One valve of the specimen above alluded to (the only one I have seen), is uncoated, and beautifully iridescent. Its country is unknown--but I think it may prove a native of the South American rivers. * * * * * Pl. 177 [Illustration] TURBINELLUS spirillus, _Carinated Turnip Shell._ * * * * * GENERIC CHARACTER. _Testa pyriformis vel fusiformis, sub-ponderosa. Apex papillosus. Columella plicata. Labium interius margine dilatatum. Canalis elongatus, rectus._ Shell pear-shaped or fusiform, heavy. Apex papillary. Pillar plaited. Interior lip with the margin dilated. Canal lengthened, straight. Generic Type. _Voluta Pyrum._ Lin. * * * * * SPECIFIC CHARACTER. _T. pyriformi; spira depressa, apice prominente; anfractu basali carinato; labio interiore dilatato, albo; columellae basi plicata._ Shell pear-shaped; spire depressed, apex prominent; basal whorl carinated, interior lip dilated, white; base of the pillar one-plaited. Murex spirillus. _Gmelin_, 3544. _Dillwyn_, 721. _Martini_, 3. _tab._ 115. _f._ 1069. _Knorr_, 6. _tab._ 24. _f._ 3. _Pyrula Spirillus._ _Lam. Syst._ 7. _p._ 142. * * * * * In assigning a situation, under the modern system, to the _Murex spirillus_ of Linnaeus, no genus appears to me more adapted for its reception than that of _Turbinellus_. These shells were formerly blended with the Linnaean Volutes, but are now detached from them as a distinct genus. The most striking peculiarity consists in the prolongation of the base into a long and straight canal; they possess, in common with the Volutes, a papillary spire, and, in general, their surface is smooth. There are, however, other shells classed by the French conchologists with this genus, from their having a plaited columella; in these, the apex of the spire is acute, the base truncated, and the outside rough with nodules or obtuse spines; characters so greatly at variance, and so very distinct from those first mentioned, that it becomes questionable whether these latter shells should not rather be classed as a distinct group: in fact, they are much more nearly allied to _Mitra_ and _Cancellaria_, which have acute spires, sculptured volutions, and truncate bases, than to the smooth _Turbinelli_, which differ so strikingly in all these particulars. This shell is common to many parts of the Indian Ocean; and, like most of the smooth _Turbinelli_, has the inner lip dilated. * * * * * Pl. 178 [Illustration] BUCEROS coronatus, _Coronated Hornbill._ * * * * * GENERIC CHARACTER. _Rostrum elongatum, crassum, inane, deflexum, marginibus obtuse crenatis, epithemate inani, forma vario, in mandibulam superiorem imposito. Nares basales, ovatae_, (_lingua brevis, angusta, acuta_. Illiger.) _Pedes gressorii._