The members of the genus Falcaustra are mainly parasites of tortoises. Of the 17 species of Falcaustra described from Asia, only 2 are parasitic in amphibians. Baylis (1933), recorded 3 species of Falcaustra from Malayan tortoises and Balasingam (1961), recorded another from Testudo emys from Malaya. The present paper records for the first time 3 new species of Falcaustra from Malayan amphibians for which the following names are proposed: Falcaustra purchoni sp.nov., F. pahangi sp.nov. and F. dubia sp.nov.

Diphyllobothrium medium (Fahmy) the adult stage of which is found in the otter, Lutra lutra, is redescribed.

1. A six year old child living in Singapore was found to be infected with the cestode Bertiella studeri.

2. Apparent cure was affected by use of Dichlorophen.

1. The sera of 18 goats were investigated for the bilharzia complement fixation reaction, using as antigen alcoholic extract of the livers of snails (Planorbis exustus) infected with cercariae of S. spindale.

2. The sera of 5 out of 7 goats harbouring S. mattheei, and of 4 out of 4 goats exposed to alimentary infection with S. bovis yielded positive results, the range of complement fixation varying from 5 to 20 M.H.D.'s.

3. The sera of non-infected goats and of 3 goats exposed to infection with cercariae of S. mansoni from which these animals appear naturally immune, yielded negative reactions.

4. The complement fixation reaction with cercarial antigen (S. spindale) has now been applied to infestation with 3 human and 4 cattle schistosomes, and its group applicability to mammalian schistosomiasis may be regarded as proven.

During August, 1922, acting as an Honorary Parasitologist to the Zoological Society of London, I examined an Indian Cobra, the “Hamadryad” Naja bungarus, which died in the Society's gardens. A single trematode was found in the Gall bladder. It was living and active. A careful search for other examples of this trematode in the snake proved negative.

Peroxynitrite (ONOO-) is a cytotoxic anion, produced by interaction between nitric oxide and superoxide in vivo in some inflammatory cells. This study investigated its effects on Fasciola hepatica and Dicrocoelium dendriticum isolated from ovine livers and kept in bile at room temperature. Peroxynitrite was synthesized using a quenched flow reactor and assayed spectrophotometrically. It was applied at different concentrations (10-3.5 to 10-2.3 M) to the flukes kept in bile. The viability of the peroxynitrite-treated flukes was compared with a control group (n=5–7 per group). Control F. hepatica and D. dendriticum lived for 226±11 and 208±14 min, respectively. Life times were decreased by peroxynitrite at all concentrations used (P<0.001). At the highest concentration of peroxynitrite, F. hepatica and D. dendriticum lived only for 6.1±0.4 and 4.1±4.1±0.2 min, respectively. Correlation between peroxynitrite concentration and parasite viability was significant in the case of F. hepatica (r=-0.842; P=0.0035). A single application of peroxynitrite can decrease the life span of ovine liver flukes. A failure in the activation of hepatic macrophages in infected animals may lead to a decreased production of free radicals and, thus, peroxynitrite. Such a failure is likely to deprive the body of a defence tool against multicellular parasites.

Determinants of parasite species richness have been investigated in a host–parasite system comprising fish of the family Sparidae and their monogenean gill ectoparasites of the genus Lamellodiscus. This study was carried out on a small geographical scale in the northwestern Mediterranean Sea. Host phylogenetic relationships were taken into account by phylogenetic eigenvector regression which required the reconstruction of a phylogenetic tree for the sparid fish species using mtDNA sequences. Several ecological variables potentially acting on Lamellodiscus species richness were considered. Host body size and host migratory behaviour appeared to be the main determinants of parasite species richness in this system. It is concluded that structuring of monogenean communities is controlled more by ecological than evolutionary factors.

A new species of Creptotrematina Yamaguti, 1954 was collected from characid fishes, Astyanax fasciatus (Cuvier, 1819) and Astyanax lacustris Lucerna & Soares, 2016 from the Batalha River in the State of Sao Paulo, Brazil. The new species most closely resembles Creptotrematina aguirrepequenoi, but differs by the elongated shape of vitelline follicles, the extension of these follicles in the posterior end of body and the fact that they are not confluent. The morphological differences were confirmed through molecular data. Three specimens were sequenced, and molecular analyses were based on the internal transcribed spacers 2 and D1–D3 domains of the 28S ribosomal RNA gene. The obtained topologies showed the new species as a sister taxon of C. aguirrepequenoi, a species originally described from Astyanax mexicanus in Mexico, and later found in Astyanax aeneus in Costa Rica. Isolates of the new species are reciprocally monophyletic, and genetic distance values are similar to those observed in other species pairs within Allocreadiidae. These findings corroborate that the genus Creptotrematina is mostly a parasite of characids, and widely extended across the Americas, with representative species occurring between Argentina and northern Mexico.

Adult forms of members of the Callodistomidae always parasitize the gallbladder of freshwater fishes and occur in Africa and America. This study provides a description of a new South American species belonging in Prosthenhystera from the gallbladder of a characid fish (Bryconamericus ikaa), and ribosomal gene sequences (28S rDNA and ITS1-5.8S-ITS2) are used to demonstrate molecular differences between the new species and congeners as well as explore interrelationships among congeners. Additionally, the first cytological analysis is conducted for a member of the family to determine chromosome number and arrangement. Prosthenhystera gattii n. sp. most closely resembles Prosthenhystera caballeroi in morphology, but the vitellarium is more extensive reaching anterior to the caecal bifurcation in the new species and the uterus is confined to the hindbody in P. gattii n. sp., whereas it extends to the level of the pharynx in P. caballeroi. Also, the testes, cirrus sac, seminal receptacle and the ratio of body length to width are larger in P. gattii n. sp. Independent Bayesian inference analyses of 28S rDNA and ITS1-5.8S-ITS2 sequence fragments produced phylograms that showed P. gattii n. sp. is more similar to Prosthenhystera obesa + Prosthenhystera oonastica than P. caballeroi + two unidentified species of Prosthenhystera, but with poor posterior probability support for the node in the ITS1-5.8S-ITS2-based phylogram. Further, the genetic distance between P. oonastica and P. gattii n. sp. are the largest among Prosthenhystera spp. Cytological analysis revealed ten metacentric chromosomes, which is fewer than the 12–18 chromosomes present in species from the closely related Gorgoderidae.

A cornerstone in parasitology is why some species or populations are more parasitized than others. Here we examine the influence of host characteristics and habitat on parasite prevalence. We studied the helminths parasitizing the Pyrenean brook newt Calotriton asper (n= 167), paying special attention to the relationship between parasites and ecological factors such as habitat, sex, ontogeny, body size and age of the host. We detected two species of parasites, Megalobatrachonema terdentatum (Nematoda: Kathlaniidae) and Brachycoelium salamandrae (Trematoda: Brachycoeliidae), with a prevalence of 5.99% and 1.2%, respectively. Marginally significant differences were found in the prevalence between sexes, with females being more parasitized than males. The present results show significant differences in the body length of paedomorphic and metamorphic individuals, the former being smaller. Nevertheless, no significant correlations between parasite prevalence and either newt body length, ontogenetic stage or age were found. In comparison with other Salamandridae living in ponds, prevalence and diversity values were low. This may be due to a long hibernation period, the species' lotic habitat and its reophilous lifestyle, which probably do not allow for a high parasite load.

Two new species of Multiceps are described. M. macracantha n. sp. a parasite of the white rat in Rhodesia, is distinguished by the possession of very large hooks. M. otomys n. sp. from a mouse, Otomys erroratus in Pretoria; has fairly large hooks of a characteristic appearance and shape.

The fact that the large taeniid hook appears to develop from at least two centres of chitinization is noted.

Microfilariae of Onchocerca cervicalis were injected subcutaneously into jirds, Meriones unguiculatus. At 72 hours post-inoculation the microfilariae had redistributed and the distribution pattern remained stable for approximately 100 days. Live active microfilariae were recovered from jird skin 168 days post-inoculation.

Fifty nine per cent of the microfilariae recovered at 72 hours were from the skin of the tail and inguinal region. The inguinal region was the preferred site in male hosts and the tail in females, the difference in distribution being attributed to temperature differences in the inguinal region of the hosts. It is suggested that the microfilariae migrate along a thermal gradient rather than at random.

Field observations made in 1935 on a potato crop growing on what was thought to be potato sick land in Bedfordshire seemed to indicate that eelworm damage due to Heterodera schachtii was less pronounced where maize had been the previous crop than in other cases. As particulars of the history of this piece of ground were not available, detailed observations were not made, but it was decided that it might be valuable to carry out experiments with maize to determine whether this plant had any effect on eelworm cysts. Other members of the natural order Gramineae have been shown by Triffitt to stimulate the larvae of H. schachtii to hatch from the cysts, and it was thought that maize might have a similar effect.

Three new species of the genus Neodiplostomum Railliet, 1919 (Subgenus Neodiplostomum, Dubois, 1937) are described from avian hosts in Central Africa. They are N. (N.) berghaani from Terathopius ecaudata, N. (N.) prudhoei from Cuncuma vocifer vocifer and N. (N.) pseudogypsis from Pseudogyps africanus.

A note is added on Neodiplostomum canaliculatum (Nicoll, 1914) Dubois, 1937.

Asexual multiplication in Cysticercus pisifortnis (Bloch, 1780) was first described by Moniez (1880). This observation was refuted by Solomon (1934) as being “erroneous or descriptive of an isolated or abnormal phenomenon”. Several years later, Crusz (1948) confirmed the observations of Moniez (1880). Voge (1967) did not mention asexual reproduction in this species in her review on postembryonic development of cestodes.

Studies carried out by the writer during the past few years on various species of the genus Anguillulina, associated chiefly with the roots of grasses, have resulted in the-collection of numerous other species of soil nematodes including many representatives of the predatory genus Mononchus. Amongst these are specimens of Mononchus tridentatus de Man, 1876, M. brachyuris Bütschli, 1873, two species in which males as well as females are known, M. muscorum (Duj. 1945), M. punctatus Cobb, 1917, M. papillatus Bast., 1865 and M. minor Cobb, 1893; all species in which females only are known. Investigation of these forms has resulted not only in the discovery of facts concerning their feeding habits but also of certain interesting anatomical features which have hitherto remained incompletely elucidated in members of this genus.

A short historical study of this species is followed by a redescription from a male specimen which provides further details of head and bursa and of the structure of the spicules. The spicules are considered to be of considerable taxonomic importance at the generic level. The presence or absence of certain other significant morphological features is confirmed, for example, the presence of a cervical cuticular inflation and the absence of a gubernaculum. A new host and a new geographical locality are recorded. Finally some notes on the genera Troglostrongylus Vevers, 1923 and Bronchostrongylus Cameron, 1931 attempt to explain why the writer considers that the latter genus is superfluous and could be suppressed. A key to the species of the genus Troglostrongylus (sensu lato), a list of species and synonyms, and a bibliography are given. An amended generic diagnosis is proposed.

In 1985, the writer in collaboration with Prof. M. B. Mirza described Strongyloides from John's Sand-boa (Eryx johnii) in Aligarh and assigned it to S. stercoralis, creating for its reception a new variety, S. stercoralis var. eryxi.

During July and August, 1950, while examining certain snakes at Hyderabad for helminth parasites, the writer found that Strongyloides infection was very common in the Rat-snake. Ptyas (Zamenis) mucosus, for almost all the snakes examined were found infected. In light infections not more than a few, ten to fifteen worms, were obtained from a single host, but as many as 100 to 125 specimens were collected from heavily parasitized snakes. It was also observed that though they may be found throughout the length of the oesophagus and the intestine, the seat of heaviest infection is the duodenum of the host.

It seemed rather strange that one and the same species should parasitize a reptile as well as a mammal so a detailed study of the worm, both in its parasitic and free-living generations, was undertaken with a view to determining definitely whether, as previously believed, it is identical with the human worm Strongyloides stercoralis. As a result of this study the writer has come to the conclusion that the species infesting certain snakes in India is not identical with the human worm, S. stercoralis or any other species of the genus hitherto described.

The material comprises three complete male worms in good condition and some male fragments; there are no females.

The worms are small, cylindrical and greyish yellow in colour. The body is partially covered with spines.

An echinostome cercaria (? Cercaria spinifera La Valette, 1855) with 37 collar spines and paraoesophageal glands has been recorded for the first time in Britain from the gastropod Planorbarius corneus. The cercariae penetrate into and encyst in planarians. Observations made on cercariae during penetration indicate that the paraoesophageal glands are used to enter the body of the planarian and that the so-called penetration glands have some other function. Gastropod molluscs may also serve as second intermediate hosts, but there is evidence to indicate that anatomically similar cercariae from different host individuals vary in their second intermediate host preferences.