The Shrews have a wide distribution, being found throughout every region except the Australian and Neotropical; although, as a species is found in Timor and in some of the Moluccas, they just enter this part of the former region, while one found in Guatemala brings them into the latter. A number of species have recently been described from India and the Malay Islands, so that the Oriental region is now the richest in shrews, having 28 species; the Nearctic comes next with 24; while the Ethiopian has 11, and the Palæarctic 10 species. The sub-genera are _Crossopus_, _Amphisorex_, _Neosorex_, _Crocidura_, _Diplomesodon_, _Pinulia_, _Pachyura_, _Blarina_, _Feroculus_, _Anausorex_. _Extinct Species._--Several species of _Sorex_ have been found fossil in the Miocene of the South of France, as well as the extinct genera _Mysarachne_ and _Plesiosorex_; and some existing species have occurred in Bone Caves and Diluvial deposits. _General Remarks on the Distribution of the Insectivora._ The most prominent features in the distribution of the Insectivora are,--their complete absence from South America and Australia; the presence of _Solenodon_ in two of the West Indian islands while the five allied genera are found only in Madagascar; and the absence of hedgehogs from North America. If we consider that there are only 135 known species of the order, 65 of which belong to the one genus _Sorex_; while the remaining 26 genera contain only 70 species, which have to be classed in 8 distinct families, and present such divergent and highly specialized forms as _Galeopithecus_, _Erinaceus_, _Solenodon_, and _Condylura_, it becomes evident that we have here the detached fragments of a much more {192}extensive group of animals, now almost extinct. Many of the forms continue to exist only in islands, removed from the severe competition of a varied mammalian population, as in Madagascar and the Antilles; while others appear to have escaped extermination either by their peculiar habits--as the various forms of Moles; by special protection--as in the Hedgehogs; or by a resemblance in form, coloration, and habits to dominant groups in their own district--as the Tupaias of Malay which resemble squirrels, and the Elephant-shrews of Africa which resemble the jerboas. The numerous cases of isolated and discontinuous distribution among the Insectivora, offer no difficulty from this point of view; since they are the necessary results of an extensive and widely-spread group of animals slowly becoming extinct, and continuing to exist only where special conditions have enabled them to maintain themselves in the struggle with more highly organized forms.