1. Echinuria leiperi n.sp. and Echinuria singhi n.sp. are described from aquatic birds. A key to the species of the genus Echinuria is provided.

2. Skrjabinoclava alii n.sp. is described from Threskiornis melanocephalus.

3. Synhimantus hyderabadensis n.sp. and Synhimantus suraiyae n.sp. are described from Centropus sinensis and Urocissa flavirostris, respectively. Their relationship with the rest of the species of the genus is discussed. Synhimantus invaginatus (Linstow, 1901) Skrjabin, 1924, is reported for the first time from India and is redescribed.

4. Aliella anhingae gen. et sp. nov. is described from Anhinga melanogaster and is compared with the related genera of the family Acuariidae.

Six new nematode species of Dorylaimida are described from soil around roots of cotton plant in Uttar Pradesh, India : Discolaimium mazhari, D. upum, Aporcelaimellus heynsi, A. indicus, Leptonchus capitatus and Amphidelus novus. Keys to the species of the genera Discolaimium Thorne, 1939 and Aporcelaimellus Heyns, 1965 have also been provided.

Gongylonema thapari n.sp. is described from Gallus sonneratii. Its relationship with the other avian species of the genus Gongylonema is discussed. G. thapari differs essentially from the other species of the genus in having imbricated caudal alae.

G. congolense Fain, 1955 is reported for the first time from India. Structural variations within the species in 3 different avian hosts are noted.

It was found that with high level infections of Trichinella spiralis self-cure in immune mice occurs only slightly earlier than in normal mice. With low level infections self-cure is much earlier. In the host parasite combination studied the majority of the adult worms were found in the posterior part of the small intestine and no migration along the intestine was found. It is postulated that as migration is of such a variable occurrence it is not a necessary accompaniment to self-cure in T. spiralis infections. Where an early self-cure occurs it is obviously an important component of the immunity complex but other components such as reduced fecundity are equally important in limiting larval invasion of the muscles of immune mice.

Groups of breeding ewes were slaughtered at intervals before and after lambing in March. A post-parturient rise in egg count was observed in which Ostertagia spp. were dominant but in which other species took part, in particular Haemonchus contortus, Nematodirus battus and Chabertia ovina. The important contribution made by dormant larvae of Ostertagia spp. was confirmed but it was also found that reinfection greatly increased the number of worms present while the earliest part of the rise, often beginning prior to parturition, was probably due to the increased fecundity of adult worms already present. Adults of H. contortus present in ewes after lambing were derived from the maturation of dormant larvae and it is probable that the same applied to C. ovina. The close association of the postparturient rise with lactation rather than with pregnancy or parturition was shown and two possible explanations for this were discussed.

1. A precipitate was formed at the oral opening, excretory pore and anal opening of the fourth stage juveniles of O. columbianum in the presence of immune serum in vitro, causing their immobilisation and subsequent death in large numbers. The precipitates failed to appear on these juveniles in normal serum or in saline; nor did they appear on the third stage juveniles on incubation in immune sera. Apparently the excretory-secretory products of the fourth stage juveniles of O. columbianum serve as antigen and play an important role in the stimulation of antibodies in the host.

2. Inactivation of the immune serum did not destroy the precipitin type of antibody, nor was it affected when the immune animals had been treated with cortisone.

3. Immune serum from animals receiving multiple infections showed a higher antibody titre.

4. The possible way in which the antibody acts on the fourth stage juveniles, causing their immobilisation and subsequent death, is discussed.

A new Indian species of Paraphelenchus is described and compared with P. basili Das, 1960, also from India, and with other known species of the genus.

A post-parturient rise in worm egg count was seen in ewes which lambed in the autumn following ovulation induced by hormone treatment. Similarly treated ewes in the same flock which proved to be barren showed only a slight increase in egg count. There were indications that hormone treatment may be associated with egg count rises which differ in intensity and duration from those reported in ewes which ovulate spontaneously.

A successful peritoneal transplant of 5 Cardiofilaria nilesi adult worms, 3♀ Symbo; and 2♂ Symbo; is reported. Microfilaraemia in the recipient chicken was found on the 6th day after the transplant. The count rose to 4/20 c.mm., from 1/20 c.mm. in 19 days after the transplant. The highest count recorded was 14/20 c.mm. The microfilaraemia persisted for 63 days.

Three new species of the genus Opistholebes (Opistholebetidae Fukui, 1929) are described from the small intestine of the globefish, Tetraodon viridipunctatus (Gunther) in India.

A key to the species of the genus Opistholebes Nicoll, 1915 is given.

A detailed description and affinities of Durinema gracile, a nematode genus belonging to the family Belondiridae Thome, 1939 collected from Veraval (Gujarat) and Saharanpur (U.P.), India, are provided. It is characterized by its prominent lips, short, slightly dorsally arcuate spear, rod-like extensions, sheath of spiral muscles around the basal expanded portion of oesophagus, two ovaries and a conoid tail.

Aulolaimus oxycephalus de Man, 1880 is redescribed with observations on the lectotype male and on specimens from England. The definition of the family Axonolaimidae Sch. Stek. and de Coninck, 1933 is emended to include reflexed ovaries. Aulolaiminae n.subfam. is proposed, within the Axonolaimidae, for the genera Aulolaimus de Man, 1880 and Pseudoaulolaimus Imamura, 1931. A. meyli Loof, 1961 is considered to be a species inquirenda. Pandurinema Timm, 1957, is made a synonym of Aulolaimus and further observations are made on A. filiformis (Timm, 1957) n.comb.

A case of infection of an appendix with a whipworm, Trichuris trichiura is described. Only the thin pharyngeal part of the worm imbedded in the mucosa was observed in the sections, and whipworm eggs were not found in the patient's stools or appendiceal faeces.

In the autumn of 19G6 the writer received two samples of nematodes, containing over a hundred specimens, which were found in the pancreatic ducts of the mustelid Arctonyx collaris. The two host animals arrived from Bangkok, one already dead; the other died in the Zoological Garden of Emmen a week after arrival.

Aelurostrongylus abstrusus, the lungworm of the cat, has a world wide distribution and has been reported from countries as far apart as America, Great Britain and Palestine. It has a complex life cycle insofar as a molluscan intermediate host is essential and it is possible that auxiliary hosts also play an important part. In Britain, the incidence of active infestation of cats with the parasite has been recorded as 19·4% (Lewis, 1927) and 6·6% (Hamilton, 1966) but the latter author found that, generally, the clinical disease produced by the parasite was of a mild nature. It is known that the average patent period of the infestation in the cat is 8–13 weeks and it seems likely that, in that time, a considerable number of first stage larvae would be evacuated. Information on that point is not available and the object of the following experiment was to ascertain the number of larvae produced by cats during the course of a typical infestation.

The results of the fluorescent antibody test with sera from tropical eosinophilia and filariasis cases tested against four species of microfilariae are reported. The majority of sera from both groups showed the presence of antibody to the human parasite W. bancrofti. In the filarial group only those with clinically active disease of short duration showed a positive fluorescence reaction. Some sera of both groups reacted positively with microfilariae of the animal parasites B. ceylonensis and Setaria sp. These were species specific reactions as seen by diminished or absence of fluorescence after absorption of specific antibody.

A technique for the recovery and counting of infective strongyle larvae from macerated herbage obtained through oesophageal fistulae is described. The method is also useful for examining samples of herbage gathered by hand.

In May 1967 206 specimens (♂: ♀=1:1) of a nematode species were collected from the small intestine of a Pardofelis marmorata marmorata.

This paper reports on two species of digenetic trematodes, namely Gymnophallus deliciosus (Olsson, 1893) and Notocotylus chionis Baylis, 1928, from Sheathbills collected on Signy Island.(lat. 60° 43' S., long. 45° 36' W.), South Orkney Islands, in July and October 1965 by Mr Charles Howie of the British Antarctic Survey. The birds were preserved in deep-freeze and later passed to us for examination. An account of the cestode parasites of these birds has been given previously (Jones & Williams, 1967).