MOEPHOLOGY OF THE LEPIDOPTERA. 175 



the fact that he saw an imago of Acheron tia Atropos moult a complete and thin pellicle 

 after its emergence from the pupal cuticle. I have also noted a passage in Packard's 

 ' Guide to the Study of Insects ' (9th edit., 1889). It runs thus : — " In the last stage 

 of Bombus, just hefore the imago leaves its cell, the body and limbs are surrounded by a 

 thin pellicle. This pellicle also envelops the moth just before it leaves the pupal state, 

 and is cast off when it moults the pupa skin. This is probably identical with the skin 

 cast by the active sub-imago of Ephemera soon after it takes its flight " (p. 68). 



The subject is one which I hope to pursue further on another occasion, and will only 

 add here that cast pupal cuticles of Sphinx Ugustri may occasionally be met with in 

 which a thin pellicle can be raised from the inner surface. An inquiry into this and 

 other structural changes taking place during pupal life in a series of metabolic Insects 

 would probably throw light on the still obscure question of the origin and significance 

 of the quiescent pupal stage. 



BIBLIOGRAPHY. 



[The pages refer to the places in this memoir where the works named are quoted.] 



Balbiani, Ann. des Sc. Naturelles, (5), xiv. 1870, xv. 1872 [p. 171]. 



Berlese, Atti Accad. dci Lyncei, (3), Memorie, xi. 1881 [p. 173]. 



Bessels, Zeitschrift fur wiss. Zoologie, xvii. 1867 [p. 151, p. 156 note, p. 159 and note]. 



Brauer, Systematisch-Zool. Studien, Sitzb. Akad. Wien, xci. Abth. 1, 1885 [p. 173]. 



Buckler, Larvae of Brit. Butterflies and Moths, Ray Society, i. 1886 [p. 158]. 



Burgess, Anniversary Memoirs of the Boston Nat. Hist. Soc. 1880 [p. 150, and note]. 



Cholodkowsky, Zeitschrift fur wiss. Zoologie, xlii. 1885 [p. 149, p. 149 note, p. 151 note]. 



Curtis, British Entomology, Description of Plate 147 [p. 174]. 



De Lacaze-Duthiers, Ann. des Sc. Naturelles, (3), xix. 1853 [p. 151], and (3),xviii. 1852 [p. 173 note]. 



Doyere, Ann. des Sc. Naturelles, (2), vii. 1837 [p. 173 note]. 



Emerton, Proc. Boston Soc. Nat. Hist, xxiii. 1888 [p. 151 note], 



Graber, Die Insekten, ' Naturkrafte ' Series, xxii. 1877 [p. 151]. 



Graber, Morphol. Jahrbuch, xiii. 1888 [p. 151 note]. 



Herold, Entwickelungsgeschichte der Schmetterlinge, 1815 [p. 147, p. 152 note, p. 154 and note]. 



Kirby and Spence, Introduction to Entomology, iii. 1826 [p. 152]. 



Kowalewsky, Mem. Acad. Imp. St. Petersbourg, (7), xvi. 1871 [p. 151]. 



Kunckel, Comptes Rendus, xci. 1880 [p. 153]. 



Lubbock, Trans. Linn. Soc. xxii. pt. 3, 1858 [p. 152]. 



Lyonet, Traite de la Chenille qui rouge le bois du Saule, 1762 [p. 152]. 



Miall and Denny, The Cockroach, Studies in Comp. Aiiat. iii. 1886 [p. 171 and note]. 



Muller, W., Spengel's Zool. Jahrbiicher, i. 1886 [p. 152]. 



Nussbaum, Zool. Anzeiger, v. 1882 [p. 171]. 



Packard, American Naturalist, xix. 1885 [p. 151]. 



Packard, Guide to the Study of Insects, 1889 [p. 175]. 



SECOND SEBIES. — ZOOLOGY, VOL. V. 27 



