_Land-shells._--Madagascar and the adjacent islands are all rich in land-shells. The genera of Helicidæ are _Vitrina_, _Helix_, _Achatina_, _Columna_ (peculiar to Madagascar and West Africa), _Buliminus_, _Cionella_ (chiefly Oriental and South American, but not African), _Pupa_, _Streptaxis_, and _Succinea_. Among the Operculata we have _Truncatella_ (widely scattered, but not African); _Cyclotus_ (South American, Oriental, and South African); _Cyclophorus_ (mostly Oriental, with a few South African); _Leptopoma_ (Oriental); _Megalomastoma_ (Malayan and South American); _Lithidion_ (peculiar to Madagascar, Socotra, and South-West Arabia); _Otopoma_ (with the same range, but extending to West India and New Ireland); _Cyclostomus_ (widely spread but not African); and _Omphalotropis_ (wholly Oriental and Australian). We thus find the same general features reproduced in the land-shells as in the insects, and the same remarks will to a great extent apply to both. The classification of the former is, however, by no means so satisfactory, and we have no extensive and accurate general catalogues of shells, like those of Lepidoptera and Coleoptera, which have furnished us with such valuable materials for the comparison of the several faunas. _On the probable Past History of the Ethiopian Region._ Perhaps none of the great zoological regions of the earth present us with problems of greater difficulty or higher interest than the Ethiopian. We find in it the evidence of several distinct and successive faunas, now intermingled; and it is very difficult, with our present imperfect knowledge, to form an adequate conception of how and when the several changes occurred. There are, however, a few points which seem sufficiently clear, and these afford us a secure foundation in our endeavour to comprehend the rest.