210 ZOOLOGICAL GEOGRAPHY. [PART Ill. 
any other, and its comparatively remote situation, combined with 
its luxuriant vegetation, have been favourable to the develop- 
ment and increase of the peculiar forms which characterize all 
the Atlantic islands in a more or less marked degree. A con- 
sideration of some of its peculiarities will, therefore, best serve 
to show the bearing of the facts presented by the insect fauna of 
the Atlantic islands, on the general laws of distribution. The 
711 species of beetles now known from the Madeira group, 
belong to 236 genera; and no less than 44 of these genera are 
not European but are peculiar to the Atlantic islands. Most of 
them are, however, closely allied to European genera, of which 
they are evidently modifications. A most curious general feature 
presented by the Madeiran beetles, is the total absence of many 
whole families and large genera abundant in South Europe. 
Such are the Cicindelide, or tiger beetles ; the Melolonthide, or 
chafers; the Cetoniide, or rose-chafers; the Eumolpide and 
Galerucide, large families of Phytophagous, or leaf-eating beetles; 
and also the extensive groups of Elateride and Buprestide, 
which are each represented by but one minute species. Of 
extensive genera abundant in South Europe, but wholly absent 
in Madeira, are Carabus, Rhizotrogus, Lampyris, and other 
genera of Malacoderms; Otiorhynchus, Brachycerus, and 20) 
other genera of Curculionide, comprising more than 300 South 
European and North African species; Pimelia, Tentyra, Blaps, 
and 18 other genera of Heteromera, comprising about 550 species 
in South Europe and North Africa; and Zimarcha, containing 
44 South European and North African species. 
Another most remarkable feature of the Madeiran Coleoptera 
is the unusual prevalence of apterous or wingless insects. This 
is especially the case with groups which are confined to the 
Atlantic islands, many of which consist wholly of wingless 
species; but it also affects the others, no less than twenty-two 
genera which are usually or sometimes winged in Europe, having 
only wingless species in Madeira; and even the same species 
which is winged in Europe becomes, in at least three cases, 
wingless in Madeira, without any other perceptible change having 
taken place. But there is another most curious fact noticed by 
