INDEX. 305 



Sitophilus oryzte, Linn., unaffected by climate, 31. 



Sloths, their peculiarity to S. America, 143. 



Species, definition of the term, 4 ; familiar explanation concerning 

 the nature of, 161, 162 ; hmitation of, how to be attempted, 192 ; 

 limits of, real, though often difficult to trace out, 193 ; in a cer- 

 tain sense both unstable and permanent, 194. 



Specific centres of creation, 5. 



Sphinx Convolvuli, Linn., its introduction into Madeira probably 

 recent, 74. 



Spinola, on one of the Reduviadce, 101; on Oncocephalus griseus, 

 101. 



Stapelias, their concentration in Southern Africa, 142. 



States, large and small ones indicated in some insects, 105. 



Stature of insects, smaller in islands than on continents, 70. 



Stenolophus Skrimshiranus, Steph., perhaps a state of S. Teutonus, 

 63. 



Stenus Heeri, WoU., two distinct states of, indicated, 106. 



Structural characters, seldom variable in the Insecta, 95. 



Subsidences, the effect of, on insect life, 114. 



Swallow-Tail Butterfly, unaffected by climate, 31. 



Syncalypta, apterous in Madeira, 82. 



TacTiyporus nitidicollis, Steph., perhaps a state of T. ohtusus, 33. 



Tarphii, their economy in the Madeira Group, 121. 



Tarphius, its maximum attained in Madeira proper, 121 ; common 



to Madeira and Sicily, 139. 



gibbulus. Germ., the Sicilian exponent of the genus, 123. 



Lowei, Well., of a more adaptive natm-e than its allies, 122. 



Tarus, always apterous in Madeira, 82. 



lineatus, Schbnh., assumes a distinct state in Madeira, 65. 



Telephorus testaceus, Linn., its variability in Lundy Island, 59. 

 Thompson, Mr., on the reptiles of Ireland, England, and Belgium, 



136. 

 Thorictus, common to Madeira and Sicily, 139. 

 Tierra del Fuego, insects of, 47 ; has many characters in common 



with Madeira, 48—51. 

 Time, an important item in the question of modifications, 77- 

 Toucans, their peculiarity to S. America and the W. Indies, 142. 

 Transmutation-theory, unsoundness of the, 186 — 189 ; how it took 



its rise, 190. 

 Trechus, always apterous in Madeira, 82. 



alticola, Woll., perhaps a state of T. custos, 39. 



lapidosus. Daws., pallid hue of, 64. 



Tree-Porcupines, their peculiarity to S. America, 143. 

 Tribolium ferrugineum, Fabr., unaffected by climate, 31. 

 Trogosita mauritanica, Linn., unaffected by climate, 31. 



