Species with tube very long, and without spines. _M. acanthopterus._ The prickly Murex. Species with three varices on each whorl. _M. melanomathos._ The black-spined Murex. Species which have whorls with more than three varices; the tube almost close. _M. lyratus._ The lyre-shaped Murex. Species sub-turreted. _M. vitulinus._ The young Murex. Species sub-globular; the spire and the canal rather short, very open; the aperture sub-effuse. 11. Triton. Thirty-one species. In this genus the varices are in longitudinal rows or series, but alternating, few in number, sometimes only one on each whorl. They are never spinous or foliated, though frequently plaited or tuberculated. The Triton variegatus type of this genus is one of the largest spiral shells. Shell oval, with spire and canal straight, middling, generally rough, garnished with varices, rare, scattered, and preserved in longitudinal rows; aperture sub-oval, elongated, terminated by a short, open canal; the columellar edge less hollowed than the right, and covered with a callosity; operculum horny, oval, rounded, and rather large. Triton variegatus. T. nodiferus. T. Australis. T. lampas. T. scrobiculator. T. Spengleri. T. corrugatus. T. succinctus. T. pilearis. T. lotorium. T. femoralis. T. subdistortus. T. cancellatus. T. maculosus. T. clandestinus. T. pyrum. T. cynocephalum. T. tripus. T. canaliferus. T. retusus. T. clavator. T. tuberosus. T. vespaceus. T. chlorostomus. T. anus. T. clathratus. T. rubecula. T. cutaceus. T. dolarius. T. Tranquebaricus. T. undosus. _T. variegatus._ The trumpet Triton. Pl. 26, fig. 5. The smoothest species, oblong, ventricose, tubiform; aperture dilated; suture of the spire crenulated; pillar lip grooved obliquely; colour pale purple, clouded and spotted with brown. _T. cutaceus._ The rough-skin Triton. Species with spire rather short, always very tuberculated, often umbilicated; a sinus at the posterior junction of the two edges. _T. anus._ The grinning Triton. Species similar to the T. cutaceus, but having the aperture surrounded by a thin dilated membrane and irregular teeth.