Alligators, their peculiarity to S. America, 143. Alpine species, some peculiarly so, 40. Altitude and latitude, sometimes reciprocal, 35, 114. _Amyeterus_, its concentration in Australia, 143. Amyot, M., his 'Methode Mononomique,' 164. Analogies, Lord Bacon on the importance of, 13; why necessary to be studied, 14. Analogy, argument from, 10, 11, 12. _Anchomenus marginatus_, Linn., slightly modified in Madeira, 38. Andes, dissimilarity of the fauna on the opposite sides of the, 146. _Anobium striatum_, Oliv., unaffected by climate, 31. Antennae, joints of, said occasionally to vary, 96. _Anthicus bimaculatus_, Illig., variability of, near the sea, 63. _---- fenestratus_, Schmidt, slightly modified in Madeira, 38. _---- humilis_, Germ., variability of in salt places, 63. _---- instabilis_, Hoffm., pallid hue of, 64. _Anthonomus ater_, Mshm, very small in Lundy Island, 58, 73. _Aphelocheirus aestivalis_, Fabr., the hemelytra of, sometimes fully developed, 100. _Aphodius nitidulus_, Fabr., paler in Madeira than in Europe generally, 65. _Aphodius plagiatus_, Linn., usually black in England, 61; two distinct states of, indicated, 105. _Apocyrtus_, its concentration in the Philippine Islands, 143. _Apotomus_, common to Madeira and Sicily, 139. _Argutor_, always apterous in Madeira, 82; trophi of, almost identical with those of _Calathus_, 175. Armadillos, their peculiarity to S. America, 143. Armitage, Mr., on _Cicindela fasciatopunctata_ from Mount Olympus, 41. Arrangement, a lineal one is not indicated in Nature, 163. Atlantic continent, Prof. E. Forbes on the former existence of, 137. Atlantis of the ancients, the impossibility of its being identified with a former Atlantic region, 140; perhaps the New World, 141. _Atlantis_, the genus, a modification of _Laparocerus_, 143. Azores, the colonization of, by two Madeiran _Helices_, 133. Bacon, Lord, on the importance of analogies, 13; on the Atlantis of the ancients, 141; on the necessity of observation for forming science, 159. Banksias, their concentration in Australia, 142. Barriers, natural, the difference between primary and recent, 145; their hindrance to insect diffusion, 145. _Bembidium Atlanticum_, Woll., paler in Porto Santo than in Madeira, 66; the variations to which it is subject, 107, 108. _---- bistriatum_, Dufts., paler in saline districts, 62. _---- ephippium_, Mshm, pallid hue of, 64. _---- obtusum_, Sturm, varies in southern latitudes, 33. _---- pallidipenne_, Illig., pallid hue of, 64. _---- saxatile_, Gyll., variety of, on the south coast of England, 60. _---- Schmidtii_, Woll., perhaps a state of _B. callosum_, 66. _---- scutellare_, Germ., pallid hue of, 64. _---- tabellatum_, Woll., perhaps a state of _B. tibiale_, 66. _Berginus_, common to Madeira and Sicily, 139.