Wallace, A. R.; introduction of the expression “seasonal dimorphism,” 1; on the dull colours of female butterflies, 8; sexual dimorphism of butterflies, 32; local variation in colour, 60; comparison of seasonal dimorphism with alternation of generations, 80; the bright colours of caterpillars, 293; on adaptation, 589; on variability, 654, 658. Wallace, Dr., colour changes in larva of _B. Cynthia_, 7. Walsh, B. D., phytophagic variation, 305. Weale, J. P. M., on the young larvæ of _Pap. merope_ and _Gyn. Isis_, 166; the larva of _Ach. Atropos_ in S. Africa, 263; habits of S. African Sphinx-caterpillars, 290. Weir, J. Jenner, the colour variations of _Hip. semele_, 8; experiments with brightly-coloured, hairy, and spiny caterpillars, 336. Westwood, Prof. J. O., seasonal dimorphism of _Eph. punctaria_, 4; figure of caterpillar referred to, 243; gynandromorphic butterfly, 249. White colour, protection afforded by, 6, 659, 661. White, Dr. F. B., local variation in British Lepidoptera, 60; young _Notua_ larvæ, 166. Wiedersheim, on the anatomy of _Amblystoma_, 577; habits of _Geotriton fuscus_, 617; anatomy of Axolotl, 623. Wigand, on the non-increase in size of the gooseberry, 654. Wilde, O., on larva of _Dei. Galii_, 213; of _Dei. Hippophaës_, 218; larval characters of the _Notodontidæ_, 443. Wilson, Owen, figure of larva of _Ch. porcellus_ referred to, 188. Wöhler, Prof., the synthesis of urea, 643. Wood, T. W., photographic sensitiveness of Lepidopterous pupæ, 405. Würtemberger, on Ammonites, 275. Y. Yenisei, Swedish Expedition referred to, 20. Z. Zeller, P. C., seasonal dimorphism of _Pl. Polysperchon_ and _Pl. Amyntas_, 2; of Italian butterflies, 75. ERRATA. Page 81, line 8 from top, and throughout essay, for “_Daphnidæ_” read “_Daphniidæ_.” Page 95, line 3 from bottom, for “Daphnoidea” read “Daphniacea.” Page 166, line 7 from bottom (note), for “p. 438” read “p. 433.” Page 245, line 17 from bottom (note), for “Ställ” read “Stoll.” Page 263, after the word “insects” (bottom line of note), add, “but the whole marking is suggestive of distastefulness.” Page 296, line 3 from bottom, for “Stähelina--collector” read “Stähelin--a collector.” Page 305, line 5 from bottom (note), for “In 1869” read “In 1865.” Page 434, bottom line of note, for “Geometræ” read “Bombycidæ.” Page 494, line 2 from top, for “from which a larval form” read “from a larval form which.” Page 542, line 12 from top, for “_Dione Vanilla_” read “_Dione Vanillæ_.” Page 544, line 15 from bottom, for “_Siderome_” read “_Siderone_.” Transcriber’s Notes Punctuation, hyphenation, and spelling were made consistent when a predominant preference was found in this book; otherwise they were not changed.