Volume I Part 10 (1/2)
OBS. _Testa plerumque spira elongata, apertura ad basin angustata, siphone superiore parvo aut nullo._
III. _Apertura supra ac.u.minata, extrinsecus recta, infra rotundata, dilatata, vel effusa._
_Mitrae papalis, episcopalis, &c._
OBS. _Testa plerumque laevi ad basin obtusa, truncata, labio exteriore margine crenato, gula laevi._
GENERIC CHARACTER.
Sh.e.l.l unequally fusiform; spire lengthened, attenuated; outer lip simple not toothed within. Columella plaited.
DIVISIONS.
I. Aperture narrow, linear, above angulated, below a little contracted.
_Mitrae vulpecula, plicata, &c._
OBS. Sh.e.l.l generally longitudinally plaited, equally fusiform; outer lip smooth, slightly waved; top of the inner lip much thickened within; throat striated.
II. Aperture above pointed, below narrowed, externally curved.
_Voluta mitra-abbatis._ Chemnitz, &c.
OBS. Sh.e.l.l generally with an elongated spire, the aperture below narrowed; upper syphon or channel small or wanting.
III. Aperture above pointed, externally straight, below rounded, widened or effuse.
_Mitrae papalis, episcopalis, &c._
OBS. Sh.e.l.l generally smooth, the base thick and truncated; margin of the outer lip crenated; throat smooth. The smaller sh.e.l.ls of this division connect the genera _Mitra_ and _Colombella_ (Lamarck).
SPECIFIC CHARACTER.
_M. testa angusta, basi cancellata; spira plicis carinatis; interst.i.tiis sulcis transversis confertis; columella 4-plicata; gula 4 aut 5 striis remotis._
Sh.e.l.l narrow, base cancellated. Spire with carinated plaits, the interstices with slender, crowded, transverse grooves. Pillar of four plaits; throat with four to five remote striae.
This superb sh.e.l.l is figured from a matchless specimen brought home by that ill.u.s.trious and lamented patron of science, the late Sir J. Banks, from the Pacific Ocean: it is now, together with his entire collection of sh.e.l.ls and insects, in the Museum of the Linnaean Society.
It is of great rarity, and the present specimen far exceeds in size any I have yet seen. A very perfect one exists in my father's collection which measures only two inches one line long: it differs slightly in wanting the lower white band and its inferior border: there is also an additional small plait between the second and third, a variation not uncommon in the Linnaean Volutes, and which lessens the importance of this character as a specific distinction.