Adult specimens or parts of specimens of Wuchereria were recovered from the lymphatic systems of a Kra monkey (Macaca irus) (1), domestic cats (4), a dog (1) and a Slow Loris (N. coucang), from areas of endemic human filariasis in Pahang, Malaya.

Morphological studies on this material revealed a new species, herein named W. pahangi, in the dog and in one cat; a species in the Kra monkey which is close to and probably identical with adults of W. malayi as described by Bonne el at. (1941) from man in Indonesia; but its relationships, and also those of the species from man in Indonesia, with the W. malayi described by Rao & Maplestone (1939) in India need further investigation. Three cats harboured a species which is close to that in the Kra monkey but its identity is sub judice until further material is available. Fragments only of a female worm, which included the tail, were recovered from the Slow Loris. It is thought that this material may be the new species W. pahangi.

The nematode Trichostrongylus longispicularis was described by Gordon (1933) from a single male recovered from a sheep in New South Wales. Gordon considered that the male of this species could be readily distinguished from the males of other species of the genus recorded from ruminants by an asymmetrical dorsal ray of the bursa and by the length and form of the spicules. The dorsal ray is described as being bifid, one bifurcation being simple and the other possessing secondary branches, one situated internally and the other externally. The slender spicules were 184·6 microns long, and terminated in fine sickle-shaped structures.

Andrews (1934 and 1935) recorded the species from cattle in the United States. In his first description (Andrews, 1934) he noted that his specimens agreed very closely with the description published by Gordon (1933), but he referred to hook-like projections on the spicules. However, he failed to find these projections in the specimen discussed in his record of 1935. As he made no reference to the dorsal ray of the bursa, it is presumed that this agreed with the description and figure published by Gordon (1933). T. longispicularis was subsequently reported by Roberts (1938 and 1939) from cattle in Queensland, but no comments were made on its morphology.

The development of the microfilariae of Litomosoides carinii from the ova, has been studied by phase-contrast microscopy, and recorded with photomicrographs. All stages in the development were obtained by puncturing the uteri of adult female worms at intervals along their lengths, transferring the larvae which emerged onto agar coated slides and allowing the weight of a coverglass to flatten them sufficiently for detailed examination.

The head and the tail end of the larva were differentiated at a fairly early stage and about the same time a hook-like structure appeared on the head. Subsequently a body cavity was formed within the larva which was associated with the appearance of highly refractile subcuticular cells. Later this cavity became filled with different types of cells.

Throughout its development the larva was enclosed within a membrane which was later stretched by the movement of the larva to form the sheath of the microfilaria. All the microfilariae from the adult female worms, from the pleural fluid, and from the peripheral blood of the large number of infected cotton rats examined, were seen by phase-contrast microscopy to have sheaths.

C. pygocytophora emerges from P. carinatus predominantly in the dark, independently of the time of day, and in the absence of temperature variation.

C. Pygocytophora shows strong negative phototaxis.

An account is given of the general morphology of Echinopardalis lerouxi n.sp., from the intestine of Canis adustus, in Northern Rhodesia. This new acanthocephalan agrees with the characters of the genus Echinopardalis, and differs from all the other known species included in this genus. The characteristic features of the species are enumerated.

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.

Four new species of Strigeid Trematodes are described from Central African Birds of Prey. They are: Strigea neotidis from Neotis cafra denhami, Strigea lilensis and Strigea rhodesiensis from Pseudogyps africanus and Strigea cuncumae from Cuncuma vocifer vocifer. The relationships of these new forms to other species in the genus Strigea are discussed.