_Mesites_, a modification of _Cossonus_, 144. _---- Maderensis_, Woll., its near relationship to the _M. Tardii_, 141. _---- Tardii_, Curtis, its variability near the coast, 58. 'Methode Mononomique,' the unsoundness of, 164-168. Migratory powers, slowness of, in the Madeiran _Helices_, 130-132. ---- progress, direction of, in the Madeiran animals, 120, 135. Mimosas, their concentration in Australia, 142. Mollusca, Terrestrial, often present two distinct states, 106. _Moluris_, its concentration in S. Africa, 143. _Monochelus_, its concentration in S. Africa, 143. Mountain-chains, their hindrance to insect-diffusion, 145. Mountain-tops, either very prolific in insect life, or else barren, 115. _Mus Rattus_, almost exterminated in England, 178. _Mycetoporus pronus_, Erichs., two distinct states of, indicated, 106. Myrtles, their concentration in Australia, 142. Naturalist, the, what his province to investigate, 158. Nature, not irregular because presenting occasional anomalies, 94. _Naupactus_, its concentration in S. America, 143. _Nebria complanata_, Linn., unusually pale near Bordeaux, 33; pallid hue of, 64. New World, some of its insects perhaps but states of those of the Old, 37. Nomenclature, a binomial system the only true one, 164, 168. _Notaphus_, the capture of, out at sea, 150. _Notiophili_, extremely variable, 40. _Notiophilus geminatus_, Dej., large size of, on one of the Madeira Islands, 88. Observation, indispensable in natural science, 20, 159, 192. Ocean, the, its hindrance to insect-diffusion, 145. _Ochthebius marinus_, Payk., lurid hue of, 64. _Olisthopus_, apterous in Madeira, 82. _---- Maderensis_, Woll., large state of, on one of the Madeira Islands, 88, 89. _---- rotundatus_, Payk., very small in the Scilly Islands, 58, 73; subapterous in the Scilly Islands, 102. _Omaseus nigerrimus_, Dej., a form of _O. aterrimus_, 33. _Omias Waterhousei_, Woll., large state of, on one of the Madeira Islands, 88, 109. _Oncocephalus griseus_, development of the wings of, 101. _Othius_, apterous in Madeira, 82. Ourangs, their peculiarity to the Indian Islands, 143. _Oxyomus_, a modification of _Aphodius_, 144. _Pachymerus brevipennis_, the development of the wings of, 100. _Pachyrhynchus_, its concentration in the Philippine islands, 143. Painted-Lady Butterfly, unaffected by climate, 32. _Papilio Machaon_, Linn., unaffected by climate, 31. _Paropsis_, its concentration in Australia, 143. Patagonia, insects of, distinct from those of Tierra del Fuego, 47, 48. _Patrobus septentrionis_, Dej., has been supposed to be a state of _P. excavatus_, 40. _Pecteropus_, its maximum attained in the Canaries, 124. _---- Maderensis_, Woll., varies from altitude, 39. _---- rostratus_, Woll., varies from isolation, 90.