The Tritons and Frog Shells - Family Tritonidae

THE TRITONS AND FROG SHELLS - FAMILY TRITONIDAE. Shell spiral, thick, with one or two varices to each whorl; aperture round, with thick lips, and anterior canal; operculum present; mantle enclosed; foot, small,, siphon short; lingual ribbon set with seven rows of teeth;' eyes on tentacles.

A large tropical family of three genera allied to Muricidx on one side, and Doliidx on the other. They subsist upon de caying animal matter and live from low water to fifty fathoms depth.

Genus TRITON, Montt: Shell ovate or oblong, with prominent elevated spire, ribbed and crossed by varices, usually few, remote, and non-continuous; columella smooth, wrinkled or nodulecli outer lip thick, and scalloped or toothed within; canal long or short, turned up; operculum horny, ovate or annular, with nucleus marginal.

A handsome tropical genus of about 150 species, including one that reaches 18 inches in length —" almost the largest of gas teropod mollusks,"- writes Tryon. Some species have world wide distribution, accounted for by the fact that the young are pelagic and free-swimming, very different creatures from the staid adult Tritons. The metamorphosis occurs some time after hatching.

"The Tritons are shells of much more solid structure than the Murices or Ranellx, and of much more simple growth. They are not furnished with any spines nor haye they any ramified branches like the Murices; the rude manner in which the whorls are convoluted seems rather to indicate that their animal inhabi tant, though possessing abundant power of calcification, is of somewhat -sluggish growth."—Reeve.

A very tough skin covered with hairs, or bristles protects the shell externally in most species. The lip curls in as the mollusk matures, forming a marginal channel which is filled with 49 The Tritons and Frog Sheila shelly material. This thickening of the lip precedes a period of rest. When growth is resumed the mantle extends the shell leaving the thickened lip behind as a varix crossing the whorl.

The apex is peculiar in structure. It is horny with a thin plating of shelly substance outside. The shell is often seen chip ped off, exposing the horny foundation.

Triton's Trumpet

(T. tritonis, Linn., T. variegatus, Lam.) is called "the Variegated Triton," by Reeve. Variegated it is, with buff, and brown, purple and red, in rich patterns suggesting the plumage of pheasants. The ground is pale; the dark colours are laid on in crescentic patches, no longer than the width of the spiral ridge they ornament. The columella is dark purplish brown, crossed by white wrinkles. The spire bears about a dozen flat varices. The outer lip is toothed, and whitish, with double streaks of brown soon fading into the ruddy aperture. The canal is short and recurved.

This is the giant Triton which reaches sixteen or eighteen inches in length. The Pacific Islanders use it for a teakettle, the operculum being the lid and the canal, the spout. The shell is hung by a wooden hook over the fire. The long spire and swollen body whorl give a sixteen-inch Triton considerable capacity.

Habitat.— New Zealand, Polynesia, Philippines, Japan, Indian Ocean.

Variety nobilis, Conr., differs from the type in being broader and heavier, with a distinct shoulder, especially noticeable on the body whorl. The first few coils of the spire are quite smooth. The aperture is pale orange. The shoulder appears only on adult shells. This is the West Indian Triton, found also in the Medi terranean and Cape Verde Islands.

The Knobbed Triton (T. nodiferus, Lam.) is a big-mouthed, stout trumpet shell, with a double row of knobs encircling its spire. Instead of becoming larger on the body whorl, the knobs fade out. There are Tritons much more noticeably knobbed than this one. The gaping throat has a pale lining. Brownish yellow tessela tions adorn the strongly ridged exterior and mark the toothed lip border. The broad, brown columella is wrinkled Above and below. Length, 5 to JO inches.