In 1925 I described a new species of Monopylidium, M. chandleri, proposed a new subgenus Macracanthus for this and two related species, and proposed a new genus Southwellia for the species Monopylidium gallinarum Southwell 1921. Dr M. C. Hall has very kindly drawn my attention to certain errors and omissions in this paper which are herein corrected.

Family Diagnosis. Copepoda parasitic dorsally on Polynoid Worms.

Female with body divided into cephalothorax (head and neck) and trunk. No appendages articulated or otherwise on head or neck. No traces of segmentation. No mouth nor alimentary canal. Cuticle thin. Head and neck buried in the tissues of the host; the head converted into a voluminous organ whose only function is to absorb nutritive materials by endosmosis through expansions or rootlets. Head and neck at right angles to the middle of the trunk. A chitinous ring is usually present at the base of the neck at its insertion on the trunk. Genital apertures wide, the pyriform eggstrings issuing therefrom.

Dans un travail publié précédemment dans cette revue, nous avons montré que la concentration moléculaire du liquids cœlomique d'Ascaris megalocephala était voisine de Δ = − 0°, 63 avec de petites variations; d'après nos expériences, l'Ascaris était susceptible d'une régulation osmotique; il augmente de poids dans une solution hypotonique par rapport à son liquide; il y a pénétration d'eau; dans une solution hypertonique il diminue de poids (départ d'eau).

The method devised by Boeck and Drbohlav for the cultivation of E. histolytica has been successfully used for cultivating this species and various other entozoic amoebae of man and monkeys.

Various modifications of the original technique have been tried, and several improvements are here described. Among these are methods of cultivation (involving the addition of solid rice-starch to the medium) whereby (1) more luxuriant and prolonged growth of the amoebae, and (2) all stages—including encystation and excystation—in the life-cycle of E. histolytica and other species can be obtained in vitro.

Methods by which cultures of entozoic amoebae can be initiated from encysted forms have been discovered and are also described, and some indications are given for the isolation of pure strains from mixed cultures.

The influence of the accompanying bacterial flora upon the various amoebae cultivated has been studied, and is briefly discussed in the light of certain experimental findings.

Loss of infectivity to kittens has been observed in E. histolytica as an apparent result of cultivation in media containing solid starch.

Though the structure of the head and the proboscis of Hippoboscidae has been studied by many observers, their descriptions are in some respects incomplete. When, therefore, living specimens of Lynchia maura Bigot were brought to the Wellcome Bureau by Dr W. N. F. Woodland from Algiers and these were successfully bred on pigeons in captivity, I availed myself of the opportunity to reinvestigate their structure. In addition, Melophagus ovinus L. and many other forms belongs to the family were examined with special reference to the structure of the head and mouth parts.

Among the bird-parasites included in the family Hippoboscidae, are four small closely conneceted genera, in all of which the wings exhibit more or less extensive reduction and are apparently useless for the purpose of flight. In various parts of the world species belonging to one or other of three of these genera, namely Crataerina, v. Olf., Myophthiria, Rond., and Brachypteromyia, Will., infest Swifts (Micropus, Collocalia, etc.) and their nests; while the solitary representative of the fourth genus Stenepteryx, Leach, at present known is similarly parasitic on the House-Martin (Delichon urbica, L.), which, though in no wise related, is closely associated with the Common Swift in the popular mind.

In a paper read before the Royal Society of South Africa in September 1914, and published in 1915, I gave a brief description of a Herpetomonas that was found in great numbers in the cloacal mucus of Chamaeleon pumilus on Robben Island, South Africa. The flagellates were present in various stages of development in all the chamaeleons examined, i.e. about a dozen, at different seasons of the year. Attempts to cultivate the flagellates on blood agar failed owing to bacterial contamination of the media, and none were discovered in smear preparations of the lizards' spleen and liver or in blood films. Having found Herpetomonas in certain flies (Scatophaga hottentota) at that time, and it being well known that chamaeleons feed on insects, I concluded that the flagellates present in the lizard were probably derived from insects.