In describing the following new species from West Africa, some words of explanation are needed as to the generic names used. In the first place, it is necessary to say that the writer follows Messrs. Dyar and Knab in considering that most of the genera into which Meigen's genus Anopheles has recently been split up are not genera in any accepted sense, and should sink under the old name Anopheles. Provisionally, however, Stethomyia, Chagasia, Calvertina and Bironella are considered as distinct; as none of these genera are African, this will not affect the present paper. Lieut.-Col. A. Alcock, of the London School of Tropical Medicine, has kindly allowed me to see the manuscript of a paper on the classification of Anopheles, which he is about to publish in the Annals and Magazine of Natural History, and I have been able to concur entirely with his views; he recognises only five sub-genera of Anopheles, the sub-genus Nyssorhynchus including all those species with flat scales on thorax and abdomen, i.e., the genera Nyssorhynchus, Cellia and Neocellia of Theobald's Monograph.
Cholera, John Snow and the 2013 bicentennial meetings at the London School of Hygiene and Tropical Medicine, UK
