The members of the nematode genus Rhabdias present many features of great interest to the parasitologist. They are usually found inhabiting the lungs of amphibians and reptiles where their eggs or larvæ are produced. They have the general appearance of females and are either hermaphroditic or parthenogenetic in function (vide Goldschmidt, 1923, p. 176, on “Unisexual Monœcism”). Seurat (1920), p. 121, considers that the parasitic forms of R. dujardini and R. entomelas from the Slow worm Anguis fragilis are parthenogenetic females and not protandrous hermaphrodites because they lay an enormous number of eggs, whereas the hermaphroditic forms produce comparatively few eggs. Moreover, in R. entomelas he has been unable to find either receptacula seminis or spermatozoa.

The material on which this paper is based was received by Prof. R. T. Leiper from several sources, and includes specimens collected in British Guiana by the Filariasis Commission, in West Africa by Dr. Yale Massey, and in New Guinea by Dr. G. M. Heydon. In addition there was a tube received from Dr. O'Connor from Samoa labelled on the outside of the bottle “Pig, Samoa, Ank. Duod. from intestine,” and inside (presumably by Dr. Clayton Lane) “Crassisoma samoense.” It contained specimens of the latter species only. The type material of Lane's two new species from the pig was also available for examination.

Being engaged on a complete revision of the genus Inermicapsifer Janicki (1910), we had occasion to examine some material from the Helminthological Department of the London School of Tropical Medicine. This material was kindly placed at our disposal by Prof. R. T. Leiper, F.R.S., to whom we here tender our sincerest thanks. We are also indebted to Prof. O. Fuhrmann for his useful advice and criticisms.

This parasite was discovered in April, 1876, at Zagazig, Egypt, by Sonsino. He collected 35 specimens from the abdominal veins of oxen and sheep and from the portal vein of a bull. He stated that the parasite is larger than S. hæmatobium and has the same general aspect and characters, but is easily distinguished by the shape of the eggs. The eggs of S. bovis are .16 mm.-.18 mm. long and .04-.05 mm. broad, fusiform in shape and very much narrowed at the extremities. The pole which, in the oviduct, is turned away from the vulva, always carries a pyriform spine.

During a recent visit to Copenhagen, through the courtesy of Dr. Bahr and of the Chief Veterinary Superintendent, I visited the Central Meat Market. Veterinary inspection of all living animals sent to the market is exercised, as well as of all carcases. If a carcase appears the least abnormal, without definite macroscopic changes, it is examined bacteriologically in an attached laboratory, equipped and staffed for the purpose, and all carcases of pigs, as well as any imported swine products, e.g., American hams, are subjected to examination for trichinosis. For this purpose, three small pieces of tissue are taken from every carcase or ham. From each piece of tissue six specimens are prepared for microscopical examination, so that eighteen microscopical specimens in all of every carcase, or other swine product, are subjected to examination. For the examination a “compressorium” is made use of, consisting of two rectangular pieces of plate glass, measuring about 6 in. × 2½ in., which are clamped together by a threaded bolt with nut at either end. One plate is divided into eighteen numbered squares, six squares longitudinally by three squares transversely. Particles of tissue about the size of a rice grain or so, with a drop of saline solution, are each placed in a square, so that the precise derivation of the material in each square may be recorded by its number. When all the squares have been filled, the corresponding plate is applied and screwed up, so as to squeeze out the tissue into a layer thin enough for microscopical examination with a low power, and in area about the size of a shilling. So far, there is nothing novel in the method, which has been practised for years, e.g., at Hamburg. But at Copenhagen, instead of direct microscopical examination of the specimen, an image of it is projected on to a screen, and is viewed thereon with the naked eye. One assistant can examine 100 specimens a day.

The area covered by this Survey does not admit of exact delimitation, but it might roughly be stated as that region of North Cardiganshire extending for a radius of about fifteen miles from Aberystwyth. Cardigan Bay and the Dovey Estuary form natural boundaries on the West and North respectively, while the Plynlimon range of mountains runs along the eastern side and forms an elevated plateau about 1,500 ft. above sea level. The area is therefore somewhat self-contained, comprising the more or less gradual slope from this plateau westwards to the sea.

While examining some sections of a specimen of Inermicapsifer hyracis (Rud.), we came across an extremely interesting and, what we believe to be, a unique occurrence.