Black Rat, nearly exterminated in England, 178. _Blemus areolatus_, Creutz., paler in brackish places, 62. _Bolitochara assimilis_, Kby, smallness of, in the Scilly Islands, 73. _Boromorphus_, common to Madeira and Sicily, 139. _Brachinus crepitans_, Linn., two distinct sizes of, frequently indicated, 105. _Bradycellus fulvus_, Mshm, apterous in Madeira, 85. Bread-fruit Trees, their peculiarity to the South Sea Islands, 142. _Calathus_, apterous in Madeira, 82; its trophi almost identical with those of _Pristonychus_, 175. _---- complanatus_, Koll., varies from altitude, 39; variety of, on one of the Madeira Islands, 88. _---- fuscus_, Fabr., slightly modified in Madeira, 38, 85. _Calathus melanocephalus_, Linn., smallness of, in the Scilly Islands, 73. _---- mollis_, Mshm, variable in its wings, 43; lurid colour of, 64. Calcareous soils, effect of, on the aspect of insects, 66. Calceolarias, their concentration on the Andes, 142. _Calosoma_, a species of, ten miles from shore, 147; the genus, mergescgradually into _Carabus_, 175. _---- Syncophanta_, Linn., its power of crossing the sea, 147. Canary Islands, migratory direction of their insect population, 119. _Carabidae_, inconstant in their organs of flight, 43; family of, nearly similar throughout in its oral organs, 174. _Carpophilus hemipterus_, Linn., unaffected by climate, 31. _Caulotrupis conicollis_, Woll., large size of, on one of the Madeira Islands, 88, 109. _---- lucifugus_, Woll., varies from isolation, 90, 109. Causes, never final ones which we investigate, 191. _Centrinus_, its concentration in S. America, 143. _Ceutorhynchus contractus_, Mshm, smallness of, in Lundy Island, 59, 73. _Cholovocera_, common to Madeira and Sicily, 139. _Choreius ineptus_, Westw., on a winged state of, 44. _Chorosoma miriforme_, the development of the wings of, 100. _Chrysomela_, apterous in Madeira, 82. _Chrysomelae_, vary from altitude, 41. _Chrysomelidae_, almost absent in Tierra del Fuego, 47. _Cicindela fasciatopunctata_, Germ., a state of _C. sylvatica_ 41. _Cicindelidae_, often variable, 41. _Cillenum laterale_, Sam., lurid hue of, 64. _Cimex apterus_, Linn., the development of the wings of, 100. _---- lectularius_, Linn., on the development of the wings of, 45. _Cistela sulphurea_, Linn., its variability near the sea, 60. _Clausilia deltostoma_, Lowe, a Porto-Santan form of, 134. Climatal modifications significant, although small, 42. Climate, not important as a disturbing cause, 23, 24, 31, 32, 42. Clouded-yellow Butterfly, unaffected by climate, 31. _Clypeaster pusillus_, Gyll., differs slightly in Madeira, 65. Coast, inconstancy of insects in the vicinity of the, 57. _Coccinella 7-punctata_, Linn., unaffected by climate, 31. _Colias Edusa_, Fabr., unaffected by climate, 31.