518 



BRITISH LEPIDOPTERA. 



PAGE. 

 A. filipendula? . . . . . . 507 



abs. cytisi . . . . . . 511 



confluens, bipunctata, (comrnu- 

 nimacula), conjuncta .. .. 512 



grisescens, flava, .. -.513 



chrysanthemi, .. .. 514 



(vars. maunii, arctica, ochsen- 

 heimeri . . . . . . . . 515 



ramburii . . . . . . 518 



gurda 519 



laphria) . . . . . . . . 520 



A. hippocrepidis . . . . . . 532 



Anthrocerid species . . . . . . 539 



What constitutes species in this 



PAGE, 

 genus ? — General absence of 

 characteristics in early stages, 

 539. Relation to environment. 

 — Specialization to certain food- 

 plants — Consideration of A. 

 exulans, 540 ; of A. purpuralis, 

 541 ; of A. vicise, 542 ; of A. 

 lonicerae and A. trifolii. 543 ; of 

 A. filipendulae — Origin of A. 

 hippocrepidis, 544. < 'ross-pair- 

 ing rare in nature, 545. Sug- 

 gested answer to question, 546. 

 Addenda to page 369 and page 470 546 

 Errata . . . . . . . . 546 



VOL. II. 



Ch. i. Metamorphosis in Lepidoptera. 



Meaning of term " Embryonic," I. Embryonic life of thysanurid, orthopterous 

 and lepidopterous insects. — Internal and physiological changes in larva the most 

 important. — Explanation of terms — metamorphosis, 2, larva, nymph, stadium, 

 3, instar. — Composition of larval hypodermis. — Increase in weight of larva. 

 Purpose of exuviation, 4. Moulting of Sphinx ligustri, 5, Telea polyphemus, 

 Lyonetia clerckella, Eriocrania unimaculella, 6. Exuviation not only 

 external. — Moulting of a Geometrid, of Charaxes jasius, 7, Stauropus fagi, 

 8, Phalera bucephala. — Fluid between the two skins. — Variation in number 

 of moults, 10 ; sexual in Notolophus. — Remarkable experiment on Triphaena 

 comes, 12. Variation in number of moults in Acronyctids, 13 ; associated 

 with variation and plumage and habits in Arctia caia, 14. Bearing of larval 

 changes on phylogeny, 16. Change in larval appendages. Mortality among 

 S. populi at first moult. — Change of colour before pupation, 17. Homologies 

 between larval and imaginal legs. — Changes before pupation gradual, 18. 

 Inflation of intestinal canal. — Formation of pupa within larval skin. — Final 

 ecdysis, 19. Suspended pupae-—" Osborne ligament," 22. Other structures 

 involved in final process of exuviation, 24. Pupation of Phalera bucephala, 

 25. Change in spiracles immediately after pupation, 26. Change of pro- 

 portionate length between the parts of fresh pupa, 27. Modification of shape, 

 28. Pigmentary patches on larval wing-areas of Scoliopteryx libatrix. — 

 Chitinous development beneath larval skin, 29. Relation of pupal organs 

 to those of larva and imago, 30. Position of antennae, maxillae, legs and wings, 

 31. Imagines with larval head. — Pupal appendages free during pupation, 32. 

 General conclusions, 33. 



Ch. ii. Incidental Phenomena relating to Metamorphosis in Lepidoptera. 

 Abnormal length of pupal stage, 34. Causes : change of temperature, 35 ; 

 individual constitution. — Partially double-brooded species, 36. Irregularity 

 in hybrids. — Emergence of imago and parasite from the same pupa. — 

 Hydraulic pressure as an aid to emergence. — Retarded development of 

 wings, 37. 



Ch. iii. The External Morphology of the Lepidopterous Pupa. 



Pupal stage compared with that of other orders, 38. Begins before actual 

 pupation. — Pupal organs not identical with corresponding organs of imago, 

 39. Period at which imago is developed. — Homologies of the anal pupal 

 segments. — The head. — Thoracic and abdominal segments. — Number of free 

 segments, 40. The mandibles, 42 ; labrum, maxillae, maxillary palpi, 43 ; 

 labium, labial palpi, paraclypeal tubercle, 44 ; eyes, eye-flange, dorsal head- 

 piece, nose-horn, 45 ; antennae, extent of difference from those of the imago, 

 46. Wings, neuration, 47; " Poulton's line," 48. Spiracles. — Cremaster, 

 its various structures, 51. Genitalia, 52 ; male, 53 ; female, 54. Superficial 

 larval structures carried on to pupal stage. —Pupal hair-tufts, 57 ; their 

 connection with larval hairs, 58. Larval colours in pupae, 59. Pupal 

 cuticle, 60. Bloom on pupae. — Grouping by number of free segments. — 

 Dehiscence, 61. Movement of pupae-incompletae. — Movement of butterfly 

 pupae, 62. Chapman's theory of direction of pupal evolution. — Methods of 

 leaving cocoon, 63. 



