It thus appears that every species of Papilio exhibits this peculiar form in a greater or less degree, except one, P. Polyphontes, allied to P. Diphilus of India and P. Polydorus of the Moluccas. This fact I shall recur to again, as I think it helps us to understand something of the causes that may have brought about the phenomenon we are considering. Neither do the genera Ornithoptera and Leptocircus exhibit any traces of this peculiar form. In several other families of Butterflies this characteristic form reappears in a few species. In the Pieridae the following species, all peculiar to Celebes, exhibit it distinctly:-- 1. Pieris Eperia compared with P. Coronis (Java). 2. Thyca Zebuda " " Thyca Descombesi (India). 3. T. Rosenbergii " " T. Hyparete (Java). 4. Tachyris Hombronii " " T. Lyncida. 5. T. Lycaste " " T. Lyncida. 6. T. Zarinda " " T. Nero (Malacca). 7. T. Ithome " " T. Nephele. 8. Eronia tritaea " " Eronia Valeria (Java). 9. Iphias Glaucippe, var. " " Iphias Glaucippe (Java). The species of Terias, one or two Pieris, and the genus Callidryas do not exhibit any perceptible change of form. In the other families there are but few similar examples. The following are all that I can find in my collection:-- Cethosia AEole compared with Cethosia Biblis (Java). Eurhinia megalonice " " Eurhinia Polynice (Borneo). Limenitis Limire " " Limenitis Procris (Java). Cynthia Arsinoe, var. " " Cynthia Arsinoe (Java, Sumatra, Borneo) All these belong to the family of the Nymphalidae. Many other genera of this family, as Diadema, Adolias, Charaxes, and Cyrestis, as well as the entire families of the Danaidae, Satyridae, Lycaenidae, and Hesperidae, present no examples of this peculiar form of the upper wing in the Celebesian species.