Immersion of Biomphalaria pfeifferi in 1.5% glucose solution showed that the snails did not absorb any glucose during the first six hours but that almost 30% of the glucose was absorbed after 24 hours. The glycogen content of such “glucose-fed” snails was much higher than that of control normal snails. Cercariae of S. mansoni collected from the former snails exhibited a much lower level of death (20%), during penetration of mouse skin, than that of control normal cercariae (36%).

It is suggested that death of S. mansoni cercariae during penetration of mammalian host skin is probably due to exhaustion of their energy reserves.

The genus Paraheterotyphlum is upheld, the type species, australe Johnston and Mawson, 1948, is redescribed from the type material and compared with specimens collected from the following sea snakes from Australian waters: Pelamis platurus, Hydrophis elegans, Aipysurus laevis, Astrotia stokesii, Disteira kingii. These specimens were also compared with specimens from Laticauda semifasciata and colubrina from Taiwan waters.

Two species are differentiated: P. australe and P. ophiophagos Schmidt and Kuntz, 1973 mainly by the larger and more distinct interlocking facets on the lips of the latter species. Third and fourth stage larvae, probably of P. australe are described and the distribution and affinities of these species is discussed.

Microfilariae of Onchocerca sweetae are broadly distributed in the superficial layers of the dermis of the water buffalo (Bubalus bubalis). A total of 2855 insects representing 20 species were collected from O. sweetae-infected bait buffaloes. Only one species, Culicoides sp. “M”, ingested microfilariae from buffalo skin. Larval development of O. sweetae was observed in the thorax of this species. A total of 829 insects, representing 7 species and including 749 parous Culicoides spp. were collected from light and Manitoba traps. Developing filarioid larvae were observed only in Culicoides sp. “M”. It is concluded that Culicoides sp. “M” is a natural intermediate host of O. sweetae in the Northern Territory of Australia.

Morphological variations in Onchocerca armillata and O. gutturosa, from buffalo and cattle, with special reference to male tail and cuticular ornamentation, have been studied from a large collection of worms available from the infected aortae and ligamentum nuchae, procured from slaughter houses at 3 different localities in Uttar Pradesh, India. Seven variations in the disposition of caudal papillae in males in O. armillata and 14 in O. gutturosa are described. The prevalence of these two Onchocerca species in bubaline and bovine populations appears to be widespread.

Only five of the eight species assigned to the genus Paracooperia are considered valid and are redescribed. P. petrowi Memmedov, 1961 and P. indiana Ali and Deshpande, 1970 are considered synonyms of P. nodulosa (Schwartz, 1928) Travassos, 1937 and the synonymy of P. matoffi Le Roux, 1950 with P. nodulosa is confirmed. A key to the species of the genus is given and their hosts and geographical localities are listed.

The ascaridoid nematodes with more than two uterine branches, which occur in snakes and lizards, are grouped into three genera: (1) Polydelphis (without interlabia, with four uterine branches) containing the type species, P. anoura, occuring in Old World Pythons, with P. brachycheilos as a species dubium. (2) Travassosascaris, a new genus with interlabia and with four uterine branches, with type species T. araujoi (new name for P. quadrangularis (Schneider) of Araujo, 1969) occuring in New World rattlesnakes. (3) Hexametra, (without interlabia, with six uterine branches) containing species in lizards and snakes. In lizards, H. hexametra (type species), H. applanata, H.angusticaecoides and H. rotundicaudata are tentatively differentiated. In snakes, two Hexametra species are tentatively differentiated: (1) H. boddaertii (with three synonyms) in New World pit vipers and colubrids; (2) H. quadricornis (with twenty-two synonyms) in Old World viperids, elapids and colubrids. The morphology, host range, geographical distribution, development and harmful effects of these species are discussed.

The activity of maltase, saccharase, cellobiase, trehalase and lactase was estimated in the intestinal contents of non-infected pigs and pigs infected with several gastrointestinal nematodes and in the nematodes themselves.

Enzyme activities in the intestinal contents of pigs infected with Hyostrongylus rubidus were similar to those in uninfected control pigs. However the enzyme activity of the contents of the whole intestine was increased in Strongyloides ransomi infections and moderately increased in Ascaris suum infection. In Trichuris and Oesophagostomum infections activity was only increased in the large intestine contents.

Ascaris suum contained high activity of maltase and saccharase in its intestine and lower levels in other organs, while levels were much lower in other pig nematodes. Hyostrongylus rubidus and its third-stage larva did not contain any disaccharidases activity.

The disaccharidases in the pig nematodes, especially in Strongyloides, were more sensitive to high temperatures (70°C) than those in the contents of the pig intestine.

Some disaccharidases were demonstrable in embryonated Ascaris and Trichuris eggs and in third-stage larvae of Strongyloides and Oesophagostomum.

The life cycle of Genarchopsis goppo a hemiurid trematode found in the stomach of Channa punctata has been worked out in detail. The egg contains a fully developed miracidium at the time of liberation. The miracidium contains a ciliated covering, a long apical gland and a crown of spines at the anterior end. The snail Amnicola travancorica acts as the first intermediate host inside which the miracidium passes through sporocyst and redial generations. The cercaria is of cystophorous type and is identical to Cercariae Indicae Sewell XXXV. Metacercaria occurs in the ostracods Stenocypris malcolmsoni and Eucyoris capensis. The fish Aplocheilus panchax serves as the paratenic host. The entire developmental cycle from egg to egg producing adult takes 3 months.

A new species in the genus Goezia is described from aquatic reptiles of the northern shores of Australia, west of Cape York Peninsula. It was collected from Crocodylus porosus, from a file snake (Achrochordus granulatus), and from sea snakes (Lapemis hardwickii, Enhydrina schistosa, Hydrophis elegans, and H. caerulescens). The new species is compared with G. fluviatilis from Australian freshwater fish, with G. minuta from marine fish of the east coast of North America, and with G. spinulosa and G. intermedia from South American freshwater fish. The host-relationships of the genus are discussed.

Two new genera, Gedoelstascarisand Ortleppascaris, are proposed for species of ascaridoid nematodes occurring in crocodilians and previously included in Dujardinascaris. Species included in Gedoelstascaris are vandenbrandeni Baylis, 1929 as type species and australiensis Baylis, 1931 (= salomonis Kreis, 1940). These species occur in Crocodylus spp. in Africa and Australia respectively and are characterised by lips with a rostral plate, without interlocking processes or dentigerous ridges, with well-developed interlabia, lobulated ventriculus, and excretory pore in front of the nerve ring. Species included in Ortleppascaris are: nigra Gedoelst, 1916 (= tasmani Ortlepp, 1932) as type species; alata Baylis, 1947; antipini Mozgovoy, 1950. These species occur in Crocodylus, Caiman and Alligator and are characterized by flat lips with alate margins, without anterior rostral plate, interlocking processes or dentigerous ridges, with weakly developed interlabia, by an irregular-shaped ventriculus, excretory pore behind or between the subventral lips, and by the presence of lateral alae or cuticular thickenings in the oesophageal region. The significance of this proposal is discussed in relation to the radiation and dispersal of ascaridoids of crocodilians.