From the earliest ages, the Butterfly appears to have attracted the admiration of mankind; and we find it celebrated by their poets as figurative of gaiety and pleasure, and by their sages as an emblem of the human soul. It has been interwoven in one of their most beautiful allegories, and has been consecrated in our own days by several poets, though by none with such exquisite taste and moral feeling, as by the venerable Historian of the Medici. So few of those insects, generally called Butterflies, were known to Linnaeus, that he included them all in one genus, dividing them, for the most part, into natural groups. Fabricius continued this arrangement, with little variation, and has left us the description of near 1,150 species! Yet before his death, this laborious naturalist saw the absolute necessity of dividing this immense genus into many others, and left among his MSS. a sketch of his proposed arrangement, published afterwards by Illiger, and partially adopted (we venture to think also very imperfectly) by M. Latreille. The insects which are therefore now left under the old genus _Papilio_, are principally found out of Europe, and are remarkable for their richness of colouring and immense size. M. M. Latreille and Godart have described, with great precision, 146 species: it is, however, to be regretted, that they have adopted no sections or divisions to assist the student in his search after any particular species, among this extensive number. The great disadvantage of this is very obvious, and it has induced me to attempt something like a natural distribution of those insects, which, with every care to avoid an unnatural separation of kindred groups, I am fully aware, in some cases, is very artificial, and it is only offered until a greater knowledge of the larvae, &c. will enable us to fix on more substantial characters than those I have adopted. This, however, will be a work of time; and until then, I think some guide to the ready knowledge of the species, however objectionable, is better than none. Much might be said on the affinities which connect this with several other genera. Among the most striking is that existing between them and the _Noctuae_ (_N. Patroclus_ Fab.) by means of _Pap. Leilus_ Lin. which thus stands between the night and the day-flying Lepidoptera. Many of the insects placed in our division of _Graeci caudati_, are allied to _Danaus_ Lat. by the larva of both having retractile hornshaped processes, and the two genera seem still further connected by _Papilio similis_ and _dissimilis_ in one group, and by _P. Priamus_ in the other; while the clear winged species from New Holland seem to indicate an affinity with the _Heliconiae_. The laborious and important investigations of M. Savigny into the structure of the mouth of these insects are too well known, to require a more particular notice in this slight sketch of the subject. * * * * * PAPILIO Polymetus.