Inside the Cocal, two hundred yards to the westward, stretches inland a labyrinth of lagoons and mangrove swamps, impassable to most creatures save alligators and boa-constrictors.

But amid this labyrinth grow everywhere mighty trees--balatas in plenty among them, in every stage of decay; dying, seemingly, by gradual submergence of their roots, and giving a ghastly and ragged appearance to the forest.

At the mouth of the little river Nariva, a few miles down, is proof positive, unless I am much mistaken, of similar subsidence.

For there I found trees of all sizes--roseau scrub among them--standing rooted below high-tide mark; and killed where they grew.
So we rode on, stopping now and then to pick up shells; chip-chips, {274a} which are said to be excellent eating; a beautiful purple bivalve, {274b} to which, in almost every case, a coralline {274c} had attached itself, of a form quite new to me.

A lash some eighteen inches long, single or forked; purplish as long as its coat of lime--holding the polypes--still remained, but when that was rubbed off a mere round strip of dark horn; and in both cases flexible and elastic, so that it can be coiled up and tied in knots; a very curious and graceful piece of Nature's workmanship.