I. Spring Butterflies _Frontispiece_ II. Caterpillars of Papilionidæ and Hesperiidæ 6 III. Caterpillars of Nymphalidæ 18 IV. Chrysalids in Color and in Outline--Nymphalidæ 30 V. Chrysalids in Color and in Outline--Nymphalidæ, Lycænidæ, Pierinæ 44 VI. Chrysalids in Color and in Outline--Papiloninæ and Hesperiidæ 58 VII. Anosia and Basilarchia 80 VIII. Ithomiinæ, Heliconius, Dione, Colænis, and Euptoieta 88 IX. Argynnis 100 X. Argynnis 104 XI. Argynnis 108 XII. Argynnis 112 XIII. Argynnis 116 XIV. Argynnis 122 XV. Brenthis 130 XVI. Melitæa 138 XVII. Melitæa, Phyciodes, Eresia 152 XVIII. Argynnis, Brenthis, Melitæa, Phyciodes, Eresia, Synchloë, Debis, Geirocheilus 156 XIX. Grapta, Vanessa 164 XX. Grapta, Vanessa, Junonia, Anartia, Pyrameis 168 XXI. Timetes, Hypolimnas, Eunica, Callicore 178 XXII. Basilarchia, Adelpha 184 XXIII. Chlorippe 190 XXIV. Pyrrhanæa, Ageronia, Synchloë, Cystineura, Hypanartia, Victorina 196 XXV. Satyrodes, Coenonympha, Neonympha, Neominois, Erebia 204 XXVI. Satyrus 214 XXVII. OEneis 220 XXVIII. Libythea, Lemonias, Calephelis, Eumæus, Chrysophanus, Feniseca 228 XXIX. Chrysophanus, Thecla 236 XXX. Thecla, Lycæna 246 XXXI. Lycæna 256 XXXII. Lycæna, Thecla, Nathalis, Euchloë 266 XXXIII. Catopsilia, Pyrameis 272 XXXIV. Euchloë, Neophasia, Pieris, Kricogonia 280 XXXV. Tachyris, Pieris, Colias 288 XXXVI. Meganostoma, Colias 294 XXXVII. Terias, Dismorphia 298 XXXVIII. Papilio 302 XXXIX.