_Type_, Papilio Jasius. _Auct._ ---- SPECIFIC CHARACTER. _Wings above blackish, with a broad, common band, and an anterior spot of straw colour; beneath, having the band greenish, and margined with chesnut._ Papilio Athamas. _Cramer_, Pl. 89. f. C. D. ---- We can communicate but little on this elegant Butterfly, of which our figures represent the female: the other sex is known by having the straw coloured band much narrower; on the under surface this colour is prismatic; changing, in some lights, to a delicate pea green. The great size and thickness of the thorax, intimate a powerful and rapid flight. The group is Oriental; but one species, the beautiful and rare _Pap. Jasius._ Lin. we have captured in the Island of Sicily, the most southern part of Europe. As we have not yet completed the analysis of this family of Butterflies, we know not the rank or true affinities of the present group. It is evidently either one of the lowest types of form, or a sub-genus. We have received both sexes of these insects from Java, where the species appears to be common. The resemblance of this group, to _Rhetus_ and _Marius_, would seem to indicate points of strong natural analogy. We adopt the original specific name of Cramer: for we cannot, at this moment, trace the species in the voluminous works of Fabricius. * * * * * * [Illustration: GEOTROCHUS _pileus_. _Cap Land-Trochus._] GEOTROCHUS pileus. _Cap-shaped Land-trochus._ ---- Order Phytophages. _Swains._ Tribe ---- SUB-GENERIC CHARACTER. Shell pyramidical, each volution, reckoning from the base, gradually diminishing and forming a conic spire, basal volution depressed, margin of the outer lip reflected and entire. ---- SPECIFIC CHARACTER. _Shell trochiform, smooth, generally banded with reddish and yellowish bands: volutious convex._ Trochus Pileus. _Chemnetz. Pl. 122. f. 1046-7-8._ Helix pileus. _Dillwyn. p. 933. No. 106._ _Lister. Tab. 14. f. 11._ In Mus. Nost. ---- Although this shell, in artificial arrangements, may be very well placed among the sub-divisions of _Helix_ or _Bulimus_, we feel persuaded that it is, _naturally_, the type of a Sub-genus: we have no hesitation, therefore, in recording it as such. Another species, sharply carinated, semi-transparent, and of a milky whiteness, we discovered in Brazil: and we are thus led to conclude that the habitat of _Geotrochus pileus_, which no author has yet mentioned, may probably be Tropical America. The figures of this species, given by Chemnitz and Born, represent it as marked by several narrow bands of a rufous brown colour: but the variety here delineated, has only one, of a deep purple; it is almost the only specimen answering to this description, which we have yet seen: both varieties are very rare, and much prized by collectors. * * * * * * GENERAL INDEX _OF THE PLATES TO_ VOL. II. IN THE ORDER OF PUBLICATION. ----