The progress of applied Entomology is mainly visible in the discovery of practical means for the destruction of insects injurious to cultivated plants, and in the minute determination of the various stages of the growth and development of such insects. More recently the parasites of insect pests, both of vegetable and animal origin, have also largely attracted attention. But physiological research, so far as injurious insects are concerned, has almost entirely been overlooked and neglected; although this line of enquiry affords obvious opportunities for arriving at tbe very essence of the whole matter, and should indeed be made one of the main starting points in the study of insect pests.

In pursuing my studies of the genital armature of the tsetse-flies, I have been fortunate in securing some valuable and interesting material from various parts of the African continent which has enabled me to offer a further contribution on the specific characters of the recently discovered Glossina austeni, Newst., from British East Africa; to present a detailed account of the armature of the apparently rare G. fuscipleuris, Aust., and to clear up some doubtful points in regard to the structural details of the male genital armature in G. longipennis, Corti. Later I hope to be able to offer some further remarks on G. palpalis, R.D., especially in regard to the colour and structural variations existing in this species. Meanwhile I may here state, for the guidance of the student, that G. fuscipes, Newst., which was described by me as a distinct species, must sink as a well-marked race of G. palpalis.

In making a critical examination of the palpi of the various species of phlebotomus described in this paper, I have found that the third* segment of the palpi in all of them is provided with a compound group of minute and curiously modified spines. In P. minutus (fig. 1c) they are somewhat squamiform and the pedicel is, so far as I can ascertain, extremely short; in P. papatasii (fig. 1d) they are distinctly spathuliform, with the pedicel long and strongly curved. In P. squamipleuris (fig. 1i) the spines are similar to those found in P. papatasii, but they appear to be more gradually dilated distally and have relatively shorter pedicels. These organs are common to both sexes and are probably sensory in function; but they are so easily deciduous that they can rarely be seen, though the position occupied by them is generally indicated by a compound group of circular cicatrices clearly showing the point of attachment of the spines with the integument.

Most of the species of Leiognathus are parasitic on small mammals (bats, rodents, etc.), others occur on birds and a few also on reptiles. A number of the species of this genus have been described under the name Liponyssus, butpersonally I do not think that Liponyssus setosus, Kolenati (the type and first described species of the genus Liponyssus) falls into the same natural genus as the species described by recent authors under that generic name or under the name Leiognathus. On the other hand, Kolenati's genera Ischoronyssus, Macronyssus, Lepronyssus, Steatonyssus and Pimelonyssus certainly seem to me to be congeneric with Leiognathus, Cn., and ultimately one of these names will have to replace Canestrini's.

When, early in the present year, Dr. A. Ingram sent in to the Entomological Research Committee his collection of larvae and bred adults of culicinae from Bole, Northern Territories, Gold Coast, the writer decided to describe these as soon as possible, and the opportunity seemed favourable to include a thorough revision of the known larvae of the African culicinae. The results of this work are given in the following tables. The difficulties of classification might have been considerable, but for the valuable pioneer work of Messrs. Dyar and Knab* in America, and the present author is glad to express his indebtedness to these writers, and would like to add his testimony, if any were needed, to the soundness of their general classification. The paper by Wesché† in this journal is also very important, as it is the only one devoted to a study of the larvae of African culicidae. Figures of most of the species not illustrated here will be found in it.

It is generally admitted that the ability to determine the species of Anopheles by an examination of their larvae would place a valuable weapon in the hands of the practical sanitarian in tropical countries. In the investigation of an area for the determination of the Anopheles present, it frequently happens that, on account of their habit of concealment by day, adult mosquitos are difficult to find, whereas their breeding places may be located readily. If the larvae are transported to a distance they commonly do not develop further, and so, failing the specific identification of the larvae themselves, valuable information is lost. It is therefore very desirable to know whether, and to what extent, any of the characteristics of such larvae may safely be employed in determining their species.

The following notes and descriptions are based on material received by the Entomological Research Committee, who have kindly presented the types of the new species to the National Collection.

The types of the eight new species described in the present instalment are in the British Museum (Natural History). The following list shows at a glance the countries in which these additions to our knowledge of the blood-sucking flies of Africa have been obtained.

♀.—Length (1 specimen) 3·5 mm.; width of head 1·4 mm.; width of front at vertex 0·6 mm.; length of wing 5 mm.