{265}Here, too, we find some interesting relations with the Oriental region on the one side, and the Neotropical on the other. The snakes of the family Homalopsidæ have a wide range, in America, Europe, and all over the Oriental region, but are confined to West Africa in the Ethiopian region. _Dryiophis_ (Dryiophidæ) and _Dipsadoboa_ (Dipsadidæ) on the other hand, are genera of tropical America which occur also in West Africa. The family of lizards, Acontiadæ, are found in West and South Africa, Ceylon, and the Moluccas. The family of toads, Engystomidæ, in West and South Africa and the whole Oriental region; while the Phryniscidæ inhabit tropical Africa and Java. _Insects._--We have here a large number of peculiar genera. There are 10 of butterflies, _Lachnoptera_, _Amphidema_, and _Catuna_ belonging to the Nymphalidæ, while four others are Lycænidæ. The genus _Euxanthe_ is common to West Africa and Madagascar. Of Coleoptera there are 53 peculiar genera; 20 are Carabidæ, 2 Lucanidæ, 12 Cetoniidæ, 3 Prionidæ, 16 Cerambycidæ, and 34 Lamiidæ. Besides these there are 4 or 5 genera confined to West Africa and Madagascar. _Land Shells._--West Africa is very rich in land shells, but it does not appear to possess any well-marked genera, although several of the smaller groups or sub-genera are confined to it. Helicidæ of the genera _Nanina_, _Buliminus_ and _Achatina_ are abundant and characteristic. _Islands of the West African Sub-region._--The islands in the Gulf of Guinea are, Fernando Po, very near the main land, with Prince's Island and St. Thomas, considerably further away to the south-west. Fernando Po was once thought to be a remarkable instance of an island possessing a very peculiar fauna, although close to the main land and not divided from it by a deep sea. This, however, was due to our having obtained considerable collections from Fernando Po, while the opposite coast was almost unknown. One after another the species supposed to be peculiar have been found on the continent, till it becomes probable, that, as in the case of other islands similarly situated, it contains no peculiar species whatever. The presence of numerous mammalia, among which are baboons, lemurs, _Hyrax_, and {266}_Anomalurus_, shows that this island has probably once been united to the continent. Prince's Island, situated about 100 miles from the coast, has no mammals, but between 30 and 40 species of birds. Of these 7 are peculiar species, viz., _Zosterops ficedulina_, _Cuphopterus dohrni_ (a peculiar genus of Sylviidæ), _Symplectes princeps_, _Crithagra rufilata_, _Columba chlorophæa_, _Peristera principalis_, and _Strix thomensis_.