_Coleoptera._--This sub-region is very rich in many groups of Coleoptera, of which a few only can be noticed here. Among Carabidæ it possesses _Procerus_ and _Procrustes_, almost exclusively, while _Brachinus_, _Cymindis_, _Lebia_, _Graphipterus_, _Scarites_, _Chlænius_, _Calathus_, and many others, are abundant and characteristic. Among Lamellicorns--Copridæ, Glaphyridæ, Melolonthidæ, and Cetoniidæ abound. Buprestidæ are plentiful, the genera _Julodis_, _Acmæodera_, _Buprestis_, and _Sphenoptera_ being characteristic. Among Malacoderms--Cebrionidæ, Lampyridæ, and Malachiidæ abound. The Tenebrioid Heteromera are very varied and abundant, and give a character to the sub-region. The Mylabridæ, Cantharidæ, and Oedemeridæ are also characteristic. Of the immense number of Curculionidæ--_Thylacites_, _Brachycerus_, _Lixus_, and _Acalles_ may be mentioned as among the most prominent. Of Longicorns there are few genera especially characteristic, but perhaps _Prinobius_, _Purpuricenus_, _Hesperophanes_, and _Parmena_ are most so. Of the remaining families, we may mention Clythridæ, Hispidæ, and Cassididæ as being abundant. {206}_The Mediterranean and Atlantic Islands._--The various islands of the Mediterranean are interesting to the student of geographical distribution as affording a few examples of local species of very restricted range, but as a rule they present us with exactly the same forms as those of the adjacent mainland.[6] Their peculiarities do not, therefore, properly come within the scope of this work. The islands of the Atlantic Ocean belonging to this sub-region are, from their isolated position and the various problems they suggest, of much more interest, and their natural history has been carefully studied. We shall therefore give a short account of their peculiar features. Of the three groups of Atlantic islands belonging to this sub-region, the Canaries are nearest to the Continent, some of the islands being only about fifty miles from the coast of Africa. They are, however, separated from the mainland by a very deep channel (more than 5,000 feet), as shown on our general map. The islands extend over a length of 300 miles; they are very mountainous and wholly volcanic, and the celebrated peak of Teneriffe rises to a height of more than 12,000 feet. The small Madeira group is about 400 miles from the coast of Morocco and 600 from the southern extremity of Portugal; and there is a depth of more than 12,000 feet between it and the continent. The Azores are nearly 1,000 miles west of Lisbon. They are quite alone in mid-Atlantic, the most westerly islands being nearer Newfoundland than Europe, and are surrounded by ocean depths of from 12,000 to 18,000 feet. It will be convenient to take these islands first in order.