A new genus, Alainchabaudia, is proposed, apparently close to Hartertia, but differing in the presence of modifications of the anterior end of the buccal capsule, which is prolonged dorsally and ventrally and ends in four submedian teeth. Two species are included: the type species, C. alcedinis sp.nov., from Halcyon sanctus (Queensland and South Australia) and Dacelo gigas (New South Wales); and A. aegotheles (Johnston & Mawson) syn. Habronema aegotheles J. & M., from Aegotheles cristata (South Australia).

The specimens from Queensland were lent by Dr John Pearson of the School of Parasitology of the University of Queensland. The bodies of the other two birds were sent to me for dissection, Dacelo gigas by Mr H. J. de S. Disney, Curator of Birds in the Australian Museum, Sydney, and Halcyon sanctus by Mr H. Condon, Curator of Birds in the South Australian Museum, Adelaide. I am most grateful to these gentlemen for their assistance.

A list is given of all habroneme species recorded from Australian birds, as well as a key to all known genera of Habronematinae. New species described are: Cyrnea (Procyrnea) dollfusi from Ninox novaeseelandiae; Cyrnea (Procyrnea) falco from Falco longipennis and F. berigora; Cyrnea (Procyrnea) spiralis from Philemon argenticeps, Entomyzon cyanotis, Oriolus sagittatus and Lalage sueuriitricolor; Excisa biloba from Podargus strigoides, Ninox novaeseelandia; Viguiera longicollis from Colluricinda rufiventris, C. harmonica, Anthochaera carunculata and Microeca fascinans; V. chibiae from Chibia bracteata; V. chabaudi from Podargus strigoides. Partial redescriptions are given of Cyrnea (Procyrnea) paraleptoptera (Johnson & Mawson) from the type specimens; Cyrnea (Procyrnea) mansioni from Falco berigora, Haliastur sphenurus, Astur novaehollandiae, and a ‘hawk’; Cyrnea (Procyrnea) sp. from a parrot, Psephotus haematonotus; Hadjelia truncata from Eurystomus orientalis; Hadjelia acuariana (s. Stellabronema acuariana Gushans-kaya) from Podargus strigoides; Torquatella balanocephala from Merops ornatus, and Torquatella sp. from Centropus phasianus.

Paucivitellosus fragilis i sredescribed from the blenny, Salarias meleagris, found on beach-rock intertidally at Heron Island, Great Barrier Reef. The adult was also found in the mullet, Mugil cephalus and Crenimugil crenilabis at Heron Island, and Liza argentea at Brisbane.

Paucivitellosus differs from Bivesicula, Bivesiculoides and Treptodemus in having: (i) the vitellaria reduced to a single follicle on each side, (ii) two primary loops in the uterus, (iii) fully embryonated eggs in the terminal coils of the uterus, and (iv) the cirrus pouch orientated dorso-ventrally. The diagnosis of the family Bivesiculidae is emended.

The molluscan host at Heron Island is Cerithium penthusarus, in which cercariae develop in ‘fork-tailed’ rediae.

The cercaria is furcocystocercous and differs from known bivesiculid cercariae in having a protrusible glandular fold, within the mouth of the invaginated caudal chamber, by which the cercaria attaches to objects.

Evidence is presented for the view that the life-cycle is a two-host one, that there is no metacercarial stage, and that the cercaria is ingested by browsing.

I should like to thank the Great Barrier Reef Committee for the use of facilities at the Heron Island Research Station, where the field work was carried out. Professor H. W. Manter, University of Nebraska, generously donated all of the bivesiculid material that he collected in Australia, including adults of Paucivitellosus fragilis from the warty-lipped and sea mullet. Mr N. Milward and Mr H. Choat, of the Department of Zoology, kindly identified the fish hosts and furnished information on their feeding habits, and Dr D. F. McMichael, of the Australian Museum, kindly identified the snail host. Dr W. H. Coil, University of Kansas, kindly lent three paratypes (?) of P. fragilis. Thanks are also due to Mr R. J. Ballantyne for his able technical assistance in the collection and preparation of material.

The work was supported by a research grant from the University of Queensland.

A survey of lungworm infection in rats in Queensland has shown that 23% of Rattus norvegicus, 6·5% of R. rattus 4·5% of R. fuscipes and 0% of Melomys cervinipes were infected with lungworms. Detailed examination of the lungworms revealed that there are two distinct species; one is Angiostrongylus cantonensis which was found to occur in R. norvegicus and R. rattus, the other is a new species, namely, A. mackerrasae, which was found in R. fuscipes in an area of rainforest near Brisbane. Some R. norvegicus in Brisbane also harboured A. mackerrasae. The two species were distinguished by the length of the spicules, relative length and appearance of the postero-lateral ray in the male, the presence of a minute projection at the tip of the tail in the female, length of the vagina and the distance between anus and vulva. The first-stage larvae of the two species were found to be identical. As this species has been found to be the only lungworm in R. fuscipes which is an indigenous Australian rat, it is suggested that A. mackerrasae may have originated in the Australian region.

I wish to express my sincere gratitude to Professor J. F. A. Sprent and Dr L. R. Ash for their advice and encouragement during this study. Special thanks are also due to Miss M. Cremin for her assistance and to Mr H. Lavery for providing specimens from North Queensland. This work was supported by a grant from the U.S. Department of Health, Education and Welfare No. A 107023–02.

Glossina pallidipes Austen have been successfully reared in the adult stage in the laboratory. The flies fed readily on the belly of guinea-pigs, and the latter did not seem to be worried by the attentions of the flies.

Immediately after adult emergence the flies were kept individually in tubes at four different temperatures (20°, 22°, 24° and 28 °C), at a relative humidity of 40 ± 5%, and they were offered guinea-pigs daily. Fifty per cent of the flies reared at temperatures of 20° and 28 °C died during the first 5 days, 50% of those reared at 24 °C died during the first 10 days, and 50% of those reared at 22 °C lived for more than 50 days.

Few flies reared at 20° or 28 °C fed at all, and those that did had only four or five meals in their life-time; most of the flies reared at 22° or 24 °C did feed, but those reared at 24° took only a few meals. Most of these meals were ‘full’ ones, but a considerable proportion of meals taken by flies reared at 20 °C were ‘partial’ ones. The interval between meals was usually 3 or 4 days; but the time taken between adult emergence and time of first meal was shorter, except for the flies reared at 20 °C.

When tsetse flies are reared at 22 °C the first six blood-meals are smaller than subsequent ones. The size of the meals and the rate of body growth do not seem to be related to the gonadotrophic cycles. On the other hand, the terminal phase of growth in both sexes shows a steady increase in body weight.

The factors that might influence feeding, growth, and the longevity of adult tsetse flies are discussed.

Thanks are extended to Mr J. M. B. Harley of the East African Trypanosomiasis Research Organization for sending me tsetse pupae, to Miss Caroline Walter and Mr John Boro for technical assistance, and to the Rockefeller Foundation for a research grant.

It was found that antelopes in the Serengeti area, Tanzania, East Africa, are heavily infested with lung nematodes. Five species of the family Protostrongylidae, namely, Protostrongylus africanus sp.nov., P. etoshai Ortlepp, P. gazellae Yeh, Pneumostrongylus calcaratus Mönnig and P. cornigerus Ortlepp, as well as one species of the family Dictyocaulidae, Dictycaulus viviparus (Bloch), were recorded.

A detailed description of Protostrongylus africanus sp.nov., which is conspicuous for its gigantic size, is given, and the lesions caused by this lung nematode are described.

The distribution and incidence of lung nematodes in the various antelope species are discussed.

Chevreuxia americana sp.nov. is described from the gizzard of the avocet, Recurvirostra americana, in Colorado. It is compared with the four previously described species in the genus.

Mitotic metaphase chromosomes of the tsetse fly Glossina palpalis R.-D. have been investigated.

The chromosomes studied were in circumoesophageal nervous tissue from young pupae, stained with aceto-orcein and spread by squashing.

The diploid number of chromosomes was shown to be 6, consisting of 2 long pairs and 1 short pair at metaphase.

This finding is discussed briefly in relation to previous descriptions of the chromosomes of G. tachinoides West. and G. morsitans morsitans West. and to accepted systematic divisions of the genus Glossina into subgeneric groups.

I wish to thank Mr H. Dickson for assistance with photography. I thank Mr D. A. T. Baldry for advice and suggestions concerning the manuscript. Mr T. M. Leach has also made suggestions concerning the manuscript, and as Director of the Nigerian Institute for Trypanosomiasis Research, has given his permission to publish this paper.

Myxidium oviforme is described from Irish salmon Salmo salar. Its close relationship with M. folium, M. moxostomatis and M. aplodinoti, and its possible economic importance are discussed.

Attempts to establish infections of M. oviforme in young, parasite-free salmon are described, and the reasons for their negative results discussed.

This work was carried out during the tenure of a Medical Research Council Scholarship for Training in Research Methods between October 1964 and September 1966, and forms part of a thesis submitted for the Ph.D. Degree of the University of London. Grateful acknowledgement is due to Dr J. G. Ross and Dr G. Lawson of the Veterinary Research Division of the Ministry of Agriculture for Northern Ireland for information on salmon infections in Ireland, to the Ministry of Agriculture and Fisheries for the provision of young salmon, and to Messrs Barnetts of Frying Pan Alley Ltd., London, for the provision of salmon livers.

Syphacia (Syphatineria) oceanica sp.nov. is described from the squirrel Sundasciurus steerii juvencus. It is closest to S. transafricana Chabaud & Biocca, 1955, differing from it in having a cephalic vesicle, an isthmus between oesophagus and bulb, and in characteristics of the gubernaculum. Syphacia (Syphacia) critesi sp.nov. is described from S. steerii juvencus and the flying squirrel Hylopetes nigripes. It is closest to S. thompsoni Price, 1928, differing from it in lacking cephalic vesicle, alae, and cervical papillae; in having a long oesophagus and shorter gubernaculum Syphacia (Syphacia) magnispicula sp.nov. is described from H. nigripes and S. steerii juvencus. It is characterized by having a spicule 312–338 μm long, much longer than any species yet reported. Syphacia (Syphacia) coli sp.nov. is described from H. nigripes and the rat Rattus exulans luteiventris. It is closest to S. critesi sp.nov., differing from it in sizes and shapes of oesophagus and gubernaculum, in having lateral alae, and in egg size. Syphacia sp. is reported from Rattus exulans luteiventris; Blattophila sp. is reported from the skunk Mydaus marchei; and Allodapa sp. is reported from Sundasciurus steerii juvencus.

The authors wish to express their appreciation to Dr D. S. Rabor, Silliman University, Dumageute, Negros Oriental, Republic of Philippines, for general support in field activities and for tentative host identifications; Mr Max Thompson, Bishop Museum, Honolulu, for assistance in collection of hosts and Dr David H. Johnson, Research Curator, Division of Mammals, U.S. National Museum Washington, D.C., for final host identifications. Thanks are extended to Dr W. G. Dyer and Dr P. D. Leiby, Minot State College, for technical assistance during the course of this work, and to Dr W. W. Becklund, Beltsville Parasitological Laboratory, for the loan of specimens for comparative purposes. Special thanks are due to Mrs MayBelle Chitwood, whose efforts greatly improved the quality of this work.

Macrolecithus papilliger sp.nov. from the stomach and intestine of Phoxinus phoxinus (L.) is described and its systematic position discussed. The life span in the fish, in captivity during January, is 5–6 weeks. The sequence of events in release of oocytes from the ovary and egg capsule formation has been observed in living specimens. Mature oocytes, in the ovary, are enclosed in groups of eight in a transparent membrane which ruptures, releasing them singly into the ovicapt. The egg capsule is formed in two stages: a transparent membrane is secreted, probably by Mehlis's gland, around the oocyte and vitelline cells in the ootype; later this is reinforced by vitelline globules released from the vitelline cells. These coalesce on the inner side of the membrane. The operculum is formed in the ootype. Histochemical tests support the observations.

I would like to express my gratitude to Mr S. Prudhoe, British Museum (Nat. Hist.), for helpful comments on this species and to Mr M. C. Bibby and Mrs M. Fisher for technical assistance.

The work was supported by a grant from the Science Research Council, for which I am most grateful.

Saline extracts of species of Ditylenchus and Heterodera initiated antibody production when inoculated separately into rabbits. On agar gel-diffusion plates these antisera gave a precipitate response against their homologous extracts and against extracts of some of the other nematode species. Up to four precipitation bands occurred, indicating the presence of at least four distinct antigens. Antisera to these extracts did not precipitate against extracts of the host plant or against the extracts of nematodes from other genera. None of the nematode extracts precipitated against normal serum. The precipitation response divided the Heterodera species tested into two groups, one containing H. schachtii, H. trifolii and H. rostochiensis and the other containing H. cruciferae, H. carotae and H. goettingiana with apparently no antigens common to both groups. The three species of Ditylenchus were serologically distinct, and it was not possible to interbreed D. myceliophagus and D. destructor. The extent of the postvulval sac was the most useful morphological character for separating D. myceliophagus from D. destructor. Only slight intraspecific serological differences were detected between five races (narcissus, oat, red clover, tulip and giant) of D. dipsaci and between the two pathotype populations (Colyton and Woburn) of H. rostochiensis. Precipitates occurred at the excretory pore of living larvae and adults of Ditylenchus species and at the vulval aperture of white females of Heterodera species placed in their homologous antisera.

We thank Dr A. J. Gibbs for much advice.

The life-history of I. pacificus when fed on guinea-pigs under laboratory conditions is described. Feeding of the female proceeds for 10–11 days. Between 120 and 191 mg of concentrated food is found in the female's gut on detaching from this host, and this is directly related to the unfed body weight of the tick.

The egg-laying pattern, in general, shows an initial peak, after which the number of eggs tails off, the whole process lasting approximately 33–40 days. The number of eggs laid by females varies between 790 and 1300. The preoviposition period is about 11–16 days.

Larvae hatch in about 53–55 days, and their feeding time ranges from 4 to 9 days, although in the present experiments larvae emerging from early laid eggs took about 10 days to complete engorgements.

Moulting of larvae to nymphs at 90% R.H. took 37–38 days, and nymphs fed for 7–11 days, with most becoming replete on the ninth.

Very few females emerged from these nymphs, and those that did emerged in just over 30 days. The reasons for this are not clear. No diapause appeared to be necessary to complete the life-cycle, and with due allowance for hardening of the mouthparts the life-history of one generation was about 7 months. Females died within 3 or 4 months if hosts were not available.

From the literature and from hitherto unpublished records some 55 vertebrates have been implicated as hosts to I. pacificus; these hosts include a wide range of mammals, six species of birds and possibly nine species of lizards.

The species has been listed from British Columbia and from five western states of U.S.A. The need for more intensive ecological work on this species is emphasized.

We are indebted to Glen M. Kohls, J. D. Gregson and D. E. Johnstone for permission to use unpublished records from their respective institutions. One of us (D.R.A) is also indebted to the Wellcome Trustees for financial assistance to visit Canada during the preliminary stages of the work.

The growth and morphology of the excretory system of Stephanurus dentatus were investigated using both the light microscope and the electron microscope. In the 3rd-stage larva a branched tubular system extends from the posterior end of the excretory ampulla. The subventral glands are two elongated cells in the body cavity, and these do not appear to be attached to the tubular system.

The tubular and glandular portions of the excretory system are intimately associated with each other at the posterior end of the ampulla or sinus from the 4th-stage, but throughout their development they remain histologically distinctive. Moreover, the nuclei of each portion of the system are of two different types; those of the tubular system are similar to hypodermal nuclei, whereas the nuclei of the subventral glands are like the intestinal nuclei.

The lateral canals are extensions of the excretory sinus and lie embedded in the hypodermal tissue of the lateral chords. As the worm matures, the lateral canals increase in relative length, and the anterior branch of each lateral canal develops during the 4th stage.

Pink viscous fluid which passes from the excretory pore is identical in appearance with the fluid which is found in the lateral chords. It is suggested that the fluid in the lateral canals gains access to the excretory system by way of canaliculi in the wall of the lateral excretory canal.

I am most grateful to Professor J. F. A. Sprent for his interest and advice during this investigation, and to Mr J. J. Mines and Mr C. Boel for their able technical assistance. I gratefully acknowledge the financial support given for this study by the Australian Dairy Produce Board and the U.S. Department of Health, Education and Welfare (No. A 107023–02).

The oncomiracidium of Merizocotyle sp., a monocotylid monogenean from the nasal fossae of Raia undulata, has 14 marginal hooklets. It seems probable that these larvae swim directly into the nasal fossae or are carried through the nostrils by the olfactory water current without first attaching themselves to the body skin. The marginal hooklets are then supplemented by a pair of hamuli and by 23 suckers, arranged in two concentric rings. The suckers arise as pockets in the ventral surface of the haptor and develop successively in a postero-anterior direction, the inner ring reaching completion before the outer ring.

I would like to express my thanks to the Director, Professor R. Weill, and to the Staff of the Station Biologique at Arcachon in France. I am grateful to the Royal Society for a Pergamon Travel Award, which enabled me to visit Arcachon.

I would also like to thank Mrs Mary Hutchinson for assistance with histological work.

Phyllobothrium piriei sp.nov. (Cestoda: Tetraphyllidea) from the intestine of Raja naevus in the North Sea resembles P. dagnallium, P. radioductum and P. britannicum more closely than any other known species of the genus but differs from these mainly in its host, in having distinctly bifid bothridia with faint marginal loculi and about 150 testes in each proglottid. Brief comments are made on the preference shown by the adult for the posterior region of the intestine and on a modification of its bothridium for attachment to up to 12 villi.

This work was supported by generous financial aid from the Natural Environment Research Council. I wish also to record my gratitude to Professor V. C. Wynne-Edwards and Dr P. A. Orkin for reading and suggesting improvements to the manuscript and to the Director and staff Marine Laboratory, Aberdeen, in particular Dr B. B. Rae and Mr Stuart Pirie, after whom this species has been named, for providing live rays. Alasdair McVivar of this department, who has now begun an independent study of the intestine of Raja naevus as a habitat for helminth parasites, kindly provided information for Fig. 9.

Rats can be passively protected against N. brasiliensis either with antiserum or with cells. Only some pools of antiserum (15 of 48 pools) and a few batches of cells (three of 11 batches) were protective.

Protective activity was found in serum taken after one infection as frequently as after several infections and gave the same degree of protection. This suggests that second and subsequent infections do not stimulate an anamnestic increase in protective antibodies in the circulation.

Serum and cells taken from the same rats were unrelated in their protective capacity; sometimes serum protected when the cells were ineffective and the reverse also occurred.

Cells transferred from the spleen, peritoneal cavity or mesenteric lymph nodes were capable of initiating reagin formation, irrespective of their ability to protect against N. brasiliensis.

When protection was achieved with transferred cells, the parasite life-cycle was shortened by only 1–2 days.

We have found no evidence that a delayed mechanism of the homograft type is concerned in immunity to N. brasiliensis in the rat.

We thank Miss W. D. Griffiths and Mr A. J. Edwards for their willing assistance. The statistical analysis was kindly done for us by Miss M. V. Mussett of the Statistics Department at our Institute.

Studies have been undertaken to examine the alternative hypotheses of a Poisson or a negative binomial distribution of the numbers of strongyloid nematode eggs in deposits of faeces produced by flocks of grazing sheep, which were proposed in certain mathematical models for the distribution of strongyloid infective larvae on pastures.

Observations were made on the distribution of the weights of faecal deposits produced by flocks of ewes and lambs. In all cases the distribution was found to be significantly positively skewed. A possible fundamental basis for this skewness has been suggested.

The distribution of strongyloid egg concentration in random samples of faecal deposits collected from pasture, and the distribution of egg concentration for the single species N. battus and N. filicollis in rectal samples of faeces collected from a lamb flock, have both shown highly significant departures from a Poisson distribution. This, coupled with the fact that the weights of individual deposits vary widely, provide strong empirical grounds for rejecting the Poisson distribution as a model for the distribution of egg numbers per deposit.

An examination of the distribution of egg counts for N. battus and N. filicollis in samples of faeces collected from a lamb flock at weekly intervals through the spring and summer has suggested that the distribution tends to become more overdispersed with the passage of time and as the mean egg count is falling.

Fundamental grounds for preferring a more general model, such as the negative binomial, to describe the distribution of strongyloid egg output in flocks of sheep have been discussed.

These studies were carried out under the supervision of Dr H. D. Crofton, to whom I am deeply grateful for his stimulating encouragement and constructive criticism. My thanks go also to Professor J. E. Harris, C.B.E., F.R.S., for the provision of facilities in the Department of Zoology, and to Professor T. K. Ewer and Mr M. R. McCrea for the provision and handling of pastures and sheep at the School of Veterinary Science, Langford. This work was undertaken during tenure of a C.S.I.R.O. Overseas Research Studentship.