A survey of the helminths parasitising the gastro-intestinal tract of lambs in Northern Ireland is described. Twenty-four species were identified from the three hundred and seventy-two animals examined, which were drawn from abattoirs in different areas.

The major species found in the abomasum were Ostertagia circumcincta, 0. trifurcata, 0. pinnata and Trichosirongylus axei. Nematodints battus, N. filicollis, T. vitrinus and Cooperia curticei were the most prevalent species in the small intestine. Some observations are made on the relative incidence and role in the production of parasitic gastro-enteritis.

S. fernandoi and S. pillaii are described as new species and are shown to differ specifically from each other and from S. japonensis, the only other species that has been reported as having spines on the spicules.

Four methods of infecting hamsters with S. mattheei and S. haematobium were compared. The ring method was found to be the most efficient and the cercariae of both species penetrated in 10—20 minutes.

A comparison is made of the variations in the mean size (length), reduced weight, oxygen uptake, metabolic rate and the number of contained fully formed metacercariae undergoing autolysis, in mature daughter sporocysts of Microphallus pygmaeus, in sea water, artificial sea water and in a chemically defined nutrient medium (modified medium 199). The work indicates that the sporocysts begin to degenerate almost immediately in the non-nutrient media but have a higher metabolic activity and remain healthy for up to 36 days in the nutrient medium.

East African Fasciola gigantica apparently does not reach sexual maturity in mice, rats, hamsters, guinea pigs and rabbits. The order of recovery of flukes from the highest to the least was as follows : hamsters, guinea pigs, mice and rabbits. Rats were completely refractory to infection. The more highly susceptible animals also had a higher recovery rate of flukes. Mortality in animals appeared to be related to infection.