A Recent study by the writer (1924) on the type species of the genus Œsophagostomum, O. dentatum, from the pig, has brought to light certain interesting anatomical features and shown the desirability of a closer examination of the members of the genus occurring in other farm animals.

Three species of these are well known, namely, O. columbianum, O. radiatum and O. venulosum, and have been dealt with fairly completely within recent years by Ransom (1911) and Railliet and Henry (1913), but even in the accounts of the worms given by these authors, there are certain differences concerning details of structure, which suggest the need for further investigation. Again, in studying O. dentatum, it was found that the genital cone of the male had a well defined structure, and it seemed of interest to determine whether the genital cones in the other species were built on the same general plan as that of O. dentatum, and whether they possessed specific differences from it and amongst themselvse

Since the beginning of October, 1923, the writer had the opportunity of collecting helminths from 25 horses slaughtered in Edinburgh, and from 20 horses and one donkey slaughtered in London.

The Edinburgh material was collected during the months October, November and December from aged horses, the London material during February, March and April, likewise from aged horses and from a very old donkey. The donkey was found to harbour at least 26 species of nematodes, 15 of which have not hitherto been recorded from England.

From the horses examined in London, 38 species of helminths were obtained, 19 of which are new to England, and in Edinburgh 38 species, 11 of which have not hitherto been recorded from Scotland.

In the collection of nematodes assembled by Prof. R. T. Leiper in this department there are numerous examples of worms from game animals in different parts of the world. Amongst these the writer, in further study of the Œsophagostomes, has been privileged to examine bottles of some provisionally labelled Œsophagostomum, sp.? One lot was collected from the Roan antelope (Hippotragus equinus) by Dr. J. E. S. Old in Nyasaland, another was collected from the Wart Hog (Phacocærus æthiopicus) in Uganda by Prof. R. T. Leiper. The other bottle contained worms from the latter host collected in Northern Territory Gold Coast, by Dr. J. J. Simpson on two different occasions. A study of these specimens shows that they comprise three species new to science, and one species just recently described by Daubney (1924).

In 1839 Diesing described Stephanurus dentatus from the kidney of the pig. His description was incorrect in two important particulars, viz.— in stating that only one spicule was present and that the vulva was in the middle of the body instead of posteriorly. These errors, although corrected by Verril in 1870 and Louise Taylor in 1899, still persist, and it was on account of this that Drabble, in 1922, basing his diagnosis on a faulty text-book description, claimed that the Kidney worm of swine in New South Wales was generally distinct from Stephanurus dentatus. This worm he called Sclerostomum renium, n. sp.