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

.1. Infection with Diplostomulum phoxini is very common among minnows in the Glasgow area of Scotland.

2. The first intermediate host of the parasite in this area is shown to be the freshwater snail Lymnaea peregra.

3. Adult flukes were obtained experimentally in mice, ducklings and herring-gull chicks.

4. Significant differences are shown to occur between adult flukes recovered from different host species.

5. The implications of these findings in relation to the host specificity and the classification of the Strigeida are briefly discussed.

Two distinct Diplostomulum metacercariae were shown to inhabit the eyes of sticklebacks. Both these species could complete their life cycles in the same three host species. Observations at different seasons indicated that under cold winter conditions no transmission occurred from snails to fish in the field.

A collection of large marine nematodes made by the Zoological Survey of Pakistan in 1959 from the Arabian Sea at Karachi revealed the presence of a new species of the genus Leptosomatum, Family Leptosomatidae. Eight females, eighteen males, and several juveniles were obtained. The species is named Leptosomatum ranjhai in honour of Dr. A. R. Ranjha, Director of the Zoological Survey of Pakistan. The following description is based on eight females and ten males. All measurements were made on specimens after clearing in lactophenol. The means for the various measurements are given in brackets.

Drasche in Stossich established the genus Oxyspirura in 1897 for Cheilospirura cephaloptera Diesing 1861, previously described by Molin in 1800, along with two more species, all as belonging to Spiroptera. Since the establishment of this genus, as many as thirtysix species have been reported from various parts of the world. The distribution of this worm is very wide and the number of species seems to be much more than what has already been described. The writer collected nine species from the orbital cavities of birds, and all turned out to be new ones.

In 1931, Skrjabin divided the genus Oxyspirura into three subgenera, i.e. Oxyspirura, Cramispirura and Yorkeispirura, on the basis of the divided buccal capsule (Yorkeispirura) and undivided buccal capsules (Oxyspirura and Cramispirura); and also on the equal spicules (Cramispirura) and unequal spicules (Oxyspirura). The writer based the present key to the species of the genus on the same criteria. Species belonging to Yorkeispirura and Cramispirura are not included in this key.

Four samples of trematode parasites were collected from imported Abdim's storks at the Zoological gardens “Artis”, Amsterdam. The first collection was made during autopsy of a bird that had been in “Artis” for several years; some months later, the parasites were discovered in the oesophagus and mouth cavity of birds that were imported from Africa only recently. Ultimately, a number of trematodes belonging to the same species have been scraped out of the mouth cavities of 5 living Abdim's storks. My thanks are due to Mr. P. Zwart, veterinary surgeon, Utrecht, and to Dr. E. Jacobi, manager of “Artis”, Amsterdam, for collecting the parasites and making them available for taxonomic studies.

1. The gastro-intestinal tracts of 200 mink from 42 farms were examined for helminth parasites.

2. No parasites were found in the stomach but two species of fish-borne parasite were found in the intestine.

3. Evidence of infestation with the heterophyid trematode Cryptocotyle lingua was found in twelve mink, the largest number of flukes recovered from any one mink being seven.

4. Single immature specimens of the acanthocephalid Corynosonta hadweni were recovered from four mink, but it is considered that these were not instances of true parasitism.

5. It is concluded that helminth parasites do not constitute an important hazard on mink farms in Britain;

1. Six species of nematodes were recovered from Hertfordshire birds.

2. Porrocaecum ensicaudatum and Syngamus trachea are discussed, S. skrjabini El'perin, 1938 being considered a synonym of the latter.

3. The survey produced one new host record and two new records for this country.

During the survey 571 birds, representing 22 species were examined. Of the birds examined 396 (69·3%) were found to be infected with helminths, and of those infected birds 87. (21·9%) contained trematodes, 276 (69·7%) contained cestodes, 105 (26·5%) contained acanthocephala, and 146 (36·9%) contained nematodes.

Cestodes were found in 18 (81·8%) of the species of birds examined, nematodes in 10 (45·4%), trematodes in 9 (40·9%) and acanthocephala in 7 (31·7%).

The maximum helminth infections of all the bird species examined occurred in the spring. Nestling corvids, with one exception, were not infected with cestodes, but nestling turdids were heavily infected. Fledgling corvids also differed considerably as regards cestode infection. Magpies were 100% infected, jackdaws 35%, and rooks 20% infected.

Seven species of Echinostome cercariae are recorded from London ponds and rivers. Two of these, C. Z. Rees and C. echinoparyphii recurvati Mathias have already been described from other parts of Britain. The rest are new species. C. londonensis n.sp., C. deficipinnatum n.sp. are thirty-seven spined and C. essexensis n.sp. has forty-nine spines. C. hamptonensis n. sp., and C. thamesensis n. sp. are both large-tailed Echinostome cercariae, with twenty collar spines.

The possibility of using snails as second intermediate hosts by C. hamptonensis, a large-tailed Echinostome cercaria is shown to be highly improbable.

The classification of Echinostome cercariae is discussed.

Two new species of Gymnocephalous cercariae are described from London. Cercariae lophocerca Fil. is recorded for the first time from Britain. A description of this cercaria is given.

A species of Trichuris is described from domestic cats in the Bahama Islands, and identified as T. campanula. Previous descriptions of the two species of Trichuris in the domestic cat are summarised, and it is concluded that both are valid species.

The neotenic adult resembles the normal adult in general form, but is considerably smaller, varying between 1·4 and 3·5 mm. in length. The caudal disc bears three pairs of suckers, incompletely developed anchor hooks, and infrequently, persistent larval booklets (Fig. 7, l.h.).

Fine brown granules colour the intestine, and anteriorly four pigment spots mark the eyes. The gonopore (Fig. 7, gon.) is posteriorly placed, lying some distance behind the transverse level of the excretory openings. Vaginal prominences and copulation pores are absent.

It has been shown that guineapigs can be effectively protected against re-infection by the subcutaneous inoculation of embryonated Ascaris eggs (Soulsby, 1957). The purpose of this communication is to report a successful attempt to immunize guineapigs against a lethal oral challenge dose of eggs by the intravenous inoculation of third stage larvae of A. suum.

Three groups, each containing nine guineapigs, were infected with Ascaris as follows: Group I was given 10,000 eggs by mouth. Group II Was inoculated intravenously with 2,000 third stage Ascaris larvae which had been obtained from the lungs of other guineapigs on the sixth day of infection. Both groups were challenged at the same time with 250,000 eggs by mouth, along with a control group (Group III) which had no previous infection. The guineapigs in Group I were re-infected after 18 days and those in Group II after 12 days.