_---- Delphinula_, Lowe, the Madeiran representative of _H. tectiformis_ in Porto Santo, 129. _---- discina_, Lowe, a form of _H. polymorpha_, 133. _---- erubescens_, Lowe, its powers of diffusion greater than those of its allies, 133; sensitive to external influences, 134. _---- fluctuosa_, Lowe, its extinction in Porto Santo, 131. _---- hirsuta_, Say, two distinct states of, 106. _---- lapicida_, Linn., its extinction in Porto Santo, 131. _---- latens_, Lowe, the Madeiran representative of _H. obtecta_ in Porto Santo, 129. _---- lincta_, Lowe, the common Madeiran form of _H. polymorpha_, 134. _---- Lowei_, Pfr., perhaps a gigantic state of _H. Portosanctana_, 106. _---- papilio_, Lowe, a form of _H. polymorpha_, 133. _---- paupercula_, Lowe, its powers of diffusion greater than those of its allies, 133. _---- polymorpha_, Lowe, sensitive to external influences, and of great diffusive powers, 133. _---- Portosanctana_, Sow., its peculiarity to Porto Santo, 129. _---- pulvinata_, Lowe, a form of _H. polymorpha_, 133. _---- saccharata_, Lowe, a local state of _H. polymorpha_, 134. _---- senilis_, Lowe, the Dezertan form of _H. polymorpha_, 134. _---- squalida_, Lowe, the Madeiran representative of _H. depauperata_ in Porto Santo, 129. _---- tiarella_, Webb, its sedentary nature, 128. _---- undata_, Lowe, its peculiarity to Madeira proper, 129. _---- Vulcania_, Lowe, its peculiarity to the Dezertas, 129. _---- Wollastoni_, Lowe, sedentary nature of, 132. _Helobia nivalis_, Payk., perhaps a state of _H. brevicollis_, 40. _Helops_, always apterous in Madeira, 82. _---- confertus_, Woll., varies from altitude, 39. _---- futilis_, Woll., varies from isolation, 109. _---- testaceus_, Kuest., pallid hue of, 64. _---- Vulcanus_, Woll., large size of, on one of the Madeira Islands, 88. Henfrey, Prof., on disturbing agents, 8. Herschel, Sir John, on the requisites for an observer, 12. _Hipparchia Semele_, Linn., has a distinct aspect in Madeira, 34. _Hipporhinus_, its concentration in S. Africa, 143. Holme, Mr., on _Olisthopus rotundatus_ in the Scilly Islands, 58, 102; on a winged state of _Phosphuga atrata_, 102. _Holoparamecus_, common to Madeira and Sicily, 139. _---- Niger_, Aube, different in Madeira and Sicily, 33. Hooker, Dr., on the insects of Kerguelen's Land, 86. Humboldt, his notice of Sphinxes and flies high up on the Andes, 149. Humming-Birds, their peculiarity to S. America and the W. Indies, 142. _Hydrobius_, apterous in Madeira, 82; the capture of, out at sea, 150. _Hydrometridae_, on the development of the wings of, 100. _Hydroporus_, the capture of, out at sea, 150. _---- confluens_, Fabr., unaffected by climate, 31. _Hypsonotus_, its concentration in S. America, 143. Influence of climate not important, 23.