That the system of nature is essentially a system of types and symbols, is a truth which has not only been perceived by philosophers, but is apparent to every attentive observer of nature. It has been our endeavour, in the second volume of _Northern Zoology_, to investigate this system, and to ascertain those laws by which it is regulated. One of the results of this enquiry has been, that every genus, pre-eminently typical, contains a greater number of forms than any other; the necessary consequence of comprising within itself, representations of every division in the whole family. By this test must our present definition of the typical genus _Voluta_ be tried. We consider this particular species as the type of the whole group: according to Adanson, it is abundant on the western coast of Africa, where it is stated to vary considerably, both in its colour and in its plaits. To the same traveller we are indebted for the best account of the animal, which he describes under the name of L'Yet. It has been thought, indeed, that this is the _Voluta neptuni_, but as the interior of Adanson's L'Yet is "blanche" and that of _Neptuni_ is yellowish orange, we rather think that the French writer intended to designate the _Voluta cymbium_ of systematic authors. * * * * * * [Illustration: ENDYMION _regalis_. _Maroon banded Hair streak._] ENDYMION regalis. _Maroon-banded Hair-streak._ ---- Tribe Papiliones. Family, Polyommatidæ. Sub-family, Theclanæ. _Nob._ SUB-GENERIC CHARACTER. Palpi in one sex (male) scarcely projecting beyond the head, the last joint very minute; in the other (female) lengthened, porrect, curved downwards, the last joint as long as that which precedes it; in both obtuse and covered with close-set scales; posterior wings four tailed. ---- SPECIFIC CHARACTER. _Wings above shining blue: beneath golden emerald green, with a common black stripe, and a broad red band on the posterior wings; ocelli none._ Papilio regalis. _Cramer. Ins. Pl. 72. f. E. F._ Hesperia Endymion. _Fab. Ent. Sys. 3. 1. 268._ ---- This superb butterfly, both in size and brilliancy of colour, may vie with the Emerald Hair-streak, and both are among the most beautiful of their family yet discovered. The general colour of the under surface is of the richest golden green; the under wings being crossed by a broad bar of deep maroon, softened into pearly white. The female is known by being the largest, and by having the black margin of the upper wings much broader. Our specimens were captured in Brazil. Lat 8. 12. S. The palpi, which in the sub-genus _Arcas_ are equally long and perfect in both sexes, are very different in the male and female of the present sub-genus. In other respects there seems to be a close affinity between them. We have not had time, however, to enter upon their minute dissection. * * * * * * [Illustration: GARRULUS SORDIDUS. _Dusky bodied Jay._]